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AD-A NOTES ON ATMOSPHERIC STABILITY TURBULENCE AND ITS I/i.. IEASUREMENTS(U) ARMY DUGWAY PROVING GROUND UT C A BILTOFT MAR 85 DPG-TR
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1 AD-A NOTES ON ATMOSPHERIC STABILITY TURBULENCE AND ITS I/i.. IEASUREMENTS(U) ARMY DUGWAY PROVING GROUND UT C A BILTOFT MAR 85 DPG-TR UNCLASSIFIED F/G 4/1i N
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3 AD TECOM No. 7-CO-RD4-DPO-007 Lf) DPG Document No. DPG-TR Zf) TECHNICAL REPORT NOTES ON ATMOSPHERIC STABILITY, TURBULENCE, AND ITS MEASUREMENT CHRISTOPHER A. BILTOFT leteorological Branch Test Design and Analysis Division Materiel Test Directorate US ARMY DUGWAY PROVING GROUND DTIC DUGWAY, UT O MARCH 1985 EL-CTE JUN APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED
4 Disposition Instructions Destroy this report when no longer needed. Do not return to the originator. Disclaimer Statement The views, opinions, and/or findings in this report are those of the author(s) and should not be construed as an official Department of the Army position,. unless so designated by other official documentation. Trade Names Statement The use of trade names in this report does not constitute an official indorsement or approval of the use of such commercial hardware or software. This report may not be cited for purposes of advertisement. 4i~ce5sion Fogr "' S GRAc U - DTIC TA[ Uu)annsunce Pd JustificatioL_._... BY / Distribution/ Availability Coda& Avail and/or D; Special1 ' * :::. -- :.. : - :. : _..:.. ::..:. :... -.:.. ::: :: ::: ::::: :..:..::: :.. : ; ; ): ::) :. : ". -,. : - ---"L -4. t ,-,b.,,a...,w,.,',m e,;,.,,...,,.,.,,,, -,_,, : - -:,.":,.
5 UNCLASS I FI ED SECURITY CLASSIFICATION OF THIS PAGE Wen Date Entered) REPORT DOCUMENTATION PAGE READ INSTRUCTIONS BEFORE COMPLETING FORM A 1. ' ' REPORT NUMOER 2. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUMBER TITLE (ind Subtitle) S. TYPE OF REPORT 6 PERIOD COVERED NOTES ON ATMOSPHERIC STABILITY, TURBULENCE, AND Technical Report ITS MEASURMENT 6. PERFORMING ORG. REPORT NUMBER DPG-TR AUTHOR(s) 8. CONTRACT nr GRANT NUMBER(&) Christopher A. Biltoft 9. PERFORMING DRGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, TASK AREA &*ORKUNITNUMeERS US Army Dugway Proving Ground ATTN: STEDP-MT-DA-M JL Dugway, UT CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE US Army Dugway Proving Ground March 1985 Dugway, UT NUMBER OF PAGES MONITORING AGENCY NAME & ADDRESS(Il different from Controlling Office) IS. SECURITY CLASS. (of this eport) ISa. UNCLASSIFIED DECLASSIFICATION/DOWNGRADING SCHEDULE 16 DISTF ibjtion STATEMENT (of this Report).---. O Approved for public release; distribution unlimited. % I7 DISTRIBU'ION STATEMENT (of the abstra ct entered In Block 20, If different from Report) S 18. SUPPLEMENTARY NOTES.0 19 KEY WOROS fcontinue on t.ere. ide II nc...ry ind Identlfy by block number) Richardson Number friction velocity stability Obukhov length roughness length Gaussian diffusion similarity K-theory turbulent kinetic energy turbulence meteorological instrumentation 20 ASTACT (Coaf&fn-" If nace-ey m-- ideify by block number) Modernization of Dugway's diffusion test capabilities include the procurement of state-of-the-art instrumentation and an upgrade in data collection methodology and modeling. Dispersion of a buoyant, passive plume is due.1 to transport by mean atmospheric motions. Although K-theory and Gaussian diffusion equations are burdened by restrictive assumptions, these equations offer the most practical means of modeling the effects of turbulence on diffusing material., M73 14 E.. IOO, o, o VoSISOSSOLETE UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PA)F (Ubtn [)&te Enteed)
6 'A UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE(Whn Data Entered) BLOCK 20. ABSTRACT (cont'd) Turbulence occurs as vortex stretching in a sheared environment causes an energy cascade towards progressively smaller eddy sizes until viscous dissipation occurs. Direct turbulence measurements require an assortment of instrumentation due to the range of eddy sizes. Consequently, it is most economical to estimate turbulence from stability parameters and most models accept such turbulence estimators as input. The Obukhov Length, a stability parameter obtained from principal turbulent kinetic energy components, can be obtained from tower profile data using flux-gradient relationships. LED scintillometers, acoustic sounders, radiometers, precision thermometers, and sonic anemometers are needed to upgrade Dugway's turbulence measurement capabilities. Data from these instruments will help define test go/ no-go conditions, improve quality control, enhance posttest analysis capabilities, and provide improved input for diffusion modeling. UNCLASSI FI ED SECURITY CLASSIFICATION OF THIS PAGE(When Dae Entered)
7 NOTES ON AT1OSPHERIC STABILITY, TURBULENCE, AND ITS MEASUREMENT TABLE OF CONTENTS PAGE ACKt:OWLEDGEM1ENTS... i IEXECUTIVE SUMMARY... i 1. INTRODUCTION A DEFINITION OF TURBULENCE THE LOGARITHMIC AND POWER LAW WIND PROFILES 9 4. K-THEORY AND GAUSSIAN DIFFUSION KINETIC ENERGY AND THE RICHARDSON NUMBERS THE OBUKHOV LENGTH AND z/l ;TABILITY, TURBULENCE, AND DIFFUSION NEASUREMENT REQUIREMENTS AND INSTRUMENTATION CONCLUSIONS APPErIDIX A. SYMBOLS... A-i APPLNDIX B. REFERENCES... B-1 APPENDIX C. ABBREVIATIONS... C-i APPE IDIX D. DISTRIBUTION LIST... D-1 0v
8 ACKNOWLEDGEMENTS I wish to express my appreciation for the thorough technical review of this document by Mr. John White of the Dugway Meteorology Branch and by Mr. James and Ms. Christina Wheeler of the Dugway Technical Editing Section. My thanks are also extended to Ms. Shauna Edgeman of the Word Processing Section for performing nontechnical editing and text revision. I L I B. '
9 EXECUTIVE SUMMARY This :')cument examines some basic relationships between atmospheric diffusion, tur)ulence, and stability. It lists the measurements required for an adequate decription of the atmosphere for diffusion applications and the types of eq.!ipment needed for obtaining these measurements. A substance released into the atmosphere is dispersed by atmospheric motions. Turbulent motions determine the rate of spread of the material. Mean motions transport the material downwind. Dispersion involves scales of motion ranging from the wavelengths of light (measured in micr3meters) to synoptic-scale motions (measured in many kilometers). Creation of turbulence begins when the incoming flux of solar radiation is absorbed by the earth's surface and part of it is reradiatek as heat. This causes thermal discontinuities near the ryound. These discontinuities and friction from the interaction of surface roughness elements and viscous forces in the atmosphere produce heat and momentum gradients. These gradients cause nonequilibrium conditions where energy is transported and dissipated through turbulent motions. Once created, turbulent eddies gradually break down into smaller eddies until they are so small that viscous dissipation into heat occurs. This process of turbulence creation and destruction continues until the driving energy is removed from the system. Adequate description of a passive substance diffusing into a turbulent atmosphere requires a wide variety of meteorological measurements and algorithms. The Navier-Stokes equations used to describe the turbulent atmosphere are not amenable to direct solutions. Certain simplifying assumptions allow limited solutions that can yield diffusion equations used to model the turbulent atmosphere. The sophistication and accuracy of the models vary with the amount of detailed turbulence measurements or calculations available and the degree of realism of the algorithms used. Several forms of information can he used in turbulence models. The most direct forn, is turbulence measurements. However, these may not be available because of time, cost, or logistic problems. Also, most models lack the sophistication required to handle detailed turbulence data. Turbulence can also be described as a function of stability, the best estimates of which are rati)s of heat and momentum fluxes derived from the principal components of the turbulent energy equation. Profile measurements of wind and temperature provide mean wind and temperature model input data and are used for calculation of gradients. If fluxes of heat and momentum are assumed to remain essentially constant within the surface boundary layer, flux/gradient relationships provide a direct means of calculating stability from profile measurements. The Obukhov Length is an excellent stability parameter for use in turbulence models. It is derived from the turbulent kinetic energy equation with a minimum of qualifyinq assumptions and can be reliably obtained from high quality wind and temperature profile measurements. An adequate description of atmospheric turbulence will require a variety - of meteorological instruments. Sets of pyranometers and pyrgeometers are needed for measurement of fluxes of long and shortwave radiation through a surface. Scintillometer measurements of refractive index structure near the ground will supply information on eddy activity in the viscous dissipation iii
10 range. Micrometeorological anemometer cups and vanes and )recision thermometers, at logarithmically-spaced height intervals from 2 to 16 meters, are the most reasonable source of profiles of mean wind and teiperature. Instruments capabl. of measuring high-frequency fluctuations could provide data for turbulence spectrum analysis. Correct combinations of these instruments could provide data on the fluxes of heat, momentum, and moisture. Acoustic sounders can provide in-depth measurements of wind, estimates of bulk turbulence, and infortation )n the depth of convection or mixing layers. Scintillometers can provide the )ossibility of calculating path-averaged wind and divergence. An expanded, iml.roved mesonet grid and thorough modernization of the weather station would provide the rteso- and synoptic-scale information needed to describe the setting in which turbulence events occur. p The information will be most useful if the instruments are deployed and the data collected, analyzed, and entered into the model by people with a firm understanding of the assumptions used and knowledge of the limitations of the site and conditions of data collection. When the data are collected at sites approximate'y homogeneous in space and with meteorological conditions stationary in time, turbulence can be described as a function of stability. Significant departures from these conditions vastly complicate data interpretation. Stability parameters can be used as test go/no-go criteria, for test data quality con.rol, and for modeling. If data from the instruments discussed above were ivailable, in-depth posttest analysis would be possible. I I iv
