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of inquiry models developed in line with the. IBL approach (5-E, 7-E teaching models etc.) on the levels of conceptual understanding and some learning outcomes. • Very few applied studies in Turkey show how to use the inquiry- based approach in elementary schools. • A clear need for studies to design learning and.
Jan 11, 2018. Emphasis will be placed on effective teaching and learning practices in the Humanities, with a particular focus on inquiry, digital and design technologies, Through the inquiry process, opportunities for active and informed citizenship for the 21st century will be explored. Intended learning outcomes.
teacher-librarian or other library personnel. It provides an instructional model that can be used by all teachers, Kindergarten to Grade 12, in guiding inquiry with students. Inquiry-based learning activities can be used in various ways to accomplish the learning outcomes of Alberta programs of study: • within core programs.
Colleges Rules Com Jul 8, 2015. Students considering attending a for-profit vocational program should pay attention to how their target schools perform under the new gainful employment rules. (Getty Images). A new gainful employment rule has just gone into effect, and it could have a
You must be a current Student, Staff or Faculty member of OSU in order to purchase all Apple products. Please bring in your OSU ID with you when picking up.
Bloom's Taxonomy. by Patricia Armstrong, Assistant Director, Center for Teaching Background Information | The Original Taxonomy | The Revised Taxonomy | Why Use.
including: The outcomes of the COP21 climate change negotiations in Paris The impact of UK energy policy on emissions reduction goals Read all transcripts, written evidence and other material related to the Outcomes of Paris COP21 inquiry.
teacher and students throughout the guided inquiry process in the multilevel classroom. Guided Inquiry. The Teacher As. Reflective. Practitioner and. Keen Observer. Inquiry Process. The Student As. Reflective and. Active Learner. Formative. Assessment. • Target learning outcomes. • Focus observation. • Develop criteria.
The banks will be under pressure this week. But a government which polls this weeks shows is struggling to persuade voters it is able to affect change probably also needs some effective outcomes from this inquiry too. 1 hr ago
Jan 19, 2017. Many teachers have questions about inquiry-based learning, as it's a new pedagogy. Learn about its definition, benefits, strategies and activities.
support positive learning outcomes in various groups of students, including those under-served and under-supported by the traditional college mathematics courses. Keywords: inquiry-based learning, mixed methods, learning outcomes, undergraduate students. Introduction. Inquiry-based learning (IBL) refers to teaching.
Agile Learning Design "For the type of work we do it doesn't have to be agile. We work in hardwoods. The annual engine show in Buckley is a great reminder of the ingenuity and industrial design that has long supported agriculture. It demonstrates how much.
Welcome to Inquiry-based. explains why he thinks inquiry is a much more effective teaching strategy than. learning should be the most important outcomes.
ETS Proficiency Profile Annual Comparative Data Guide. Compare the performance of your students with those of a large group of students at other institutions.
Jun 17, 2016. Domain theory reveals that although cli- mate change is a complex and difficult phenomenon to learn and teach, versa- tile and recurrent communicative inquiry learning methods help to achieve bet- ter learning outcomes. Keywords: design research, inquiry, communicative approach, practical knowledge.
What is inquiry-based learning? An old adage states: "Tell me and I forget, show me and I remember, involve me and I understand." The last part of this statement is.
Today's guest blog is co-authored by Jenni Donohoo, a Provincial Literacy Lead in the Curriculum and Assessment Policy Branch in the Ontario Ministry of Education. inquiry is one such design that not only makes a difference in regard to.
What is a "big idea"? An idea is "big" if it helps us make sense of lots of confusing experiences and seemingly isolated facts. It's like the picture that.
The Department of the Environment is "neutral to the outcome" of a public inquiry into an attempt by George Best Belfast City Airport to change part of its planning agreement. The claim was made by a lawyer for the department on.
It came as the Education Department launched a major crackdown on corruption. Department secretary Gill Callister told the inquiry on Tuesday that $12.5 million remained in banker schools, and the department was trying to claw back.
It came as the Education Department launched a major crackdown on corruption. Department secretary Gill Callister told the inquiry on Tuesday that $12.5 million remained in banker schools, and the department was trying to claw back.
Cooperative Teaching [Teacher Tools] [Case Studies] Co-teaching is a model that emphasizes collaboration and communication among all.
IN-SERVICE PROFESSIONAL DEVELOPMENT IN INQUIRY BASED. SCIENCE EDUCATION – OUTCOMES AND CHALLENGES. National and international reform efforts demand a reversal of school science teaching from mainly deductive to inquiry based methods. However, transforming teacher practice is a long-term.
Habib Ullah's family will launch civil action against police after the 'disappointing outcome' of the inquiry into the.
This study explored the use of a scaffolded version of lesson study to develop professional teaching knowledge for problem-based historical inquiry among three 4th.
Engage: This phase of the 5 E's starts the process. An "engage" activity should do the following: Make connections between past and present learning experiences ; Anticipate activities and focus students' thinking on the learning outcomes of current activities. Students should become mentally engaged in the concept, process, or skill to be.
Choosing in advance a specific effect that is a predicted result of the inquiry process and testing whether over time there were any detectable changes in practice, increases confidence that any outcomes might be plausibly attributable in some way to the teacher inquiry intervention (Bootzin & Bailey, 1985). In addition.
Science Literacy Skills and Confidence," International Journal for the Scholarship of Teaching and Learning: Vol. 3: No. design, and included developments such as peer-teaching, problem and inquiry-based learning. In the. Since we recognized that student learning outcomes may be influenced by a confluence of.
New Delhi: The Centre on Friday said it was awaiting the outcome of an inquiry being conducted into the incident of illegal stay of a woman posing as IAS officer in the country's premier training Academy in Mussoorie. "This is the case.
Educational goals have shifted from curricula content to curricula outcomes. Beyond the mastery of content (which may quickly become outdated), the development of specific skills (critical thinking) and innovative responses to problems are now required of advanced practice nurses. Inquiry-based learning ( IBL) offers an.
Aug 17, 2017. So in this post – drawing upon the work of (DeLuca, Bolden, & Chan, 2017) – we will identify the factors that both enhance and inhibit teacher experiences of collaborative inquiry. We will then consider teacher perceptions of the significant outcomes – for both teachers and students – of collaborative inquiry.
Student outcomes of inquiry-based teaching and learning were explored through student-report. Participants were six teachers and their 181 students in grades 9.
Habib Ullah's family will launch civil action against police after the 'disappointing outcome' of the inquiry into the.
Historical inquiry attempts to get to the "essence" of the specific curricular outcomes, allowing students to have choice in the topic(s) they examine, the process they undertake, and how they represent their learning and new understandings. By using a broad-based, open-ended "essential question," teachers allow for.
In this section, teachers can access digital literacy classroom resources aligned with curriculum outcomes set out by their province or territory.
SOLO Taxonomy SOLO Taxonomy (structure of observed learning outcomes) provides a simple, reliable and robust model for three levels of understanding – surface deep.
New Delhi: The Centre on Friday said it was awaiting the outcome of an inquiry being conducted into the incident of illegal stay of a woman posing as IAS officer in the country's premier training Academy in Mussoorie. "This is the case.
