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Air Conditioning Overflow Sensor
The Technology Transfer Office at Stennis Space Center helped a local inventor develop a prototype of an attachment for central air conditioners and heat pumps that helps monitor water levels to prevent condensation overflow. The sensor will indicate a need for drain line maintenance and prevent possible damage caused by drain pan water spillover. An engineer in the Stennis Space Center prototype Development Laboratory used SSC sensor technology in the development of the sensor.
Severson, Wayne J.
The overflow line for the reactor vessel of a liquid-metal-cooled nuclear reactor includes means for establishing and maintaining a continuous bleed flow of coolant amounting to 5 to 10% of the total coolant flow through the overflow line to prevent thermal shock to the overflow line when the reactor is restarted following a trip. Preferably a tube is disposed concentrically just inside the overflow line extending from a point just inside the reactor vessel to an overflow tank and a suction line is provided opening into the body of liquid metal in the reactor vessel and into the annulus between the overflow line and the inner tube.
DEFF Research Database (Denmark)
Hansen, Alexander Bjerremand; Midtgaard, Jan
prototype in Standard ML and integrated it into MLton as an additional optimization pass. It is able to remove 22% of the overflow checks in the MLton benchmark suite. The binary size of the programs decrease up to 10% and the run time of arithmetic heavy programs decrease significantly - in some cases up...... by the industrial-strength compiler MLton. By studying the code generated for integer arithmetic we identify dead code where overflow cannot happen. We propose a flow-sensitive integer interval analysis that detects and removes such needless overflow checks on integer arithmetic. We have implemented an analysis...
Smart Sensors Enable Smart Air Conditioning Control
Cheng, Chin-Chi; Lee, Dasheng
In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants' information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans' intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be contr...
Universal Signal Conditioning System for Amperometric Sensors
Directory of Open Access Journals (Sweden)
Full Text Available In this article the research for developing whole-cell biochips has been presented using both bioluminescent and electrochemical methods. The research was on integrating an electrode cell with both electrochemical and bioluminescent detection using a single VLSI chip. The authors have investigated the signal conditioning system that can work with any kind of amperometric and bioluminescent sensor. During this research the authors focused on the analog front-end unit. The work includes investigating the electronic model for simulation for an electrochemical cell and conceiving a fully integrated 8X8 electrochemical sensor array. The authors are focusing on signal conditioning system and its functionality. The main concern for the authors was to maintain the complexity and the number of electronic devices as low as possible.
Oil condition sensor. Interim report; Oelzustandssensor. Zwischenbericht
Energy Technology Data Exchange (ETDEWEB)
Hartwig, S.; Jaegle, M. [Fraunhofer-Inst. fuer Physikalische Messtechnik, Freiburg (Germany); Rademacher, S.; Schultheis, W. [BEDIA, Leinburg (Germany)
In the summer of 2000 the Fraunhofer Institute for physical measuring technology was tasked by the FW with a study to evaluate various measurement principles for the development of oil condition sensors. In the frame of this study, four new sensor principles were proposed for the use in engine oil. Apart from an optical measurement method (online-ATR -spectroscopy) the measurement of sensitive material - in particular metal oxides and zeolites - within the engine oil as well as a method for the determination of electrode transition resistances, which falsify the measure values, were tested. The last method has been adapted from the field of microelectronics (TLM approach, transmission line model). In the frame of the current project ''Oil condition sensor'' the feasibility of these approaches is supposed to be tested. The plan is to construct sensors for these four measurement principles, to manufacture them and to carry out the measurements. A measurement stand was especially set-up to for the last purpose of this project, which allows adjusting the operating conditions within the engine in terms of pressure, flow and temperature course as realistic as possible. This interim report provides an overview of the results, which have been obtained so far. (orig.) [German] In einer von der FW in Auftrag gegebenen Studie wurde das Fraunhofer-Institut fuer Physikalische Messtechnik im Sommer 2000 beauftragt, verschiedene Messprinzipien fuer die Entwicklung eines Oelzustandssensors zu evaluieren. Als Ergebnis wurden im Rahmen dieser Studie vier fuer den Einsatz im Motoroel neuartige Sensorprinzipien vorgeschlagen. Neben einem optischen Messverfahren (online-ATR-Spektroskopie) waren dies die Vermessung sensitiver Materialien - insbesondere Metalloxide und Zeolithe - im Motoroel, sowie ein aus der Mikroelektronik adaptiertes Verfahren zur Bestimmung von messwertverfaelschenden Elektrodenuebergangswiderstaenden (TLM-Ansatz, Transmission-Line Model). Im
Smart sensors enable smart air conditioning control.
Cheng, Chin-Chi; Lee, Dasheng
In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants' information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans' intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It's also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection.
Smart Sensors Enable Smart Air Conditioning Control
Directory of Open Access Journals (Sweden)
Chin-Chi Cheng
Full Text Available In this study, mobile phones, wearable devices, temperature and human motion detectors are integrated as smart sensors for enabling smart air conditioning control. Smart sensors obtain feedback, especially occupants' information, from mobile phones and wearable devices placed on human body. The information can be used to adjust air conditioners in advance according to humans' intentions, in so-called intention causing control. Experimental results show that the indoor temperature can be controlled accurately with errors of less than ±0.1 °C. Rapid cool down can be achieved within 2 min to the optimized indoor capacity after occupants enter a room. It's also noted that within two-hour operation the total compressor output of the smart air conditioner is 48.4% less than that of the one using On-Off control. The smart air conditioner with wearable devices could detect the human temperature and activity during sleep to determine the sleeping state and adjusting the sleeping function flexibly. The sleeping function optimized by the smart air conditioner with wearable devices could reduce the energy consumption up to 46.9% and keep the human health. The presented smart air conditioner could provide a comfortable environment and achieve the goals of energy conservation and environmental protection.
Estimation of combined sewer overflow discharge
DEFF Research Database (Denmark)
Ahm, Malte; Thorndahl, Søren Liedtke; Nielsen, Jesper Ellerbæk
weirs. It can, therefore, be a challenge to quantify the discharges from CSOs. Quantification of CSO discharges are important in relation to the increased environmental awareness of the receiving water bodies. Furthermore, CSO discharge quantification is essential for closing the rainfall-runoff mass......Combined sewer overflow (CSO) structures are constructed to effectively discharge excess water during heavy rainfall, to protect the urban drainage system from hydraulic overload. Consequently, most CSO structures are not constructed according to basic hydraulic principles for ideal measurement......-balance in combined sewer catchments. A closed mass-balance is an advantage for calibration of all urban drainage models based on mass-balance principles. This study presents three different software sensor concepts based on local water level sensors, which can be used to estimate CSO discharge volumes from hydraulic...
Muscular condition monitoring system using fiber bragg grating sensors
Energy Technology Data Exchange (ETDEWEB)
Kim, Heon Young; Lee, Jin Hyuk; Kim, Dae Hyun [Seoul National University of Technology, Seoul (Korea, Republic of)
Fiber optic sensors (FOS) have advantages such as electromagnetic interference (EMI) immunity, corrosion resistance and multiplexing capability. For these reasons, they are widely used in various condition monitoring systems (CMS). This study investigated a muscular condition monitoring system using fiber optic sensors (FOS). Generally, sensors for monitoring the condition of the human body are based on electro-magnetic devices. However, such an electrical system has several weaknesses, including the potential for electro-magnetic interference and distortion. Fiber Bragg grating (FBG) sensors overcome these weaknesses, along with simplifying the devices and increasing user convenience. To measure the level of muscle contraction and relaxation, which indicates the muscle condition, a belt-shaped FBG sensor module that makes it possible to monitor the movement of muscles in the radial and circumferential directions was fabricated in this study. In addition, a uniaxial tensile test was carried out in order to evaluate the applicability of this FBG sensor module. Based on the experimental results, a relationship was observed between the tensile stress and Bragg wavelength of the FBG sensors, which revealed the possibility of fabricating a muscular condition monitoring system based on FBG sensors.
Air condition sensor on KNX network
Gecova, Katerina; Vala, David; Slanina, Zdenek; Walendziuk, Wojciech
One of the main goals of modern buildings in addition to the management environment is also attempt to save energy. For this reason, increased demands on the prevention of energy loss, which can be expressed for example as an inefficient use of the available functions as a building or heat leakage. Reducing heat loss as a perfect tightness of doors and windows in the building, however, restricts the natural ventilation, which leads to a gradual deterioration of the quality of the internal environment. This state then has a very significant impact on human health. In the closed, poorly ventilated area, the person staying at increasing the carbon dioxide concentration, temperature and humidity, which impacts the human thermoregulation system, increases fatigue and causes restlessness. It is therefore necessary to monitor these parameters and then control so as to ensure stable and optimal human values. The aim is to design and implementation Module sensors that will be able to measure different parameters, allowing the subsequent regulation of indoor environmental quality.
Measuring intracellular redox conditions using GFP-based sensors
DEFF Research Database (Denmark)
Björnberg, Olof; Ostergaard, Henrik; Winther, Jakob R
Recent years have seen the development of methods for analyzing the redox conditions in specific compartments in living cells. These methods are based on genetically encoded sensors comprising variants of Green Fluorescent Protein in which vicinal cysteine residues have been introduced at solvent......-exposed positions. Several mutant forms have been identified in which formation of a disulfide bond between these cysteine residues results in changes of their fluorescence properties. The redox sensors have been characterized biochemically and found to behave differently, both spectroscopically and in terms...... of redox properties. As genetically encoded sensors they can be expressed in living cells and used for analysis of intracellular redox conditions; however, which parameters are measured depends on how the sensors interact with various cellular redox components. Results of both biochemical and cell...
A suite of optical fibre sensors for structural condition monitoring
Sun, T.; Grattan, K. T. V.; Carlton, J.
This paper is to review the research activities at City University London in the development of a range of fibre Bragg grating (FBG)-based sensors, including strain, temperature, relative humidity, vibration and acoustic sensors, with an aim to meet the increasing demands from industry for structural condition monitoring. As a result, arrays of optical fibre sensors have been instrumented into various types of structures, including concrete, limestone, marine propellers, pantograph and electrical motors, allowing for both static and dynamic monitoring and thus enhanced structural reliability and integrity.
Some Experiences with Numerical Modelling of Overflows
DEFF Research Database (Denmark)
Larsen, Torben; Nielsen, L.; Jensen, B.
and reliable formulas for the estimation of overflows have been derived. Numerical modelling of overflows is significantly more complicated than standard 1-dimensional river or sewer modelling. The problem is usually managed by incorporating the mentioned empirical formulas in the numerical models......Overflows are commonly applied in storm sewer systems to control flow and water surface level. Therefore overflows play a central role in the control of discharges of pollutants from sewer systems to the environment. The basic hydrodynamic principle of an overflow is the so-called critical flow...... across the edge of the overflow. To ensure critical flow across the edge, the upstream flow must be subcritical whereas the downstream flow is either supercritical or a free jet. Experimentally overflows are well studied. Based on laboratory experiments and Froude number scaling, numerous accurate...
Enabling Smart Air Conditioning by Sensor Development: A Review.
Cheng, Chin-Chi; Lee, Dasheng
The study investigates the development of sensors, in particular the use of thermo-fluidic sensors and occupancy detectors, to achieve smart operation of air conditioning systems. Smart operation refers to the operation of air conditioners by the reinforcement of interaction to achieve both thermal comfort and energy efficiency. Sensors related to thermal comfort include those of temperature, humidity, and pressure and wind velocity anemometers. Improvements in their performance in the past years have been studied by a literature survey. Traditional occupancy detection using passive infra-red (PIR) sensors and novel methodologies using smartphones and wearable sensors are both discussed. Referring to the case studies summarized in this study, air conditioning energy savings are evaluated quantitatively. Results show that energy savings of air conditioners before 2000 was 11%, and 30% after 2000 by the integration of thermo-fluidic sensors and occupancy detectors. By utilizing wearable sensing to detect the human motions, metabolic rates and related information, the energy savings can reach up to 46.3% and keep the minimum change of predicted mean vote (∆PMV→0), which means there is no compromise in thermal comfort. This enables smart air conditioning to compensate for the large variations from person to person in terms of physiological and psychological satisfaction, and find an optimal temperature for everyone in a given space. However, this tendency should be evidenced by more experimental results in the future.
Enabling Smart Air Conditioning by Sensor Development: A Review
Cheng, Chin-Chi; Lee, Dasheng
The study investigates the development of sensors, in particular the use of thermo-fluidic sensors and occupancy detectors, to achieve smart operation of air conditioning systems. Smart operation refers to the operation of air conditioners by the reinforcement of interaction to achieve both thermal comfort and energy efficiency. Sensors related to thermal comfort include those of temperature, humidity, and pressure and wind velocity anemometers. Improvements in their performance in the past years have been studied by a literature survey. Traditional occupancy detection using passive infra-red (PIR) sensors and novel methodologies using smartphones and wearable sensors are both discussed. Referring to the case studies summarized in this study, air conditioning energy savings are evaluated quantitatively. Results show that energy savings of air conditioners before 2000 was 11%, and 30% after 2000 by the integration of thermo-fluidic sensors and occupancy detectors. By utilizing wearable sensing to detect the human motions, metabolic rates and related information, the energy savings can reach up to 46.3% and keep the minimum change of predicted mean vote (∆PMV→0), which means there is no compromise in thermal comfort. This enables smart air conditioning to compensate for the large variations from person to person in terms of physiological and psychological satisfaction, and find an optimal temperature for everyone in a given space. However, this tendency should be evidenced by more experimental results in the future. PMID:27916906
Enabling Smart Air Conditioning by Sensor Development: A Review
Directory of Open Access Journals (Sweden)
Chin-Chi Cheng
Full Text Available The study investigates the development of sensors, in particular the use of thermo-fluidic sensors and occupancy detectors, to achieve smart operation of air conditioning systems. Smart operation refers to the operation of air conditioners by the reinforcement of interaction to achieve both thermal comfort and energy efficiency. Sensors related to thermal comfort include those of temperature, humidity, and pressure and wind velocity anemometers. Improvements in their performance in the past years have been studied by a literature survey. Traditional occupancy detection using passive infra-red (PIR sensors and novel methodologies using smartphones and wearable sensors are both discussed. Referring to the case studies summarized in this study, air conditioning energy savings are evaluated quantitatively. Results show that energy savings of air conditioners before 2000 was 11%, and 30% after 2000 by the integration of thermo-fluidic sensors and occupancy detectors. By utilizing wearable sensing to detect the human motions, metabolic rates and related information, the energy savings can reach up to 46.3% and keep the minimum change of predicted mean vote (∆PMV→0, which means there is no compromise in thermal comfort. This enables smart air conditioning to compensate for the large variations from person to person in terms of physiological and psychological satisfaction, and find an optimal temperature for everyone in a given space. However, this tendency should be evidenced by more experimental results in the future.
Corrosion Sensor Development for Condition-Based Maintenance of Aircraft
Directory of Open Access Journals (Sweden)
Gino Rinaldi
Full Text Available Aircraft routinely operate in atmospheric environments that, over time, will impact their structural integrity. Material protection and selection schemes notwithstanding, recurrent exposure to chlorides, pollution, temperature gradients, and moisture provide the necessary electrochemical conditions for the development and profusion of corrosion in aircraft structures. For aircraft operators, this becomes an important safety matter as corrosion found in a given aircraft must be assumed to be present in all of that type of aircraft. This safety protocol and its associated unscheduled maintenance requirement drive up the operational costs of the fleet and limit the availability of the aircraft. Hence, there is an opportunity at present for developing novel sensing technologies and schemes to aid in shifting time-based maintenance schedules towards condition-based maintenance procedures. In this work, part of the ongoing development of a multiparameter integrated corrosion sensor is presented. It consists of carbon nanotube/polyaniline polymer sensors and commercial-off-the-shelf sensors. It is being developed primarily for monitoring environmental and material factors for the purpose of providing a means to more accurately assess the structural integrity of aerospace aluminium alloys through fusion of multiparameter sensor data. Preliminary experimental test results are presented for chloride ion concentration, hydrogen gas evolution, humidity variations, and material degradation.
Design of a Modular Signal Conditioning Circuit for Biopotential Sensors
Winncy Y. DU; Winston JOSE; Jake ASKELAND
Biosignal conditioning (BC) is critical in biomedical instruments because it directly affects measurement accuracy, reliability, and repeatability. BC also presents a great challenge due to the small amplitude of biosignals and their ease of corruption with noise and other disturbances. This paper describes a modular BC system developed for biopotential sensors that can preserve useful information while removing unwanted noise and interference components. This BC circuit includes an instrumen...
Control of Computer Room Air Conditioning using IT Equipment Sensors
Energy Technology Data Exchange (ETDEWEB)
Bell, Geoffrey C.; Storey, Bill; Patterson, Michael K.
The goal of this demonstration was to show how sensors in IT equipment could be accessed and used to directly control computer room air conditioning. The data provided from the sensors is available on the IT network and the challenge for this project was to connect this information to the computer room air handler's control system. A control strategy was developed to enable separate control of the chilled water flow and the fans in the computer room air handlers. By using these existing sensors in the IT equipment, an additional control system is eliminated (or could be redundant) and optimal cooling can be provided saving significant energy. Using onboard server temperature sensors will yield significant energy reductions in data centers. Intel hosted the demonstration in its Santa Clara, CA data center. Intel collaborated with IBM, HP, Emerson, Wunderlich-Malec Engineers, FieldServer Technologies, and LBNL to install the necessary components and develop the new control scheme. LBNL also validated the results of the demonstration.
Climate impacts of parameterized Nordic Sea overflows
Danabasoglu, Gokhan; Large, William G.; Briegleb, Bruce P.
A new overflow parameterization (OFP) of density-driven flows through ocean ridges via narrow, unresolved channels has been developed and implemented in the ocean component of the Community Climate System Model version 4. It represents exchanges from the Nordic Seas and the Antarctic shelves, associated entrainment, and subsequent injection of overflow product waters into the abyssal basins. We investigate the effects of the parameterized Denmark Strait (DS) and Faroe Bank Channel (FBC) overflows on the ocean circulation, showing their impacts on the Atlantic Meridional Overturning Circulation and the North Atlantic climate. The OFP is based on the Marginal Sea Boundary Condition scheme of Price and Yang (1998), but there are significant differences that are described in detail. Two uncoupled (ocean-only) and two fully coupled simulations are analyzed. Each pair consists of one case with the OFP and a control case without this parameterization. In both uncoupled and coupled experiments, the parameterized DS and FBC source volume transports are within the range of observed estimates. The entrainment volume transports remain lower than observational estimates, leading to lower than observed product volume transports. Due to low entrainment, the product and source water properties are too similar. The DS and FBC overflow temperature and salinity properties are in better agreement with observations in the uncoupled case than in the coupled simulation, likely reflecting surface flux differences. The most significant impact of the OFP is the improved North Atlantic Deep Water penetration depth, leading to a much better comparison with the observational data and significantly reducing the chronic, shallow penetration depth bias in level coordinate models. This improvement is due to the deeper penetration of the southward flowing Deep Western Boundary Current. In comparison with control experiments without the OFP, the abyssal ventilation rates increase in the North
Interger multiplication with overflow detection or saturation
Energy Technology Data Exchange (ETDEWEB)
Schulte, M.J.; Balzola, P.I.; Akkas, A.; Brocato, R.W.
High-speed multiplication is frequently used in general-purpose and application-specific computer systems. These systems often support integer multiplication, where two n-bit integers are multiplied to produce a 2n-bit product. To prevent growth in word length, processors typically return the n least significant bits of the product and a flag that indicates whether or not overflow has occurred. Alternatively, some processors saturate results that overflow to the most positive or most negative representable number. This paper presents efficient methods for performing unsigned or two's complement integer multiplication with overflow detection or saturation. These methods have significantly less area and delay than conventional methods for integer multiplication with overflow detection and saturation.
Diagnosing overflow waters in the North Atlantic
Guo, Chuncheng; Ilicak, Mehmet; Bentsen, Mats; Fer, Ilker
Danmark Strait overflow water (DSOW) and Iceland Faroe overflow water (ISOW) are important for the formation and transformation of deep waters in the North Atlantic. In this work the volume transport, variability, and pathways of DSOW and ISOW are diagnosed using the one degree ocean-ice coupled Norwegian Earth System Model (NorESM) that is forced by CORE2 inter-annual forcing. The oceanic component (MICOM) features an isopycnal coordinate that is referenced to 2000 db. The issues related to the coarse resolution such as the southward transport of ISOW to the western European Basin, the lack of overflow water in the western North Atlantic, and the western boundary detachment of the deep western boundary current are addressed. The effects of diapycnal mixing on the behavior of overflow descent at Denmark Strait and Faroe Bank Channel and its downstream evolution are examined.
Sensor Technology Baseline Study for Enabling Condition Based Maintenance Plus in Army Ground Vehicles
for enabling condition based maintenance plus in Army ground vehicles. The sensor study was driven from Failure Mode Effects Analysis ( FMEA ...of Tables Table 1. Sensor technology baseline study based on engine FMEA report. ...................................5 Table 2. Sensor technology...baseline study based on transmission FMEA report. .........................8 Table 3. Sensor technology baseline study based on alternator FMEA report
Application of Ultrasonic Sensors in Road Surface Condition Distinction Methods
Directory of Open Access Journals (Sweden)
Shota Nakashima
Full Text Available The number of accidents involving elderly individuals has been increasing with the increase of the aging population, posing increasingly serious challenges. Most accidents are caused by reduced judgment and physical abilities, which lead to severe consequences. Therefore, studies on support systems for elderly and visually impaired people to improve the safety and quality of daily life are attracting considerable attention. In this study, a road surface condition distinction method using reflection intensities obtained by an ultrasonic sensor was proposed. The proposed method was applied to movement support systems for elderly and visually impaired individuals to detect dangerous road surfaces and give an alarm. The method did not perform well in previous studies of puddle detection, because the alert provided by the method did not enable users to avoid puddles. This study extended the method proposed by previous studies with respect to puddle detection ability. The findings indicate the effectiveness of the proposed method by considering four road surface conditions. The proposed method could detect puddle conditions. The effectiveness of the proposed method was verified in all four conditions, since users could differentiate between road surface conditions and classify the conditions as either safe or dangerous.
Application of Ultrasonic Sensors in Road Surface Condition Distinction Methods.
Nakashima, Shota; Aramaki, Shingo; Kitazono, Yuhki; Mu, Shenglin; Tanaka, Kanya; Serikawa, Seiichi
The number of accidents involving elderly individuals has been increasing with the increase of the aging population, posing increasingly serious challenges. Most accidents are caused by reduced judgment and physical abilities, which lead to severe consequences. Therefore, studies on support systems for elderly and visually impaired people to improve the safety and quality of daily life are attracting considerable attention. In this study, a road surface condition distinction method using reflection intensities obtained by an ultrasonic sensor was proposed. The proposed method was applied to movement support systems for elderly and visually impaired individuals to detect dangerous road surfaces and give an alarm. The method did not perform well in previous studies of puddle detection, because the alert provided by the method did not enable users to avoid puddles. This study extended the method proposed by previous studies with respect to puddle detection ability. The findings indicate the effectiveness of the proposed method by considering four road surface conditions. The proposed method could detect puddle conditions. The effectiveness of the proposed method was verified in all four conditions, since users could differentiate between road surface conditions and classify the conditions as either safe or dangerous.
Research on Overflow Monitoring Mechanism Based on Downhole Microflow Detection
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Liang Ge
Full Text Available The flow rate variation of the drilling fluid and micro-overflow loss is difficult to analyze. The purpose to prevent the occurrence of kick, lost circulation, and other complex conditions is not easy to be achieved. Therefore, the microflow-induced annulus multiphase flow rate and annulus pressure field model were studied, and a downhole microflow measurement system has been developed. A differential pressure type flow measurement was used in the system, and real-time downhole information was obtained to achieve deep, narrow windows and other safety-density complex formation security. This paper introduced a new bottom-hole flow meter which can measure the annular flux while drilling and monitor overflow and circulation loss. The accuracy and reliability of the MPD (managed pressure drilling system can be improved obviously by applying the device; as a result, the safety of drilling is enhanced and the cost is reduced.
Influence of Conditions of Pd/SnO2 Nanomaterial Formation on Properties of Hydrogen Sensors
Sokovykh, E. V.; Oleksenko, L. P.; Maksymovych, N. P.; Matushko, I. P.
Metal oxide sensors were created using nanosized tin dioxide obtained by a sol-gel method. Gas-sensitive layers of the sensors were impregnated with PdCl2 solutions of different concentrations to increase sensitivities of the proposed sensors. Influence of different temperature conditions of the sensor formation on the sensor properties was studied. It was found that decreasing duration of high-temperature sensor treatment prevents enlargement of particles of the gas-sensitive materials. It was shown that the sensors based on materials with smaller particle sizes showed higher sensor responses to 40 ppm H2. Obtained results were explained in terms of substantial influence of length of the common boundaries between the material particles of tin dioxide and palladium on the gas-sensitive properties of the sensors. The obtained sensors had possessed a fast response and recovery time and demonstrated stable characteristics during their long-term operation.
Design of a Modular Signal Conditioning Circuit for Biopotential Sensors
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Winncy Y. DU
Full Text Available Biosignal conditioning (BC is critical in biomedical instruments because it directly affects measurement accuracy, reliability, and repeatability. BC also presents a great challenge due to the small amplitude of biosignals and their ease of corruption with noise and other disturbances. This paper describes a modular BC system developed for biopotential sensors that can preserve useful information while removing unwanted noise and interference components. This BC circuit includes an instrumentation amplifier, an active 1st-order high-pass filter with Sallen-Key configuration, a 5th-order low-pass Bessel filter, and a 2nd-order Twin-T notch filter. The order of these filters and the associated components in each filter can be easily changed to adapt to different biosignals (modular feature. Data acquisition and sampling were performed using a USB6009 module with a built-in A/D converter. Testing of a real electrocardiogram on the designed signal conditioning circuit demonstrated comparable outputs to commercial devices.
Micromachined capacitive pressure sensor with signal conditioning electronics
DEFF Research Database (Denmark)
Fragiacomo, Giulio
Micromachined capacitive pressure sensors for harsh environment together with interfacing electronic circuits have been studied in this project. Micro-electromechanical systems (MEMS) have been proposed as substitutes for macro scale sensor's systems in many different fields and are the only...... a great deal of sensors are used. Pressure sensors are among the most successful MEMS and are used in a huge variety of applications. In this project an absolute capacitive pressure sensor has been developed with the aim to integrate it in pump control systems to improve the efficiency of the pump...
Low power sensor network for wireless condition monitoring
Richter, Ch.; Frankenstein, B.; Schubert, L.; Weihnacht, B.; Friedmann, H.; Ebert, C.
For comprehensive fatigue tests and surveillance of large scale structures, a vibration monitoring system working in the Hz and sub Hz frequency range was realized and tested. The system is based on a wireless sensor network and focuses especially on the realization of a low power measurement, signal processing and communication. Regarding the development, we met the challenge of synchronizing the wireless connected sensor nodes with sufficient accuracy. The sensor nodes ware realized by compact, sensor near signal processing structures containing components for analog preprocessing of acoustic signals, their digitization, algorithms for data reduction and network communication. The core component is a digital micro controller which performs the basic algorithms necessary for the data acquisition synchronization and the filtering. As a first application, the system was installed in a rotor blade of a wind power turbine in order to monitor the Eigen modes over a longer period of time. Currently the sensor nodes are battery powered.
Optimization of Overflow Policies in Call Centers
DEFF Research Database (Denmark)
Koole, G.M.; Nielsen, B.F.; Nielsen, T.B.
We examine how overflow policies in a multi-skill call center should be designed to accommodate performance measures that depend on waiting time percentiles such as service level. This is done using a discrete Markovian approximation of the waiting time of the first customers waiting in line...... and customers are treated in a FCFS order....
Time series modelling of overflow structures
DEFF Research Database (Denmark)
Carstensen, J.; Harremoës, P.
to the overflow structures. The capacity of a pump draining the storage pipe has been estimated for two rain events, revealing that the pump was malfunctioning during the first rain event. The grey-box modelling approach is applicable for automated on-line surveillance and control. (C) 1997 IAWQ. Published...
Comparison of Suspended Solid Separation in Advanced Storm Overflow Structures
DEFF Research Database (Denmark)
Larsen, Torben; Sørensen, Morten Steen
This paper describes a laboratory investigation of the separation of suspended solids in a circular weir overflow and a vortex separator. The basic idea is to evaluate the efficiency of a vortical flow in the overflow chamber, and to compare these results with other overflow structures....
Model studies of dense water overflows in the Faroese Channels
Cuthbertson, Alan; Davies, Peter; Stashchuk, Nataliya; Vlasenko, Vasiliy
The overflow of dense water from the Nordic Seas through the Faroese Channel system was investigated through combined laboratory experiments and numerical simulations using the Massachusetts Institute of Technology General Circulation Model. In the experimental study, a scaled, topographic representation of the Faroe-Shetland Channel, Wyville-Thomson Basin and Ridge and Faroe Bank Channel seabed bathymetry was constructed and mounted in a rotating tank. A series of parametric experiments was conducted using dye-tracing and drogue-tracking techniques to investigate deep-water overflow pathways and circulation patterns within the modelled region. In addition, the structure of the outflowing dense bottom water was investigated through density profiling along three cross-channel transects located in the Wyville-Thomson Basin and the converging, up-sloping approach to the Faroe Bank Channel. Results from the dye-tracing studies demonstrate a range of parametric conditions under which dense water overflow across the Wyville-Thomson Ridge is shown to occur, as defined by the Burger number, a non-dimensional length ratio and a dimensionless dense water volume flux parameter specified at the Faroe-Shetland Channel inlet boundary. Drogue-tracking measurements reveal the complex nature of flow paths and circulations generated in the modelled topography, particularly the development of a large anti-cyclonic gyre in the Wyville-Thompson Basin and up-sloping approach to the Faroe Bank Channel, which diverts the dense water outflow from the Faroese shelf towards the Wyville-Thomson Ridge, potentially promoting dense water spillage across the ridge itself. The presence of this circulation is also indicated by associated undulations in density isopycnals across the Wyville-Thomson Basin. Numerical simulations of parametric test cases for the main outflow pathways and density structure in a similarly-scaled Faroese Channels model domain indicate excellent qualitative agreement with
Extensive exometabolome analysis reveals extended overflow metabolism in various microorganisms
Directory of Open Access Journals (Sweden)
Paczia Nicole
Full Text Available Abstract Overflow metabolism is well known for yeast, bacteria and mammalian cells. It typically occurs under glucose excess conditions and is characterized by excretions of by-products such as ethanol, acetate or lactate. This phenomenon, also denoted the short-term Crabtree effect, has been extensively studied over the past few decades, however, its basic regulatory mechanism and functional role in metabolism is still unknown. Here we present a comprehensive quantitative and time-dependent analysis of the exometabolome of Escherichia coli, Corynebacterium glutamicum, Bacillus licheniformis, and Saccharomyces cerevisiae during well-controlled bioreactor cultivations. Most surprisingly, in all cases a great diversity of central metabolic intermediates and amino acids is found in the culture medium with extracellular concentrations varying in the micromolar range. Different hypotheses for these observations are formulated and experimentally tested. As a result, the intermediates in the culture medium during batch growth must originate from passive or active transportation due to a new phenomenon termed "extended" overflow metabolism. Moreover, we provide broad evidence that this could be a common feature of all microorganism species when cultivated under conditions of carbon excess and non-inhibited carbon uptake. In turn, this finding has consequences for metabolite balancing and, particularly, for intracellular metabolite quantification and 13C-metabolic flux analysis.
Overflow Concentration and Sedimentation in Hoppers
DEFF Research Database (Denmark)
Hjelmager Jensen, Jacob; Saremi, Sina
as a result of different timescales in the segregation of the various sediment fractions. The heavier constituents in a mixture will have had time to settle, and overflowing sediments are therefore primarily composed of the finer and lighter constituents, whose concentrations potentially exceed those...... at the inflow. The hopper constitutes a complex system despite its geometrical regularity; the complexities are largely from the settling processes in concentrated polydisperse mixtures. These settling processes can, however, be captured by employing available settling formulas applicable for multifractional...... mixtures, the former analytically. Although assumptions tied to the mathematical model are fulfilled best for hoppers rigged with a multiple-inflow system, the model accurately predicts measured concentrations in the final stage of overflow for single-inflow systems. The model can be used...
OVERFLOW Simulations of Space Shuttle Orbiter Reentry Based on As-Built Geometry
Ma, Edward C.; Vicker, Darby J.; Campbell, Charles H.; Wilson, Brad; Pavek, Mike; Berger, Karen
The Space Shuttle Orbiters Discovery and Endeavor have been digitally scanned to obtain outer mold line surfaces. Using these scans, the existing overset computational fluid dynamics (CFD) grid system will be modified by projecting the grid points to the scanned geometry. Simulations will be performed using the OVERFLOW solver and the results compared to previous OVERFLOW results on the theoretical geometry and the aerodynamic databook. The "bent airframe" term will be compared between the aerodynamic databook and the computations over a range of reentry conditions.
Touch mode micromachined capacitive pressure sensor with signal conditioning electronics
DEFF Research Database (Denmark)
Fragiacomo, Giulio; Eriksen, Gert F.; Christensen, Carsten
technology to design and fabricate these sensors has been implemented. Capacitive pressure sensing, on the other hand, is still an open and really promising field. Results Capacitive microsensors were designed and fabricated (Fig. 1) and an analytical model for touch mode regime, which fitted accurately...
角田, 裕紀; KAKUTA, Hironori
This paper describes a study of condition monitoring in water pipe using vibration sensor. The vibration sensor composed of condenser microphone is placed at water pipe. This sensor picks up vibration by water flow. We estimate of flow rate from the output voltage waveform. It is high cost that any conventional flowmeter which use at outside pipe such as ultrasonic flowmeter. We develop a lower cost system and make measurement of flow rate in water pipe easier. The validity of sensing pipe vi...
Condition monitoring of helical gears using automated selection of features and sensors
Alkhadafe, H; Al-Habaibeh, A; Lotfi, A
The selection of most sensitive sensors and signal processing methods is essential process for the design of condition monitoring and intelligent fault diagnosis and prognostic systems. Normally, sensory data includes high level of noise and irrelevant or red undant information which makes the selection of the most sensitive sensor and signal processing method a difficult task. This paper introduces a new application of the Automated Sensor and Signal Processing Approach (ASPS), for the desig...
Effective Sensor Selection and Data Anomaly Detection for Condition Monitoring of Aircraft Engines
Directory of Open Access Journals (Sweden)
Liansheng Liu
Full Text Available In a complex system, condition monitoring (CM can collect the system working status. The condition is mainly sensed by the pre-deployed sensors in/on the system. Most existing works study how to utilize the condition information to predict the upcoming anomalies, faults, or failures. There is also some research which focuses on the faults or anomalies of the sensing element (i.e., sensor to enhance the system reliability. However, existing approaches ignore the correlation between sensor selecting strategy and data anomaly detection, which can also improve the system reliability. To address this issue, we study a new scheme which includes sensor selection strategy and data anomaly detection by utilizing information theory and Gaussian Process Regression (GPR. The sensors that are more appropriate for the system CM are first selected. Then, mutual information is utilized to weight the correlation among different sensors. The anomaly detection is carried out by using the correlation of sensor data. The sensor data sets that are utilized to carry out the evaluation are provided by National Aeronautics and Space Administration (NASA Ames Research Center and have been used as Prognostics and Health Management (PHM challenge data in 2008. By comparing the two different sensor selection strategies, the effectiveness of selection method on data anomaly detection is proved.
Effective Sensor Selection and Data Anomaly Detection for Condition Monitoring of Aircraft Engines.
Liu, Liansheng; Liu, Datong; Zhang, Yujie; Peng, Yu
In a complex system, condition monitoring (CM) can collect the system working status. The condition is mainly sensed by the pre-deployed sensors in/on the system. Most existing works study how to utilize the condition information to predict the upcoming anomalies, faults, or failures. There is also some research which focuses on the faults or anomalies of the sensing element (i.e., sensor) to enhance the system reliability. However, existing approaches ignore the correlation between sensor selecting strategy and data anomaly detection, which can also improve the system reliability. To address this issue, we study a new scheme which includes sensor selection strategy and data anomaly detection by utilizing information theory and Gaussian Process Regression (GPR). The sensors that are more appropriate for the system CM are first selected. Then, mutual information is utilized to weight the correlation among different sensors. The anomaly detection is carried out by using the correlation of sensor data. The sensor data sets that are utilized to carry out the evaluation are provided by National Aeronautics and Space Administration (NASA) Ames Research Center and have been used as Prognostics and Health Management (PHM) challenge data in 2008. By comparing the two different sensor selection strategies, the effectiveness of selection method on data anomaly detection is proved.
Impact Analysis of Temperature and Humidity Conditions on Electrochemical Sensor Response in Ambient Air Quality Monitoring.
Wei, Peng; Ning, Zhi; Ye, Sheng; Sun, Li; Yang, Fenhuan; Wong, Ka Chun; Westerdahl, Dane; Louie, Peter K K
The increasing applications of low-cost air sensors promises more convenient and cost-effective systems for air monitoring in many places and under many conditions. However, the data quality from such systems has not been fully characterized and may not meet user expectations in research and regulatory uses, or for use in citizen science. In our study, electrochemical sensors (Alphasense B4 series) for carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO₂), and oxidants (O x ) were evaluated under controlled laboratory conditions to identify the influencing factors and quantify their relation with sensor outputs. Based on the laboratory tests, we developed different correction methods to compensate for the impact of ambient conditions. Further, the sensors were assembled into a monitoring system and tested in ambient conditions in Hong Kong side-by-side with regulatory reference monitors, and data from these tests were used to evaluate the performance of the models, to refine them, and validate their applicability in variable ambient conditions in the field. The more comprehensive correction models demonstrated enhanced performance when compared with uncorrected data. One over-arching observation of this study is that the low-cost sensors may promise excellent sensitivity and performance, but it is essential for users to understand and account for several key factors that may strongly affect the nature of sensor data. In this paper, we also evaluated factors of multi-month stability, temperature, and humidity, and considered the interaction of oxidant gases NO₂ and ozone on a newly introduced oxidant sensor.
Impact Damage Localisation with Piezoelectric Sensors under Operational and Environmental Conditions
National Research Council Canada - National Science Library
Mohammad Saleh Salmanpour; Zahra Sharif Khodaei; M H Ferri Aliabadi
Guided-wave structural health monitoring (SHM) systems with piezoelectric sensors are investigated for localisation of barely visible impact damage in CFRP plates under vibration and different thermal conditions...
Signal conditioning and processing for metallic Hall sensors.
Czech Academy of Sciences Publication Activity Database
Entler, Slavomír; Ďuran, Ivan; Sládek, P.; Vayakis, G.; Kočan, M.
Roč. 123, November (2017), s. 783-786 ISSN 0920-3796. [SOFT 2016: Symposium on Fusion Technology /29./. Prague, 05.09.2016-09.09.2016] R&D Projects: GA MŠk LG14002 Institutional support: RVO:61389021 Keywords : Hall sensor * Lock-in * Synchronous detection * Current spinning * Hall effect * Planar hall effect suppression Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.319, year: 2016 http://www.sciencedirect.com/science/article/pii/S0920379617305070
Condition monitoring through advanced sensor and computational technology : final report (January 2002 to May 2005).
Energy Technology Data Exchange (ETDEWEB)
Kim, Jung-Taek (Korea Atomic Energy Research Institute, Daejon, Korea); Luk, Vincent K.
The overall goal of this joint research project was to develop and demonstrate advanced sensors and computational technology for continuous monitoring of the condition of components, structures, and systems in advanced and next-generation nuclear power plants (NPPs). This project included investigating and adapting several advanced sensor technologies from Korean and US national laboratory research communities, some of which were developed and applied in non-nuclear industries. The project team investigated and developed sophisticated signal processing, noise reduction, and pattern recognition techniques and algorithms. The researchers installed sensors and conducted condition monitoring tests on two test loops, a check valve (an active component) and a piping elbow (a passive component), to demonstrate the feasibility of using advanced sensors and computational technology to achieve the project goal. Acoustic emission (AE) devices, optical fiber sensors, accelerometers, and ultrasonic transducers (UTs) were used to detect mechanical vibratory response of check valve and piping elbow in normal and degraded configurations. Chemical sensors were also installed to monitor the water chemistry in the piping elbow test loop. Analysis results of processed sensor data indicate that it is feasible to differentiate between the normal and degraded (with selected degradation mechanisms) configurations of these two components from the acquired sensor signals, but it is questionable that these methods can reliably identify the level and type of degradation. Additional research and development efforts are needed to refine the differentiation techniques and to reduce the level of uncertainties.
High-Density Fiber Optical Sensor and Instrumentation for Gas Turbine Operation Condition Monitoring
Directory of Open Access Journals (Sweden)
Hua Xia
Full Text Available Gas turbine operation control is normally based on thermocouple-measured exhaust temperatures. Due to radiation shielding and bulky package, it is difficult to provide high spatial resolution for measuring can-to-can combustion temperature profile at the exhaust duct. This paper has demonstrated that wavelength-division-multiplexing-based fiber Bragg grating sensors could provide high spatial resolution steady and dynamic temperature measurements. A robust sensor package can be designed with either circumferential sensing cable or radial sensing rake for quasi-distributing multiple fiber sensors in the gas turbine environment. The field validations have demonstrated that quasi-distributed fiber sensors have not only demonstrated its temperature measurement accuracy compared to existing thermocouple sensors but also shown its unique dynamic response amplitude and power spectra that could be utilized for gas turbine transient operation condition monitoring and diagnostics.
Electrodermal Activity Sensor for Classification of Calm/Distress Condition.
Zangróniz, Roberto; Martínez-Rodrigo, Arturo; Pastor, José Manuel; López, María T; Fernández-Caballero, Antonio
This article introduces a new and unobtrusive wearable monitoring device based on electrodermal activity (EDA) to be used in health-related computing systems. This paper introduces the description of the wearable device capable of acquiring the EDA of a subject in order to detect his/her calm/distress condition from the acquired physiological signals. The lightweight wearable device is placed in the wrist of the subject to allow continuous physiological measurements. With the aim of validating the correct operation of the wearable EDA device, pictures from the International Affective Picture System are used in a control experiment involving fifty participants. The collected signals are processed, features are extracted and a statistical analysis is performed on the calm/distress condition classification. The results show that the wearable device solely based on EDA signal processing reports around 89% accuracy when distinguishing calm condition from distress condition.
Electrodermal Activity Sensor for Classification of Calm/Distress Condition
Directory of Open Access Journals (Sweden)
Roberto Zangróniz
Full Text Available This article introduces a new and unobtrusive wearable monitoring device based on electrodermal activity (EDA to be used in health-related computing systems. This paper introduces the description of the wearable device capable of acquiring the EDA of a subject in order to detect his/her calm/distress condition from the acquired physiological signals. The lightweight wearable device is placed in the wrist of the subject to allow continuous physiological measurements. With the aim of validating the correct operation of the wearable EDA device, pictures from the International Affective Picture System are used in a control experiment involving fifty participants. The collected signals are processed, features are extracted and a statistical analysis is performed on the calm/distress condition classification. The results show that the wearable device solely based on EDA signal processing reports around 89% accuracy when distinguishing calm condition from distress condition.
Systems with selective overflow and change of bandwidth
DEFF Research Database (Denmark)
Iversen, Villy Bæk
on the overflow group, we show by balance equations that the number of calls of each service will be Multinomial distributed with probabilities proportional with the arrival rates. Using a recent result of Newcomer & al, we then find moments (done up to fourth order) of individual overflow streams or any...
The 8 July 2002 storm over Athens: analysis of the Kifissos River/Canal overflows
Directory of Open Access Journals (Sweden)
K. Mazi
Full Text Available We analyse the flood event of 8 July 2002 that caused overflows over portions of the lower reach of the Kifissos River/Canal. The storm covered only the lower basin area and was concentrated on the centre and the southwest side of Greater Athens. The issue that stirred the public opinion was whether the hydraulic works underway in lower Kifissos at that time were responsible for the overflows. We explore this issue with the hydrologic-hydraulic model of the Kifissos basin TELESIM. To shed light on the probable cause of the observed flooding, we ran TELESIM for two rain-field scenarios derived from the recorded point-rainfalls, computing flows for each scenario. Depth profiles for channel conditions without obstructions do not explain the observed flooding. With the channel taken as locally obstructed by flow-area reducing ramps plus bed-debris, estimated nominal overflows (bank-full level is threshold, but the water stays inside the channel compare well with actual ones for the milder rainfall scenario. Hence, the simulations support as plausible the hypothesis that flow obstructions due to the construction caused the overflows.
Construction Condition and Damage Monitoring of Post-Tensioned PSC Girders Using Embedded Sensors.
Shin, Kyung-Joon; Lee, Seong-Cheol; Kim, Yun Yong; Kim, Jae-Min; Park, Seunghee; Lee, Hwanwoo
The potential for monitoring the construction of post-tensioned concrete beams and detecting damage to the beams under loading conditions was investigated through an experimental program. First, embedded sensors were investigated that could measure pre-stress from the fabrication process to a failure condition. Four types of sensors were installed on a steel frame, and the applicability and the accuracy of these sensors were tested while pre-stress was applied to a tendon in the steel frame. As a result, a tri-sensor loading plate and a Fiber Bragg Grating (FBG) sensor were selected as possible candidates. With those sensors, two pre-stressed concrete flexural beams were fabricated and tested. The pre-stress of the tendons was monitored during the construction and loading processes. Through the test, it was proven that the variation in thepre-stress had been successfully monitored throughout the construction process. The losses of pre-stress that occurred during a jacking and storage process, even those which occurred inside the concrete, were measured successfully. The results of the loading test showed that tendon stress and strain within the pure span significantly increased, while the stress in areas near the anchors was almost constant. These results prove that FBG sensors installed in a middle section can be used to monitor the strain within, and the damage to pre-stressed concrete beams.
Conditions With High Intracellular Glucose Inhibit Sensing Through Glucose Sensor Snf3 in Saccharomyces cerevisiae
DEFF Research Database (Denmark)
Karhumaa, Kaisa; Wu, B.Q.; Kielland-Brandt, Morten
Gene expression in micro-organisms is regulated according to extracellular conditions and nutrient concentrations. In Saccharomyces cerevisiae, non-transporting sensors with high sequence similarity to transporters, that is, transporter-like sensors, have been identified for sugars as well...... of extracellular glucose to Snf3 was measured for cells grown in non-fermentative medium or on maltose. The apparent affinity for glucose was lowest when the intracellular glucose concentration was high. The results conform to an alternating-access model for transporter-like sensors. J. Cell. Biochem. 110: 920...
Thick-film acoustic emission sensors for use in structurally integrated condition-monitoring applications.
Pickwell, Andrew J; Dorey, Robert A; Mba, David
Monitoring the condition of complex engineering structures is an important aspect of modern engineering, eliminating unnecessary work and enabling planned maintenance, preventing failure. Acoustic emissions (AE) testing is one method of implementing continuous nondestructive structural health monitoring. A novel thick-film (17.6 μm) AE sensor is presented. Lead zirconate titanate thick films were fabricated using a powder/sol composite ink deposition technique and mechanically patterned to form a discrete thick-film piezoelectric AE sensor. The thick-film sensor was benchmarked against a commercial AE device and was found to exhibit comparable responses to simulated acoustic emissions.
Development of an In-Situ Decommissioning Sensor Network Test Bed for Structural Condition Monitoring - 12156
Energy Technology Data Exchange (ETDEWEB)
Zeigler, Kristine E.; Ferguson, Blythe A. [Savannah River National Laboratory, Aiken, South Carolina 29808 (United States)
The Savannah River National Laboratory (SRNL) has established an In Situ Decommissioning (ISD) Sensor Network Test Bed, a unique, small scale, configurable environment, for the assessment of prospective sensors on actual ISD system material, at minimal cost. The Department of Energy (DOE) is presently implementing permanent entombment of contaminated, large nuclear structures via ISD. The ISD end state consists of a grout-filled concrete civil structure within the concrete frame of the original building. Validation of ISD system performance models and verification of actual system conditions can be achieved through the development a system of sensors to monitor the materials and condition of the structure. The ISD Sensor Network Test Bed has been designed and deployed to addresses the DOE-Environmental Management Technology Need to develop a remote monitoring system to determine and verify ISD system performance. Commercial off-the-shelf sensors have been installed on concrete blocks taken from walls of the P Reactor Building at the Savannah River Site. Deployment of this low-cost structural monitoring system provides hands-on experience with sensor networks. The initial sensor system consists of groutable thermistors for temperature and moisture monitoring, strain gauges for crack growth monitoring, tilt-meters for settlement monitoring, and a communication system for data collection. Baseline data and lessons learned from system design and installation and initial field testing will be utilized for future ISD sensor network development and deployment. The Sensor Network Test Bed at SRNL uses COTS sensors on concrete blocks from the outer wall of the P Reactor Building to measure conditions expected to occur in ISD structures. Knowledge and lessons learned gained from installation, testing, and monitoring of the equipment will be applied to sensor installation in a meso-scale test bed at FIU and in future ISD structures. The initial data collected from the sensors
Electrodermal Activity Sensor for Classification of Calm/Distress Condition
National Research Council Canada - National Science Library
Roberto Zangróniz; Arturo Martínez-Rodrigo; Jose Manuel Pastor; María T López; Antonio Fernandez-Caballero
...) to be used in health-related computing systems. This paper introduces the description of the wearable device capable of acquiring the EDA of a subject in order to detect his/her calm/distress condition from the acquired physiological signals...
Feature Extraction from Sensor Data Streams for Optimizing Grinding Condition
Kondo, Y.; Higashimoto, Y.; Sakamoto, S.; Fujita, T.; Yamaguchi, K.
A visualization method for time-series sensing data was designed to optimize grinding condition. The fluctuation pattern of time-series data streams can be visualized as a white and black pattern by utilizing the spindle power change rate average. The designed visualization method was applied to a condition monitoring in lapping operation. The relation between the fallout abrasive grain content and lapping behaviour was experimentally examined. In the lapping with grinding fluid containing no fallout abrasive, the spindle power decreased in a monotone manner with lapping time, while in the lapping with fallout abrasive, the spindle power decreased with lapping time up to 20s of lapping and then tended to converge on a constant value. The spindle power change rate average displayed as a white and black pattern reproduced the changes of spindle power very well. The appearance probability of white or black pattern has a strong relation with the fallout abrasive content and the designed data processing scheme could make possible to predict the grinding fluid condition from the easy-handling grinding test.
Model-Based Sensor Placement for Component Condition Monitoring and Fault Diagnosis in Fossil Energy Systems
Energy Technology Data Exchange (ETDEWEB)
Mobed, Parham [Texas Tech Univ., Lubbock, TX (United States); Pednekar, Pratik [West Virginia Univ., Morgantown, WV (United States); Bhattacharyya, Debangsu [West Virginia Univ., Morgantown, WV (United States); Turton, Richard [West Virginia Univ., Morgantown, WV (United States); Rengaswamy, Raghunathan [Texas Tech Univ., Lubbock, TX (United States)
Design and operation of energy producing, near "zero-emission" coal plants has become a national imperative. This report on model-based sensor placement describes a transformative two-tier approach to identify the optimum placement, number, and type of sensors for condition monitoring and fault diagnosis in fossil energy system operations. The algorithms are tested on a high fidelity model of the integrated gasification combined cycle (IGCC) plant. For a condition monitoring network, whether equipment should be considered at a unit level or a systems level depends upon the criticality of the process equipment, its likeliness to fail, and the level of resolution desired for any specific failure. Because of the presence of a high fidelity model at the unit level, a sensor network can be designed to monitor the spatial profile of the states and estimate fault severity levels. In an IGCC plant, besides the gasifier, the sour water gas shift (WGS) reactor plays an important role. In view of this, condition monitoring of the sour WGS reactor is considered at the unit level, while a detailed plant-wide model of gasification island, including sour WGS reactor and the Selexol process, is considered for fault diagnosis at the system-level. Finally, the developed algorithms unify the two levels and identifies an optimal sensor network that maximizes the effectiveness of the overall system-level fault diagnosis and component-level condition monitoring. This work could have a major impact on the design and operation of future fossil energy plants, particularly at the grassroots level where the sensor network is yet to be identified. In addition, the same algorithms developed in this report can be further enhanced to be used in retrofits, where the objectives could be upgrade (addition of more sensors) and relocation of existing sensors.
Model Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant
Energy Technology Data Exchange (ETDEWEB)
Kumar, Rajeeva; Kumar, Aditya; Dai, Dan; Seenumani, Gayathri; Down, John; Lopez, Rodrigo
This report summarizes the achievements and final results of this program. The objective of this program is to develop a general model-based sensor network design methodology and tools to address key issues in the design of an optimal sensor network configuration: the type, location and number of sensors used in a network, for online condition monitoring. In particular, the focus in this work is to develop software tools for optimal sensor placement (OSP) and use these tools to design optimal sensor network configuration for online condition monitoring of gasifier refractory wear and radiant syngas cooler (RSC) fouling. The methodology developed will be applicable to sensing system design for online condition monitoring for broad range of applications. The overall approach consists of (i) defining condition monitoring requirement in terms of OSP and mapping these requirements in mathematical terms for OSP algorithm, (ii) analyzing trade-off of alternate OSP algorithms, down selecting the most relevant ones and developing them for IGCC applications (iii) enhancing the gasifier and RSC models as required by OSP algorithms, (iv) applying the developed OSP algorithm to design the optimal sensor network required for the condition monitoring of an IGCC gasifier refractory and RSC fouling. Two key requirements for OSP for condition monitoring are desired precision for the monitoring variables (e.g. refractory wear) and reliability of the proposed sensor network in the presence of expected sensor failures. The OSP problem is naturally posed within a Kalman filtering approach as an integer programming problem where the key requirements of precision and reliability are imposed as constraints. The optimization is performed over the overall network cost. Based on extensive literature survey two formulations were identified as being relevant to OSP for condition monitoring; one based on LMI formulation and the other being standard INLP formulation. Various algorithms to solve
Feasibility of Fiber Bragg Grating and Long-Period Fiber Grating Sensors under Different Environmental Conditions
Directory of Open Access Journals (Sweden)
Jian-Neng Wang
Full Text Available This paper presents the feasibility of utilizing fiber Bragg grating (FBG and long-period fiber grating (LPFG sensors for nondestructive evaluation (NDE of infrastructures using Portland cement concretes and asphalt mixtures for temperature, strain, and liquid-level monitoring. The use of hybrid FBG and LPFG sensors is aimed at utilizing the advantages of two kinds of fiber grating to implement NDE for monitoring strains or displacements, temperatures, and water-levels of infrastructures such as bridges, pavements, or reservoirs for under different environmental conditions. Temperature fluctuation and stability tests were examined using FBG and LPFG sensors bonded on the surface of asphalt and concrete specimens. Random walk coefficient (RWC and bias stability (BS were used for the first time to indicate the stability performance of fiber grating sensors. The random walk coefficients of temperature variations between FBG (or LPFG sensor and a thermocouple were found in the range of −0.7499 °C/ to −1.3548 °C/. In addition, the bias stability for temperature variations, during the fluctuation and stability tests with FBG (or LPFG sensors were within the range of 0.01 °C/h with a 15–18 h time cluster to 0.09 °C/h with a 3–4 h time cluster. This shows that the performance of FBG or LPFG sensors is comparable with that of conventional high-resolution thermocouple sensors under rugged conditions. The strain measurement for infrastructure materials was conducted using a packaged FBG sensor bonded on the surface of an asphalt specimen under indirect tensile loading conditions. A finite element modeling (FEM was applied to compare experimental results of indirect tensile FBG strain measurements. For a comparative analysis between experiment and simulation, the FEM numerical results agreed with those from FBG strain measurements. The results of the liquid-level sensing tests show the LPFG-based sensor could discriminate five stationary liquid
Corrosion sensor for monitoring the service condition of chloride-contaminated cement mortar.
Lu, Shuang; Ba, Heng-Jing
A corrosion sensor for monitoring the corrosion state of cover mortar was developed. The sensor was tested in cement mortar, with and without the addition of chloride to simulate the adverse effects of chloride-contaminated environmental conditions on concrete structures. In brief, a linear polarization resistance method combined with an embeddable reference electrode was utilized to measure the polarization resistance (Rp) using built-in sensor electrodes. Subsequently, electrochemical impedance spectroscopy in the frequency range of 1 kHz to 50 kHz was used to obtain the cement mortar resistance (Rs). The results show that the polarization resistance is related to the chloride content and Rs; ln (Rp) is linearly related to the Rs values in mortar without added chloride. The relationships observed between the Rp of the steel anodes and the resistance of the surrounding cement mortar measured by the corrosion sensor confirms that Rs can indicate the corrosion state of concrete structures.
Survivability of integrated PVDF film sensors to accelerated ageing conditions in aeronautical/aerospace structures
Guzman, E.; Cugnoni, J.; Gmür, T.; Bonhôte, P.; Schorderet, A.
This work validates the use of integrated polyvinylidene fluoride (PVDF) film sensors for dynamic testing, even after being subjected to UV-thermo-hygro-mechanical accelerated ageing conditions. The verification of PVDF sensors' survivability in these environmental conditions, typically confronted by civil and military aircraft, is the main concern of the study. The evaluation of survivability is made by a comparison of dynamic testing results provided by the PVDF patch sensors subjected to an accelerated ageing protocol, and those provided by neutral non-aged sensors (accelerometers). The available measurements are the time-domain response signals issued from a modal analysis procedure, and the corresponding frequency response functions (FRF). These are in turn used to identify the constitutive properties of the samples by extraction of the modal parameters, in particular the natural frequencies. The composite specimens in this study undergo different accelerated ageing processes. After several weeks of experimentation, the samples exhibit a loss of stiffness, represented by a decrease in the elastic moduli down to 10%. Despite the ageing, the integrated PVDF sensors, subjected to the same ageing conditions, are still capable of providing reliable data to carry out a close followup of these changes. This survivability is a determinant asset in order to use integrated PVDF sensors to perform structural health monitoring (SHM) in the future of full-scale composite aeronautical structures.
Directory of Open Access Journals (Sweden)
Sainov Mihail Petrovich
Full Text Available The article has data on potential designs of overflow structures made of soil rather than concrete. The most reliable and cheap ones are dykes made of sandbags. This viewpoint is substantiated by the operation of peatland irrigation systems, constructed in the Moscow region in 2011 — 2012. The construction of overflow sandbag dykes must have slope/riverbed protection structures to withstand their erosion by open and filtration flows of the downstream. Designs of overflow dykes having their downstream sides protected by geosynthetic coats, which are patented by other hydraulic engineers, have proven unreliable.
Simultaneous Fault Detection and Sensor Selection for Condition Monitoring of Wind Turbines
Directory of Open Access Journals (Sweden)
Wenna Zhang
Full Text Available Data collected from the supervisory control and data acquisition (SCADA system are used widely in wind farms to obtain operation and performance information about wind turbines. The paper presents a three-way model by means of parallel factor analysis (PARAFAC for wind turbine fault detection and sensor selection, and evaluates the method with SCADA data obtained from an operational farm. The main characteristic of this new approach is that it can be used to simultaneously explore measurement sample profiles and sensors profiles to avoid discarding potentially relevant information for feature extraction. With K-means clustering method, the measurement data indicating normal, fault and alarm conditions of the wind turbines can be identified, and the sensor array can be optimised for effective condition monitoring.
Wireless acceleration sensor of moving elements for condition monitoring of mechanisms
Sinitsin, Vladimir V.; Shestakov, Aleksandr L.
Comprehensive analysis of the angular and linear accelerations of moving elements (shafts, gears) allows an increase in the quality of the condition monitoring of mechanisms. However, existing tools and methods measure either linear or angular acceleration with postprocessing. This paper suggests a new construction design of an angular acceleration sensor for moving elements. The sensor is mounted on a moving element and, among other things, the data transfer and electric power supply are carried out wirelessly. In addition, the authors introduce a method for processing the received information which makes it possible to divide the measured acceleration into the angular and linear components. The design has been validated by the results of laboratory tests of an experimental model of the sensor. The study has shown that this method provides a definite separation of the measured acceleration into linear and angular components, even in noise. This research contributes an advance in the range of methods and tools for condition monitoring of mechanisms.