11 1. INTRODUCTION: Diffusion meteorologists agree that behavior of a plume released into the atmosphere is controlled by meteorological influences. Unless the release is accompanied by the emission of a tremendous &mount of heat, initial source characteristics are quickly overwhelmed and plume behavior becomes a function of the motions in the atmosphere into which the plume is released. The mean wind field transports the released material downrange and turbulent motions cause horizontal and vertical spreading of the material. Transport is a function of mean wind fields that are readily measured. Diffusion is a function of turbulent eddies that are much more ;ubtle and difficult to quantify. A basic equation describing concentraticn (x, mg/mn) of an inert, nondepositing material, diffusing at distance x (meters) downwind from a continuous ground level gaseous point source, over a surface homogeneous in space, into an atmosphere stationary in time is x QI(w cku), (1.1) where Q is the source strength in mg/sec, ay and a z7 are the crosswind and vertical plume standard deviations and u is the transport wind speed. The ayazu in Equation 1.1 is proportional t the volume occupied by the diffusing material, assumino normal or Gaussian distribution. Derivation of this result is performed in Section 4 of this document. The double overbar on transport wind speed indicates that it is a mean wind speed averaged over travel time and depth of the cloud. Equation 1.1 quickly becomes complicated as different source confiqur^ations or chemical reactions occur, or as atmospheric characteristics change. Pasquill (1976) discusses a the horizontal component of cloud growth, as a function of downwind trave, ristare and measured standard deviation of the horizontal wind angle (OA), as expresse! by equation 1.2. Gy = X t(x) (1.2) Equation 1.2 applies to a stationary wind field free of horizontal and vertical wind shears. These conditions can be approximated within the first several tens of meters above ground level and over travel times of several tens of minutes. The function f(x) assumes a value of unity near the source and decreases as a function of travel distance and meteorological variables. The ja in Equation 1.2 is the horizontal wind angle standard deviation, a bulk turbulence parameter obtained from turbulence measurements. It should represent the integral of horizontal turbulent fluctuations over the entire spectrum of eddy sizes for a given time. In oractice, the measurement is limited on the low frequency (large eddy) side by sampling duration and is.....,
12 limited on the high frequency (small eddy) side by instruient response characteristics an,! data sampling rate. Other factors affectinq the magnitude of q A are adequacy of instrument response characteristics and instrument exposure. Algorith:is comparable to Equation 1.2 are available for describing oz, the vertical measure of cloud growth, as a function of x. The most useful of these algorithms include the description of az as a function of the vertical component of turbulence, represented as the vertical wind angle standard deviation, 0 e. The scales of motion that consist of eddies somewhat smaller than the diffusing cloud contribute most significantly to diffusion through the qa and ae terms. Scales of motion larger than the cloud tend to move the cloud as a whole. Turbulent eddy activity near the earth's surface is the sum of a dynamic or mechanical component generated by wind blowing over roughness elements (e.g., trees) and a convective component caused by buoyancy. The neutral or adiabatic atmosphere contains only the mechanical turbulence component where eddy activity depends on the interaction of wind with surface roughness. Diabatic atmospheres also include buoyant low-frequency eddies, in the unstable case, and an assortment of high-frequency eddies superimposed on intermittent low-frequency waves in the stable case. Algorithms pertaining to the neutrdl through unstable diabatic atmosphere near the surface will be primarily addressed because these are the conditions under which most current testing is done at US Army Dugway Proving Ground (DPG), Utah. Just as liffusion calculations require specification of the turbulence field, turbulence can either be measured or estimated from a similarity theory. Surface layer similarity theory is a collection of dimensional and physical arguments that permit description of turbulence as functions of a stability parameter. Stability parameters are combinations of pertinent variables used to describe the degree of departure from the adiabatic condition. The usefulness of stability parameters is a function of the accuracy with which they can be calculated and how well they represent actual conditions. This document describes some elementary relationships between atmospheric diffusion, turbulence, and stability parameters derived from similarity arguments. The purpose is to examine these relationships, determine the measurements required for an adequate description of the atmosphere for diffusion applications, and suggest the types of equipment that can be used to obtain these measurements. 2. A DEFIIITION OF TURBULENCE: The coordinate system shown in Figure 2.1 is used in the following discussion: The x axis is positive to the right, the y axis is positive towards the top of the page, and the z direction is a perpendicular directed out of the page. Components of the wind (u, v, and w) are defined along the x, y, and z axes, respectively. The mean wind flow is assumed to be to the right along the x axis. Vector quantities are indicated with an arrow overbar (-). 2
13 The stress tensor or shear stress (t) is defined as a force per unit area applied in normal or tangential components to a surface. Figure 2.1 shows a voiume with stress tensors applied to an xy plane (constant z surface). For a viscous fluid, there are nine stress components, three on each plane. Tensors tzy and TZX operate in the xy plane, while TZZ is normal (90 ) to the xy plane. The first stress tensor subscript indicates the face on which the stress acts and the second subscript indicates the direction of stress action. With inviscid or frictionless fluids, the tangential stress components are zero. Then the normal stress tensor, acting in tension, is opposed by pressure forces only. By convention, tension is designated as positive and pressure (Pzz) as negative. For a Newtonian viscous fluid, which the atmosphere approximates, momentum transfer caused by an applied tangential stress is proportional to the rate of strain (or momentum gradient). For a Newtonian viscous fluid moving horizontally above a stationary boundary, the stress (TZXO, Tzyo) is proportional to the rate of strain (au/az or av/az) as expressed in Equation 2.1. Zz TZZ -PZZ T.zz TZX Y Figure 2.1. Coordinate System. TZX 0 = U/_ I Tzy = V/aZ (2.1) where w is a constant of proport'onality known as the coefficient of viscosity. The subscript o on rzxo and 7zy o denotes the fact that these tangential viscous terms arise because of the mctionj of a viscous fluid above a stationary surface. In the atmosphere, viscous terms are small except near a surface where the velocity gradient is large or at the high frequency end of the turbulence spectrum. The x component of viscous force per unit mass on a volume of air is then represented as in Equation 2.2. Fx = (i/p) ;zxo/z = (L/p).] 2 u/;z 2. (2.2) 3
14 The stress terms described above are used in Navier-Stokes equations which express Newton's Second Law for motion in a Newtonian viscous fluid. For the u component of an incompressible viscous fluid, the instantaneous equation of motion is du/dt = (-1/p)aP/x + fc + (11/P)[; 2 u/ax u/ay u/az 2 ]. (2.3) Equation 2.3 iresents acceleration of the u component of the wind as the resultant of pressure gradient force, Coriolis force, and viscous forces. All forces in Equation 2.3 are per unit mass. The full vector form of the equation of motion is used in Section 5 for deriving the turbulent kinetic energy equation. Normally, the rate of change in vertical wind speed gradients greatly exceeds horizontal accelerations, that is 2u/;z 2 >> 2 u/;x 2, 3 2 u/3y 2 (2.4) and these smaller terms in Equation 2.3 can be neglected. Similar equations can be written for the v and w wind components. In addition to the equation of motion, a statement of continuity is required to describe the action of turbulence. The equation of continuity is most easily visualized by examination of flow tnrough a unit volume (Figure 2.2). z PuAyAZ Az [pu + (a(pu)/ax) 6x] AyAz!Yx AX Figur, low Through a Unit Volume. In Figure 2.2 -onsider mass inflow (pu) multiplied by unit area AyAz and mass outtlow as p + (V(ou)/ x)ax where ( (pu)/x)ax expresses changes that take place while le fluid passes through the volume. Then, the net rate of mass inflow per un t volure equals the local rite of change of density, as given in the three-dimensional mass divergence equation (continuity equation), - P/t= 2(pu)/x + ;(pv)/;y + (pw)/az V-pV. (2.5) 4
15 Equation 2.13, neglecting the total d,,rivative and viscous terms, then becrmes (i/p) %/ Dx - f= (i/)[ Dt-Kr Zax) /x + (-K<j Y-P < rt l/3z)/ 3z] (4.9) and solutions are possible with the assumpt ion that Km is some known function along each axis. Similar expressions for heat can be written with the \<-theory rel ttionship - ' K h /a,(4.10) vhere 3 represents potential temperatore. In the early years of diffusion work, the magnitude o' K for each application was generally unknown. Because of this, the "Reynoids Analogy" was frequently employed. This analogy assumed equivalence of the diffusivities for,nentiim, heat, and suspended i-aterial, i.e K 0 = Kh = K material (4.11) Several orobl,,nis with this anal ocy are: a. orentum transfer occjs as the result of pressure forces which do not o. rat(,equivalently on fields of heat or suspended material.,ir A matcial released into the air at a ternperature different than the te-nieratur,' will underqo displacements relati,,e to ambient eddy motions. c. Any diffusing material motions ccused by heating, evaporation, radiation ab.orptirnn, or differential motions caused hy inertial or aerodynamic efects (;ettli,,] of droplets, sailing of spores, etc.) will affect diffusivity. d. Difftisivity gradients may also be caused 1y terrain or roughness ele- i mits.hicn ( ause shears, vortex sireddinq. or wake flows. It is, thnref )re, qenerally iccepted that- K. -K h v c,<iateria' (4.12) ,,-i. i m - : m a lm,m'~ i, mi12