And so, while each student in the class has selected his or her own inquiry focus, all students are exploring this same issue. But in addition to skills and content outcomes, inquiry involves dispositions such as curiosity, flexibility, empathy, perseverance, skepticism. These must be modeled and demonstrated by the teacher if.
CILASS employs the same evaluation methodology developed and used by Learning and Teaching Services at the University of Sheffield, intended to be a collaborative and participatory approach. It is based on a combination of Theory of. Change (Connell & Kubisch, 1996) with Enabling, Process and Outcome ( EPO).
Ms Gotlib said such an inquiry needed to range beyond the issue of abuse to examine educational outcomes for students with disabilities. "We've been saying for years that the present education system just isn't adequately meeting the.
Learning Outcomes of Project-Based and Inquiry-Based Learning Activities 1Mookdaporn Panasan and 2Prasart Nuangchalerm. The inquiry teaching.
The fundamental purpose of the Teaching as Inquiry cycle is to achieve improved outcomes for all students. Less obviously, but very importantly, the cycle is an organising framework that teachers can use to help them learn from their practice and build greater knowledge.
To be of real spiritual value, inquiry must be alive and fresh. Regardless of what we remember or have discovered from the past, each time we truly inquire, we return to not knowing what the outcome will or should be. No doctrine is needed.
Mr G B Prabhat is Founder and CEO of Anantara Solutions. He is a prolific writer of business articles dealing with competitiveness, IT, business processes, organisational culture and leadership. His book on managing in the new world.
Teacher behaviors and student outcomes JRST published several related studies using interaction analysis techniques to examine inquiry-based instructional settings. Shymansky & Matthews (1974) was among the first. The basic idea behind the study was to code teacher behaviors (with the teacher providing more or less.
Many teachers and schools are heading down the path of inquiry based learning. But what does this mean? Is it one of the effective teaching strategies to use in.
Inquiry learning has been used as a teaching and learning tool for thousands of years, however, the use of inquiry within public education has a much briefer history. Ancient Greek and Roman educational philosophies focused much more on the art of agricultural and domestic skills for the middle class and oratory for the wealthy upper class.
Chris Krogh is affiliated with Home Education. or evidence of successful home education outcomes. These removals appear ideologically driven and fundamentally change the message communicated by the report. It seems that even in.
The Centre on Friday said it was awaiting the outcome of an inquiry being conducted into the incident of illegal stay of a woman posing as IAS officer in the country's premier training Academy in Mussoorie. "This is the case of forgery and.
Read chapter 8 Supporting Inquiry-Based Teaching and Learning: Humans, especially children, are naturally curious. Yet, people often balk at the thought o.
May 21, 2011. Through the application of these principles, implementation of teaching and learning practices improve resulting in better student outcomes. The first section of this paper describes a cycle of inquiry and knowledge-building derived from the evidence in the synthesis of the research on teacher professional.


text: A pending listing indicates a seller has accepted a suggestion from a customer. In some cases, the vendor will accept backup delivers.I'm quick Therefore the duct get the job done did not bother me in the slightest degree, but If you're over five' seven" you will have to make sure to duck when you need to use the bathroom. This is a peaceful Attrac

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Loot : How to Steal a Fortune. / Jude Watson.
Electronic resources
View other formats and editions
Record details
- ISBN: 9780545677363 (sound recording)
- Physical Description: 1 online resource (6 audio files) : digital
- Edition: Unabridged.
- Publisher: New York City : Scholastic Audio, 2014.
Content descriptions
|General Note:
|Participant or Performer Note:
Narrator: Michael Crouch.
|Summary, etc.:
Hijinks, heists, and high-octane action in Jude Watson's new middle-grade blockbuster!On a foggy night in Amsterdam, a man falls from a rooftop to the wet pavement below. It's Archibald McQuinn, the notorious cat burglar, and he's dying. As sirens wail in the distance, Archie manages to get out two last words to his young son, March: "Find jewels."But March learns that his father is not talking about hidden loot. He's talking about Jules, the twin sister March never knew he had. No sooner than the two find each other, they're picked up by the police and sent to the world's worst orphanage. It's not hard time, but it feels like it.March and Jules have no intention of staying put. They know their father's business inside and out, and they're tired of being pushed around. Just one good heist, and they'll live the life of riches and freedom that most kids only dream about....Hold on to your pearls, because this summer, the world's youngest criminal masterminds are coming for you.
|System Details Note:
Requires OverDrive Listen (file size: N/A KB) or OverDrive app (file size: 199930 KB).
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Next Meetup
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Does Katy Perry's 'Roar' Sound Like Sara Bareilles' 'Brave'?
Katy Perry 'Roar-ing' into fall with a massive hit on her hands and some are thinking that 'Roar' sounds just like Sara Bareilles' 'Brave.' What do you think?
I love both songs and I do think that 'Roar' sounds extremely close to 'Brave.'
Watch Sara Bareilles 'Brave'
Watch Katy Perry's 'Roar'


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Newsletter Archive
LimitState software used by organizations in 30 countries
LimitState now has industry customers in 30 countries worldwide, demonstrating the broad appeal of our innovative engineering analysis and design software products.
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LimitState software is also used for teaching and research throughout universities in numerous other countries.
Published: 2nd Jan 2013


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|Label: ARTSMAGIC
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Home » Clinical Trials » Location » Canada
Red Deer, Canada Clinical Trials
A listing of Red Deer, Canada clinical trials actively recruiting patients volunteers.
Found (14) clinical trials
SODIUM-HF: Study of Dietary Intervention Under 100 MMOL in Heart Failure
SODIUM-HF is a multicenter clinical trial in ambulatory patients with chronic HF to evaluate the efficacy of a low sodium containing diet on a composite clinical outcome composed of of all-cause mortality, cardiovascular hospitalizations and cardiovascular emergency department visits. The hypothesis of this study is that patients following a low-sodium ...
0.0 miles
Improving the Stewardship of Diagnostic Imaging Resources in Alberta Emergency Departments
Background Imaging technology for the rapid diagnosis of medical conditions is an indispensable tool in the emergency department (ED). However, increasing and inappropriate use of costly and potentially dangerous imaging is a growing healthcare concern. The long-term health risks of radiation exposure, and the resources consumed by increased use, pose ...
0.0 miles
AMPLEX Ankle Fusion
To demonstrate that AMPLEX is non-inferior to autogenous bone graft (ABG) for bone fusion in a population indicated for single, double, or triple hindfoot arthrodesis or ankle arthrodesis surgery with supplemental graft material.
0.45 miles
SPIRIT 1: Efficacy and Safety Study of Relugolix in Women With Endometriosis-Associated Pain
This study is an international phase 3 randomized, double-blind, placebo-controlled efficacy and safety study to evaluate 24 weeks of oral, once-daily relugolix (40 mg) co-administered with either 12 or 24 weeks of low-dose estradiol (1.0 mg) and norethindrone acetate (0.5 mg), compared with placebo. Approximately 600 women with endometriosis-associated pain ...