Energy Technology Data Exchange (ETDEWEB)
Zeigler, K.; Ferguson, B.; Karapatakis, D.; Herbst, C.; Stripling, C.
The P Reactor at the Savannah River Site is one of the first reactor facilities in the US DOE complex that has been placed in its end state through in situ decommissioning (ISD). The ISD end state consists of a grout-filled concrete civil structure within the concrete frame of the original building. To evaluate the feasibility and utility of remote sensors to provide verification of ISD system conditions and performance characteristics, an ISD Sensor Network Test Bed has been designed and deployed at the Savannah River National Laboratory. The test bed addresses the DOE-EM Technology Need to develop a remote monitoring system to determine and verify ISD system performance. Commercial off-the-shelf sensors have been installed on concrete blocks taken from walls of the P Reactor Building. Deployment of this low-cost structural monitoring system provides hands-on experience with sensor networks. The initial sensor system consists of: (1) Groutable thermistors for temperature and moisture monitoring; (2) Strain gauges for crack growth monitoring; (3) Tiltmeters for settlement monitoring; and (4) A communication system for data collection. Preliminary baseline data and lessons learned from system design and installation and initial field testing will be utilized for future ISD sensor network development and deployment.
Energy-autonomous wireless vibration sensor for condition-based maintenance of machinery
Wang, Z.; Bouwens, F.; Vullers, R.; Petré, F.; Devos, S.
This paper addresses the development of an energy-autonomous wireless vibration sensor for condition-based monitoring of machinery. Such technology plays an increasingly important role in modern manufacturing industry. In this work, energy harvesting is realized by resorting to a custom designed
Fault Diagnosis and Condition Monitoring of an All Geared Lathe Machine Using Piezoelectric Sensor
Directory of Open Access Journals (Sweden)
Amiya BHAUMIK
Full Text Available Undesired vibrations are serious problems that affect and deteriorate the quality of the product. This paper investigates dynamic and vibrational characteristics of a newly installed All Geared Lathe Machine with piezoelectric sensor. A comparison is drawn with the data measured and acceptable data as per ISO 10816 and thus concluded that the machine is in working condition.
Evolution of the Sensor Fish Device for Measuring Physical Conditions in Severe Hydraulic Environments
Energy Technology Data Exchange (ETDEWEB)
Carlson, Thomas J.; Duncan, Joanne P.
To assist in deriving biological specifications for design of turbine rehabilitation measures, new ''fish-friendly'' turbines, and spillway designs and operations, scientists at the Pacific Northwest National Laboratory (PNNL) have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. The Sensor Fish was developed with the support of the U.S. Department of Energy's Advanced Hydropower Turbine System program. Field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.
Staticly Detect Stack Overflow Vulnerabilities with Taint Analysis
Directory of Open Access Journals (Sweden)
Xing Zhang
Full Text Available Nowadays binary static analysis uses dangerous system library function to detect stack overflow vulnerary in program and there is no effective way to dig out the function which can cause stack overflow issue. List necessarily characteristics of the function which may cause stack overflow vulnerary and define stack overflow dangerous function(SODF. Then introduce static taint analysis to detect SODF include taint introduction, taint propagation and taint checking stragety. Next describe the particular process of detecting SODF in the program with static taint analysis. Finally choose 4 runtime library and 2 binary software, and detect whether the chosen software has SODF and locate the name of SODF with static taint analysis. Testing result shows that the algorithm can detect and locate plenty of SODF in test program which means the algorithm can work efficiently.
Locations of Combined Sewer Overflow Outfalls - US EPA Region 3
U.S. Environmental Protection Agency — This data layer identifies the locations of Combined sewer overflow outfalls. Combined sewer systems are sewers that are designed to collect rainwater runoff,...
Multiservice Switching Networks with Overflow Links and Resource Reservation
Directory of Open Access Journals (Sweden)
Mariusz Głąbowski
Full Text Available This paper proposes a new analytical model of a multiservice switching network with overflow links in the first stage and resource reservation for selected call classes in output directions. The proposed model assumes that both the overflow mechanism and the resource reservation mechanism can be used in a number of selected, or all, classes of calls. A particular attention is given to the way the effective availability parameter for networks with overflow links in the point-to-point selection mode is determined. The proposed model makes it possible to determine dependencies between the internal blocking probability, capacity of overflow links, and the number of reserved resources for call classes to be analysed. Simulation experiments confirm high accuracy of the proposed method and potential applications of the model in engineering issues.
Orion Launch Abort Vehicle Separation Analysis Using OVERFLOW
Booth, Tom
This slide presentation reviews the use of OVERFLOW, a flow solver, to analyze the effect of separation for a launch abort vehicle (i.e., Orion capsule) if required. Included in the presentation are views of the geometry, and the Overset grids, listing of the assumptions, the general run strategy, inputs into the Overflow solver, the required computational resources, the results of the convergence study. Charts and graphics are presented to show the results.
Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil
Directory of Open Access Journals (Sweden)
Markus S. Rauscher
Full Text Available The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit.
Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil.
Rauscher, Markus S; Tremmel, Anton J; Schardt, Michael; Koch, Alexander W
The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit.
Tolerable Time-Varying Overflow on Grass-Covered Slopes
Directory of Open Access Journals (Sweden)
Steven A. Hughes
Full Text Available Engineers require estimates of tolerable overtopping limits for grass-covered levees, dikes, and embankments that might experience steady overflow. Realistic tolerance estimates can be used for both resilient design and risk assessment. A simple framework is developed for estimating tolerable overtopping on grass-covered slopes caused by slowly-varying (in time overtopping discharge (e.g., events like storm surges or river flood waves. The framework adapts the well-known Hewlett curves of tolerable limiting velocity as a function of overflow duration. It has been hypothesized that the form of the Hewlett curves suggests that the grass erosion process is governed by the flow work on the slope above a critical threshold velocity (referred to as excess work, and the tolerable erosional limit is reached when the cumulative excess work exceeds a given value determined from the time-dependent Hewlett curves. The cumulative excess work is expressed in terms of overflow discharge above a critical discharge that slowly varies in time, similar to a discharge hydrograph. The methodology is easily applied using forecast storm surge hydrographs at specific locations where wave action is minimal. For preliminary planning purposes, when storm surge hydrographs are unavailable, hypothetical equations for the water level and overflow discharge hydrographs are proposed in terms of the values at maximum overflow and the total duration of overflow. An example application is given to illustrate use of the methodology.
Performances of Three Miniature Bio-inspired Optic Flow Sensors under Natural Conditions
Directory of Open Access Journals (Sweden)
Stéphane Viollet
Full Text Available Considerable attention has been paid during the last decade to vision-based navigation systems based on optic flow (OF cues. OF-based systems have been implemented on an increasingly large number of sighted autonomous robotic platforms. Nowadays, the OF is measured using conventional cameras, custom-made sensors and even optical mouse chips. However, very few studies have dealt so far with the reliability of these OF sensors in terms of their precision, range and sensitivity to illuminance variations. Three miniature custom-made OF sensors developed at our laboratory, which were composed of photosensors connected to an OF processing unit were tested and compared in this study, focusing on their responses and characteristics in real indoor and outdoor environments in a large range of illuminance. It was concluded that by combining a custom-made aVLSI retina equipped with Adaptive Pixels for Insect-based Sensor (APIS with a bio-inspired visual processing system, it is possible to obtain highly effective miniature sensors for measuring the OF under real environmental conditions.
Studying the Effect of Deposition Conditions on the Performance and Reliability of MEMS Gas Sensors
Directory of Open Access Journals (Sweden)
Walied Moussa
Full Text Available In this paper, the reliability of a micro-electro-mechanical system (MEMS-based gas sensor has been investigated using Three Dimensional (3D coupled multiphysics Finite Element (FE analysis. The coupled field analysis involved a two-way sequential electro- thermal fields coupling and a one-way sequential thermal-structural fields coupling. An automated substructuring code was developed to reduce the computational cost involved in simulating this complicated coupled multiphysics FE analysis by up to 76 percent. The substructured multiphysics model was then used to conduct a parametric study of the MEMS-based gas sensor performance in response to the variations expected in the thermal and mechanical characteristics of thin films layers composing the sensing MEMS device generated at various stages of the microfabrication process. Whenever possible, the appropriate deposition variables were correlated in the current work to the design parameters, with good accuracy, for optimum operation conditions of the gas sensor. This is used to establish a set of design rules, using linear and nonlinear empirical relations, which can be utilized in real-time at the design and development decision-making stages of similar gas sensors to enable the microfabrication of these sensors with reliable operation.
Integrated Instrumentation and Sensor Systems Enabling Condition-Based Maintenance of Aerospace Equipment
Directory of Open Access Journals (Sweden)
Richard C. Millar
Full Text Available The objective of the work reported herein was to use a systems engineering approach to guide development of integrated instrumentation/sensor systems (IISS incorporating communications, interconnections, and signal acquisition. These require enhanced suitability and effectiveness for diagnostics and health management of aerospace equipment governed by the principles of Condition-based maintenance (CBM. It is concluded that the systems engineering approach to IISS definition provided clear benefits in identifying overall system requirements and an architectural framework for categorizing and evaluating alternative architectures, relative to a bottom up focus on sensor technology blind to system level user needs. CBM IISS imperatives identified include factors such as tolerance of the bulk of aerospace equipment operational environments, low intrusiveness, rapid reconfiguration, and affordable life cycle costs. The functional features identified include interrogation of the variety of sensor types and interfaces common in aerospace equipment applications over multiplexed communication media with flexibility to allow rapid system reconfiguration to adapt to evolving sensor needs. This implies standardized interfaces at the sensor location (preferably to open standards, reduced wire/connector pin count in harnesses (or their elimination through use of wireless communications.
Compound Event Barrier Coverage in Wireless Sensor Networks under Multi-Constraint Conditions
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Yaoming Zhuang
Full Text Available It is important to monitor compound event by barrier coverage issues in wireless sensor networks (WSNs. Compound event barrier coverage (CEBC is a novel coverage problem. Unlike traditional ones, the data of compound event barrier coverage comes from different types of sensors. It will be subject to multiple constraints under complex conditions in real-world applications. The main objective of this paper is to design an efficient algorithm for complex conditions that can combine the compound event confidence. Moreover, a multiplier method based on an active-set strategy (ASMP is proposed to optimize the multiple constraints in compound event barrier coverage. The algorithm can calculate the coverage ratio efficiently and allocate the sensor resources reasonably in compound event barrier coverage. The proposed algorithm can simplify complex problems to reduce the computational load of the network and improve the network efficiency. The simulation results demonstrate that the proposed algorithm is more effective and efficient than existing methods, especially in the allocation of sensor resources.
Evolution of the sensor fish device for measuring physical conditions in sever hydraulic environments
Energy Technology Data Exchange (ETDEWEB)
Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Duncan, J. P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
To assist in deriving biological specifications for design of turbine rehabilitation measures, new "fish-friendly" turbines, and spillway designs and operations, Pacific Northwest National Laboratory (PNNL) scientists have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. This report discusses the development and field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River, which have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.
Improved signal conditioning circuit design for ionic polymer transducers as sensors
Akle, Barbar J.; Zahi, Nakad
Several researchers are actively studying Ionomeric polymer transducers (IPT) as a large strain low voltage Electro- Active Polymer (EAP) actuator. EAPs are devices that do not contain any moving parts leading to a potential large life time. Furthermore, they are light weight and flexible. IPT have the ability to generate bending strains on the order 5% when +2V potential is applied across its thickness. As sensors however, IPTs are proven to be superior compared to any other EAP material when a charge amplifier is used as a signal conditioner. Furthermore, researchers has developed miniature sensors from IPTs that could be flush mounted to a surface and measure shear stresses due to fluid flow at even low Reynolds numbers. Sensor resolution is on the order of 10 mPa enables it to be useful as a wall shear stress sensor for several aero/hydrodynamic and biomedical applications. In this paper a new signal conditioning circuit is designed with superior sensing capabilities compared to the old circuit. In the new circuit the IPT is biased with a small voltage on the order of 5mV to 25 mV. Initial experimental results demonstrated 30% enhancement in signal to noise ratio compared to the old circuit. Furthermore, this circuit enables the use of IPT polymers with larger capacitance compared to the previous circuits. Akle et al. demonstrated that the capacitance of an ionic polymer transducer is proportional to transducer performance. Ionic polymers are generally made of an ion exchange membrane, typically Nafion, coated with a flexible electrode. In this study the Direct Assembly Process (DAP) is used for the fabrication of IPT. The DAP consists of mixing a metal particulate with an ionomer solution and spraying it directly on a diluent saturated ion conducting membrane. The thickness of the electrode is controlled by altering the amount of the ionomer/metal mix sprayed on the membrane. Thicker electrodes provide IPT with a larger capacitance, and hence larger
Energy Technology Data Exchange (ETDEWEB)
Jensen, H. [PBI-Dansensor A/S (Denmark); Toft Soerensen, O. [Risoe National Lab., Materials Research Dept. (Denmark)
A new type of ceramic oxygen sensors based on semiconducting oxides was developed in this project. The advantage of these sensors compared to standard ZrO{sub 2} sensors is that they do not require a reference gas and that they can be produced in small sizes. The sensor design and the techniques developed for production of these sensors are judged suitable by the participating industry for a niche production of a new generation of oxygen sensors. Materials research on new oxygen ion conducting conductors both for applications in oxygen sensors and in fuel was also performed in this project and finally a new process was developed for fabrication of ceramic tubes by dip-coating. (EHS)
Pigorsch, Enrico
This is the 5th edition of the Metra Martech Directory "EUROPEAN CENTRES OF EXPERTISE - SENSORS." The entries represent a survey of European sensors development. The new edition contains 425 detailed profiles of companies and research institutions in 22 countries. This is reflected in the diversity of sensors development programmes described, from sensors for physical parameters to biosensors and intelligent sensor systems. We do not claim that all European organisations developing sensors are included, but this is a good cross section from an invited list of participants. If you see gaps or omissions, or would like your organisation to be included, please send details. The data base invites the formation of effective joint ventures by identifying and providing access to specific areas in which organisations offer collaboration. This issue is recognised to be of great importance and most entrants include details of collaboration offered and sought. We hope the directory on Sensors will help you to find the ri...
Noise modeling in a signal conditioning circuit for low power audio application using resistive sensor
Directory of Open Access Journals (Sweden)
Meillère Stéphane
Full Text Available Piezoresistive sensors convert a physical value into a resistance variation. Often four resistive elements are connected together in a Wheatstone bridge to provide electrical variations of sensors. When this structure is biased with a fixed voltage source or a current source the topology provides a differential output voltage. To exploit information a conditioning circuit is associated to the bridge. In most cases it consists of an instrumentation amplifier followed by a data converter to obtain very quickly a digital representation of information. Due to the high input impedance of the instrumentation amplifier, bridge sensitivity is preserved. A filter may be added to avoid aliasing or a continuous time sigma-delta modulator that includes filtering feature. This study is concerning the conditioning structure for piezoresistive sensors bridge especially fully integrated microphones for biomedical application. The bridge signal to noise ratio is set by biasing the amplifier stage by current. The noise performance becomes the limiting factor of the read-out circuit. Current mode topologies drive amplifiers design where inputs are the main noise contributor. Modeling noise contribution is a key point in the design of the conditioning circuit. The current consumption leads noise performances too. A proposed architecture was implemented in a 65nm CMOS standard technology for performance measurement and evaluation with nanowire based microphone dedicated to hearing aids application.
Wireless microwave acoustic sensor system for condition monitoring in power plant environments
Energy Technology Data Exchange (ETDEWEB)
Pereira da Cunha, Mauricio [Univ. of Maine, Orno, ME (United States)
This project successfully demonstrated novel wireless microwave acoustic temperature and pressure sensors that can be embedded into equipment and structures located in fossil fuel power plant environments to monitor the condition of components such as steam headers, re-heat lines, water walls, burner tubes, and power turbines. The wireless microwave acoustic sensor technology researched and developed through a collaborative partnership between the University of Maine and Environetix Technologies Corporation can provide a revolutionary impact in the power industry since it is anticipated that the wireless sensors will deliver reliable real-time sensing information in harsh power plant conditions that involve temperatures up to 1100oC and pressures up to 750 psi. The work involved the research and development of novel high temperature harsh environment thin film electrodes, piezoelectric smart microwave acoustic sensing elements, sensor encapsulation materials that were engineered to function over long times up to 1100oC, and a radio-frequency (RF) wireless interrogation electronics unit that are located both inside and outside the high temperature harsh environment. The UMaine / Environetix team have interacted with diverse power plant facilities, and identified as a testbed a local power generation facility, which burns municipal solid waste (MSW), the Penobscot Energy Recovery Company (PERC), Orrington, Maine. In this facility Environetix / UMaine successfully implemented and tested multiple wireless temperature sensor systems within the harsh-environment of the economizer chamber and at the boiler tubes, transferring the developed technology to the power plant environment to perform real-time sensor monitoring experiments under typical operating conditions, as initially targeted in the project. The wireless microwave acoustic sensor technology developed under this project for power plant applications offers several significant advantages including wireless
Insight into fiber Bragg sensor response at 100-MHz interrogation rates under various dynamic loading conditions
Rodriguez, George; Jaime, Marcelo; Mielke, Chuck H.; Balakirev, Fedor F.; Azad, Abul; Sandberg, Richard L.; Marshall, Bruce; La Lone, Brandon M.; Henson, Bryan F.; Smilowitz, Laura; Marr-Lyon, Mark; Sandoval, Tom
A 100 MHz fiber Bragg grating (FBG) interrogation system is described and applied to strain, pressure, and shock position sensing. The approach relies on coherent pulse illumination of the FBG sensor with a broadband short pulse from a femtosecond modelocked erbium fiber laser. After interrogation of the FBG sensor, a long multi-kilometer run of single mode fiber was used for chromatic dispersion to temporally stretch the spectral components of the reflected pulse from the FBG sensor. Dynamic strain or pressure induced spectral shifts in the FBG sensor were detected as a pulsed time domain waveform shift after encoding by the chromatic dispersive line. Signals were recorded using a single 35 GHz photodetector and a 25 GHz bandwidth digitizing oscilloscope. Application of this approach to high-speed strain sensing of magnetic materials in pulsed magnetic fields to ~150 T is demonstrated. The FBG wavelength shifts were used to study magnetic field driven magnetostriction effects in LaCoO3. A sub-microsecond temporal shift in the FBG sensor wavelength attached to the sample under first order phase change appears as a fractional length change (strain: ΔL/L<10-4) in the material. A second application to FBG sensing of pressure dynamics to nearly 2 GPa in the thermal ignition of the high explosive PBX-9501 is also demonstrated. Then, as final demonstration, we use a chirped FBG (CFBG) to resolve shock propagation dynamics in 1-D from an explosive detonation that produces fragmentation in an inert confinement vessel. These applications demonstrate the use of this FBG interrogation system in dynamical extreme conditions that would otherwise not be possible using traditional FBG interrogation approaches that are deemed too slow to resolve such events.
A new oil debris sensor for online condition monitoring of wind turbine gearboxes
DEFF Research Database (Denmark)
Wang, Chao; Liu, Hui; Liu, Xiao
Online Condition Monitoring (CM) is a key technology for the Operation and Maintenance (O&M) of wind turbines. Lubricating oil is the blood of the wind turbine gearbox. Metal debris in lubricating oil contains abundant information regarding the ageing and wear/damage of mechanical transmission...... systems. The health condition of the wind turbine gearboxes can be indicated by the quantity and size of the metal abrasive particles, which may provide very early warnings of faults/failures and benefit the condition based maintenance of the system. An improved inductive sensor probe is proposed...... in this paper for the online health monitoring of wind turbine gearbox. The magnetic field homogeneity as well as the performance of the proposed Helmholtz-coil probe are analyzed and verified by finite element analysis....
Sensor set-up for wireless measurement of automotive rim and wheel parameters in laboratory conditions
Borecki, M.; Prus, P.; Korwin-Pawlowski, M. L.; Rychlik, A.; Kozubel, W.
Modern rims and wheels are tested at the design and production stages. Tests can be performed in laboratory conditions and on the ride. In the laboratory, complex and costly equipment is used, as for example wheel balancers and impact testers. Modern wheel balancers are equipped with electronic and electro-mechanical units that enable touch-less measurement of dimensions, including precision measurement of radial and lateral wheel run-out, automatic positioning and application of the counterweights, and vehicle wheel set monitoring - tread wear, drift angles and run-out unbalance. Those tests are performed by on-wheel axis measurements with laser distance meters. The impact tester enables dropping of weights from a defined height onto a wheel. Test criteria are the loss of pressure of the tire and generation of cracks in the wheel without direct impact of the falling weights. In the present paper, a set up composed of three accelerometers, a temperature sensor and a pressure sensor is examined as the base of a wheel tester. The sensor set-up configuration, on-line diagnostic and signal transmission are discussed.
Revised transport estimates of the Denmark Strait overflow
Jochumsen, Kerstin; Moritz, Martin; Nunes, Nuno; Quadfasel, Detlef; Larsen, Karin M. H.; Hansen, Bogi; Valdimarsson, Hedinn; Jonsson, Steingrimur
The major export route of dense water from the Nordic Seas into the North Atlantic is in the deep channel in Denmark Strait. Here currents have been monitored with one or two moored Acoustic Doppler Current Profilers (ADCPs) since 1996. Volume transport estimates of the Denmark Strait Overflow Water (DSOW) so far were based on these data, which were regressed to the total transport of dense water in a numerical model. The resulting transport has been used in many publications. Here we present results from an extended five-mooring array deployed in 2014/2015, which included measurements outside the swift overflow core. This array provided the basis for new calculations to estimate the DSOW transports. Furthermore, a correction is proposed for biases detected on some ADCPs, which led to earlier underestimation of the flow in the lower part of the plume. Using the new method, the mean DSOW transport is estimated to be 3.2 Sv in the period 1996-2016, without a significant trend. Uncertainties are typically ±0.5 Sv. Beyond variations on the eddy scale, an empirical orthogonal functions (EOF) analysis of the velocity field reveals three dominant modes of variability: the first mode is roughly barotropic and corresponds to pulsations of the plume, the second mode represents the laterally shifting component of the plume's core position, and the third mode indicates the impact of the varying overflow thickness. Finally, DSOW transports are compared to the Faroe Bank Channel overflow transports, but no clear relationship is found.
Efficient Heuristics for Simulating Population Overflow in Parallel Networks
Zaburnenko, T.S.; Nicola, V.F.
In this paper we propose a state-dependent importance sampling heuristic to estimate the probability of population overflow in networks of parallel queues. This heuristic approximates the "optimal��? state-dependent change of measure without the need for costly optimization involved in other
Overflow behavoir in queues with many long-tailed inputs
M.R.H. Mandjes (Michel); S.C. Borst (Sem)
textabstractWe consider a fluid queue fed by a superposition of $n$ homogeneous on-off sources with generally distributed on- and off-periods. We scale buffer space $B$ and link rate $C$ by $n$, such that we get $nb$ and $nc$, respectively. Then we let $n$ grow large. In this regime, the overflow
Sign language recognition with the Kinect sensor based on conditional random fields.
Yang, Hee-Deok
Sign language is a visual language used by deaf people. One difficulty of sign language recognition is that sign instances of vary in both motion and shape in three-dimensional (3D) space. In this research, we use 3D depth information from hand motions, generated from Microsoft's Kinect sensor and apply a hierarchical conditional random field (CRF) that recognizes hand signs from the hand motions. The proposed method uses a hierarchical CRF to detect candidate segments of signs using hand motions, and then a BoostMap embedding method to verify the hand shapes of the segmented signs. Experiments demonstrated that the proposed method could recognize signs from signed sentence data at a rate of 90.4%.
Sign Language Recognition with the Kinect Sensor Based on Conditional Random Fields
Directory of Open Access Journals (Sweden)
Hee-Deok Yang
Full Text Available Sign language is a visual language used by deaf people. One difficulty of sign language recognition is that sign instances of vary in both motion and shape in three-dimensional (3D space. In this research, we use 3D depth information from hand motions, generated from Microsoft's Kinect sensor and apply a hierarchical conditional random field (CRF that recognizes hand signs from the hand motions. The proposed method uses a hierarchical CRF to detect candidate segments of signs using hand motions, and then a BoostMap embedding method to verify the hand shapes of the segmented signs. Experiments demonstrated that the proposed method could recognize signs from signed sentence data at a rate of 90.4%.
Modeling nanoscale gas sensors under realistic conditions: Computational screening of metal-doped carbon nanotubes
DEFF Research Database (Denmark)
García Lastra, Juan Maria; Mowbray, Duncan; Thygesen, Kristian Sommer
We use computational screening to systematically investigate the use of transition-metal-doped carbon nanotubes for chemical-gas sensing. For a set of relevant target molecules (CO, NH3, and H2S) and the main components of air (N2, O2, and H2O), we calculate the binding energy and change in condu......We use computational screening to systematically investigate the use of transition-metal-doped carbon nanotubes for chemical-gas sensing. For a set of relevant target molecules (CO, NH3, and H2S) and the main components of air (N2, O2, and H2O), we calculate the binding energy and change...... the change in the nanotube resistance per doping site as a function of the target molecule concentration assuming charge transport in the diffusive regime. Our analysis points to Ni-doped nanotubes as candidates for CO sensors working under typical atmospheric conditions....
Robust Road Condition Detection System Using In-Vehicle Standard Sensors
Castillo Aguilar, Juan Jesús; Cabrera Carrillo, Juan Antonio; Guerra Fernández, Antonio Jesús; Carabias Acosta, Enrique
The appearance of active safety systems, such as Anti-lock Braking System, Traction Control System, Stability Control System, etc., represents a major evolution in road safety. In the automotive sector, the term vehicle active safety systems refers to those whose goal is to help avoid a crash or to reduce the risk of having an accident. These systems safeguard us, being in continuous evolution and incorporating new capabilities continuously. In order for these systems and vehicles to work adequately, they need to know some fundamental information: the road condition on which the vehicle is circulating. This early road detection is intended to allow vehicle control systems to act faster and more suitably, thus obtaining a substantial advantage. In this work, we try to detect the road condition the vehicle is being driven on, using the standard sensors installed in commercial vehicles. Vehicle models were programmed in on-board systems to perform real-time estimations of the forces of contact between the wheel and road and the speed of the vehicle. Subsequently, a fuzzy logic block is used to obtain an index representing the road condition. Finally, an artificial neural network was used to provide the optimal slip for each surface. Simulations and experiments verified the proposed method. PMID:26703605
Robust Road Condition Detection System Using In-Vehicle Standard Sensors
Directory of Open Access Journals (Sweden)
Juan Jesús Castillo Aguilar
Full Text Available The appearance of active safety systems, such as Anti-lock Braking System, Traction Control System, Stability Control System, etc., represents a major evolution in road safety. In the automotive sector, the term vehicle active safety systems refers to those whose goal is to help avoid a crash or to reduce the risk of having an accident. These systems safeguard us, being in continuous evolution and incorporating new capabilities continuously. In order for these systems and vehicles to work adequately, they need to know some fundamental information: the road condition on which the vehicle is circulating. This early road detection is intended to allow vehicle control systems to act faster and more suitably, thus obtaining a substantial advantage. In this work, we try to detect the road condition the vehicle is being driven on, using the standard sensors installed in commercial vehicles. Vehicle models were programmed in on-board systems to perform real-time estimations of the forces of contact between the wheel and road and the speed of the vehicle. Subsequently, a fuzzy logic block is used to obtain an index representing the road condition. Finally, an artificial neural network was used to provide the optimal slip for each surface. Simulations and experiments verified the proposed method.
Wind forcing of salinity anomalies in the Denmark Strait overflow
Directory of Open Access Journals (Sweden)
S. Hall
Full Text Available The overflow of dense water from the Nordic Seas to the North Atlantic through Denmark Strait is an important part of the global thermohaline circulation. The salinity of the overflow plume has been measured by an array of current meters across the continental slope off the coast of Angmagssalik, southeast Greenland since September 1998. During 2004 the salinity of the overflow plume changed dramatically; the entire width of the array (70 km freshened between January 2004 and July 2004, with a significant negative salinity anomaly of about 0.06 in May. The event in May represents a fresh anomaly of over 3 standard deviations from the mean since recording began in 1998. The OCCAM 1/12° Ocean General Circulation Model not only reproduces the 2004 freshening event (r=0.96, p<0.01, but also correlates well with salinity observations over a previous 6 year period (r=0.54, p<0.01, despite the inevitable limitations of a z-coordinate model in representing the mixing processes at and downstream of the Denmark Strait sill. Consequently the physical processes causing the 2004 anomaly and prior variability in salinity are investigated using the model output. Our results reject the hypotheses that the anomaly is caused by processes occurring between the overflow sill and the moorings, or by an increase in upstream net freshwater input. Instead, we show that the 2004 salinity anomaly is caused by an increase in volume flux of low salinity water, with a potential density greater than 27.60 kg m−3, flowing towards the Denmark Strait sill in the East Greenland Current. This is caused by an increase in southward wind stress upstream of the sill at around 75° N 20° W four and a half months earlier, and an associated strengthening of the East Greenland Current.
Separated Control and Data Stacks to Mitigate Buffer Overflow Exploits
Directory of Open Access Journals (Sweden)
Christopher Kugler
Full Text Available Despite the fact that protection mechanisms like StackGuard, ASLR and NX are widespread, the development on new defense strategies against stack-based buffer overflows has not yet come to an end. In this article, we present a novel compiler-level protection called SCADS: Separated Control and Data Stacks that protects return addresses and saved frame pointers on a separate stack, called the control stack. In common computer programs, a single user mode stack is used to store control information next to data buffers. By separating control information from the data stack, we can protect sensitive pointers of a program's control flow from being overwritten by buffer overflows. To substantiate the practicability of our approach, we provide SCADS as an open source patch for the LLVM compiler infrastructure. Focusing on Linux and FreeBSD running on the AMD64 architecture, we show compatibility, security and performance results. As we make control flow information simply unreachable for buffer overflows, many exploits are stopped at an early stage of progression with only negligible performance overhead.
Intense mixing of the Faroe Bank Channel overflow
Fer, Ilker; Voet, Gunnar; Seim, Knut S.; Rudels, Bert; Latarius, Katrin
The continuous, swift flow of cold water across the sill of the Faroe Bank Channel, the deepest passage from the Nordic Seas to the North Atlantic Ocean, forms a bottom-attached dense plume (overflow). The amount and distribution of entrainment and mixing that the overflow encounters during its descent influence the ventilation of the deep North Atlantic, however, remain poorly known due to lack of direct measurements. Using the first direct turbulence measurements, we describe the dynamic properties and mixing of the overflow plume as it descends toward the Iceland Basin. The vigorously turbulent plume is associated with intense mixing and enhanced turbulent dissipation near the bottom and at the plume-ambient interface, but with a quiescent core. Our measurements show a pronounced transverse circulation consistent with rotating plume dynamics, a strong lateral variability in entrainment velocity, and a vertical structure composed of order 100 m thick stratified interface and comparably thick well-mixed bottom boundary layer with significant transport and entrainment.
Overflow proteinuria as a manifestation of unrecognized polymyositis
Directory of Open Access Journals (Sweden)
Kim HH
Full Text Available Hyun Ho Kim,1 Jae Young Kim,1 Sung Jun Kim,1,2 Eun Su Park,3 Seok Joon Shin,1,2 Kwi Young Kang,1,4 Yeon Sik Hong,1,4 Hye Eun Yoon1,21Department of Internal Medicine, College of Medicine, The Catholic University of Korea, 2Division of Nephrology, Department of Internal Medicine, Incheon St Mary's Hospital, 3Department of Pathology, Incheon St Mary's Hospital, 4Division of Rheumatology, Department of Internal Medicine, Incheon St Mary's Hospital, Incheon, Republic of KoreaAbstract: Polymyositis is a rare and gradually progressive autoimmune disease of skeletal muscle. Two main types of renal involvement have been described: acute tubular necrosis related to rhabdomyolysis and glomerulonephritis. However, cases of overflow proteinuria related to polymyositis have rarely been reported. Herein, we report a case of a 41-year-old male who presented with edema of both lower extremities. Laboratory studies revealed elevated creatine phosphokinase level, hypoalbuminemia, and a moderate amount of proteinuria, although albuminuria was not dominant. Urine electrophoresis showed an abnormally restricted zone in the β-fraction, which suggested overflow proteinuria of non-glomerular origin. Despite intravenous hydration, his serum creatine phosphokinase level did not decrease and his symptoms did not improve. Electromyography showed myopathy, and muscle biopsy revealed findings consistent with polymyositis. After corticosteroid therapy, his creatine phosphokinase level and proteinuria decreased and his clinical symptoms improved. This case demonstrates an atypical presentation of polymyositis manifested by overflow proteinuria.Keywords: polymyositis, proteinuria, rhabdomyolysis
Numerical 3-D Modelling of Overflows
DEFF Research Database (Denmark)
Larsen, Torben; Nielsen, L.; Jensen, B.
The present study uses laboratory experiments to evaluate the reliability of two types of numerical models of sewers systems: - 1-dimensional model based on the extended Saint-Venant equation including the term for curvature of the water surface (the so-called Boussinesq approximation) - 2- and 3......-dimensional so-called Volume of Fluid Models (VOF-models) based on the full Navier-Stokes equations (named NS3 and developed by DHI Water & Environment) As a general conclusion, the two numerical models show excellent results when compared with measurements. However, considerable errors occur when...... inappropriate boundary conditions and grid resolutions are chosen. The paper describes the used physical and numerical models and summarises the results....
Stage–discharge relationship for a pipe overflow structure in both free and submerged flow
Directory of Open Access Journals (Sweden)
Gilles Isenmann
Full Text Available Many facilities for urban drainage systems are equipped with a pipe overflow structure that can often be treated as a circular broad-crested weir. Thus it is possible to evaluate the overflow discharge through this device by measuring the water levels in the upstream tank and at the outlet of the pipe. In the present study, computational fluid dynamics (CFD is used to determine a relationship between the discharge and the water levels upstream and downstream of the orifice for a range of diameters between 200 and 600 mm and a relative head up to 2. Over 50 numerical simulations are performed to take into account all the operating conditions of the system: free flow, submerged flow and pressurized flow. A regression is applied to the resulting data in order to obtain an orifice equation valid in both free-flow and submerged-flow regimes. Specific formulas, derived from Bernoulli's theorem, are also given for pressurized flows. The proposed methodology is applied to two examples.
Spatial and Temporal Distribution of Norovirus and E. coli in Sydney Rock Oysters Following a Sewage Overflow into an Estuary.
Brake, Felicity; Kiermeier, Andreas; Ross, Tom; Holds, Geoffrey; Landinez, Lina; McLeod, Catherine
This paper reports a study of norovirus (NoV) GII distribution and persistence in Sydney rock oysters (SRO) (Saccostrea glomerata) located in an estuary after a pump station sewage overflow. SRO were strategically placed at six sites spanning the length of the estuary from the pump station to the sea. The spatial and temporal distribution of NoV, hepatitis A virus (HAV) and Escherichia coli (E. coli) in oysters was mapped after the contamination event. NoV GI and GII, HAV and E. coli were quantified for up to 48 days in oysters placed at six sites ranging from 0.05 to 8.20 km from the sewage overflow. NoV GII was detected up to 5.29 km downstream and persisted in oysters for 42 days at the site closest to the overflow. NoV GII concentrations decreased significantly over time; a reduction rate of 8.5% per day was observed in oysters (p oysters over time, as observed in this study and other published research, collectively suggest that GII reduction rates from oysters may be broadly similar, regardless of environmental conditions, oyster species and genotype.
Sensor drift and predicted calibration intervals of handheld temperature and relative humidity meters under residential field-use conditions.
Johnston James D; Magnusson, Brianna M; Eggett, Dennis; Mumford, Kyle; Collingwood, Scott C; Bernhardt, Scott A
Handheld temperature and relative humidity (T/RH) meters are commonly used in residential indoor air surveys. Although popular, T/RH meters are prone to sensor drift and consequent loss of accuracy, and thus instrument manufacturers often recommend annual calibration and adjustment. Field-use conditions, however, have been shown to accelerate electronic sensor drift in outdoor applications, resulting in out-of-tolerance measurements in less than one year. In the study described in this article, sensor drift was evaluated under residential field use for 30 handheld T/RH meters to predict needed calibration intervals based on hierarchical linear modeling. Instruments were used in 43 home visits over a 93-day period and were calibrated (without adjustment) 49 times over the study period with a laboratory standard. Analysis of covariance showed significant drift among temperature sensors for all three instrument types (p humidity sensors in two instruments. The authors' study suggests calibration frequency should be based on instrument performance under specific sampling conditions rather than on predetermined time intervals.
Sensor Fish Characterization of Fish Passage Conditions through John Day Dam Spillbay 20 with a Modified Flow Deflector
Energy Technology Data Exchange (ETDEWEB)
Duncan, Joanne P.
Fish passage conditions over a modified deflector in Spillbay 20 at John Day Dam were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers (USACE), Portland District, using Sensor Fish devices. The objectives of the study were to describe and compare passage exposure conditions at two spill discharges, 2.4 and 4.0 thousand cubic feet per second (kcfs), identifying potential fish injury regions within the routes, and to evaluate a low-tailwater condition at the 2.4-kcfs discharge. The study was performed in April 2010 concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish data were analyzed to estimate 1) exposure conditions, particularly exposure to severe collision and shear events; 2) differences in passage conditions between treatments; and 3) relationships to live-fish injury and mortality data estimates. Nearly all Sensor Fish significant events were classified as collisions; the most severe occurred at the gate, on the spillbay chute, or at the deflector transition. Collisions in the gate region were observed only during the 2.4-kcfs discharge, when the tainter gate was open 1.2 ft. One shear event was observed during the evaluation, occurring at the deflector transition during passage at the 2.4-kcfs discharge at low tailwater. Flow quality, computed using the Sensor Fish turbulence index, was best for passage at the low-flow low-tailwater condition as well. The worst flow quality was observed for the 4.0-kcfs test condition. Contrasting the passage exposure conditions, the 2.4-kcfs low-tailwater treatment would be most deleterious to fish survival and well-being.
Correlations in Output and Overflow Traffic Processes in Simple Queues
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Don McNickle
Full Text Available We consider some simple Markov and Erlang queues with limited storage space. Although the departure processes from some such systems are known to be Poisson, they actually consist of the superposition of two complex correlated processes, the overflow process and the output process. We measure the cross-correlation between the counting processes for these two processes. It turns out that this can be positive, negative, or even zero (without implying independence. The models suggest some general principles on how big these correlations are, and when they are important. This may suggest when renewal or moment approximations to similar processes will be successful, and when they will not.
Low velocity impact monitoring of composite wing structure under simulated wing loading condition using fiber Bragg grating sensors
Shrestha, Pratik; Park, Yurim; Kwon, Hyunseok; Kim, Chun-Gon
A low velocity impact onto a composite structure can result in the occurrence of barely visible impact damage (BVID), which is difficult to detect. Therefore, the low velocity impact monitoring of composite structures is highly desirable for impact detection and localization. In this paper, low velocity impacts on a composite wing under a simulated wing loading condition were monitored using six multiplexed fiber Bragg grating (FBG) sensors and localized using error outlier based impact localization algorithm. The impact response signals from the FBG sensors were sampled at a rate of 100 kHz using high-speed interrogator. The impacts were localized with an average error of 18.4 mm.
New Electric Online Oil Condition Monitoring Sensor – an Innovation in Early Failure Detection of Industrial Gears
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Manfred Mauntz
Full Text Available A new online diagnostics system for the continuous condition monitoring of lubricating oils in industrial gearboxes is presented. Characteristic features of emerging component damage, such as wear, contamination or chemical aging, are identified in an early stage. The OilQSens® sensor effectively controls the proper operation conditions of bearings and cogwheels in gears. Also, the condition of insulating oils in transformers can be monitored. The online diagnostics system measures components of the specific complex impedance of oils. For instance, metal abrasion due to wear debris, broken oil molecules, forming acids or oil soaps result in an increase of the electrical conductivity, which directly correlates with the degree of contamination in the oil. The dielectrical properties of the oils are particularly determined by the water content that becomes accessible via an additional accurate measurement of the dielectric constant. For additivated oils, statements on the degradation of additives can also be derived from changes in the dielectric constant. For an efficient machine utilization and targeted damage prevention, the new OilQSens® online condition monitoring sensor system allows for timely preventative maintenance on demand rather than in rigid inspection intervals. The determination of impurities or reduction in the quality of the oil and the quasi continuous evaluation of wear and chemical aging follow the holistic approach of a real-time monitoring of a change in the condition of the oil-machine system. Once the oil condition monitoring sensors are installed on the plants, the measuring data can be displayed and evaluated elsewhere. The measuring signals are transmitted to a web-based condition monitoring system via LAN, WLAN or serial interfaces of the sensor system. Monitoring of the damage mechanisms during proper operation below the tolerance limits of the components enables specific preventive maintenance independent of rigid
Controlled overflowing of data-intensive jobs from oversubscribed sites
Sfiligoi, Igor; Bockelman, Brian Paul; Bradley, Daniel Charles; Tadel, Matevz; Bloom, Kenneth Arthur; Letts, James; Mrak Tadel, Alja
The CMS analysis computing model was always relying on jobs running near the data, with data allocation between CMS compute centers organized at management level, based on expected needs of the CMS community. While this model provided high CPU utilization during job run times, there were times when a large fraction of CPUs at certain sites were sitting idle due to lack of demand, all while Terabytes of data were never accessed. To improve the utilization of both CPU and disks, CMS is moving toward controlled overflowing of jobs from sites that have data but are oversubscribed to others with spare CPU and network capacity, with those jobs accessing the data through real time Xrootd streaming over WAN. The major limiting factor for remote data access is the ability of the source storage system to serve such data, so the number of jobs accessing it must be carefully controlled. The CMS approach to this is to implement the overflowing by means of glideinWMS, a Condor based pilot system, and by providing the WMS w...
Field tests of Fibre Bragg Grating sensors incorporated into CFRP for Railway Bridge strengthening condition monitoring
DEFF Research Database (Denmark)
Täljsten, Björn; Kerrouche, Abdelfathe; Leighton, J
project 'Sustainable Bridges'. The FBG sensors were embedded in Carbon Fibre Reinforced Polymers (CFRP) rods incorporated into grooves specially created in the concrete cover of the bridge structure and interrogated using a compact system based on Wavelength Division Multiplexing (WDM). Throughout......This paper reports results obtained from an unusual situation in structural monitoring – a 'test-to-destruction', measuring strain using a series of fibre Bragg gratings (FBG) sensors on a decommissioned concrete Railway Bridge in Örnsköldsvik, Sweden. The study formed part of the FP6 EU funded...... the study, the FBG sensors were continuously monitored, allowing the incremental increases in the strain to be seen and through the yield point of the carbon composite reinforcement. The sensors were able to follow the resulting induced changes in strain of over a range in excess of 4000µε. The measurements...
Fiber Optic Sensors for Leak Detection and Condition Monitoring in Hydrogen Fuel Systems Project
National Aeronautics and Space Administration — This SBIR Phase I proposal addresses the need for explosion proof, sensitive and reliable hydrogen sensors for NASA and commercial hydrogen fuel systems. It also...
Boundary Layer Separation and Reattachment Detection on Airfoils by Thermal Flow Sensors
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Peter Busche
Full Text Available A sensor concept for detection of boundary layer separation (flow separation, stall and reattachment on airfoils is introduced in this paper. Boundary layer separation and reattachment are phenomena of fluid mechanics showing characteristics of extinction and even inversion of the flow velocity on an overflowed surface. The flow sensor used in this work is able to measure the flow velocity in terms of direction and quantity at the sensor's position and expected to determine those specific flow conditions. Therefore, an array of thermal flow sensors has been integrated (flush-mounted on an airfoil and placed in a wind tunnel for measurement. Sensor signals have been recorded at different wind speeds and angles of attack for different positions on the airfoil. The sensors used here are based on the change of temperature distribution on a membrane (calorimetric principle. Thermopiles are used as temperature sensors in this approach offering a baseline free sensor signal, which is favorable for measurements at zero flow. Measurement results show clear separation points (zero flow and even negative flow values (back flow for all sensor positions. In addition to standard silicon-based flow sensors, a polymer-based flexible approach has been tested showing similar results.
High-Density Fiber Optical Sensor and Instrumentation for Gas Turbine Operation Condition Monitoring
Hua Xia; Doug Byrd; Sachin Dekate; Boon Lee
Gas turbine operation control is normally based on thermocouple-measured exhaust temperatures. Due to radiation shielding and bulky package, it is difficult to provide high spatial resolution for measuring can-to-can combustion temperature profile at the exhaust duct. This paper has demonstrated that wavelength-division-multiplexing-based fiber Bragg grating sensors could provide high spatial resolution steady and dynamic temperature measurements. A robust sensor package can be designed with ...
Technology in Strength and Conditioning: Assessing Bodyweight Squat Technique With Wearable Sensors.
O'Reilly, Martin A; Whelan, Darragh F; Ward, Tomas E; Delahunt, Eamonn; Caulfield, Brian M
O'Reilly, MA, Whelan, DF, Ward, TE, Delahunt, E, and Caulfield, BM. Technology in strength and conditioning: assessing bodyweight squat technique with wearable sensors. J Strength Cond Res 31(8): 2303-2312, 2017-Strength and conditioning (S&C) coaches offer expert guidance to help those they work with achieve their personal fitness goals. However, it is not always practical to operate under the direct supervision of an S&C coach and consequently individuals are often left training without expert oversight. Recent developments in inertial measurement units (IMUs) and mobile computing platforms have allowed for the possibility of unobtrusive motion tracking systems and the provision of real-time individualized feedback regarding exercise performance. These systems could enable S&C coaches to remotely monitor sessions and help individuals record their workout performance. One aspect of such technologies is the ability to assess exercise technique and detect common deviations from acceptable exercise form. In this study, we investigate this ability in the context of a bodyweight (BW) squat exercise. Inertial measurement units were positioned on the lumbar spine, thighs, and shanks of 77 healthy participants. Participants completed repetitions of BW squats with acceptable form and 5 common deviations from acceptable BW squatting technique. Descriptive features were extracted from the IMU signals for each BW squat repetition, and these were used to train a technique classifier. Acceptable or aberrant BW squat technique can be detected with 98% accuracy, 96% sensitivity, and 99% specificity when using features derived from all 5 IMUs. A single IMU system can also distinguish between acceptable and aberrant BW squat biomechanics with excellent accuracy, sensitivity, and specificity. Detecting exact deviations from acceptable BW squatting technique can be achieved with 80% accuracy using a 5 IMU system and 72% accuracy when using a single IMU positioned on the right shank
Investigating the role of the corpus callosum in regulating motor overflow in multiple sclerosis.
Ternes, Anne-Marie; Maller, Jerome J; Fielding, Joanne; Addamo, Patricia; White, Owen; Georgiou-Karistianis, Nellie
The corpus callosum (CC) is commonly affected in multiple sclerosis (MS), however, sensitive behavioral measures of MS-related CC pathology are lacking. The CC is considered a key structure in the mediation of a type of involuntary movement known as motor overflow. In this study, we sought to characterize the impact of CC damage on motor overflow in MS. Twenty MS participants and 20 controls performed a unilateral force production task. Motor overflow (involuntary force) in the non-active hand was measured while the active hand performed the task. CC volume and lesion load were calculated for MS participants using T2-weighted MRI. We found no group differences in motor overflow; however, motor overflow correlated significantly with MS disease severity [Expanded disability status scale (EDSS)]. CC damage (lesions and decreased volume) did not correlate with motor overflow. This study suggests that CC damage may not directly lead to changes in the regulation of motor overflow. Rather, findings support the notion that a wider network of structures may mediate the production and suppression of motor overflow.
Performance and Application of Parallel OVERFLOW Codes on Distributed and Shared Memory Platforms
Djomehri, M. Jahed; Rizk, Yehia M.
The presentation discusses recent studies on the performance of the two parallel versions of the aerodynamics CFD code, OVERFLOW_MPI and _MLP. Developed at NASA Ames, the serial version, OVERFLOW, is a multidimensional Navier-Stokes flow solver based on overset (Chimera) grid technology. The code has recently been parallelized in two ways. One is based on the explicit message-passing interface (MPI) across processors and uses the _MPI communication package. This approach is primarily suited for distributed memory systems and workstation clusters. The second, termed the multi-level parallel (MLP) method, is simple and uses shared memory for all communications. The _MLP code is suitable on distributed-shared memory systems. For both methods, the message passing takes place across the processors or processes at the advancement of each time step. This procedure is, in effect, the Chimera boundary conditions update, which is done in an explicit "Jacobi" style. In contrast, the update in the serial code is done in more of the "Gauss-Sidel" fashion. The programming efforts for the _MPI code is more complicated than for the _MLP code; the former requires modification of the outer and some inner shells of the serial code, whereas the latter focuses only on the outer shell of the code. The _MPI version offers a great deal of flexibility in distributing grid zones across a specified number of processors in order to achieve load balancing. The approach is capable of partitioning zones across multiple processors or sending each zone and/or cluster of several zones into a single processor. The message passing across the processors consists of Chimera boundary and/or an overlap of "halo" boundary points for each partitioned zone. The MLP version is a new coarse-grain parallel concept at the zonal and intra-zonal levels. A grouping strategy is used to distribute zones into several groups forming sub-processes which will run in parallel. The total volume of grid points in each
Observing mixing in the Faroe Bank Channel overflow with gliders
Ullgren, Jenny; Fer, Ilker; Darelius, Elin; Peterson, Algot
Cold, dense water from the Nordic Seas flows out into the North Atlantic across the Iceland-Scotland Ridge underneath the warmer Atlantic water. About a third of the overflow volume passes through the Faroe Bank Channel (FBC), a narrow passage with a sill depth of 840 m. The current velocity in the Channel is high (on the order of 1 m/s), and the highly variable flow is dominated by oscillations with a period of 2-3 days. In order to study the mixing and entrainment of the overflow in detail and at a time scale resolving the mesoscale oscillations, a field campaign was undertaken in 2012. Apart from repeat sections with CTD-LADCP and Vertical Microstructure Profiler (VMP), two Slocum electric gliders were deployed, one of them equipped with a MicroRider turbulence package. A total of 104 dives that reached into the plume (with bottom temperatures ≤3°C) were completed, 69 of which with the MicroRider glider. The in situ observations from May-June 2012 show that the mesoscale variability strongly influences the overflow plume in terms of hydrographic structure, transport, and turbulence. CTD data from the two gliders complemented the shipboard survey and highlighted the temporally and spatially varying distribution of intermediate water which sometimes is found between the light Atlantic water and the dense waters originating in the Nordic Seas. The presence or absence of intermediate water and the various degrees to which its signal is removed by the vigorous mixing in the plume and at the turbulent interface complicates the view of this system, but can also help shed light on the circulation and the mixing in the Channel. Profiles of turbulent dissipation rate inferred from the turbulence measuring glider and the VMP on average agree very well above about 300 m above the seabed, but the glider-derived dissipation rates are systematically about a factor of two larger inside the plume and interface. The good agreement in the upper part of the water column shows
Long-term variations in Iceland–Scotland overflow strength during the Holocene
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D. J. R. Thornalley
Full Text Available The overflow of deep water from the Nordic seas into the North Atlantic plays a critical role in global ocean circulation and climate. Approximately half of this overflow occurs via the Iceland–Scotland (I–S overflow, yet the history of its strength throughout the Holocene (~ 0–11 700 yr ago, ka is poorly constrained, with previous studies presenting apparently contradictory evidence regarding its long-term variability. Here, we provide a comprehensive reconstruction of I–S overflow strength throughout the Holocene using sediment grain size data from a depth transect of 13 cores from the Iceland Basin. Our data are consistent with the hypothesis that the main axis of the I–S overflow on the Iceland slope was shallower during the early Holocene, deepening to its present depth by ~ 7 ka. Our results also reveal weaker I–S overflow during the early and late Holocene, with maximum overflow strength occurring at ~ 7 ka, the time of a regional climate thermal maximum. Climate model simulations suggest a shoaling of deep convection in the Nordic seas during the early and late Holocene, consistent with our evidence for weaker I–S overflow during these intervals. Whereas the reduction in I–S overflow strength during the early Holocene likely resulted from melting remnant glacial ice sheets, the decline throughout the last 7000 yr was caused by an orbitally induced increase in the amount of Arctic sea ice entering the Nordic seas. Although the flux of Arctic sea ice to the Nordic seas is expected to decrease throughout the next century, model simulations predict that under high emissions scenarios, competing effects, such as warmer sea surface temperatures in the Nordic seas, will result in reduced deep convection, likely driving a weaker I–S overflow.
A new on-line luminometer and beam conditions monitor using single crystal diamond sensors
CMS Collaboration
Instrumentation near the beam-pipe requires extremely radiation hard sensors. Inside CMS two rings instrumented with 12 single crystal diamond sensors each are installed on both sides of the interaction point. The sensors are subdivided in two pads, and each pad is read out by a dedicated fast radiation hard ASIC in 130 nm CMOS technology. Due to the excellent time resolution collision products will be separated from machine induced background. In the backend a dead-time less histogramming unit is used, and a fast microTCA system with GHz sampling rate is under development. The detector will measure both the on-line luminosity and the background bunch-by-bunch. The performance of a prototype detector in a test-beam will be reported, and results from the operation during data taking will be presented.
Influence of cabin conditions on placement and response of contaminant detection sensors in a commercial aircraft.
Mazumdar, Sagnik; Chen, Qingyan
Potential causalities due to airborne disease transmission and risk of chem-bio terrorism in commercial airliner cabins can be reduced by fast responses. Fast responses are only possible by using sensors at appropriate locations in the cabins. Cost, size and weight factors restrict the number of sensors that could be installed inside a cabin. Since release locations and seating patterns of passengers can impact airborne contaminant transports, this study first addressed this impact by using a validated computational fluid dynamics (CFD) program in a four-row mockup of twin-aisle airliner cabin. It was observed that occupancy patterns and release locations have little influence on longitudinal contaminant transports though localized variations of contaminant concentrations may exist. The results show that response time of the sensors is considerably reduced with the increase in number of sensors. If only a single sensor is available across a cabin cross-section then it should be placed at the middle of the ceiling. A cabin model of a fully occupied twin-aisle airliner with 210 seats was also build to study the diverse contaminant distribution trends along cabin length. The results reveal that seating arrangements can make cross-sectional airflow pattern considerably asymmetrical. Similar airflow patterns make the longitudinal contaminant transport in the business and economy classes alike. The presence of galleys greatly affected the longitudinal transport of contaminants in a particular cabin section. The effects due to galleys were less significant if a multipoint sampling system was used. The multipoint sampling system can also reduce the number of sensors required in a cabin.
Development of an environmental chamber for evaluating the performance of low-cost air quality sensors under controlled conditions
Papapostolou, Vasileios; Zhang, Hang; Feenstra, Brandon J.; Polidori, Andrea
A state-of-the-art integrated chamber system has been developed for evaluating the performance of low-cost air quality sensors. The system contains two professional grade chamber enclosures. A 1.3 m3 stainless-steel outer chamber and a 0.11 m3 Teflon-coated stainless-steel inner chamber are used to create controlled aerosol and gaseous atmospheres, respectively. Both chambers are temperature and relative humidity controlled with capability to generate a wide range of environmental conditions. The system is equipped with an integrated zero-air system, an ozone and two aerosol generation systems, a dynamic dilution calibrator, certified gas cylinders, an array of Federal Reference Method (FRM), Federal Equivalent Method (FEM), and Best Available Technology (BAT) reference instruments and an automated control and sequencing software. Our experiments have demonstrated that the chamber system is capable of generating stable and reproducible aerosol and gas concentrations at low, medium, and high levels. This paper discusses the development of the chamber system along with the methods used to quantitatively evaluate sensor performance. Considering that a significant number of academic and research institutions, government agencies, public and private institutions, and individuals are becoming interested in developing and using low-cost air quality sensors, it is important to standardize the procedures used to evaluate their performance. The information discussed herein provides a roadmap for entities who are interested in characterizing air quality sensors in a rigorous, systematic and reproducible manner.
Atmospheric forcing of salinity in the overflow of Denmark Strait
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J. Holfort
Full Text Available The temporal evolution of the characteristics of Denmark Strait Overflow Water (DSOW is reconstructed using hydrographic data and compared with possible atmospheric forcing mechanisms. It is concluded that the main factor influencing the DSOW characteristics at a time scale of one to several years is the difference in mean sea level pressure across Denmark Strait or, in other words, the wind along Denmark Strait. At these time scales upstream changes in the characteristics of the different water masses involved in the formation of DSOW are only of minor importance. The main process responsible for the observed salinity changes in the DSOW is mixing in Denmark Strait. Triggered by the wind, different water masses contribute with changing amounts to the formation of DSOW, leading to the observed changes in the salinity of DSOW.
Performance Modeling for Heterogeneous Wireless Networks with Multiservice Overflow Traffic
DEFF Research Database (Denmark)
Huang, Qian; Ko, King-Tim; Iversen, Villy Bæk
Performance modeling is important for the purpose of developing efficient dimensioning tools for large complicated networks. But it is difficult to achieve in heterogeneous wireless networks, where different networks have different statistical characteristics in service and traffic models....... Multiservice loss analysis based on multi-dimensional Markov chain becomes intractable in these networks due to intensive computations required. This paper focuses on performance modeling for heterogeneous wireless networks based on a hierarchical overlay infrastructure. A method based on decomposition...... of the correlated traffic is used to achieve an approximate performance modeling for multiservice in hierarchical heterogeneous wireless networks with overflow traffic. The accuracy of the approximate performance obtained by our proposed modeling is verified by simulations....
Understanding the interplay of carbon and nitrogen supply for ectoines production and metabolic overflow in high density cultures of Chromohalobacter salexigens.
Salar-García, María J; Bernal, Vicente; Pastor, José M; Salvador, Manuel; Argandoña, Montserrat; Nieto, Joaquín J; Vargas, Carmen; Cánovas, Manuel
The halophilic bacterium Chromohalobacter salexigens has been proposed as promising cell factory for the production of the compatible solutes ectoine and hydroxyectoine. This bacterium has evolved metabolic adaptations to efficiently grow under high salt concentrations by accumulating ectoines as compatible solutes. However, metabolic overflow, which is a major drawback for the efficient conversion of biological feedstocks, occurs as a result of metabolic unbalances during growth and ectoines production. Optimal production of ectoines is conditioned by the interplay of carbon and nitrogen metabolisms. In this work, we set out to determine how nitrogen supply affects the production of ectoines. Chromohalobacter salexigens was challenged to grow in media with unbalanced carbon/nitrogen ratio. In C. salexigens, overflow metabolism and ectoines production are a function of medium composition. At low ammonium conditions, the growth rate decreased importantly, up to 80%. Shifts in overflow metabolism were observed when changing the C/N ratio in the culture medium. 13C-NMR analysis of ectoines labelling revealed a high metabolic rigidity, with almost constant flux ratios in all conditions assayed. Unbalanced C/N ratio led to pyruvate accumulation, especially upon N-limitation. Analysis of an ect - mutant demonstrated the link between metabolic overflow and ectoine biosynthesis. Under non ectoine synthesizing conditions, glucose uptake and metabolic overflow decreased importantly. Finally, in fed-batch cultures, biomass yield was affected by the feeding scheme chosen. High growth (up to 42.4 g L-1) and volumetric ectoine yields (up to 4.21 g L-1) were obtained by minimizing metabolite overflow and nutrient accumulation in high density cultures in a low nitrogen fed-batch culture. Moreover, the yield coefficient calculated for the transformation of glucose into biomass was 30% higher in fed-batch than in the batch culture, demonstrating that the metabolic efficiency of
Aquatic Nitrate Retention at River Network Scales Across Flow Conditions Determined Using Nested In Situ Sensors
Wollheim, W. M.; Mulukutla, G. K.; Cook, C.; Carey, R. O.