16 K is called a coefficient of eddy diffusivity. The concept of K arises from an assumption that the mixing of eddies in the atmo-phere is analogous to molecular mixing. 'lixing on the molecular scale occurs is molecules travel over a characteristic molecular length scale defined as, mean path distance (Z) before colliding with other molecules. Rradshaw (1971) points out several problems witn the analogy: a. Turbulent eddies are continuous and contiguous, whereas gas molecules are discrete and collide only at intervals. b. Although molecular free Paths are small compared to the dimension of the flow, turbulent eddies are nol. In spite of these deficiencies, the mixing length analogy and the resultant ed'y diffusivity or K-theory relationships remain popular because they provide the simplest solutions to diffusion problems. Alternative numerical methods dre beyond the means and requirements of most operational diffusion programs. :Jnfort~iately, all the complexities of turbulent interactions influence the magnitide of K. Adequate specification of K is difficult because it is a complex fu-,ction of height above the surface and stability. It also varies with the cliaracteristics of the diffusing substance to be treated. The most familiar forms of K are those for momentum and heat. This is because wind and temperature are the most frequently measured atmospheric variables. The turbulent transfer coefficient for momentum (K m ) is defined as the product of a characteristic eddy velocity and a characteristic eddy length scale, e.g. Km E R'W') Z (4.7) Similar turbulent transfer coefficients or eddy diffusivities can readily be defined for sensible heat (Kh.), moisture (KI), or fractional atmospheric components (K material). I An example of K-theory utility is the "first order closure" or eddy diffusivity (K) closure solutions to the Navier-Stokes equations (Equation 2.13), where eddy stress is expressed directly in terms of gradients obtained from the mean motion field. Neglecting the viscous terms (a/p 2 az ) and assuming that the total change with respect to time (du/dt) is zero, Equation 2.13 is reduced to a balance between the pressure gradient forces, the Coriolis term, and Reynolds stresses. K-theory relates Reynolds stresses to mean gradients using an analogy to viscous stresses in a Newtonian fluid. Equation 4.8, for example, relates G'V' to the vertical gradient of wind. V4 1~iT~ K ua (4.8) 17 I 2
17 The existtnce of sou-ces or sinks which cause variabil Ity in Q has been difficult to (uantify. Variations in Q may be due to deposition, physical, or chemical changes. A diffusion model must account for thesp changes to satisfy continuity, anij a number of schemes are available to do this. For some trials a "budget" is obtained by passing a diffusing cloud through a vertical sampling array, which collects a series of point samples to be used to back calculate Q. Such sampling procedures tend to be elaborate and involve considerable expense. Also, cloud growth rates constrain this procedure to use near the source. i,nother approach is to take advantage of modern tracer technology. Modern tracers are inert, nontoxic gases that have low background concentrations arid are readily measured to low concentrations. When released in a known ratio with other substances, these tracers can be used to evaluate the presence of sources or sinks for the substance being tested. Remote sensing techniques such as lidar scanning may also help resolve source strength measurement problems. Assuming nondivergence of the mean component, as in Equation 4.3, the total derivative of Rwith the nonzero mean components fror1 Equation 4.2 becomes -dx'dt = -[a/at + W- 1-x( I + v T y + = a 'a')fx + ('')/y + N( ' X)l3z (4.4) At this point, K-theory or gradient transfer theory is used to obtain an operational solution for some models. The alternatives are cumbersome numerical techniques that require extensive computer time and have not derionstrated practical utility ir, solving diffusion problems. With K-theory, it is assumed that the flux of a :;ubstance across a fixed surface can be expressed in terms of the mean gradients of that sujbstance normal to the surface, with a diffusivity term acting as a constant of proportionality. For example, the first term on the riqht in Equation 4.4, (u'') can be expressed by T "x / x, (4.5) Where Kx is the diffusivity coefficient along the x-axis. Analogous expressions are readily found for the other components. Replacing the eddy flux terms with gradient transfer forms, the right side of Equation 4.4 becomes dx/dt = 3(Kx rx/ax)/ax + O(Ky T-- y)/ y + 3(K z F-Iaz)/az (4.6) 16
18 accumulated dose, etc. The remainder of this section will discuss only x in its relation to diffusion equations, because sampling techniques are beyond the scope of this document. Consider a fractional component or "pollutant" emanating from a point or line source in the atmosphere. At the source, the concentration approaches infinity (Xo + -) and at infinite distance from the source, the concentration approaches zero (x. + 0). At intermediate distances, the gradients 3x/ax, 3x/3y, and 3X/3z are finite in the x, y, and z directions. Within these limits, a statement of continuity for an incompressible fluid analogous to Equation 2.5 pertains, -3x/at = 3(ux)/ax + D(vx)/ay + 3(wx)/Z = V.xV = V.Vx + XV-V. (4.2) The X in Equation 4.2 is composed of a mean (j) component representative of the average concentration in the volume of interest, and a deviation (X') due to eddies carrying different concentrations as they move through a measured volume. The product of the fluctuating (u', v', w') component with x' represents a flux through the volume. As before, average values of fluctuating components are zero, but correlated products of fluctuating components are nonzero. At this point the first set in a series of assumptions are made: a. The assumption of nondivergence is applied to the mean concentration component. X(3ulIx + a-way + 37wlaz) = iv.v = 0. (4.3) b. Density is assumed to be constant. Variations in X are then essentially caused by varying amounts of the fractional component, not by changes in air density. c. It is assumed that there are no additional sources or sinks for the fractional component, i.e., Q remains constant. Measurements should be made in every diffusion test to check the degree of conformity of actual conditions with these assumptions. Divergence computations from path-averaged wind measurements could verify the first assumption. If possible, the divergence computation should be made on length and time scales similar to the scale of the diffusion test. Although the magnitude of divergence does not directly enter the diffusion equations used to model trial results, the presence of significant divergence could explain some of the deviations of the actual measurements from expected results. Density is easily monitored as a function of temperature and pressure.. Density variations at a specific site during a test series are usually inconsequential. However, density differences must be considered when test results from different sites or under significantly different meteorological conditions are compared. 15
19 U2/Ul = (Z2/Z 1 )m (3.14) where m is some fractional exponent. Exponent m assumes a value near 0.14 for the neutral case, but varies with stability, site roughness, and height of measurement above the surface. Exponent m is difficult to specify accurately because its magnitude is influenced by many different factors. This is unfortunate because small variations in m cause large changes in u 2 /u 1. In spite of these limitations, power law formulations are popular because they provide the simplest solutions to diffusion equation wind profiles. An accurate specification of m for diffusion tests requires continuous, representative readings of wind profiles through the depth of a diffusing cloud. Remote wind sounding techniques are wzll suited to provide these data within the lower troposphere. 4. K-THEORY AND GAUSSIAN DIFFUSION: With a basic definition of turbulence and two approaches to SBL wind profiles at hand, it is now appropriate to examine some basic diffusion relationships. This is not a critical examination of diffusion models, for which many references exist. This is a discussion of some of the assumptions used, but frequently not noted, in the process of developing models or designing diffusion test programs. Suggestions are also made concerning measurements necessary to verify assumptions and conduct satisfactory diffusion tests. The quantity of airborne material is frequently aescribed or measured as a fractional component of the air in units of parts per million or similar units easily converted to a mixing ratio (R). For example, the National Institute of Occupational Safety and Health/Occupational Safety and Health Act (NIOSH/OSHA) Pocket Guide to Chemical Hazards (Mackison and Stricoff, 1980) describes permissible exposure limits for pollutants in this form. However, diffusion equations require introduction of fractional components in terms of a concentration (x) with units of (milli)grams per cubic meter, or related units. The conversion from R to x is achieved by multiplying the number of (milli)grams of fractional component per gram of air by air density [in (milli)grams per cubic meter], x Rp. (4.1) R is usually measured by instruments which must sample over finite time intervals. When sampling duration must be considered, the units of measure become a time-averaged concentration or a dosage (dd) with units of (milli)- gram-minutes per cubic meter. Also, a measure of the total accumulation of a fractional component over a period of time per unit area is often desirable. The lungs, for example, act as collecting devices, accumulating inhaled components over time. Many deposition or impaction type samplers operate in this fashion, but with varying efficiencies, yielding a measure of total accumulated dose (D) with units of (milli)grams. Total dose samplers are usually fairly simple collection devices, but their efficiencies are complicated by factors such as wind speed, angle of exposure to the wind, particle size, 14