A Study to Evaluate the Effect of Dapagliflozin on Renal Outcomes and Cardiovascular Mortality in Patients With Chronic Kidney Disease
This is an international, multicentre, event-driven, randomized, double-blind, parallel group, placebo-controlled study, evaluating the effect of dapagliflozin versus placebo, given once daily in addition to standard of care, to prevent the progression of chronic kidney disease (CKD) or cardiovascular (CV)/renal death.
Pemafibrate to Reduce Cardiovascular OutcoMes by Reducing Triglycerides IN patiENts With diabeTes (PROMINENT)
A multi-regional clinical trial with participating sites planned in the following countries pending approval from the applicable oversight authorities: Argentina Brazil Bulgaria Canada Colombia Czech Republic Denmark France Germany Hungary India Israel Japan Mexico Netherlands Poland Romania Russian Federation Slovakia South Africa Spain Ukraine United Kingdom United States
Study to Evaluate the Safety and Efficacy of Relamorelin in Patients With Diabetic Gastroparesis Study 02
This study will evaluate the safety and efficacy of Relamorelin compared to placebo in patients with diabetic gastroparesis. Patients will report daily severity scores of their diabetic gastroparesis symptoms.
Effect of Efpeglenatide on Cardiovascular Outcomes
The estimated study duration per participant is up to approximately 36 months.
INfluenza Vaccine to Effectively Stop Cardio Thoracic Events and Decompensated Heart Failure
Influenza leads to significant morbidity and mortality, particularly in patients with cardiovascular disease. Influenza-related death is more common in patients with cardiovascular disease than any other chronic health condition. Influenza infection has been temporally associated with acute cardiovascular events, such as acute coronary syndrome and acute heart failure. Due to ...
A Study to Evaluate the Efficacy and Safety of Pimodivir in Combination With the Standard-of-Care Treatment in Adolescent Adult and Elderly Non-Hospitalized Participants With Influenza A Infection Who Are at Risk of Developing Complications
This double-blind (neither researchers nor participants know what treatment participant is receiving) study will evaluate efficacy/safety of pimodivir in combination with SOC treatment versus placebo in combination with SOC treatment in adolescent (13 to 17 years), adult (18 to 65 years), and elderly (greater than [>] 65 but less than ...


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Among the different optical modulator technologies available such as polymer, III-V semiconductors, Silicon, the well-known Lithium Niobate (LN) offers the best trade-off in terms of performances, ease of use, and power handling capability [1-9]. The LN technology is still widely deployed within the current high data rate fibre optic communications networks. This technology is also the most mature and guarantees the reliability which is required for space applications [9]. In or der to fulfil the target specifications of opto-microwave payloads, an optimization of the design of a Mach-Zehnder (MZ) modulator working at the 1500nm telecom wavelength was performed in the frame of the ESA-ARTES "Multi GigaHertz Optical Modulator" (MGOM) project in order to reach ultra-low optical insertion loss and low effective driving voltage in the Ka band. The selected modulator configuration was the X-cut crystal orientation, associated to high stability Titanium in-diffusion process for the optical waveguide. Starting from an initial modulator configuration exhibiting 9 V drive voltage @ 30 GHz, a complete redesign of the coplanar microwave electrodes was carried out in order to reach a 6 V drive voltage @ 30GHz version. This redesign was associated to an optimization of the interaction between the optical waveguide and the electrodes.
Following the optimisation steps, an evaluation program was applied on a lot of 8 identical modulators. A full characterisation was carried out to compare performances, showing small variations between the initial and final functional characteristics. In parallel, two similar modulators were submitted to both gamma (10-100 krad) and proton irradiation (10.109 p/cm²) with minor performance degradation.
During past years, innovative payload concepts based on photonic technologies were investigated by Thales Alenia Space [10-11]. Several architectures were elaborated covering different application cases including (but not limited to) flexible analogue repeaters based on a photonic centre section and photonic receiver front-ends for advanced antennas allowing digital beam forming. Such architectures rely on photonic subsystems able to assist, complement, replace and/or extend the capabilities of conventional RF subsystems including:
• Optical generation/distribution of microwave Local Oscillators (LO)
• Photonic RF frequency up and down conversion
• Routing of μ-wave signals in repeaters
• Photonically assisted beam forming networks
• Optical sampling for analogue to digital conversion
In this context, optical modulators play a key role in the implementation of such functions.
For instance, the optical distribution of LO's requires to produce a microwave LO signal, under optical form, with low phase noise and optical power high enough to be deliveredto a large number of receivers while meeting system requirements. The transfer of a high-frequency signal onto an optical carrier through direct modulation of the laser current is not applicable at high frequencies and requiresexternal electro-optical intensity modulators. In particular, optical double sideband modulation with carrier suppression (DSB-CS) is a LO generation technique making use of a high-power CW laser and a MZ electro-optical modulator (EOM) biased at minimum optical transmission, as shown in Figure 1. When the modulator is driven by a microwave signal at ωLO/2 frequency, the optical output signal mainly contains the first two modulation side-bands. Optical heterodyning at the photo receiver generates a microwave signal at the ωLO frequency.
Photonic RF frequency mixing for both up and down conversion of microwave signals can be achieved optically by means of EOMs. The sinusoidal transfer function of MZ modulators make them attractive as mixers. In addition to a very wide bandwidth and an infinite LO to RF input port isolation, a remarkable feature of electro-optical mixing is its ability to perform simultaneously multiple frequency-conversions. In this concept, shown in Figure 2, the optical mixer is fed by several optical LO's through wavelength-division-multiplexing (WDM). In this way, the RF signal at the ωRF frequency driving the modulator is mixed to the different LO's and frequency-converted to several signals at various ωIF frequencies. The most critical requirements for the EOM in previously depicted applications are low optical loss, high dynamic extinction ratio, high optical power handling capability and low RF half-wave voltage. More exhaustively, an efficient optical modulator shall, in particular:
• operate in the high frequency domain (to comply with Ka band requirements and above),
• operate under low driving power (to lower the power consumption budget of the overall system)
• exhibit low optical insertion loss (to improve RF gain and noise figure performance),
• handle high optical input power (to improve RF gain and noise figure performance),
• feature good linearity (to meet the requirements of analogue systems),
• come in small size (to accommodate in systems where size is critical, e.g. phased array antennas),
• withstand the space environment constraints.
The Table 1 hereafter summarizes typical specifications for optical intensity modulators used in these applications.
Table 1:
Typical modulator specifications
|Operating wavelength
|1520 – 1600 nm
|Maximum input optical power handling
|200 mW
|Optical insertion loss
|≤ 3 dB
|RF operating frequency
|Up to 40 GHz
|RF driving voltage (or power) @ 30 GHz (Note 1)
|≤ 4 V (≤ +16 dBm)
|Dynamic extinction ratio
|> 20 dB
|Linearity : carrier-to-3rd intermodulation (Note 2)
|> 60 dBc
|50 ohms
|RF return loss (in the band)
|> 15 dB
|Optical fibre input/output
|PMF / PMF or SMF (Note 3)
|< 8 cm3
|< 20 g
|> 15 years
(Note 1) Peak-to-peak RF voltage (or power) for 100% modulation at 30 GHz, i.e. half-wave voltage for Mach-Zehnder modulator.