Nonpoint pollution sources are strongly influenced by hydrology and are therefore sensitive to climate variability. Some pollutants entering aquatic ecosystems, e.g., nitrate, can be mitigated by in-stream processes during transport through river networks. Whole river network nitrate retention is difficult to quantify with observations. High frequency, in situ nitrate sensors, deployed in nested locations within a single watershed, can improve estimates of both nonpoint inputs and aquatic retention at river network scales. We deployed a nested sensor network and associated sampling in the urbanizing Oyster River watershed in coastal New Hampshire, USA, to quantify storm event-scale loading and retention at network scales. An end member analysis used the relative behavior of reactive nitrate and conservative chloride to infer river network fate of nitrate. In the headwater catchments, nitrate and chloride concentrations are both increasingly diluted with increasing storm size. At the mouth of the watershed, chloride is also diluted, but nitrate tended to increase. The end member analysis suggests that this pattern is the result of high retention during small storms (51-78%) that declines to zero during large storms. Although high frequency nitrate sensors did not alter estimates of fluxes over seasonal time periods compared to less frequent grab sampling, they provide the ability to estimate nitrate flux versus storm size at event scales that is critical for such analyses. Nested sensor networks can improve understanding of the controls of both loading and network scale retention, and therefore also improve management of nonpoint source pollution.
Low Temperature CVD Grown Graphene for Highly Selective Gas Sensors Working under Ambient Conditions
Ricciardella, F.; Vollebregt, S.; Polichetti, T.; Alfano, B.; Massera, E.; Sarro, P.M.
In this paper we report on gas sensors based on graphene grown by Chemical Vapor Deposition at 850 °C. Mo was used as catalyst for graphene nucleation. Resistors were directly designed on pre-patterned Mo using the transfer-free process we recently developed, thus avoiding films damage during the
Toward daily monitoring of vegetation conditions at field scale through fusing data from multiple sensors
Vegetation monitoring requires remote sensing data at fine spatial and temporal resolution. While imagery from coarse resolution sensors such as MODIS/VIIRS can provide daily observations, they lack spatial detail to capture surface features for crop and rangeland monitoring. The Landsat satellite s...
Reliably measuring the condition of mineral-based transfer fluids using a permittivity sensor – practical application to thermal fluid heat transfer
Directory of Open Access Journals (Sweden)
Christopher Ian Wright
Full Text Available This article describes a series of experiments to assess the performance and suitability of a permittivity sensor in the area of heat transfer. The permittivity sensor measures condition index and temperature of a fluid. A series of 5 experiments was conducted. They assessed the reproducibility of the sensor using both clean and dirty fluid samples, and showed the sensor had good reproducibility based on calculations of coefficients of variation. The sensor also detected water contamination, assessed from construction of a stimulus-response curve to step-wise increases in water and from real-life samples where water content was reported to be out of specification. Further experiments tested the association between condition index and both water content and fluid cleanliness in a real-life setting. Results demonstrated the sensor that condition index reflected changes in fluid water and cleanliness and was therefore a measure of fluid condition. The implication of these findings is that the sensor can be used to make rapid and reliable assessments of fluid condition using only small samples (i.e., <50 ml. The sensor may be of benefit to customers that need to make a lot of regular samples over a large processing site, such as concentrated solar power plants.
Role of the α-adrenoceptor in regulating noradrenaline overflow by nerve stimulation
Enero, María A; Langer, S Z; Rothlin, R P; Stefano, F J E
A study of the actions of phenoxybenzamine on transmitter overflow, neuronal and extraneuronal uptake of noradrenaline and in causing α-adrenoceptor blockade was carried out using the isolated cat nictitating membrane preparation. Phenoxybenzamine increased transmitter overflow elicited by nerve-stimulation at 10 Hz in a concentration dependent manner in the range 10−8 to 10−5 g/ml. Neuronal uptake of [3H]-noradrenaline was not inhibited by concentrations lower than 10−6 g/ml of phenoxybenzamine. With 10−7 g/ml of phenoxybenzamine a significant increase in transmitter overflow was obtained, although neuronal uptake of noradrenaline was not affected. Higher concentrations of phenoxybenzamine (10−6 and 10−5 g/ml) inhibited the neuronal uptake of noradrenaline and further increased transmitter overflow. Extraneuronal uptake of [3H]-noradrenaline was inhibited only with the highest concentration of phenoxybenzamine tested (10−5 g/ml) and therefore appears to be unrelated to the effects on transmitter overflow. There was a significant correlation between the degree of α-adrenoceptor block produced by phenoxybenzamine and the increase in transmitter overflow obtained by nerve stimulation. These results indicate that phenoxybenzamine, in addition to increasing overflow by preventing reuptake of noradrenaline, may increase transmitter release. The possibility that phenoxybenzamine acts on α-adrenoceptors in the adrenergic nerve terminal is discussed. These receptors would be involved in a negative feedback mechanism regulating transmitter release. PMID:9142415
Characteristics of the overflow pollution of storm drains with inappropriate sewage entry.
Yin, Hailong; Lu, Yi; Xu, Zuxin; Li, Huaizheng; Schwegler, Benedict R
To probe the overflow pollution of separate storm drains with inappropriate sewage entries, in terms of the relationship between sewage entries and the corresponding dry-weather and wet-weather overflow, the monitoring activities were conducted in a storm drainage system in the Shanghai downtown area (374 ha). In this study site, samples from inappropriately entered dry-weather sewage and the overflow due to storm pumps operation on dry-weather and wet-weather days were collected and then monitored for six water quality constituents. It was found that overflow concentrations of dry-weather period could be higher than those of wet-weather period; under wet-weather period, the overflow concentrations of storm drains were close to or even higher than that of combined sewers. Relatively strong first flush mostly occurred under heavy rain that satisfied critical rainfall amount, maximum rainfall intensity, and maximum pumping discharge, while almost no first flush effect or only weak first flush effect was found for the other rainfall events. Such phenomenon was attributed to lower in-line pipe storage as compared to that of the combined sewers, and serious sediment accumulation within the storm pipes due to sewage entry. For this kind of system, treating a continuous overflow rate is a better strategy than treating the maximum amount of early part of the overflow. Correcting the key inappropriate sewage entries into storm drains should also be focused.
A neuromorphic model of motor overflow in focal hand dystonia due to correlated sensory input
Sohn, Won Joon; Niu, Chuanxin M.; Sanger, Terence D.
Objective. Motor overflow is a common and frustrating symptom of dystonia, manifested as unintentional muscle contraction that occurs during an intended voluntary movement. Although it is suspected that motor overflow is due to cortical disorganization in some types of dystonia (e.g. focal hand dystonia), it remains elusive which mechanisms could initiate and, more importantly, perpetuate motor overflow. We hypothesize that distinct motor elements have low risk of motor overflow if their sensory inputs remain statistically independent. But when provided with correlated sensory inputs, pre-existing crosstalk among sensory projections will grow under spike-timing-dependent-plasticity (STDP) and eventually produce irreversible motor overflow. Approach. We emulated a simplified neuromuscular system comprising two anatomically distinct digital muscles innervated by two layers of spiking neurons with STDP. The synaptic connections between layers included crosstalk connections. The input neurons received either independent or correlated sensory drive during 4 days of continuous excitation. The emulation is critically enabled and accelerated by our neuromorphic hardware created in previous work. Main results. When driven by correlated sensory inputs, the crosstalk synapses gained weight and produced prominent motor overflow; the growth of crosstalk synapses resulted in enlarged sensory representation reflecting cortical reorganization. The overflow failed to recede when the inputs resumed their original uncorrelated statistics. In the control group, no motor overflow was observed. Significance. Although our model is a highly simplified and limited representation of the human sensorimotor system, it allows us to explain how correlated sensory input to anatomically distinct muscles is by itself sufficient to cause persistent and irreversible motor overflow. Further studies are needed to locate the source of correlation in sensory input.
Signal Conditioning for the Kalman Filter: Application to Satellite Attitude Estimation with Magnetometer and Sun Sensors
Directory of Open Access Journals (Sweden)
Segundo Esteban
Full Text Available Most satellites use an on-board attitude estimation system, based on available sensors. In the case of low-cost satellites, which are of increasing interest, it is usual to use magnetometers and Sun sensors. A Kalman filter is commonly recommended for the estimation, to simultaneously exploit the information from sensors and from a mathematical model of the satellite motion. It would be also convenient to adhere to a quaternion representation. This article focuses on some problems linked to this context. The state of the system should be represented in observable form. Singularities due to alignment of measured vectors cause estimation problems. Accommodation of the Kalman filter originates convergence difficulties. The article includes a new proposal that solves these problems, not needing changes in the Kalman filter algorithm. In addition, the article includes assessment of different errors, initialization values for the Kalman filter; and considers the influence of the magnetic dipole moment perturbation, showing how to handle it as part of the Kalman filter framework.
Signal Conditioning for the Kalman Filter: Application to Satellite Attitude Estimation with Magnetometer and Sun Sensors.
Esteban, Segundo; Girón-Sierra, Jose M; Polo, Óscar R; Angulo, Manuel
Most satellites use an on-board attitude estimation system, based on available sensors. In the case of low-cost satellites, which are of increasing interest, it is usual to use magnetometers and Sun sensors. A Kalman filter is commonly recommended for the estimation, to simultaneously exploit the information from sensors and from a mathematical model of the satellite motion. It would be also convenient to adhere to a quaternion representation. This article focuses on some problems linked to this context. The state of the system should be represented in observable form. Singularities due to alignment of measured vectors cause estimation problems. Accommodation of the Kalman filter originates convergence difficulties. The article includes a new proposal that solves these problems, not needing changes in the Kalman filter algorithm. In addition, the article includes assessment of different errors, initialization values for the Kalman filter; and considers the influence of the magnetic dipole moment perturbation, showing how to handle it as part of the Kalman filter framework.
Quantitative and qualitative assessment of the impact of climate change on a combined sewer overflow and its receiving water body.
Bi, Eustache Gooré; Monette, Frédéric; Gachon, Philippe; Gaspéri, Johnny; Perrodin, Yves
Projections from the Canadian Regional Climate Model (CRCM) for the southern part of the province of Québec, Canada, suggest an increase in extreme precipitation events for the 2050 horizon (2041-2070). The main goal of this study consisted in a quantitative and qualitative assessment of the impact of the 20 % increase in rainfall intensity that led, in the summer of 2013, to overflows in the "Rolland-Therrien" combined sewer system in the city of Longueuil, Canada. The PCSWMM 2013 model was used to assess the sensitivity of this overflow under current (2013) and future (2050) climate conditions. The simulated quantitative variables (peak flow, Q(CSO), and volume discharged, VD) served as the basis for deriving ecotoxicological risk indices and event fluxes (EFs) transported to the St. Lawrence (SL) River. Results highlighted 15 to 500% increases in VD and 13 to 148% increases in Q(CSO) by 2050 (compared to 2013), based on eight rainfall events measured from May to October. These results show that (i) the relationships between precipitation and combined sewer overflow variables are not linear and (ii) the design criteria for current hydraulic infrastructure must be revised to account for the impact of climate change (CC) arising from changes in precipitation regimes. EFs discharged into the SL River will be 2.24 times larger in the future than they are now (2013) due to large VDs resulting from CC. This will, in turn, lead to excessive inputs of total suspended solids (TSSs) and tracers for numerous urban pollutants (organic matter and nutrients, metals) into the receiving water body. Ecotoxicological risk indices will increase by more than 100% by 2050 compared to 2013. Given that substantial VDs are at play, and although CC scenarios have many sources of uncertainty, strategies to adapt this drainage network to the effects of CC will have to be developed.
Unstable Roche-Lobe Overflow of Gaseous Planets
Jackson, Brian
The discoveries of more than 100 roughly Earth-sized bodies with orbital periods less than 1 day, ultra-short-period planets or candidates (USPs), have challenged planet formation theories, and evidence suggests USPs may be the remnants of gaseous planets that shed their atmospheres. Indeed, many hot Jupiters are near Roche-Lobe overflow (RLO), and tidal decay can push them the rest of the way in. Recent work has shown stable RLO (atmospheres lost via a steady outflow and thin accretion disk) probably cannot produce USPs on its own but suggested unstable RLO (atmospheres quickly shed on dynamical timescales) may. In fact, stable RLO may drive overflowing hot Jupiters into unstable RLO, and by analogy with the common-envelope binaries, the core that remains can drive off the gaseous envelope at the cost of its orbital energy. Wellestablished mass-radius relations for gaseous planets, coupled to simple energy and angular momentum considerations, provide a connection between the observed masses and periods for USPs and their putative progenitor gaseous planets, with few free parameters. We propose to investigate the hypothesis that USPs originate through tidal decay and a combination of stable and unstable Roche-lobe overflow of short-period gaseous planets through the following studies: -We will explore the planetary masses, orbital periods, etc. that produce unstable RLO using the Modules for Experiments in Stellar Astrophysics (MESA) suite. -We will relate the observed periods and masses of USPs to their putative progenitor masses and periods to see whether they are consistent with the unstable RLO hypothesis. This proposal is directly relevant to the Exoplanets Research Program since it seeks to "understand the ... physical processes of exoplanets" and "improve understanding of [their] origins" through "theoretical studies ... and modeling'". We also expect that it will have broad impacts on a variety of astrophysical topics: -Ultra-short period planets could
Comparison of the high temperature heat flux sensor to traditional heat flux gages under high heat flux conditions.
Energy Technology Data Exchange (ETDEWEB)
Blanchat, Thomas K.; Hanks, Charles R.
Four types of heat flux gages (Gardon, Schmidt-Boelter, Directional Flame Temperature, and High Temperature Heat Flux Sensor) were assessed and compared under flux conditions ranging between 100-1000 kW/m2, such as those seen in hydrocarbon fire or propellant fire conditions. Short duration step and pulse boundary conditions were imposed using a six-panel cylindrical array of high-temperature tungsten lamps. Overall, agreement between all gages was acceptable for the pulse tests and also for the step tests. However, repeated tests with the HTHFS with relatively long durations at temperatures approaching 1000ÀC showed a substantial decrease (10-25%) in heat flux subsequent to the initial test, likely due to the mounting technique. New HTHFS gages have been ordered to allow additional tests to determine the cause of the flux reduction.
3D Imaging with a Sonar Sensor and an Automated 3-Axes Frame for Selective Spraying in Controlled Conditions
Directory of Open Access Journals (Sweden)
David Reiser
Full Text Available Autonomous selective spraying could be a way for agriculture to reduce production costs, save resources, protect the environment and help to fulfill specific pesticide regulations. The objective of this paper was to investigate the use of a low-cost sonar sensor for autonomous selective spraying of single plants. For this, a belt driven autonomous robot was used with an attached 3-axes frame with three degrees of freedom. In the tool center point (TCP of the 3-axes frame, a sonar sensor and a spray valve were attached to create a point cloud representation of the surface, detect plants in the area and perform selective spraying. The autonomous robot was tested on replicates of artificial crop plants. The location of each plant was identified out of the acquired point cloud with the help of Euclidian clustering. The gained plant positions were spatially transformed from the coordinates of the sonar sensor to the valve location to determine the exact irrigation points. The results showed that the robot was able to automatically detect the position of each plant with an accuracy of 2.7 cm and could spray on these selected points. This selective spraying reduced the used liquid by 72%, when comparing it to a conventional spraying method in the same conditions.
Level II contaminant investigation of Overflow National Wildlife Refuge, Wilmot, Arkansas
US Fish and Wildlife Service, Department of the Interior — Conductivity and turbidity exhibited the greatest variation of the water quality parameters measured at Overflow NWR and the proposed acquisition land (Table 2)....
Mobile Acoustical Bat Monitoring Annual Summary Report CY 2016- Overflow National Wildlife Refuge
US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Overflow National Wildlife Refuge for the CY 2016. Calls were classified using Bat Call ID software...
Mobile Acoustical Bat Monitoring Annual Summary Report CY 2014- Overflow National Wildlife Refuge
US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Overflow National Wildlife Refuge for the CY 2014. Calls were classified using Bat Call ID software...
Design and Application of a High Sensitivity Piezoresistive Pressure Sensor for Low Pressure Conditions
Directory of Open Access Journals (Sweden)
Huiyang Yu
Full Text Available In this paper, a pressure sensor for low pressure detection (0.5 kPa–40 kPa is proposed. In one structure (No. 1, the silicon membrane is partly etched to form a crossed beam on its top for stress concentration. An aluminum layer is also deposited as part of the beam. Four piezoresistors are fabricated. Two are located at the two ends of the beam. The other two are located at the membrane periphery. Four piezoresistors connect into a Wheatstone bridge. To demonstrate the stress concentrate effect of this structure, two other structures were designed and fabricated. One is a flat membrane structure (No. 2, the other is a structure with the aluminum beam, but without etched silicon (No. 3. The measurement results of these three structures show that the No.1 structure has the highest sensitivity, which is about 3.8 times that of the No. 2 structure and 2.7 times that of the No. 3 structure. They also show that the residual stress in the beam has some backside effect on the sensor performance.
Design and Application of a High Sensitivity Piezoresistive Pressure Sensor for Low Pressure Conditions.
Yu, Huiyang; Huang, Jianqiu
In this paper, a pressure sensor for low pressure detection (0.5 kPa-40 kPa) is proposed. In one structure (No. 1), the silicon membrane is partly etched to form a crossed beam on its top for stress concentration. An aluminum layer is also deposited as part of the beam. Four piezoresistors are fabricated. Two are located at the two ends of the beam. The other two are located at the membrane periphery. Four piezoresistors connect into a Wheatstone bridge. To demonstrate the stress concentrate effect of this structure, two other structures were designed and fabricated. One is a flat membrane structure (No. 2), the other is a structure with the aluminum beam, but without etched silicon (No. 3). The measurement results of these three structures show that the No.1 structure has the highest sensitivity, which is about 3.8 times that of the No. 2 structure and 2.7 times that of the No. 3 structure. They also show that the residual stress in the beam has some backside effect on the sensor performance.
Minimized Bolus-Type Wireless Sensor Node with a Built-In Three-Axis Acceleration Meter for Monitoring a Cow's Rumen Conditions
Directory of Open Access Journals (Sweden)
Hirofumi Nogami
Full Text Available Monitoring rumen conditions in cows is important because a dysfunctional rumen system may cause death. Sub-acute ruminal acidosis (SARA is a typical disease in cows, and is characterized by repeated periods of low ruminal pH. SARA is regarded as a trigger for rumen atony, rumenitis, and abomasal displacement, which may cause death. In previous studies, rumen conditions were evaluated by wireless sensor nodes with pH measurement capability. The primary advantage of the pH sensor is its ability to continuously measure ruminal pH. However, these sensor nodes have short lifetimes since they are limited by the finite volume of the internal liquid of the reference electrode. Mimicking rumen atony, we attempt to evaluate the rumen condition using wireless sensor nodes with three-axis accelerometers. The theoretical life span of such sensor nodes depends mainly on the transmission frequency of acceleration data and the size of the battery, and the proposed sensor nodes are 30.0 mm in diameter and 70.0 mm in length and have a life span of over 600 days. Using the sensor nodes, we compare the rumen motility of the force transducer measurement with the three-axis accelerometer data. As a result, we can detect discriminative movement of rumen atony.
Optimizing sensitivity of Unmanned Aerial System optical sensors for low zenith angles and cloudy conditions
DEFF Research Database (Denmark)
Wang, Sheng; Dam-Hansen, Carsten; Zarco Tejada, Pablo J.
or carbon assimilation are biased towards clear sky conditions, lacking important information on biophysical processes under cloudy conditions. Unmanned Aerial Vehicle (UAV) imagery has great potential to monitor and understand surface fluxes under cloudy conditions. For instance, in Denmark 73.54% of all...... days are non-clear (fraction of direct radiation less than 50%). UAV multispectral imagery acquired in these conditions tends to present low brightness and dynamic ranges, and high noise levels. Another problem is the influence of land cover types on the signal. For instance, over vegetated areas, even...... of a multispectral camera to produce high quality UAV imagery under low but homogeneous irradiance conditions. Laboratory experiments were conducted to link irradiance levels to different camera settings and calibration procedures. Results were tested outdoors over homogeneous and vegetated surfaces...
MAARGHA: A Prototype System for Road Condition and Surface Type Estimation by Fusing Multi-Sensor Data
Directory of Open Access Journals (Sweden)
Deepak Rajamohan
Full Text Available Road infrastructure in countries like India is expanding at a rapid pace and is becoming increasingly difficult for authorities to identify and fix the bad roads in time. Current Geographical Information Systems (GIS lack information about on-road features like road surface type, speed breakers and dynamic attribute data like the road quality. Hence there is a need to build road monitoring systems capable of collecting such information periodically. Limitations of satellite imagery with respect to the resolution and availability, makes road monitoring primarily an on-field activity. Monitoring is currently performed using special vehicles that are fitted with expensive laser scanners and need skilled resource besides providing only very low coverage. Hence such systems are not suitable for continuous road monitoring. Cheaper alternative systems using sensors like accelerometer and GPS (Global Positioning System exists but they are not equipped to achieve higher information levels. This paper presents a prototype system MAARGHA (MAARGHA in Sanskrit language means an eternal path to solution, which demonstrates that it can overcome the disadvantages of the existing systems by fusing multi-sensory data like camera image, accelerometer data and GPS trajectory at an information level, apart from providing additional road information like road surface type. MAARGHA has been tested across different road conditions and sensor data characteristics to assess its potential applications in real world scenarios. The developed system achieves higher information levels when compared to state of the art road condition estimation systems like Roadroid. The system performance in road surface type classification is dependent on the local environmental conditions at the time of imaging. In our study, the road surface type classification accuracy reached 100% for datasets with near ideal environmental conditions and dropped down to 60% for datasets with shadows and
Condition monitoring of industrial infrastructures using distributed fibre optic acoustic sensors
Hicke, Konstantin; Hussels, Maria-Teresa; Eisermann, René; Chruscicki, Sebastian; Krebber, Katerina
Distributed fibre optic acoustic sensing (DAS) can serve as an excellent tool for real-time condition monitoring of a variety of industrial and civil infrastructures. In this paper, we portray a subset of our current research activities investigating the usability of DAS based on coherent optical time-domain reflectometry (C-OTDR) for innovative and demanding condition monitoring applications. Specifically, our application-oriented research presented here aims at acoustic and vibrational condition monitoring of pipelines and piping systems, of rollers in industrial heavy-duty conveyor belt systems and of extensive submarine power cable installations, respectively.
Active carbon filter health condition detection with piezoelectric wafer active sensors
Bao, Jingjing; Giurgiutiu, Victor; Rubel, Glenn O.; Peterson, Gregory W.; Ball, Thomas M.
The impregnated active carbon used in air purification systems degrades over time due to exposure to contamination and mechanical effects (packing, settling, flow channeling, etc.). A novel approach is proposed to detect contamination in active carbon filters by combining the electromechanical impedance spectroscopy (EMIS) and electrochemical impedance spectroscopy (ECIS). ECIS is currently being used to evaluate active carbon filtration material; however, it cannot differentiate the impedance changes due to chemical contamination from those due to mechanical changes. EMIS can detect impedance changes due to mechanical changes. For the research work presented in this paper, Piezoelectric wafer active sensor (PWAS) was used for the EMIS method. Some remarkable new phenomena were unveiled in the detection of carbon filter status. 1. PWAS EMIS can detect the presence of contaminants, such as water and kerosene in the carbon bed 2. PWAS EMIS can monitor changes in mechanical pressure that may be associated with carbon bed packing, settling and flow channeling 3. EMIS and ECIS measurements are consistent with each other and complimentary A tentative simplified impedance model was created to simulate the PWAS-carbon bed system under increasing pressure. Similar impedance change pattern was observed when comparing the simulation results with experimental data.
CRAM: A Conditioned Reflex Action Inspired Adaptive Model for Context Addition in Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Majid Hussain
Full Text Available In Wireless Sensor Networks (WSNs, Context Awareness is typically realized through Context Aware Systems (CASs. Although almost each CAS follows sense-decide-adapt cycle, the notion of context is hardwired into the applications; that is, when an event is triggered, the sense-decide-actuate cycle runs and performs required actuation. In situations, for instance, whenever the same event is triggered, the cycle produces the same actuation through mechanical use of the same resources, posing the same processing and time. In this paper, we propose CRAM, a context added system in which actuations once performed by the system help it to internally evolve by serving as new contexts. As the system is exposed to more situations overtime, its context repository is enriched through such retrospective contexts, gradually letting it perform internal actuation through improved introspective contexts. This internal actuation leads the system towards the evolution of intelligent processing by reducing the independent function of decision in sense-decide-actuate cycle and merging it with new context. Finally, the system reaches a juncture where recurrence of each event proves to be a stimulus for the system to respond impulsively, through priming memory of introspective contexts, to achieve an imitation of learned reflex action resulting into reduced time and energy expenditure.
Replacement Condition Detection of Railway Point Machines Using an Electric Current Sensor
Sa, Jaewon; Choi, Younchang; Chung, Yongwha; Kim, Hee-Young; Park, Daihee; Yoon, Sukhan
Detecting replacement conditions of railway point machines is important to simultaneously satisfy the budget-limit and train-safety requirements. In this study, we consider classification of the subtle differences in the aging effect—using electric current shape analysis—for the purpose of replacement condition detection of railway point machines. After analyzing the shapes of after-replacement data and then labeling the shapes of each before-replacement data, we can derive the criteria that can handle the subtle differences between "does-not-need-to-be-replaced" and "needs-to-be-replaced" shapes. On the basis of the experimental results with in-field replacement data, we confirmed that the proposed method could detect the replacement conditions with acceptable accuracy, as well as provide visual interpretability of the criteria used for the time-series classification. PMID:28146057
Replacement Condition Detection of Railway Point Machines Using an Electric Current Sensor.
Sa, Jaewon; Choi, Younchang; Chung, Yongwha; Kim, Hee-Young; Park, Daihee; Yoon, Sukhan
Detecting replacement conditions of railway point machines is important to simultaneously satisfy the budget-limit and train-safety requirements. In this study, we consider classification of the subtle differences in the aging effect-using electric current shape analysis-for the purpose of replacement condition detection of railway point machines. After analyzing the shapes of after-replacement data and then labeling the shapes of each before-replacement data, we can derive the criteria that can handle the subtle differences between "does-not-need-to-be-replaced" and "needs-to-be-replaced" shapes. On the basis of the experimental results with in-field replacement data, we confirmed that the proposed method could detect the replacement conditions with acceptable accuracy, as well as provide visual interpretability of the criteria used for the time-series classification.
Strain development in a filled epoxy resin curing under constrained and unconstrained conditions as assessed by Fibre Bragg Grating sensors
Directory of Open Access Journals (Sweden)
Full Text Available The influence of adhesion to the mould wall on the released strain of a highly filled anhydride cured epoxy resin (EP, which was hardened in an aluminium mould under constrained and unconstrained condition, was investigated. The shrinkage-induced strain was measured by fibre optical sensing technique. Fibre Bragg Grating (FBG sensors were embedded into the curing EP placed in a cylindrical mould cavity. The cure-induced strain signals were detected in both, vertical and horizontal directions, during isothermal curing at 75 °C for 1000 minutes. A huge difference in the strain signal of both directions could be detected for the different adhesion conditions. Under non-adhering condition the horizontal and vertical strain-time traces were practically identical resulting in a compressive strain at the end of about 3200 ppm, which is a proof of free or isotropic shrinking. However, under constrained condition the horizontal shrinkage in the EP was prevented due to its adhesion to the mould wall. So, the curing material shrunk preferably in vertical direction. This resulted in much higher released compressive strain signals in vertical (10430 ppm than in horizontal (2230 ppm direction. The constrained cured EP resins are under inner stresses. Qualitative information on the residual stress state in the molding was deduced by exploiting the birefringence of the EP.
Cumulative effects of fecal contamination from combined sewer overflows: Management for source water protection.
Jalliffier-Verne, Isabelle; Heniche, Mourad; Madoux-Humery, Anne-Sophie; Galarneau, Martine; Servais, Pierre; Prévost, Michèle; Dorner, Sarah
The quality of a drinking water source depends largely on upstream contaminant discharges. Sewer overflows can have a large influence on downstream drinking water intakes as they discharge untreated or partially treated wastewaters that may be contaminated with pathogens. This study focuses on the quantification of Escherichia coli discharges from combined sewer overflows (CSOs) and the dispersion and diffusion in receiving waters in order to prioritize actions for source water protection. E. coli concentrations from CSOs were estimated from monitoring data at a series of overflow structures and then applied to the 42 active overflow structures between 2009 and 2012 using a simple relationship based upon the population within the drainage network. From these estimates, a transport-dispersion model was calibrated with data from a monitoring program from both overflow structures and downstream drinking water intakes. The model was validated with 15 extreme events such as a large number of overflows (n > 8) or high concentrations at drinking water intakes. Model results demonstrated the importance of the cumulative effects of CSOs on the degradation of water quality downstream. However, permits are typically issued on a discharge point basis and do not consider cumulative effects. Source water protection plans must consider the cumulative effects of discharges and their concentrations because the simultaneous discharge of multiple overflows can lead to elevated E. coli concentrations at a drinking water intake. In addition, some CSOs have a disproportionate impact on peak concentrations at drinking water intakes. As such, it is recommended that the management of CSOs move away from frequency based permitting at the discharge point to focus on the development of comprehensive strategies to reduce cumulative and peak discharges from CSOs upstream of drinking water intakes. Copyright © 2016 Elsevier Ltd. All rights reserved.
Detection of daily activities and sports with wearable sensors in controlled and uncontrolled conditions.
Ermes, M; Pärkka, J; Mantyjarvi, J; Korhonen, I
Physical activity has a positive impact on people's well-being, and it may also decrease the occurrence of chronic diseases. Activity recognition with wearable sensors can provide feedback to the user about his/her lifestyle regarding physical activity and sports, and thus, promote a more active lifestyle. So far, activity recognition has mostly been studied in supervised laboratory settings. The aim of this study was to examine how well the daily activities and sports performed by the subjects in unsupervised settings can be recognized compared to supervised settings. The activities were recognized by using a hybrid classifier combining a tree structure containing a priori knowledge and artificial neural networks, and also by using three reference classifiers. Activity data were collected for 68 h from 12 subjects, out of which the activity was supervised for 21 h and unsupervised for 47 h. Activities were recognized based on signal features from 3-D accelerometers on hip and wrist and GPS information. The activities included lying down, sitting and standing, walking, running, cycling with an exercise bike, rowing with a rowing machine, playing football, Nordic walking, and cycling with a regular bike. The total accuracy of the activity recognition using both supervised and unsupervised data was 89% that was only 1% unit lower than the accuracy of activity recognition using only supervised data. However, the accuracy decreased by 17% unit when only supervised data were used for training and only unsupervised data for validation, which emphasizes the need for out-of-laboratory data in the development of activity-recognition systems. The results support a vision of recognizing a wider spectrum, and more complex activities in real life settings.
Euler technology assessment for preliminary aircraft design employing OVERFLOW code with multiblock structured-grid method
Treiber, David A.; Muilenburg, Dennis A.
The viability of applying a state-of-the-art Euler code to calculate the aerodynamic forces and moments through maximum lift coefficient for a generic sharp-edge configuration is assessed. The OVERFLOW code, a method employing overset (Chimera) grids, was used to conduct mesh refinement studies, a wind-tunnel wall sensitivity study, and a 22-run computational matrix of flow conditions, including sideslip runs and geometry variations. The subject configuration was a generic wing-body-tail geometry with chined forebody, swept wing leading-edge, and deflected part-span leading-edge flap. The analysis showed that the Euler method is adequate for capturing some of the non-linear aerodynamic effects resulting from leading-edge and forebody vortices produced at high angle-of-attack through C(sub Lmax). Computed forces and moments, as well as surface pressures, match well enough useful preliminary design information to be extracted. Vortex burst effects and vortex interactions with the configuration are also investigated.
Force sensor based tool condition monitoring using a heterogeneous ensemble learning model.
Wang, Guofeng; Yang, Yinwei; Li, Zhimeng
Tool condition monitoring (TCM) plays an important role in improving machining efficiency and guaranteeing workpiece quality. In order to realize reliable recognition of the tool condition, a robust classifier needs to be constructed to depict the relationship between tool wear states and sensory information. However, because of the complexity of the machining process and the uncertainty of the tool wear evolution, it is hard for a single classifier to fit all the collected samples without sacrificing generalization ability. In this paper, heterogeneous ensemble learning is proposed to realize tool condition monitoring in which the support vector machine (SVM), hidden Markov model (HMM) and radius basis function (RBF) are selected as base classifiers and a stacking ensemble strategy is further used to reflect the relationship between the outputs of these base classifiers and tool wear states. Based on the heterogeneous ensemble learning classifier, an online monitoring system is constructed in which the harmonic features are extracted from force signals and a minimal redundancy and maximal relevance (mRMR) algorithm is utilized to select the most prominent features. To verify the effectiveness of the proposed method, a titanium alloy milling experiment was carried out and samples with different tool wear states were collected to build the proposed heterogeneous ensemble learning classifier. Moreover, the homogeneous ensemble learning model and majority voting strategy are also adopted to make a comparison. The analysis and comparison results show that the proposed heterogeneous ensemble learning classifier performs better in both classification accuracy and stability.
Interaction of the Faroe Bank Channel overflow with Iceland Basin intermediate waters
Ullgren, Jenny E.; Fer, Ilker; Darelius, Elin; Beaird, Nicholas
The narrow and deep Faroe Bank Channel (FBC) is an important pathway for cold, dense waters from the Nordic Seas to flow across the Iceland-Scotland ridge into the North Atlantic. The swift, turbulent FBC overflow is associated with strong vertical mixing. Hydrographic profiles from a shipboard survey and two Slocum electric gliders deployed during a cruise in May-June 2012 show an intermediate water mass characterized by low salinity and low oxygen concentration between the upper waters of Atlantic origin and the dense overflow water. A weak low-salinity signal originating north-east of Iceland is discernible at the exit of the FBC, but smeared out by intense mixing. Further west (downstream) marked salinity and oxygen minima are found, which we hypothesize are indicators of a mixture of Labrador Sea Water and Intermediate Water from the Iceland Basin. Water mass characteristics vary strongly on short time scales. Low-salinity, low-oxygen water in the stratified interface above the overflow plume is shown to move along isopycnals toward the Iceland-Faroe Front as a result of eddy stirring and a secondary, transverse circulation in the plume interface. The interaction of low-salinity, low-oxygen intermediate waters with the overflow plume already at a short distance downstream of the sill, here reported for the first time, affects the final properties of the overflow waters through entrainment and mixing.
A generalised Dynamic Overflow Risk Assessment (DORA) for Real Time Control of urban drainage systems
DEFF Research Database (Denmark)
Vezzaro, Luca; Grum, Morten
An innovative and generalised approach to the integrated Real Time Control of urban drainage systems is presented. The Dynamic Overflow Risk Assessment (DORA) strategy aims to minimise the expected Combined Sewer Overflow (CSO) risk by considering (i) the water volume presently stored in the drai......An innovative and generalised approach to the integrated Real Time Control of urban drainage systems is presented. The Dynamic Overflow Risk Assessment (DORA) strategy aims to minimise the expected Combined Sewer Overflow (CSO) risk by considering (i) the water volume presently stored...... in the drainage network, (ii) the expected runoff volume (calculated by radar-based nowcast models) and – most important – (iii) the estimated uncertainty of the runoff forecasts. The inclusion of uncertainty allows for a more confident use of Real Time Control (RTC). Overflow risk is calculated by a flexible...... periods, using a simple conceptual model, is presented. Compared to a traditional local control approach, DORA contributed to reduce CSO volumes from the most sensitive points while reducing total CSO volumes discharged from the catchment. Additionally, the results show that the inclusion of forecasts...
The Structure Design of Piezoelectric Poly(vinylidene Fluoride (PVDF Polymer-Based Sensor Patch for the Respiration Monitoring under Dynamic Walking Conditions
Directory of Open Access Journals (Sweden)
Kin-Fong Lei
Full Text Available This study reports a piezoelectric poly(vinylidene fluoride (PVDF polymer-based sensor patch for respiration detections in dynamic walking condition. The working mechanism of respiration signal generation is based on the periodical deformations on a human chest wall during the respiratory movements, which in turn mechanically stretch the piezoelectric PVDF film to generate the corresponding electrical signals. In this study, the PVDF sensing film was completely encapsulated within the sensor patch forming a mass-spring-damper mechanical system to prevent the noises generated in a dynamic condition. To verify the design of sensor patch to prevent dynamic noises, experimental investigations were carried out. Results demonstrated the respiration signals generated and the respiratory rates measured by the proposed sensor patch were in line with the same measurements based on a commercial respiratory effort transducer both in a static (e.g., sitting or dynamic (e.g., walking condition. As a whole, this study has developed a PVDF-based sensor patch which is capable of monitoring respirations in a dynamic walking condition with high fidelity. Other distinctive features include its small size, light weight, ease of use, low cost, and portability. All these make it a promising sensing device to monitor respirations particularly in home care units.
High-resolution marine flood modelling coupling overflow and overtopping processes: framing the hazard based on historical and statistical approaches
Nicolae Lerma, Alexandre; Bulteau, Thomas; Elineau, Sylvain; Paris, François; Durand, Paul; Anselme, Brice; Pedreros, Rodrigo
A modelling chain was implemented in order to propose a realistic appraisal of the risk in coastal areas affected by overflowing as well as overtopping processes. Simulations are performed through a nested downscaling strategy from regional to local scale at high spatial resolution with explicit buildings, urban structures such as sea front walls and hydraulic structures liable to affect the propagation of water in urban areas. Validation of the model performance is based on hard and soft available data analysis and conversion of qualitative to quantitative information to reconstruct the area affected by flooding and the succession of events during two recent storms. Two joint probability approaches (joint exceedance contour and environmental contour) are used to define 100-year offshore conditions scenarios and to investigate the flood response to each scenario in terms of (1) maximum spatial extent of flooded areas, (2) volumes of water propagation inland and (3) water level in flooded areas. Scenarios of sea level rise are also considered in order to evaluate the potential hazard evolution. Our simulations show that for a maximising 100-year hazard scenario, for the municipality as a whole, 38 % of the affected zones are prone to overflow flooding and 62 % to flooding by propagation of overtopping water volume along the seafront. Results also reveal that for the two kinds of statistic scenarios a difference of about 5 % in the forcing conditions (water level, wave height and period) can produce significant differences in terms of flooding like +13.5 % of water volumes propagating inland or +11.3 % of affected surfaces. In some areas, flood response appears to be very sensitive to the chosen scenario with differences of 0.3 to 0.5 m in water level. The developed approach enables one to frame the 100-year hazard and to characterize spatially the robustness or the uncertainty over the results. Considering a 100-year scenario with mean sea level rise (0.6 m), hazard
Observed and modelled stability of overflow across the Greenland-Scotland ridge.
Olsen, Steffen M; Hansen, Bogi; Quadfasel, Detlef; Østerhus, Svein
Across the Greenland-Scotland ridge there is a continuous flow of cold dense water, termed 'overflow', from the Nordic seas to the Atlantic Ocean. This is a main contributor to the production of North Atlantic Deep Water that feeds the lower limb of the Atlantic meridional overturning circulation, which has been predicted to weaken as a consequence of climate change. The two main overflow branches pass the Denmark Strait and the Faroe Bank channel. Here we combine results from direct current measurements in the Faroe Bank channel for 1995-2005 with an ensemble hindcast experiment for 1948-2005 using an ocean general circulation model. For the overlapping period we find a convincing agreement between model simulations and observations on monthly to interannual timescales. Both observations and model data show no significant trend in volume transport. In addition, for the whole 1948-2005 period, the model indicates no persistent trend in the Faroe Bank channel overflow or in the total overflow transport, in agreement with the few available historical observations. Deepening isopycnals in the Norwegian Sea have tended to decrease the pressure difference across the Greenland-Scotland ridge, but this has been compensated for by the effect of changes in sea level. In contrast with earlier studies, we therefore conclude that the Faroe Bank channel overflow, and also the total overflow, did not decrease consistently from 1950 to 2005, although the model does show a weakening total Atlantic meridional overturning circulation as a result of changes south of the Greenland-Scotland ridge.
Bacterial diversity impacts as a result of combined sewer overflow in a polluted waterway
Directory of Open Access Journals (Sweden)
O. Calderon
Full Text Available Newtown Creek is an industrial waterway and former tidal wetland in New York City. It is one of the most polluted water bodies in the United States and was designated as a superfund site in 2010. For over a century, organic compounds, heavy metals, and other forms of industrial pollution have disrupted the creek's environment. The creek is also impacted by discharges from twenty combined sewer overflow pipes, which may deposit raw sewage or partially treated wastewater directly into the creek during heavy or sustained rain events. Combined sewer overflow events and associated nutrient over-enrichment at the creek drive eutrophication and subsequent hypoxia. At the current study, three sites were sampled one week apart during a dry period and a wet period, where indication of a combined sewage overflow event could be detected. 16s rRNA high-throughput sequencing from these three sites collectively yielded over 1000 species of bacteria belonging to twenty-two classes. Based on these data, it is hypothesized that differences identified in the microbiome on wet versus dry days are as a result of combined sewage overflow, street runoff, and additional fluctuations in the creek's environment associated with rain. It was found that after a combined sewer overflows event, the levels of Gamma Proteobacteria increased while the levels of Actinobacteria decreased. However, levels of bacteria stayed relatively unchanged at a site further away from combined sewer overflows discharge. Species found in Newtown Creek include pelagic, marine, human and animal pathogens, hydrocarbonoclastic, and other environmental microbes.
Quality Changes of N-3 PUFAs Enriched and Conventional Eggs under Different Home Storage Conditions with Wireless Sensor Network
Directory of Open Access Journals (Sweden)
Wenkang Li
Full Text Available Omega-3 polyunsaturated fatty acids (n-3 PUFAs enriched eggs are popular for their enrichment of PUFAs, but their freshness and quality are prone to decline with time, particularly if storage conditions are not well maintained. Home storage is the last but a neglected important tach in eggs supply chain, but few studies are available on the egg storage in the home stage. This study aimed to evaluate the internal quality change of both n-3 PUFAs enriched and conventional eggs by simulating eggs stored at consumers' home in refrigeration and under room temperature. The egg quality indices (Haugh unit, yolk index, weight, and albumen pH were adopted and analyzed for both storage conditions. Wireless sensor network (WSN was used for real-time monitoring of the temperature and humidity during storage. The results showed that temperature, humidity and time of storage all have an influence on the freshness of both n-3 PUFAs enriched and conventional eggs and there is no significant difference happened to n-3 PUFAs enriched eggs and conventional eggs. Refrigeration can decelerate the quality deterioration of both n-3 PUFAs enriched and conventional eggs and consumers should be educated about how to maintain the internal quality of eggs during home storage.
Quality assessment of a storm overflow, by using different frequency monitoring (northern France)
Ivanovsky, Anastasia; Dumoulin, David; Criquet, Justine; Prygiel, Jean; Pohu, Jérôme; Hottin, Frédéric; Billon, Gabriel
The Heron lake is a storm-water pond of 30 hectare constructed in the 70's to avoid the flooding in the city of Villeneuve d'Ascq (Lille urban area in Northern France). This facility could also receive some untreated urban wastewaters during high rainfall events. The water level is regulated by automatic pumps, which periodically discharge the overflow into a natural watercourse, the Marque River. Located in an urban area, the lake is qualified as eutrophic because of the high nutrients concentration, which stimulates the presence of cyanobacteria. Recently, the invasive macrophyte Elodea nuttallii colonized the lake. This proliferation causes ecological troubles like anoxic events or even obstruction of the pumps, thereby increasing the risk of flooding. Two types of monitoring (low and high frequencies) were implemented to assess the functioning of this lake and to estimate its impact to the river. The low frequency monitoring consisted on punctual screenings on the dissolved phase and monthly grab samplings from February 2014 to February 2015. Physicochemical parameters (oxygen, temperature, conductivity, pH, solid particulate matter, dissolved organic carbon) and nutrients (NO3-, NH4+ and PO43-) were recorded. Additionally, a high frequency monitoring was undertaken (with measurements every 10 minutes) was performed by using a buoy equipped with different sensors for measuring oxygen, turbidity, temperature, conductivity, pH and phytoplankton pigments. Furthermore, both the discharge lake flow and the pluviometry were recorded at the scale of the day. Although all the data are not yet fully interpreted, several key points have already been evidenced: (i) at the entrance of the lake, the water is enriched in urban sewage; (ii) some significant differences of oxygenation exist between the entrance and the rest of the lake due to both waste waters inputs in the entrance channel and atmosphere-water interactions; (iii) eutrophication occurs at the beginning of the
Fault-diagnosis applications. Model-based condition monitoring. Acutators, drives, machinery, plants, sensors, and fault-tolerant systems
Energy Technology Data Exchange (ETDEWEB)
Isermann, Rolf [Technische Univ. Darmstadt (DE). Inst. fuer Automatisierungstechnik (IAT)
Supervision, condition-monitoring, fault detection, fault diagnosis and fault management play an increasing role for technical processes and vehicles in order to improve reliability, availability, maintenance and lifetime. For safety-related processes fault-tolerant systems with redundancy are required in order to reach comprehensive system integrity. This book is a sequel of the book ''Fault-Diagnosis Systems'' published in 2006, where the basic methods were described. After a short introduction into fault-detection and fault-diagnosis methods the book shows how these methods can be applied for a selection of 20 real technical components and processes as examples, such as: Electrical drives (DC, AC) Electrical actuators Fluidic actuators (hydraulic, pneumatic) Centrifugal and reciprocating pumps Pipelines (leak detection) Industrial robots Machine tools (main and feed drive, drilling, milling, grinding) Heat exchangers Also realized fault-tolerant systems for electrical drives, actuators and sensors are presented. The book describes why and how the various signal-model-based and process-model-based methods were applied and which experimental results could be achieved. In several cases a combination of different methods was most successful. The book is dedicated to graduate students of electrical, mechanical, chemical engineering and computer science and for engineers. (orig.)
A potential sanitary sewer overflow treatment technology: fixed-media bioreactors.
Tao, Jing; Mancl, Karen M; Tuovinen, Olli H
Under certain conditions, sanitary sewer overflows (SSOs) containing raw wastewater may be discharged to public land and can contribute to environmental and public health issues. Although this problem has attracted the attention of local, state, and federal government and regulators, relatively little SSO abatement research has been published. This study used fixed-media bioreactors, a proven onsite technology in rural areas, to treat wet weather SSO wastewater and reduce its effects on the receiving water environment. The results of this 32-month laboratory study showed that fixed-media bioreactors, especially sand bioreactors, efficiently removed organic matter, solids, and nutrients during six-hour simulated SSO peak flows. Five-day biochemical oxygen demand (BODs) of the simulated SSO varied between 40 and 125 mg/L. The average effluent concentration of BOD5 was 13 mg/L in sand bioreactors at a hydraulic loading rate of 20.4 cm/h. In addition to having high hydraulic loadings, SSO events occur infrequently. This irregularity requires that treatment systems quickly start up and effectively treat wastewater after a period of no flow. This research found that an interval up to six months between two SSO peak flows did not affect the bioreactor performance. Based on this work, fixed-media bioreactors have the potential to reduce the effects of SSOs on the water environment by following proper design parameters and operation strategies. The pollution loading of approximately 18 g BODs/m2 x h is recommended for the efficient performance of sand bioreactors in the SSO treatment.
Evaluating rain gardens as a method to reduce the impact of sewer overflows in sources of drinking water.
Autixier, Laurène; Mailhot, Alain; Bolduc, Samuel; Madoux-Humery, Anne-Sophie; Galarneau, Martine; Prévost, Michèle; Dorner, Sarah
The implications of climate change and changing precipitation patterns need to be investigated to evaluate mitigation measures for source water protection. Potential solutions need first to be evaluated under present climate conditions to determine their utility as climate change adaptation strategies. An urban drainage network receiving both stormwater and wastewater was studied to evaluate potential solutions to reduce the impact of combined sewer overflows (CSOs) in a drinking water source. A detailed hydraulic model was applied to the drainage basin to model the implementation of best management practices at a drainage basin scale. The model was calibrated and validated with field data of CSO flows for seven events from a survey conducted in 2009 and 2010. Rain gardens were evaluated for their reduction of volumes of water entering the drainage network and of CSOs. Scenarios with different levels of implementation were considered and evaluated. Of the total impervious area within the basin directly connected to the sewer system, a maximum of 21% could be alternately directed towards rain gardens. The runoff reductions for the entire catchment ranged from 12.7% to 19.4% depending on the event considered. The maximum discharged volume reduction ranged from 13% to 62% and the maximum peak flow rate reduction ranged from 7% to 56%. Of concern is that in-sewer sediment resuspension is an important process to consider with regard to the efficacy of best management practices aimed at reducing extreme loads and concentrations. Rain gardens were less effective for large events, which are of greater importance for drinking water sources. These practices could increase peak instantaneous loads as a result of greater in-sewer resuspension during large events. Multiple interventions would be required to achieve the objectives of reducing the number, total volumes and peak contaminant loads of overflows upstream of drinking water intakes. Copyright © 2014 Elsevier B.V. All
Fine particle emission potential from overflowing areas of Tarim River in the Tarim Basin
In the low-precipitation zone (Tarim Basin, wind erosion and fugitive dust emission is a recognized problem. There is limited information, however, regarding wind erosion on river overflowing areas, areas of temporal flooding, in the Tarim Basin. The objectives o...
Analysis of Two-Level Support Systems with Time-Dependent Overflow - A Banking Application
DEFF Research Database (Denmark)
Barth, Wolfgang; Manitz, Michael; Stolletz, Raik
In this paper, we analyze the performance of call centers of financial service providers with two levels of support and a time-dependent overflow mechanism. Waiting calls from the front-office queue flow over to the back office if a waiting-time limit is reached and at least one back-office agent...
The effect of intravenously applied (-)adrenaline, taken up by and released from sympathetic nerves, on swimming exercise-induced noradrenaline overflow in permanently cannulated adrenal demedullated rats was studied. Adrenaline (100 ng/min) was infused for 2 h, during which a plasma concentration
Hydraulic Modeling and Evolutionary Optimization for Enhanced Real-Time Decision Support of Combined Sewer Overflows
Zimmer, A. L.; Minsker, B. S.; Schmidt, A. R.; Ostfeld, A.
Real-time mitigation of combined sewer overflows (CSOs) requires evaluation of multiple operational strategies during rapidly changing rainfall events. Simulation models for hydraulically complex systems can effectively provide decision support for short time intervals when coupled with efficient optimization. This work seeks to reduce CSOs for a test case roughly based on the North Branch of the Chicago Tunnel and Reservoir Plan (TARP), which is operated by the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC). The North Branch tunnel flows to a junction with the main TARP system. The Chicago combined sewer system alleviates potential CSOs by directing high interceptor flows through sluice gates and dropshafts to a deep tunnel. Decision variables to control CSOs consist of sluice gate positions that control water flow to the tunnel as well as a treatment plant pumping rate that lowers interceptor water levels. A physics-based numerical model is used to simulate the hydraulic effects of changes in the decision variables. The numerical model is step-wise steady and conserves water mass and momentum at each time step by iterating through a series of look-up tables. The look-up tables are constructed offline to avoid extensive real-time calculations, and describe conduit storage and water elevations as a function of flow. A genetic algorithm (GA) is used to minimize CSOs at each time interval within a moving horizon framework. Decision variables are coded at 15-minute increments and GA solutions are two hours in duration. At each 15-minute interval, the algorithm identifies a good solution for a two-hour rainfall forecast. Three GA modifications help reduce optimization time. The first adjustment reduces the search alphabet by eliminating sluice gate positions that do not influence overflow volume. The second GA retains knowledge of the best decision at the previous interval by shifting the genes in the best previous sequence to initialize search at
A Bayesian network model to assess the public health risk associated with wet weather sewer overflows discharging into waterways.
Goulding, R; Jayasuriya, N; Horan, E
Overflows from sanitary sewers during wet weather, which occur when the hydraulic capacity of the sewer system is exceeded, are considered a potential threat to the ecological and public health of the waterways which receive these overflows. As a result, water retailers in Australia and internationally commit significant resources to manage and abate sewer overflows. However, whilst some studies have contributed to an increased understanding of the impacts and risks associated with these events, they are relatively few in number and there still is a general lack of knowledge in this area. A Bayesian network model to assess the public health risk associated with wet weather sewer overflows is presented in this paper. The Bayesian network approach is shown to provide significant benefits in the assessment of public health risks associated with wet weather sewer overflows. In particular, the ability for the model to account for the uncertainty inherent in sewer overflow events and subsequent impacts through the use of probabilities is a valuable function. In addition, the paper highlights the benefits of the probabilistic inference function of the Bayesian network in prioritising management options to minimise public health risks associated with sewer overflows. Copyright © 2012. Published by Elsevier Ltd.
An Information Theoretic Framework and Self-organizing Agent- based Sensor Network Architecture for Power Plant Condition Monitoring
Energy Technology Data Exchange (ETDEWEB)
Loparo, Kenneth; Kolacinski, Richard; Threeanaew, Wanchat; Agharazi, Hanieh
A central goal of the work was to enable both the extraction of all relevant information from sensor data, and the application of information gained from appropriate processing and fusion at the system level to operational control and decision-making at various levels of the control hierarchy through: 1. Exploiting the deep connection between information theory and the thermodynamic formalism, 2. Deployment using distributed intelligent agents with testing and validation in a hardware-in-the loop simulation environment. Enterprise architectures are the organizing logic for key business processes and IT infrastructure and, while the generality of current definitions provides sufficient flexibility, the current architecture frameworks do not inherently provide the appropriate structure. Of particular concern is that existing architecture frameworks often do not make a distinction between ``data'' and ``information.'' This work defines an enterprise architecture for health and condition monitoring of power plant equipment and further provides the appropriate foundation for addressing shortcomings in current architecture definition frameworks through the discovery of the information connectivity between the elements of a power generation plant. That is, to identify the correlative structure between available observations streams using informational measures. The principle focus here is on the implementation and testing of an emergent, agent-based, algorithm based on the foraging behavior of ants for eliciting this structure and on measures for characterizing differences between communication topologies. The elicitation algorithms are applied to data streams produced by a detailed numerical simulation of Alstom's 1000 MW ultra-super-critical boiler and steam plant. The elicitation algorithm and topology characterization can be based on different informational metrics for detecting connectivity, e.g. mutual information and linear correlation.
A Galvanic Sensor for Monitoring the Corrosion Condition of the Concrete Reinforcing Steel: Relationship Between the Galvanic and the Corrosion Currents
Directory of Open Access Journals (Sweden)
Elsa Vaz Pereira
Full Text Available This work reports a study carried out on the design and performance of galvanic and polarization resistance sensors to be embedded in concrete systems for permanent monitoring of the corrosion condition of reinforcing steel, aiming to establish a correlation between the galvanic currents, Igal, and the corrosion currents, Icorr, estimated from the polarization resistance, Rp. Sensors have been tested in saturated Ca(OH2 aqueous solutions, under a variety of conditions, simulating the most important parameters that can accelerate the corrosion of concrete reinforcing steel, such as carbonation, ingress of chloride ions, presence or absence of O2. For all the conditions, the influence of temperature (20 to 55 ºC has also been considered. From this study, it could be concluded that the galvanic currents are sensitive to the various parameters following a trend similar to that of the Rp values. A relationship between the galvanic and the corrosion current densities was obtained and the limiting values of the Igal, indicative of the state condition of the reinforcing steel for the designed sensor, were established.
Transport estimates and variability of the Denmark Strait Overflow, 1996-2016
Jochumsen, Kerstin; Moritz, Martin; Quadfasel, Detlef; Nunes, Nuno; Larsen, Karin M.; Hansen, Bogi; Käse, Rolf H.; Valdimarsson, Hedinn; Jonsson, Steingrimur
The major export route of dense water flow from the Nordic Seas into the North Atlantic occurs in the deep channel in Denmark Strait. Downstream, the volume of this water is about doubled by entrainment and forms the prominent bottom layer of the Deep Western Boundary Current in the Subpolar North Atlantic. The dense water outflow through Denmark Strait has been monitored with moored instruments (typically two) since 1996, using Acoustic Doppler Current Profilers (ADCPs) anchored close to the bottom in floatation bodies. Volume transport calculations in Denmark Strait have been based so far on these ADCPs anchored in the deeper part of the channel, which were regressed to the total transport of dense water through the Strait in a model. The resulting transport has been used in many publications. Here, we present a new calculation method to estimate the volume transport of the Denmark Strait Overflow, based on results from an extended five mooring array deployed in 2014/15. At the same time, a correction is proposed for a bias detected on some ADCPs (the 'Workhorse Long Ranger' devices working at 75 kHz frequency), which led to earlier underestimation of the flow in the deep plume core. However, the new array included measurements at shallower positions on the Greenland shelf, where the net transports were found to be small. Using the new method, the mean dense overflow transport is estimated to be -3.07±0.56 Sv, without a significant trend. Besides variations on the eddy scale, an analysis of the fluctuations in the velocity field using empirical orthogonal functions (EOF) reveals three dominant modes of variability: the first mode is roughly barotropic and corresponds to pulsations of the plume, the second mode represents the laterally shifting component of the plume core position, and the third mode indicates the impact of the vertical extension, i.e. the varying overflow thickness. Furthermore, a similar approach is applied to the volume transport time series
Synthesis of Sensor Fish Data for Assessment of Fish Passage Conditions at Turbines, Spillways, and Bypass Facilities – Phase 1: The Dalles Dam Spillway Case Study
Energy Technology Data Exchange (ETDEWEB)
Deng, Zhiqun; Serkowski, John A.; Fu, Tao; Carlson, Thomas J.; Richmond, Marshall C.
This report summarizes the characterization of spillway passage conditions at The Dalles Dam in 2006 and the effort to complete a comprehensive database for data sets from The Dalles Dam spillway Sensor Fish and balloon-tagged live fish experiments. Through The Dalles Dam spillway case study, Pacific Northwest National Laboratory (PNNL) researchers evaluated the database as an efficient means for accessing and retrieving system-wide data for the U.S Army Corps of Engineers (USACE).
[Performance characteristics of root zone moisture and water potential sensors for greenhouses in the conditions of extended space flight].
Podolskiy, I G; Strugov, O M; Bingham, G E
The investigation was performed using greenhouse Lada in the Russian segment of the International space station (ISS RS) as part of space experiment Plants-2 during ISS missions 5 through to 22. A set of 6 point moisture sensors embedded in the root zone (turface particles of 1-2 mm in diam.) and 4 tensiometers inside root modules (RM) were used to monitor moisture content and water potential in the root zone. The purpose was to verify functionality and to test performance of the sensors in the spacefight environment. It was shown that with the average RZ moisture content of 80% the measurement error of the sensors do not exceed ± 1.5%. Dynamic analysis of the tensiometers measurements attests that error in water potential measurements does not exceed ± 111 Pa.
Deep water overflow in the Faroe Bank Channel; modelling, processes, and impact
DEFF Research Database (Denmark)
Rullyanto, Arief
or tides, but also deep beneath the surface, where deep-water currents circulate waters throughout the world's oceans. In certain very-localized regions, the flow of the deep-water has to travel over a sill in a narrow submarine channel. This overflow process mixes the deep water with overlying waters......, creating new water masses with distinct temperature, salinity and density characteristics. The change of water mass characteristics not only affects the local environment, but also far distant regions. The Faroe Bank Channel, which is located in the southern part of Faroe Islands, is one of the most...... important overflow regions in the world. It connects two huge ocean basins, the North Atlantic Ocean and the Nordic Seas, and the water mass produced there is an important ingredient of North Atlantic Deep Water, a water mass that found very nearly everywhere in the deep basins of the world's oceans...
Combined Sewer Overflow pretreatment with chemical coagulation and a particle settler for improved peracetic acid disinfection
DEFF Research Database (Denmark)
Chhetri, Ravi Kumar; Bonnerup, Arne; Andersen, Henrik Rasmus
Full scale disinfection by peracetic acid (PAA) was achieved on Combined Sewer Overflow (CSO) water, which was pre-treated physically by a fast settling-filtration unit. Disinfection of untreated CSO water using PAA was compared to treatment using a particle separator (HydroSeparator®) and additi......Full scale disinfection by peracetic acid (PAA) was achieved on Combined Sewer Overflow (CSO) water, which was pre-treated physically by a fast settling-filtration unit. Disinfection of untreated CSO water using PAA was compared to treatment using a particle separator (Hydro......Separator®) and additional coagulation with poly-aluminum-chloride. Disinfection for Enterococcus increased with the applied dose of PAA and additional improvement was achieved when it was preceded by chemical coagulation with 5 mg L−1 poly-aluminum-chloride. When Enterococcus was reduced by treatment in the Hydro...
The Importance of Lake Overflow Floods for Early Martian Landscape Evolution: Insights From Licus Vallis
Goudge, T. A.; Fassett, C. I.