20 The diabati:- influence function accounts for nonlinearities in the logarithmic wind profile, caused by thermal stratification. For neutral conditions *m = 1.0 and i = 0.0. Table 3.1 gives sample values of om and i as functions of the stability parameter z/l (defined in Section 6). Table 3.1. Dimensionless Shear (Im) and the Diabatic Influence Function (f) as Functions of the Stability Parameter z/l for the Unstable Case. z/l 'm i I The boundaries of the SBL, where stress remains nearly constant and the logarithmic law applies, can be defined. The lower boundary is z o, the top of the viscous sublayer where viscous shear becomes dominant at the expense of turbulent shear stress. Garratt (1980) finds that viscous effects distort the wind profile for heights in the range 1<z/zo<100 and suggests a method to compensate for this effect. The upper boundary is the top of the SBL. The top of the SBL is somewhat arbitrarily defined as the height at which T departs from T o by more than 20 percent. For a representative u, of 50 cm sec -1 and density held constant at g cm - 3, T o has a value of 3.0 g cm- 1 sec 2. Using Equation 2.13 and ignoring the viscous term, nonaccelerating components are in balance when (-1/p)3P/ax and fc are equal and of opposite sign. Then, accelerations (du/dt) are due to spatial changes in Reynolds stress terms. If changes in the horizontal stress components are neglected (as assumed earlier), accelerations are balanced by changes in stress with height. A typical wind speed change of 1.0 m sec -1 in 10 minutes produces a du/dt of cm sec -2. At this rate, stress remains within 20 percent of T o for 30 meters. It can be generally assumed that constant stress and the logarithmic wind profile are useful at DPG in the layer ranging from a few centimeters to a few tens of meters above the ground.in some cases the logarithmic wind profile may be representative up to 100 meters above ground level, well beyond the top of the SBL. The logarithmic wind profile and attendant similarity assumptions can therefore apply in the layer of interest for the majority of diffusion testing at DPG. The logarithmic wind profile (Equation 3.12) should be contrasted with the empirical power law wind profile, 13
21 Because of the influence of roughness lengtli on the wind profile, test sites for turulence mtasure'wents must be carefully chosen. Variations in roughness witn wind fetch greatly complicate interpretation of turbulence measurements. Also, introduction of man-made obstacles should be kept to a minimum at turbulence measurement sites. For sites with irees, large bushes, or similar impediments to flow, a correction factor, displacement height (d), must be introduced. Displacement height is a function of the height and the spacing of the flow impediments. Like zo, d is a characteristic of flow at a specific site, and may suffer from aerodynamic effects similar to z o in strong winds. The least complicated test sites for turbulence measurements contain no obstacles to cause a requirement for d. At DPG, bushes are widely spaced and generally less thar, half a meter tall. Therefore, d is considered inconsequential because of the general absence of large or densely packed obstacles to the flow. The full form of the logarithmic wind profile equation for an adiatatic atmosphere is given by Equation 3.10, with u(z) representing a mean wind at height z (valid for z>(d+zo)). U(z) = (u*/k) ln((z-d-zo)/z:) (3.10) At well chosen test sites, z o and d are small enough to be neglected in the numerator ot Equation To this point, the effects of stability on the wind profile have not been discussed. For near-neutral conditions, a plot of wind speed versus height is nearly a straight line on a log-linear plot, as in Figure 3.1. However, the wind profiles show significant departures from linearity for diabatic conditions. During unstable conditions, the wind profile is expected to increase more slowly than in the neutral case and, in stable conditions, the wind profile increases more rapidly than in the neutral case (Figure 3.1). To account for departures from linearity, a new variable, %m, the dimensionless wind shear, is introduced to Equation 3.9 so that 2z 3I u*ml/kz, (3.11) and a diabatic influence function (*) derived as a function of lm by Paulson (1970) is introduced to the logarithmic wind profile, as shown in Equation U(z) (u*/k) ln((z/zo)-*) (3.12) Equation 3.13 presents the functional relationship of 4) to 4m. = 2 ln((i + 4 ),2) +ln((1+ 42)/2) -2tan- 1 ', + 1T/2 (3.13) *- 12
22 (U 2 -U 1 )/u. = ln(z 2 /z l )/k, (3.8) where k is an empirical constant known as von Karman's constant. Wind profile studies showing a linear relationship between u and in z under adiabatic conditions tend to confirm the validity of Equation 3.8. The derivative of Equation 3.8 over an infinitesimal height yields the basis of a fundamental flux-gradient relationship, given in Equation 3.9. 'u/az = u,/kz (3.9) If z 1 in Equation 3.8 is chosen sufficiently close to the ground, u 1 is at the top of the viscous sublayer and is free of Reynolds stress momentum transfers from above. This sublayer height is determined by the dynamic roughness of the underlying surface. The dynamic roughness height (zo), according to Monin and Obukhov (1954), defines the characteristic scale of the underlying surface's micro nonuniformities. The magnitude of z o is determined by the properties of the underlying surface alone and should be independent of wind speed. In practice, z o changes somewhat as a function of wind speed because as wind speed increases, plants or other roughness eloments may assume more aerodynamically efficient shapes to reduce drag. Determination of z o for a given site is done experimentally, with careful measurements near the surface by using fast response instruments, such as hot wire anemometers. For very flat surfaces, z o can be less than one centimeter. Conversely, z o can approach 1 meter in built-up urban areas. For near neutral wind profiles, z o may be obtained at the intersection of the linear wind profile at u = 0 on a plot of u versus in z (Figure 3.1). Estimates of zo are obtained from the averages of repeated measurements using this procedure. Rough estimates of z o can also be obtained from the general characteristics of the site, as demonstrated by Hogstrom and Hogstrom (1978). Analysis of wind fields at DPG yield z o values ranging from 2 to 4 cm. unstable neutral / stable ln(z) 10.0 / S0. 1 U Figure 3.1. Wind Speed Versus Height (logarithmic scale). 11
23 The SBL, extending from a few centimeters to several tens of meters above the surface, is of great interest in turbulence and diffusion studies because this is the layer in which most h-iman activities occur. 2 Witqin the SBL the ratio T/p is nearly constant. This ratio has units of m sec -, the square root of which yields units of velocity. Consequently, the square root of T/p is defined as the friction velocity (u,). In the SBL, -u u2. (3.3) Friction velocity is the characteristic velocity within the SBL. It accounts for the effects of large scale pressure gradients and surface roughness effects on SBL winds (see Tennekes, 1982). Friction velocity is used to form dimensionless ratios with other SBL winds. The nondimensional SBL winds can then be conveniently described as a function of height, surface roughness, and stability. Monin and Obukhov (1954) used similarity between laboratory flow and flow within the SBL to obtain a logarithmic form of the wind profile. Within the SBL, the mean wind speed difference at two heights is related to the ratio of the heights as expressed in Equation 3.4, (U2-u )/u, = f (z 2 /z 1 ) (3.4) where f represents a function. To find the nature of f, three wind speed and height combinations were chosen such that Z3>Z2>zl and u3>u2>ul. Because S3- u = (U3- U2) + (u2- U1) (3.5) and Z3/Z1 = (z3/z2)'(z2/z1), (3.6) the functional form that satisfies Equations 3.5 and 3.6 is the logarithmic equality presented in generalized form using Equation 3.7. ln(&3/& 2 ) ln(e2/el) = ln(&3/e1) : lne3 - InE, : (ln& 3 - ln&2) + (In 2 - lnl) (3.7) Therefore, the required functional relationship between tne nondimensionalized wind of Equation 3.4 and the height ratio is,
24 .- - -" ". " ". ' Y.. ".. ' - L.,.'. "-. - r r ;.J, ;.., L. F. Richardson is said to have stated it as follows: Great whorls have little whorls That feed on their velocity... And the little whorls have lesser whorls, And so on to viscosity. 3. THE LOGARITHMIC AND POWER LAW WIND PROFILES: Two empirical equation forms, the logarithmic and power law profiles, describe the change in wind speed with height. The logarithmic profile originated with laboratory fluid flow measurements and has become part of the system of equations used for similarity theory descriptions of the turbulent atmosphere. Power law profiles came from attempts to fit vertical wind speed measurements with a simple exponential equation. The simpler power law forms are more mathematically tractable for use with diffusion equations than are logarithmic profiles. To overcome the impasse presented by intractable Navier-Stokes equations, fluid dynamicists used laboratory experiments for engineering solutions to fluid dynamics problems. A number of very useful semi-empirical relationships were developed from these experiments. One is the Reynolds Number (RE), a dimensionless ratio of accelerations to viscous stress gradients. When RE is large, flow is considered to be fully turbulent regardless of the scale of the experiment. With a large RE, the principle of dynamic similitude can be used to relate laboratory findings to turbulent processes in the atmosphere. Dynamic similitude considerations led to the application of logarithmic fluid velocity profiles observed in the laboratory to wind flow in the friction layer near the ground. Several unique flow layers have been found in laboratory flow simulations. In pipe flow, there is a thin layer (the viscous sublayer) close to the wall where the influence of viscosity is great and the viscous shear stress (u au/3z) is much larger than the Reynolds shear stresses. The viscous sublayer is often called the laminar sublayer due to absence of Reynolds stress. Stress at the wall (T O ) is given by Equation 3.1, where U is now defined as a mean wind along the direction of flow. T = 3 'U/3z (3.1) Outside the viscous sublayer in pipe flow, stress remains constant at its wall value (T-TO), but Reynolds stresses are predominant and viscous effects are small. Soviet scientists Monin and Obukhov (1954) noted the similarity of this pipe flow phenomenon to observed flows in the atmosphere. They defined the atmospheric constant stress layer, also known as the surface boundary layer (SBL), as a layer several tens of meters in depth in which T-T o = -PU 'W' constant. (3.2) * 9 *.... * *.-.