(Note 2) Carrier-to-Intermodulation ratio, with 2-tone @ 30 GHz, and power per tone 25 dB below RF drive power
(Note 3) Polarisation-maintaining fibre / Polarisation-maintaining fibre or Single-mode fibre
It is practical in microwave analogue applications to use the following figure of merit (FoM) :
Where αdB is the optical insertion loss (dB), and VπRF is the effective half-wave voltage (V) at the operating frequency. One should notice that the RF gain of a non-amplified link is directly proportional to this FoM, and that the RF noise figure is inversely proportional to this FoM. The factor of merit described here will be a guideline in the following description. We describe in the next paragraphs the MZ modulator.
A previous assessment of different modulator technologies highlighted the suitability of LN modulator as a mature and promising technology for space applications [9].
Figure 3 shows a conventional broadband modulator. It is constructed from a Mach-Zehnder waveguide integrated in a LN substrate. Depending on the aimed performances, two crystals orientations are possible. In many cases, for thermal stability reasons, the crystal orientation is X-cut. The reason is that the Z-cut orientation is sensitive to pyroelectric effects requiring thus special antistatic layers in the fabrication to avoid failures due to temperature variations. Single drive Z-cut modulators are also characterized by chirp which can be a drawback for DSB-CS modulation.
Two technologies can be used for the waveguide fabrication. However, the technology called Titanium indiffusion waveguide (TI-WG) is preferred to proton exchange for thermal stability reasons. For an amplitude or intensity modulator, the design of a waveguide is the Mach-Zehnder configuration with one input waveguide, a Y-branch section for spatial separation of the input beam in two waves, two parallel waveguide arms, a second Y-branch section and an output waveguide playing the role of modal filter.
Coplanar waveguide microwave electrodes are patterned in order to allow the electro-optic interaction between the electric signal and the optical light field propagating into the waveguide. A silica buffer layer is introduced between the electrodes and the waveguide in order to achieve the 50 Ω characteristic impedance. The thickness of the buffer is selected in order to reach the phase matching condition, i.e. the microwave effective index is equal or very close to the optical effective index. Moreover, the thickness of the gold electrodes is adjusted in order to reduce the conductor loss. Finally, the gap between the central line and the lateral ground plane is designed to optimize the driving voltage.
In order to reach the targeted performances required in microwave photonic payloads, described in section I, it was necesary to improve the initial version of the Photline broadband analog modulator. This initial version exhibited a half-wave voltage in excess of 9 V at 30 GHz and the RF and DC electrodes were separated. Following multiple microwave and optical simulations, a new version was designed. One single RF electrode allowed driving both the RF and DC voltage via a dedicated bias tee termination. The CPW electrodes and optical waveguide designs were deeply remodeled in order to ensure an effective driving voltage reduced by 30% while keeping a minimal footprint. The housing was also improved in order to reach a smaller form factor (85 mm long packaging while previous version was 100 mm long).
To validate the new modulator design, prototypes were submitted to a functional test campaign and thermal tests were carried out to assess their stability. The measured low frequency half-wave voltage on the RF electrodes was typically 4.1 V. The S21 electro-optic response at 30 GHz in the Ka band was -4 dB. The corresponding effective half-wave voltage of 6.5 V is thus expected to reach the aim target of 6-7 V.
The X-Cut and TI-WG devices showed optoelectronic results in compliance with the original target. Their high stability under temperature variations was also confirmed. The devices were hermetically sealed and submitted to 6 steps of temperature ranging from -30°C, -20°C, 0°C, 20°C, 40°C & 70°C. Each steps lasted 120 minutes. The insertion loss (IL) variations (Figure 4, blue line) and the bias voltage drift (Figure 5, blue line) were recorded and plotted for each of them, while the temperature variations are represented by a red dashed line.
The tested modulators exhibited a very high bias voltage stability over the whole temperature range, with peak to peak drift of 3 V for the worst case (1 V in the case of Fig. 5) while at stable temperature, the drift was very low. In all cases, the insertion loss remained stable (< 0.5 dB) over the whole temperature range.
Based on this optical modulator prototype dedicated to microwave photonic payloads, an evaluation based on space applications consideration was launched. Next paragraphs describe the adopted test plan.
In order to fully assess the suitability of this new modulator design for the previously mentioned space applications, 8 identical samples were fabricated by Photline and evaluated through a functional and environmental test campaign. They were screened and then submitted to an initial characterisation. Two additional samples (#1946-12 & #1946-14) of similar technology (X-cut, Ti-WG) were used for irradiation (gamma & proton) tests.
The test plan sequence for the different samples is shown in table 2, and it can be summarised as follows:
• The sample (5246-18) was chosen as reference modulator and did not pass any of the tests. This sample was submitted to destructive physical analysis (DPA) at the end.
• The samples (#4816-11 & #6243-04) were submitted to mechanical tests only, i.e. SRS (Shock Response Spectrum), sine and random vibrations.
• The sample #4816-18 was submitted to the thermal vacuum test only (0°C 70°C).
• The samples #5246-17 was submitted to endurance test only (2000hrs)
• The sample #5246-06 was submitted to both mechanical tests and thermal vacuum tests.
• The sample #5246-13 was submitted to both thermal vacuum tests and endurance tests.
• The sample #5246-11 was submitted to the three sequences of mechanical tests, thermal vacuum tests and endurance tests then final DPA for comparison with the reference modulator #5246-18.
Table 2.
Test plan sequence and samples distribution (T: test, R: reference)
The initial and final characterisations were carried out by Thales Alenia Space, while intermediate characterisations were carried out by Alter Technology in collaboration with Universidad Politécnica de Madrid.
The measured characteristics were the following:
• Static E/O response, based on the output optical power measurement versus DC bias voltage (no RF signal applied). It provides optical insertion loss, DC Extinction Ratio and DC half wave voltage
• RF half-wave drive voltage (VπRF) by optical power measurement at minimum transmission. The RF frequency signal is set at 30 GHz. 3rd-order interception point and RF voltage measurement (VπRF) at 30 GHz based on the two-tone measurement method.
• Optical bandwidth, based on the output optical power measurement versus wavelength, at DC bias voltage (no RF signal applied) for maximum transmission at 1550 nm.
In next paragraphs, we report the results obtained on the different samples after each tests and we will check the main drift thus obtained. We focus in particular on the variations of the insertion loss and of the effective half wave drive voltage at 30 GHz, in order to conclude on the stability of the aimed FoM at the end of this space assessment.
Irradiation test results
The irradiations tests were carried out in two steps. In the first step, modulators were exposed to gamma radiations with a cumulated dose up to 100 krad with intermediate characterisation and followed by thermal annealing steps. Table 3 summarizes the main variations of insertion loss and drive voltage. The second step was dedicated to proton radiations with doses up to 1010 p/cm2. Table 3 summarizes the corresponding variations of drive voltage and insertion loss.
No major degradation of insertion loss (exceeding 1dB) and VπRF were observed after the two irradiation steps (gamma and proton).
Table 3.