Open-basin lake outlet valleys are incised when water breaches the basin-confining topography and overflows. Outlet valleys record this flooding event and provide insight into how the lake and surrounding terrain evolved over time. Here we present a study of the paleolake outlet Licus Vallis, a >350 km long, >2 km wide, >100 m deep valley that heads at the outlet breach of an approx.30 km diameter impact crater. Multiple geomorphic features of this valley system suggest it records a more complex evolution than formation from a single lake overflow flood. This provides unique insight into the paleohydrology of lakes on early Mars, as we can make inferences beyond the most recent phase of activity..
Metamorphic Testing Integer Overflow Faults of Mission Critical Program: A Case Study
Directory of Open Access Journals (Sweden)
Zhanwei Hui
Full Text Available For mission critical programs, integer overflow is one of the most dangerous faults. Different testing methods provide several effective ways to detect the defect. However, it is hard to validate the testing outputs, because the oracle of testing is not always available or too expensive to get, unless the program throws an exception obviously. In the present study, the authors conduct a case study, where the authors apply a metamorphic testing (MT method to detect the integer overflow defect and alleviate the oracle problem in testing critical program of Traffic Collision Avoidance System (TCAS. Experimental results show that, in revealing typical integer mutations, compared with traditional safety property testing method, MT with a novel symbolic metamorphic relation is more effective than the traditional method in some cases.
Use long short-term memory to enhance Internet of Things for combined sewer overflow monitoring
Zhang, Duo; Lindholm, Geir; Ratnaweera, Harsha
Combined sewer overflow causes severe water pollution, urban flooding and reduced treatment plant efficiency. Understanding the behavior of CSO structures is vital for urban flooding prevention and overflow control. Neural networks have been extensively applied in water resource related fields. In this study, we collect data from an Internet of Things monitoring CSO structure and build different neural network models for simulating and predicting the water level of the CSO structure. Through a comparison of four different neural networks, namely multilayer perceptron (MLP), wavelet neural network (WNN), long short-term memory (LSTM) and gated recurrent unit (GRU), the LSTM and GRU present superior capabilities for multi-step-ahead time series prediction. Furthermore, GRU achieves prediction performances similar to LSTM with a quicker learning curve.
Using Multiple Antibiotic Resistance Profiles of Coliforms as a Tool to Investigate Combined Sewer Overflow Contamination.
Dhiman, Gaurav; Burns, Emma N; Morris, David W
Studies have shown that fecal contamination can be determined by conducting multiple antibiotic resistance (MAR) analyses. The hypothesis is if bacteria exhibit resistance, they are likely to be derived from organisms exposed to antimicrobial agents. Therefore, this project seeks to apply MAR analysis to nonpoint source (NPS) and combined sewer overflow (CSO) areas along the Anacostia River in Washington, DC. Presumptive E. coli was isolated from NPS and CSO samples and tested with eight different antimicrobial agents to assess MAR indices. Isolates from CSO sources showed significantly greater resistance (p coliforms are associated with CSO overflows, indicating that pollution-derived coliform levels are strongly linked to antimicrobial resistance. The implementation of this method as an index for water quality in the remediation of the Anacostia River has the ability to serve as a model and monitoring tool for the rehabilitation of urban watersheds.
A Model-Based Virtual Sensor for Condition Monitoring of Li-Ion Batteries in Cyber-Physical Vehicle Systems
Directory of Open Access Journals (Sweden)
Luciano Sánchez
Full Text Available A model-based virtual sensor for assessing the health of rechargeable batteries for cyber-physical vehicle systems (CPVSs is presented that can exploit coarse data streamed from on-vehicle sensors of current, voltage, and temperature. First-principle-based models are combined with knowledge acquired from data in a semiphysical arrangement. The dynamic behaviour of the battery is embodied in the parametric definition of a set of differential equations, and fuzzy knowledge bases are embedded as nonlinear blocks in these equations, providing a human understandable reading of the State of Health of the CPVS that can be easily integrated in the fleet through-life management.
Effects of combined sewer overflows on a periurban stream ecosystem: Methodological approach
Breil, P.; Lafont, M.; Vivier, A.; Namour, P.; Schmitt, L.
International audience; Here we develop from a long term field experiment an assessment method of interstitial fauna resilience to combined sewer overflows (CSOs) effect. We address the case of small water courses for which the ratio of CSOs to natural flow can be 1 to much more. Biotic material was collected in the benthic and hyporheic layers. Biotic material focussed mainly on oligocheates species whose diversity, species category and abundance are resumed into metrics, called functional t...
Comparing overflow and wave-overtopping induced breach initiation mechanisms in an embankment breach experiment
van Damme Myron; Ponsioen Luc; Herrero Monica; Peeters Patrik
As part of the SAFElevee project Delft University of Technology collabored with Flanders Hydraulics Research, and Infram B.V. in the preperation and execution of a full scale embankment breach experiment in November 2015. This breach experiment was performed on an 3.5m high embankment with a sand core and clay outer layer situated along the tidal river Scheldt in Belgium near Schellebelle. During the experiment a wave overtopping simulator and overflow simulator were used to initiate a breach...
Assessment of the effect of rainfall dynamics on the storm overflow performance
Directory of Open Access Journals (Sweden)
Szeląg Bartosz
Full Text Available Assessment of the effect of rainfall dynamics on the storm overfl ow performance. This research study analyzes the effect of the rainfall characteristics (total and maximum 10-, 15- and 30-minute rainfall depth, its duration, the dry weather period on the performance of the emergency overflow weir located at the inflow to an existing treatment plant. The analyses used the numerical calculation results of the inflow hydrographs performed in the SWMM (Storm Water Management Model program on the basis of six-year-long rainfall measurement sequence. The obtained simulation results for the analysed catchment allowed for the performance of statistical analyses, which demonstrated that the volume of stormwater discharge, the maximum instantaneous flow and the share of stormwater volume discharged through the emergency overflow weir in relation to the total volume of the inflow hydrograph from the catchment are affected by the maximum 30-minute rainfall depth, whereas the discharge duration is affected by the depth of the catchment rainfall layer. Taking into account the results of statistical and hydraulic calculations it can be concluded that in the case of the analysed catchment the performance of the emergency overflow weir is affected to the greatest extent by the rainfall intensity distribution.
The effects of combined sewer overflow events on riverine sources of drinking water.
Madoux-Humery, Anne-Sophie; Dorner, Sarah; Sauvé, Sébastien; Aboulfadl, Khadija; Galarneau, Martine; Servais, Pierre; Prévost, Michèle
This study was set out to investigate the impacts of Combined Sewer Overflows (CSOs) on the microbiological water quality of a river used as a source of drinking water treatment plants. Escherichia coli concentrations were monitored at various stations of a river segment located in the Greater Montreal Area including two Drinking Water Intakes (DWIs) in different weather conditions (dry weather and wet weather (precipitation and snowmelt period)). Long-term monitoring data (2002-2011) at DWIs revealed good microbiological water quality with E. coli median concentrations of 20 and 30 CFU/100 mL for DWI-1 and DWI-2 respectively. However, E. coli concentration peaks reached up to 510 and 1000 CFU/100 mL for both DWIs respectively. Statistical Process Control (SPC) analysis allowed the identification of E. coli concentration peaks in almost a decade of routine monitoring data at DWIs. Almost 80% of these concentrations were linked to CSO discharges caused by precipitation exceeding 10 mm or spring snowmelt. Dry weather monitoring confirmed good microbiological water quality. Wet weather monitoring showed an increase of approximately 1.5 log of E. coli concentrations at DWIs. Cumulative impacts of CSO discharges were quantified at the river center with an increase of approximately 0.5 log of E. coli concentrations. Caffeine (CAF) was tested as a potential chemical indicator of CSO discharges in the river and CAF concentrations fell within the range of previous measurements performed for surface waters in the same area (∼20 ng/L). However, no significant differences were observed between CAF concentrations in dry and wet weather, as the dilution potential of the river was too high. CSO event based monitoring demonstrated that current bi-monthly or weekly compliance monitoring at DWIs underestimate E. coli concentrations entering DWIs and thus, should not be used to quantify the risk at DWIs. High frequency event-based monitoring is a desirable approach to
An evaluation of wearable sensors and their placements for analyzing construction worker's trunk posture in laboratory conditions.
Lee, Wonil; Seto, Edmund; Lin, Ken-Yu; Migliaccio, Giovanni C
This study investigates the effect of sensor placement on the analysis of trunk posture for construction activities using two off-the-shelf systems. Experiments were performed using a single-parameter monitoring wearable sensor (SPMWS), the ActiGraph GT9X Link, which was worn at six locations on the body, and a multi-parameter monitoring wearable sensor (MPMWS), the Zephyr BioHarness™3, which was worn at two body positions. One healthy male was recruited and conducted 10 experiment sessions to repeat measurements of trunk posture within our study. Measurements of upper-body thoracic bending posture during the lifting and lowering of raised deck materials in a laboratory setting were compared against video-captured observations of posture. The measurements from the two sensors were found to be in agreement during slow-motion symmetric bending activities with a target bending of ≤45°. However, for asymmetric bending tasks, when the SPMWS was placed on the chest, its readings were substantially different from those of the MPMWS worn on the chest or under the armpit. Copyright © 2017 Elsevier Ltd. All rights reserved.
Composition and variability of the Denmark Strait Overflow Water in a high-resolution numerical model hindcast simulation
Behrens, Erik; Vâge, Kjetil; Harden, Benjamin; Biastoch, Arne; Böning, Claus W.
The upstream sources and pathways of the Denmark Strait Overflow Water and their variability have been investigated using a high-resolution model hindcast. This global simulation covers the period from 1948 to 2009 and uses a fine model mesh (1/20°) to resolve mesoscale features and the complex current structure north of Iceland explicitly. The three sources of the Denmark Strait Overflow, the shelfbreak East Greenland Current (EGC), the separated EGC, and the North Icelandic Jet, have been analyzed using Eulerian and Lagrangian diagnostics. The shelfbreak EGC contributes the largest fraction in terms of volume and freshwater transport to the Denmark Strait Overflow and is the main driver of the overflow variability. The North Icelandic Jet contributes the densest water to the Denmark Strait Overflow and shows only small temporal transport variations. During summer, the net volume and freshwater transports to the south are reduced. On interannual time scales, these transports are highly correlated with the large-scale wind stress curl around Iceland and, to some extent, influenced by the North Atlantic Oscillation, with enhanced southward transports during positive phases. The Lagrangian trajectories support the existence of a hypothesized overturning loop along the shelfbreak north of Iceland, where water carried by the North Icelandic Irminger Current is transformed and feeds the North Icelandic Jet. Monitoring these two currents and the region north of the Iceland shelfbreak could provide the potential to track long-term changes in the Denmark Strait Overflow and thus also the AMOC.
Characterization of Fish Passage Conditions through a Francis Turbine, Spillway, and Regulating Outlet at Detroit Dam, Oregon, Using Sensor Fish, 2009
Energy Technology Data Exchange (ETDEWEB)
Duncan, Joanne P.; Carlson, Thomas J.
Fish passage conditions through two spillways, a Francis turbine, and a regulating outlet (RO) at Detroit Dam on the North Santiam River in Oregon were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers (USACE), Portland District, using Sensor Fish devices. The objective of the study was to describe and compare passage exposure conditions, identifying potential fish injury regions within the routes. The study was performed in July, October, and December 2009 concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish data were analyzed to estimate 1) exposure conditions, particularly exposure to severe strike, collision, and shear events by passage route sub-regions; 2) differences in passage conditions between passage routes; and 3) relationships to live-fish injury and mortality data estimates. Comparison of the three passage routes evaluated at Detroit Dam indicates that the RO passage route through the 5-ft gate opening was relatively the safest route for fish passage under the operating conditions tested; turbine passage was the most deleterious. These observations were supported also by the survival and malady estimates obtained from live-fish testing. Injury rates were highest for turbine and spillway passage. However, none of the passage routes tested is safe for juvenile salmonid passage.
Characterization of Fish Passage Conditions through a Francis Turbine and Regulating Outlet at Cougar Dam, Oregon, Using Sensor Fish, 2009–2010
Energy Technology Data Exchange (ETDEWEB)
Duncan, Joanne P.
Fish passage conditions through a Francis turbine and a regulating outlet (RO) at Cougar Dam on the south fork of the McKenzie River in Oregon were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, using Sensor Fish devices. The objective of the study was to describe and compare passage exposure conditions, identifying potential fish injury regions encountered during passage via specific routes. The RO investigation was performed in December 2009 and the turbine evaluation in January 2010, concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish data were analyzed to estimate 1) exposure conditions, particularly exposure to severe collision, strike, and shear events by passage route sub-regions; 2) differences in passage conditions between passage routes; and 3) relationships to live-fish injury and mortality data estimates. Comparison of the three passage routes evaluated at Cougar Dam indicates that the RO passage route through the 3.7-ft gate opening was relatively the safest route for fish passage under the operating conditions tested; turbine passage was the most deleterious. These observations were supported also by the survival and malady estimates obtained from live-fish testing. Injury rates were highest for turbine passage. Compared to mainstem Columbia River passage routes, none of the Cougar Dam passage routes as tested are safe for juvenile salmonid passage.
Increasing NADH oxidation reduces overflow metabolism in Saccharomyces cerevisiae
DEFF Research Database (Denmark)
Vemuri, Goutham; Eiteman, M.A; McEwen, J.E
Crabtree effect.'' The yeast Saccharomyces cerevisiae has served as an important model organism for studying the Crabtree effect. When subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from purely...... effect is due to limited respiratory capacity or is caused by glucose-mediated repression of respiration. When respiration in S. cerevisiae was increased by introducing a heterologous alternative oxidase, we observed reduced aerobic ethanol formation. In contrast, increasing nonrespiratory NADH oxidation...... NADH dehydrogenases in S. cerevisiae. These results indicate that NADH oxidase localizes in the cytosol, whereas alternative oxidase is directed to the mitochondria....
Directory of Open Access Journals (Sweden)
M. Venkatesulu
Full Text Available Solutions of initial value problems associated with a pair of ordinary differential systems (L1,L2 defined on two adjacent intervals I1 and I2 and satisfying certain interface-spatial conditions at the common end (interface point are studied.
Water Quality of Combined Sewer Overflows, Stormwater, and Streams, Omaha, Nebraska, 2006-07
Vogel, Jason R.; Frankforter, Jill D.; Rus, David L.; Hobza, Christopher M.; Moser, Matthew T.
The U.S. Geological Survey, in cooperation with the City of Omaha, investigated the water quality of combined sewer overflows, stormwater, and streams in the Omaha, Nebraska, area by collecting and analyzing 1,175 water samples from August 2006 through October 2007. The study area included the drainage area of Papillion Creek at Capeheart Road near Bellevue, Nebraska, which encompasses the tributary drainages of the Big and Little Papillion Creeks and Cole Creek, along with the Missouri River reach that is adjacent to Omaha. Of the 101 constituents analyzed during the study, 100 were detected in at least 1 sample during the study. Spatial and seasonal comparisons were completed for environmental samples. Measured concentrations in stream samples were compared to water-quality criteria for pollutants of concern. Finally, the mass loads of water-quality constituents in the combined sewer overflow discharges, stormwater outfalls, and streams were computed and compared. The results of the study indicate that combined sewer overflow and stormwater discharges are affecting the water quality of the streams in the Omaha area. At the Papillion Creek Basin sites, Escherichia coli densities were greater than 126 units per 100 milliliters in 99 percent of the samples (212 of 213 samples analyzed for Escherichia coli) collected during the recreational-use season from May through September (in 2006 and 2007). Escherichia coli densities in 76 percent of Missouri River samples (39 of 51 samples) were greater than 126 units per 100 milliliters in samples collected from May through September (in 2006 and 2007). None of the constituents with human health criteria for consumption of water, fish, and other aquatic organisms were detected at levels greater than the criteria in any of the samples collected during this study. Total phosphorus concentrations in water samples collected in the Papillion Creek Basin were in excess of the U.S. Environmental Protection Agency's proposed
Transcriptional profiling of human breast cancer cells cultured under microgravity conditions revealed the key role of genetic gravity sensors previously detected in Drosophila melanogaster
Valdivia-Silva, Julio E.; Lavan, David; Diego Orihuela-Tacuri, M.; Sanabria, Gabriela
Currently, studies in Drosophila melanogaster has shown emerging evidence that microgravity stimuli can be detected at the genetic level. Analysis of the transcriptome in the pupal stage of the fruit flies under microgravity conditions versus ground controls has suggested the presence of a few candidate genes as "gravity sensors" which are experimentally validated. Additionally, several studies have shown that microgravity causes inhibitory effects in different types of cancer cells, although the genes involved and responsible for these effects are still unknown. Here, we demonstrate that the genes suggested as the sensors of gravitational waves in Drosophila melanogaster and their human counterpart (orthologous genes) are highly involved in carcinogenesis, proliferation, anti-apoptotic signals, invasiveness, and metastatic potential of breast cancer cell tumors. The transcriptome analyses suggested that the observed inhibitory effect in cancer cells could be due to changes in the genetic expression of these candidates. These results encourage the possibility of new therapeutic targets managed together and not in isolation.
Pressure and concentration conditions prevailing in the diffusion channel and cathode chamber of an oxygen limiting current sensor; Die Druck- und Konzentrationsverteilung im Diffusionskanal und Kathodenraum einer Sauerstoffgrenzstromsonde
Energy Technology Data Exchange (ETDEWEB)
Gruenwald, W. [Robert Bosch GmbH, Zentralbereich Forschung und Vorausentwicklung, Abt. FV/FLT, Stuttgart (Germany)
The pressure and concentration conditions prevailing in the diffusion channel and cathode chamber of an oxygen limiting-current sensor can be ascertained by solving the respective diffusion equation while taking into account the attendant marginal conditions. In the article under consideration, a number of different types of diffusion in the diffusion channel are considered, namely the gas phase diffusion with and without pressure compensation, and the Knudsen diffusion without pressure compensation. Linear and ring-shaped geometries for the diffusion channel and the cathode chamber are considered. The procedure enables theoretical predictions on the behavior of limiting-current sensors under different test conditions. When a comparison is made between the predictions and experimental results which are already available, it is impossible to reach a clear-cut decision as to whether superimposed convection currents are responsible for pressure compensation in the channel. Here, a large-model sensor could be used to reach a clear-cut decision provided no changes occur to the flow conditions taking the Reynolds number into account. (orig.) [Deutsch] Die Druck- und Konzentrationsverhaeltnisse im Diffusionskanal und Kathodenraum einer Sauerstoffgrenzstromsonde koennen durch Loesen der jeweiligen Diffusionsgleichung unter Beruecksichtigung der dazu gehoerigen Randbedingungen ermittelt werden. In der vorliegenden Arbeit wurden verschiedene Diffusionsarten im Diffusionskanal betrachtet, und zwar die Gasphasendiffusion mit und ohne Druckausgleich sowie die Knudsen-Diffusion ohne Druckausgleich. Betrachtet werden lineare und ringfoermige Geometrien fuer den Diffusionskanal und den Kathodenraum. Das Verfahren erlaubt theoretische Vorhersagen ueber das Verhalten von Grenzstromsonden unter verschiedenen Versuchsbedingungen. Beim Vergleich der Vorhersagen mit vorliegenden experimentellen Ergebnissen kann nicht eindeutig entschieden werden, ob im Kanal ein Druckausgleich durch
Overflow control mechanism (OCM) for Ethernet passive optical networks (EPONs)
Hajduczenia, Marek; da Silva, Henrique J. A.; Monteiro, Paulo P.
The nonfragmentable nature of Ethernet data frames, as well as operation of the priority oriented packet schedulers in the optical network units, in conjunction with heavy network load conditions and the lack of detailed knowledge about the queue's composition at the optical line terminal (OLT) level, result in the creation of upstream channel slot remainders. The existing methods, in the form of nonpreemptive packet schedulers and multithreshold reporting process defined vaguely by the IEEE 802.3-2005 standard, result in either increased packet delay or Ethernet passive optical network (EPON) system incompatibility, respectively, since threshold processing was never officially defined in the scope of the respective EPON standard. We propose an alternative approach, based on basic modifications of the standard and extended GATE multipoint control protocol data unit format and meaning, allowing for the OLT packet scheduling agent to grant always exactly the requested slot size, thus preventing creation of any upstream channel slot remainders. It is estimated that, on average, ˜3% of upstream channel bandwidth can be salvaged when slot remainders are absent in the upstream channel transmission.
Tidally induced lateral dispersion of the Storfjorden overflow plume
Directory of Open Access Journals (Sweden)
F. Wobus
Full Text Available We investigate the flow of brine-enriched shelf water from Storfjorden (Svalbard into Fram Strait and onto the western Svalbard Shelf using a regional set-up of NEMO-SHELF, a 3-D numerical ocean circulation model. The model is set up with realistic bathymetry, atmospheric forcing, open boundary conditions and tides. The model has 3 km horizontal resolution and 50 vertical levels in the sh-coordinate system which is specially designed to resolve bottom boundary layer processes. In a series of modelling experiments we focus on the influence of tides on the propagation of the dense water plume by comparing results from tidal and non-tidal model runs. Comparisons of non-tidal to tidal simulations reveal a hotspot of tidally induced horizontal diffusion leading to the lateral dispersion of the plume at the southernmost headland of Spitsbergen which is in close proximity to the plume path. As a result the lighter fractions in the diluted upper layer of the plume are drawn into the shallow coastal current that carries Storfjorden water onto the western Svalbard Shelf, while the dense bottom layer continues to sink down the slope. This bifurcation of the plume into a diluted shelf branch and a dense downslope branch is enhanced by tidally induced shear dispersion at the headland. Tidal effects at the headland are shown to cause a net reduction in the downslope flux of Storfjorden water into the deep Fram Strait. This finding contrasts previous results from observations of a dense plume on a different shelf without abrupt topography.
Humanitarian logistics: the establishment of the nimbusdroid pluviometric monitoring system to rainfall spates, floods and overflows in the rochdale neighborhood
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Camila Umbelino Carvalho
Full Text Available Spates, floods and overflows are natural disasters and anthropogenic character responsible for strong impact on society. The fact that they have difficult prognosis makes the means of providing for them is uncertain, passing the condition of hostages to the populations of the areas affected by these events. Therefore, it is necessary the intervention of the Humanitarian Logistics in order to ensure emergency aid to victims. One of the factors responsible for the complexity of acting Humanitarian Logistics is the prevention of disasters through the flow of information and communications. As a possible solution, are used the rainfall monitoring systems to control water levels. Thus, the aim of this paper was to develop a rainfall monitoring system called Nimbusdroid the Rochdale neighborhood, which emphasizes the high number of incidence of these disasters. In metodological terms, bibliographical research had been used for the constitution of the theoretical basement, followed of a study of case in the quarter of the Rochdale. . As its focus, it is a qualitative and quantitative research .According to the method of approach is deductive research. Not only used in the monitoring water levels, the Nimbusdroid system forwards messages and supplies information to the applicatory site and of the same in form of alert in real time. When compared with the ALERT SMS – rainfall monitoring installed in the Osasco city - Nimbusdroid system has advantages in its functionality, a time that the ALERT SMS is unknown and requires a prior registration, different of Nimbusdroid.
Managing of gas sensing characteristic of a reduced graphene oxide based gas sensor by the change in synthesis condition: A new approach for electronic nose design
Energy Technology Data Exchange (ETDEWEB)
Alizadeh, Taher, E-mail: email@example.com [Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Hamedsoltani, Leyla [Department of Applied Chemistry, Faculty of Science, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of)
Natural graphite was oxidized and exfoliated via two different methods, leading to two types of graphene oxide (GO) materials. The obtained materials were reduced by three different reducing agents including: hydrazine hydrate, ascorbic acid and sodium borohydride, giving thus six kinds of reduced graphene oxide (RGO) materials. The obtained materials were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The RGOs were then used to fabricate different gas sensors and their electrical resistances were recorded upon exposing to various volatile organic compounds vapors (VOCs). Gas sensing selectivity of each RGO was significantly affected by the synthesis condition. The RGO-based sensor array was fabricated and its capability for discrimination of seven kinds of VOCs was evaluated, utilizing principal component analysis and cluster analysis methods. Loading plot indicated that the presence of five RGO-based sensors could effectively discriminate the aimed vapors. The electronic nose, containing five kinds of RGOs, was used for the classification of seven kinds of VOCs at their different concentrations. - Highlights: • Two oxidation procedures and three reducing agents were utilized to produce six kinds of RGOs. • The synthesized different RGOs exhibited significantly different sensing behaviors. • Seven kinds of organic vapors were chosen for the evaluation of discrimination power of EN. • Using PCA, it was found that seven of six RFGOs were appropriate number to use in final EN. • The developed EN was capable of properly discrimination of tested vapors.
Regional simulations of the Faroe Bank Channel overflow using a σ-coordinate ocean model
Seim, Knut S.; Fer, Ilker; Berntsen, Jarle
Gravity-driven overflow of cold, deep and intermediate water from the Norwegian Sea through the Faroe Bank Channel carries significant volume flux and contributes to the ventilation of the deep North Atlantic Ocean. Here we present results from regional simulations of the Faroe Bank Channel overflow using a terrain-following ( σ-coordinate) ocean model with fine resolution near the sea bed. The model results are compared with observations of hydrography, currents and turbulence conducted in 2008. Turbulent dissipation rate and eddy diffusivity profiles inferred from the observations are used in refining the parameters of the turbulence closure. The model reproduces the observed vertical structure of the enhanced dissipation and diffusivity in the bottommost 50-60 m exceptionally well. In this region, shear-induced mixing dominates and is found to be well-represented by the applied second order turbulence closure models. Farther away from the boundary, however, in the 100-m thick interfacial layer and above the plume-ambient interface, the model does not resolve the observed mixing. The contribution of turbulence from breaking internal waves is one of the processes not represented in the model with significant consequences for observed entrainment and mixing. Regular sub-inertial oscillations (eddies) at 4-4.5 day period develop downstream of the sill, consistent with the observations. When averaged over several eddy events, the evolution of section-averaged plume properties over the oscillation period shows that the eddies significantly affect mixing and the descent rate of the plume. At a section 60 km downstream of the sill, eddies lead to periodic and abrupt cross-isobath descent of the overflow plume and an increase in dissipation rate by one order of magnitude.
The Influence of Polymerization Condition to Optical Properties of Poly-o-toludine Films for PH Sensor Application
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Yanti Sabarinah
Full Text Available Properties of poly-o-toludine film strongly bonded to non polar substrate was studied for application as optical pH sensor. Characterization of film in various pH value is carried out by recording absorbance curve using uv-visible spectrophotometer. All poly-o-toluidine film was then found to be applicable as optical pH sensor in the pH range of 2.0- 6.0. Further computational processing by means of curve fitting into logaritmic trend will allow expansion of measurement to the pH range of 2.0-8.0. Sensitivity of pH response was highest in poly-o-toluidine film fabricate at HCl 1.0 M and at 12 hours of dipping time. This paper also studied hysteresis effect in pH response. It was concluded that poly-o-toluidine salt exposed to basic pH will not be easily regenerated. For this reason, poly-o-toluidine film will only be suitable for single usage of pH measurement.
A Power-Efficient Clustering Protocol for Coal Mine Face Monitoring with Wireless Sensor Networks Under Channel Fading Conditions.
Ren, Peng; Qian, Jiansheng
This study proposes a novel power-efficient and anti-fading clustering based on a cross-layer that is specific to the time-varying fading characteristics of channels in the monitoring of coal mine faces with wireless sensor networks. The number of active sensor nodes and a sliding window are set up such that the optimal number of cluster heads (CHs) is selected in each round. Based on a stable expected number of CHs, we explore the channel efficiency between nodes and the base station by using a probe frame and the joint surplus energy in assessing the CH selection. Moreover, the sending power of a node in different periods is regulated by the signal fade margin method. The simulation results demonstrate that compared with several common algorithms, the power-efficient and fading-aware clustering with a cross-layer (PEAFC-CL) protocol features a stable network topology and adaptability under signal time-varying fading, which effectively prolongs the lifetime of the network and reduces network packet loss, thus making it more applicable to the complex and variable environment characteristic of a coal mine face.
A Power-Efficient Clustering Protocol for Coal Mine Face Monitoring with Wireless Sensor Networks Under Channel Fading Conditions
Directory of Open Access Journals (Sweden)
Peng Ren
Full Text Available This study proposes a novel power-efficient and anti-fading clustering based on a cross-layer that is specific to the time-varying fading characteristics of channels in the monitoring of coal mine faces with wireless sensor networks. The number of active sensor nodes and a sliding window are set up such that the optimal number of cluster heads (CHs is selected in each round. Based on a stable expected number of CHs, we explore the channel efficiency between nodes and the base station by using a probe frame and the joint surplus energy in assessing the CH selection. Moreover, the sending power of a node in different periods is regulated by the signal fade margin method. The simulation results demonstrate that compared with several common algorithms, the power-efficient and fading-aware clustering with a cross-layer (PEAFC-CL protocol features a stable network topology and adaptability under signal time-varying fading, which effectively prolongs the lifetime of the network and reduces network packet loss, thus making it more applicable to the complex and variable environment characteristic of a coal mine face.
Performance of the Widely-Used CFD Code OVERFLOW on the Pleides Supercomputer
Guruswamy, Guru P.
Computational performance studies were made for NASA's widely used Computational Fluid Dynamics code OVERFLOW on the Pleiades Supercomputer. Two test cases were considered: a full launch vehicle with a grid of 286 million points and a full rotorcraft model with a grid of 614 million points. Computations using up to 8000 cores were run on Sandy Bridge and Ivy Bridge nodes. Performance was monitored using times reported in the day files from the Portable Batch System utility. Results for two grid topologies are presented and compared in detail. Observations and suggestions for future work are made.
Fecal overflow often affects children with chronic constipation that appears after the age of 2 years.
Kammacher Guerreiro, Mélissa; Bettinville, Aurore; Herzog, Denise
Chronic functional constipation with or without encopresis is a common problem in the pediatric population, and the prevalence of encopresis may be underestimated. The aim of this study was to assess the prevalence and risk factors for overflow incontinence in patients with chronic constipation seen at a pediatric gastroenterology consultation. A retrospective study of 270 files of patients seen between 1997 and 2012 was conducted, and a classification according to Rome III criteria was done. Among 145 (53.7%) boys and 125 (46.2%) girls, 117 had overflow incontinence (43.3%) - 41 (35%) girls and 76 (65%) boys. The first symptoms of chronic constipation appeared at a median age of 30 and 33 months in encopretic and 16 and 12 months in nonencopretic girls and boys, respectively. The first specialized consultation took place after a median disease duration of 26.5 and 24 months in encopretic and 16 and 9 months in nonencopretic girls and boys, respectively. A history of stool retention and the presence of scybala at examination, but not of pain at defecation or anal fissure, were associated with encopresis. The onset of chronic constipation after the age of 2 years, a longer disease duration, male gender, and a history of stool retention were seen as risk factors for the development of encopresis in patients with chronic functional constipation. © The Author(s) 2014.
Deep ventilation in the Okinawa Trough induced by Kerama Gap overflow
Nishina, Ayako; Nakamura, Hirohiko; Park, Jae-Hun; Hasegawa, Daisuke; Tanaka, Yuki; Seo, Seongbong; Hibiya, Toshiyuki
Near-bottom water flowing over the Kerama Gap's sills is thought to ventilate the deep water below ˜1100 m depth in the Okinawa Trough and then upwell with 5-10 years residence time. The present study follows up on this phenomenon, using comprehensive profile data of temperature, salinity, dissolved oxygen, currents and turbulence obtained by intensive shipboard observations performed in June 2013 and June 2014 in the region. Strong near-bottom subtidal flow with speeds exceeding 0.5 m s-1 was observed within a layer of about 100 m thickness over the western side of the peak of the main sill. Temperature and salinity sections along the Kerama Gap indicated some depressions and overturns of the deep water downstream of the strong overflow, suggesting the existence of breaking internal gravity waves and hydraulic jumps. Associated vertical diffusivities, estimated using the Thorpe scale and the buoyancy frequency, were three to four orders of magnitude larger than typical values observed in the thermocline of the open ocean (˜10-5 m2 s-1). The dissolved oxygen section also indicated strong vertical mixing and associated upwelling with the entrainment of the near-bottom overflow water into the lower thermocline beneath the Kuroshio in the Okinawa Trough. The present study not only supports the previous conceptual model but also provides new evidence that the Okinawa Trough is an upwelling location where nutrient rich Philippine Sea intermediate water is sucked up into the lower thermocline below the Kuroshio.
Mesoscale mixing of the Denmark Strait Overflow in the Irminger Basin
M. Koszalka, Inga.; W. N. Haine, Thomas; G. Magaldi, Marcello
The Denmark Strait Overflow (DSO) is a major export route for dense waters from the Nordic Seas forming the lower limb of the Atlantic Meridional Overturning Circulation, an important element of the climate system. Mixing processes along the DSO pathway influence its volume transport and properties contributing to the variability of the deep overturning circulation. They are poorly sampled by observations, however, which hinders development of a proper DSO representation in global circulation models. We employ a high resolution regional ocean model of the Irminger Basin to quantify impact of the mesoscale flows on DSO mixing focusing on geographical localization and the time-modulation of water property changes. The model reproduces the observed bulk warming of the DSO plume 100-200 km downstream of the Denmark Strait sill. It also reveals that mesoscale variability of the overflow ('DSO-eddies', of 20-30 km extent and a time scale of 2-5 day) modulates water property changes and turbulent mixing, diagnosed with the vertical shear of horizontal velocity and the eddy heat flux divergence. The space-time localization of the DSO mixing and warming and the role of coherent mesoscale structures should be explored by turbulence measurements and factored into the coarse circulation models.
Full scale evaluation of combined sewer overflows disinfection using performic acid in a sea-outfall pipe
DEFF Research Database (Denmark)
Chhetri, Ravi Kumar; Flagstad, Rasmus; Sonne Munch, Ebbe
Pollution of surface waters with pathogens from combined sewer overflows limits recreational use of surface waters. Large retention basins are a satisfactory solution but they are rarely sufficient for economic or space reasons. Fast disinfection during the overflow is an alternative, but few...... methods are known and each has problems. This work evaluated for the first time the full-scale disinfection using performic acid by the removal of the two currently regulated indicator bacteria for bathing water quality, E. coli and Enterococcus. Experiments were performed at a sewage bypass through a sea...
Development of an early warning sensor and network for brown-\\0xAD\\0x2010out conditions.
Brownout conditions on motorways are caused by windblown dust and sand from upwind areas where : soils are susceptible to wind erosion. Owing in part to prolonged droughts that have dried : soils and denuded vegetation and biological crusts, large, m...
ESPRIT-Like Two-Dimensional DOA Estimation for Monostatic MIMO Radar with Electromagnetic Vector Received Sensors under the Condition of Gain and Phase Uncertainties and Mutual Coupling.
Zhang, Dong; Zhang, Yongshun; Zheng, Guimei; Feng, Cunqian; Tang, Jun
In this paper, we focus on the problem of two-dimensional direction of arrival (2D-DOA) estimation for monostatic MIMO Radar with electromagnetic vector received sensors (MIMO-EMVSs) under the condition of gain and phase uncertainties (GPU) and mutual coupling (MC). GPU would spoil the invariance property of the EMVSs in MIMO-EMVSs, thus the effective ESPRIT algorithm unable to be used directly. Then we put forward a C-SPD ESPRIT-like algorithm. It estimates the 2D-DOA and polarization station angle (PSA) based on the instrumental sensors method (ISM). The C-SPD ESPRIT-like algorithm can obtain good angle estimation accuracy without knowing the GPU. Furthermore, it can be applied to arbitrary array configuration and has low complexity for avoiding the angle searching procedure. When MC and GPU exist together between the elements of EMVSs, in order to make our algorithm feasible, we derive a class of separated electromagnetic vector receiver and give the S-SPD ESPRIT-like algorithm. It can solve the problem of GPU and MC efficiently. And the array configuration can be arbitrary. The effectiveness of our proposed algorithms is verified by the simulation result.
Atmospheric Corrections and Multi-Conditional Algorithm for Multi-Sensor Remote Sensing of Suspended Particulate Matter in Low-to-High Turbidity Levels Coastal Waters
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Stéfani Novoa
lower than 7%. Despite some inaccuracies in ρw retrieval, we demonstrate that the SPM concentration can be reliably estimated using OLI, MODIS and VIIRS, regardless of their differences in spatial and spectral resolutions. Match-ups between the OLI-derived SPM concentration and autonomous field measurements from the Loire and Gironde estuaries' monitoring networks provided satisfactory results. The multi-sensor approach together with the multi-conditional algorithm presented here can be applied to the latest generation of ocean color sensors (namely Sentinel2/MSI and Sentinel3/OLCI to study SPM dynamics in the coastal ocean at higher spatial and temporal resolutions.
Lead Detection and Mapping with Reference to Relationships Between Scale, Sensor Characteristics, Surface Conditions and Atmospheric Properties
2.40. The wideband (350-695 nm) pyrheliometer data were collected at the NOAA Climate Monitoring and Diagnostics Laboratory's Barrow Observatory ( CMDL ...Analysis of meteorological conditions during AGASP-IV: March 30-April 23, 1992. I NOAA Tech. Memo. ERL CMDL -5, NOAA/ERL/Climate Monitoring and
Evidence of Nipigon Phase Overflow From Glacial Lake Agassiz in Northwestern Lake Superior.
Wattrus, N. J.; Colman, S. M.; Gary, J.
season of the project, which focused on mapping the lake floor expression of the later (Nipigon Phase) overflows. These post-Marquette deposits include subsurface fan deposits and coarse-grained strata that are buried below a thin sequence of Holocene sediments. These overflow deposits are found at the entrance to Nipigon Bay, a drainage pathway from Glacial Lake Agassiz known to be active during the Nipigon Phase of Lake Agassiz, and possibly at other discharge locations. Erosion features suggestive of high discharge scour events also occur in several places in the study area. The seismic stratigraphic model generated from these data will be used to analyze data collected next year off Thunder Bay, where the earlier overflows linked to the Younger Dryas have been postulated.
Statistically based sustainable re-design of stormwater overflow control systems in urban catchments
Ganora, Daniele; Isacco, Silvia; Claps, Pierluigi
Control and reduction of pollution from stormwater overflow is a major concern for municipalities to manage the quality of the receiving water bodies according to the Framework Water Directive 2000/60/CE. In this regard, assessment studies of the potential pollution load from sewer networks recognize the need for adaptation and upgrade of existing drainage systems, which can be achieved with either traditional water works (detention tanks, increase of wastewater treatment plant capacity, etc.) or even Nature-based solutions (constructed wetlands, restored floodplains, etc.) sometimes used in combination. Nature-based solutions are recently receiving consistent attentions as they are able to enhance urban and degraded environments being, in the same time, more resilient and adaptable to climatic and anthropic changes than most traditional engineering works. On the other hand, restoration of the urban environment using natural absorbing surfaces requires diffuse interventions, high costs and a considerable amount of time. In this work we investigate how simple, economically-sustainable and quick solutions to the problem at hand can be addressed by changes in the management rules when pumping stations play a role in sewer systems. In particular, we provide a statistically-based framework to be used in the calibration of the management rules, facing improved quality of overflows from sewer systems. Typical pumping rules favor a massive delivery of stormwater volumes to the wastewater treatment plans, requiring large storage tanks in the sewer network, heavy pumping power and reducing the efficiency of the treatment plant due to pollutant dilution. In this study we show that it is possible to optimize the pumping rule in order to reduce pumped volumes to the plant (thus saving energy), while simultaneously keeping high pollutant concentration. On the other hand, larger low-concentration overflow volumes are released outside the sewer network with respect to the standard
Usefulness of a large field of view sensor for physicochemical, textural, and yield predictions under industrial goat cheese (Murcia al Vino) manufacturing conditions.
Rovira, S; García, V; Ferrandini, E; Carrión, J; Castillo, M; López, M B
The applicability of a light backscatter sensor with a large field of view was tested for on-line monitoring of coagulation and syneresis in a goat cheese (Murcia al Vino) manufactured under industrial conditions. Cheesemaking was carried out concurrently in a 12-L pilot vat and a 10,000-L industrial vat following the normal cheesemaking protocol. Cheese moisture, whey fat content, hardness, springiness, and adhesiveness were measured during syneresis. The results obtained show that cutting time is best predicted by considering the coagulation ratio at the inflection point and the percentage increase in the ratio during coagulation, with no need for the first derivative. The large field of view reflectance ratio provided good results for the prediction of moisture content, yield, hardness, springiness, and adhesiveness of the final cheese. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Determination of micropollutants in combined sewer overflows and their removal in a wastewater treatment plant (Seoul, South Korea).
Ryu, Jaena; Oh, Jeill; Snyder, Shane A; Yoon, Yeomin
The present study investigated the occurrence of 29 selected micropollutants such as endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs) in surface waters and wastewaters in Seoul (South Korea) during both dry and wet weather conditions. The study area was selected based on the lack of available information regarding the suspected contamination of rivers/creeks by EDCs and PPCPs in the Seoul region and the presence of a wastewater treatment plant (WWTP), which serves approximately 4.1 million inhabitants and has a design capacity of 1,297 × 10(3) m(3)/day. Many target compounds (83 %) were detected in samples collected from wastewater treatment influent/effluent, creek water, and combined sewer overflow (CSO). The total EDC/PPCP concentrations were as follows: WWTP influent (69,903 ng/L) > WWTP effluent (50,175 ng/L) >3 creek samples (16,035-44,446 ng/L) during dry weather, and WWTP influent (53,795 ng/L) > WWTP bypass (38,653 ng/L) >5 creek samples (15,260-29,113 ng/L) >2 CSO samples (11,109-11,498 ng/L) during wet weather. EDCs and PPCPs were found to be present at high daily loads (65.1 and 69.8 kg/day during dry and wet weather, respectively) in the WWTP effluent. Compound removal by the WWTP varied significantly by compound: caffeine, diclofenac, ibuprofen, naproxen, and propylparaben (>90 %), and acesulfame, DEET, iohexol, iopromide, and iopamidol (hypothesis that the efficiency of removal of EDCs and PPCPs is strongly dependent on both removal mechanism (e.g., biodegradation, adsorption to sludge, and oxidation by chlorine) and compound physicochemical properties (e.g., pK a and hydrophobicity).
Prejunctional histamine H-3-receptors inhibit electrically evoked endogenous noradrenaline overflow in the portal vein of freely moving rats
Smit, J; Coppes, Rob P.; van Tintelen, Eric J.J.; Roffel, A.F.; Zaagsma, Johan
The effects of intra-arterial injection of different doses of the selective histamine H-3-receptor agonist R-alpha-methylhistamine and the selective histamine H-3-receptor antagonist thioperamide on basal and electrically evoked noradrenaline overflow in the portal vein as well as on mean arterial
Occurrence of enrofloxacin in overflows from animal lot and residential sewage lagoons and a receiving-stream.
Ikem, Abua; Lin, Chung-Ho; Broz, Bob; Kerley, Monty; Thi, Ho Le
Enrofloxacin (ENRO), a fluoroquinolone, was quantified in overflows from an animal lot and residential sewage lagoons and in a receiving-stream (Gans Creek). The concentrations of ENRO in samples was determined by high-performance liquid chromatography - tandem mass spectrometry. In total, ninety samples including duplicates were analyzed during several monthly sampling campaigns. The samples collected represented the residential sewage lagoon overflow (RLO), animal lot lagoon overflow (ALLO), the combined overflows (RLO and ALLO), and Gans Creek (upstream, midstream and downstream positions). The frequency of detection of ENRO was 90% for RLO and 100% for both ALLO and Gans Creek. The highest concentration of ENRO (0.44 μg/L) was found in ALLO sample collected during high precipitation. ENRO levels found in RLO samples ranged from < LOQ to 259 ng/L and the highest value observed also coincided with high flow. The levels of ENRO found in Gans Creek ranged from 17-216 ng/L. A preliminary ecotoxicological assessment was conducted through calculation of the risk quotients (RQs) for organisms based on the ratio of the measured environmental concentrations in this study to the predicted-no-effect-concentrations (acute and chronic effect) data. From the RQs, high risks were observed for Microcystis aeruginosa (cyanobacteria; RQ = 4.4); Anabaena flosaquae (cyanobacteria; RQ = 1.3); and Lemna minor (aquatic vascular plant; RQ = 2.0). The long-term effects of mixtures of PHCs on Gans Creek watershed are probable.
Laboratory and field investigation of chemical disinfection of combined sewer overflow in Copenhagen area
DEFF Research Database (Denmark)
Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper
We investigated the possibility to apply performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA to Escherichia coli (E. coli) and enterococcus were studied in batch scale...... and pre-field experiment. In batch scale experiment 2.5 mg·L -1 PAA removed around 4 log unit of E. coli and enterococcus from CSO with long contact time. Removal of E. coli and enterococcus from CSO were always around or above 3 log unit using 2-4 mg·L -1 PFA with short contact time in batch scale...... and pre-field experiment. There were no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA, slight toxicological effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic event. Disinfection...
Chemical disinfection of combined sewer overflow waters using performic acid or peracetic acids
DEFF Research Database (Denmark)
Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper
We investigated the possibility of applying performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA towards Escherichia coli (E. coli) and Enterococcus was studied in batch......-scale and pre-field experiments. In the batch-scale experiment, 2.5 mg L− 1 PAA removed approximately 4 log unit of E. coli and Enterococcus from CSO with a 360 min contact time. The removal of E. coli and Enterococcus from CSO was always around or above 3 log units using 2–4 mg L− 1 PFA; with a 20 min contact...... time in both batch-scale and pre-field experiments. There was no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA; a slight toxic effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic...
Study on several temperature control methods of non heated overflow container
Yang, Haozhe
For a simple water overflow container, we try to find the best solution through which we can keep the temperature as close as possible to the initial temperature without wasting too much water. We build models in time and space. Model in time: We mainly consider convective heat transfer of water and air, heat transfer of container and evaporation of water.we get curves of temperature versus time under different situations. Through calculating and comparing the total water consumption of each program,find out the best plan. Model in space:We build two sub models in the model in space. The difference is the position of added water.we can get some images about the temperature changes with distance in different layers, and find the best strategy.
Monitoring and robust adaptive control of fed-batch cultures of microorganisms exhibiting overflow metabolism [abstract
Directory of Open Access Journals (Sweden)
Vande Wouwer, A.
Full Text Available Overflow metabolism characterizes cells strains that are likely to produce inhibiting by-products resulting from an excess of substrate feeding and a saturated respiratory capacity. The critical substrate level separating the two different metabolic pathways is generally not well defined. Monitoring of this kind of cultures, going from model identification to state estimation, is first discussed. Then, a review of control techniques which all aim at maximizing the cell productivity of fed-batch fermentations is presented. Two main adaptive control strategies, one using an estimation of the critical substrate level as set-point and another regulating the by-product concentration, are proposed. Finally, experimental investigations of an adaptive RST control scheme using the observer polynomial for the regulation of the ethanol concentration in Saccharomyces cerevisiae fed-batch cultures ranging from laboratory to industrial scales, are also presented.
The impact of combined sewage overflows on the viral contamination of receiving waters.
Rodríguez, Roberto A; Gundy, Patricia M; Rijal, Geeta K; Gerba, Charles P
The contribution of combined sewer overflows (CSO) to the viral contamination of receiving waters was determined. Adenovirus concentrations were determined using the Primary Liver Carcinoma (PLC/PRF/5) cell line and confirmed by Polymerase Chain Reaction (PCR). Norovirus concentration was determined using the Most Probable Number (MPN) and Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Seventy-five water samples were collected during dry weather and 50 samples were collected during wet weather. CSO events significantly increased the concentration of culturable viruses, adenoviruses, and noroviruses in the receiving waters (P effects (CPE), adenoviruses were detected in 41% of the positive cell cultures, and noroviruses in 6% of the concentrates by direct RT-PCR. During wet weather, 100% of the samples were positive by CPE, 84% for adenoviruses, and 40% in the concentrates for norovirus. Our results demonstrate that CSOs can contribute significant viral loading to receiving waters.
Micropollutants in stormwater runoff and combined sewer overflow in the Copenhagen area, Denmark
DEFF Research Database (Denmark)
Birch, Heidi; Mikkelsen, Peter Steen; Jensen, J.K.
Stormwater runoff contains a broad range of micropollutants. In Europe a number of these substances are regulated through the Water Framework Directive, which establishes Environmental Quality Standards (EQSs) for surface waters. Knowledge about discharge of these substances through stormwater...... runoff and combined sewer overflows (CSOs) is essential to ensure compliance with the EQSs. Results from a screening campaign including more than 50 substances at four stormwater discharge locations and one CSO in Copenhagen are reported here. Heavy metal concentrations were detected at levels similar...... to earlier findings, e.g., with copper found at concentrations up to 13 times greater than the Danish standard for surface waters. The concentration of polyaromatic hydrocarbons (PAHs) exceeded the EQSs by factors up to 500 times for stormwater and 2,000 times for the CSO. Glyphosate was found in all samples...
Combined sewer overflows: an environmental source of hormones and wastewater micropollutants
Phillips, P.J.; Chalmers, A.T.; Gray, J.L.; Kolpin, D.W.; Foreman, W.T.; Wall, G.R.
Data were collected at a wastewater treatment plant (WWTP) in Burlington, Vermont, USA, (serving 30,000 people) to assess the relative contribution of CSO (combined sewer overflow) bypass flows and treated wastewater effluent to the load of steroid hormones and other wastewater micropollutants (WMPs) from a WWTP to a lake. Flow-weighted composite samples were collected over a 13 month period at this WWTP from CSO bypass flows or plant influent flows (n = 28) and treated effluent discharges (n = 22). Although CSO discharges represent 10% of the total annual water discharge (CSO plus treated plant effluent discharges) from the WWTP, CSO discharges contribute 40–90% of the annual load for hormones and WMPs with high (>90%) wastewater treatment removal efficiency. By contrast, compounds with low removal efficiencies (hormones and many WMPs in samples from treated discharges can increase with increasing flow due to decreasing removal efficiency.
Elevated circulating leptin levels in arterial hypertension: relationship to arteriovenous overflow and extraction of leptin
DEFF Research Database (Denmark)
Henriksen, Jens Henrik Sahl; Holst, J J; Moller, S
Leptin, a peptide hormone produced mainly in fat cells, appears to be important for the regulation of metabolism, insulin secretion/sensitivity and body weight. Recently, elevated plasma leptin levels have been reported in patients with arterial hypertension. Because a change in circulating leptin...... concentrations in such patients could be caused by altered rates of production or disposal, or both, the aim of the present study was to identify regions of leptin overflow into the bloodstream and of leptin extraction. Patients with arterial hypertension (n=12) and normotensive controls (n=20) were studied...... during catheterization with elective blood sampling from different vascular beds (artery, and renal, hepatic, iliac and cubital veins). Plasma leptin was determined by a radioimmunoassay. Patients with hypertension had significantly elevated levels of circulating leptin (12.8 ng/l, compared with 4.1 ng...
Iceland-Scotland Overflow Water transport variability through the Charlie-Gibbs Fracture Zone and the impact of the North Atlantic Current
Bower, Amy; Furey, Heather
The Charlie-Gibbs Fracture Zone (CGFZ), a deep and wide gap in the Mid-Atlantic Ridge near 52°N, is a gateway between the eastern and western subpolar regions for the Atlantic Meridional Overturning Circulation (AMOC). In 2010-2012, an eight-mooring array of current meters and temperature/salinity sensors was installed across the CGFZ between 500 m and the sea floor to measure the mean transport of westward-flowing Iceland-Scotland Overflow Water (ISOW) and investigate the impact of the eastward-flowing North Atlantic Current (NAC) on ISOW transport variability. The 22 month record mean ISOW transport through the CGFZ, -1.7 ± 0.5 Sv (95% confidence interval), is 30% lower than the previously published estimate based on 13 months of current-only measurements, -2.4 ± 1.2 Sv. The latter mean estimate may have been biased high due to the lack of continuous salinity measurements, although the two estimates are not statistically different due to strong mesoscale variability in both data sets. Empirical Orthogonal Function analysis and maps of satellite-derived absolute dynamic topography show that weak westward ISOW transport events and eastward reversals are caused by northward meanders of the NAC, with its deep-reaching eastward velocities. These results add to growing evidence that a significant fraction of ISOW exits the Iceland Basin by routes other than the CGFZ.
High-Lift OVERFLOW Analysis of the DLR-F11 Wind Tunnel Model
Pulliam, Thomas H.; Sclafani, Anthony J.
In response to the 2nd AIAA CFD High Lift Prediction Workshop, the DLR-F11 wind tunnel model is analyzed using the Reynolds-averaged Navier-Stokes flow solver OVERFLOW. A series of overset grids for a bracket-off landing configuration is constructed and analyzed as part of a general grid refinement study. This high Reynolds number (15.1 million) analysis is done at multiple angles-of-attack to evaluate grid resolution effects at operational lift levels as well as near stall. A quadratic constitutive relation recently added to OVERFLOW for improved solution accuracy is utilized for side-of-body separation issues at low angles-of-attack and outboard wing separation at stall angles. The outboard wing separation occurs when the slat brackets are added to the landing configuration and is a source of discrepancy between the predictions and experimental data. A detailed flow field analysis is performed at low Reynolds number (1.35 million) after pressure tube bundles are added to the bracket-on medium grid system with the intent of better understanding bracket/bundle wake interaction with the wing's boundary layer. Localized grid refinement behind each slat bracket and pressure tube bundle coupled with a time accurate analysis are exercised in an attempt to improve stall prediction capability. The results are inconclusive and suggest the simulation is missing a key element such as boundary layer transition. The computed lift curve is under-predicted through the linear range and over-predicted near stall, and the solution from the most complete configuration analyzed shows outboard wing separation occurring behind slat bracket 6 where the experiment shows it behind bracket 5. These results are consistent with most other participants of this workshop.
Neurturin Protects Against 6-Hydroxydopamine-Induced Reductions in Evoked Dopamine Overflow in Rat Striatum
Cass, Wayne A.; Peters, Laura E.
Neurturin (NTN), a member of the glial cell line-derived neurotrophic factor (GDNF) family, has substantial effects on normal and lesioned nigrostriatal dopamine systems. However, its ability to protect against toxin-induced loss of striatal dopamine release has not been previously reported. The goal of the present study was to determine if NTN could protect against 6-hydroxydopamine (6-OHDA)-induced reductions in striatal dopamine overflow and tissue levels of dopamine, and to compare the effects of NTN with those of GDNF. Male Fischer-344 rats were given a single injection of vehicle, or 5 μg NTN or GDNF, into the right striatum. The following day the animals were given a single injection of 12 μg 6-OHDA into the striatum at the same site where the trophic factor was injected. Microdialysis experiments conducted three weeks later indicated that the 6-OHDA decreased basal levels of dopamine and metabolites in the lesioned striatum compared to the contralateral striatum, and NTN was able to partially protect against the 6-OHDA-induced reductions. Injection of NTN one day prior to 6-OHDA also led to significant protection against loss of both potassium and amphetamine evoked overflow of dopamine. The NTN treatments partially protected against 6-OHDA-induced reductions in striatal tissue levels of dopamine, and completely protected against loss of nigral dopamine content. The protective effects of NTN were similar in magnitude to those of GDNF. These results support that within the experimental parameters used in this study, NTN is as effective as GDNF in protecting against the dopamine-depleting effects of intrastriatal 6-OHDA. PMID:20615442
Desbordando el género y el sexo=Overflowing Gender and Sex
Directory of Open Access Journals (Sweden)
Claudia Truzzoli
Full Text Available Resumen Ni el género ni la sexualidad se dejan encorsetar dentro de unas normas que informan cómo deben ser y actuar hombres y mujeres para ser reconocidos socialmente como normales. Tanto el género como el sexo son susceptibles de desbordamiento de dichos encuadres rígidos, porque tal desbordamiento responde a lo real vivenciado por cualquier hombre o mujer. Las normas son un constructo artificial que no responde a la auténtica identidad genérica y sexual de cada sujeto, que es mucho más compleja que el reduccionismo monolítico que quiere demarcar la diferencia entre masculino y femenino. Dicha separación tan tajante no puede explicar la coexistencia de ambas características en un mismo sujeto ni las pretensiones de los transgéneros de ser considerados con una identidad que desmiente su sexo biológico, ni la angustia de los transexuales convencidos de estar atrapados en un cuerpo equivocado. Abstract Neither gender nor sexuality is allowed to be curtailed within norms that inform how men and women should be and act to be socially recognized as normal. Both gender and sex are susceptible to overflowing of such rigid frames, because such an overflow responds to the real thing experienced by any man or woman. Norms are an artificial construct that does not respond to the authentic generic and sexual identity of each subject, which is much more complex than the monolithic reductionism that wants to demarcate the difference between male and female. Such a clear separation can not explain the coexistence of both characteristics in the same subject nor the claims of transgenders to be considered with an identity that belies their biological sex, nor the anguish of transsexuals convinced to be trapped in a wrong body.
Performance of cylindrical leaf wetness duration sensors in a tropical climate condition Desempenho de sensores cilíndricos para medida da duração do período de molhamento foliar em condições de clima tropical
Directory of Open Access Journals (Sweden)
Eduardo Alvarez Santos
Full Text Available Leaf wetness duration (LWD measurements are required for disease warning in several agricultural systems, since it is an important variable for the diagnose of plant disease epidemiology. The cylindrical sensor is an inexpensive and simple electronic LWD sensor initially designed to measure this variable for onions, however some studies show that it may be helpful for standard measurements in weather stations and also for different crops. Therefore, the objective of this study was to assess their performance under tropical climate conditions, in Brazil, having as standard measurements those obtained by flat plate sensors, which have presented very good performance when compared with visual observations. Before field assessments, all LWD sensors used in our study (flat plates and cylinders were white latex painted and submitted to a heat treatment. Laboratory tests were performed in order to determine the resistance threshold for the sensor to be considered wet and the time response of the sensors to wetness. In the field, all cylindrical sensors were initially deployed horizontally 30-cm above a turfgrass surface in order to assess the variability among them with respect to LWD measurements. The variability among the horizontal cylindrical sensors was reduced by using a specific resistance threshold for each sensor. The mean coefficient of variation (CV of LWD data measured by the cylindrical sensors was 9.7%. After that, the cylindrical sensors were deployed at five different angles: 0º, 15º, 30º, 45º, and 60º. Data of measurements made at these angles were compared with the standard measurement, obtained by flat plate sensors at the same height and installed at 45º. The deployment angle had no systematic effect on LWD measurements for the local tropical conditions, since the correlations between flat plate and elevated cylinder measurements were very high (R² > 0.91, which differed from the results obtained under temperate climatic
Coordinated activation of PTA-ACS and TCA cycles strongly reduces overflow metabolism of acetate in Escherichia coli.
Peebo, Karl; Valgepea, Kaspar; Nahku, Ranno; Riis, Gethe; Oun, Mikk; Adamberg, Kaarel; Vilu, Raivo
Elimination of acetate overflow in aerobic cultivation of Escherichia coli would improve many bioprocesses as acetate accumulation in the growth environment leads to numerous negative effects, e.g. loss of carbon, inhibition of growth, target product synthesis, etc. Despite many years of studies, the mechanism and regulation of acetate overflow are still not completely understood. Therefore, we studied the growth of E. coli K-12 BW25113 and several of its mutant strains affecting acetate-related pathways using the continuous culture method accelerostat (A-stat) at various specific glucose consumption rates with the aim of diminishing acetate overflow. Absolute quantitative exo-metabolome and proteome analyses coupled to metabolic flux analysis enabled us to demonstrate that onset of acetate overflow can be postponed and acetate excretion strongly reduced in E. coli by coordinated activation of phosphotransacetylase-acetyl-CoA synthetase (PTA-ACS) and tricarboxylic acid (TCA) cycles. Fourfold reduction of acetate excretion (2 vs. 8 % from total carbon) at fastest growth compared to wild type was achieved by deleting the genes responsible for inactivation of acetyl-CoA synthetase protein (pka) and TCA cycle regulator arcA. The Δpka ΔarcA strain did not accumulate any other detrimental by-product besides acetate and showed identical μ max and only ~5 % lower biomass yield compared to wild type. We conclude that a fine-tuned coordination between increasing the recycling capabilities of acetate in the PTA-ACS node through a higher concentration of active acetate scavenging Acs protein and downstream metabolism throughput in the TCA cycle is necessary for diminishing overflow metabolism of acetate in E. coli and achieving higher target product production in bioprocesses.