25 When winds are divided into mean (u) and fluctuating (ii) components, the cssumption is made that the sampling tine is sufficiently Lhort so variations in the mean motion are negligible, and sufficiently long soi that the average value of u' approaches zero. In other words, a "spectral!ap" is assumed to exist between the mean and turbulent components of flow. 'n practice, this condition can be approached over uniform terrain in the at'ospheric surface layer with sampling times of 10 to 60 minutes, assuming thait the wind field is not perturbed by transient mesoscale features. Under the,tssunption that a spectral gap exists, the flow is statistically stationary, i.e., turbulence statistics of the flow do not change with time and may be atdequately represented by time averages obtained from equipment mounted at fixed locations past which the fluid travels. To illustrate energy transfer from mean to turbulent flow, consider an average size eddy subjected to finite positive aw/az in a fluctuating wind field containing eddies larger and smaller than the eddy in question. If eddy volune remains constant, stretching of the eddy -n the z direction by the motions of larger eddies will be accompanied by contraction along the horizontal axis. Conservation of angular momentum requires the product of vorticity and radius to remain constant in the absence of v,scous dissipation. For example, conservation of angular momentum is the cause of the increase in spin. of an ice skater who brings his/her arms in close to his/her body. Consequently, the response of an eddy to aw/az stretching is an increase in the horizontal component of eddy vorticity as the horizontal dimensions of the eddy decrease. Vertical stretching therefore causes an anomaly in the horizontal wind field. As the larger eddies stretch the sample eddy, smaller eddies are being stretched by the sample eddy, dilutir.g its vorticity. The length scale of eddies decreases with stretching and mixinfl at each stage, establishing a cascade of energy to smaller eddy sizes. As energy progressively cascades to smaller length scales, there is an increasing tendency for equipartition of eddy energy along each axis. The condition of local homogeneity is achieved at the scale where the eddy statistical properties depend only on spatial separations and time differences. Isotropy occurs as the eddy properties become independent of axes orientation. The eddy size at which isotropy occurs is limited by height above the ground. The probability that larger eddy sizes will exhibit isotropy increases with height above the surface. For measurements at a given height, the largest eddy size for which isotropy occurs represents the beginning of the inertial subrange. The spectrum of eddy sizes in the inertial subrange is a function of the rate of turbulent energy dissipation per unit mass (E). At progressively smaller eddy sizes, the inertial subrange merges into the viscous subrange, where the eddy size spectrum is a function of w/p and F. At the lower end of the viscous subrance, eddy energy is converted to the kinetic energy of molecular motion (heat). Thus the nonlinear Reynolds stress terms of the Navier-Stokes equations extract energy from the mean flow and cascade it down the spectrum of eddy sizes. The viscous term acts as a sink at the lower end of the spectrum. Following the above arguments, Bradshaw (1971) defines turbulence as a three-dimensional time-dependent motion in which vortex stretching causes velocity fluctuations to spread to all wavelengths between a minimum determined by viscous forces and a maximum determined by the boundary conditions of the flow. *
26 V A more useful form of Equation 2.10 is obtained by assuming nondivergence for the fluctuating components, 3x + ay + a'/az = o, (2.11) I Multiplying Equation 2.11 by T', and recognizing that a(p T!, + a('p T')/7 + (W' '")/3z = Ti' J'/ c + Ui a'/ay + ' '83z + "I" U' Iax + ' /' 3y + ' T'I az, (2.12) the variance and covariance terms on the left side of Equation 2.12 can be substituted into the fluctuating part of Equation This produces the mean equation of motion in an atmosphere containing mean and fluctuating components as shown in Equation du/dt = (-/p) ap/ax + fc + (IP/P) u/az + (l/p) a(-3')/ax + (l/p) 3(-P 'V')/y + (lip) (2.13) I The mean terms in Equation 2.13 are similar to those in Equation 2.3, with the major difference being the addition of mean fluctuating component products. The additional terms formed from the variances and covariances of fluctuating wind components are known as Reynolds stresses. In the atmosphere, Reynolds stresses are larger than the viscous terms of the Navier-Stokes equations except very near the surface. The vertical terms containing -p' i' are of greatest interest because the rate of change in stress in the x and y directions is usually assumed to be small [i.e., a(' ')/ax, D(U'')/By approach zero]. Shear stress is defined in Equation 2.14 for the W'w' covariance term. Tzx = -'' Fm (2.14) The T'i' of Equation 2.14 must be represented by ((uw)+ (v'w2)) in the atmoshere. Equation 2.14 describes the mean transport of u' per unit time through a horizontal plane, which is a the vertical component of momentum flux (Fm) due to Reynolds stress. Comparison of Equations 2.1 and 2.14 shows that a gradient imposed on a flow containing mea- and fluctuating components will cause a momentum flux to develop. Flux-gradient relationships are developed further in Section 6. 7 "I
27 In Figure 2.3.a, au/ax + av/ay is negative, and 3w/Dz mu-it be equal and of opposite sign if the total velocity vector remains nondivergent. This condition, where the horizontai component (Vn.V) is negative, is known as convergence. Figure 2.3.b denionstrates the opposite effect for divergence (Vh'V positive and aw/az negative). In addition to convergence/divergence, a flid cross can display rotation about the origin, or vorticity (Figure 2.4). -. V-- Figure Vortici ty ax - au/ y). The divergenc_ and vorticity concepts introduced above are used with the equations of m.otion to describe the action of turbulence. First, however, additional stress terms caused by atmospheric eddy motio,s must be introduced. ~Consider an instantaneous wind field Mu divided into it- mean () and fluctu- 4.- ~ating Wu) components such that the time average of individual fluctuating components is zero (u' = 0), but the products u'u, u'v, etc. can be nonzero. Then, the x component of mass inflow, or momentum flux, through area AyAz in " FigurE 2.2 is UPU u &y z) =u pay Az =p(_ + u')ayz AZ P(-U + 2"Uu' +U'2 ty Z (2.9) 0l The mixed products (such as G') average to zero, but the average of products of the fluctuating terms (W;V, etc.) are nonzero so long as there is some degree of correlation between the fluctuating components. These nonzero products must be considered in the equations of mear motion. To show the contribution of fluctuating variance and covariance terms to the mean Navier-Stokes equations, divide the total derivative du/dt (from Equation 2.3) into its local (3u/at) and advective (V.Vu) components and expand it into mean (U) and average fluctuating components. The nonzero -) products are du/dtecmo3tf a + l ou/r x + though (210) {'....of th. fluctuatin terms-.i, tc.) are nonzero" so long. as there. is some=-,...: ;..,- + U' u'l + V' au' I y, + W' u (az The"" mixed prodcts (such s" aeraqe'to " " " ero, but te average"f "."- product


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A high school teacher and a finance manager will square off Nov. 6 for the George Washington District seat on the Stafford County Board of Supervisors.
Tom Coen, a Colonial Forge High School government teacher who was appointed to the seat earlier this year, says his local government experience—including a stint on the Planning Commission—makes him the most qualified candidate. His opponent, Gordon Silver, a finance manager for Cox Automotive, says he would fight to bring more tax dollars to southern Stafford, which he thinks has been shortchanged over the years.
Coen unsuccessfully vied for the seat as a Republican in 2003 and 2007, but is running as an independent this year. Supervisors voted unanimously in February to appoint him over Silver and five other candidates after Bob Thomas voluntarily stepped down from the seat to become a state delegate.
Silver, a Stafford native, received the Republican nomination, which he said reflects his fiscally conservative views and belief in the free-enterprise system.