IL and VπRF drifts of samples # 1846-12 and 1946-14 Gamma irradiation followed by thermal annealing steps, then Proton radiation
|10 krad
|30 krad
|60 krad
|100 krad
|annealing 24h
|Annealing 168th
|Annealing 70°C 168h
|Proton 5×109p/cm2
|Proton 5×109p/cm2
|Proton 1×1010p/cm2
Overall test results
Fig. 6 shows the variations of the key parameters (Insertion loss IL and drive voltage VπRF) measured after each main steps (mechanical shocks, sine vibrations, random vibration, thermal vacuum, endurance) with all intermediate characterisations.
During the environmental test campaign no deleterious effect was observed. In particular, thermal and mechanical tests were successfully passed by the modulators tested: no dramatic variations of the main parameters (IL & VπRF) were measured. However, thermal vacuum tests highlighted different behaviours among modulators submitted to this test possibly due to slight differences in the design. All samples were fully operational after the complete mechanical series, with very good stability on the DC Vπ and RF Vπ @30 GHz. Slight variation of IL parameter after random vibration could be observed on some samples.
Following the environmental tests, a final functional test campaign was performed in order to evaluate the variations of the FoM defined in (1) between the beginning and the end of the full test campaign. The same parameters as during the initial functional test were measured. Fig. 7 summarises the FoM variations of the samples on a chart taking into account both critical parameters (IL and VπRF).
The design of the modulators allowed reaching low insertion loss (2.6 dB at best) concurrently with relatively low driving voltage (6V). Thus, the reached figure of merit meets the requirements of photonic microwave payload in particular LO generation technique. The prototypes were submitted to a space assessment. The final characterisation showed no significant drift, in particular relative to insertion loss. The average insertion loss variation was found to be -0.12 dB while the average driving voltage drift was found to be -0.125 V when comparing the initial and final characterisations performed at 30 GHz.
This evaluation carried out on new multi GigaHertz optical modulators, anticipates a full space qualification process. The low drift of physical parameters after irradiation, vacuum thermal cycling in particular confirms the suitability of this technology of optical modulators to operate in space with a proven level of reliability within future microwave photonic payload.
This work was supported by the European Space Agency (ESA) under the ARTES 5 contract n°20101/06/NL/Sfe – Multi-Gigahertz Optical Modulator of Very Low RF Driving Power.
The author thank the European Space Agency and especially Nikos Karafolas, as technical officer of this activity, as well as national space agencies (CNES and INTA), for their support and collaboration during this project.
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text:
Giles Foden, the prizewinning author of The Last King of Scotland, delivers a mesmerizing blend of fact and fiction in this novel about how human beings deal with uncertainty.
Five days before D-day, a team of Allied scientists is charged with making an accurate weather forecast for the landings. Henry Meadows—a young math prodigy from the Met Office—is sent to Scotland to uncover Wallace Ryman's revolutionary system for understanding turbulence, one of the last great mysteries of modern physics. But Ryman is a reclusive pacifist who stubbornly refuses to divulge his secrets, and when Henry meets Gill—Ryman's beautiful wife—events, like the weather, begin to spiral out of control.
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About the Author
Giles Foden was born in 1967 in England and spent his youth in Africa. Between 1990 and 2006 he worked as an editor at The Times Literary Supplement and The Guardian. In 1998 he published The Last King of Scotland, which won the Whitbread First Novel Award and was later made into a feature film. The author of two other novels and also a work of narrative nonfiction, in 2007 he was appointed professor of creative writing at the University of East Anglia, in Norwich. He lives in Norfolk, England.
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By the time we reached glasgow it was obvious that there was no chance of travelling any further that day. We sat down to spuds with mince and onions, followed by whisky and a game of poker in front of a coal fire. If I'm not careful, I thought, as the cards slapped onto the table, I could lose the whole afternoon. I resolved not to—but within minutes the whisky and the warmth had drained all the willpower out of me.
Over the card play, as coals glowed in the hearth and a waitress in an apron and bonnet supplied us with ice for the Scotch, I listened as Krick told me his remarkable life story. I had taken an unlikely route into meteorology, but his was far stranger. After taking a physics degree at the University of California he worked as a disc jockey, then as a runner for a company of stockbrokers.
"Chapman de Wolfe and Company,"he said,pronouncing it "Volf " in the German way. "As you can imagine, my services were dispensed with pretty rapidly after the Crash in 'twenty-nine. Though I missed the worst of it on my own account."
"How?" I asked, leaning forward.
He grinned, slicking his hair back. "I devised a system calibrating financial fluctuations against background randomness, according to certain physical principles. Things have changed a bit since then, but I still use the same basic idea."
Krick's theory of stock-market cycles had begun as an innocent intellectual recreation, or so he said, but in years to come he successfully played the markets using his system. The Wall Street Crash was no accident, he maintained. It was a necessary piece of information within a larger story. Ryman, who had none of Krick's hucksterism, would have agreed. There are no accidents. Every so-called "accident," every piece of turbulence, is part of a sequence, bigger or smaller, whose scale you cannot see. At least, you don't see it until it's too late, and then you start to panic, because you realise how foolish was your original fantasy of understanding.
During the Depression Krick sold pianos and worked as a jobbing concert pianist for the NBC Orchestra. He was also a radio disc jockey for a while. Eventually he found his way back to university, studying meteorology under Theodore von Kármán and Robert Millikan at Caltech in Los Angeles. It was uncanny to hear about these giants of meteorology in a Glasgow hotel—stranger still to do so with a glass of whisky in one hand and a busted flush in the other.
As the talk flowed, I drank more and more. I won a couple of pots. So did Krick, leaning his big face forward as he collected. The other Americans won one apiece. As the cards were dealt and shuffled and stacked, the smoke from our cigarettes and cigars swirled up the oak panelling, with its pictures of sporting scenes and moody Highland cattle. How well I would come to know their glowering stares.
Krick told more anecdotes as we played. "Goering tried to lure back von Kármán to Europe to head up the Luftwaffe's weather forecasting," he said. "Von Kármán refused, simply sending Goering a drawing of his Jewish profile." We all laughed. It was a meteorologists' joke, a "profile" being a technical term in weather forecasting.
As Krick talked I slowly began to realise the anecdotes were diversion tactics. The tales were intended to distract his opponents from their game—and it was working. All the time he was recounting his experiences, or expounding pet theories, he was taking money off us.
The diverting stories continued. The duo had met at Caltech. Then Krick had joined an airline, as had Holzman, who became chief meteorologist for American Airlines. They began swapping tales about the aviation industry.
"I used to get in trouble in that first job," Krick drawled, showing another hand. A pair of deuces—plus another pair of deuces. Four of a kind against my full house, and there he was scooping up our money again."They hadn't heard of weather fronts then,and hated me drawing them on the charts. But obviously it was more useful for the pilots. Then they could see where the action was coming from. Predictable as a corny movie."
"Irv worked in Hollywood," chipped in Holzman. "He was weather prophet for Gone with the Wind."
Krick grinned as he added our money to his stack. "I picked the night they burnt Atlanta. It had to be a clear one."
"Another time, he advised Bogart on the weather for the Ensenada yacht race," said Holzman.
"I flubbed that. Bogie never got to Mexico. He stayed in U.S. waters. A dead calm."