Hand digit control in children: motor overflow in multi-finger pressing force vector space during maximum voluntary force production.
Shim, Jae Kun; Karol, Sohit; Hsu, Jeffrey; de Oliveira, Marcio Alves
The aim of this study was to investigate the contralateral motor overflow in children during single-finger and multi-finger maximum force production tasks. Forty-five right handed children, 5-11 years of age produced maximum isometric pressing force in flexion or extension with single fingers or all four fingers of their right hand. The forces produced by individual fingers of the right and left hands were recorded and analyzed in four-dimensional finger force vector space. The results showed that increases in task (right) hand finger forces were linearly associated with non-task (left) hand finger forces. The ratio of the non-task hand finger force magnitude to the corresponding task hand finger force magnitude, termed motor overflow magnitude (MOM), was greater in extension than flexion. The index finger flexion task showed the smallest MOM values. The similarity between the directions of task hand and non-task hand finger force vectors in four-dimensional finger force vector space, termed motor overflow direction (MOD), was the greatest for index and smallest for little finger tasks. MOM of a four-finger task was greater than the sum of MOMs of single-finger tasks, and this phenomenon was termed motor overflow surplus. Contrary to previous studies, no single-finger or four-finger tasks showed significant changes of MOM or MOD with the age of children. We conclude that the contralateral motor overflow in children during finger maximum force production tasks is dependent upon the task fingers and the magnitude and direction of task finger forces.
Reconfigurable Sensor Monitoring System
Alhorn, Dean C. (Inventor); Dutton, Kenneth R. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)
A reconfigurable sensor monitoring system includes software tunable filters, each of which is programmable to condition one type of analog signal. A processor coupled to the software tunable filters receives each type of analog signal so-conditioned.
A Novel Adaptive Modulation Based on Nondata-Aided Error Vector Magnitude in Non-Line-Of-Sight Condition of Wireless Sensor Network.
Yang, Fan; Zeng, Xiaoping; Mao, Haiwei; Jian, Xin; Tan, Xiaoheng; Du, Derong
The high demand for multimedia applications in environmental monitoring, invasion detection, and disaster aid has led to the rise of wireless sensor network (WSN). With the increase of reliability and diversity of information streams, the higher requirements on throughput and quality of service (QoS) have been put forward in data transmission between two sensor nodes. However, lower spectral efficiency becomes a bottleneck in non-line-of-sight (NLOS) transmission of WSN. This paper proposes a novel nondata-aided error vector magnitude based adaptive modulation (NDA-EVM-AM) to solve the problem. NDA-EVM is considered as a new metric to evaluate the quality of NLOS link for adaptive modulation in WSN. By modeling the NLOS scenario as the η - μ fading channel, a closed-form expression for the NDA-EVM of multilevel quadrature amplitude modulation (MQAM) signals over the η - μ fading channel is derived, and the relationship between SER and NDA-EVM is also formulated. Based on these results, NDA-EVM state machine is designed for adaptation strategy. The algorithmic complexity of NDA-EVM-AM is analyzed and the outage capacity of NDA-EVM-AM in an NLOS scenario is also given. The performances of NDA-EVM-AM are compared by simulation, and the results show that NDA-EVM-AM is an effective technique to be used in the NLOS scenarios of WSN. This technique can accurately reflect the channel variations and efficiently adjust modulation order to better match the channel conditions, hence, obtaining better performance in average spectral efficiency.
Multi-Sensor Data Fusion Identification for Shearer Cutting Conditions Based on Parallel Quasi-Newton Neural Networks and the Dempster-Shafer Theory
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Lei Si
Full Text Available In order to efficiently and accurately identify the cutting condition of a shearer, this paper proposed an intelligent multi-sensor data fusion identification method using the parallel quasi-Newton neural network (PQN-NN and the Dempster-Shafer (DS theory. The vibration acceleration signals and current signal of six cutting conditions were collected from a self-designed experimental system and some special state features were extracted from the intrinsic mode functions (IMFs based on the ensemble empirical mode decomposition (EEMD. In the experiment, three classifiers were trained and tested by the selected features of the measured data, and the DS theory was used to combine the identification results of three single classifiers. Furthermore, some comparisons with other methods were carried out. The experimental results indicate that the proposed method performs with higher detection accuracy and credibility than the competing algorithms. Finally, an industrial application example in the fully mechanized coal mining face was demonstrated to specify the effect of the proposed system.
Multi-Sensor Data Fusion Identification for Shearer Cutting Conditions Based on Parallel Quasi-Newton Neural Networks and the Dempster-Shafer Theory.
Si, Lei; Wang, Zhongbin; Liu, Xinhua; Tan, Chao; Xu, Jing; Zheng, Kehong
In order to efficiently and accurately identify the cutting condition of a shearer, this paper proposed an intelligent multi-sensor data fusion identification method using the parallel quasi-Newton neural network (PQN-NN) and the Dempster-Shafer (DS) theory. The vibration acceleration signals and current signal of six cutting conditions were collected from a self-designed experimental system and some special state features were extracted from the intrinsic mode functions (IMFs) based on the ensemble empirical mode decomposition (EEMD). In the experiment, three classifiers were trained and tested by the selected features of the measured data, and the DS theory was used to combine the identification results of three single classifiers. Furthermore, some comparisons with other methods were carried out. The experimental results indicate that the proposed method performs with higher detection accuracy and credibility than the competing algorithms. Finally, an industrial application example in the fully mechanized coal mining face was demonstrated to specify the effect of the proposed system.
Jugular venous overflow of noradrenaline from the brain: a neurochemical indicator of cerebrovascular sympathetic nerve activity in humans
Mitchell, David A; Lambert, Gavin; Secher, Niels H; Raven, Peter B; van Lieshout, Johannes; Esler, Murray D
A novel neurochemical method was applied for studying the activity of sympathetic nerves in the human cerebral vascular system. The aim was to investigate whether noradrenaline plasma kinetic measurements made with internal jugular venous sampling reflect cerebrovascular sympathetic activity. A database was assembled of fifty-six healthy subjects in whom total body noradrenaline spillover (indicative of whole body sympathetic nervous activity), brain noradrenaline spillover and brain lipophlic noradrenaline metabolite (3,4-dihydroxyphenolglycol (DHPG) and 3-methoxy-4-hydroxyphenylglycol (MHPG)) overflow rates were measured. These measurements were also made following ganglion blockade (trimethaphan, n= 6), central sympathetic inhibition (clonidine, n= 4) and neuronal noradrenaline uptake blockade (desipramine, n= 13) and in a group of patients (n= 9) with pure autonomic failure (PAF). The mean brain noradrenline spillover and brain noradrenaline metabolite overflow in healthy subjects were 12.5 ± 1.8, and 186.4 ± 25 ng min−1, respectively, with unilateral jugular venous sampling for both. Total body noradrenaline spillover was 605.8 ng min−1± 34.4 ng min−1. As expected, trimethaphan infusion lowered brain noradrenaline spillover (P= 0.03), but perhaps surprisingly increased jugular overflow of brain metabolites (P= 0.01). Suppression of sympathetic nervous outflow with clonidine lowered brain noradrenaline spillover (P= 0.004), without changing brain metabolite overflow (P= 0.3). Neuronal noradrenaline uptake block with desipramine lowered the transcranial plasma extraction of tritiated noradrenaline (P= 0.001). The PAF patients had 77% lower brain noradrenaline spillover than healthy recruits (P= 0.06), indicating that in them sympathetic nerve degeneration extended to the cerebral circulation, but metabolites overflow was similar to healthy subjects (P= 0.3). The invariable discordance between noradrenline spillover and noradrenaline metabolite overflow
Overflow Water Pathways in the Subpolar North Atlantic Observed with Deep Floats
Bower, Amy; Furey, Heather; Lozier, Susan
As part of the Overturning in the Subpolar North Atlantic Program (OSNAP), a total of 135 acoustically tracked RAFOS floats have been deployed in the deep boundary currents of the Iceland, Irminger and Labrador Basins, and in the Charlie-Gibbs Fracture Zone, to investigate the pathways of Iceland-Scotland Overflow Water (ISOW) and Denmark Strait Overflow Water (DSOW). Floats were released annually in 2014, 2015 and 2016 at depths between 1800 and 2800 m for two-year missions. The array of sound sources used for tracking was expanded from 10 to 13 moorings in 2016 when it was discovered that wintertime surface roughness was negatively impacting acoustic ranges. The floats from the first setting reveal several examples of persistent , deep coherent eddy motion, including a cyclonic eddy spinning off the tip of Eirik Ridge (southwest of Cape Farewell), a cyclonic eddy in the northeastern Labrador Basin near where anticyclonic Irminger Rings are formed, and an anticyclonic eddy under the North Atlantic Current (NAC) in the central Iceland Basin. A consistent region of boundary-interior exchange was observed near Hamilton Bank on the western boundary of the Labrador Sea. Deep cyclonic recirculation gyres are revealed in all three basins. Floats released in the southward-flowing deep boundary current over the eastern flank of the Reykjanes Ridge show that shallower layers of ISOW peel off to the west and cross the Ridge into the Irminger Basin through various gaps south of 60°N, including the Bight Fracture Zone. These floats tend to turn northward and continue along the slope in the Irminger Basin. Interestingly, floats released at the ISOW level in the CGFZ did not turn into the Irminger Basin as often depicted in deep circulation schematics, but rather drifted west-northwestward toward the Labrador Sea, or eddied around west of the CGFZ and (in some cases) turned southward. This result is consistent with some previous hydrographic and high-resolution model results
Glass, Robert S.; Clarke, Jr., Willis L.; Ciarlo, Dino R.
A corrosion sensor array incorporating individual elements for measuring various elements and ions, such as chloride, sulfide, copper, hydrogen (pH), etc. and elements for evaluating the instantaneous corrosion properties of structural materials. The exact combination and number of elements measured or monitored would depend upon the environmental conditions and materials used which are subject to corrosive effects. Such a corrosion monitoring system embedded in or mounted on a structure exposed to the environment would serve as an early warning system for the onset of severe corrosion problems for the structure, thus providing a safety factor as well as economic factors. The sensor array is accessed to an electronics/computational system, which provides a means for data collection and analysis.
Virtual Sensor Test Instrumentation
Wang, Roy
Virtual Sensor Test Instrumentation is based on the concept of smart sensor technology for testing with intelligence needed to perform sell-diagnosis of health, and to participate in a hierarchy of health determination at sensor, process, and system levels. A virtual sensor test instrumentation consists of five elements: (1) a common sensor interface, (2) microprocessor, (3) wireless interface, (4) signal conditioning and ADC/DAC (analog-to-digital conversion/ digital-to-analog conversion), and (5) onboard EEPROM (electrically erasable programmable read-only memory) for metadata storage and executable software to create powerful, scalable, reconfigurable, and reliable embedded and distributed test instruments. In order to maximize the efficient data conversion through the smart sensor node, plug-and-play functionality is required to interface with traditional sensors to enhance their identity and capabilities for data processing and communications. Virtual sensor test instrumentation can be accessible wirelessly via a Network Capable Application Processor (NCAP) or a Smart Transducer Interlace Module (STIM) that may be managed under real-time rule engines for mission-critical applications. The transducer senses the physical quantity being measured and converts it into an electrical signal. The signal is fed to an A/D converter, and is ready for use by the processor to execute functional transformation based on the sensor characteristics stored in a Transducer Electronic Data Sheet (TEDS). Virtual sensor test instrumentation is built upon an open-system architecture with standardized protocol modules/stacks to interface with industry standards and commonly used software. One major benefit for deploying the virtual sensor test instrumentation is the ability, through a plug-and-play common interface, to convert raw sensor data in either analog or digital form, to an IEEE 1451 standard-based smart sensor, which has instructions to program sensors for a wide variety of
Thresholds in the storm response of a catchment-lake system and the occurrence and magnitude of lake overflows: Implications for flood frequency
Kusumastuti, Dyah I.; Sivapalan, Murugesu; Struthers, Iain; Reynolds, David A.; Murray, Kevin; Turlach, Berwin A.
This model-based study examines the combined effects of catchment and lake thresholds upon the frequency and magnitude of lake-overflow events, and their impacts on flood frequency. A dominant control of lake-overflow events is antecedent storage, which is governed by the climate and by the properties of the contributing catchment. The next major control was shown to be the magnitude of storm depths, and their adequacy to replenish and exceed the lake storage deficit, which are governed by the ratio of catchment to lake areas, AC/AL. When AC/AL is large, lake-overflows can be triggered even at larger antecedent lake storage deficits. This points to the importance of AC/AL as a critical parameter governing the frequency and magnitude of lake-overflow events. As regards the catchment properties, model simulations indicate that fast draining catchments enhance the triggering of lake-overflow events due to the fact that the drainage is rapid and there is the opportunity for faster runoff contributions to combine with direct rainfall on the lakes to exceed antecedent lake storage deficit and overcome the reducing influence of evaporation during inter-storm periods. Slow draining catchments, on the other hand, will not release runoff fast enough to replenish the lake storage deficit before the evaporative effects take hold. The shape of the resulting flood frequency curve captures the dominant lake-overflow generating mechanisms. When the dominant lake overflow generating mechanism is catchment runoff, the shape of flood frequency curve of lake-overflows resembles the shape of the catchment flood frequency curve, including the effects of associated thresholds. On the other hand, when the dominant lake overflow generating mechanism is direct rainfall falling on the lake, the shape of the lake-overflow flood frequency curve exhibits a persistent truncation below a critical return period that is associated with the frequency of flow termination for the given climate in
Occurrence of enrofloxacin in overflows from animal lot and residential sewage lagoons and a receiving-stream
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Abua Ikem
Full Text Available Enrofloxacin (ENRO, a fluoroquinolone, was quantified in overflows from an animal lot and residential sewage lagoons and in a receiving-stream (Gans Creek. The concentrations of ENRO in samples was determined by high-performance liquid chromatography â tandem mass spectrometry. In total, ninety samples including duplicates were analyzed during several monthly sampling campaigns. The samples collected represented the residential sewage lagoon overflow (RLO, animal lot lagoon overflow (ALLO, the combined overflows (RLO and ALLO, and Gans Creek (upstream, midstream and downstream positions. The frequency of detection of ENRO was 90% for RLO and 100% for both ALLO and Gans Creek. The highest concentration of ENRO (0.44 μg/L was found in ALLO sample collected during high precipitation. ENRO levels found in RLO samples ranged from < LOQ to 259 ng/L and the highest value observed also coincided with high flow. The levels of ENRO found in Gans Creek ranged from 17â216 ng/L. A preliminary ecotoxicological assessment was conducted through calculation of the risk quotients (RQs for organisms based on the ratio of the measured environmental concentrations in this study to the predicted-no-effect-concentrations (acute and chronic effect data. From the RQs, high risks were observed for Microcystis aeruginosa (cyanobacteria; RQ = 4.4; Anabaena flosaquae (cyanobacteria; RQ = 1.3; and Lemna minor (aquatic vascular plant; RQ = 2.0. The long-term effects of mixtures of PHCs on Gans Creek watershed are probable. Keywords: Environmental science, Pharmaceutical chemistry, Ecology
Why Do Fast-Growing Bacteria Enter Overflow Metabolism? Testing the Membrane Real Estate Hypothesis.
Szenk, Mariola; Dill, Ken A; de Graff, Adam M R
Bacteria and other cells show a puzzling behavior. At high growth rates, E. coli switch from respiration (which is ATP-efficient) to using fermentation for additional ATP (which is inefficient). This overflow metabolism results in a several-fold decrease in ATP produced per glucose molecule provided as food. By integrating diverse types of experimental data into a simple biophysical model, we give evidence that this onset is the result of the membrane real estate hypothesis: Fast growth drives cells to be bigger, reducing their surface-to-volume ratios. This decreases the membrane area available for respiratory proteins despite growing demand, causing increased crowding. Only when respiratory proteins reach their crowding limit does the cell activate fermentation, since fermentation allows faster ATP production per unit membrane area. Surface limitation thus creates a Pareto trade-off between membrane efficiency and ATP yield that links metabolic choice to the size and shape of a bacterial cell. By exploring the predictions that emerge from this trade-off, we show how consideration of molecular structures, energetics, rates, and equilibria can provide important insight into cellular behavior. Copyright © 2017 Elsevier Inc. All rights reserved.
Modelling of E. coli distribution in coastal areas subjected to combined sewer overflows.
De Marchis, Mauro; Freni, Gabriele; Napoli, Enrico
Rivers, lakes and the sea were the natural receivers of raw urban waste and storm waters for a long time but the low sustainability of such practice, the increase of population and a renewed environmental sensibility increased researcher interest in the analysis and mitigation of the impact of urban waters on receiving water bodies (RWB). In Europe, the integrated modelling of drainage systems and RWB has been promoted as a promising approach for implementing the Water Framework Directive. A particular interest is given to the fate of pathogens and especially of Escherichia coli, in all the cases in which an interaction between population and the RWB is foreseen. The present paper aims to propose an integrated water quality model involving the analysis of several sewer systems (SS) discharging their polluting overflows on the coast in a sensitive marine environment. From a modelling point of view, the proposed application integrated one-dimensional drainage system models with a complex three-dimensional model analysing the propagation in space and time of E. coli in the coastal marine area. The integrated approach was tested in a real case study (the Acicastello bay in Italy) where data were available both for SS model and for RWB propagation model calibration. The analysis shows a good agreement between the model and monitored data. The integrated model was demonstrated to be a valuable tool for investigating the pollutant propagation and to highlight the most impacted areas.
Performance assessment of a vertical flow constructed wetland treating unsettled combined sewer overflow.
Pálfy, T G; Gerodolle, M; Gourdon, R; Meyer, D; Troesch, S; Molle, P
The performance of a vertical flow constructed wetland for combined sewer overflow treatment (CSO CW) has been evaluated. The full-scale site has been monitored for 3 years for major pollutants and for two load events for a range of micropollutants (metals, metalloids and polycyclic aromatic hydrocarbons (PAHs)). Performance were predominantly high (97% for total suspended solids (TSS), 80% for chemical oxygen demand (COD), 72% for NH4-N), even if several loads were extremely voluminous, pushing the filter to its limits. Two different filter materials (a 4:1 mixture of sand and zeolite and natural pozzolana) showed similar treatment performance. Furthermore, environmental factors were correlated with COD removal efficiency. The greatest influencers of COD removal efficiency were the inlet dissolved COD concentrations and the duration and potential evapotranspiration during inter-event periods. Furthermore, sludge was analysed for quality and a sludge depth map was created. The map, and calculating the changes in sludge volume, helped to understand solid accumulation dynamics.
Coupled 1D-2D hydrodynamic inundation model for sewer overflow: Influence of modeling parameters
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Adeniyi Ganiyu Adeogun
Full Text Available This paper presents outcome of our investigation on the influence of modeling parameters on 1D-2D hydrodynamic inundation model for sewer overflow, developed through coupling of an existing 1D sewer network model (SWMM and 2D inundation model (BREZO. The 1D-2D hydrodynamic model was developed for the purpose of examining flood incidence due to surcharged water on overland surface. The investigation was carried out by performing sensitivity analysis on the developed model. For the sensitivity analysis, modeling parameters, such as mesh resolution Digital Elevation Model (DEM resolution and roughness were considered. The outcome of the study shows the model is sensitive to changes in these parameters. The performance of the model is significantly influenced, by the Manning's friction value, the DEM resolution and the area of the triangular mesh. Also, changes in the aforementioned modeling parameters influence the Flood characteristics, such as the inundation extent, the flow depth and the velocity across the model domain.
Combined sewer overflow control with LID based on SWMM: an example in Shanghai, China.
Liao, Z L; Zhang, G Q; Wu, Z H; He, Y; Chen, H
Although low impact development (LID) has been commonly applied across the developed countries for mitigating the negative impacts of combined sewer overflows (CSOs) on urban hydrological environment, it has not been widely used in developing countries yet. In this paper, a typical combined sewer system in an urbanized area of Shanghai, China was used to demonstrate how to design and choose CSO control solutions with LID using stormwater management model. We constructed and simulated three types of CSO control scenarios. Our findings support the notion that LID measures possess favorable capability on CSO reduction. Nevertheless, the green scenarios which are completely comprised by LID measures fail to achieve the maximal effectiveness on CSO reduction, while the gray-green scenarios (LID measure combined with gray measures) achieve it. The unit cost-effectiveness of each type of scenario sorts as: green scenario > gray-green scenario > gray scenario. Actually, as the storage tank is built in the case catchment, a complete application of green scenario is inaccessible here. Through comprehensive evaluation and comparison, the gray-green scenario F which used the combination of storage tank, bio-retention and rain barrels is considered as the most feasible one in this case.
Impact of Combined Sewer Overflow on Wastewater Treatment and Microbiological Quality of Rivers for Recreation
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Franz Mascher
Full Text Available Within the framework of a one-year study the treatment capacity of a municipal wastewater treatment plant (WWTP was evaluated, with regard to fecal indicator bacteria (FIB and to their influence on the recipient. The logarithmic reduction rates for fecal coliforms (FC, Escherichia coli (EC and intestinal enterococci (IE were 2.84, 2.90 and 2.93. In the investigated period of time, the tested treatment plant released 4.3% of the total annual load flow volume as combined sewer overflow (CSO, that is, when the influent into the combined sewer exceeds the capacity of the treatment plant and coarsely cleaned wastewater arrives at the recipient. This CSO discharge increased the number of FIB significantly by 1.2 × 102 MPN/100 mL for EC, and by 1.8 × 101 MPN/100 mL for IE. For the Styrian part of the Mur River (1.6 million inhabitants, a calculation of FIB of all sewage treatment plants estimating the same ratio of CSO (4.3% and a given mean flow rate (QM results in a significant increase of the FIB load in the recipient: 3.8 × 103 MPN/100 mL for EC and 5.8 × 102 MPN/100 mL for IE. On the basis of these values the standards of water quality for recreational purposes cannot be met.
Drag Prediction for the NASA CRM Wing-Body-Tail Using CFL3D and OVERFLOW on an Overset Mesh
Sclafani, Anthony J.; DeHaan, Mark A.; Vassberg, John C.; Rumsey, Christopher L.; Pulliam, Thomas H.
In response to the fourth AIAA CFD Drag Prediction Workshop (DPW-IV), the NASA Common Research Model (CRM) wing-body and wing-body-tail configurations are analyzed using the Reynolds-averaged Navier-Stokes (RANS) flow solvers CFL3D and OVERFLOW. Two families of structured, overset grids are built for DPW-IV. Grid Family 1 (GF1) consists of a coarse (7.2 million), medium (16.9 million), fine (56.5 million), and extra-fine (189.4 million) mesh. Grid Family 2 (GF2) is an extension of the first and includes a superfine (714.2 million) and an ultra-fine (2.4 billion) mesh. The medium grid anchors both families with an established build process for accurate cruise drag prediction studies. This base mesh is coarsened and enhanced to form a set of parametrically equivalent grids that increase in size by a factor of roughly 3.4 from one level to the next denser level. Both CFL3D and OVERFLOW are run on GF1 using a consistent numerical approach. Additional OVERFLOW runs are made to study effects of differencing scheme and turbulence model on GF1 and to obtain results for GF2. All CFD results are post-processed using Richardson extrapolation, and approximate grid-converged values of drag are compared. The medium grid is also used to compute a trimmed drag polar for both codes.
Removal of micropollutants, facultative pathogenic and antibiotic resistant bacteria in a full-scale retention soil filter receiving combined sewer overflow.
Scheurer, Marco; Heß, Stefanie; Lüddeke, Frauke; Sacher, Frank; Güde, Hans; Löffler, Herbert; Gallert, Claudia
Combined sewer systems collect surface runoff as well as wastewater of industrial and domestic origin. During periods of heavy rainfall the capacity of the sewer system is exceeded and the overflow is discharged into receiving waters without any treatment. Consequently, combined sewer overflow (CSO) is considered as a major source of water pollution. This study investigates the effectiveness of a retention soil filter (RSF) for the removal of micropollutants as well as facultative pathogenic and antibiotic resistant bacteria from CSO. The removal of organic group parameters like total organic carbon was excellent and the removal efficiency for micropollutants of the RSF and the wastewater treatment plant (WWTP), which treats wastewater of the same origin during dry and normal weather conditions, was comparable. Compounds of high environmental concern like estrogens or certain pharmaceuticals, e.g. diclofenac, were completely eliminated or removed to a high degree during RSF passage. RSF treatment also reduced the number of E. coli, enterococci and staphylococci by 2.7, 2.2 and 2.4 log-units (median values), respectively. Obviously, some Staphylococcus species can better adapt to the conditions of the RSF than others as a shift of the abundance of the different species was observed when comparing the diversity of staphylococci obtained from the RSF influent and effluent. RSF treatment also decreased the absolute number of antibiotic resistant bacteria. The percentage of antibiotic resistant E. coli and staphylococci isolates also decreased during passage of the RSF, whereas the percentage of resistant enterococci did not change. For E. coli ampicillin and for enterococci and staphylococci erythromycin determined the antibiotic resistance level. The results demonstrate that RSFs can be considered as an adequate treatment option for CSO. The performance for the removal of micropollutants is comparable with a medium sized WWTP with conventional activated sludge
Evaluation of software sensors for on-line estimation of culture conditions in an Escherichia coli cultivation expressing a recombinant protein.
Warth, Benedikt; Rajkai, György; Mandenius, Carl-Fredrik
Software sensors for monitoring and on-line estimation of critical bioprocess variables have mainly been used with standard bioreactor sensors, such as electrodes and gas analyzers, where algorithms in the software model have generated the desired state variables. In this article we propose that other on-line instruments, such as NIR probes and on-line HPLC, should be used to make more reliable and flexible software sensors. Five software sensor architectures were compared and evaluated: (1) biomass concentration from an on-line NIR probe, (2) biomass concentration from titrant addition, (3) specific growth rate from titrant addition, (4) specific growth rate from the NIR probe, and (5) specific substrate uptake rate and by-product rate from on-line HPLC and NIR probe signals. The software sensors were demonstrated on an Escherichia coli cultivation expressing a recombinant protein, green fluorescent protein (GFP), but the results could be extrapolated to other production organisms and product proteins. We conclude that well-maintained on-line instrumentation (hardware sensors) can increase the potential of software sensors. This would also strongly support the intentions with process analytical technology and quality-by-design concepts. 2010 Elsevier B.V. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Thomas, Ken D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Quinn, Edward L. [Technology Resources, Dana Point, CA (United States); Mauck, Jerry L. [Technology Resources, Dana Point, CA (United States); Bockhorst, Richard M. [Technology Resources, Dana Point, CA (United States)
The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy and reliability. This paper, which refers to a final report issued in 2013, demonstrates these benefits in direct comparisons of digital and analog sensor applications. Improved accuracy results from the superior operating characteristics of digital sensors. These include improvements in sensor accuracy and drift and other related parameters which reduce total loop uncertainty and thereby increase safety and operating margins. An example instrument loop uncertainty calculation for a pressure sensor application is presented to illustrate these improvements. This is a side-by-side comparison of the instrument loop uncertainty for both an analog and a digital sensor in the same pressure measurement application. Similarly, improved sensor reliability is illustrated with a sample calculation for determining the probability of failure on demand, an industry standard reliability measure. This looks at equivalent analog and digital temperature sensors to draw the comparison. The results confirm substantial reliability improvement with the digital sensor, due in large part to ability to continuously monitor the health of a digital sensor such that problems can be immediately identified and corrected. This greatly reduces the likelihood of a latent failure condition of the sensor at the time of a design basis event. Notwithstanding the benefits of digital sensors, there are certain qualification issues that are inherent with digital technology and these are described in the report. One major qualification impediment for digital sensor implementation is software common cause failure (SCCF).
Performance of the OVERFLOW-MLP and LAURA-MLP CFD Codes on the NASA Ames 512 CPU Origin System
Taft, James R.
The shared memory Multi-Level Parallelism (MLP) technique, developed last year at NASA Ames has been very successful in dramatically improving the performance of important NASA CFD codes. This new and very simple parallel programming technique was first inserted into the OVERFLOW production CFD code in FY 1998. The OVERFLOW-MLP code's parallel performance scaled linearly to 256 CPUs on the NASA Ames 256 CPU Origin 2000 system (steger). Overall performance exceeded 20.1 GFLOP/s, or about 4.5x the performance of a dedicated 16 CPU C90 system. All of this was achieved without any major modification to the original vector based code. The OVERFLOW-MLP code is now in production on the inhouse Origin systems as well as being used offsite at commercial aerospace companies. Partially as a result of this work, NASA Ames has purchased a new 512 CPU Origin 2000 system to further test the limits of parallel performance for NASA codes of interest. This paper presents the performance obtained from the latest optimization efforts on this machine for the LAURA-MLP and OVERFLOW-MLP codes. The Langley Aerothermodynamics Upwind Relaxation Algorithm (LAURA) code is a key simulation tool in the development of the next generation shuttle, interplanetary reentry vehicles, and nearly all "X" plane development. This code sustains about 4-5 GFLOP/s on a dedicated 16 CPU C90. At this rate, expected workloads would require over 100 C90 CPU years of computing over the next few calendar years. It is not feasible to expect that this would be affordable or available to the user community. Dramatic performance gains on cheaper systems are needed. This code is expected to be perhaps the largest consumer of NASA Ames compute cycles per run in the coming year.The OVERFLOW CFD code is extensively used in the government and commercial aerospace communities to evaluate new aircraft designs. It is one of the largest consumers of NASA supercomputing cycles and large simulations of highly resolved full
Atomic Resolution of Calcium and Oxygen Sublattices of Calcite in Ambient Conditions by Atomic Force Microscopy Using qPlus Sensors with Sapphire Tips.
Wastl, Daniel S; Judmann, Michael; Weymouth, Alfred J; Giessibl, Franz J
Characterization and imaging at the atomic scale with atomic force microscopy in biocompatible environments is an ongoing challenge. We demonstrate atomically resolved imaging of the calcite (101̅4) surface plane using stiff quartz cantilevers ("qPlus sensors", stiffness k = 1280 N/m) equipped with sapphire tips in ambient conditions without any surface preparation. With 10 atoms in one surface unit cell, calcite has a highly complex surface structure comprising three different chemical elements (Ca, C, and O). We obtain true atomic resolution of calcite in air at relative humidity ranging from 20% to 40%, imaging atomic steps and single atomic defects. We observe a great durability of sapphire tips with their Mohs hardness of 9, only one step below diamond. Depending on the state of the sapphire tip, we resolve either the calcium or the oxygen sublattice. We determine the tip termination by comparing the experimental images with simulations and discuss the possibility of chemical tip identification in air. The main challenges for imaging arise from the presence of water layers, which form on almost all surfaces and have the potential to dissolve the crystal surface. Frequency shift versus distance spectra show the presence of at least three ordered hydration layers. The measured height of the first hydration layer corresponds well to X-ray diffraction data and molecular dynamic simulations, namely, ∼220 pm. For the following hydration layers we measure ∼380 pm for the second and third layer, ending up in a total hydration layer thickness of at least 1 nm. Understanding the influence of water layers and their structure is important for surface segregation, surface reactions including reconstructions, healing of defects, and corrosion.
Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment
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I. Andrés-Doménech
Full Text Available Since Water Framework Directive (WFD was passed in year 2000, the conservation of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs from urban drainage networks, the WFD implies that we cannot accept CSOs because of their intrinsic features, but they must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, urban system and the receiving water body must be jointly analysed to evaluate the environmental impact generated on the latter. In this context, a coupled scheme is presented in this paper to assess the CSOs impact on a river system in Torrelavega (Spain. First, a urban model is developed to statistically characterise the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (biochemical oxygen demand, BOD, and total ammonium, NH4+, within the river just after the spills.
Observed and modeled pathways of the Iceland Scotland Overflow Water in the eastern North Atlantic
Zou, Sijia; Lozier, Susan; Zenk, Walter; Bower, Amy; Johns, William
The spreading of Iceland Scotland Overflow Water (ISOW) in the eastern North Atlantic has largely been studied in an Eulerian frame using numerical models or with observations limited to a few locations. No study to date has provided a comprehensive description of the ISOW spreading pathways from both Eulerian and Lagrangian perspectives. In this paper, we use a combination of previously unreported current meter data, hydrographic data, RAFOS float data, and a high resolution (1/12°) numerical ocean model to study the spreading pathways of ISOW from both of these perspectives. We identify three ISOW transport cores in the central Iceland Basin (∼59°N), with the major core along the eastern boundary of the Reykjanes Ridge (RR) and the other two in the basin interior. Based on trajectories of observed and/or numerical floats seeded along 59°N, we also describe the ISOW spreading pathways and quantify their relative importance. Within 10 years, 7-11% of ISOW from 59°N escapes into the Irminger Sea via gaps in the RR north of the Charlie Gibbs Fracture Zone (CGFZ); the water that moves through these gaps principally originates from the shallower ISOW layer along the RR eastern boundary. 10-13% travels further southward until the CGFZ, where it crosses westward into the western subpolar gyre. 18-21% of ISOW spreads southward along the eastern flank of the Mid-Atlantic Ridge into the Western European Basin (WEB). Most of the remaining water stays in the Iceland Basin over the 10-year period. A model-based investigation provides a first look at the temporal variability of these ISOW pathways. We find that the fraction of southward water exported into the WEB is anti-correlated with the export through the CGFZ, a result assumed to reflect these pathways' interactions with the North Atlantic Current in magnitude and/or position shift.
The exometabolome of Clostridium thermocellum reveals overflow metabolism at high cellulose loading.
Holwerda, Evert K; Thorne, Philip G; Olson, Daniel G; Amador-Noguez, Daniel; Engle, Nancy L; Tschaplinski, Timothy J; van Dijken, Johannes P; Lynd, Lee R
Clostridium thermocellum is a model thermophilic organism for the production of biofuels from lignocellulosic substrates. The majority of publications studying the physiology of this organism use substrate concentrations of ≤10 g/L. However, industrially relevant concentrations of substrate start at 100 g/L carbohydrate, which corresponds to approximately 150 g/L solids. To gain insight into the physiology of fermentation of high substrate concentrations, we studied the growth on, and utilization of high concentrations of crystalline cellulose varying from 50 to 100 g/L by C. thermocellum. Using a defined medium, batch cultures of C. thermocellum achieved 93% conversion of cellulose (Avicel) initially present at 100 g/L. The maximum rate of substrate utilization increased with increasing substrate loading. During fermentation of 100 g/L cellulose, growth ceased when about half of the substrate had been solubilized. However, fermentation continued in an uncoupled mode until substrate utilization was almost complete. In addition to commonly reported fermentation products, amino acids - predominantly L-valine and L-alanine - were secreted at concentrations up to 7.5 g/L. Uncoupled metabolism was also accompanied by products not documented previously for C. thermocellum, including isobutanol, meso- and RR/SS-2,3-butanediol and trace amounts of 3-methyl-1-butanol, 2-methyl-1-butanol and 1-propanol. We hypothesize that C. thermocellum uses overflow metabolism to balance its metabolism around the pyruvate node in glycolysis. C. thermocellum is able to utilize industrially relevant concentrations of cellulose, up to 93 g/L. We report here one of the highest degrees of crystalline cellulose utilization observed thus far for a pure culture of C. thermocellum, the highest maximum substrate utilization rate and the highest amount of isobutanol produced by a wild-type organism.
Energy Technology Data Exchange (ETDEWEB)
Valsecchi, Francesca; Rasio, Frederic A. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), and Northwestern University, Department of Physics and Astronomy, Evanston, IL 60208 (United States); Rappaport, Saul [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Marchant, Pablo [Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hgel 71, D-53121 Bonn (Germany); Rogers, Leslie A., E-mail: email@example.com, E-mail: email@example.com, E-mail: email@example.com, E-mail: firstname.lastname@example.com, E-mail: email@example.com [Department of Astronomy and Department of Geophysics and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)
Many exoplanets have now been detected in orbits with ultra-short periods very close to the Roche limit. Building upon our previous work, we study the possibility that mass loss through Roche lobe overflow (RLO) may affect the evolution of these planets, and could possibly transform a hot Jupiter into a lower-mass planet (hot Neptune or super-Earth). We focus here on systems in which the mass loss occurs slowly ("stable mass transfer" in the language of binary star evolution) and we compute their evolution in detail with the binary evolution code Modules for Experiments in Stellar Astrophysics. We include the effects of tides, RLO, irradiation, and photo-evaporation (PE) of the planet, as well as the stellar wind and magnetic braking. Our calculations all start with a hot Jupiter close to its Roche limit, in orbit around a Sun-like star. The initial orbital decay and onset of RLO are driven by tidal dissipation in the star. We confirm that such a system can indeed evolve to produce lower-mass planets in orbits of a few days. The RLO phase eventually ends and, depending on the details of the mass transfer and on the planetary core mass, the orbital period can remain around a few days for several Gyr. The remnant planets have rocky cores and some amount of envelope material, which is slowly removed via PE at a nearly constant orbital period; these have properties resembling many of the observed super-Earths and sub-Neptunes. For these remnant planets, we also predict an anti-correlation between mass and orbital period; very low-mass planets (M{sub pl} ≲ 5 M{sub ⊕}) in ultra-short periods (P{sub orb} < 1 day) cannot be produced through this type of evolution.
Organic micropollutants discharged by combined sewer overflows - Characterisation of pollutant sources and stormwater-related processes.
Launay, Marie A; Dittmer, Ulrich; Steinmetz, Heidrun
To characterise emissions from combined sewer overflows (CSOs) regarding organic micropollutants, a monitoring study was undertaken in an urban catchment in southwest Stuttgart, Germany. The occurrence of 69 organic micropollutants was assessed at one CSO outfall during seven rain events as well as in the sewage network at the influent of the wastewater treatment plant (WWTP) and in the receiving water. Several pollutant groups like pharmaceuticals and personal care products (PPCPs), urban biocides and pesticides, industrial chemicals, organophosphorus flame retardants, plasticisers and polycyclic aromatic hydrocarbons (PAHs) were chosen for analysis. Out of the 69 monitored substances, 60 were detected in CSO discharges. The results of this study show that CSOs represent an important pathway for a wide range of organic micropollutants from wastewater systems to urban receiving waters. For most compounds detected in CSO samples, event mean concentrations varied between the different events in about one order of magnitude range. When comparing CSO concentrations with median wastewater concentrations during dry weather, two main patterns could be observed depending on the source of the pollutant: (i) wastewater is diluted by stormwater; (ii) stormwater is the most important source of a pollutant. Both wastewater and stormwater only play an important role in pollutant concentration for a few compounds. The proportion of stormwater calculated with the conductivity is a suitable indicator for the evaluation of emitted loads of dissolved wastewater pollutants, but not for all compounds. In fact, this study demonstrates that remobilisation of in-sewer deposits contributed from 10% to 65% to emissions of carbamazepine in CSO events. The contribution of stormwater to CSO emitted loads was higher than 90% for all herbicides as well as for PAHs. Regarding the priority substance di(2-ethylhexyl)phthalate (DEHP), this contribution varied between 39% and 85%. The PAH
Late Pliocene Norwegian Greenland Overflow based on benthic stable isotopEs, Mg/Ca, and foraminifera assemblages at ODP Site 984
Weinelt, M.; Bartoli, G.; Erlenkeuser, H.
Increased surface salinity in the Carribean and generally enhanced North Atlantic lower intermediate water ventilation after 4.2 Ma suggest that the closure of the Panama Isthmus favored enhanced heat, salt, and moisture supply to the northern high latitudes and in turn, favored the built up of ice in Greenland and the production of North Atlantic deepwater (Haug &Tiedemann, 1998). The Sediment record of ODP Site 984 (1700m) may serve to test the response and role of the Iceland-Scotland Overflow as key component of NADW over these changing scenarios. Carbonate dissolution cycles at the site were interpreted as a result of corrosive Norwegian Greenland Sea overflow water (Jansen et al., 2000). Though absence of foraminifera over wide parts of glacial stages prevents fully continuous records, high-resolution sampling enabled us to establish benthic stable isotopes records, Mg/Ca temperatures, and faunal assemblages for two time windows, prior (Stages G16-G11) and subsequent (Stages 101-99) to the onset of "Quaternary-style" glaciations at 2.75 Ma. In general, glacial-to-interglacial d18O amplitudes and absolute levels only slightly increase from 0.8‰ (3.8-3‰) in the older window to 1.0‰ (4.2-3.2‰) in the younger window. These amplitudes equal the amplitudes found for planktonic foraminifera at Site 984 and may be attributed to both ice volume and temperature changes. Benthic d13C values suggest a distinct increase in bottom water ventilation from older to younger interglacials (from -0.5 to 1‰). Faunas dominated by Bolivina, Uvigerina, Melonis, and Stilostomella suggest high carbon fluxes during the older interglacials. In the younger window, a fauna dominated by Elphidium suggets low oxygen conditions during glacial stage 100. Ma/Ca concentrations of Uvigerina suggest intermediate water temperatures ranging from 4 to 6°C during interglacial stages 101 and 99. If true, Late Pliocene intermediate water was considerably warmer than today (the Norwegian
Börner, Dirk; Specht, Marcus
This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under
Gait Analysis Using Wearable Sensors
Hutian Feng; Rencheng Zheng; Tao Liu; Weijun Tao
Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phas...
Self-Propagating Worms in Wireless Sensor Networks
DEFF Research Database (Denmark)
Giannetsos, Thanassis; Dimitriou, Tassos; Prasad, Neeli R.
Malicious code is defined as software designed to execute attacks on software systems. This work demonstrates the possibility of executing malware on wireless sensor nodes that are based on the von Neumann architecture. This is achieved by exploiting a buffer overflow vulnerability to smash the c...... the call stack, intrude a remote node over the radio channel and, eventually, completely take control of it. Then we show how the malware can be crafted to become a self-replicating worm that broadcasts itself and propagates over the network hop-by-hop, infecting all the nodes....
Strain features and condition assessment of orthotropic steel deck cable-supported bridges subjected to vehicle loads by using dense FBG strain sensors
Wei, Shiyin; Zhang, Zhaohui; Li, Shunlong; Li, Hui
Strain is a direct indicator of structural safety. Therefore, strain sensors have been used in most structural health monitoring systems for bridges. However, until now, the investigation of strain response has been insufficient. This paper conducts a comprehensive study of the strain features of the U ribs and transverse diaphragm on an orthotropic steel deck and proposes a statistical paradigm for crack detection based on the features of vehicle-induced strain response by using the densely distributed optic fibre Bragg grating (FBG) strain sensors. The local feature of strain under vehicle load is highlighted, which enables the use of measurement data to determine the vehicle loading event and to make a decision regarding the health status of a girder near the strain sensors via technical elimination of the load information. Time–frequency analysis shows that the strain contains three features: the long-term trend item, the short-term trend item, and the instantaneous vehicle-induced item (IVII). The IVII is the wheel-induced strain with a remarkable local feature, and the measured wheel-induced strain is only influenced by the vehicle near the FBG sensor, while other vehicles slightly farther away have no effect on the wheel-induced strain. This causes the local strain series, among the FBG strain sensors in the same transverse locations of different cross-sections, to present similarities in shape to some extent and presents a time delay in successive order along the driving direction. Therefore, the strain series induced by an identical vehicle can be easily tracked and compared by extracting the amplitude and calculating the mutual ratio to eliminate vehicle loading information, leaving the girder information alone. The statistical paradigm for crack detection is finally proposed, and the detection accuracy is then validated by using dense FBG strain sensors on a long-span suspension bridge in China.
Jugular venous overflow of noradrenaline from the brain: a neurochemical indicator of cerebrovascular sympathetic nerve activity in humans
DEFF Research Database (Denmark)
Mitchell, D.A.; Lambert, G.; Secher, Niels H.
)) overflow rates were measured. These measurements were also made following ganglion blockade (trimethaphan, n = 6), central sympathetic inhibition (clonidine, n = 4) and neuronal noradrenaline uptake blockade (desipramine, n = 13) and in a group of patients (n = 9) with pure autonomic failure (PAF...... = 0.3). Neuronal noradrenaline uptake block with desipramine lowered the transcranial plasma extraction of tritiated noradrenaline (P = 0.001). The PAF patients had 77% lower brain noradrenaline spillover than healthy recruits (P = 0.06), indicating that in them sympathetic nerve degeneration extended...
Combined-sewer overflow data and methods of sample collection for selected sites, Detroit, Michigan
Sweat, M.J.; Wolf, J.R.
The discharge of untreated sewage is illegal in Michigan unless permitted under Act 245 due to public health concerns. In October, 1992, the Michigan Department of Natural Resources (MDNR, now the Michigan Department of Environmental Quality) issued a discharge permit to Detroit authorizing discharge from the City's 78 combined-sewer overflows (CSOs), and requiring that a long-term control plan be developed to achieve mandated waterquality standards in receiving waters. The U.S. Environmental Protection Agency (USEPA) issued a national CSO policy in April, 1994, which requires (1) operational improvements of existing systems to minimize discharges and prevent their occurrence in dry weather; (2) publicly operated treatment works (POTW) to characterize the frequency and volume of discharges; and (3) construction of CSO discharge control projects where necessary.In 1993, the Southeast Michigan Council of Governments (SEMCOG) requested assistance from the U.S. Geological Survey (USGS), in cooperation with Detroit Water and Sewerage Department (DWSD) and MDNR, Surface Water Quality Division, to address part of the technical data requirements for requirement 2. The USGS scope of services for this interdisciplinary, multiagency investigation consisted of collection, compilation, and interpretation of the necessary hydrologic data, and documentation of results. In addition to USGS personnel, personnel from DWSD assisted with the field collection of samples and in alerting USGS personnel to CSO effluent discharges.From October 1, 1994 through December 31, 1995, four CSOs discharging to the Detroit River in Detroit, Michigan (figure 1) were monitored to characterize storm-related water quantity and quality. Water velocity, stage, and precipitation were measured continuously and recorded at 5-minute intervals. Water-quality samples were collected at discrete times during storms and analyzed for inorganic and organic pollutants. Discharges were sampled between 30 and 78 times
Calculation of Gas Overflows Through a Face Gap in the Disk Vacuum Pump
Directory of Open Access Journals (Sweden)
N. K. Nikulin
based on the equality of the conductivity of the forward and reverse passages with disks being stationary. The accuracy does not exceed a tolerance. Results and, accordingly, recommendations, given in the article, can be used in designing a flow passage of the disk vacuum pumps, for providing a movement in high-vacuum mechanical pumps, and in calculating the overflows in the flowing passages of a similar pump design.
MEMS climate sensor for crops in greenhouses
DEFF Research Database (Denmark)
Birkelund, Karen; Jensen, Kim Degn; Højlund-Nielsen, Emil
We have developed and fabricated a multi-sensor chip for greenhouse applications and demonstrated the functionality under controlled conditions. The sensor consists of a humidity sensor, temperature sensor and three photodiodes sensitive to blue, red and white light, respectively. The humidity se...
Gait analysis using wearable sensors.
Tao, Weijun; Liu, Tao; Zheng, Rencheng; Feng, Hutian
Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phases, the principles and features of wearable sensors used in gait analysis are provided. The gait analysis methods based on wearable sensors is divided into gait kinematics, gait kinetics, and electromyography. Studies on the current methods are reviewed, and applications in sports, rehabilitation, and clinical diagnosis are summarized separately. With the development of sensor technology and the analysis method, gait analysis using wearable sensors is expected to play an increasingly important role in clinical applications.
Gait Analysis Using Wearable Sensors
Directory of Open Access Journals (Sweden)
Hutian Feng
Full Text Available Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phases, the principles and features of wearable sensors used in gait analysis are provided. The gait analysis methods based on wearable sensors is divided into gait kinematics, gait kinetics, and electromyography. Studies on the current methods are reviewed, and applications in sports, rehabilitation, and clinical diagnosis are summarized separately. With the development of sensor technology and the analysis method, gait analysis using wearable sensors is expected to play an increasingly important role in clinical applications.
Gait Analysis Using Wearable Sensors
Tao, Weijun; Liu, Tao; Zheng, Rencheng; Feng, Hutian
Gait analysis using wearable sensors is an inexpensive, convenient, and efficient manner of providing useful information for multiple health-related applications. As a clinical tool applied in the rehabilitation and diagnosis of medical conditions and sport activities, gait analysis using wearable sensors shows great prospects. The current paper reviews available wearable sensors and ambulatory gait analysis methods based on the various wearable sensors. After an introduction of the gait phases, the principles and features of wearable sensors used in gait analysis are provided. The gait analysis methods based on wearable sensors is divided into gait kinematics, gait kinetics, and electromyography. Studies on the current methods are reviewed, and applications in sports, rehabilitation, and clinical diagnosis are summarized separately. With the development of sensor technology and the analysis method, gait analysis using wearable sensors is expected to play an increasingly important role in clinical applications. PMID:22438763
Directory of Open Access Journals (Sweden)
Jing Jing Yang
Full Text Available Metamaterials have attracted a great deal of attention due to their intriguing properties, as well as the large potential applications for designing functional devices. In this paper, we review the current status of metamaterial sensors, with an emphasis on the evanescent wave amplification and the accompanying local field enhancement characteristics. Examples of the sensors are given to illustrate the principle and the performance of the metamaterial sensor. The paper concludes with an optimistic outlook regarding the future of metamaterial sensor.
Remote Monitoring of the Heart Condition of Athletes by Measuring the Cardiac Action Potential Propagation Time Using a Wireless Sensor Network
Directory of Open Access Journals (Sweden)
Amang Sudarsono
Full Text Available Highly performing athletes are susceptible to cardiac damage of several kinds which may be irreversible. The monitoring of heart rate and ECG waveforms from such subjects by wireless sensor networks has been reported in health and sports care documents. However, a more decisive parameter for instant to instant changes would be the time of Cardiac Action Potential Propagation. This time, which can be between 15-20 ms would shoot suddenly in acute stress in highly performing athletes for short durations. Repeated incidents of such rising values will tend to cause irreversible damage to the heart. We developed the technique of measuring this time and reporting it through a wireless sensor network to monitoring station.
Chatterjea, Supriyo; Thurston, J.; Kininmonth, S.; Havinga, Paul J.M.
This article describes the details of a sensor network that is currently being deployed at the Great Barrier Reef in Australia. The sensor network allows scientists to retrieve sensor data that has a high spatial and temporal resolution. We give an overview of the energy-efficient data aggregation
Börner, Dirk; Kalz, Marco; Specht, Marcus
This software sketch was used in the context of an experiment for the PhD project "Ambient Learning Displays". The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built
Sheth, A.; Henson, C.; Thirunarayan, K.
Sensors are distributed across the globe leading to an avalanche of data about our environment. It is possible today to utilize networks of sensors to detect and identify a multitude of observations, from simple phenomena to complex events and situations. The lack of integration and communication between these networks, however, often isolates important data streams and intensifies the existing problem of too much data and not enough knowledge. With a view to addressing this problem, the Semantic Sensor Web (SSW) [1] proposes that sensor data be annotated with semantic metadata that will both increase interoperability and provide contextual information essential for situational knowledge. Kno.e.sis Center's approach to SSW is an evolutionary one. It adds semantic annotations to the existing standard sensor languages of the Sensor Web Enablement (SWE) defined by OGC. These annotations enhance primarily syntactic XML-based descriptions in OGC's SWE languages with microformats, and W3C's Semantic Web languages- RDF and OWL. In association with semantic annotation and semantic web capabilities including ontologies and rules, SSW supports interoperability, analysis and reasoning over heterogeneous multi-modal sensor data. In this presentation, we will also demonstrate a mashup with support for complex spatio-temporal-thematic queries [2] and semantic analysis that utilize semantic annotations, multiple ontologies and rules. It uses existing services (e.g., GoogleMap) and semantics enhanced SWE's Sensor Observation Service (SOS) over weather and road condition data from various sensors that are part of Ohio's transportation network. Our upcoming plans are to demonstrate end to end (heterogeneous sensor to application) semantics support and study scalability of SSW involving thousands of sensors to about a billion triples. Keywords: Semantic Sensor Web, Spatiotemporal thematic queries, Semantic Web Enablement, Sensor Observation Service [1] Amit Sheth, Cory Henson, Satya
Photoacoustic CO2-Sensor for Automotive Applications
Huber, J; C. Weber; Eberhardt, A.; Wöllenstein, J.
We present a field-tested miniaturized spectroscopic CO2 sensor which is based on the photoacoustic effect. The sensor is developed for automotive applications and considers the requirements for the usage in vehicles. The sensor measures two measurement ranges simultaneously: The monitoring of the indoor air quality and the detection of possible leakages of the coolant in CO2 air-conditioning systems. The sensor consists of a miniaturized innovative photoacoustic sensor unit with integrated e...
40 CFR 1065.215 - Pressure transducers, temperature sensors, and dewpoint sensors.
... sensors, and dewpoint sensors. 1065.215 Section 1065.215 Protection of Environment ENVIRONMENTAL... Measurement of Engine Parameters and Ambient Conditions § 1065.215 Pressure transducers, temperature sensors, and dewpoint sensors. (a) Application. Use instruments as specified in this section to measure...
Corsi, Carlo
The term "Smart Sensors" refer to sensors which contain both sensing and signal processing capabilities with objectives ranging from simple viewing to sophisticated remote sensing, surveillance, search/track, weapon guidance, robotics, perceptronics and intelligence applications. In a broad sense, they include any sensor systems covering the whole electromagnetic spectrum: this paper deals specifically with a new class of smart sensors in infrared spectral bands whose developments started some years ago, when it was recognized that the rapid advances of "very large scale integration" (VLSI) processor technology and mosaic infrared detector array technology could be combined to develop new generations of infrared smart sensor systems with much improved performance. So, sophisticated signal processing operations have been developed for these new systems by integrating microcomputers and other VLSI signal processors within or next to the sensor arrays on the same focal plane avoiding complex computing located far away from the sensors. Recently this approach is achieving higher goals by a new and revolutionary sensors concept which introduce inside the sensor some of the basic function of living eyes, such as dynamic stare, dishomogenity compensation, spatial and temporal filtering. New objectives and requirements of these new focal plane processors are presented for this type of new infrared smart sensor systems. This paper is concerned with the processing techniques for only the front end of the focal plane processing, namely, the enhancement of target-to-noise ratio by background clutter suppression and the improvement in target detection by "smart" and pattern correlation threshold.
Balancing extensive ambition and a context overflowing with opportunities and demands: A grounded theory on stress and recovery among highly educated working young women entering male-dominated occupational areas
Directory of Open Access Journals (Sweden)
Jesper Löve
Full Text Available Several factors underline the issue of stress-related health among young highly educated women. Major societal changes might provide more new challenges with considerably changed and expanded roles than were expected by earlier generations, especially among women. The quantity of young women with higher education has also increased threefold in Sweden in less than two decades and there are a growing number of young women that hereby break with traditional gender positions and enter new occupational areas traditionally dominated by men. The research questions in the present study were: "What is the main concern, regarding stress and recovery, among young highly educated working women breaking with traditional gender positions and entering male-dominated occupational areas?" and "How do they handle this concern?" We conducted open-ended interviews with 20 informants, aged 23–29 years. The results showed that the synergy between highly ambitious individuals and a context overflowing with opportunities and demands ended up in the informants' constantly striving to find a balance in daily life (main concern. This concern refers to the respondents experiencing a constant overload of ambiguity and that they easily became entangled in a loop of stress and dysfunctional coping behavior, threatening the balance between stress and sufficient recovery. In order to handle this concern, the respondents used different strategies in balancing extensive ambition and a context overflowing with opportunities and demands (core category. This preliminary theoretical model deepens our understanding of how the increasing numbers of highly educated young women face complex living conditions endangering their possibility of maintaining health and work ability.
ICUD-0530 Scenario based risk assessment of the dispersion of E-coli from combined sewer overflow to a fresh-water lake
DEFF Research Database (Denmark)
Rasmussen, Michael Robdrup; Thorndahl, Søren Liedtke; Nielsen, Jesper Ellerbæk
A scenario based risk assessment method is used to evaluate how combined sewer overflow (CSO) affects a nearby bathing beach in Skanderborg, Denmark. The method combines an urban drainage model with a 3D CFD model to pre-simulate 60 different scenarios, used for assessing the risk of poor bathing...
1 The effects of alterations in mean arterial blood pressure (MAP), as induced by vasoactive drugs, on heart rate (HR), basal noradrenaline concentration and electrically evoked noradrenaline overflow and on blood flow in the portal vein of freely moving rats, were investigated. 2 By infusion of
Modelling the impact of soakaway retrofits on combined sewage overflows in a 3km2 urban catchment in Copenhagen, Denmark
DEFF Research Database (Denmark)
Roldin, Maria Kerstin; Fryd, Ole; Jeppesen, Jan
Stormwater infiltration measures such as soakaways are expected to be part of future urban drainage systems. However, few studies exist on the effect of extensive stormwater infiltration through soakaways on the overall urban water system, including sewers and groundwater, at city catchment scale...... are that groundwater constraints are important to consider when evaluating the potential of infiltration-based stormwater management, and that it is important to include the hydraulic coupling between soakaways and sewers in models if soakaways are expected to give overflow to the sewers........ In particular such estimates have not been made in real urban settings with multiple physical and structural constraints. This paper presents a methodology for conducting such an analysis, and provides quantitative estimates of the effects on the urban water flows. Using an interdisciplinary, three...
To what extent does variability of historical rainfall series influence extreme event statistics of sewer system surcharge and overflows?
DEFF Research Database (Denmark)
Schaarup-Jensen, Kjeld; Rasmussen, Michael R.; Thorndahl, Søren
In urban drainage modelling long term extreme statistics has become an important basis for decision-making e.g. in connection with renovation projects. Therefore it is of great importance to minimize the uncertainties concerning long term prediction of maximum water levels and combined sewer...... overflow (CSO) in drainage systems. These uncertainties originate from large uncertainties regarding rainfall inputs, parameters, and assessment of return periods. This paper investigates how the choice of rainfall time series influences the extreme events statistics of max water levels in manholes and CSO...... volumes. Traditionally it is rarely to dispose of long term rainfall time series from a local catchment rain gauge. In the present case study this is actually the case. 2 rainfall gauges have recorded events for approximately 9 years at 2 locations within the catchment. Beside these 2 gauges another 7...
To what extent does variability of historical rainfall series influence extreme event statistics of sewer system surcharge and overflows?
DEFF Research Database (Denmark)
Schaarup-Jensen, Kjeld; Rasmussen, Michael R.; Thorndahl, Søren
In urban drainage modeling long term extreme statistics has become an important basis for decision-making e.g. in connection with renovation projects. Therefore it is of great importance to minimize the uncertainties concerning long term prediction of maximum water levels and combined sewer...... overflow (CSO) in drainage systems. These uncertainties originate from large uncertainties regarding rainfall inputs, parameters, and assessment of return periods. This paper investigates how the choice of rainfall time series influences the extreme events statistics of max water levels in manholes and CSO...... volumes. Traditionally it is rarely to dispose of long term rainfall time series from a local catchment rain gauge. In the present case study this is actually the case. 2 rainfall gauges have recorded events for approximately 9 years at 2 locations within the catchment. Beside these 2 gauges another 7...
Thresholds in the storm response of a lake chain system and the occurrence and magnitude of lake overflows: Implications for flood frequency
Kusumastuti, Dyah I.; Sivapalan, Murugesu; Struthers, Iain; Reynolds, David A.
The aim of this paper is to illustrate the effects of spatial organization of lake chains and associated storage thresholds upon lake-overflow behaviour, and specifically their impact upon large scale flow connectivity and the flood frequency of lake overflows. The analysis was carried out with the use of a multiple bucket model of the lake chain system, consisting of a network of both lakes and associated catchment areas, which explicitly incorporated within it three storage thresholds: a catchment field capacity threshold that governs catchment subsurface stormflow, a total storage capacity threshold that governs catchment surface runoff, and a lake storage capacity threshold that determines lake overflow. The model is driven by rainfall inputs generated by a stochastic rainfall model that is able to capture rainfall variability at a wide range of time scales. The study is used to gain insights into the process controls of lake-overflow generation, and in particular, to explore the crucial role of factors relating to lake organization, such as the average catchment area to lake area ( AC/ AL) ratio and the distribution of AC/ AL with distance in the downstream direction (increasing or decreasing). The study showed that the average AC/ AL value was the most important factor determining the frequency of occurrence and magnitude of floods from a landscape consisting of lake chains. The larger the average AC/ AL value the more runoff is generated from catchments thus increasing both the occurrence and magnitude of lake overflows. In this case the flood frequency curve reflects that of the catchment area, and lake organization does not play an important role. When AC/ AL is small the landscape is lake dominated, the spatial organization of lakes has a significant impact on lake connectivity, and consequently on flood frequency. One of the aspects of lake organization that may have a significant influence on lake connectivity is the spatial distribution of AC/ AL from
Sanitary Sewer Overflows and Emergency Room Visits for Gastrointestinal Illness: Analysis of Massachusetts Data, 2006-2007.