Both candidates have emphasized their desire to minimize housing developments in their more rural district, which includes the site of George Washington's boyhood home. Coen said he helped create a program in which the county buys development rights from landowners, saying the measure has preserved nearly 500 acres of land. Some residents, he said, went on to buy additional farmland after the county purchased easements on their undeveloped property.
"My opponent hasn't even spoken at board meetings in favor of any of these things," said Coen, who has served on a variety of county and schools committees.
Silver acknowledged that the Purchase of Developments Rights program has saved farmland, but said applications can take years to process. The county, he said, should explore more efficient public–private partnerships, perhaps with the numerous land-preservation trusts throughout the state.
He said he could not yet say exactly how such a partnership would work.
"The need for preserving green space is not just something for quality of life, it's something that will help us be stronger financially in the future," he said, adding that housing developments do not pay for themselves.
Silver called Stafford's new restrictions on higher-density "cluster subdivisions" a step in the right direction because they limit those developments to parts of the county with access to public water and sewer. But he said the county opened itself up to lawsuits by not grandfathering in applications that had already been submitted.
A Stafford developer sued over the restrictions, and a circuit judge recently ruled that he could move forward with three applications for cluster subdivisions ahead of a January trial.
Coen, who supported the new limits on cluster subdivisions, questioned his opponent's commitment to managing growth, citing the Fredericksburg Area Construction Trust's $1,000 donation to Silver. Coen said he met with the organization but was never offered money.
He did not explicitly say whether he would have accepted a donation from the group, but explained: "I'm very leery of taking money from anybody that there may be strings attached. There may not be strings attached, but in life, perception is reality."
Silver, who said he is not pro-growth, said the construction trust purchased $1,000 worth of tickets to his "Community Cookout" fundraiser last month so that families could attend. The event included ice cream, hay rides and live music.
Silver criticized Coen for voting in favor of a capital plan this year that includes money for renovating, rather than rebuilding, Ferry Farm Elementary School. The county's capital plan includes $10.6 million to renovate Ferry Farm Elementary by fall 2020, but Silver thinks a rebuild would be more cost effective.
"We have to have someone who will draw a line in the sand and fight for our end of the county," he said. "I believe [Coen] folded like a cheap lawn chair."
Coen said he had two options: Vote to renovate Ferry Farm soon or wait at least another decade to rebuild the 61-year-old school.
He said he would love to rebuild Ferry Farm in the near future, but that the votes were not there to do so.
"The choice facing everybody was, kick the can down the road and hope you would get a rebuild in a decade or try something now," he said.
Neither candidate closed the door on increasing the real estate tax rate in the future.
Coen voted this year to maintain the tax rate of 99 cents per $100 of assessed value, which was technically a tax increase because of this year's rise in home values.
Stafford's budget this year included a 2.5 percent raise for teachers and local government employees—including deputies and firefighters—12 additional firefighters, five more deputies, and armed "school protection officers" in three of the county's 17 elementary schools.
"I was very proud that we put a lot of emphasis on trying to retain employees—police, fire, rescue and education," Coen said.
Silver said he's knocked on 2,500 doors and heard from just one resident who categorically opposed a tax increase. Most people would be OK with a minimal tax increase if it meant, say, retaining more teachers, he said.
"I hate to coin this term, but it would almost be political suicide to say, no new taxes and pound your hand, because the community really is not saying that," he said.
"They're not looking for pie-in-the-sky type things but … they do not mind paying for a decent teacher's salary, for decent fire and rescue, for infrastructure."
Coen described himself as a lifelong Republican and fiscal conservative, but said he ran as an independent because partisanship and special interests have no place in local office. He was endorsed by the Stafford Democratic Committee, but he said he has support from people of varying political beliefs.
"I just have a reputation for reaching across to anybody to get things done and look for a way to find common ground," he said.
Silver accused Coen of trying to have it both ways, adding: "You cannot be independent of a political party and accept a party endorsement."
Politics aside, Silver said he can relate to the rural lifestyle of the George Washington District's longtime residents.
The assistant chief for the Patawomeck Indians, Silver still lives on a family farm where he cut corn by hand as a child. The county has changed a lot since his childhood, but "we still have a vestige of that community—the farmers, the watermen—in [our] end of the county."
"And I understand them, I understand their way of life," he said.
Coen said that, being a teacher, he can relate to people on fixed incomes, something that plays into his decisions.
He's lived and taught in the county for 20 years and said some of his former students now own businesses here.
"I understand the pressures of people who are trying to make ends meet," he said "I understand the pressures of people trying to live in Stafford because housing prices and rent prices are so high."


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Kitchen & Bath Design News is the industry's leading business, design and product resource for the kitchen and bath trade.
Issue link: https://kitchenbathdesign.epubxp.com/i/1050194
Successful designers already have their favorite contractors, plumbers, carpenters, cabinet and tile installers on speed dial. But what about a favorite home technology consultant? If the answer is 'what' or 'who,' you might want to start re-thinking your team. In a just-published Kitchen Technology Report put out by the National Kitchen & Bath Association, more than half of surveyed consumers rated kitchen technology "important because it makes my life easier." UNMET NEEDS Consumers want to use their mobile devices and voice control to research recipes in the kitchen and simplify meal preparation, but are con- cerned about cyber security, cost, obsolescence and making their space look "techy," the report concludes. Designers are doing their best to stay ahead of the learning curve. They want to know more about smart appliances, centralized light- ing controls, device charging and storage, voice activation, whole-house controls and entertain- ment offerings, according to the research. The idea for the report "came from the NKBA 2018 Design Trends data, specifically the tech section, which asked: 'What do you have in your kitchen?' and 'What do you have in your bathroom?' When you compare what is out there in the market today and what our industry professionals – mostly our designers – say their clients have in their kitchen, it was apparent the gap was huge," declares Tricia Zach, market research analyst for the National Kitchen & Bath Association. "We knew that manufacturers are really into the kitchen tech, producing all these gadgets and putting lots of resource dollars into developing these products, but why aren't people putting it in their homes?" she questioned. "We wanted to understand what the barriers were." NKBA went to its Thirty Under 30 class of millennial industry leaders and asked what topic interested them the most. "Overwhelmingly, it came back technology. You can't sell what you don't under- stand," Zach points out. TECH TOURS CEDIA, an association for the home tech- nology industry, and NKBA want to make understanding easier for non-technology professionals. At CEDIA's annual expo this past September, two groups of architects, interior designers and kitchen and bath designers toured the San Diego Convention Center show floor with home technology consultants. The goal was to "forge a strong bond between the two industries," reports Brian Pagel, senior v.p. with Emerald Expositions. "These design professionals and integrators are early adopters of this important conversation." (Integrator is another term for home technology consultant.) "The show brought the designers and the integrators together. The Design Connection tours – where an experienced integrator led designers around the show floor – provided the perfect opportunity for designers to under- stand the nuances of kitchen tech. There were lots of questions asked and answered. The show was a great opportunity for integrators to connect with designers and vice versa," Zach observes. This was the first year CEDIA organized these tours, though they've been deepening their relationship with the design and construction in- dustry through their CEDIA pavilions at Design & Construction Week. There will be one (on the International Builder Show side) in 2019, as well. Those CEDIA design tour conversations were in depth. Joe Whitaker, CEDIA board member and president of The Thoughtful Home in Clayton, MO was one of the technol- ogy professionals leading a tour. "I was really impressed by the technical questions from the attendees. I was fielding questions on network security, centralized equipment and even speak- er placement," Whitaker recalls. "This group really wanted to know about technology and how it affects the home in more than just de- sign and architecture," he adds. Cyber security CEDIA Spotlights Home Technology Trends BY JAMIE GOLD, CKD, CAPS The recent CEDIA Expo boast- ed offerings to help designers looking to balance their clients' desire for smart appliances and new home technology against concerns related to security, cost, obsolescence and style. Technology is increasingly a part of kitchen planning and design. Voice control for advanced home automation is a major technology trend. Smart mirrors are a strong and growing bathroom trend. Photo: Courtesy of the National Kitchen & Bath Association; Photo by: Steven Steinhauser Photog- raphy; Kitchen design by Leslie Norton, LEED AP; Lighting: Leviton. Photo: Courtesy of Josh.AI Photo: Courtesy of Séura. 30 Kitchen & Bath Design News • November 2018 TREND SPOTTING


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Make Visio open and read hand drawn flowcharts(Picture from whiteboard) and convert them to corresponding shape objects in Visio
Flowcharts and processes are many times finalized as a group on big sheets of paper or whiteboards. A photo of this whiteboard or paper charts are then taken and emailed to user for creating the entire chart in Visio. Recommended Idea is to make visio read the photo file and translate the images into shapes best corresponding to the library. (Image recognition based idea)
1 vote
Abel Philip shared this idea


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Also, your food should not be in the freezer to long there is a limit on how long the items are to be in the freezer. After a while the water molecules will find their way out of the frozen food.
If the temperature is above 0 degrees F your food will get freezer burn because the temperature is to warm. When water molecules escape from your food oxygen molecules can change the color and the flavor of your food. Food that has freezer burn is safe to eat but some of it tastes strange and stale. Aluminum foil is very useful to mankind for wrapping something, keeping something warm, and for keeping things cold.