Holzman laughed. "Will you go back to it, Irv, when the war's over?"
"I doubt it. I was forecasting for the citrus industry before I got called up. Reckon I'll get back into it. That's where the money is."
"Commercial forecasting," nodded Holzman.
"Transporting airplanes is another good one," added Krick. "Forty planes going from A to B, you don't wanna get that wrong. One of my first duties in the air force in this war was to pick the days when our guys could fly safely across the Atlantic."
"Days with minimum turbulence?" I asked.
"Oh no," said Krick. "Pick those days and our friends in the Luftwaffe would be waiting. It was more a case of just enough turbulence." He produced a cigar from under the table and, as prelude to another tale, blew a near-perfect smoke ring over my head . . .
It has always struck me as fate that I met those two at the beginning of my working life. From my Cambridge ivory tower I have followed their careers with interest since the war, now and then bumping into one or the other of them on trips to America. They became sort of alter egos for me, standing for all the possibilities I shut off when I chose withdrawal into academic life.
Later in the war Holzman would work on the weather forecast for the atom bomb at Los Alamos. He stayed in the U.S. Air Force for his entire career, becoming a general and commander of the USAAF Research Laboratory. He was involved in virtually every major phase of research into missile and space systems, all through the Cold War. His security clearance was cosmic, so I didn't get to see him much.
Krick, as he indicated during that poker session, would pretty much found the new industry of selling the weather. Cotton growers wanting to know what the harvest will be like. The Edison Company having difficulties with storms knocking out power lines. The California Division of Highways worrying about snow in the mountains. The Brooklyn Dodgers wanting advice on whether they should buy rain insurance for an important game. Loggers, fruit growers, the managers of hydroelectric schemes...
Krick pursued all this and more. He was weather forecaster for the 1960 Winter Olympics and, the following year, for the inauguration of President Kennedy. But his biggest thing was cloud-seeding, which involved modifying weather by dispersing chemicals, usually silver iodide, or dry ice, into clouds to induce precipitation.
Krick got into this still-controversial practice in a major way, selling thousands of ground-based generators to farmers all over the U.S. These machines, rocketing crystals into the reluctant sky, were all controlled by radio from a complex in Palm Springs, California, where Krick himself still lives in a Moorish-style mansion in the shadow of Mount San Jacinto.
I went to visit him there once—the place had marble floors—and he was extremely hospitable, serving up frozen margaritas. But to the U.S. Weather Bureau he became a kind of bête noire. There were accusations of quackery and exploitation. He was always very charming to me, and I never brought up something which troubled my colleagues: that he may have been the source of the rumours, still current to this day in the U.S., that the British teams "failed" in their predictions for Overlord— and that D-Day was saved by Krick himself. He even maintained, somewhat astonishingly, that it would have been better to have gone a day earlier after all. I let it pass.
This was the extravagant future which lay ahead of my poker opponents. I drank far more than I should have done and lost more money than I could afford. Some time in the early hours I staggered up to bed, wallet half emptied, shoelaces trailing, mounting unsteadily a staircase, the steps of which seemed to have been frustratingly rearranged, before losing myself in a warren of interconnecting, treacherously carpeted corridors and the hiding-places of mops and buckets and boiler-room pipes. I suppose I must have booked a room in the course of that long afternoon which had stretched into evening, and eventually found my way to it, but I can't remember either.
EARLY ON THE THIRD DAY I SET OFF set off on the motorcycle to Dunoon, in order to report to Whybrow. I had left it rather late, telling myself the important thing was to ready myself for the encounter with Ryman. Presumably Sir Peter had given Whybrow some indication that I was also doing work other than local observations.
Feeling the wind-chill on my face and hands, I rode alongside the water, past the row of large loch-front houses which constituted Kilmun itself, passing an old church with a tower in its graveyard. I then turned left under bumpy green hills, travelling for several miles (and at one point falling off) until I reached Dunoon.
It was a busy place. As well as local residents there were an awful lot of people in one sort of uniform or another. Colonial troops and Americans as well as British servicemen. On asking where I might find HMS Osprey, where Sir Peter had said Whybrow was based, I found it to be one of the shore-based establishments—in this case a former convalescent home—which the navy insists on calling a ship. The floor is referred to as the deck, right starboard and left port. Even to leave by the front door is to take a liberty boat.
As I arrived, a flag-raising ceremony was taking place outside the building, complete with buglers and ratings in blue and white uniforms. The event was unpopular with the townsfolk as it brought the main road to a standstill.
We stood waiting and watching, our way barred by sentries with rifles. At the crucial moment, much to the amusement of civilian onlookers, an old fellow in a blue jersey, who was selling fish and oysters from a wheelbarrow, shouted out, "Loch Eck herrings, fresh Loch Eck herrings!"
Once the performance was over, it turned out my wait had been for nothing, as on gaining entrance I learned that the Met station at Dunoon was actually inland rather than on Osprey itself. Yet even this second site was still conceived as part of the "ship."
I remounted my motorbike and eventually found, on the outskirts of the town, a group of Nissen huts dotted around an old white-painted farmhouse. There was a cookhouse and a washhouse and a hydrogen shed (formerly a grain barn), some dormitories and not much else. The conditions were quite primitive. There was mud everywhere. The sight of it made me shudder.
Gordon Whybrow was bald and short-sighted, with a pair of thick-lensed spectacles balanced on the end of his long, thin nose. I first found him in the Ops Room, as the farmhouse drawing room had been rechristened. He was wearing RAF uniform, like all Met staff who have been conscripted, even if they're actually working in another branch of the services, as he was on Osprey. I was still a civilian employee at this stage.
Bent over a desk bearing the large typewriter on which, I presumed, his letter to me had been written, he was studying another machine, or part of it. I recognised it as the switching mechanism on a new type of radiosonde.
Three inflated red balloons bumped on the ceiling of the room, their strings draping over Whybrow as he peered at the device. Behind him, on a large board on the wall, a Waaf was plotting combined readings. A slight brunette, she was reaching up for strings—held in place by brass "mice"—which showed the directional lines of balloons released from different stations.
Little red flags marked the positions of weather ships in the Atlantic, the Channel and the North Sea, while lines of green flags marked the tracks of the met recs, the meteorological reconnaissance flights which took off from airfields all over Britain each morning.
Another Waaf, plumpish with short fair hair, was kneeling on the floor, reading data to her colleague as the teleprinter roll spilled down. Her chubby face was dotted with freckles. She was the only person in the room to notice my entrance, smiling pleasantly and brushing a hand against her skirt as if doing so would compensate for the awkwardness of kneeling.
"You have to set the switch sequence before you put on the windmill," I said to Whybrow's bald head. He looked up with a face full of surprise, swiftly followed by irritation, whether at my remark, which I suppose was a bit know-it-all, or simply my arrival I could not tell.
"Henry Meadows. The director probably mentioned . . ."
"Ah," said Whybrow, straightening. "There you are at last. Our man of mystery. I noticed you had hooked up the teleprinter yesterday. Why has it taken you so long to report in?" He seemed to speak through his long nose.