Jagai, Jyotsna S; DeFlorio-Barker, Stephanie; Lin, Cynthia J; Hilborn, Elizabeth D; Wade, Timothy J
Sanitary sewer overflows (SSOs) occur when untreated sewage is discharged into water sources before reaching the treatment facility, potentially contaminating the water source with gastrointestinal pathogens. The objective of this paper is to assess associations between SSO events and rates of gastrointestinal (GI) illness in Massachusetts. A case-crossover study design was used to investigate association between SSO events and emergency room (ER) visits with a primary diagnosis of gastrointestinal (GI) illness in Massachusetts for 2006-2007. ER visits for GI were considered exposed if an SSO event occurred in the county of residence within three hazard periods, 0-4 d, 5-9 d, or 10-14 d, before the visit. A time-stratified bidirectional design was used to select control days for each ER visit on the same day of the week during the same month. Fixed effect logistic regression models were used to estimate the risk of ER visits following the SSO event. During the study period, there were 270 SSO events for northeastern Massachusetts and 66,460 ER admissions with GI illness listed as the primary diagnostic code. The overall odds ratio (OR) for ER visits for GI illness was 1.09 [95% confidence interval (CI): 1.03, 1.16] in the 10-14 d period following an SSO event, with positive ORs for all age groups and for three of the four counties. The 0-4 d and 5-9 d periods following an SSO event were not associated with ER visits for GI illness overall, and associations by county or age were inconsistent. We demonstrated an association between SSO events and ER visits for GI illness using a case-crossover study design. In light of the aging water infrastructure in the United States and the expected increase in heavy rainfall events, our findings suggest a potential health impact associated with sewage overflows. https://doi.org/10.1289/EHP2048.
Analysis of the French insurance market exposure to floods: a stochastic model combining river overflow and surface runoff
Moncoulon, D.; Labat, D.; Ardon, J.; Leblois, E.; Onfroy, T.; Poulard, C.; Aji, S.; Rémy, A.; Quantin, A.
The analysis of flood exposure at a national scale for the French insurance market must combine the generation of a probabilistic event set of all possible (but which have not yet occurred) flood situations with hazard and damage modeling. In this study, hazard and damage models are calibrated on a 1995-2010 historical event set, both for hazard results (river flow, flooded areas) and loss estimations. Thus, uncertainties in the deterministic estimation of a single event loss are known before simulating a probabilistic event set. To take into account at least 90 % of the insured flood losses, the probabilistic event set must combine the river overflow (small and large catchments) with the surface runoff, due to heavy rainfall, on the slopes of the watershed. Indeed, internal studies of the CCR (Caisse Centrale de Reassurance) claim database have shown that approximately 45 % of the insured flood losses are located inside the floodplains and 45 % outside. Another 10 % is due to sea surge floods and groundwater rise. In this approach, two independent probabilistic methods are combined to create a single flood loss distribution: a generation of fictive river flows based on the historical records of the river gauge network and a generation of fictive rain fields on small catchments, calibrated on the 1958-2010 Météo-France rain database SAFRAN. All the events in the probabilistic event sets are simulated with the deterministic model. This hazard and damage distribution is used to simulate the flood losses at the national scale for an insurance company (Macif) and to generate flood areas associated with hazard return periods. The flood maps concern river overflow and surface water runoff. Validation of these maps is conducted by comparison with the address located claim data on a small catchment (downstream Argens).
Mixing in the stratified interface of the Faroe Bank Channel overflow: The role of transverse circulation and internal waves
Seim, Knut S.; Fer, Ilker
The overflow of cold water across the Faroe Bank Channel sill is a significant volume flux of dense water to the North Atlantic Ocean. Using observations of hydrography, current and microstructure from a 1 week cruise and 2 month long time series from moored instruments, we address the role of transverse circulation and internal waves in mixing in the stratified 100 m thick plume-ambient interface. The streamwise momentum budget is dominated by a balance between the pressure gradient and bottom friction; the entrainment stress is negligible. The transverse momentum budget is in geostrophic balance, and the transverse velocity variability is governed by the internal streamwise pressure gradient. The transverse geostrophic flow in the interfacial layer is opposed by the bottom Ekman transport. The shear associated with the interfacial jet lowers the Richardson number and enhances dissipation rates. Convective overturning events observed on the upslope side suggest a link between the transverse circulation and the vertical mixing on the upper slope. Several independent threads of evidence support the transverse circulation as an important mixing mechanism for the overflow plume. In the ambient, dissipation rates inferred from fine-scale shear and density profile measurements are in good agreement with direct measurements, supporting internal wave breaking as a dominant mechanism for dissipation of turbulent energy. In the interfacial layer, spectral distribution of internal wavefield is energetic. In addition to shear-induced mixing and entrainment in the interfacial layer, internal wave breaking is likely to be important for the dissipation of turbulent energy and should not be ignored.
Luebke, Ryan
A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.
Marrazza, Giovanna
In the last years, great progress has been accomplished in the development of aptamer sensors with different transducers. In order to improve the sensitivity of these biosensors, several methodologies have been employed. In this Special Issue, the state of art and the future trends in the field of aptamer sensors have been explored.
Kossives, Dean P.
A new sensor system, whose functionality is not reliant on mass spectrometric or ionization methods, is combined with a substrate technology which allows for separately optimized control circuits and standardized advanced sensors in a simple packaging methodology to foster an entirely new generation of modular optical sensors. These sensors will be based on biologic and chromic compounds. The compounds will utilize reversible reaction chemistry to enable self cleaning. The detector's operation is based on simple changes in absorbance, reflectance, color, or other optical properties. The time to saturation of the sensor will determine the relative concentration in the air. A detection scheme based on these properties will function in high background levels and also be able to pick up low level concentrations as well.
Directory of Open Access Journals (Sweden)
Joseph Irudayaraj
Full Text Available The development of sensors for detecting foodborne pathogens has been motivated by the need to produce safe foods and to provide better healthcare. However, in the more recent times, these needs have been expanded to encompass issues relating to biosecurity, detection of plant and soil pathogens, microbial communities, and the environment. The range of technologies that currently flood the sensor market encompass PCR and microarray-based methods, an assortment of optical sensors (including bioluminescence and fluorescence, in addition to biosensor-based approaches that include piezoelectric, potentiometric, amperometric, and conductometric sensors to name a few. More recently, nanosensors have come into limelight, as a more sensitive and portable alternative, with some commercial success. However, key issues affecting the sensor community is the lack of standardization of the testing protocols and portability, among other desirable elements, which include timeliness, cost-effectiveness, user-friendliness, sensitivity and specificity. [...
JSC Wireless Sensor Network Update
Wagner, Robert
Sensor nodes composed of three basic components... radio module: COTS radio module implementing standardized WSN protocol; treated as WSN modem by main board main board: contains application processor (TI MSP430 microcontroller), memory, power supply; responsible for sensor data acquisition, pre-processing, and task scheduling; re-used in every application with growing library of embedded C code sensor card: contains application-specific sensors, data conditioning hardware, and any advanced hardware not built into main board (DSPs, faster A/D, etc.); requires (re-) development for each application.
Garment-Integrated Bend Sensor
Directory of Open Access Journals (Sweden)
Guido Gioberto
Full Text Available Garment-integrated sensors equip clothes with a smart sensing capability, while preserving the comfort of the user. However, this benefit can be to the detriment of sensing accuracy due to the unpredictability of garment movement (which affects sensor positioning and textile folds (which can affect sensor orientation. However, sensors integrated directly into garments or fabric structures can also be used to detect the movement of the garment during wearing. Specifically, a textile bend sensor could be used to sense folds in the garment. We tested a garment-integrated stitched sensor for five types of folds, stitched on five different weights of un-stretchable denim fabric and analyzed the effects of fold complexity and fabric stiffness, under un-insulated and insulated conditions. Results show that insulation improves the linearity and repeatability of the sensor response, particularly for higher fold complexity. Stiffer fabrics show greater sensitivity, but less linearity. Sensor response amplitude is larger for more complex fold geometries. The utility of a linear bending response (insulated and a binary shorting response (un-insulated is discussed. Overall, the sensor exhibits excellent repeatability and accuracy, particularly for a fiber-based, textile-integrated sensor.
Miniaturized multi-sensor for aquatic studies
DEFF Research Database (Denmark)
Birkelund, Karen; Hyldgård, Anders; Mortensen, Dennis
We have developed and fabricated a multi-sensor chip for fisheries' research and demonstrated the functionality under controlled conditions. The outer dimensions of the sensor chip are 3.0 × 7.4 × 0.8 mm3 and both sides of the chip are utilized for sensors. Hereby a more compact chip is achieved ...
Sharapov, Valeriy
This book presents the latest and complete information about various types of piezosensors. A sensor is a converter of the measured physical size to an electric signal. Piezoelectric transducers and sensors are based on piezoelectric effects. They have proven to be versatile tools for the measurement of various processes. They are used for quality assurance, process control and for research and development in many different industries. In each area of application specific requirements to the parameters of transducers and sensors are developed. This book presents the fundamentals, technical des
Poole-frenkel piezoconductive element and sensor
Habermehl, Scott D.
A new class of highly sensitive piezoconductive strain sensor elements and sensors has been invented. The new elements function under conditions such that electrical conductivity is dominated by Poole-Frenkel transport. A substantial piezoconductive effect appears in this regime, allowing the new sensors to exhibit sensitivity to applied strain as much as two orders of magnitude in excess of prior art sensors based on doped silicon.
Fiber optical sensors for aircraft applications
Pechstedt, Ralf D.
In this paper selected fiber optical point sensors that are of potential interest for deployment in aircraft are discussed. The operating principles together with recent measurement results are described. Examples include a high-temperature combined pressure and temperature sensor for engine health, hydraulics and landing gear monitoring, an ultra-high sensitive pressure sensor for oil, pneumatic and fluid aero systems applications and a combined acceleration and temperature sensor for condition monitoring of rotating components.
Docket No. 300119 1 of 11 VIBRISSA SENSOR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and used by...REFERENCE TO OTHER PATENT APPLICATIONS [0002] None. BACKGROUND OF THE INVENTION (1) Field of the Invention [0003] The present invention provides a...vibrissa in two dimensions. SUMMARY OF THE INVENTION [0010] Accordingly, it is an object of the present invention to provide a sensor capable of
The influence of ns- and fs-LA plume local conditions on the performance of a combined LIBS/LA-ICP-MS sensor
Energy Technology Data Exchange (ETDEWEB)
LaHaye, Nicole L.; Phillips, Mark C.; Duffin, Andrew M.; Eiden, Gregory C.; Harilal, Sivanandan S.
Both laser-induced breakdown spectroscopy (LIBS) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) are well-established analytical techniques with their own unique advantages and disadvantages. The combination of the two analytical methods is a very promising way to overcome the challenges faced by each method individually. We made a comprehensive comparison of local plasma conditions between nanosecond (ns) and femtosecond (fs) laser ablation (LA) sources in a combined LIBS and LA-ICP-MS system. The optical emission spectra and ICP-MS signal were recorded simultaneously for both ns- and fs-LA and figures of merit of the system were analyzed. Characterization of the plasma was conducted by evaluating temperature and density of the plume under various irradiation conditions using optical emission spectroscopy, and correlations to ns- and fs-LIBS and LA-ICP-MS signal were made. The present study is very useful for providing conditions for a multimodal system as well as giving insight into how laser ablation plume parameters are related to LA-ICP-MS and LIBS results for both ns- and fs-LA.
Constructed Wetlands for Treatment of Combined Sewer Overflow in the US: A Review of Design Challenges and Application Status
Directory of Open Access Journals (Sweden)
Wendong Tao
Full Text Available As combined sewer systems and centralized wastewater treatment facilities age, many communities in the world are challenged by management of combined sewer overflow (CSO. Constructed wetlands are considered to be one of the green infrastructure solutions to CSOs in the US. Despite the wide application of constructed wetlands to different types of wastewaters, the stochastic and intermittent nature of CSO presents challenges for design and performance assessment of constructed wetlands. This paper reviews the application status of CSO constructed wetlands in the US, assesses the benefits of CSO constructed wetlands, identifies challenges to designing CSO constructed wetlands, and proposes design considerations. This review finds that constructed wetlands are effective in CSO treatment and relatively less expensive to build than comparable grey infrastructure. Constructed wetlands not only remove pollutants, but also mitigate the event-associated flow regime. The design challenges include incorporating considerations of green infrastructure into permit requirements, determining design capacity for highly variable flows, requiring pretreatment, and needing adaptive design and intensive monitoring. Simultaneous monitoring of flow rate and water quality at both the inflow and outflow of CSO constructed wetlands is required for performance assessment and needed to support design, but is rarely available.
Assessment of a novel overflow-type electrochemical membrane bioreactor (EMBR) for wastewater treatment, energy recovery and membrane fouling mitigation.
Zhou, Guowang; Zhou, Yuhong; Zhou, Guoqiang; Lu, Lian; Wan, Xiankai; Shi, Huixiang
A novel overflow-type electrochemical membrane bioreactor (EMBR) without ion exchange membrane, was developed for wastewater treatment and utilized electricity recovered by microbial fuel cell (MFC) for membrane fouling mitigation in membrane bioreactor (MBR). The maximum power density of 629mW/m(3) or 7.18mW/m(2) was obtained. The removal efficiencies of chemical oxygen demand, ammonia nitrogen and total nitrogen under appropriate ranges of hydraulic retention times (16.9-8.5h) were 92.6±5.4%, 96.5±2.8% and 73.9±9.7%, respectively. Sequencing showed electrochemically active bacteria Lactococcus, Bacillus and Saprospiraceae_uncultured were abundant in the biofilm. Compared with a conventional MBR, five significant effects of the MFC integration on the sludge properties, including particle zeta potential decrease, particle size distribution macroaggregation, soluble microbial products and extracellular polymeric substances reduction and SMPP/SMPC ratio increase, were achieved in this system, leading to membrane fouling mitigation. This system shows great promise for practical wastewater treatment application. Copyright © 2015 Elsevier Ltd. All rights reserved.
Effects of rainfall events on the occurrence and detection efficiency of viruses in river water impacted by combined sewer overflows.
Hata, Akihiko; Katayama, Hiroyuki; Kojima, Keisuke; Sano, Shoichi; Kasuga, Ikuro; Kitajima, Masaaki; Furumai, Hiroaki
Rainfall events can introduce large amount of microbial contaminants including human enteric viruses into surface water by intermittent discharges from combined sewer overflows (CSOs). The present study aimed to investigate the effect of rainfall events on viral loads in surface waters impacted by CSO and the reliability of molecular methods for detection of enteric viruses. The reliability of virus detection in the samples was assessed by using process controls for virus concentration, nucleic acid extraction and reverse transcription (RT)-quantitative PCR (qPCR) steps, which allowed accurate estimation of virus detection efficiencies. Recovery efficiencies of poliovirus in river water samples collected during rainfall events (10%). The log10-transformed virus concentration efficiency was negatively correlated with suspended solid concentration (r(2)=0.86) that increased significantly during rainfall events. Efficiencies of DNA extraction and qPCR steps determined with adenovirus type 5 and a primer sharing control, respectively, were lower in dry weather. However, no clear relationship was observed between organic water quality parameters and efficiencies of these two steps. Observed concentrations of indigenous enteric adenoviruses, GII-noroviruses, enteroviruses, and Aichi viruses increased during rainfall events even though the virus concentration efficiency was presumed to be lower than in dry weather. The present study highlights the importance of using appropriate process controls to evaluate accurately the concentration of water borne enteric viruses in natural waters impacted by wastewater discharge, stormwater, and CSOs. © 2013.
Deep Tunnel for Regulating Combined Sewer Overflow Pollution and Flood Disaster: A Case Study in Guangzhou City, China
Directory of Open Access Journals (Sweden)
Haichun Wu
Full Text Available The DongHaoChong (DHC basin is located in the central city zone of Guangzhou City, China. Owing to the high density of buildings and low quality of the drainage pipe network in the city, diversion of rain and sewage is difficult. Waterlogging occurs frequently and combined sewer overflow (CSO pollution is a serious problem during the rainy season. Therefore, a deep tunnel for the DongHaoChong basin has been planned and its construction is currently underway. An urban rainstorm model for the DongHaoChong basin was developed on the basis of the Storm Water Management Model (SWMM, and both the interception effect of CSO pollution and the degree of mitigation of flood were analyzed. Reasonable scenarios for the deep tunnel in terms of rainstorms with different design recurrence periods were evaluated. From the viewpoints of preventing rainstorm waterlogging disasters and protecting water quality in the region downstream of DongHaoChong River, the river flood control and drainage capacities of the region were improved to a 2-year rainstorm design recurrence period by the construction of the deep tunnel. Furthermore, the main pollutant load of the CSO is expected to be reduced by about 30%–40%.
Coordinated management of combined sewer overflows by means of environmental decision support systems.
Murla, Damian; Gutierrez, Oriol; Martinez, Montse; Suñer, David; Malgrat, Pere; Poch, Manel
During heavy rainfall, the capacity of sewer systems and wastewater treatment plants may be surcharged producing uncontrolled wastewater discharges and a depletion of the environmental quality. Therefore there is a need of advanced management tools to tackle with these complex problems. In this paper an environmental decision support system (EDSS), based on the integration of mathematical modeling and knowledge-based systems, has been developed for the coordinated management of urban wastewater systems (UWS) to control and minimize uncontrolled wastewater spills. Effectiveness of the EDSS has been tested in a specially designed virtual UWS, including two sewers systems, two WWTP and one river subjected to typical Mediterranean rain conditions. Results show that sewer systems, retention tanks and wastewater treatment plants improve their performance under wet weather conditions and that EDSS can be very effective tools to improve the management and prevent the system from possible uncontrolled wastewater discharges. Copyright © 2016 Elsevier B.V. All rights reserved.
Sensors Applications, Volume 2, Sensors in Intelligent Buildings
Gassmann, Oliver; Meixner, Hans
Taken as a whole, this series covers all major fields of application for commercial sensors, as well as their manufacturing techniques and major types. As such the series does not treat bulk sensors, but rather places strong emphasis on microsensors, microsystems and integrated electronic sensor packages. Each of the individual volumes is tailored to the needs and queries of readers from the relevant branch of industry. A comprehensive survey for engineers and scientists on the different sensor types for energy efficiency, security, maintenance management and smart house devices. As such, the text covers air conditioning, large premises control, service and installation monitoring as well as emergency control. It also discusses the strengths and weaknesses in each case, illustrating which sensor is used in which subsystem and why.
Fibre optic humidity sensor designed for highly alkaline environments
K. Bremer; Wollweber, M.; Guenther, S.; Werner, G.; Sun, T.; Grattan, K. T. V.; Roth, B.
This paper presents the design of a sensor packaging for a Fibre Bragg Grating (FBG) based fibre optic humidity sensor. The evaluation of the developed fibre optic sensor was performed under experimental conditions and verified its capability to withstand highly alkaline environments. Therefore, the sensor can be applied to monitor the concrete humidity level and thus to indicate the maintenance of concrete structures.
An azine based sensor for selective detection of Cu2 + ions and its copper complex for sensing of phosphate ions in physiological conditions and in living cells
Tiwari, Karishma; Kumar, Sumit; Kumar, Vipan; Kaur, Jeevanjot; Arora, Saroj; Mahajan, Rakesh Kumar
A simple and cost effective unsymmetrical azine based Schiff base, 5-diethylamino-2-[(2-hydroxy-benzylidene)hydrazonomethyl]-phenol (1) was synthesized which selectively detect Cu2 + ions in the presence of other competitive ions through ;naked eye; in physiological conditions (EtOH-buffer (1:1, v/v, HEPES 10 mM, pH = 7.4)). The presence of Cu2 + induce color change from light yellow green to yellow with the appearance of a new band at 450 nm in UV-Vis spectra of Schiff base 1. The fluorescence of Schiff base 1 (10 μM) was quenched completely in the presence of 2.7 equiv. of Cu2 + ions. Sub-micromolar limit of detection (LOD = 3.4 × 10- 7 M), efficient Stern-Volmer quenching constant (KSV = 1.8 × 105 L mol- 1) and strong binding constant (log Kb = 5.92) has been determined with the help of fluorescence titration profile. Further, 1 - Cu2 + complex was employed for the detection of phosphate ions (PO43 -, HPO42 - and H2PO4-) at micromolar concentrations in EtOH-buffer of pH 7.4 based on fluorescence recovery due to the binding of Cu2 + with phosphate ions. Solubility at low concentration in aqueous medium, longer excitation (406 nm) and emission wavelength (537 nm), and biocompatibility of Schiff base 1 formulates its use in live cell imaging.
Characterization of the cloud conditions at Ny-Ålesund using sensor synergy and representativeness of the observed clouds across Arctic sites
Nomokonova, Tatiana; Ebell, Kerstin; Löhnert, Ulrich; Maturilli, Marion
Clouds are one of the crucial components of the hydrological and energy cycles and thus affecting the global climate. Their special importance in Arctic regions is defined by cloud's influence on the radiation budget. Arctic clouds usually occur at low altitudes and often contain highly concentrated tiny liquid drops. During winter, spring, and autumn periods such clouds tend to conserve the long-wave radiation in the atmosphere and, thus, produce warming of the Arctic climate. In summer though clouds efficiently scatter the solar radiation back to space and, therefore, induce a cooling effect. An accurate characterization of the net effect of clouds on the Arctic climate requires long-term and precise observations. However, only a few measurement sites exist which perform continuous, vertically resolved observations of clouds in the Arctic, e.g. in Alaska, Canada, and Greenland. These sites typically make use of a combination of different ground-based remote sensing instruments, e.g. cloud radar, ceilometer and microwave radiometer in order to characterize clouds. Within the Transregional Collaborative Research Center (TR 172) "Arctic Amplification: Climate Relevant Atmospheric and Surface Processes, and Feedback Mechanisms (AC)3" comprehensive observations of the atmospheric column are performed at the German-French Research Station AWIPEV at Ny-Ålesund, Svalbard. Ny-Ålesund is located in the warmest part of the Arctic where climate is significantly influenced by adiabatic heating from the warm ocean. Thus, measurements at Ny-Ålesund will complement our understanding of cloud formation and development in the Arctic. This particular study is devoted to the characterization of the cloud macro- and microphysical properties at Ny-Ålesund and of the atmospheric conditions, under which these clouds form and develop. To this end, the information of the various instrumentation at the AWIPEV observatory is synergistically analysed: information about the thermodynamic
Multiparametric methane sensor for environmental monitoring
Borecki, M.; Duk, M.; Kociubiński, A.; Korwin-Pawlowski, M. L.
Today, methane sensors find applications mostly in safety alarm installations, gas parameters detection and air pollution classification. Such sensors and sensors elements exists for industry and home use. Under development area of methane sensors application is dedicated to ground gases monitoring. Proper monitoring of soil gases requires reliable and maintenance-free semi-constant and longtime examination at relatively low cost of equipment. The sensors for soil monitoring have to work on soil probe. Therefore, sensor is exposed to environment conditions, as a wide range of temperatures and a full scale of humidity changes, as well as rain, snow and wind, that are not specified for classical methane sensors. Development of such sensor is presented in this paper. The presented sensor construction consists of five commercial non dispersive infra-red (NDIR) methane sensing units, a set of temperature and humidity sensing units, a gas chamber equipped with a micro-fan, automated gas valves and also a microcontroller that controls the measuring procedure. The electronics part of sensor was installed into customized 3D printed housing equipped with self-developed gas valves. The main development of proposed sensor is on the side of experimental evaluation of construction reliability and results of data processing included safety procedures and function for hardware error correction. Redundant methane sensor units are used providing measurement error correction as well as improved measurement accuracy. The humidity and temperature sensors are used for internal compensation of methane measurements as well as for cutting-off the sensor from the environment when the conditions exceed allowable parameters. Results obtained during environment sensing prove that the gas concentration readings are not sensitive to gas chamber vertical or horizontal position. It is important as vertical sensor installation on soil probe is simpler that horizontal one. Data acquired during six
Transport of Iceland-Scotland Overflow waters in the Deep Western Boundary Current along the Reykjanes Ridge
Johns, William; Houk, Adam; Koman, Greg; Zou, Sijia; Lozier, Susan
Since 2014, an array of current meters deployed as part of the OSNAP trans-basin observing system has provided new measurements of the southward flow of Iceland-Scotland Overflow water (ISOW) along the eastern flank of the Reykjanes Ridge in the Iceland Basin. The location of the array, near 58-59°N, captures the ISOW Deep Western Boundary Current at the farthest downstream location in the Iceland Basin before significant amounts of ISOW can flow into the Irminger Basin through deep fractures in the Reykjanes Ridge. The transport of the ISOW DWBC at this location - based on the first two years of OSNAP observations (July 2014 to July 2016) - is 5.8 ± 0.9 Sv for σθ >27.8. Most of this transport is carried in a main branch of the DWBC along the upper ridge crest in depths from 1400-2200 m, while a secondary branch in depths of 2400-2700 m along the lower ridge crest carries about 1 Sv. The branching of the DWBC at this location is consistent with numerical model results and is caused by an upstream topographic plateau at mid-depths along the ridge crest. The T-S properties of the flow and backward trajectories computed from high-resolution FLAME and VIKING models confirm that the flow in both branches is derived from ISOW and its entrainment products. The transport of the ISOW plume varies over a considerable range, from about 2-10 Sv on weekly to monthly time scales (std. dev. = 2.4 Sv); however the mean currents from two individual year-long deployments are very similar and indicate a robust mean flow structure. The observed ISOW transport at this location is larger by almost 2 Sv than previous values obtained (mostly) farther north in the Iceland Basin, suggesting that additional entrainment into the ISOW plume occurs as it approaches the southern tip of the Reykjanes Ridge.
Image processing occupancy sensor
Brackney, Larry J.
A system and method of detecting occupants in a building automation system environment using image based occupancy detection and position determinations. In one example, the system includes an image processing occupancy sensor that detects the number and position of occupants within a space that has controllable building elements such as lighting and ventilation diffusers. Based on the position and location of the occupants, the system can finely control the elements to optimize conditions for the occupants, optimize energy usage, among other advantages.
Optical fibre microwire sensors
Brambilla, G.; Belal, Mohammad; Jung, Y.; Song, Z.; Xu, F.; Newson, T.P.; Richardson, D.J.
This paper reviews sensing applications of optical fibre microwires and nanowires. In addition to the usual benefits of sensors based on optical fibres, these sensors are extremely compact and have fast response speeds. In this review sensors will be grouped in three categories according to their morphology: linear sensors, resonant sensors and tip sensors. While linear and resonant sensors mainly exploit the fraction of power propagating outside the microwire physical boundary, tip sensors t...
A unique zinc-organic framework constructed through in situ ligand synthesis for conversion of CO2 under mild conditions and as a luminescence sensor for Cr2O72-/CrO42.
Song, Tian-Qun; Dong, Jie; Gao, Hong-Ling; Cui, Jian-Zhong; Zhao, Bin
A novel zinc-organic framework, {[Zn3(tza)2(μ2-OH)2(H2O)2]·H2O}n (1) (H2tza = 1H-tetrazolate-5-acetic acid), was synthesized through an in situ generated tetrazole ligand under hydrothermal conditions. In compound 1, tza2- ligands and Zn2+ are interlinked to form 2D layers, which are further pillared through μ2-OH groups to generate a 3D framework. Thermogravimetric analysis and powder X-ray diffraction confirm that 1 has high thermal stability, pH stability and solvent stability. Catalytic studies show that 1 exhibits excellent catalytic ability for the cycloaddition of CO2 with epoxides under 50 °C and 0.1 MPa. Importantly, 1 can be reused at least six times. Furthermore, luminescence investigations indicate that 1 can serve as a recyclable luminescence sensor to efficiently detect Cr2O72-/CrO42-, and the detection limit can reach 10-6 mol L-1 and 4 × 10-6 mol L-1, respectively.
Mee, David K.; Ripley, Edward B.; Nienstedt, Zachary C.; Nienstedt, Alex W.; Howell, Jr., Layton N.
Disclosed is a passive, in-situ pressure sensor. The sensor includes a sensing element having a ferromagnetic metal and a tension inducing mechanism coupled to the ferromagnetic metal. The tension inducing mechanism is operable to change a tensile stress upon the ferromagnetic metal based on a change in pressure in the sensing element. Changes in pressure are detected based on changes in the magnetic switching characteristics of the ferromagnetic metal when subjected to an alternating magnetic field caused by the change in the tensile stress. The sensing element is embeddable in a closed system for detecting pressure changes without the need for any penetrations of the system for power or data acquisition by detecting changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.
Administration of thimerosal to infant rats increases overflow of glutamate and aspartate in the prefrontal cortex: protective role of dehydroepiandrosterone sulfate.
Duszczyk-Budhathoki, Michalina; Olczak, Mieszko; Lehner, Malgorzata; Majewska, Maria Dorota
Thimerosal, a mercury-containing vaccine preservative, is a suspected factor in the etiology of neurodevelopmental disorders. We previously showed that its administration to infant rats causes behavioral, neurochemical and neuropathological abnormalities similar to those present in autism. Here we examined, using microdialysis, the effect of thimerosal on extracellular levels of neuroactive amino acids in the rat prefrontal cortex (PFC). Thimerosal administration (4 injections, i.m., 240 μg Hg/kg on postnatal days 7, 9, 11, 15) induced lasting changes in amino acid overflow: an increase of glutamate and aspartate accompanied by a decrease of glycine and alanine; measured 10-14 weeks after the injections. Four injections of thimerosal at a dose of 12.5 μg Hg/kg did not alter glutamate and aspartate concentrations at microdialysis time (but based on thimerosal pharmacokinetics, could have been effective soon after its injection). Application of thimerosal to the PFC in perfusion fluid evoked a rapid increase of glutamate overflow. Coadministration of the neurosteroid, dehydroepiandrosterone sulfate (DHEAS; 80 mg/kg; i.p.) prevented the thimerosal effect on glutamate and aspartate; the steroid alone had no influence on these amino acids. Coapplication of DHEAS with thimerosal in perfusion fluid also blocked the acute action of thimerosal on glutamate. In contrast, DHEAS alone reduced overflow of glycine and alanine, somewhat potentiating the thimerosal effect on these amino acids. Since excessive accumulation of extracellular glutamate is linked with excitotoxicity, our data imply that neonatal exposure to thimerosal-containing vaccines might induce excitotoxic brain injuries, leading to neurodevelopmental disorders. DHEAS may partially protect against mercurials-induced neurotoxicity.
Confinement, overflow, and emission of holes on SiGe surface with Ge dots: Heterogeneous hole redistribution and its application to virtual dot manipulation
Ishii, Masashi; Dhesi, Sarnjeet S.; Hamilton, Bruce
The hole confinement in Ge dots fabricated on a wetting layer in Stranski-Krastanov (S-K) growth was directed by an applied bias. At medium bias voltage, the holes overflowed from the small dots, indicating a moderate potential barrier without a notch at the boundary. The electrostatic force of the confined holes attracted excessive holes to the wetting layer. The system was energetically stabilized by the formation of a "virtual dot" in an open space enclosed by dots. At a high bias voltage, the virtual dot disappeared since the holes in the wetting layer were emitted from the surface.
Experimental and large eddy simulation results for the purging of salt water from a cavity by an overflow of fresh water
Energy Technology Data Exchange (ETDEWEB)
Kirkpatrick, M.P.; Armfield, S.W. [Sydney Univ., NSW (Australia). School of Aerospace, Mechanical and Mechatronic Engineering
This paper presents the results of an experimental and numerical investigation of a flow in which salt water is purged from a square cavity by an overflow of fresh water. Two numerical simulations are presented, one two-dimensional simulation and one three-dimensional large eddy simulation. The results are used to describe the important transport mechanisms that occur during the purging process. In particular, we propose a mechanism for the formation of the streamers observed in the experiment. We also discuss the performance of the numerical models for flows of this type. (author)
Bridge condition assessment using remote sensors.
The challenges of a deteriorating and aged infrastructure continue to challenge transportation : authorities as they align maintenance and replacement priorities with decreasing funds. The : United States is home to nearly 600,000 highway bridges of ...
In Situ Diagnostic Sensors for Thermal Protection Systems Project
National Aeronautics and Space Administration — Low-profile, embedded sensors are proposed for condition monitoring and health management (HM) of thermal protection systems. The sensors will be fabricated using a...
Imaging performance of a thin Lu2O3:Eu nanophosphor scintillating screen coupled to a high resolution CMOS sensor under X-ray radiographic conditions: comparison with Gd2O2S:Eu conventional phosphor screen
Seferis, I.; Michail, C.; Valais, I.; Zeler, J.; Liaparinos, P.; Kalyvas, N.; Fountos, G.; Zych, E.; Kandarakis, I.; Panayiotakis, G.
The purpose of the present study was to experimentally evaluate the imaging characteristics of the Lu2O3:Eu nanophosphor thin screen coupled to a high resolution CMOS sensor under radiographic conditions. Parameters such as the Modulation Transfer Function (MTF), the Normalized Noise Power Spectrum (NNPS) and the Detective Quantum Efficiency (DQE) were investigated at 70 kVp under three exposure levels (20 mAs, 63 mAs and 90 mAs). Since Lu2O3:Eu emits light in the red wavelength range, the imaging characteristics of a 33.3 mg/cm2 Gd2O2S:Eu conventional phosphor screen were also evaluated for comparison purposes. The Lu2O3:Eu nanophosphor powder was produced by the combustion synthesis, using urea as fuel. A scintillating screen of 30.2 mg/cm2 was prepared by sedimentation of the nanophosphor powder on a fused silica substrate. The CMOS/Lu2O3:Eu detector`s imaging characteristics were evaluated using an experimental method proposed by the International Electrotechnical Commission (IEC) guidelines. It was found that the CMOS/Lu2O3:Eu nanophosphor system has higher MTF values compared to the CMOS/Gd2O2S:Eu sensor/screen combination in the whole frequency range examined. For low frequencies (0 to 2 cycles/mm) NNPS values of the CMOS/Gd2O2S:Eu system were found 90% higher compared to the NNPS values of the CMOS/Lu2O3:Eu nanophosphor system, whereas from medium to high frequencies (2 to 13 cycles/mm) were found 40% higher. In contrast with the CMOS/ Gd2O2S:Eu system, CMOS/Lu2O3:Eu nanophosphor system appears to retain high DQE values in the whole frequency range examined. Our results indicate that Lu2O3:Eu nanophosphor is a promising scintillator for further research in digital X-ray radiography.
Novel Pressure Sensor for Aerospace Purposes
Directory of Open Access Journals (Sweden)
Full Text Available In this work, a novel silicon-based sensor for pressure and flow measurements is presented. To meet the special requirements of the aerospace industry a new piezoresistive pressure sensor with a flat surface has been developed, so that the flow is not affected by the sensor. To avoid bonding-wires on top of the sensor a special through-wafer connection is presented. By making other significant changes in the layout as well as in the micro fabrication process, a novel sensor has been created. It is robust enough to be laminated in fibre material, which opens new possibilities for measurements. With this sensor it is possible to characterize the condition of the flow near the separation point. This article describes the complete process from the development to the laminated sensor.
von Unold, Georg; Junker, Astrid; Altmann, Thomas
High-throughput (HT) plant phenotyping systems enable the quantitative analysis of a variety of plant features in a fully automated fashion. The comprehensive phenomics infrastructure at IPK comprises three LemnaTec conveyor belt-based (plant-to-sensor) systems for the simultaneous analysis of large numbers of individual plants of different sizes. For monitoring of environmental conditions within the plant growth area and soil conditions in individual pots, highly modular and flexible remote sensing devices are required. We present the architecture of a wireless sensor network implemented in the HT plant phenotyping systems at IPK in the frame of the German Plant Phenotyping Network (DPPN). This system comprises 350 soil monitoring modules, each measuring water content, water matrix potential, temperature and electric conductivity. Furthermore small and large sensor platforms enable the continuous monitoring of environmental parameters such as incident photosynthetic active radiation, total radiation balance, relative humidity and CO2 concentration and more. Finally we present an introduction into data management and maintenance."
Perancangan Sistem Sensor Pemonitor Lingkungan Berbasis Jaringan Sensor Nirkabel
Directory of Open Access Journals (Sweden)
Nurhuda Maulana
Full Text Available Air pollution is a problem that get a lot of people's attention, especially at campus environment. It is evocate the stakeholder of campus to monitor the environmental conditions at the campus which themed a green campus. Advances in science and technology, especially in computer and embedded systems in principle can be applied to solve this problem. There are creating an application system that is equipped with sensor to monitor the air quality level wirelessly. The system supports several environmental monitoring sensors that are connected in a wireless sensor network. The objective of this research was to design and create a sensor system that can monitor environment condition quantity by providing the appropriate output value. Sensors that used to read the air quality parameters is TGS 2600 to read the gas concentration of carbon monoxide (CO, TGS 2201 for nitrogen dioxide (NO2, GP2Y1010AU0F for particulate matter, BH1750 for light ambient, and SHT11 for humidity and temperature. This sensor system using Arduino board that based on Atmega 2560 microcontroller. This system is equipped with RTC as a time and GPS as a coordinate where the sensor system is placed as a node. The result of this reseach is the system able to read parameters as air quality monitoring well. The error reading in this sensor system is 0.69 ppm CO gas, 2.8 lx on the intensity of light, 0.22 C in temperature reading, and 0.98% in humidity readings.
Damage detection and localization algorithm using a dense sensor network of thin film sensors
Downey, Austin; Ubertini, Filippo; Laflamme, Simon
The authors have recently proposed a hybrid dense sensor network consisting of a novel, capacitive-based thin-film electronic sensor for monitoring strain on mesosurfaces and fiber Bragg grating sensors for enforcing boundary conditions on the perimeter of the monitored area. The thin-film sensor monitors local strain over a global area through transducing a change in strain into a change in capacitance. In the case of bidirectional in-plane strain, the sensor output contains the additive measurement of both principal strain components. When combined with the mature technology of fiber Bragg grating sensors, the hybrid dense sensor network shows potential for the monitoring of mesoscale systems. In this paper, we present an algorithm for the detection, quantification, and localization of strain within a hybrid dense sensor network. The algorithm leverages the advantages of a hybrid dense sensor network for the monitoring of large scale systems. The thin film sensor is used to monitor strain over a large area while the fiber Bragg grating sensors are used to enforce the uni-directional strain along the perimeter of the hybrid dense sensor network. Orthogonal strain maps are reconstructed by assuming different bidirectional shape functions and are solved using the least squares estimator to reconstruct the planar strain maps within the hybrid dense sensor network. Error between the estimated strain maps and measured strains is extracted to derive damage detecting features, dependent on the selected shape functions. Results from numerical simulations show good performance of the proposed algorithm.
Lampu Pintar Berbasis LED Dengan Multi Sensor
Ramdan, Ade; Prajitno, Dicky Rianto; Herlan, Herlan; Gojali, Elli Ahmad
In this paper, we propose a LED-based smart lamp prototype that integrated with sensor. The smart lamp use information of people and lighting confirmation, to turn on or turn off the lamp automatically. In addition, the sensor calculates and balances flash and ambient light exposure to decrease the light, so that can make energy efficiently in use. PIR (Passive Infrared Receiver) and Ultrasonic sensor is preferred to detect people condition in one place and LDR (Light Dependent Resistant) is ...
R. Sudha*1 & B. Shamile2
A Wireless Sensor Network (WSN) can communicate the information through wireless devices. WSN consists of base stations and wireless sensor nodes. These networks are used to monitor various condition are sound, pressure, temperature and cooperatively pass data through the network to the main location. The functionality parameters of a sensor are energy consumption, computational speed rate, bandwidth, memory. In this paper, it embraces application of WSN, types of WSN, security issues and sec...
Aircraft Cabin Environmental Quality Sensors
Energy Technology Data Exchange (ETDEWEB)
Gundel, Lara; Kirchstetter, Thomas; Spears, Michael; Sullivan, Douglas
The Indoor Environment Department at Lawrence Berkeley National Laboratory (LBNL) teamed with seven universities to participate in a Federal Aviation Administration (FAA) Center of Excellence (COE) for research on environmental quality in aircraft. This report describes research performed at LBNL on selecting and evaluating sensors for monitoring environmental quality in aircraft cabins, as part of Project 7 of the FAA's COE for Airliner Cabin Environmental Research (ACER)1 effort. This part of Project 7 links to the ozone, pesticide, and incident projects for data collection and monitoring and is a component of a broader research effort on sensors by ACER. Results from UCB and LBNL's concurrent research on ozone (ACER Project 1) are found in Weschler et al., 2007; Bhangar et al. 2008; Coleman et al., 2008 and Strom-Tejsen et al., 2008. LBNL's research on pesticides (ACER Project 2) in airliner cabins is described in Maddalena and McKone (2008). This report focused on the sensors needed for normal contaminants and conditions in aircraft. The results are intended to complement and coordinate with results from other ACER members who concentrated primarily on (a) sensors for chemical and biological pollutants that might be released intentionally in aircraft; (b) integration of sensor systems; and (c) optimal location of sensors within aircraft. The parameters and sensors were selected primarily to satisfy routine monitoring needs for contaminants and conditions that commonly occur in aircraft. However, such sensor systems can also be incorporated into research programs on environmental quality in aircraft cabins.
Duan, Yixiang; Jia, Quanxi; Cao, Wenqing
A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.
Impact of river overflowing on trace element contamination of volcanic soils in south Italy: Part I. Trace element speciation in relation to soil properties
Energy Technology Data Exchange (ETDEWEB)
Adamo, P. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, Portici, 80055 Naples (Italy)]. E-mail: email@example.com; Zampella, M. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, Portici, 80055 Naples (Italy); Gianfreda, L. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, Portici, 80055 Naples (Italy); Renella, G. [Dipartimento di Scienza del Suolo e Nutrizione della Pianta, Universita di Firenze, P.le delle Cascine 28, 50144 Firenze (Italy); Rutigliano, F.A. [Dipartimento di Scienze Ambientali, Seconda Universita di Napoli, Via Vivaldi 43, 81100 Caserta (Italy); Terribile, F. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, Portici, 80055 Naples (Italy)
Volcanic soils affected by different numbers of polluted river flooding events were investigated. Chromium and Cu were the major soil contaminants. Nickel, Fe, Zn and Mn total content never exceeded the Italian mandatory limits. The distribution of Cr and Cu total contents among studied soils indicated that only Cr contamination was related to overflowing events. In polluted soils, sequential chemical extractions revealed a preferential association of Cr and Cu with organic forms. A progressive Cr insolubilization with ageing was observed. Significant amounts of Cr and Cu were extracted by NH{sub 4}-oxalate, suggesting metals association with short-range-order aluminosilicates and organo-mineral complexes. Possible methodological drawbacks in the use of the EU-BCR chemical speciation protocol on volcanic soils are discussed. Micromorphology and SEM/WDS analyses revealed Cr and Cu enriched silt and clay coatings in surface and subsurface soil horizons, suggesting a transfer of metal-rich sediments along the soil pore network with water movement. - River overflowing adds up soil with Cr-rich sediments which, although chemically low reactive, transfer metal along the soil pore network during water movement.
Sensor anomaly detection in wireless sensor networks for healthcare.
Haque, Shah Ahsanul; Rahman, Mustafizur; Aziz, Syed Mahfuzul
Wireless Sensor Networks (WSN) are vulnerable to various sensor faults and faulty measurements. This vulnerability hinders efficient and timely response in various WSN applications, such as healthcare. For example, faulty measurements can create false alarms which may require unnecessary intervention from healthcare personnel. Therefore, an approach to differentiate between real medical conditions and false alarms will improve remote patient monitoring systems and quality of healthcare service afforded by WSN. In this paper, a novel approach is proposed to detect sensor anomaly by analyzing collected physiological data from medical sensors. The objective of this method is to effectively distinguish false alarms from true alarms. It predicts a sensor value from historic values and compares it with the actual sensed value for a particular instance. The difference is compared against a threshold value, which is dynamically adjusted, to ascertain whether the sensor value is anomalous. The proposed approach has been applied to real healthcare datasets and compared with existing approaches. Experimental results demonstrate the effectiveness of the proposed system, providing high Detection Rate (DR) and low False Positive Rate (FPR).
Triboluminescent Fiber-Optic Sensors Measure Stresses
Rogowski, Robert S.
Triboluminescence exploited in fiber-optic sensor system for measuring changes in pressures, strains, vibrations, and acoustic emissions, in structural members. Sensors embedded in members for in situ monitoring of condition of structure. System passive in sense no source of radiation required to interrogate optical fiber. Technique has potential for wide range of applications in which detection and measurement of structural stress required.
Lamberti, Fabrizio; Sanna, Andrea; Rokne, Jon
Sensors are becoming ubiquitous in all areas of science, technology, and society. In this Special Issue on "Sensors for Entertainment", developments in progress and the current state of application scenarios for sensors in the field of entertainment is explored.
Diamond Sensors for Energy Frontier Experiments
Schnetzer, Steve
We discuss the use of diamond sensors in high-energy, high-i ntensity collider experiments. Re- sults from diamond sensor based beam conditions monitors in the ATLAS and CMS experiments at the CERN Large Hadron Collider (LHC) are presented and pla ns for diamond based luminosity monitors for the upcoming LHC run are described. We describe recent measurements on single crystal diamond sensors that indicate a polarization effec t that causes a reduction of charge col- lection efficiency as a function of particle flux. We conclude by describing new developments on the promising technology of 3D diamond sensors.
A Large Area Tactile Sensor Patch Based on Commercial Force Sensors
Directory of Open Access Journals (Sweden)
Alfonso García-Cerezo
Full Text Available This paper reports the design of a tactile sensor patch to cover large areas of robots and machines that interact with human beings. Many devices have been proposed to meet such a demand. These realizations are mostly custom-built or developed in the lab. The sensor of this paper is implemented with commercial force sensors. This has the benefit of a more foreseeable response of the sensor if its behavior is understood as the aggregation of readings from all the individual force sensors in the array. A few reported large area tactile sensors are also based on commercial sensors. However, the one in this paper is the first of this kind based on the use of polymeric commercial force sensing resistors (FSR as unit elements of the array or tactels, which results in a robust sensor. The paper discusses design issues related to some necessary modifications of the force sensor, its assembly in an array, and the signal conditioning. The patch has 16 × 9 force sensors mounted on a flexible printed circuit board with a spatial resolution of 18.5 mm. The force range of a tactel is 6 N and its sensitivity is 0.6 V/N. The array is read at a rate of 78 frames per second. Finally, two simple application examples are also carried out with the sensor mounted on the forearm of a rescue robot that communicates with the sensor through a CAN bus.
Sensor Placement Optimization using Chama
Energy Technology Data Exchange (ETDEWEB)
Klise, Katherine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Geotechnology and Engineering Dept.; Nicholson, Bethany L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Discrete Math and Optimization Dept.; Laird, Carl Damon [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Discrete Math and Optimization Dept.
Continuous or regularly scheduled monitoring has the potential to quickly identify changes in the environment. However, even with low - cost sensors, only a limited number of sensors can be deployed. The physical placement of these sensors, along with the sensor technology and operating conditions, can have a large impact on the performance of a monitoring strategy. Chama is an open source Python package which includes mixed - integer, stochastic programming formulations to determine sensor locations and technology that maximize monitoring effectiveness. The methods in Chama are general and can be applied to a wide range of applications. Chama is currently being used to design sensor networks to monitor airborne pollutants and to monitor water quality in water distribution systems. The following documentation includes installation instructions and examples, description of software features, and software license. The software is intended to be used by regulatory agencies, industry, and the research community. It is assumed that the reader is familiar with the Python Programming Language. References are included for addit ional background on software components. Online documentation, hosted at http://chama.readthedocs.io/, will be updated as new features are added. The online version includes API documentation .
Energy Technology Data Exchange (ETDEWEB)
Joshi, Pooran C.; Killough, Stephen M.; Kuruganti, Phani Teja
A wireless sensor platform and methods of manufacture are provided. The platform involves providing a plurality of wireless sensors, where each of the sensors is fabricated on flexible substrates using printing techniques and low temperature curing. Each of the sensors can include planar sensor elements and planar antennas defined using the printing and curing. Further, each of the sensors can include a communications system configured to encode the data from the sensors into a spread spectrum code sequence that is transmitted to a central computer(s) for use in monitoring an area associated with the sensors.
High quality new type spark plug pressure sensor; Koseino plug gata shiatsu sensor ni tsuite
Energy Technology Data Exchange (ETDEWEB)
Urakawa, H.; Yanagihara, S.; Kawa, T. [Tsukasa Sokken Co. Ltd., Tokyo (Japan); Enomoto, Y. [Musashi Institute of Technology, Tokyo (Japan); Sato, T. [Dai Ichi Institute of Technology, Kagoshima (Japan); Gotthard, E.
Investigations were made on a spark plug type pressure sensor using GaPO4 piezoelectric material developed recently by AVL Corporation. This sensor has the ignition electrode installed decentered to assure the installing position for the pressure sensor, where the small pressure sensor with a diameter of 4.4 mm, model GU12P is installed on the side. Experiments were performed on this sensor, a water cooled sensor for comparison, and a cooling-free type sensor for reference. The engine was operated at an outlet cooling water temperature maintained constant at 80 degC, and experimented in a normal combustion condition with full load at 2000 rpm and 4000 rpm, in a knocking condition with full load at 2000 rpm, and in a transient condition from full load at 4000 rpm to no load at 1300 rpm. As a result, it was made clear that the spark plug type pressure sensor showed an output of the same level as that with the water cooled sensor in the normal combustion pressure. Load change drift under the transient condition was found as good as 2.5% FS at maximum. No effect of columnar vibration was discovered, and a knocking waveform of 14 kHz was observed. 6 refs., 12 figs., 1 tab.
Directory of Open Access Journals (Sweden)
Zainab Yunusa
Full Text Available In this paper a review of different technologies for gas sensors is presented. The different types of gas sensors technologies including catalytic gas sensor, electrochemical gas sensors, thermal conductivity gas sensor, optical gas sensor and acoustic gas sensor are discussed together with their principle of operation. The Surface Acoustic Wave Gas Sensor technology is discussed in greater detail. The advantages and disadvantages of each sensor technology are also highlighted. All these technologies have been used for several decades for the development of highly sensitive and responsive gas sensors for the detection of flammable and hazardous gases. However, for improved sensitivity and selectivity for these sensors, future trends and outlook for researchers are suggested in the conclusion of this article.
Corrosion rate sensors for soil, water and concrete
Energy Technology Data Exchange (ETDEWEB)
Ansuini, F. [Electrochemical Devices, Inc., Albion, RI (United States); Yaffe, M. [Gamry Instruments, Inc., Willow Grove, PA (United States); Chaker, V. [Port Authority of New York and New Jersey, New York, NY (United States)
Present concern over the condition of the infrastructure has created a need to monitor corrosion of large field structures in real time. New sensors have been developed for measuring corrosion rates of steel in concrete, underground and aqueous environments. This paper will discuss sensor designs including both the transducer and the electronics as well as field experience with these sensors in concrete.
Wireless Fluid-Level Sensors for Harsh Environments
Woodward, Stanley E.
Magnetic-field-response sensors have been developed for use in measuring levels of fluids under extreme conditions. The sensors work without wire connections or direct physical contact with power sources, microprocessors, data-acquisition equipment, or electrical circuitry. For fuel-level sensors, the absence of wire connections offers an important safety advantage in elimination of potential ignition sources.
An IC-compatible polyimide pressure sensor with capacitive readout
Pedersen, M.; Meijerink, M.G.H.; Olthuis, Wouter; Bergveld, Piet
A capacitive differential pressure sensor has been developed. The process used for the fabrication of the sensor is IC-compatible, meaning that the device potentially can be integrated on one chip with a suitable signal-conditioning circuit. A sensor for a differential pressure of ±1 bar has been
40 CFR 1065.210 - Work input and output sensors.
... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Work input and output sensors. 1065... Ambient Conditions § 1065.210 Work input and output sensors. (a) Application. Use instruments as specified... sensors, transducers, and meters that meet the specifications in Table 1 of § 1065.205. Note that your...
A New Ablative Heat Shield Sensor Suite Project
Bose, Deepak
A new sensor suite is developed to measure performance of ablative thermal protection systems used in planetary entry vehicles for robotic and human exploration. The new sensor suite measures ablation of the thermal protection system under extreme heating encountered during planetary entry. The sensor technology is compatible with a variety of thermal protection materials, and is applicable over a wide range of entry conditions.
Dynamic Strain and Crack Monitoring Sensor Project
National Aeronautics and Space Administration — The development of condition-based monitoring sensor network systems has the potential to provide an enhanced aircraft safety by real time assessment of the...
Conklin, John Albert
This dissertation presents the design of a modular, fiber-optic sensor and the results obtained from testing the modular sensor. The modular fiber-optic sensor is constructed in such manner that the sensor diaphragm can be replaced with different configurations to detect numerous physical phenomena. Additionally, different fiber-optic detection systems can be attached to the sensor. Initially, the modular sensor was developed to be used by university of students to investigate realistic optical sensors and detection systems to prepare for advance studies of micro-optical mechanical systems (MOMS). The design accomplishes this by doing two things. First, the design significantly lowers the costs associated with studying optical sensors by modularizing the sensor design. Second, the sensor broadens the number of physical phenomena that students can apply optical sensing techniques to in a fiber optics sensor course. The dissertation is divided into seven chapters covering the historical development of fiber-optic sensors, a theoretical overview of fiber-optic sensors, the design, fabrication, and the testing of the modular sensor developed in the course of this work. Chapter 1 discusses, in detail, how this dissertation is organized and states the purpose of the dissertation. Chapter 2 presents an historical overview of the development of optical fibers, optical pressure sensors, and fibers, optical pressure sensors, and optical microphones. Chapter 3 reviews the theory of multi-fiber optic detection systems, optical microphones, and pressure sensors. Chapter 4 presents the design details of the modular, optical sensor. Chapter 5 delves into how the modular sensor is fabricated and how the detection systems are constructed. Chapter 6 presents the data collected from the microphone and pressure sensor configurations of the modular sensor. Finally, Chapter 7 discusses the data collected and draws conclusions about the design based on the data collected. Chapter 7 also
Optimal sensor placement using machine learning
Semaan, Richard
A new method for optimal sensor placement based on variable importance of machine learned models is proposed. With its simplicity, adaptivity, and low computational cost, the method offers many advantages over existing approaches. The new method is implemented on an airfoil equipped with a Coanda actuator. The analysis is based on flow field data obtained from 2D unsteady Reynolds averaged Navier-Stokes (URANS) simulations with different actuation conditions. The optimal sensor locations is compared against the current de-facto standard of maximum POD modal amplitude location, and against a brute force approach that scans all possible sensor combinations. The results show that both the flow conditions and the type of sensor have an effect on the optimal sensor placement, whereas the choice of the response function appears to have limited influence.
Electrochemical sensor monitoring of volcanic gases
Roberts, Tjarda; Freshwater, Ray; Oppenheimer, Clive; Saffell, John; Jones, Rod; Griffiths, Paul; Braban, Christine; Mead, Iqbal
Advances in instrumentation have fuelled a recent growth of interest in using portable sensor systems for environmental monitoring of pollution. Developments in wireless technology are enabling such systems to operate remotely and autonomously, generating a wealth of environmental data. We report here on the application of miniature Alphasense electrochemical sensors to the detection and characterisation of gases in volcanic plumes. A highly portable sensor system was developed to operate an array of 6 low cost electrochemical sensors to detect CO, H2, HCl, SO2, H2S and NO2 at 1 Hz. A miniature pump draws air over all sensors simultaneously (i.e. sensors arranged in parallel). The sensor output in these campaigns was logged on PDAs for real-time viewing, and later download (with a view to future data-streaming). The instrument was deployed at a number of volcanoes and was subject to extremely harsh conditions including highly acidic environments, low (Antarctic) temperatures, and transport over rough terrain. Analysis methods are demonstrated that consider calibration, cross-sensitivities of the sensors to multiple gases, differing sensor response times, temperature dependence, and background sensor drift with time. The analysis is applied to a range of plume field-measurements to extract gas concentrations ranging from 100's ppmv to sub-ppmv and to characterise the individual volcano emissions. Applications of similar sensor systems for real-time long-term monitoring of volcanic emissions (which may indicate and ultimately predict eruptive behavior), and UAV and balloon-borne plume sampling are now already being realised. This work focused on demonstrating the application of electrochemical sensors to monitoring of environmental pollution from volcanoes. Other applications for similar sensors include the near-source monitoring of industrial emissions, and of pollutant levels enhanced by traffic emissions in the urban environment.
Laser Fiber Optic Sensor for Human Biomagnetic Measurements
National Research Council Canada - National Science Library
Churchill, Russell
...) is the superconducting quantum interference device (SQUID) magnetometer. However, the SQUID sensor requires cryogenic instrumentation, thereby limiting the conditions under which the magnetometer can be used and contributing...
Dynamic gauge adjustment of high-resolution X-band radar data for convective rain storms: Model-based evaluation against measured combined sewer overflow
DEFF Research Database (Denmark)
Borup, Morten; Grum, Morten; Linde, Jens Jørgen
Numerous studies have shown that radar rainfall estimates need to be adjusted against rain gauge measurements in order to be useful for hydrological modelling. In the current study we investigate if adjustment can improve radar rainfall estimates to the point where they can be used for modelling...... overflows from urban drainage systems, and we furthermore investigate the importance of the aggregation period of the adjustment scheme. This is done by continuously adjusting X-band radar data based on the previous 5–30 min of rain data recorded by multiple rain gauges and propagating the rainfall...... estimates through a hydraulic urban drainage model. The model is built entirely from physical data, without any calibration, to avoid bias towards any specific type of rainfall estimate. The performance is assessed by comparing measured and modelled water levels at a weir downstream of a highly impermeable...
Probabilistic modelling of overflow, surcharge and flooding in urban drainage using the first-order reliability method and parameterization of local rain series
DEFF Research Database (Denmark)
Thorndahl, Søren; Willems, Patrick
Failure of urban drainage systems may occur due to surcharge or flooding at specific manholes in the system, or due to overflows from combined sewer systems to receiving waters. To quantify the probability or return period of failure, standard approaches make use of the simulation of design storms...... or long historical rainfall series in a hydrodynamic model of the urban drainage system. In this paper, an alternative probabilistic method is investigated: the First Order Reliability Method (FORM). To apply this method, a long rainfall time series was divided in rain storms (rain events), and each rain...... storm conceptualized to a synthetic rainfall hyetograph by a Gaussian shape with the parameters: rain storm depth, duration and peak intensity. Probability distributions were calibrated for these three parameters and used on the basis of the failure probability estimation, together with a hydrodynamic...
Cartography of flood hazard by overflowing rivers using hydraulic modeling and geographic information system: Oued El Harrach case (North of Algeria
Directory of Open Access Journals (Sweden)
S. W. Astite
Full Text Available The aim of the present study is the management of flood risk through the use of cartography of flood hazards by overflowing rivers. This cartography is developed using modern simulation tools namely the hydraulic model (HECRAS as well as the Geographic Information System (ArcGis. The study concerns Oued El Harrach (North of Algeria surrounding area which has been subject to several floods causing significant human and material damage. This loss is a consequence of the use flood zones as habitats for people. This can be avoided in the future by use the mapping of the spatial extent of the flood hazard on the land of the Oued El Harrach. Hence the importance of the cartography developed in this study as an essential tool for decision makers in prevention, protection and management of flood risks.
Impact of river overflowing on trace element contamination of volcanic soils in south Italy: part I. Trace element speciation in relation to soil properties.