Aluminum foil is mad by repeated thinning of a large block of aluminum. Then they begin melting the aluminum in gas furnace which takes hours. After is has been melted they run it through a moveable machine to mix it around. The next step is the aluminum is crushed by hot rollers until it is 2 inches in width, then they use a knife to remove a thin piece which is small enough to make aluminum foil.
Aluminum foil is also used for construction, air conditioners, radios televisions, decorative products and many other things. Aluminum foil is inexpensive, its chemical proof, provides electric, and also uses less waste than many other materials.
Aluminum is used in very large amounts, and today there are seven major producers of aluminum in the United States. Plastic is used for many different things and can be shaped and formed into almost anything. Plastic is one of the most useful man-made products that were ever created.
Showed first characters. They were used in all commercial communications satellites, in most earth orbiters, and in some space probes. They are generally a prismatic resembling, or being a prism design, and packaged very efficiently. This means that the batteries can be stored on the spacecraft in a very compact form, eliminating the need for extraneous space Showed next characters.
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Some commentators have suggested that so-called? Chelsea Tractors' should be taxed much higher than other vehicles.
SCIENCE FAIR PROJECT TOPICS 1. From Gene to Genetics: What Kinds of Mutations Matter? 2. Don't Get burned! Measure the UV Index at different times of the day.
The goal of this human behavior science fair project is to investigate whether exciting packaging can convince children to eat healthier foods. Credits Michelle Maranowski, PhD, Science Buddies This project is based on the following California State Science Fair project: Beecher, A. ().
Essay about Science Fair that surprised us was the fact that a laundry detergent booster could make crystals. Significance Crystals are used for many reasons, one of them being scientist use them analyze the formats of compounds. How to write a science fair project research paper. Includes key areas for research and sample papers.
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Separate names with a comma.
Discussion in 'Random Ramblings' started by debilorrah, Mar 12, 2009.
Now I want pics
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Quote:Yeah you better hide....
She is conspicuous by her absense.....
WHAT/ WHERE WHERE? I KNEW I souuldn't have dawdled at the market!!!!
Are you sure shes back Debi? I dont see her.


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Another reason to love Dr. Seuss. When we visited the Dr. Seuss Museum a few weeks ago, there was lots of evidence that Dr. Seuss knew what was important in life. Here's another example. Let's all be someone who cares so that things get better.
Another reason to love Dr. Seuss. When we visited the Dr. Seuss Museum a few weeks ago, there was lots of evidence that Dr. Seuss knew what was important in life. Here's another example. Let's all be someone who cares so that things get better.
Posted in Link, Post, Quote | Tagged end plastic pollution, less plastic, plasticless, reduce plastic | Leave a Comment »
We visited the Dr. Seuss Museum in Springfield, Mass. a few weeks ago. I knew I liked Dr. Seuss. Since at least 1958, he knew what is important:
Posted in Post, Quote | Tagged freedom, health, kindness, relationships | Leave a Comment »
I found another great company on the right track with recyclable products that do not add to our plastics problem: Black Hog Brewing Co.
And the beer is original and great. I loved the Ginga' Ninga, a pale ale brewed with fresh ginger. Even the can is beautiful!
And, in addition to the great beer, they use recycled and recyclable plastic six pack rings.
Love it! You should too. Check out their various craft brews, locations, and store availability at their website: https://blackhogbrewing.com.
Posted in Link, Post, product | Tagged #lessplastic #Plasticless #NoMorePlastic, #lessplastic #Plasticless #NoMorePlastic #EarthDay2018, end plastic pollution, less plastic, lifestyle choice, plasticless, recycling, reduce plastic | Leave a Comment »
In life, especially in some careers and homes, so much of what we must handle can be conflict-ridden, time-sensitive and serious. Add to that our political environment of hatred and our regular news cycle of death and destruction. Is it any wonder that so many of us suffer from depression and anxiety?
One way to combat anxiety and feelings of depression is to increase the levels of serotonin in the brain. Serotonin is a neurotransmitter, a kind of chemical messenger that helps the brain function. More specifically, serotonin is a "feel good" neurotransmitter and a mood stabilizer that boosts feelings of wellness and balance. When serotonin levels are optimal, you are able to think more clearly, act rather than react, and address stressful situations with calm and clarity. If you have low serotonin levels, you may suffer from anxiety, sleeplessness, depression, agitation or lack of focus.
There's medication called SSRIs that increase levels of serotonin in the bram, and many of us take it. I took an SSRI for four years. Now that my circumstances are very different than when I started that medication, I wanted to try life without it. Note that I was always functioning and never had thoughts of harming myself, so this was a reasonable pursuit for me. If you are taking SSRIs or any other medication for anxiety or depression, do not stop your medication without discussing it with your doctor. Medication can be necessary for some people and some circumstances.
I stopped by SSRI about a two months ago. The journey has not been easy. Fortunately, there are ways to naturally increase the serotonin levels in the brain to reduce the negative effects of low serotonin levels. By focusing on these, my life without an SSRI is working. Here are five ways to naturally increase serotonin levels.
1. A Healthy Diet
A healthy, balanced diet is important for optimal serotonin levels. In particular, fish, eggs, nuts and seeds, pineapples and complex carbohydrates (like fresh fruits and vegetables and whole grains) increase serotonin levels. It is also important to limit added sugars because sugar disrupts normal chemical reactions in the brain, which can inhibit serotonin processing and production. Supplement your healthy diet with B vitamins, fish oil, holy basil, rodiola and L-tyrosine, all of which help the brain produce more serotonin.
2. Exercise and Body Work
Exercise is medicine — not just for your body, but for your brain. The most effective way to increase serotonin levels is with exercise. There are no side effects, and it always works. As little as 30 minutes of brisk walking three times each week will help.
In addition, body work methods including massage, acupuncture, acupressure and reflexology relieve stress and boost serotonin levels.
3. Grabbing Sunlight
Many people suffer from seasonal affective disorder (SAD) in the winter months when there is much less sunlight. This is because the brain has less serotonin when there is less sunlight. Spend at least 15 minutes each day in the sun. Go for a walk before work or after lunch, or sit by a sunny window on the commuter train. You can also purchase a light box for your office or home.
4. Using Your Mind
Thinking about past happy experiences, or looking at photos of those experiences, can boost serotonin levels. The same is true for keeping a gratitude journal and daydreaming about happy times. Spending time with loved ones and doing talk therapy with a trusted therapist are also great ways to get out of your own head and allow serotonin in. And a regular meditation practice (as little as five minutes a day) gives the brain space to relax and produce serotonin.
5. Taking Two for Well-Being
Ideally, you'll work the above tips into your daily and weekly life to increase and sustain your serotonin levels. But as a gift to yourself, try to take one day each month for a mental health day. As my friend Vanessa Price advised in "A Matter of Time," take two days if you can. Use the first day to catch up on stuff. Don't let your colleagues or clients
know you are working so that you have time to handle existing tasks without new tasks being added. Then use the second day as a true day off to boost your serotonin levels by finding some peace and mental clarity.
Posted in Link, Post | Tagged anxiety, depression, Exercise, food, friends, health, Nutrition, play, serotonin | Leave a Comment »
I was listening on Audible to The World According to Mr. Rogers. If you haven't been learning more about him in light of the recent documentary, now is a good time to do so. One of my favorite things he shared in his book was this thought:
He was discussing how it can be difficult when we see so many terrible things happening in our world. We see it and hear it everywhere. TV, radio, email, social media, real conversations. We learn about all the terrible things that people can do. Mr. Rogers' advice, which was given to him by his mother, is TO LOOK FOR THE HELPERS. Every terrible thing is followed by someone rising up to help. Focus on the HELPERS. Focus on what they do to help. Decide to be a HELPER yourself.
Thank you, Mr. Rogers. That is excellent advice.
Posted in Post | Tagged #begreat, book, compassion, empathy, giving, gratitude, health, kindness, lifestyle choice, shifting perspective, stress reduction, wisdom | Leave a Comment »
A version of this post first appeared here at Attorney at Work.
We know that free-play is important to the development of children. But it's also really important in the life of an adult. You may think that you don't need to play, that you don't have time to play, but there are good reasons to incorporate play into your life in order to be successful in life and in work.
What is play?
Brené Brown, researcher and author of Daring Greatly, describes play as anything that makes us lose track of time and self-consciousness. In other words, something that you experience as fun! Researcher Stuart Brown, MD (who is not related to Brené Brown), describes play as time spent without purpose. Unfortunately, I agree with Brené Brown, when she responds to this idea with "this sounds like the definition of an anxiety attack. I feel behind if I'm not using every last moment to be productive, whether that means working, cleaning the house or taking my son to baseball practice." Agreed. I mean, I barely have time to do all the purposeful things I need to do. Why would I waste time doing something that has no purpose!? Because play is important.
- The importance of play.