"I wanted to get myself established first," I replied. "Seeing as the equipment was all there ...And as I'm sure you know, Sir Peter has given me some other duties, too."
He blinked through the spectacles. "Other duties, eh? How about that? Yes, the director did say you had a special project you were working on for him." He turned to the two Waafs. "A special project. How about that, girls?"
"Allow me to introduce Gwen Liss and Joan Lamb," said Whybrow, pointing at each in turn. "I say, he should have come here first of all, shouldn't he, girls?"
I ignored him. One of the women giggled. It was Gwen, the thin brown-haired one, whose cheeks were rather drawn in. This gave her a look of passionate austerity. Joan, meanwhile, was fair and broad, Germanic or Scandinavian in appearance if one had to put a label on it, but with dark eyes. With her blonde hair and freckles, the combination was also rather striking.
Whybrow waved a dismissive hand at the Waafs. "Give us a minute, will you." He gestured peremptorily at the red balloons on the ceiling. "Send up one of those and get me a cloud height estimation."
Without saying a word, Joan tugged on one of the strings, Gwen seizing the balloon as it came down. It more or less filled the doorway as she took it out, holding it before her as if she were a waitress with a tray. Joan followed.
Once they had left, Whybrow turned to me, folding his hands on his RAF tunic with the air of someone about to make a speech. "I don't quite understand why a Type 3 outstation need be set up in Wallace Ryman's garden, but who am I to reason why? Apparently you are a 'bright young thing' who needs careful handling. A real scientist, Sir Peter said, as if the rest of us aren't. Well, young man, I'll be expecting the very best from you, as from any other observer."
"Of course, sir," I said, putting a deliberate meekness into my voice. Whybrow was more or less irrelevant so far as my true task was concerned, but there was no point in antagonising him for the sake of it. And there could, after all, I thought then, be some way in which I might need his help.
"Right, then. Let's get down to brass tacks. Have you sent up any sondes yet?"
"I haven't any hydrogen."
"We sent over all the requisites."
"I have never made it before. The tanks came ready supplied at Kew."
He laughed abruptly, as if pleased to discover I wasn't such a knowit-all after all. "Then you had better come with me."
Leaving the farmhouse, we walked through the mud that divided the Nissen huts, all of which were of uniform height. The hydrogen shed was much bigger. From a kind of gable at one end of it, the tower of the cloud searchlight rose, giving the whole complex the air of a makeshift airfield.
"Gwen! Joan!" shouted Whybrow.
He called again. A red balloon appeared from behind one of the huts. Eventually the balloon entered the cloud.
"Three hundred and ten feet, sir," said Joan emerging from the hut, followed shortly afterwards by Gwen.
They both, I would later learn, came from landed families in Norfolk. The sort of stylish women to whom everything came easily, they seemed odd candidates to be stuck up in this backwater. But then, war did that to all of us, moving us around its chessboard in ways we never expected.
"Jolly good," said Whybrow nasally. "Now, I'd like you, one or other of you, or both, to show our new arrival how to make hydrogen. Then send him to Mr. Pyke up at Loch Eck."
He turned to me. "Sir Peter said I was to introduce you to someone from Combined Ops' Experimental Section who is up here. Strange fellow, Pyke. Very hot to use science for war, and clever with it. Anyway, good luck!"
On this oddly cheery note, Whybrow made his way back to the Ops Room, his square back framed in the rectangle of light between two Nissen huts. Without saying anything to me, the two women began walking in the direction of the tall hydrogen shed.
Falling into pace behind them, I couldn't help noticing their fine shoes were covered in mud. They were court shoes, but fine ones, not the standard, pump-like things that most of the Waafs wore, which looked like comical black frogs.
"Shame to cover such nice shoes in mud," I said to their backs. "They look rather expensive. You ought to be in wellies, with this lot."
"Not likely," said Joan over her shoulder. "We wouldn't be seen dead in wellies." It struck me as odd that she should speak for them both.
"Hydrogen shed," Gwen announced bluntly. They both spoke in this clipped, staccato manner. She pushed against the door and I followed them inside.
The lights flickered on to reveal a large warehouse-like space. At one end were some stairs leading up to the gable, out of which a mezzanine floor projected. There was a balcony there with something vertical behind, just showing in the darkness above the lights: a suspended row of aluminium-shaded lamps, looking like soldiers' helmets hanging from wires. The floor space below, empty in the centre, was lined with steel drums of caustic soda and piles of cylinders for storing hydrogen.
"This is the generator," said Joan. She indicated another drum, smaller and thicker than those in which the caustic soda was stored. It was sealed with a screw-down lid, out of which projected a black rubber tube.
I stubbed my toe on something and swore. The women laughed maliciously. I peered down to see what had injured me: a lozenge of lead. "That's the safety weight," explained Gwen, her tone kinder than before. "We're always doing that. We have a whale of a time doing that."
She pulled on some rubber gloves and fetched a lump of caustic soda, holding it up to the light as she walked back towards me. It looked like a cake of salt. "You don't want to get this horrid stuff on your skin." She put it in the generator, along with some water. "Fill to two-thirds."
"Add a cupful of iron filings," said Joan, leaning over.
"Ferrosilicon, really," said Gwen, watching Joan pour the catalyst into the cylinder. Then, as Gwen moved quickly to screw down the lid, Joan picked up the lead weight next to my foot. She placed it on the rubber tube where it emerged from the lid. Steadying herself by putting out a hand to Gwen's shoulder, Joan stood on the weight, first with one foot, then the other.
"You have to do this or the weight can come off," she said, as the reaction began. Balancing, arms outstretched, she looked like an outsize Christmas fairy. Next to her, inside the cylinder, the recipe for hydrogen fizzed and gurgled.
The reaction came to a peak. Gwen produced an empty balloon from her tunic, knelt down beside the canister and began rolling the nozzle over the stubby tube. "You have to thread it on quite carefully," she said.
"Or it can all go wrong," added Joan from her pedestal.
I watched the balloon begin to inflate.
"Hydrogen," said Gwen, holding the sides of the balloon with her palms as it filled up. "Lightest element in the universe, ta-ra ta-ra."
"And the most abundant," said Joan, stepping down from the lozenge as the reaction came to equilibrium. "Fifteen pounds of it in every human body." They sounded like music-hall comedians, limbering up for a punchline.
Gwen unrolled the nozzle of the balloon from its umbilical tube, knotted it and let go. It danced up past the row of lights, rising to the apex of the ceiling.
"How will you get it down?" I wondered aloud, watching.
"We'll show you," said Joan. "Come on."
I stood in the centre of the shed. "Isn't it highly explosive? It could burn on those lights."
"Only if there's a spark," said Gwen. "Come along."
I followed them across the cavernous shed and up some narrow stairs that led to the gable end and the balcony. Climbing up through an open trapdoor, I saw there were several steel sheets bolted to the wooden floor as foundations for some kind of structure. It was quite dark up there, but I made out the base of the cloud searchlight tower. Beneath it were two thin mattresses side by side, with pillows and blankets. I was surprised, my mind raced . . . they surely hadn't brought me into a bedroom?
"We sometimes take turns to have a nap up here while on duty," Gwen said, by way of explanation. She turned on a little lamp: just a bare bulb fixed to one of the wooden rafters.