Adamo, P; Zampella, M; Gianfreda, L; Renella, G; Rutigliano, F A; Terribile, F
Volcanic soils affected by different numbers of polluted river flooding events were investigated. Chromium and Cu were the major soil contaminants. Nickel, Fe, Zn and Mn total content never exceeded the Italian mandatory limits. The distribution of Cr and Cu total contents among studied soils indicated that only Cr contamination was related to overflowing events. In polluted soils, sequential chemical extractions revealed a preferential association of Cr and Cu with organic forms. A progressive Cr insolubilization with ageing was observed. Significant amounts of Cr and Cu were extracted by NH(4)-oxalate, suggesting metals association with short-range-order aluminosilicates and organo-mineral complexes. Possible methodological drawbacks in the use of the EU-BCR chemical speciation protocol on volcanic soils are discussed. Micromorphology and SEM/WDS analyses revealed Cr and Cu enriched silt and clay coatings in surface and subsurface soil horizons, suggesting a transfer of metal-rich sediments along the soil pore network with water movement.
Sensors Applications, Volume 4, Sensors for Automotive Applications
Marek, Jiri; Trah, Hans-Peter; Suzuki, Yasutoshi; Yokomori, Iwao
An international team of experts from the leading companies in this field gives a detailed picture of existing as well as future applications. They discuss in detail current technologies, design and construction concepts, market considerations and commercial developments. Topics covered include vehicle safety, fuel consumption, air conditioning, emergency control, traffic control systems, and electronic guidance using radar and video. Meeting the growing need for comprehensive information on the capabilities, potentials and limitations of modern sensor systems, Sensors Applications is a book series covering the use of sophisticated technologies and materials for the creation of advanced sensors and their implementation in the key areas process monitoring, building control, health care, automobiles, aerospace, environmental technology and household appliances.
Watershed-scale impacts of stormwater green infrastructure on hydrology, nutrient fluxes, and combined sewer overflows in the mid-Atlantic region.
Pennino, Michael J; McDonald, Rob I; Jaffe, Peter R
Stormwater green infrastructure (SGI), including rain gardens, detention ponds, bioswales, and green roofs, is being implemented in cities across the globe to reduce flooding, combined sewer overflows, and pollutant transport to streams and rivers. Despite the increasing use of urban SGI, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Washington, DC, Montgomery County, MD, and Baltimore County, MD, were selected based on the availability of data on SGI, water quality, and stream flow. The cumulative impact of SGI was evaluated over space and time by comparing watersheds with and without SGI, and by assessing how long-term changes in SGI impact hydrologic and water quality metrics over time. Most Mid-Atlantic municipalities have a goal of achieving 10-20% of the landscape drain runoff through SGI by 2030. Of these areas, Washington, DC currently has the greatest amount of SGI (12.7% of the landscape drained through SGI), while Baltimore County has the lowest (7.9%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI have less flashy hydrology, with 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff. Watersheds with more SGI also show 44% less NO3(-) and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in phosphorus exports or combined sewer overflows in watersheds with greater SGI. When comparing individual watersheds over time, increases in SGI corresponded to non-significant reductions in hydrologic flashiness compared to watersheds with no change in SGI. While the implementation of SGI is somewhat in its infancy in some regions, cities are beginning to have a scale of SGI where there are statistically significant differences in hydrologic patterns and water quality. Copyright © 2016 The Authors
Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology, Nitrogen Fluxes, and Combined Sewer Overflows in the Baltimore, MD and Washington, DC area
Jaffe, P. R.; Pennino, M. J.; McDonald, R.
Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Baltimore County, MD, Montgomery County, MD, and Washington, DC, were selected based on the availability of data on SGI, water quality, and stream flow. The watershed scale impact of SGI was evaluated by assessing how increased spatial density of SGI correlates with stream hydrology and nitrogen exports over space and time. The most common SGI types were detention ponds (58%), followed by marshes (12%), sand filters (9%), wet ponds (7%), infiltration trenches (4%), and rain gardens (2%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI (>10% SGI) have 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff than watersheds with lower SGI. Watersheds with more SGI also show 44% less NO3- and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in combined sewer overflows in watersheds with greater SGI. Based on specific SGI types, infiltration trenches (R2 = 0.35) showed the strongest correlation with hydrologic metrics, likely due to their ability to attenuate flow, while bioretention (R2 = 0.19) and wet ponds (R2 = 0.12) showed stronger relationships with nitrogen compared to other SGI types, possibly due to greater denitrification in these sites. When comparing individual watersheds over time, increases in SGI corresponded to non-significant reductions in hydrologic flashiness and combined sewer overflows compared to watersheds with no change in SGI. This study shows that while implementation of SGI is ongoing, some regions are beginning to have enough SGI to see significant impacts on hydrology and water quality at the watershed scale.
Ventilation history of Nordic Seas overflows during the last (de)glacial period revealed by species-specific benthic foraminiferal 14C dates
Ezat, Mohamed M.; Rasmussen, Tine L.; Thornalley, David J. R.; Olsen, Jesper; Skinner, Luke C.; Hönisch, Bärbel; Groeneveld, Jeroen
Formation of deep water in the high-latitude North Atlantic is important for the global meridional ocean circulation, and its variability in the past may have played an important role in regional and global climate change. Here we study ocean circulation associated with the last (de)glacial period, using water-column radiocarbon age reconstructions in the Faroe-Shetland Channel, southeastern Norwegian Sea, and from the Iceland Basin, central North Atlantic. The presence of tephra layer Faroe Marine Ash Zone II, dated to 26.7 ka, enables us to determine that the middepth (1179 m water depth) and shallow subsurface reservoir ages were 1500 and 1100 14C years, respectively, older during the late glacial period compared to modern, suggesting substantial suppression of the overturning circulation in the Nordic Seas. During the late Last Glacial Maximum and the onset of deglaciation ( 20-18 ka), Nordic Seas overflow was weak but active. During the early deglaciation ( 17.5-14.5 ka), our data reveal large differences between 14C ventilation ages that are derived from dating different benthic foraminiferal species: Pyrgo and other miliolid species yield ventilation ages >6000 14C years, while all other species reveal ventilation ages changes or that miliolid-based 14C ages are biased due to taphonomic or vital processes. Implications of each interpretation are discussed. Regardless of this "enigma," the onset of the Bølling-Allerød interstadial (14.5 ka) is clearly marked by an increase in middepth Nordic Seas ventilation and the renewal of a stronger overflow.
Resilience of sewage services to climate change uncertainty: analysis of the management of sewer overflows in two Parisian suburban areas.
Rioust, E.; Deroubaix, J. F.; Barroca, B.; Bonierbale, T.; de Gouvello, B.; Deutsch, J. C.; Hubert, G.
This paper considers the resilience perspective as an approach for understanding social and political vulnerabilities of urban services. The authors examine to what extend uncertainty due to climate change may affect the resilience of these urban services. The resilience perspective is increasingly used for analysing social groups' capacities to adapt to and live with disturbances. A lot of work on resilience has focused on the capacity to absorb shocks and still maintain functions. But there is also another aspect of resilience, which leads to take into account systems vulnerabilities and to aim at understanding their equilibrium and re-organization capacity. The purpose with this paper is to assess sewage systems capacities to adapt to climate change. Indeed, climate change could cause an increase of extreme rain events and, as a matter of consequence, an increase of sewer overflows and flooding of urbanised areas. Sewer systems have to cope with this change that may gravely affect urban planning. In recent studies of political science, risk management has been considered as a public policy involving and resulting from complex social, political and technical processes (Gilbert et al. 2003). From this point of view, the management of wastewaters and storm waters has to be considered not only as a technical but also as a political and a social system. Therefore, political science can be a fruitful perspective to understand the stakeholders perceptions of uncertainty and the way they are going to integrate this issue in their practices. The authors analyse the adaptive capacities of two sewer systems located in the Parisian suburban area. The chosen areas are highly populated. Each network is managed within a political and administrative unit called "Département". Both authorities of these "Départements" implement a public sewage service. Nonetheless these networks are connected and part of the greater Paris sewage policy. In both areas a real time control of
High-speed imaging at high x-ray energy: CdTe sensors coupled to charge-integrating pixel array detectors
Energy Technology Data Exchange (ETDEWEB)
Becker, Julian; Tate, Mark W.; Shanks, Katherine S.; Philipp, Hugh T.; Weiss, Joel T.; Purohit, Prafull [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Chamberlain, Darol [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); Gruner, Sol M., E-mail: email@example.com [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)
Pixel Array Detectors (PADs) consist of an x-ray sensor layer bonded pixel-by-pixel to an underlying readout chip. This approach allows both the sensor and the custom pixel electronics to be tailored independently to best match the x-ray imaging requirements. Here we describe the hybridization of CdTe sensors to two different charge-integrating readout chips, the Keck PAD and the Mixed-Mode PAD (MM-PAD), both developed previously in our laboratory. The charge-integrating architecture of each of these PADs extends the instantaneous counting rate by many orders of magnitude beyond that obtainable with photon counting architectures. The Keck PAD chip consists of rapid, 8-frame, in-pixel storage elements with framing periods <150 ns. The second detector, the MM-PAD, has an extended dynamic range by utilizing an in-pixel overflow counter coupled with charge removal circuitry activated at each overflow. This allows the recording of signals from the single-photon level to tens of millions of x-rays/pixel/frame while framing at 1 kHz. Both detector chips consist of a 128×128 pixel array with (150 µm){sup 2} pixels.
EDITORIAL: Humidity sensors Humidity sensors
Regtien, Paul P. L.
produced at relatively low cost. Therefore, they find wide use in lots of applications. However, the method requires a material that possesses some conflicting properties: stable and reproducible relations between air humidity, moisture uptake and a specific property (for instance the length of a hair, the electrical impedance of the material), fast absorption and desorption of the water vapour (to obtain a short response time), small hysteresis, wide range of relative humidity (RH) and temperature-independent output (only responsive to RH). For these reasons, much research is done and is still going on to find suitable materials that combine high performance and low price. In this special feature, three of the four papers report on absorption sensors, all with different focus. Aziz et al describe experiments with newly developed materials. The surface structure is extensively studied, in view of its ability to rapidly absorb water vapour and exhibit a reproducible change in the resistance and capacitance of the device. Sanchez et al employ optical fibres coated with a thin moisture-absorbing layer as a sensitive humidity sensor. They have studied various coating materials and investigated the possibility of using changes in optical properties of the fibre (here the lossy mode resonance) due to a change in humidity of the surrounding air. The third paper, by Weremczuk et al, focuses on a cheap fabrication method for absorption-based humidity sensors. The inkjet technology appears to be suitable for mass fabrication of such sensors, which is demonstrated by extensive measurements of the electrical properties (resistance and capacitance) of the absorbing layers. Moreover, they have developed a model that describes the relation between humidity and the electrical parameters of the moisture-sensitive layer. Despite intensive research, absorption sensors still do not meet the requirements for high accuracy applications. The dew-point temperature method is more appropriate
Development of an acoustic sensor for a geothermal Borehole Televiewer
Energy Technology Data Exchange (ETDEWEB)
Wonn, J.W.
The objective of this project is to upgrade acoustic sensor technology such that appropriate well logging instruments can be made to operate under the hostile environment conditions anticipated in geothermal resource exploration and evaluation. The Borehole Televiewer (BHTV) was selected as the vehicle for this sensor improvement work, primarily because of its demonstrated ability to detect and characterize fractures under sub-geothermal conditions. The work done toward providing an improved sensor for the televiewer is described. An experimental sensor concept was devised, incorporating a thin metal acoustic window, an improved, high-temperature internal coupling fluid, and thermally resistant sensor internals. During an autoclave test, it was successfully demonstrated that the resulting experimental sensor design concept provides the basic target detection and characterization functions required of a fracture mapping, Borehole Televiewer under simulated geothermal conditions. In particular, the experimental sensor remained operational at 275/sup 0/C and 7000 psi.
Development of an acoustic sensor for a geothermal borehole televiewer
Energy Technology Data Exchange (ETDEWEB)
Wonn, J.W.
The objective of this project is to upgrade acoustic sensor technology such that appropriate well logging instruments can be made to operate under the hostile environment conditions anticipated in geothermal resource exploration and evaluation. The Borehole Televiewer (BHTV) was selected as the vehicle for this sensor improvement work, primarily because of its demonstrated ability to detect and characterize fractures under sub-geothermal conditions. The work done toward providing an improved sensor for the televiewer is described. An experimental sensor concept was devised, incorporating a thin metal acoustic window, an improved, high-temperature internal coupling fluid, and thermally resistant sensor internals. During an autoclave test, it was successfully demonstrated that the resulting experimental sensor design concept provides the basic target detection and characterization functions required of a fracture mapping, Borehole Televiewer under simulated geothermal conditions. In particular, the experimental sensor remained operational at 275/sup 0/C and 7000 psi.
Pei, Chunmei; Guo, Huiling; Yang, Xiuqing; Wang, Yangqiu; Zhang, Xiaojing; Ye, Hairong
International audience; The technological innovation in electronics makes nowadays mobile phone more than a simple communication tool: it becomes a portable electronic device with integrated functions, such as listening to music, watching movies, taking photos, etc. To achieve these, many kinds of advanced sensor are used. In this paper, several applications of sensor in smart phone are introduced including Image Sensor, Fingerprint Identification Sensor, Photo-electric Sensor, Acceleration S...
Research of marine sensor web based on SOA and EDA
Jiang, Yongguo; Dou, Jinfeng; Guo, Zhongwen; Hu, Keyong
A great deal of ocean sensor observation data exists, for a wide range of marine disciplines, derived from in situ and remote observing platforms, in real-time, near-real-time and delayed mode. Ocean monitoring is routinely completed using sensors and instruments. Standardization is the key requirement for exchanging information about ocean sensors and sensor data and for comparing and combining information from different sensor networks. One or more sensors are often physically integrated into a single ocean `instrument' device, which often brings in many challenges related to diverse sensor data formats, parameters units, different spatiotemporal resolution, application domains, data quality and sensors protocols. To face these challenges requires the standardization efforts aiming at facilitating the so-called Sensor Web, which making it easy to provide public access to sensor data and metadata information. In this paper, a Marine Sensor Web, based on SOA and EDA and integrating the MBARI's PUCK protocol, IEEE 1451 and OGC SWE 2.0, is illustrated with a five-layer architecture. The Web Service layer and Event Process layer are illustrated in detail with an actual example. The demo study has demonstrated that a standard-based system can be built to access sensors and marine instruments distributed globally using common Web browsers for monitoring the environment and oceanic conditions besides marine sensor data on the Web, this framework of Marine Sensor Web can also play an important role in many other domains' information integration.
Rankin, Arturo L.; Matthies, Larry H.
Robust mud detection is a critical perception requirement for Unmanned Ground Vehicle (UGV) autonomous offroad navigation. A military UGV stuck in a mud body during a mission may have to be sacrificed or rescued, both of which are unattractive options. There are several characteristics of mud that may be detectable with appropriate UGV-mounted sensors. For example, mud only occurs on the ground surface, is cooler than surrounding dry soil during the daytime under nominal weather conditions, is generally darker than surrounding dry soil in visible imagery, and is highly polarized. However, none of these cues are definitive on their own. Dry soil also occurs on the ground surface, shadows, snow, ice, and water can also be cooler than surrounding dry soil, shadows are also darker than surrounding dry soil in visible imagery, and cars, water, and some vegetation are also highly polarized. Shadows, snow, ice, water, cars, and vegetation can all be disambiguated from mud by using a suite of sensors that span multiple bands in the electromagnetic spectrum. Because there are military operations when it is imperative for UGV's to operate without emitting strong, detectable electromagnetic signals, passive sensors are desirable. JPL has developed a daytime mud detection capability using multiple passive imaging sensors. Cues for mud from multiple passive imaging sensors are fused into a single mud detection image using a rule base, and the resultant mud detection is localized in a terrain map using range data generated from a stereo pair of color cameras.
Resistive flex sensors: a survey
Saggio, Giovanni; Riillo, Francesco; Sbernini, Laura; Quitadamo, Lucia Rita
Resistive flex sensors can be used to measure bending or flexing with relatively little effort and a relatively low budget. Their lightness, compactness, robustness, measurement effectiveness and low power consumption make these sensors useful for manifold applications in diverse fields. Here, we provide a comprehensive survey of resistive flex sensors, taking into account their working principles, manufacturing aspects, electrical characteristics and equivalent models, useful front-end conditioning circuitry, and physic-bio-chemical aspects. Particular effort is devoted to reporting on and analyzing several applications of resistive flex sensors, related to the measurement of body position and motion, and to the implementation of artificial devices. In relation to the human body, we consider the utilization of resistive flex sensors for the measurement of physical activity and for the development of interaction/interface devices driven by human gestures. Concerning artificial devices, we deal with applications related to the automotive field, robots, orthosis and prosthesis, musical instruments and measuring tools. The presented literature is collected from different sources, including bibliographic databases, company press releases, patents, master's theses and PhD theses.
Distributed sensor coordination for advanced energy systems
Energy Technology Data Exchange (ETDEWEB)
Tumer, Kagan [Oregon State Univ., Corvallis, OR (United States). School of Mechanical, Industrial and Manufacturing Engineering
Motivation: The ability to collect key system level information is critical to the safe, efficient and reliable operation of advanced power systems. Recent advances in sensor technology have enabled some level of decision making directly at the sensor level. However, coordinating large numbers of sensors, particularly heterogeneous sensors, to achieve system level objectives such as predicting plant efficiency, reducing downtime or predicting outages requires sophisticated coordination algorithms. Indeed, a critical issue in such systems is how to ensure the interaction of a large number of heterogenous system components do not interfere with one another and lead to undesirable behavior. Objectives and Contributions: The long-term objective of this work is to provide sensor deployment, coordination and networking algorithms for large numbers of sensors to ensure the safe, reliable, and robust operation of advanced energy systems. Our two specific objectives are to: 1. Derive sensor performance metrics for heterogeneous sensor networks. 2. Demonstrate effectiveness, scalability and reconfigurability of heterogeneous sensor network in advanced power systems. The key technical contribution of this work is to push the coordination step to the design of the objective functions of the sensors, allowing networks of heterogeneous sensors to be controlled. By ensuring that the control and coordination is not specific to particular sensor hardware, this approach enables the design and operation of large heterogeneous sensor networks. In addition to the coordination coordination mechanism, this approach allows the system to be reconfigured in response to changing needs (e.g., sudden external events requiring new responses) or changing sensor network characteristics (e.g., sudden changes to plant condition). Impact: The impact of this work extends to a large class of problems relevant to the National Energy Technology Laboratory including sensor placement, heterogeneous sensor
Rapid procedure to calibrate EC-10 and EC-20 capacitance sensors ...
African Journals Online (AJOL)
A rapid calibration procedure for EC-10 and EC-20 sensors is introduced to promote the commercial use of these sensors for hydroponic irrigation management in coir. The method is comprised of taking one sensor reading, by a sensor installed under hydroponic crop production conditions, and one gravimetric sample, ...
Rapid procedure to calibrate EC-10 and EC-20 capacitance sensors ...
African Journals Online (AJOL)
Oct 4, 2013 ... A rapid calibration procedure for EC-10 and EC-20 sensors is introduced to promote the commercial use of these sensors for hydroponic irrigation management in coir. The method is comprised of taking one sensor reading, by a sensor installed under hydroponic crop production conditions, and one ...
Towards Sensor Database Systems
DEFF Research Database (Denmark)
Bonnet, Philippe; Gehrke, Johannes; Seshadri, Praveen
. These systems lack flexibility because data is extracted in a predefined way; also, they do not scale to a large number of devices because large volumes of raw data are transferred regardless of the queries that are submitted. In our new concept of sensor database system, queries dictate which data is extracted...... from the sensors. In this paper, we define the concept of sensor databases mixing stored data represented as relations and sensor data represented as time series. Each long-running query formulated over a sensor database defines a persistent view, which is maintained during a given time interval. We...... also describe the design and implementation of the COUGAR sensor database system....
Development of Soft Tactile Sensor for Prostatic Palpation Diagnosis: Sensor Structure Design and Analysis
Directory of Open Access Journals (Sweden)
Zhongwei Jiang
Full Text Available This paper is concerned with the development of a palpation probe for assessment of prostatic cancer and hypertrophy. The sensor is constructed by layering two polivinylidene fluoride (PVDF films into soft material layers such as vulcanized rubber and sponge rubber sheets. Since the contact condition between the sensor and soft objects influences the sensor output significantly, the improvement of its sensitivity is investigated by design of an attachment covered over the sensor surface. In this report, the theoretical model of the sensor and the design of the attachment are presented and the attachment is validated for soft substances due to experimental investigation. Finally, a compact probe developed for clinical testing is presented and the data obtained from the patients are treated by the wavelet transform for de-noising. Some representative clinical data show that the sensor could be a useful tool for group medical checkup on prostatic cancer and hypertrophy.
Optimum distributed detection of weak signals in dependent sensors
Blum, Rick S.; Kassam, Saleem A.
The extension of classical locally optimum (LO) detection results to the case of distributed detection with dependent sensors is considered. The necessary conditions are presented for the LO distributed sensor detector designs and fusion rule for an N sensor parallel distributed detection system with dependent sensor observations. Specific solutions are obtained for a random signal in additive noise detection problem with two sensors. Letting f be the noise probability density function (pdf), these solutions indicate that the LO sensor detector nonlinearities, in general, contain a term proportional to f-prime/f. The importance of this term varies with the additive noise pdf and the false alarm probability. LO solutions are presented for finite sample sizes, and the LO solutions are discussed in the asymptotic case. The results are extended to yield the form of the solutions for the N sensor LO random signal distribution problem, which yields expected generalizations of the two sensor results.
Flexible Sensors for Pressure Therapy: Effect of Substrate Curvature and Stiffness on Sensor Performance.
Khodasevych, Iryna; Parmar, Suresh; Troynikov, Olga
Flexible pressure sensors are increasingly being used in medical and non-medical applications, and particularly in innovative health monitoring. Their efficacy in medical applications such as compression therapy depends on the accuracy and repeatability of their output, which in turn depend on factors such as sensor type, shape, pressure range, and conformability of the sensor to the body surface. Numerous researchers have examined the effects of sensor type and shape, but little information is available on the effect of human body parameters such as support surfaces' curvature and the stiffness of soft tissues on pressure sensing performance. We investigated the effects of body parameters on the performance of pressure sensors using a custom-made human-leg-like test setup. Pressure sensing parameters such as accuracy, drift and repeatability were determined in both static (eight hours continuous pressure) and dynamic (10 cycles of pressure application of 30 s duration) testing conditions. The testing was performed with a focus on compression therapy application for venous leg ulcer treatments, and was conducted in a low-pressure range of 20-70 mmHg. Commercially available sensors manufactured by Peratech and Sensitronics were used under various loading conditions to determine the influence of stiffness and curvature. Flat rigid, flat soft silicone and three cylindrical silicone surfaces of radii of curvature of 3.5 cm, 5.5 cm and 6.5 cm were used as substrates under the sensors. The Peratech sensor averaged 94% accuracy for both static and dynamic measurements on all substrates; the Sensitronics sensor averaged 88% accuracy. The Peratech sensor displayed moderate variations and the Sensitronics sensor large variations in output pressure readings depending on the underlying test surface, both of which were reduced markedly by individual pressure calibration for surface type. Sensor choice and need for calibration to surface type are important considerations for
Formal reconstruction of attack scenarios in mobile ad hoc and sensor networks
Directory of Open Access Journals (Sweden)
Rekhis Slim
Full Text Available Abstract Several techniques of theoretical digital investigation are presented in the literature but most of them are unsuitable to cope with attacks in wireless networks, especially in Mobile Ad hoc and Sensor Networks (MASNets. In this article, we propose a formal approach for digital investigation of security attacks in wireless networks. We provide a model for describing attack scenarios in a wireless environment, and system and network evidence generated consequently. The use of formal approaches is motivated by the need to avoid ad hoc generation of results that impedes the accuracy of analysis and integrity of investigation. We develop an inference system that integrates the two types of evidence, handles incompleteness and duplication of information in them, and allows possible and provable actions and attack scenarios to be generated. To illustrate the proposal, we consider a case study dealing with the investigation of a remote buffer overflow attack.
High temperature sensors for exhaust diagnosis
Energy Technology Data Exchange (ETDEWEB)
Svenningstorp, Henrik
One of the largest problems that we will have to deal with on this planet this millennium is to stop the pollution of our environment. In many of the ongoing works to reduce toxic emissions, gas sensors capable of enduring rough environments and high temperatures, would be a great tool. The different applications where sensors like this would be useful vary between everything from online measurement in the paper industry and food industry to measurement in the exhaust pipe of a car. In my project we have tested Schottky diodes and MlSiCFET sensor as gas sensors operating at high temperatures. The measurement condition in the exhaust pipe of a car is extremely tough, not only is the temperature high and the different gases quite harmful, there are also a lot of particles that can affect the sensors in an undesirable way. In my project we have been testing Schottky diodes and MlSiCFET sensors based on SiC as high temperature sensors, both in the laboratory with simulated exhaust and after a real engine. In this thesis we conclude that these sensors can work in the hostile environment of an engines exhaust. It is shown that when measuring in a gas mixture with a fixed I below one, where the I-value is controlled by the O{sub 2} concentration, a sensor with a catalytic gate metal as sensitive material respond more to the increased O{sub 2} concentration than the increased HC concentration when varying the two correspondingly. A number of different sensors have been tested in simulated exhaust towards NO{sub x}. It was shown that resistivity changes in the thin gate metal influenced the gas response. Tests have been performed where sensors were a part of a SCR system with promising results concerning NH{sub 3} sensitivity. With a working temperature of 300 deg C there is no contamination of the metal surface.
Agrawal, Dharma Prakash
This inspiring textbook provides an introduction to wireless technologies for sensors, explores potential use of sensors for numerous applications, and utilizes probability theory and mathematical methods as a means of embedding sensors in system design. It discusses the need for synchronization and underlying limitations, inter-relation between given coverage and connectivity to number of sensors needed, and the use of geometrical distance to determine location of the base station for data collection and explore use of anchor nodes for relative position determination of sensors. The book explores energy conservation, communication using TCP, the need for clustering and data aggregation, and residual energy determination and energy harvesting. It covers key topics of sensor communication like mobile base stations and relay nodes, delay-tolerant sensor networks, and remote sensing and possible applications. The book defines routing methods and do performance evaluation for random and regular sensor topology an...
Air Sensor Toolbox provides information to citizen scientists, researchers and developers interested in learning more about new lower-cost compact air sensor technologies and tools for measuring air quality.
Performance of an Ultrasonic Ranging Sensor in Apple Tree Canopies
Directory of Open Access Journals (Sweden)
Alexandre Escolà
Full Text Available Electronic canopy characterization is an important issue in tree crop management. Ultrasonic and optical sensors are the most used for this purpose. The objective of this work was to assess the performance of an ultrasonic sensor under laboratory and field conditions in order to provide reliable estimations of distance measurements to apple tree canopies. To this purpose, a methodology has been designed to analyze sensor performance in relation to foliage ranging and to interferences with adjacent sensors when working simultaneously. Results show that the average error in distance measurement using the ultrasonic sensor in laboratory conditions is ±0.53 cm. However, the increase of variability in field conditions reduces the accuracy of this kind of sensors when estimating distances to canopies. The average error in such situations is ±5.11 cm. When analyzing interferences of adjacent sensors 30 cm apart, the average error is ±17.46 cm. When sensors are separated 60 cm, the average error is ±9.29 cm. The ultrasonic sensor tested has been proven to be suitable to estimate distances to the canopy in field conditions when sensors are 60 cm apart or more and could, therefore, be used in a system to estimate structural canopy parameters in precision horticulture.
Performance of an Ultrasonic Ranging Sensor in Apple Tree Canopies
Escolà, Alexandre; Planas, Santiago; Rosell, Joan Ramon; Pomar, Jesús; Camp, Ferran; Solanelles, Francesc; Gracia, Felip; Llorens, Jordi; Gil, Emilio
Electronic canopy characterization is an important issue in tree crop management. Ultrasonic and optical sensors are the most used for this purpose. The objective of this work was to assess the performance of an ultrasonic sensor under laboratory and field conditions in order to provide reliable estimations of distance measurements to apple tree canopies. To this purpose, a methodology has been designed to analyze sensor performance in relation to foliage ranging and to interferences with adjacent sensors when working simultaneously. Results show that the average error in distance measurement using the ultrasonic sensor in laboratory conditions is ±0.53 cm. However, the increase of variability in field conditions reduces the accuracy of this kind of sensors when estimating distances to canopies. The average error in such situations is ±5.11 cm. When analyzing interferences of adjacent sensors 30 cm apart, the average error is ±17.46 cm. When sensors are separated 60 cm, the average error is ±9.29 cm. The ultrasonic sensor tested has been proven to be suitable to estimate distances to the canopy in field conditions when sensors are 60 cm apart or more and could, therefore, be used in a system to estimate structural canopy parameters in precision horticulture. PMID:22163749
Performance of an ultrasonic ranging sensor in apple tree canopies.
Escolà, Alexandre; Planas, Santiago; Rosell, Joan Ramon; Pomar, Jesús; Camp, Ferran; Solanelles, Francesc; Gracia, Felip; Llorens, Jordi; Gil, Emilio
Electronic canopy characterization is an important issue in tree crop management. Ultrasonic and optical sensors are the most used for this purpose. The objective of this work was to assess the performance of an ultrasonic sensor under laboratory and field conditions in order to provide reliable estimations of distance measurements to apple tree canopies. To this purpose, a methodology has been designed to analyze sensor performance in relation to foliage ranging and to interferences with adjacent sensors when working simultaneously. Results show that the average error in distance measurement using the ultrasonic sensor in laboratory conditions is ±0.53 cm. However, the increase of variability in field conditions reduces the accuracy of this kind of sensors when estimating distances to canopies. The average error in such situations is ±5.11 cm. When analyzing interferences of adjacent sensors 30 cm apart, the average error is ±17.46 cm. When sensors are separated 60 cm, the average error is ±9.29 cm. The ultrasonic sensor tested has been proven to be suitable to estimate distances to the canopy in field conditions when sensors are 60 cm apart or more and could, therefore, be used in a system to estimate structural canopy parameters in precision horticulture.
Biomedical Sensors of Ionizing Radiation
Pani, S; Speller, R; Royle, G; Olivo, A
Sensors Technology Series Editor-in-Chief's Preface vii Preface ix 1 Biomedical Sensors: Temperature Sensor ... G. Kim Prisk 4 Biomedical Sensors of Ionizing Radiation 129 Robert Speller, Alessandro Olivo, Silvia Pani, and Gary Royle 5 ...
Energy Technology Data Exchange (ETDEWEB)
Ted Quinn; Jerry Mauck; Richard Bockhorst; Ken Thomas
The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy, reliability, availability, and maintainability. This report demonstrates these benefits in direct comparisons of digital and analog sensor applications. It also addresses the qualification issues that must be addressed in the application of digital sensor technology.
Shakkottai, Parthasarathy; Kwack, Eug Y.; Venkateshan, Shakkottai
Industrial humidity sensor measures volume fraction of water in air via its effect on speed of sound. Only portion of sensor exposed to sensed atmosphere is pair of stainless-steel tubes, one containing dry air and other containing moist air. Counters measure intervals between reflected pulses. Sensor rugged enough for use in harsh environments like those used to control drying of paper in paper mills, where most humidity sensors do not survive.
Effects of wastewater and combined sewer overflows on water quality in the Blue River basin, Kansas City, Missouri and Kansas, July 1998-October 2000
Wilkison, Donald H.; Armstrong, Daniel J.; Blevins, Dale W.
Samples were collected from 16 base-flow events and a minimum of 10 stormflow events between July 1998 and October 2000 to characterize the effects of wastewater and combined sewer overflows on water quality in the Blue River Basin, Kansas City, Missouri and Kansas. Waterquality effects were determined by analysis of nutrients, chloride, chemical and biochemical oxygen demand, and suspended sediment samples from three streams (Blue River, Brush Creek, and Indian Creek) in the basin as well as the determination of a suite of compounds known to be indicative of wastewater including antioxidants, caffeine, detergent metabolites, antimicrobials, and selected over-the-counter and prescription pharmaceuticals. Constituent loads were determined for both hydrologic regimes and a measure of the relative water-quality impact of selected stream reaches on the Blue River and Brush Creek was developed. Genetic fingerprint patterns of Escherichia coli bacteria from selected stream samples were compared to a data base of knownsource patterns to determine possible sources of bacteria. Water quality in the basin was affected by wastewater during both base flows and stormflows; however, there were two distinct sources that contributed to these effects. In the Blue River and Indian Creek, the nearly continuous discharge of treated wastewater effluent was the primary source of nutrients, wastewater indicator compounds, and pharmaceutical compounds detected in stream samples. Wastewater inputs into Brush Creek were largely the result of intermittent stormflow events that triggered the overflow of combined storm and sanitary sewers, and the subsequent discharge of untreated wastewater into the creek. A portion of the sediment, organic matter, and associated constituents from these events were trapped by a series of impoundments constructed along Brush Creek where they likely continued to affect water quality during base flow. Concentrations and loads of most wastewater constituents in
Optical sensors for harsh environment applications
Sharma, R.; Maity, S.; Bekal, A.; Vartak, S.; Sridharan, A. K.; Mitra, C.
The development of a harsh environment ammonia slip sensor based on tunable diode laser absorption spectroscopy is presented. A hybrid optical sensor design, through combination of wavelength modulation spectroscopy (WMS) and alignment control, is proposed as an approach towards reliable in-situ measurements in misalignment prone harsh environments. 1531.59 nm, 1553.4 nm and 1555.56 nm are suggested as possible absorption lines for trace ammonia measurement (gas turbine exhaust conditions. Design and performance of the alignment control system are presented in detail. Effect of misalignment related measurement degradation is investigated and significant improvement in measurement fidelity is demonstrated through the use of the hybrid optical sensor design.
Laser sensor system documentation.
Phase 1 of TxDOT Project 0-6873, True Road Surface Deflection Measuring Device, developed a : laser sensor system based on several sensors mounted on a rigid beam. : This sensor system remains with CTR currently, as the project is moving into Phase 2...
Directory of Open Access Journals (Sweden)
Fabrizio Lamberti
Full Text Available Sensors are becoming ubiquitous in all areas of science, technology, and society. In this Special Issue on "Sensors for Entertainment", developments in progress and the current state of application scenarios for sensors in the field of entertainment is explored.
Bergveld, Piet
This paper describes the organization and the research programme of the Sensor and Actuator (S&A) Research Unit of the University of Twente, Enschede, the Netherlands. It includes short descriptions of all present projects concerning: micromachined mechanical sensors and actuators, optical sensors,
Elwenspoek, Michael Curt
A review is given on sensors fabricated by silicon micromachining technology using the thermal domain for the measurement of fluid flow. Attention is paid especially to performance and geometry of the sensors. Three basic types of thermal flow sensors are discussed: anemometers, calorimetric flow
Energy Technology Data Exchange (ETDEWEB)
Sheen, S.H.; Raptis, A.C.; Moscynski, M.J.
This report is an introduction to the field of automotive vehicle sensors. It contains a prototype data base for companies working in automotive vehicle sensors, as well as a prototype data base for automotive vehicle sensors. A market analysis is also included.
Directory of Open Access Journals (Sweden)
Javad MOKHBERY
Full Text Available This article describes the importance of sensor verification. It also describes the benefits of a portable sensor verification system and how it can be an essential tool that compliments any program in which sensors are used for control manufacturing or during critical testing.
Multifuctional integrated sensors (MFISES).
Energy Technology Data Exchange (ETDEWEB)
Homeijer, Brian D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roozeboom, Clifton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Many emerging IoT applications require sensing of multiple physical and environmental parameters for: completeness of information, measurement validation, unexpected demands, improved performance. For example, a typical outdoor weather station measures temperature, humidity, barometric pressure, light intensity, rainfall, wind speed and direction. Existing sensor technologies do not directly address the demand for cost, size, and power reduction in multi-paramater sensing applications. Industry sensor manufacturers have developed integrated sensor systems for inertial measurements that combine accelerometers, gyroscopes, and magnetometers, but do not address environmental sensing functionality. In existing research literature, a technology gap exists between the functionality of MEMS sensors and the real world applications of the sensors systems.
Wright, Joel; Gibson, Christopher; Bergamaschi, Flavio; Marcus, Kelvin; Pham, Tien; Pressley, Ryan; Verma, Gunjan
The diverse sensor types and networking technologies commonly used in fielded sensro networks provide a unique set of challenges [1] in the areas of sensor identification, interoperability, and sensor data consumability. The ITA Senor Fabric is a middleware infrastructure - developed as part of the International Technology Alliance (ITA)[2] in Network and Information Science - that addresses these challenges by providing unified access to, and management of, sensor networks. The Fabric spans the network from command and control, through forward operating bases, and out to mobile forces and fielded sensors, maximizing the availability and utility of intelligence information to users.
Ultrahigh Temperature Capacitive Pressure Sensor
Harsh, Kevin
Robust, miniaturized sensing systems are needed to improve performance, increase efficiency, and track system health status and failure modes of advanced propulsion systems. Because microsensors must operate in extremely harsh environments, there are many technical challenges involved in developing reliable systems. In addition to high temperatures and pressures, sensing systems are exposed to oxidation, corrosion, thermal shock, fatigue, fouling, and abrasive wear. In these harsh conditions, sensors must be able to withstand high flow rates, vibration, jet fuel, and exhaust. In order for existing and future aeropropulsion turbine engines to improve safety and reduce cost and emissions while controlling engine instabilities, more accurate and complete sensor information is necessary. High-temperature (300 to 1,350 C) capacitive pressure sensors are of particular interest due to their high measurement bandwidth and inherent suitability for wireless readout schemes. The objective of this project is to develop a capacitive pressure sensor based on silicon carbon nitride (SiCN), a new class of high-temperature ceramic materials, which possesses excellent mechanical and electric properties at temperatures up to 1,600 C.
Elastic Wave Measurement Using a MEMS AE Sensor
Directory of Open Access Journals (Sweden)
Takahiro Omori
Full Text Available In recent years, with the continuing progress of aging social infrastructures such as bridges and tunnels, there has been high demand for the assessment of deterioration of their performance and conditions. Since current inspection methods for those structures have mainly relied on human resources, it is important to reduce their increasing maintenance cost. One of the key methods for achieving effective maintenance without expensive human costs is to use sensors to discriminate between healthy and unhealthy conditions. In this paper, a MEMS (micro electro mechanical systems wideband frequency sensor, which is referred to as a super acoustic (SA sensor, is evaluated through the pencil lead break (PLB test. Due to its wideband frequency characteristics, the SA sensor is expected to be a promising alternative to the existing vibration sensors, including acoustic emission (AE sensors. Several PLB signals were generated on an aluminum plate (5 mm thick, and propagating Lamb waves were detected by both AE and SA sensors. SA sensors were able to identify the location of PLB sources on the plate by measuring time differences between each sensor. By comparing the wave spectrums of both the AE and SA sensors analyzed by wavelet transform, the applicability of SA sensor for AE measurement is verified.
A Resilient Condition Assessment Monitoring System
Energy Technology Data Exchange (ETDEWEB)
Humberto Garcia; Wen-Chiao Lin; Semyon M. Meerkov
An architecture and supporting methods are presented for the implementation of a resilient condition assessment monitoring system that can adaptively accommodate both cyber and physical anomalies to a monitored system under observation. In particular, the architecture includes three layers: information, assessment, and sensor selection. The information layer estimates probability distributions of process variables based on sensor measurements and assessments of the quality of sensor data. Based on these estimates, the assessment layer then employs probabilistic reasoning methods to assess the plant health. The sensor selection layer selects sensors so that assessments of the plant condition can be made within desired time periods. Resilient features of the developed system are then illustrated by simulations of a simplified power plant model, where a large portion of the sensors are under attack.
Sensor mount assemblies and sensor assemblies
Miller, David H [Redondo Beach, CA
Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and the tooth is formed on the second end of the first finger.
Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Laboratory
Brewster, L.; Johnston, A.; Howard, R.; Mitchell, J.; Cryan, S.
) using the FRL's 6-DOF gantry system, called the Dynamic Overhead Target System (DOTS). The target vehicle for "docking" in the laboratory was a mockup that was representative of the proposed CEV docking system, with added retroreflectors for the AVGS. The multi-sensor test configuration used 35 open-loop test trajectories covering three major objectives: (1) sensor characterization trajectories designed to test a wide range of performance parameters; (2) CEV-specific trajectories designed to test performance during CEV-like approach and departure profiles; and (3) sensor characterization tests designed for evaluating sensor performance under more extreme conditions as might be induced during a spacecraft failure or during contingency situations. This paper describes the test development, test facility, test preparations, test execution, and test results of the multi-sensor series of trajectories.
Wireless Biological Electronic Sensors.
Cui, Yue
The development of wireless biological electronic sensors could open up significant advances for both fundamental studies and practical applications in a variety of areas, including medical diagnosis, environmental monitoring, and defense applications. One of the major challenges in the development of wireless bioelectronic sensors is the successful integration of biosensing units and wireless signal transducers. In recent years, there are a few types of wireless communication systems that have been integrated with biosensing systems to construct wireless bioelectronic sensors. To successfully construct wireless biological electronic sensors, there are several interesting questions: What types of biosensing transducers can be used in wireless bioelectronic sensors? What types of wireless systems can be integrated with biosensing transducers to construct wireless bioelectronic sensors? How are the electrical sensing signals generated and transmitted? This review will highlight the early attempts to address these questions in the development of wireless biological electronic sensors.
DEFF Research Database (Denmark)
Andersen, Per Dannemand; Jørgensen, Birte Holst; Rasmussen, Birgitte
, robustness, dispensability, and the abilityto be self-calibrating. Future sensors are expected to be integrated systems with multiple applications. The market sectors most influenced by new sensor technology change from topic to topic. But a general conclusion is that health care is the marketsector most......The Sensor Technology Center A/S (STC) in co-operation with Risoe National Laboratory has carried out a sensor technology foresight in order to strengthen a strategic outlook on sensor technology. The technology foresight (with a timeframe of 2000 to2015) has been performed in the period October...... 2000 - September 2001. The conclusions of the sensor technology report are based on 1) a scanning of existing forward looking literature on sensor technology, 2) a number of workshops with Danish andinternational participants and 3) an international survey with 174 respondents. Half of the respondents...
Energy Technology Data Exchange (ETDEWEB)
Galambos, Paul C.; Crenshaw, Thomas B.; Nishida, Erik E.; Burnett, Damon J.; Lantz, Jeffrey W.
The various technologies presented herein relate to a sensor for measurement of high forces and/or high load shock rate(s), whereby the sensor utilizes silicon as the sensing element. A plate of Si can have a thinned region formed therein on which can be formed a number of traces operating as a Wheatstone bridge. The brittle Si can be incorporated into a layered structure comprising ductile and/or compliant materials. The sensor can have a washer-like configuration which can be incorporated into a nut and bolt configuration, whereby tightening of the nut and bolt can facilitate application of a compressive preload upon the sensor. Upon application of an impact load on the bolt, the compressive load on the sensor can be reduced (e.g., moves towards zero-load), however the magnitude of the preload can be such that the load on the sensor does not translate to tensile stress being applied to the sensor.
DEFF Research Database (Denmark)
The present invention relates to an all-optical sensor utilizing effective index modulation of a waveguide and detection of a wavelength shift of reflected light and a force sensing system accommodating said optical sensor. One embodiment of the invention relates to a sensor system comprising...... at least one multimode light source, one or more optical sensors comprising a multimode sensor optical waveguide accommodating a distributed Bragg reflector, at least one transmitting optical waveguide for guiding light from said at least one light source to said one or more multimode sensor optical...... waveguides, a detector for measuring light reflected from said Bragg reflector in said one or more multimode sensor optical waveguides, and a data processor adapted for analyzing variations in the Bragg wavelength of at least one higher order mode of the reflected light....
Impact of river overflowing on trace element contamination of volcanic soils in south Italy: part II. Soil biological and biochemical properties in relation to trace element speciation.
D'Ascoli, R; Rao, M A; Adamo, P; Renella, G; Landi, L; Rutigliano, F A; Terribile, F; Gianfreda, L
The effect of heavy metal contamination on biological and biochemical properties of Italian volcanic soils was evaluated in a multidisciplinary study, involving pedoenvironmental, micromorphological, physical, chemical, biological and biochemical analyses. Soils affected by recurring river overflowing, with Cr(III)-contaminated water and sediments, and a non-flooded control soil were analysed for microbial biomass, total and active fungal mycelium, enzyme activities (i.e., FDA hydrolase, dehydrogenase, beta-glucosidase, urease, arylsulphatase, acid phosphatase) and bacterial diversity (DGGE characterisation). Biological and biochemical data were related with both total and selected fractions of Cr and Cu (the latter deriving from agricultural chemical products) as well as with total and extractable organic C. The growth and activity of soil microbial community were influenced by soil organic C content rather than Cu or Cr contents. In fact, positive correlations between all studied parameters and organic C content were found. On the contrary, negative correlations were observed only between total fungal mycelium, dehydrogenase, arylsulphatase and acid phosphatase activities and only one Cr fraction (the soluble, exchangeable and carbonate bound). However, total Cr content negatively affected the eubacterial diversity but it did not determine changes in soil activity, probably because of the redundancy of functions within species of soil microbial community. On the other hand, expressing biological and biochemical parameters per unit of total organic C, Cu pollution negatively influenced microbial biomass, fungal mycelium and several enzyme activities, confirming soil organic matter is able to mask the negative effects of Cu on microbial community.
A Sensor System for Detection of Hull Surface Defects
Directory of Open Access Journals (Sweden)
Juan Suardíaz
Full Text Available This paper presents a sensor system for detecting defects in ship hull surfaces. The sensor was developed to enable a robotic system to perform grit blasting operations on ship hulls. To achieve this, the proposed sensor system captures images with the help of a camera and processes them in real time using a new defect detection method based on thresholding techniques. What makes this method different is its efficiency in the automatic detection of defects from images recorded in variable lighting conditions. The sensor system was tested under real conditions at a Spanish shipyard, with excellent results.
Impaired glycogen synthesis causes metabolic overflow reactions and affects stress responses in the cyanobacterium Synechocystis sp. PCC 6803.
Gründel, Marianne; Scheunemann, Ramon; Lockau, Wolfgang; Zilliges, Yvonne
The biosynthesis of glycogen or starch is one of the main strategies developed by living organisms for the intracellular storage of carbon and energy. In phototrophic organisms, such polyglucans accumulate due to carbon fixation during photosynthesis and are used to provide maintenance energy for cell integrity, function and viability in dark periods. Moreover, it is assumed that glycogen enables cyanobacteria to cope with transient starvation conditions, as observed in most micro-organisms. Here, glycogen accumulates when an appropriate carbon source is available in sufficient amounts but growth is inhibited by lack of other nutrients. In this study, the role of glycogen in energy and carbon metabolism of phototrophic cyanobacteria was first analysed via a comparative physiological and metabolic characterization of knockout mutants defective in glycogen synthesis. We first proved the role of glycogen as a respiratory substrate in periods of darkness, the role of glycogen as a reserve to survive starvation periods such as nitrogen depletion and the role of glycogen synthesis as an ameliorator of carbon excess conditions in the model organism Synechocystis sp. PCC 6803. We provide striking new insights into the complex carbon and nitrogen metabolism of non-diazotrophic cyanobacteria: a phenotype of sensitivity to photomixotrophic conditions and of reduced glucose uptake, a non-bleaching phenotype based on an impaired acclimation response to nitrogen depletion and furthermore a phenotype of energy spilling. This study shows that the analysis of deficiencies in glycogen metabolism is a valuable tool for the identification of metabolic regulatory principles and signals.
Prototyping an Operational System with Multiple Sensors for Pasture Monitoring
Directory of Open Access Journals (Sweden)
Tim Wark
Full Text Available Combining multiple proximal sensors within a wireless sensor network (WSN enhances our capacity to monitor vegetation, compared to using a single sensor or non-networked setup. Data from sensors with different spatial and temporal characteristics can provide complementary information. For example, point-based sensors such as multispectral sensors which monitor at high temporal frequency but, at a single point, can be complemented by array-based sensors such as digital cameras which have greater spatial resolution but may only gather data at infrequent intervals. In this article we describe the successful deployment of a prototype system for using multiple proximal sensors (multispectral sensors and digital cameras for monitoring pastures. We show that there are many technical issues involved in such a deployment, and we share insights relevant for other researchers who may consider using WSNs for an operational deployment for pasture monitoring under often difficult environmental conditions. Although the sensors and infrastructure are important, we found that other issues arise and that an end-to-end workflow is an essential part of effectively capturing, processing and managing the data from a WSN. Our deployment highlights the importance of testing and ongoing monitoring of the entire workflow to ensure the quality of data captured. We demonstrate that the combination of different sensors enhances our ability to identify sensor problems necessary to collect accurate data for pasture monitoring.
HEAT Sensor: Harsh Environment Adaptable Thermionic Sensor
Energy Technology Data Exchange (ETDEWEB)
Limb, Scott J. [Palo Alto Research Center, Palo Alto, CA (United States)
This document is the final report for the "HARSH ENVIRONMENT ADAPTABLE THERMIONIC SENSOR" project under NETL's Crosscutting contract DE-FE0013062. This report addresses sensors that can be made with thermionic thin films along with the required high temperature hermetic packaging process. These sensors can be placed in harsh high temperature environments and potentially be wireless and self-powered.
Directory of Open Access Journals (Sweden)
Rudy Susanto
Full Text Available A car driver often had trouble to park his car a narrow location, caused by a narrow parking area on the wane.Also, cars had often crashed the electric pillar or scratched the car on the wall while retreat. The problem was the driverdidn't know condition behind vehicle because of limited of view. The research aimed to make a system that can easily helpdriver in parking his car, by using of ultrasonic parking sensor. The method used in sensor scheme parks is ultrasonicisensor to detect and measure car and balk distance by utilising of 851 family microcontroller as the main system. Theresult indicates that ultrasonic censor effective deep measurement was on distance of 2 cm – 30 m. It is that enoughultrasonic censor is effective to be implemented on censor parks.
Kodzius, Rimantas
NOVELTY - The sensor has a microfluidic flow channel that is provided with an inlet port, an outlet port, and a detection chamber. The detection chamber is provided with a group of sensing electrodes (4) having a working electrode (8), a counter electrode (9), and a reference electrode (10). A flow sensor is configured to measure flow in the channel. A temperature sensor (6) is configured to measure temperature in the channel (3). An electrical connection is configured to connect the sensor to a sensing device. USE - Sensor for detecting metal such as toxic metal in sample such as clinical sample such as stool, saliva, sputum, bronchial lavage, urine, vaginal swab, nasal swab, biopsy, tissue, tears, breath, blood, serum, plasma, cerebrospinal fluid, peritoneal fluid, pleural fluid, pericardial fluid, joint fluid, and amniotic fluid, water sample, food sample, air sample, and soil sample (all claimed). ADVANTAGE - The sensor for use with the portable analytical instrument is configured for detection of metalsin samples. The sensor can provide the excellent solution for on-site metal detection, including heavy metal detection. The sensors can provide significant advantages in higher throughput, lower cost, at the same time being less labor intensive and less dependent on individual skills. The disposable design of the sensor, the enhanced reliability and repeatability of measurements can be obtained. The sensors can be widely applied in various industries. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a system for detecting metal in sample; and (2) a method for using sensor for detecting metal in sample. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the sensor prototype. Channel (3) Sensing electrodes (4) Temperature sensor (6) Working electrode (8) Counter electrode (9) Reference electrode (10)
MEMS direction finding acoustic sensor
Karunasiri, Gamani; Alves, Fabio; Swan, William
Conventional directional sound sensing systems employ an array of spatially separated microphones to achieve directivity. However, there are insects such as the Ormia ochracea fly that can determine the direction of sound using a miniature hearing organ much smaller than the wavelength of sound it detects. The fly's eardrums are coupled mechanically with a separation of only 0.5 mm and yet have a remarkable sensitivity to the direction of sound. The MEMS based sensor mimicking the fly's hearing system was fabricated using an SOI substrate with a 25 μm device layer. The sensor consists of two 1.5 mm x1.6 mm wings connected in the middle by a 2.7 mm x 30 μm bridge. The entire structure is connected to the substrate by two torsional legs at the center. The frequency response of the sensor showed two resonance frequencies at approximately 1.1 kHz (rocking) and 1.5 kHz (bending). The resonance at 1.1 kHz is due to rocking of the wings by twisting the legs and the other at 1.5 kHz is due to bending of the bridge. The response of the sensor was probed electronically using comb finger capacitors integrated to the edges of the wings and with the help of an MS3110 chip. A peak output voltage of about 9V/Pa was measured for sound incident normal to the device at the resonance frequency of the bending mode. The bearing of the incident sound under these conditions could be determined to within a few degrees. These findings indicate the potential use of the MEMS sensor to locate sound sources with high accuracy.
Strategy Developed for Selecting Optimal Sensors for Monitoring Engine Health
Sensor indications during rocket engine operation are the primary means of assessing engine performance and health. Effective selection and location of sensors in the operating engine environment enables accurate real-time condition monitoring and rapid engine controller response to mitigate critical fault conditions. These capabilities are crucial to ensure crew safety and mission success. Effective sensor selection also facilitates postflight condition assessment, which contributes to efficient engine maintenance and reduced operating costs. Under the Next Generation Launch Technology program, the NASA Glenn Research Center, in partnership with Rocketdyne Propulsion and Power, has developed a model-based procedure for systematically selecting an optimal sensor suite for assessing rocket engine system health. This optimization process is termed the systematic sensor selection strategy. Engine health management (EHM) systems generally employ multiple diagnostic procedures including data validation, anomaly detection, fault-isolation, and information fusion. The effectiveness of each diagnostic component is affected by the quality, availability, and compatibility of sensor data. Therefore systematic sensor selection is an enabling technology for EHM. Information in three categories is required by the systematic sensor selection strategy. The first category consists of targeted engine fault information; including the description and estimated risk-reduction factor for each identified fault. Risk-reduction factors are used to define and rank the potential merit of timely fault diagnoses. The second category is composed of candidate sensor information; including type, location, and estimated variance in normal operation. The final category includes the definition of fault scenarios characteristic of each targeted engine fault. These scenarios are defined in terms of engine model hardware parameters. Values of these parameters define engine simulations that generate
Localization and Tracking of Implantable Biomedical Sensors
Directory of Open Access Journals (Sweden)
Ilknur Umay
Full Text Available Implantable sensor systems are effective tools for biomedical diagnosis, visualization and treatment of various health conditions, attracting the interest of researchers, as well as healthcare practitioners. These systems efficiently and conveniently provide essential data of the body part being diagnosed, such as gastrointestinal (temperature, pH, pressure parameter values, blood glucose and pressure levels and electrocardiogram data. Such data are first transmitted from the implantable sensor units to an external receiver node or network and then to a central monitoring and control (computer unit for analysis, diagnosis and/or treatment. Implantable sensor units are typically in the form of mobile microrobotic capsules or implanted stationary (body-fixed units. In particular, capsule-based systems have attracted significant research interest recently, with a variety of applications, including endoscopy, microsurgery, drug delivery and biopsy. In such implantable sensor systems, one of the most challenging problems is the accurate localization and tracking of the microrobotic sensor unit (e.g., robotic capsule inside the human body. This article presents a literature review of the existing localization and tracking techniques for robotic implantable sensor systems with their merits and limitations and possible solutions of the proposed localization methods. The article also provides a brief discussion on the connection and cooperation of such techniques with wearable biomedical sensor systems.
Soil specific re-calibration of water content sensors for a field-scale sensor network
Gasch, Caley K.; Brown, David J.; Anderson, Todd; Brooks, Erin S.; Yourek, Matt A.
Obtaining accurate soil moisture data from a sensor network requires sensor calibration. Soil moisture sensors are factory calibrated, but multiple site specific factors may contribute to sensor inaccuracies. Thus, sensors should be calibrated for the specific soil type and conditions in which they will be installed. Lab calibration of a large number of sensors prior to installation in a heterogeneous setting may not be feasible, and it may not reflect the actual performance of the installed sensor. We investigated a multi-step approach to retroactively re-calibrate sensor water content data from the dielectric permittivity readings obtained by sensors in the field. We used water content data collected since 2009 from a sensor network installed at 42 locations and 5 depths (210 sensors total) within the 37-ha Cook Agronomy Farm with highly variable soils located in the Palouse region of the Northwest United States. First, volumetric water content was calculated from sensor dielectric readings using three equations: (1) a factory calibration using the Topp equation; (2) a custom calibration obtained empirically from an instrumented soil in the field; and (3) a hybrid equation that combines the Topp and custom equations. Second, we used soil physical properties (particle size and bulk density) and pedotransfer functions to estimate water content at saturation, field capacity, and wilting point for each installation location and depth. We also extracted the same reference points from the sensor readings, when available. Using these reference points, we re-scaled the sensor readings, such that water content was restricted to the range of values that we would expect given the physical properties of the soil. The re-calibration accuracy was assessed with volumetric water content measurements obtained from field-sampled cores taken on multiple dates. In general, the re-calibration was most accurate when all three reference points (saturation, field capacity, and wilting
Duff, Francis; McGarry, Donald; Zasada, David; Foote, Scott
The MITRE Sensor Layer Prototype is an initial design effort to enable every sensor to help create new capabilities through collaborative data sharing. By making both upstream (raw) and downstream (processed) sensor data visible, users can access the specific level, type, and quantities of data needed to create new data products that were never anticipated by the original designers of the individual sensors. The major characteristic that sets sensor data services apart from typical enterprise services is the volume (on the order of multiple terabytes) of raw data that can be generated by most sensors. Traditional tightly coupled processing approaches extract pre-determined information from the incoming raw sensor data, format it, and send it to predetermined users. The community is rapidly reaching the conclusion that tightly coupled sensor processing loses too much potentially critical information.1 Hence upstream (raw and partially processed) data must be extracted, rapidly archived, and advertised to the enterprise for unanticipated uses. The authors believe layered sensing net-centric integration can be achieved through a standardize-encapsulate-syndicateaggregate- manipulate-process paradigm. The Sensor Layer Prototype's technical approach focuses on implementing this proof of concept framework to make sensor data visible, accessible and useful to the enterprise. To achieve this, a "raw" data tap between physical transducers associated with sensor arrays and the embedded sensor signal processing hardware and software has been exploited. Second, we encapsulate and expose both raw and partially processed data to the enterprise within the context of a service-oriented architecture. Third, we advertise the presence of multiple types, and multiple layers of data through geographic-enabled Really Simple Syndication (GeoRSS) services. These GeoRSS feeds are aggregated, manipulated, and filtered by a feed aggregator. After filtering these feeds to bring just the type
Advanced Sensor Arrays and Packaging
Energy Technology Data Exchange (ETDEWEB)
Ryter, John Wesley [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Christopher J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ramaiyan, Kannan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brosha, Eric L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Novel sensor packaging elements were designed, fabricated, and tested in order to facilitate the transition of electrochemical mixed-potential sensors toward commercialization. Of the two designs completed, the first is currently undergoing field trials, taking direct measurements within vehicle exhaust streams, while the second is undergoing preliminary laboratory testing. The sensors' optimal operating conditions, sensitivity to hydrogen, and long-term baseline stability were also investigated. The sensing capabilities of lanthanum chromite (La0.8Sr0.2CrO3) and indium-doped tin oxide (ITO) working electrodes were compared, and the ITO devices were selected for pre-commercial field trials testing at a hydrogen fuel cell vehicle fueling station in California. Previous data from that fueling station were also analyzed, and the causes of anomalous baseline drift were identified.
Optical sensor for seawater salinity.
Huber, C; Klimant, I; Krause, C; Werner, T; Mayr, T; Wolfbeis, O S
An optical sensor for the measurement of salinity in seawater has been developed. It is based on a chloride-quenchable fluorescent probe (lucigenin) immobilized on a Nafion film. Two approaches for measuring salinity via chloride concentration are presented. In the first, a change in salinity corresponds to a change in the fluorescence intensity of lucigenin. In the second, the fluorescence intensity information is converted into a phase angle information by adding an inert phosphorescent reference luminophore (a ruthenium complex entrapped in poly(acrylonitrile) beads). Under these conditions, the chloride-dependent fluorescence intensity of lucigenin can be converted into a chloride-dependent fluorescence phase shift which serves as the analytical information. This scheme is referred to as dual lifetime referencing (DLR). The sensor was used to determine the salinity in seawater and brackish water of the North Sea.