Play itself – meaning the activity in which you are engaging – need not have a purpose in the sense that it is not directly related to your productivity, not related to getting things done, and not related to achieving your financial or career goals. But it does have a purpose: creating the space in your mind where ideas can be born, perspective can improve, and the self is nurtured. In other words, play refreshes your mind and body, increases energy and prevents burnout, triggers creativity and innovation, and helps you see problems in new ways. But that's not all.
- Play is directly related to your success.
Research shows that "playing" relieves stress by triggering the release of endorphins, the body's natural feel-good chemicals. As we know, success at work is highly dependent upon the quality of your work, not just the quantity. And the quality of work is dependent upon your well-being. So, ultimately, play is vitally important to your success, in life and in work.
- Wanna come out and play?
Play is different for everyone. It should be something that you enjoy such that you lose track of time. It could be an organized sport, like basketball or tennis. Maybe it's brain-games like chess, crossword puzzles, or Sudoku. It could be a creative endeavor like painting, drawing, or scrapbooking; or performing arts such as an improv or dance class. Or maybe it's something that gets you moving but is more meditative, such as snorkeling, yoga, or hiking. The possibilities are endless.
- Incorporate playfulness into your work.
Your work is serious, but that doesn't mean that you need to be serious all the time, even in the office. When you hit a "glitch" in a matter or project, take some time out to "play" to reset your mind and come back with a fresh perspective on problem-solving. A small basketball hoop could help, or an air-hockey table in an extra conference room. Ask a colleague to join you, as playing with colleagues encourages teamwork and builds comradery.
- But what if it's been so long since you played that you can't remember what you like to do for fun?
Never fear. Even if you haven't engaged in an activity simply for the fun of it in a really long time, most likely there was a time in your past when you played. Think back to that time – maybe it was when you were a kid – and make a list of all the things you enjoyed back then. Which still sound appealing to you? Coloring? There are lots of great adult coloring books available. Playing pretend? Maybe try an acting class, or go see a play. Playing with your family pet? Perhaps volunteer at a local animal shelter. Photography? Pull that camera out and get out in the world and take some photos. Playing board games? Organize a monthly game night with friends. LEGOs? There are some seriously awesome LEGO sets available. Get creative. Try something you liked in the past, or try something new.
In the words of George Bernard Shaw, "We don't stop playing because we grow old; we grow old because we stop playing." When was the last time you played? No matter how long ago, make today the next time you play!
Posted in Post | Tagged curiosity, Exercise, freedom, health, Link, meditation, play, Quote, relationships, yoga | Leave a Comment »
Earlier this week, I posted about how meditation sucks … initially. In other words, the process of meditating is really not enjoyable in the beginning, but it gets better when you stick with it, and even if it never feels good, you still reap the benefits of doing it anyway.
Running is like that too. For me, at least the first half mile, and sometimes the first FULL mile, are really not enjoyable. I think all kinds of terrible thoughts, usually something like: running is dumb, why do I run, why am I doing this, I hate running, Patrick [my running coach] is crazy, etc. But, just like meditation, I keep doing it. And eventually, it starts to feel good. My mind relaxes and my body gets into a rhythm. Sometimes, the entire run feels bad. I can barely put one foot in front of the other. But, just like meditation, even when I "fail" at running, I reap the benefits by simply finishing the run, no matter the time it took or how it felt.
As Patrick would say, you can't be a runner if you won't agree to be uncomfortable sometimes. I think that's true of life too: you can't really live life if you can't be uncomfortable sometimes.
If you haven't tried running, give it a try. If you're not in a place physically to run, start with walking. Find a buddy. Find a coach. Join a group. It could change your life for the better! xo
Posted in Post | Tagged Exercise, health, running, Weight Loss | Leave a Comment »


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Coordinates: 53°41'07?N 2°36'06?W? / ?53.685336, -2.601602
Wheelton is a small village and civil parish of the Borough of Chorley, in Lancashire, England. According to the United Kingdom Census 2001 it has a population of 1,001.
Work for us - We are looking for enterprising, community-minded people with time and a digital camera to help populate our local websites.
We are currently working on the Wheelton profile and would be pleased to receive contributions from anyone who knows it well.
Online Hotel Reservations


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Exploring the: Software Zone
226 Results for: ProductSort by:
Software Release Enhances Reverse Engineering, Improves Mold Maintenance and Eases Conformal Cooling
The latest release of VISI software includes an extended direct interface to multiple portable measuring arms and scanning devices, ejector pin labeling functionality and advanced sketching of conformal cooling channels.
Advances to CAD/CAM Software Designed to Boost Productivity
Improvements to Vero Software's Alphacam are designed to improve productivity and save users time.
ROI Calculator Increases Savings and Reduces Tool Variety
The ROI Calculator from TDM Systems is an online tool that helps users calculate potential savings and their return on investment for tools when using TDM tool-management solutions.
Manager Aids Automation with Software and Machine Monitoring
NOS Microsystems's electronic software delivery (ESD) solution, getPlus, is a software manager that bridges the gap between the automation provider and the end user.
Dashboards Simplify Use of ERP Software
Over 20 pre-built widgets enable Jobboss users to access individual transactions and job data from the software's dashboards.
Software's Intuitive Features Aid CNC Users Programming Code
Using simple-to-understand icons and menus, Marposs Corp.'s Ready2Probe assists users in commands and codes to generate the measurement cycle within seconds based on the machine-tool part program.
Open Mind to Feature Advanced CAM Software Capabilities at Amerimold
Open Mind Technologies AG highlights the capabilities of hyperMILL CAM software in Booth 123 at Amerimold.
Machine Monitoring Software Automatically Collects Data for Easy Use
InFocus Machining is a complete machine monitoring and job tracking and analysis solution that automatically collects the machining hours of a job and each component.
Job Tracking Software Streamlines Shopfloor Processes
TST Tooling is demonstrating how its TSTracker and Estimator job tracking software streamlines the shop floor process at Amerimold 2018.
Software Demonstrations Feature Simulation Tools for Analysts
Autodesk has three demonstrations available at NPE2018 to higlight Moldflow Insight and Moldflow Helius, Moldflow for Design and Powermill.


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Our Middle School teachers offer an educational program that is exploratory and challenging, and incorporates student-generated questions and concerns. Instruction takes advantage of a wide variety of skills and abilities. Teachers respect multiple intelligences and individual learning styles. They utilize a variety of authentic and appropriate assessment measure ranging from essays, tests, and quizzes to collaborative projects, in class and online discussions, multimedia presentations, and performances.
Middle School Counselor
I completed high school in the USA and then I moved to beautiful Buenos Aires, Argentina. Two years later, I moved back to the USA, and I earned a double Bachelor's Degree in Psychology and Sociology. After working for the State Attorney's Office in South Florida for several years I joined the Broward County School System and fell in love with education.
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Science Teacher
I received my bachelor's degree and teaching credential from Sonoma State University in Northern California. Prior to teaching in Costa Rica, I taught at a charter elementary school for high-risk youth in Santa Rosa, California. I moved to Costa Rica in 2015 and worked as a middle school science and math teacher at Pan-American School for three years. In addition to my content area focus, I served on an interdisciplinary team that sought to create a caring and safe learning environment supportive of the diverse needs of all students.
Social Studies Teacher
After completing my bachelor's degree in Political Science at the University of Florida, I joined Peace Corps Costa Rica. From 2010-2013, I co-taught with English teachers in two rural schools. I helped the county of Acosta start its recycling program and trained students ages 4-65 in Microsoft Office. In 2014, I moved to my hometown Miami and joined the Teach for America 2014 cohort. I taught U.S. History, Government and Economics at Miami Central Senior High while coaching the ladies soccer team and sponsoring Environmental Club. I was also able to obtain my Master's degree in Education and Social Change at the University of Miami in 2016.
English Language Arts Teacher
My teaching passion began at the early age of seventeen. After high school, I was enrolled in the English program at Universidad de Costa Rica, Facultad de Lenguas Modernas (Modern Languages Faculty at Costa Rica University). While studying, I began teaching at a small school.
Spanish Teacher
I started to work as a teacher while studying "Ciencias de la Educación" Primaria at U.C.R., during my practice in "Escuela Nueva Laboratorio Emma Gamboa", the principal and a special committee went to a trip for a convention called "Advances in Education" which I attended representing an elementary teacher. This was the beginning of my adventure in education.
English Language Arts Teacher and Literacy Coach
After a semester abroad in Stellenbosch, South Africa I realized my passion for providing educational equality. After my return to the Midwest, USA, I earned my degree in Child and Family Studies at Northwest University in Maryville Missouri. I joined Teach for America to pursue my desire to help close the educational achievement gap in the US. Initially, I taught 6th grade reading in Kansas City, Missouri at an African-centered Middle School. While teaching, I earned my Master's Degree in Elementary Education from Rockhurst University in 2011 while working as a Reading Teacher.
I have always dreamed to be a teacher and my dreams came true. After I graduated from school, I went to University looking for my career as an educator. I completed a Bachelor's program in Teaching and Spanish and a Bachelor's program in Literature and Linguistics at National University, in Costa Rica. I also have a Master's degree in Education from Framingham College.