DEFF Research Database (Denmark)
Leopold, Martin
. In addition, we present our results from porting the highly popular sensor network operating system TinyOS to a new and emerging system on a chip based platform. Moving the sensor network field towards the use of system-on- a-chip devices has large potential in terms of price and performance. We claim to have......This dissertation describes our efforts to improve sensor network performance evaluation and portability, within the context of the sensor network project Hogthrob. In Hogthrob, we faced the challenge of building an sensor network architecture for sow monitoring. This application has hard...... requirements on price and performance, and shows great potential for using sensor networks. Throughout the project we let the application requirements guide our design choices, leading us to push the technologies further to meet the specific goal of the application. In this dissertation, we attack two key...
Directory of Open Access Journals (Sweden)
Andrzej Bialas
Full Text Available The paper is focused on the security issues of sensors provided with processors and software and used for high-risk applications. Common IT related threats may cause serious consequences for sensor system users. To improve their robustness, sensor systems should be developed in a restricted way that would provide them with assurance. One assurance creation methodology is Common Criteria (ISO/IEC 15408 used for IT products and systems. The paper begins with a primer on the Common Criteria, and then a general security model of the intelligent sensor as an IT product is discussed. The paper presents how the security problem of the intelligent sensor is defined and solved. The contribution of the paper is to provide Common Criteria (CC related security design patterns and to improve the effectiveness of the sensor development process.
Energy Technology Data Exchange (ETDEWEB)
Ledebuhr, A.G. [Lawrence Livermore National Lab., CA (United States)
LLNL designed and built the suite of six miniaturized light-weight space-qualified sensors utilized in the Clementine mission. A major goal of the Clementine program was to demonstrate technologies originally developed for Ballistic Missile Defense Organization Programs. These sensors were modified to gather data from the moon. This overview presents each of these sensors and some preliminary on-orbit performance estimates. The basic subsystems of these sensors include optical baffles to reject off-axis stray light, light-weight ruggedized optical systems, filter wheel assemblies, radiation tolerant focal plane arrays, radiation hardened control and readout electronics and low mass and power mechanical cryogenic coolers for the infrared sensors. Descriptions of each sensor type are given along with design specifications, photographs and on-orbit data collected.
Energy Technology Data Exchange (ETDEWEB)
Artuso, M.; et al.,
Sensors play a key role in detecting both charged particles and photons for all three frontiers in Particle Physics. The signals from an individual sensor that can be used include ionization deposited, phonons created, or light emitted from excitations of the material. The individual sensors are then typically arrayed for detection of individual particles or groups of particles. Mounting of new, ever higher performance experiments, often depend on advances in sensors in a range of performance characteristics. These performance metrics can include position resolution for passing particles, time resolution on particles impacting the sensor, and overall rate capabilities. In addition the feasible detector area and cost frequently provides a limit to what can be built and therefore is often another area where improvements are important. Finally, radiation tolerance is becoming a requirement in a broad array of devices. We present a status report on a broad category of sensors, including challenges for the future and work in progress to solve those challenges.
Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R
A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.
Flexible magnetoimpedance sensor
Li, Bodong
Flexible magnetoimpedance (MI) sensors fabricated using a NiFe/Cu/NiFe tri-layer on Kapton substrate have been studied. A customized flexible microstrip transmission line was employed to investigate the MI sensors\\'s magnetic field and frequency responses and their dependence on the sensors\\'s deflection. For the first time, the impedance characteristic is obtained through reflection coefficient analysis over a wide range of frequencies from 0.1 MHz to 3 GHz and for deflections ranging from zero curvature to a radius of 7.2 cm. The sensor element maintains a high MI ratio of up to 90% and magnetic sensitivity of up to 9.2%/Oe over different bending curvatures. The relationship between the curvature and material composition is discussed based on the magnetostriction effect and stress simulations. The sensor\\'s large frequency range, simple fabrication process and high sensitivity provide a great potential for flexible electronics and wireless applications.
Bialas, Andrzej
The paper is focused on the security issues of sensors provided with processors and software and used for high-risk applications. Common IT related threats may cause serious consequences for sensor system users. To improve their robustness, sensor systems should be developed in a restricted way that would provide them with assurance. One assurance creation methodology is Common Criteria (ISO/IEC 15408) used for IT products and systems. The paper begins with a primer on the Common Criteria, and then a general security model of the intelligent sensor as an IT product is discussed. The paper presents how the security problem of the intelligent sensor is defined and solved. The contribution of the paper is to provide Common Criteria (CC) related security design patterns and to improve the effectiveness of the sensor development process. PMID:22315571
DEFF Research Database (Denmark)
Brauer, Peter
A model describing the fundamental working principle of the "ringcore fluxgate sensor" is derived. The model is solely based on geometrical and measurable magnetic properties of the sensor and from this a number of fluxgate phenomenon can be described and estimated. The sensitivity of ringcore...... fluxgate sensors is measured for a large variety of geometries and is for all measurements found to fall between two limits obtained by the fluxgate model. The model is used to explain the zero field odd harmonic output of the fluxgate sensor, called the "feedthrough". By assuming a non ideal sensor...... with spatially distributed magnetization, the model predicts feedthrough signals which exactly reflects the measured signals. The non-linearities in a feedback compensated ringcore fluxgate sensors, called the "transverse field effect", can also be explained by the model. Measurements on stress annealed...
A screen-printed flexible flow sensor
Moschos, A.; Syrovy, T.; Syrova, L.; Kaltsas, G.
A thermal flow sensor was printed on a flexible plastic substrate using exclusively screen-printing techniques. The presented device was implemented with custom made screen-printed thermistors, which allows simple, cost-efficient production on a variety of flexible substrates while maintaining the typical advantages of thermal flow sensors. Evaluation was performed for both static (zero flow) and dynamic conditions using a combination of electrical measurements and IR imaging techniques in order to determine important characteristics, such as temperature response, output repeatability, etc. The flow sensor was characterized utilizing the hot-wire and calorimetric principles of operation, while the preliminary results appear to be very promising, since the sensor was successfully evaluated and displayed adequate sensitivity in a relatively wide flow range.
Wireless Sensor Network for Forest Fire Detection
Directory of Open Access Journals (Sweden)
Emansa Hasri Putra
Full Text Available Forest fires are one of problems that threaten sustainability of the forest. Early prevention system for indications of forest fires is absolutely necessary. The extent of the forest to be one of the problems encountered in the forest condition monitoring. To overcome the problems of forest extent, designed a system of forest fire detection system by adopting the Wireless Sensor Network (WSN using multiple sensor nodes. Each sensor node has a microcontroller, transmitter/receiver and three sensors. Measurement method is performed by measuring the temperature, flame, the levels of methane, hydrocarbons, and CO2 in some forest area and the combustion of peat in a simulator. From results of measurements of temperature, levels of methane, a hydrocarbon gas and CO2 in an open area indicates there are no signs of fires due to the value of the temperature, methane, hydrocarbon gas, and CO2 is below the measurement in the space simulator.
Health-Enabled Smart Sensor Fusion Technology
Wang, Ray
A process was designed to fuse data from multiple sensors in order to make a more accurate estimation of the environment and overall health in an intelligent rocket test facility (IRTF), to provide reliable, high-confidence measurements for a variety of propulsion test articles. The object of the technology is to provide sensor fusion based on a distributed architecture. Specifically, the fusion technology is intended to succeed in providing health condition monitoring capability at the intelligent transceiver, such as RF signal strength, battery reading, computing resource monitoring, and sensor data reading. The technology also provides analytic and diagnostic intelligence at the intelligent transceiver, enhancing the IEEE 1451.x-based standard for sensor data management and distributions, as well as providing appropriate communications protocols to enable complex interactions to support timely and high-quality flow of information among the system elements.
Magnetic actuators and sensors
Brauer, John R
An accessible, comprehensive guide on magnetic actuators and sensors, this fully updated second edition of Magnetic Actuators and Sensors includes the latest advances, numerous worked calculations, illustrations, and real-life applications. Covering magnetics, actuators, sensors, and systems, with updates of new technologies and techniques, this exemplary learning tool emphasizes computer-aided design techniques, especially magnetic finite element analysis, commonly used by today's engineers. Detailed calculations, numerous illustrations, and discussions of discrepancies make this text an inva
Directory of Open Access Journals (Sweden)
Manel del Valle
Full Text Available This editorial summarizes and classifies the contributions presented by different authors to the special issue of the journal Sensors dedicated to Bioinspired Sensor Systems. From the coupling of sensor arrays or networks, plus computer processing abilities, new applications to mimic or to complement human senses are arising in the context of ambient intelligence. Principles used, and illustrative study cases have been presented permitting readers to grasp the current status of the field.
Kotovsky, Jack
A method for producing a contact stress sensor that includes one or more MEMS fabricated sensor elements, where each sensor element of includes a thin non-recessed portion, a recessed portion and a pressure sensitive element adjacent to the recessed portion. An electric circuit is connected to the pressure sensitive element. The circuit includes a pressure signal circuit element configured to provide a signal upon movement of the pressure sensitive element.
Kotovsky, Jack [Oakland, CA
A contact stress sensor includes one or more MEMS fabricated sensor elements, where each sensor element of includes a thin non-recessed portion, a recessed portion and a pressure sensitive element adjacent to the recessed portion. An electric circuit is connected to the pressure sensitive element. The circuit includes a thermal compensator and a pressure signal circuit element configured to provide a signal upon movement of the pressure sensitive element.
Transient multivariable sensor evaluation
Energy Technology Data Exchange (ETDEWEB)
Vilim, Richard B.; Heifetz, Alexander
A method and system for performing transient multivariable sensor evaluation. The method and system includes a computer system for identifying a model form, providing training measurement data, generating a basis vector, monitoring system data from sensor, loading the system data in a non-transient memory, performing an estimation to provide desired data and comparing the system data to the desired data and outputting an alarm for a defective sensor.
Fiber optic temperature sensor
Sawatari, Takeo (Inventor); Gaubis, Philip A. (Inventor)
A fiber optic temperature sensor uses a light source which transmits light through an optical fiber to a sensor head at the opposite end of the optical fiber from the light source. The sensor head has a housing coupled to the end of the optical fiber. A metallic reflective surface is coupled to the housing adjacent the end of the optical fiber to form a gap having a predetermined length between the reflective surface and the optical fiber. A detection system is also coupled to the optical fiber which determines the temperature at the sensor head from an interference pattern of light which is reflected from the reflective surface.
Kyung, Chong-Min; Yasuura, Hiroto; Liu, Yongpan
This book describes for readers technology used for effective sensing of our physical world and intelligent processing techniques for sensed information, which are essential to the success of Internet of Things (IoTs). The authors provide a multidisciplinary view of sensor technology from MEMS, biological, chemical, and electrical domains and showcase smart sensor systems in real applications including smart home, transportation, medical, environmental, agricultural, etc. Unlike earlier books on sensors, this book will provide a "global" view on smart sensors covering abstraction levels from device, circuit, systems, and algorithms. .
Improved Capacitive Liquid Sensor
Waldman, Francis A.
Improved capacitive sensor used to detect presence and/or measure thickness of layer of liquid. Electrical impedance or admittance of sensor measured at prescribed frequency, and thickness of liquid inferred from predetermined theoretical or experimental relationship between impedance and thickness. Sensor is basically a three-terminal device. Features interdigitated driving and sensing electrodes and peripheral coplanar ground electrode that reduces parasitic effects. Patent-pending because first to utilize ground plane as "shunting" electrode. System less expensive than infrared, microwave, or refractive-index systems. Sensor successfully evaluated in commercial production plants to characterize emulsions, slurries, and solutions.
Lansaw, John; Schmalzel, John; Figueroa, Jorge
John C. Stennis Space Center (SSC) provides rocket engine propulsion testing for NASA's space programs. Since the development of the Space Shuttle, every Space Shuttle Main Engine (SSME) has undergone acceptance testing at SSC before going to Kennedy Space Center (KSC) for integration into the Space Shuttle. The SSME is a large cryogenic rocket engine that uses Liquid Hydrogen (LH2) as the fuel. As NASA moves to the new ARES V launch system, the main engines on the new vehicle, as well as the upper stage engine, are currently base lined to be cryogenic rocket engines that will also use LH2. The main rocket engines for the ARES V will be larger than the SSME, while the upper stage engine will be approximately half that size. As a result, significant quantities of hydrogen will be required during the development, testing, and operation of these rocket engines.Better approaches are needed to simplify sensor integration and help reduce life-cycle costs. 1.Smarter sensors. Sensor integration should be a matter of "plug-and-play" making sensors easier to add to a system. Sensors that implement new standards can help address this problem; for example, IEEE STD 1451.4 defines transducer electronic data sheet (TEDS) templates for commonly used sensors such as bridge elements and thermocouples. When a 1451.4 compliant smart sensor is connected to a system that can read the TEDS memory, all information needed to configure the data acquisition system can be uploaded. This reduces the amount of labor required and helps minimize configuration errors. 2.Intelligent sensors. Data received from a sensor be scaled, linearized; and converted to engineering units. Methods to reduce sensor processing overhead at the application node are needed. Smart sensors using low-cost microprocessors with integral data acquisition and communication support offer the means to add these capabilities. Once a processor is embedded, other features can be added; for example, intelligent sensors can make
Power Consumption Considerations of GSM-connected Sensors in the AgroDat.hu Sensor Network
Directory of Open Access Journals (Sweden)
Gábor Paller
Full Text Available The number of large sensor systems is rapidly growing nowadays in many fields. Well-designed Big Data solutions are able to manage the enormous data flow and create real business benefits. One dynamically growing application area is precision farming. It requires robust and energy- efficient sensors, because the devices are placed outdoors, often in harsh conditions, and there is no power outlet "in the middle of a corn field". Power efficiency is in general one of the major themes of the Internet of Things (IoT. According to the IoT vision, embedded sensors send their data to processing units (either located near to the sensor or on some intermediate "gateway" device or in the cloud using heterogeneous transport networks. Some sensors employ short-range network like Bluetooth and some "gateway" device like a tablet. Other sensors directly connect to wide-area networks like cellular networks. This paper will analyze different communication patterns accomplished over GSM network from the viewpoint of the energy consumption of the sensor device with the assumption that the sensor is stationary. The measurements were done using two different GSM modems designed for embedded systems to ensure that the results represent a wider picture and not some implementation property of a particular GSM modem. Recommendations are given about the strategies applications should follow in order to minimize the energy consumption of their GSM subsystems.
Wearable sensors in healthcare and sensor-enhanced health information systems: all our tomorrows?
Marschollek, Michael; Gietzelt, Matthias; Schulze, Mareike; Kohlmann, Martin; Song, Bianying; Wolf, Klaus-Hendrik
Wearable sensor systems which allow for remote or self-monitoring of health-related parameters are regarded as one means to alleviate the consequences of demographic change. This paper aims to summarize current research in wearable sensors as well as in sensor-enhanced health information systems. Wearable sensor technologies are already advanced in terms of their technical capabilities and are frequently used for cardio-vascular monitoring. Epidemiologic predictions suggest that neuropsychiatric diseases will have a growing impact on our health systems and thus should be addressed more intensively. Two current project examples demonstrate the benefit of wearable sensor technologies: long-term, objective measurement under daily-life, unsupervised conditions. Finally, up-to-date approaches for the implementation of sensor-enhanced health information systems are outlined. Wearable sensors are an integral part of future pervasive, ubiquitous and person-centered health care delivery. Future challenges include their integration into sensor-enhanced health information systems and sound evaluation studies involving measures of workload reduction and costs.
Flight Tests on a Fiber Optic Temperature Sensor
Tuma, Margaret L.; Sawatari, Takeo; Lin, Yuping; Elam, Kristie A.
For aircraft engine control, one key parameter to detect on an airplane is the exhaust gas temperature (EGT). Presently, thermocouples are used to perform this measurement. These electrical sensors perform adequately; however, fully utilizing the benefits of optical sensors requires replacing electrical architectures with optical architectures. Part of this requires replacing electrical sensors with optical sensors, such as the EGT sensor chosen for these tests. The objective of the development and testing of this prototype sensor system was to determine the feasibility of operating an optical sensor in a hostile aircraft environment. The fiber optic sensor system was developed to measure temperatures from 20C to 600C in an aircraft environment and was utilized to monitor the EGT of an OV-10D aircraft engine. The sensor has successfully flown over 50 hours and proven to be immune to surface deterioration of the optical element (located inside the sensor head) and able to withstand and operate in normal and sustained severe flight conditions where forces on the airplane exceeded 4 g's. Potential commercial uses for this sensor include monitoring temperature for aeropropulsion system control, military vehicle and naval engine control, conventional and nuclear power plant monitoring and industrial plan monitoring where EMI issues are critical.
Comparing vector-based and Bayesian memory models using large-scale datasets: User-generated hashtag and tag prediction on Twitter and Stack Overflow.
Stanley, Clayton; Byrne, Michael D
The growth of social media and user-created content on online sites provides unique opportunities to study models of human declarative memory. By framing the task of choosing a hashtag for a tweet and tagging a post on Stack Overflow as a declarative memory retrieval problem, 2 cognitively plausible declarative memory models were applied to millions of posts and tweets and evaluated on how accurately they predict a user's chosen tags. An ACT-R based Bayesian model and a random permutation vector-based model were tested on the large data sets. The results show that past user behavior of tag use is a strong predictor of future behavior. Furthermore, past behavior was successfully incorporated into the random permutation model that previously used only context. Also, ACT-R's attentional weight term was linked to an entropy-weighting natural language processing method used to attenuate high-frequency words (e.g., articles and prepositions). Word order was not found to be a strong predictor of tag use, and the random permutation model performed comparably to the Bayesian model without including word order. This shows that the strength of the random permutation model is not in the ability to represent word order, but rather in the way in which context information is successfully compressed. The results of the large-scale exploration show how the architecture of the 2 memory models can be modified to significantly improve accuracy, and may suggest task-independent general modifications that can help improve model fit to human data in a much wider range of domains. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Impact of river overflowing on trace element contamination of volcanic soils in south Italy: Part II. Soil biological and biochemical properties in relation to trace element speciation
Energy Technology Data Exchange (ETDEWEB)
D' Ascoli, R. [Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli, via Vivaldi 43, 81100 Caserta (Italy)]. E-mail: firstname.lastname@example.com; Rao, M.A. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: firstname.lastname@example.com; Adamo, P. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: firstname.lastname@example.com; Renella, G. [Dipartimento di Scienza del Suolo e Nutrizione della Pianta, Universita degli Studi di Firenze, P.le delle Cascine 28, 50144 Firenze (Italy)]. E-mail: firstname.lastname@example.com; Landi, L. [Dipartimento di Scienza del Suolo e Nutrizione della Pianta, Universita degli Studi di Firenze, P.le delle Cascine 28, 50144 Firenze (Italy)]. E-mail: email@example.com; Rutigliano, F.A. [Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli, via Vivaldi 43, 81100 Caserta (Italy)]. E-mail: email@example.com; Terribile, F. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: firstname.lastname@example.com; Gianfreda, L. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: firstname.lastname@example.com
The effect of heavy metal contamination on biological and biochemical properties of Italian volcanic soils was evaluated in a multidisciplinary study, involving pedoenvironmental, micromorphological, physical, chemical, biological and biochemical analyses. Soils affected by recurring river overflowing, with Cr(III)-contaminated water and sediments, and a non-flooded control soil were analysed for microbial biomass, total and active fungal mycelium, enzyme activities (i.e., FDA hydrolase, dehydrogenase, {beta}-glucosidase, urease, arylsulphatase, acid phosphatase) and bacterial diversity (DGGE characterisation). Biological and biochemical data were related with both total and selected fractions of Cr and Cu (the latter deriving from agricultural chemical products) as well as with total and extractable organic C. The growth and activity of soil microbial community were influenced by soil organic C content rather than Cu or Cr contents. In fact, positive correlations between all studied parameters and organic C content were found. On the contrary, negative correlations were observed only between total fungal mycelium, dehydrogenase, arylsulphatase and acid phosphatase activities and only one Cr fraction (the soluble, exchangeable and carbonate bound). However, total Cr content negatively affected the eubacterial diversity but it did not determine changes in soil activity, probably because of the redundancy of functions within species of soil microbial community. On the other hand, expressing biological and biochemical parameters per unit of total organic C, Cu pollution negatively influenced microbial biomass, fungal mycelium and several enzyme activities, confirming soil organic matter is able to mask the negative effects of Cu on microbial community. - In studied soils organic C content resulted the principal factor influencing growth and activity of microbial community, with Cu and Cr contents having a lower relevance.
Xsense: a miniaturised multi-sensor platform for explosives detection
DEFF Research Database (Denmark)
Schmidt, Michael Stenbæk; Kostesha, Natalie; Bosco, Filippo
Realizing that no one sensing principle is perfect we set out to combine four fundamentally different sensing principles into one device. The reasoning is that each sensor will complement the others and provide redundancy under various environmental conditions. As each sensor can be fabricated us...
Energy-efficient and Heterogeneous Implantable Body Sensor Network
Karuppiah Ramachandran, Vignesh Raja; Meratnia, Nirvana; Havinga, Paul J.M.
Applications of body sensor networks (BSN) in health-care are growing rapidly. The number of implanted sensors used to accurately prognose and diagnose the medical conditions are increasing. The implanted medical devices (IMD), for example pace-makers are improvised for delivering patient centric
Laboratory and Field Tests of Ultrasonic Sensors for Precision Sprayers
Reliable function of sensors under rough field conditions is required for the development of variable-rate sprayers to deliver pest control agents to tree liners in ornamental nurseries. Two ultrasonic sensors were examined to identify how their durability and detection stability would be influenced...
Current-mode CMOS hybrid image sensor
Benyhesan, Mohammad Kassim
Digital imaging is growing rapidly making Complimentary Metal-Oxide-Semi conductor (CMOS) image sensor-based cameras indispensable in many modern life devices like cell phones, surveillance devices, personal computers, and tablets. For various purposes wireless portable image systems are widely deployed in many indoor and outdoor places such as hospitals, urban areas, streets, highways, forests, mountains, and towers. However, the increased demand on high-resolution image sensors and improved processing features is expected to increase the power consumption of the CMOS sensor-based camera systems. Increased power consumption translates into a reduced battery life-time. The increased power consumption might not be a problem if there is access to a nearby charging station. On the other hand, the problem arises if the image sensor is located in widely spread areas, unfavorable to human intervention, and difficult to reach. Given the limitation of energy sources available for wireless CMOS image sensor, an energy harvesting technique presents a viable solution to extend the sensor life-time. Energy can be harvested from the sun light or the artificial light surrounding the sensor itself. In this thesis, we propose a current-mode CMOS hybrid image sensor capable of energy harvesting and image capture. The proposed sensor is based on a hybrid pixel that can be programmed to perform the task of an image sensor and the task of a solar cell to harvest energy. The basic idea is to design a pixel that can be configured to exploit its internal photodiode to perform two functions: image sensing and energy harvesting. As a proof of concept a 40 x 40 array of hybrid pixels has been designed and fabricated in a standard 0.5 microm CMOS process. Measurement results show that up to 39 microW of power can be harvested from the array under 130 Klux condition with an energy efficiency of 220 nJ /pixel /frame. The proposed image sensor is a current-mode image sensor which has several
Potentiometric anion selective sensors
Antonisse, M.M.G.; Reinhoudt, David
In comparison with selective receptors (and sensors) for cationic species, work on the selective complexation and detection of anions is of more recent date. There are three important components for a sensor, a transducer element, a membrane material that separates the transducer element and the
Van Rosmalen, Peter; Schneider, Jan; Börner, Dirk
Sensors rapidly become available both for personal as well as scientific use. A wide range of applications exists for personal use e.g. safety in and around the house, sport, fitness and health. In this workshop we will explore how sensors are (can be) used in education. We start with an
Wireless Sensors Network (Sensornet)
Perotti, J.
The Wireless Sensor Network System presented in this paper provides a flexible reconfigurable architecture that could be used in a broad range of applications. It also provides a sensor network with increased reliability; decreased maintainability costs, and assured data availability by autonomously and automatically reconfiguring to overcome communication interferences.
DEFF Research Database (Denmark)
Plascencia, Alfredo; Stepán, Petr
The main contribution of this paper is to present a sensor fusion approach to scene environment mapping as part of a Sensor Data Fusion (SDF) architecture. This approach involves combined sonar array with stereo vision readings. Sonar readings are interpreted using probability density functions...
DEFF Research Database (Denmark)
The invention relates to a method for determining stretch values and movement of body parts, e.g. a foot, by analysing stretch data from a stretch sensor. By analysing data from the stretch sensor it is possible to determine stretch samples which are associated with particular motion phases...
Multiple Waveband Temperature Sensor (MWTS)
Bandara, Sumith V.; Gunapala, Sarath; Wilson, Daniel; Stirbl, Robert; Blea, Anthony; Harding, Gilbert
This slide presentation reviews the development of Multiple Waveband Temperature Sensor (MWTS). The MWTS project will result in a highly stable, monolithically integrated, high resolution infrared detector array sensor that records registered thermal imagery in four infrared wavebands to infer dynamic temperature profiles on a laser-irradiated ground target. An accurate surface temperature measurement of a target in extreme environments in a non-intrusive manner is required. The development challenge is to: determine optimum wavebands (suitable for target temperatures, nature of the targets and environments) to measure accurate target surface temperature independent of the emissivity, integrate simultaneously readable multiband Quantum Well Infrared Photodetectors (QWIPs) in a single monolithic focal plane array (FPA) sensor and to integrate the hardware/software and system calibration for remote temperature measurements. The charge was therefore to develop and demonstrate a multiband infrared imaging camera with the detectors simultaneously sensitive to multiple distinct color bands for front surface temperature measurements Wavelength ( m) measurements. Amongst the requirements are: that the measurement system will not affect target dynamics or response to the laser irradiation and that the simplest criterion for spectral band selection is to choose those practically feasible spectral bands that create the most contrast between the objects or scenes of interest in the expected environmental conditions. There is in the presentation a review of the modeling and simulation of multi-wave infrared temperature measurement and also a review of the detector development and QWIP capacities.
Directory of Open Access Journals (Sweden)
Michael Segal
Full Text Available Abstract: Ad-hoc networks of sensor nodes are in general semi-permanently deployed. However, the topology of such networks continuously changes over time, due to the power of some sensors wearing out to new sensors being inserted into the network, or even due to designers moving sensors around during a network re-design phase (for example, in response to a change in the requirements of the network. In this paper, we address the problem of covering a given path by a limited number of sensors — in our case to two, and show its relation to the well-studied matrix multiplication problem.
Chen, Peng (Inventor); Buric, Michael P. (Inventor); Swinehart, Philip R. (Inventor); Maklad, Mokhtar S. (Inventor)
A gas sensor includes an in-fiber resonant wavelength device provided in a fiber core at a first location. The fiber propagates a sensing light and a power light. A layer of a material is attached to the fiber at the first location. The material is able to absorb the gas at a temperature dependent gas absorption rate. The power light is used to heat the material and increases the gas absorption rate, thereby increasing sensor performance, especially at low temperatures. Further, a method is described of flash heating the gas sensor to absorb more of the gas, allowing the sensor to cool, thereby locking in the gas content of the sensor material, and taking the difference between the starting and ending resonant wavelengths as an indication of the concentration of the gas in the ambient atmosphere.
The SEAMONSTER Sensor Web: Lessons and Opportunities after One Year
Fatland, D. R.; Heavner, M. J.; Hood, E.; Connor, C.
The SouthEast Alaska MOnitoring Network for Science, Telecommunications, Education, and Research, or SEAMONSTER, is a NASA Earth Science Technology Office funded effort to deploy a sensor web in Southeast Alaska. One of the major benefits of this project is the potential for testbed applications for sensor web and sensor technologies is a harsh yet accessible environment. Another key aspect of SEAMONSTER is the project's illustration of the key differences between a sensor network and a sensor web. After the initial year of work on the project, we have instrumented the partially glaciated watershed of Lemon Creek, near Juneau, Alaska. The initial goal of this project is to develop a sensor web for monitoring the Lemon Glacier and its outlet stream, Lemon Creek. The sensor web is built upon a network of sensors with real time communication between nodes and semi-autonomous reconfigurability based on the information shared between nodes. The sensor web is designed to provide long term monitoring that is sensitive to local conditions to accurately record transient events with dynamic use of available resources (e.g. power, storage, communications bandwidth). Specifically, the sensor web described in this presentation allows us to develop our understanding of glacier hydrology and the influence of glacial runoff on the hydrology and hydrochemistry of Lemon Creek. We currently have 7 different stations monitoring 37 physical parameters. We are implementing communications via wireless 802.11b to transmit data from sensor web nodes back to the University of Alaska Southeast. The backbone of the sensor web is composed of Vexcel Microservers. These low-power servers are base stations with support for sub-networks, server support with respect to the rest of the network, and server behavior with respect to network-external contact. This presentation describes the methods we have used to build the SEAMONSTER sensor web, lessons learned after one year, future directions for the
Sensor Fish: an autonomous sensor package for characterizing complex flow fields and fish passage
Energy Technology Data Exchange (ETDEWEB)
Deng, Zhiqun; Martinez, Jayson J.; Lu, Jun
Fish passing through dams or other hydraulic structures may be injured or killed despite advances in turbine design, project operations, and other fish bypass systems. The Sensor Fish (SF) device is an autonomous sensor package that characterizes the physical conditions and stressors to which fish are exposed during passage through hydro facilities. It was designed to move passively as a neutrally buoyant object through severe hydraulic environments, while collecting high-resolution sensor data. Since its first generation1, the SF device has been successfully deployed in many fish passage studies and has evolved to be a major tool for characterizing fish passage conditions during fish passage in the Columbia River Basin. To better accelerate hydropower development, the U.S. Department of Energy Water Power Program provided funding to develop a new generation (Gen 2 SF) to incorporate more capabilities and accommodate a wider range of users over a broader range of turbine designs and operating environments. The Gen 2 SF (Figure 1) is approximately the size and density of a yearling salmon smolt and is nearly neutrally buoyant. It contains three-dimensional (3D) rotation sensors, 3D linear acceleration sensors, a pressure sensor, a temperature sensor, a 3D orientation sensor, a radiofrequency (RF) transmitter, and a recovery module2. A low-power microcontroller collects data from the sensors and stores up to 5 min of data on internal flash memory at a sampling frequency of 2048 Hz. The recovery module makes the SF positively buoyant after a pre-programmed period of time, causing it to float to the surface for recovery.
Simulation of a fast framing staring sensor
Energy Technology Data Exchange (ETDEWEB)
Jefferson, K.J.; Wickstrom, R.D.
A sensor system simulation has been developed which aids in the evaluation of a proposed fast framing staring sensor as it will perform in its operational environment. Beginning with a high resolution input image, a sequence of frames at the target sensor resolution are produced using the assumed platform motion and the contribution of various noise sources as input data. The resulting frame sequence can then be used to help define system requirements, to aid algorithm development, and to predict system performance. In order to assess the performance of a sensor system, the radiance measured by the system is modeled using a variety of scenarios. For performance prediction, the modeling effort is directed toward providing the ability to determine the minimum Noise Equivalent Target (NET) intensities for each band of the sensor system. The NET is calculated at the entrance pupil of the instrument in such a way that the results can be applied to a variety of point source targets and collection conditions. The intent is to facilitate further study within the user community as new mission areas and/or targets of interest develop that are not addressed explicitly during sensor conceptual design.
Gas Sensors Based on Electrodeposited Polymers
Directory of Open Access Journals (Sweden)
Boris Lakard
Full Text Available Electrochemically deposited polymers, also called "synthetic metals", have emerged as potential candidates for chemical sensing due to their interesting and tunable chemical, electrical, and structural properties. In particular, most of these polymers (including polypyrrole, polyaniline, polythiophene and their derivatives can be used as the sensitive layer of conductimetric gas sensors because of their conducting properties. An important advantage of polymer-based gas sensors is their efficiency at room temperature. This characteristic is interesting since most of the commercially-available sensors, usually based on metal oxides, work at high temperatures (300–400 °C. Consequently, polymer-based gas sensors are playing a growing role in the improvement of public health and environment control because they can lead to gas sensors operating with rapid detection, high sensitivity, small size, and specificity in atmospheric conditions. In this review, the recent advances in electrodeposited polymer-based gas sensors are summarized and discussed. It is shown that the sensing characteristics of electrodeposited polymers can be improved by chemical functionalization, nanostructuration, or mixing with other functional materials to form composites or hybrid materials.
Underwater sensor nodes and networks
National Research Council Canada - National Science Library
Lloret, Jaime
.... This special issue is focused on collecting recent advances on underwater sensors and underwater sensor networks in order to measure, monitor, surveillance of and control of underwater environments...
Ferreira, Mário F. S.; Castro-Camus, Enrique; Ottaway, David J.; López-Higuera, José Miguel; Feng, Xian; Jin, Wei; Jeong, Yoonchan; Picqué, Nathalie; Tong, Limin; Reinhard, Björn M.; Pellegrino, Paul M.; Méndez, Alexis; Diem, Max; Vollmer, Frank; Quan, Qimin
Sensors are devices or systems able to detect, measure and convert magnitudes from any domain to an electrical one. Using light as a probe for optical sensing is one of the most efficient approaches for this purpose. The history of optical sensing using some methods based on absorbance, emissive and florescence properties date back to the 16th century. The field of optical sensors evolved during the following centuries, but it did not achieve maturity until the demonstration of the first laser in 1960. The unique properties of laser light become particularly important in the case of laser-based sensors, whose operation is entirely based upon the direct detection of laser light itself, without relying on any additional mediating device. However, compared with freely propagating light beams, artificially engineered optical fields are in increasing demand for probing samples with very small sizes and/or weak light-matter interaction. Optical fiber sensors constitute a subarea of optical sensors in which fiber technologies are employed. Different types of specialty and photonic crystal fibers provide improved performance and novel sensing concepts. Actually, structurization with wavelength or subwavelength feature size appears as the most efficient way to enhance sensor sensitivity and its detection limit. This leads to the area of micro- and nano-engineered optical sensors. It is expected that the combination of better fabrication techniques and new physical effects may open new and fascinating opportunities in this area. This roadmap on optical sensors addresses different technologies and application areas of the field. Fourteen contributions authored by experts from both industry and academia provide insights into the current state-of-the-art and the challenges faced by researchers currently. Two sections of this paper provide an overview of laser-based and frequency comb-based sensors. Three sections address the area of optical fiber sensors, encompassing both
Ferreira, Mário F S; Castro-Camus, Enrique; Ottaway, David J; López-Higuera, José Miguel; Feng, Xian; Jin, Wei; Jeong, Yoonchan; Picqué, Nathalie; Tong, Limin; Reinhard, Björn M; Pellegrino, Paul M; Méndez, Alexis; Diem, Max; Vollmer, Frank; Quan, Qimin
Sensors are devices or systems able to detect, measure and convert magnitudes from any domain to an electrical one. Using light as a probe for optical sensing is one of the most efficient approaches for this purpose. The history of optical sensing using some methods based on absorbance, emissive and florescence properties date back to the 16th century. The field of optical sensors evolved during the following centuries, but it did not achieve maturity until the demonstration of the first laser in 1960. The unique properties of laser light become particularly important in the case of laser-based sensors, whose operation is entirely based upon the direct detection of laser light itself, without relying on any additional mediating device. However, compared with freely propagating light beams, artificially engineered optical fields are in increasing demand for probing samples with very small sizes and/or weak light-matter interaction. Optical fiber sensors constitute a subarea of optical sensors in which fiber technologies are employed. Different types of specialty and photonic crystal fibers provide improved performance and novel sensing concepts. Actually, structurization with wavelength or subwavelength feature size appears as the most efficient way to enhance sensor sensitivity and its detection limit. This leads to the area of micro- and nano-engineered optical sensors. It is expected that the combination of better fabrication techniques and new physical effects may open new and fascinating opportunities in this area. This roadmap on optical sensors addresses different technologies and application areas of the field. Fourteen contributions authored by experts from both industry and academia provide insights into the current state-of-the-art and the challenges faced by researchers currently. Two sections of this paper provide an overview of laser-based and frequency comb-based sensors. Three sections address the area of optical fiber sensors, encompassing both
A technique to measure eyelid pressure using piezoresistive sensors.
Shaw, Alyra J; Davis, Brett A; Collins, Michael J; Carney, Leo G
In this paper, novel procedures were developed using a thin (0.17 mm) tactile piezoresistive pressure sensor mounted on a rigid contact lens to measure upper eyelid pressure. A hydrostatic calibration system was constructed, and the influence of conditioning (prestressing), drift (continued increasing response with a static load), and temperature variations on the response of the sensor were examined. To optimally position the sensor-contact lens combination under the upper eyelid margin, an in vivo measurement apparatus was constructed. Calibration gave a linear relationship between raw sensor output and actual pressure units for loads between 1 and 10 mmHg ( R(2) = 0.96 ). Conditioning the sensor prior to use regulated the measurement response, and sensor output stabilized about 10 s after loading. While sensor output drifts slightly over several hours, it was not significant beyond the measurement time of 1 min used for eyelid pressure. The error associated with calibrating at room temperature but measuring at ocular surface temperature led to a very small overestimation of pressure. Eyelid pressure readings were observed when the upper eyelid was placed on the sensor, and removed during a recording. When the eyelid pressure was increased by pulling the lids tighter against the eye, the readings from the sensor significantly increased.
An SPR based sensor for allergens detection.
Ashley, J; Piekarska, M; Segers, C; Trinh, L; Rodgers, T; Willey, R; Tothill, I E
A simple, sensitive and label-free optical sensor method was developed for allergens analysis using α-casein as the biomarker for cow's milk detection, to be used directly in final rinse samples of cleaning in place systems (CIP) of food manufacturers. A Surface Plasmon Resonance (SPR) sensor chip consisting of four sensing arrays enabling the measurement of samples and control binding events simultaneously on the sensor surface was employed in this work. SPR offers several advantages in terms of label free detection, real time measurements and superior sensitivity when compared to ELISA based techniques. The gold sensor chip was used to immobilise α-casein-polyclonal antibody using EDC/NHS coupling procedure. The performance of the assay and the sensor was first optimised and characterised in pure buffer conditions giving a detection limit of 58ngmL(-1) as a direct binding assay. The assay sensitivity can be further improved by using sandwich assay format and amplified with nanoparticles. However, at this stage this is not required as the detection limit achieved exceeded the required allergens detection levels of 2µgmL(-1) for α-S1-casein. The sensor demonstrated good selectivity towards the α-casein as the target analyte and adequate recoveries from CIP final rinse wash samples. The sensor would be useful tool for monitoring allergen levels after cleaning procedures, providing additional data that may better inform upon wider food allergen risk management decision(s) that are made by food manufacturer. In particular, this sensor could potentially help validate or optimise cleaning practices for a given food manufacturing process. Copyright © 2016 Elsevier B.V. All rights reserved.
From sensor output to improved product quality
Hertog, M.L.A.T.M.; Vollebregt, Martijntje; Unzueta, I.; Hoofman, R.J.O.M.; Lammertyn, J.
The research conducted in the European PASTEUR project focussed on perishables monitoring through smart tracking of lifetime and quality. The aim was to develop a wireless sensor platform to monitor the environmental conditions of perishable goods in the supply chain between producer and
Optical arc sensor using energy harvesting power source
Energy Technology Data Exchange (ETDEWEB)
Choi, Kyoo Nam, E-mail: firstname.lastname@example.com; Rho, Hee Hyuk, E-mail: email@example.com [Dept. of Information and Telecommunication Engineering Incheon National University Incheon 22012 (Korea, Republic of)
Wireless sensors without external power supply gained considerable attention due to convenience both in installation and operation. Optical arc detecting sensor equipping with self sustaining power supply using energy harvesting method was investigated. Continuous energy harvesting method was attempted using thermoelectric generator to supply standby power in micro ampere scale and operating power in mA scale. Peltier module with heat-sink was used for high efficiency electricity generator. Optical arc detecting sensor with hybrid filter showed insensitivity to fluorescent and incandescent lamps under simulated distribution panel condition. Signal processing using integrating function showed selective arc discharge detection capability to different arc energy levels, with a resolution below 17 J energy difference, unaffected by bursting arc waveform. The sensor showed possibility for application to arc discharge detecting sensor in power distribution panel. Also experiment with proposed continuous energy harvesting method using thermoelectric power showed possibility as a self sustainable power source of remote sensor.
Optical arc sensor using energy harvesting power source
Choi, Kyoo Nam; Rho, Hee Hyuk
Wireless sensors without external power supply gained considerable attention due to convenience both in installation and operation. Optical arc detecting sensor equipping with self sustaining power supply using energy harvesting method was investigated. Continuous energy harvesting method was attempted using thermoelectric generator to supply standby power in micro ampere scale and operating power in mA scale. Peltier module with heat-sink was used for high efficiency electricity generator. Optical arc detecting sensor with hybrid filter showed insensitivity to fluorescent and incandescent lamps under simulated distribution panel condition. Signal processing using integrating function showed selective arc discharge detection capability to different arc energy levels, with a resolution below 17J energy difference, unaffected by bursting arc waveform. The sensor showed possibility for application to arc discharge detecting sensor in power distribution panel. Also experiment with proposed continuous energy harvesting method using thermoelectric power showed possibility as a self sustainable power source of remote sensor.
Integration Of Sensor Orientation Data Into An Augmented Reality Technology
Directory of Open Access Journals (Sweden)
Edgaras Artemčiukas
Full Text Available Currently, such microelectromechanical sensors as accelerometers, gyroscopes and magnetometers are the dominant sensors in mobile devices. The market of mobile devices is constantly expanding and focused on sensor integration process by adding supplementary functionality for the applications; therefore, it is possible to adapt these sensors for augmented reality technology solutions. Many augmented reality solutions are based on computer vision processing methods in order to identify and track markers or other objects. However, the main problem is chaotic environment, lighting conditions where object recognition and tracking in real-time becomes difficult and sometimes is an impossible process. This paper analyses possibilities to apply microelectromechanical sensors. Additionally, it investigates quaternion use for sensor data to estimate reliable and accurate camera orientation and represent virtual content in augmented reality technology.
Flexible wearable sensor nodes with solar energy harvesting.
Taiyang Wu; Arefin, Md Shamsul; Redoute, Jean-Michel; Yuce, Mehmet Rasit
Wearable sensor nodes have gained a lot of attention during the past few years as they can monitor and record people's physical parameters in real time. Wearable sensor nodes can promote healthy lifestyles and prevent the occurrence of potential illness or injuries. This paper presents a flexible wearable sensor system powered by an efficient solar energy harvesting technique. It can measure the subject's heartbeats using a photoplethysmography (PPG) sensor and perform activity monitoring using an accelerometer. The solar energy harvester adopts an output current based maximum power point tracking (MPPT) algorithm, which controls the solar panel to operate within its high output power range. The power consumption of the flexible sensor nodes has been investigated under different operation conditions. Experimental results demonstrate that wearable sensor nodes can work for more than 12 hours when they are powered by the solar energy harvester for 3 hours in the bright sunlight.
Directory of Open Access Journals (Sweden)
A. H. Nasr
Full Text Available Sensors usually must be calibrated as part of a measurement system. Calibration may include the procedure of correcting the transfer of the sensor, using the reference measurements, in such a way that a specific input-output relation can be guaranteed with a certain accuracy and under certain conditions. It is necessary to perform a calibration to relate the output signal precisely to the physical input signal (e.g., the output Digital Numbers (DNs to the absolute units of at-sensor spectral radiance. Generic calibration data associated with Egyptsat-1 sensor are not provided by the manufacturer. Therefore, this study was conducted to estimate Egyptsat-1 sensor specific calibration data and tabulates the necessary constants for its different multispectral bands. We focused our attention on the relative calibration between Egyptsat-1 and Spot-4 sensors for their great spectral similarity. The key idea is to use concurrent correlation of signals received at both sensors in the same day (i.e., sensors are observing the same phenomenon. Calibration formula constructed from Spot-4 sensor is used to derive the calibration coefficients for Egyptsat-1. A brief overview of the radiometric calibration coefficients retrieval procedures is presented. A reasonable estimate of the overall calibration coefficient is obtained. They have been used to calibrate reflectances of Egyptsat-1 sensor. Further updates to evaluate and improve the retrieved calibration data are being investigated.
Urgence et activité débordée dans le grand commerce Emergency and overflow activity in mass retailing Urgencia y actividad desbordada en el comercio masivo
Directory of Open Access Journals (Sweden)
Julien Choquet
Full Text Available Le grand commerce est un secteur d'activité où la performance économique se mesure à l'échelle des volumes de marchandise distribuée. Derrière cet indicateur se cachent des politiques de gestion des ressources humaines largement déterminées par les questions de productivité du travail. En effet, ces entreprises commerciales ont à résoudre une équation majeure consistant à placer la bonne quantité de personnel au bon endroit et au bon moment, du fait de la forte irrégularité des affluences de la clientèle dans leurs points de vente. L'usage du temps de travail acheté constitue donc une variable fondamentale dans la maîtrise des coûts de production. Les solutions choisies ne sont pas sans incidences sur les conditions temporelles d'exécution du travail des salariés dans les magasins. Leur activité oscille entre intensité et débordement, ce qui impacte fortement leur manière d'appréhender leurs tâches, leurs relations avec la clientèle et leur capacité à vivre sereinement leur travail.Mass retail is a sector where economic performance tends to be measured by the volume of goods distributed – an indicator built upon human resource management policies that are largely rooted in the productivity of labour. Commercial companies are constantly seeking to move large numbers of staff members to the right place at the right time, a complicated exercise given customers' irregular presence at points of sale. The way that companies use the working time that they have purchased therefore constitutes a key variable in controlling production costs. The solutions they choose will affect the temporal conditions determining employees' in-store execution of tasks. Such activities tend to fluctuate between intensity and overflow. In turn, this strongly affects how staff members apprehend tasks; relations with customers; and their sense of serenity at work.El comercio masivo es un sector de actividad cuyos resultados
Kalman Filter for Estimation of Sensor Acceleration Using Six - axis Inertial Sensor
Energy Technology Data Exchange (ETDEWEB)
Lee, Jung Keun [Hankyong National University, Anseong (Korea, Republic of)
Although an accelerometer is a sensor that measures acceleration, it cannot be used by itself to measure the acceleration when the orientation of the sensor changes. This paper introduces a Kalman filter for the estimation of a sensor acceleration based on a six-axis inertial sensor (i.e., a three-axis accelerometer and three-axis gyroscope). The novelty of the proposed Kalman filter lies in the fact that its state vector includes not only the tilt angle variable but also the sensor acceleration. Thus, the filter can explicitly estimate the latter with a high accuracy. The accuracy of acceleration estimates were validated experimentally under three different dynamic conditions, using an optical motion capture system. It could be concluded that the performance of the proposed Kalman filter was comparable to that of the state-of-the-art estimation algorithm employed by the Xsens MTw. The proposed algorithm may be more suitable than inertial/magnetic sensor-based algorithms for various applications adopting six-axis inertial sensors.
Advanced Magnetoimpedance Sensors
Li, Bodong
This thesis is concerned with the advanced topics of thin film magnetoimpedance (MI) sensors. The author proposes and develops novel MI sensors that target on the challenges arising from emerging applications such as flexible electronics, passive wireless sensing, etc. In the study of flexible MI sensor, the investigated sensors of NiFe/Cu/NiFe tri-layersare fabricated on three flexible substrates having different surface roughness: Kapton, standard and premiumphotopaper. Sensitivity versus substrate roughness analysis is carried out for the selection of optimal substrate material. The high magnetic sensing performance is achieved by using Kapton substrate. Stress simulation, incorporated with the theory of magnetostriction effect, reveals the material composition of Ni/Fe being as a key factor of the stress dependent MI effect for the flexible MI sensors. In the development of MI-SAW device for passive wireless magnetic field sensing, NiFe/Cu/NiFe tri-layersand interdigital transducers(IDT) are designed and fabricated on a single piece of LiNbO3substrate, providing a high degree of integration and the advantage of standard microfabrication. The double-electrodeIDT has been utilized and proven to have an optimal sensing performance in comparison to the bi-directional IDT design. The optimized high frequency performance of the thin film MI sensor results in a MI-SAW passive wireless magnetic sensor with high magnetic sensitivity comparing to the MI microwire approach. Benefiting from the high degree of integration of the MI thin film element, in the following study, two additional sensing elements are integrated to the SAW device to have a multifunctional passive wireless sensor with extended temperature and humidity sensing capabilities. Analytical models havebeen developed to eliminate the crossovers of different sensing signals through additional reference IDTs, resulting in a multifunctional passive wireless sensor with the capability of detecting all three
Droplet-Sizing Liquid Water Content Sensor Project
National Aeronautics and Space Administration — Icing is a significant aviation hazard, and icing conditions continue to be difficult to precisely forecast or locate in real time. An in-situ sensor, which can be...
Micro Coriolis mass flow sensor with integrated resistive pressure sensors
Groenesteijn, Jarno; Alveringh, Dennis; Schut, Thomas; Wiegerink, Remco J.; Sparreboom, Wouter; Lötters, Joost Conrad
We report on novel resistive pressure sensors, integrated on-chip at the inlet- and outlet-channels of a micro Coriolis mass flow sensor. The pressure sensors can be used to measure the pressure drop over the Coriolis sensor which can be used to compensate pressure-dependent behaviour that might
Resistive pressure sensors integrated with a Coriolis mass flow sensor
Alveringh, Dennis; Schut, Thomas; Wiegerink, Remco J.; Sparreboom, Wouter; Lötters, Joost Conrad
We report on a novel resistive pressure sensor that is completely integrated with a Coriolis mass flow sensor on one chip, without the need for extra fabrication steps or different materials. Two pressure sensors are placed in-line with the Coriolis sensor without requiring any changes to the fluid
Thermal Anemometry Grid Sensor
Directory of Open Access Journals (Sweden)
Martin Arlit
Full Text Available A novel thermal anemometry grid sensor was developed for the simultaneous measurement of cross-sectional temperature and axial velocity distribution in a fluid flow. The sensor consists of a set of platinum resistors arranged in a regular grid. Each platinum resistor allows the simultaneous measurement of fluid temperature via electrical resistance and flow velocity via constant voltage thermal anemometry. Cross-sectional measurement was enabled by applying a special multiplexing-excitation scheme. In this paper, we present the design and characterization of a prototypical sensor for measurements in a range of very low velocities.
Professional Android Sensor Programming
Milette, Greg
Learn to build human-interactive Android apps, starting with device sensors This book shows Android developers how to exploit the rich set of device sensors—locational, physical (temperature, pressure, light, acceleration, etc.), cameras, microphones, and speech recognition—in order to build fully human-interactive Android applications. Whether providing hands-free directions or checking your blood pressure, Professional Android Sensor Programming shows how to turn possibility into reality. The authors provide techniques that bridge the gap between accessing sensors and putting the
Thermal Anemometry Grid Sensor.
Arlit, Martin; Schleicher, Eckhard; Hampel, Uwe
A novel thermal anemometry grid sensor was developed for the simultaneous measurement of cross-sectional temperature and axial velocity distribution in a fluid flow. The sensor consists of a set of platinum resistors arranged in a regular grid. Each platinum resistor allows the simultaneous measurement of fluid temperature via electrical resistance and flow velocity via constant voltage thermal anemometry. Cross-sectional measurement was enabled by applying a special multiplexing-excitation scheme. In this paper, we present the design and characterization of a prototypical sensor for measurements in a range of very low velocities.
Characterization of Pixel Sensors
Oliveira, Felipe Ferraz
It was commissioned at CERN ATLAS pixel group a fluorescence setup for characterization of pixel sensors. The idea is to measure the energies of different targets to calibrate your sensor. It was measured four matrices (80, 95, 98 and 106) of the Investigator1 sensor with different deep PW using copper, iron and titanium as target materials. The matrix 80 has a higher gain (0.065 ± 0.002) and matrix 106 has a better energy resolution (0.05 ± 0.04). The noise of the setup is around 3.6 mV .
Shir, Daniel; Ballard, Zachary S.; Ozcan, Aydogan
Mechanical flexibility and the advent of scalable, low-cost, and high-throughput fabrication techniques have enabled numerous potential applications for plasmonic sensors. Sensitive and sophisticated biochemical measurements can now be performed through the use of flexible plasmonic sensors integrated into existing medical and industrial devices or sample collection units. More robust sensing schemes and practical techniques must be further investigated to fully realize the potentials of flexible plasmonics as a framework for designing low-cost, embedded and integrated sensors for medical, environmental, and industrial applications. PMID:27547023
Sensor Suits for Human Motion Detection
National Research Council Canada - National Science Library
Feng, Maria Q
... shape, the stiffness and the density. This sensor suit is made of soft and elastic fabrics embedded with arrays of MEMS sensors such as muscle stiffness sensor, ultrasonic sensors, accelerometers and optical fiber sensors, to measure...
Vision-based traffic data collection sensor for automotive applications.
Llorca, David F; Sánchez, Sergio; Ocaña, Manuel; Sotelo, Miguel A
This paper presents a complete vision sensor onboard a moving vehicle which collects the traffic data in its local area in daytime conditions. The sensor comprises a rear looking and a forward looking camera. Thus, a representative description of the traffic conditions in the local area of the host vehicle can be computed. The proposed sensor detects the number of vehicles (traffic load), their relative positions and their relative velocities in a four-stage process: lane detection, candidates selection, vehicles classification and tracking. Absolute velocities (average road speed) and global positioning are obtained after combining the outputs provided by the vision sensor with the data supplied by the CAN Bus and a GPS sensor. The presented experiments are promising in terms of detection performance and accuracy in order to be validated for applications in the context of the automotive industry.
Vision-Based Traffic Data Collection Sensor for Automotive Applications
Llorca, David F.; Sánchez, Sergio; Ocaña, Manuel; Sotelo, Miguel. A.
This paper presents a complete vision sensor onboard a moving vehicle which collects the traffic data in its local area in daytime conditions. The sensor comprises a rear looking and a forward looking camera. Thus, a representative description of the traffic conditions in the local area of the host vehicle can be computed. The proposed sensor detects the number of vehicles (traffic load), their relative positions and their relative velocities in a four-stage process: lane detection, candidates selection, vehicles classification and tracking. Absolute velocities (average road speed) and global positioning are obtained after combining the outputs provided by the vision sensor with the data supplied by the CAN Bus and a GPS sensor. The presented experiments are promising in terms of detection performance and accuracy in order to be validated for applications in the context of the automotive industry. PMID:22315572
Distributed Sensor Coordination for Advanced Energy Systems
Energy Technology Data Exchange (ETDEWEB)
Tumer, Kagan [Oregon State Univ., Corvallis, OR (United States)
towards "what to observe" rather than "how to observe" in large sensor networks, allowing the agents to actively determine both the structure of the network and the relevance of the information they are seeking to collect. In addition to providing an implicit coordination mechanism, this approach allows the system to be reconfigured in response to changing needs (e.g., sudden external events requiring new responses) or changing sensor network characteristics (e.g., sudden changes to plant condition). Outcome Summary: All milestones associated with this project have been completed. In particular, private sensor objective functions were developed which are aligned with the global objective function, sensor effectiveness has been improved by using "sensor teams," system efficiency has been improved by 30% using difference evaluation functions, we have demonstrated system reconfigurability for 20% changes in system conditions, we have demonstrated extreme scalability of our proposed algorithm, we have demonstrated that sensor networks can overcome disruptions of up to 20% in network conditions, and have demonstrated system reconfigurability to 20% changes in system conditions in hardware-based simulations. This final report summarizes how each of these milestones was achieved, and gives insight into future research possibilities past the work which has been completed. The following publications support these milestones [6, 8, 9, 10, 16, 18, 19].
Perimeter Coverage Scheduling in Wireless Sensor Networks Using Sensors with a Single Continuous Cover Range
Directory of Open Access Journals (Sweden)
Hung Ka-Shun
Full Text Available In target monitoring problem, it is generally assumed that the whole target object can be monitored by a single sensor if the target falls within its sensing range. Unfortunately, this assumption becomes invalid when the target object is very large that a sensor can only monitor part of it. In this paper, we study the perimeter coverage problem where the perimeter of a big object needs to be monitored, but each sensor can only cover a single continuous portion of the perimeter. We describe how to schedule the sensors so as to maximize the network lifetime in this problem. We formally prove that the perimeter coverage scheduling problem is NP-hard in general. However, polynomial time solution exists in some special cases. We further identify the sufficient conditions for a scheduling algorithm to be a 2-approximation solution to the general problem, and propose a simple distributed 2-approximation solution with a small message overhead.
Virtual Redundancy for Safety Assurance in the Presence of Sensor Failures Project
National Aeronautics and Space Administration — Both autopilot systems and human pilots, particularly human pilots operating in instrument meteorological conditions, rely heavily on sensor feedback to safely...
RESTful Web services in Wireless Sensor Networks
Moreno Yeste, Pol
Premi Accenture al millor projecte de fi de carrera d'Enginyeria de Telecomunicació en Serveis Telemàtics (curs 2011-2012) English: Wireless Sensor Networks (WSNs) have become very popular in recent years. A WSN consists of distributed autonomous sensors to monitor physical or environmental conditions and to cooperatively send their data through the network to a main location. A WSN facilitates the creation of low-cost networks that can be used for multiple applications when the use of wir...
Aluminum nanocantilevers for high sensitivity mass sensors
DEFF Research Database (Denmark)
Davis, Zachary James; Boisen, Anja
We have fabricated Al nanocantilevers using a simple, one mask contact UV lithography technique with lateral and vertical dimensions under 500 and 100 nm, respectively. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Furthermore, it is shown...... that Al has a potential higher sensitivity than Si based dynamic sensors. Initial testing of these devices has been conducted using a scanning electron microscope setup were the devices were tested under high vacuum conditions. The Q factor was measured to be approximately 200 and the mass sensitivity...
Magnetic Nanocomposite Cilia Tactile Sensor
Alfadhel, Ahmed
A multifunctional biomimetic nanocomposite tactile sensor is developed that can detect shear and vertical forces, feel texture, and measure flow with extremely low power consumption. The sensor\\'s high performance is maintained within a wide operating range that can be easily adjusted. The concept works on rigid and flexible substrates and the sensors can be used in air or water without any modifications.
Sensor employing internal reference electrode
DEFF Research Database (Denmark)
The present invention concerns a novel internal reference electrode as well as a novel sensing electrode for an improved internal reference oxygen sensor and the sensor employing same.......The present invention concerns a novel internal reference electrode as well as a novel sensing electrode for an improved internal reference oxygen sensor and the sensor employing same....
DEFF Research Database (Denmark)
Hussain, Dil Muhammad Akbar; Ahmed, Zaki; Khan, M. Z.
The use of multiple sensors typically requires the fusion of data from different type of sensors. The combined use of such a data has the potential to give an efficient, high quality and reliable estimation. Input data from different sensors allows the introduction of target attributes (target type......, size) into the association logic. This requires a more general association logic, in which both the physical position parameters and the target attributes can be used simultaneously. Although, the data fusion from a number of sensors could provide better and reliable estimation but abundance...... of information is to be handled. Therefore, more extensive computer resources are needed for such a system. The parallel processing technique could be an alternative for such a system. The main objective of this research is to provide a real time task allocation strategy for data processing using multiple...
Directory of Open Access Journals (Sweden)
Robert H. Morris
Full Text Available Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...
Water Properties Sensor Project
National Aeronautics and Space Administration — In this Phase II project, Kaitech proposes to develop and demonstrate a Water Properties Sensor (WPS) sensing system to synchronously measure the spectral inherent...
Graphene Chemical Sensor Project
National Aeronautics and Space Administration — The sensor uses graphene based devices to sense the surface potential of a graphene channel exposed to an analyte. When analyte molecules adsorb onto the...
Complex pendulum biomass sensor
Hoskinson, Reed L.; Kenney, Kevin L.; Perrenoud, Ben C.
A complex pendulum system biomass sensor having a plurality of pendulums. The plurality of pendulums allow the system to detect a biomass height and density. Each pendulum has an angular deflection sensor and a deflector at a unique height. The pendulums are passed through the biomass and readings from the angular deflection sensors are fed into a control system. The control system determines whether adjustment of machine settings is appropriate and either displays an output to the operator, or adjusts automatically adjusts the machine settings, such as the speed, at which the pendulums are passed through the biomass. In an alternate embodiment, an entanglement sensor is also passed through the biomass to determine the amount of biomass entanglement. This measure of entanglement is also fed into the control system.
Ebert, R.
The paper presents the status of laser sensors based on direct and coherent detection technology. Potential and limitations of 3D- laser radar, laser vibrometer, and gated viewing systems will be described.