In the new light I saw two little bowls of make-up on the floor and a full-length mirror draped with clothing. Under the mirror was a small pile of shoes. There was also an easel and a stack of canvases, together with a palette covered with hardened oil paint of various hues, jam jars full of paintbrushes, and a wooden tray of half-squeezed tubes of paint.
"We paint up here too," said Gwen. "We're artists, you see."
Even more surprised, I looked at the picture on the easel. It showed a long yellow beach with rolling breakers curved along a bay. Among puddles of seawater in the sand, a couple of black dogs jumped about, chasing salt-wet tails. The dogs' tails and the curling breakers mirrored each other, as if the intention was to convey a relationship between them. Behind the dogs, blues and yellows and greens of varying relationships blended into the glow of the horizon.
"That's pretty good," I said, aware of them looking at me in expectation of an opinion.
"Not good enough," said thin Gwen, and I wondered for a second if she was referring to my response rather than the painting itself.
"Never is," said Joan. "Would you like some tea?"
"Oh, yes please," I replied. "Which of you did it?"
"We do them together," Gwen said proudly.
"That's unusual."
"Maybe. It's our thing. We hope to apply to the Slade, if this horrid war ever ends."
"What do you think we should call it?" Joan asked me.
I looked again at the painting. "Dogs in Foam?"I ventured,and they both laughed, hooting loudly.
On a low table next to the mirror was everything needed for brewing tea. Joan put a small kettle on. The three of us stood slightly awkwardly, waiting for it to boil.
"What does Whybrow think?" I asked.
"What about?" said Gwen.
"You two having this little den."
"Oh, he doesn't mind," said Joan, pouring hot water into a teapot.
"He daren't," Gwen said. "We think he's scared of us."
"He says we make him anxious," said Joan, pouring, then handing me a mug.
Neither replied. As we drank our tea, I studied the metal-grid pylon-like tower which rose out of the floor towards the roof, where—bolted on either side of the pitch—there were two more trapdoors. The glass of the searchlight and some meteorological gauges were suspended on a trackway in the middle of the grid, which was raised by a geared winding system.
"Can I see it work?" I asked.
"It's not worth turning on in the day," said Gwen. "And at night it attracts bombers, but basically we undo these..." She climbed onto the grid of the tower and unbolted one of the trapdoors, which fell down with a bang. Cold air rushed down. I could see the sky—and Gwen's calves.
All in a pickle, I quickly looked down again, trying not to catch the eye of Joan, who was standing next to me. I didn't quite succeed. I was sure she was smirking. The suspicion began to grow in me that the whole thing had been done for my benefit. Or theirs. Had I been had? I was beginning to see how Whybrow might find them perturbing. They seemed to be the kind of women who could turn men round their little fingers, and enjoy the sport of doing it.
There was another bang as Gwen let down the second trapdoor.
Joan grasped a metal handle and began winding the worm gear which raised the tower. It ascended like a theatrical device. I watched as Gwen rose further with the tower until her head poked out of the roof. Her silk-stockinged ankles were now level with my face. I felt overcome by simple lust.
"Jeepers, it's nippy up here," she called.
I stared. There was something hypnotic about the way—like a graph curve, like a continuous function—the material followed the flow of skin and bone.
Things were made worse by Joan's hand brushing my back as she reached for the handle of the worm gear. "You could help," she said, starting to wind. "This thing hurts my wrist."
So I wound the tower—and Gwen—down again. Joan was right. It was quite hard, in spite of the gear.
"In summer," said Joan, "we can smell jasmine up there on the wind."
"Very romantic," I said.
"Whereas in winter we get chilblains," said Gwen crisply, climbing down beside us. "Joany, we'd better get that balloon."
I looked over the balcony to the balloon on the ceiling. The suspended lights shone a peculiar red through the rubber, like torchlight through fingers. Gwen appeared, holding a pole with a hook on the end—like a boat gaffe—and Joan leaned out over the balcony to deftly hook the balloon.
"Yes," said Gwen, as she and I descended to the ground floor. "No, hand it down. I'll do it."
She took the other end of the pole from Joan, who then climbed down herself.
Gwen opened the door of the shed to let the gas out of the balloon, sounding a long, slow exhalation. I imagined the molecules of hydrogen spreading out into the atmosphere and combining with other elements.
"Whybrow mentioned seeing Pyke from Combined Ops at Loch ...Loch..." I said, frowning and moving my weight from one foot to another as I tried to remember the name.
"Eck. I'll show you where to drive," said Joan. "It's not far. Pyke is usually on the loch at this time. If he's not there he'll be at the Argyll Hotel in town."
I was pleased it was her. For I have to admit, it was Joan who (in the midst of my ignorance) was stirring my pot then, more than Gwen, despite the business with the stockings. How they will laugh if they ever read this!
We walked through the mud and the old farmyard towards the gate.
"How will I recognise Pyke?" I asked.
I swung my leg over the motorcycle.
"There's no mistaking him," she said. "He has a messy little beard, wears specs. Looks a bit peculiar. Holes in his suit jacket." She giggled. "You better watch out or that's what you will become."
"Why?" I asked, affronted.
"All you scientists end up that way."
"What do you mean?"
"You have no style. All you think about are your equations."
"Ah," I said, rising to the challenge. "But that is just it, don't you see? The style is in the equations. Some people write ugly proofs, others do it with panache. I like to think mine are as beautiful as, as—well, anything!"
I watched her face become aghast. "Anything? Anything is not beautiful. Only special things are beautiful."
I felt embarrassed at my inability to express myself. "All right, Miss, if you say so. But one day I'll show you some of those equations and you will see what I mean."
"I look forward to it."
After giving directions to the quay at Loch Eck, she said goodbye to me, then turned and headed back to the station.
I managed to stall the motorbike after just a few yards.As I was sitting in the middle of the road, kicking the starter, I became aware of a detachment of troops marching towards me. American infantry. It was too late for me to move. They separated on either side of me before rejoining; exercise-hardened faces giving no acknowledgement of my presence.
I sat frozen to the seat. I have never seen a statue of a man on a motorbike but that's what I was, a monument around which they flowed with the molecules of the air. After the rupture, when the men re-formed, it was as if there had been no disturbance. Turning on the saddle to watch the soldiers grow smaller down the road, I thought again about the invasion of which they might become a part, for which I was supposed to help predict the weather by unwrapping the mysteries of the Ryman number.
I kicked the pedal. Under gunfire on a beach...I did not envy them that. I kicked the pedal again.
Starting the engine, finally, I was shaken by a grave doubt as to whether anything I could do as a meteorologist could match what would be asked of those soldiers.
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"Turbulence' is an ambitious and original topic that fictionalises the debates between weather forecasters and strategists that preceded the D-Day Invasion. The slow moving plot starts in the 1980's on an ice ship destined for the Middle East. The melancholic Henry Meadows reminisces and recounts his time spent during the war effort. The story is narrated in the first person by Henry, a young Cambridge academic who was entrusted to develop a method that would allow the military commanders to choose the ultimate timing for the invasion. Sent to Scotland to establish an observation station, his first mission was to befriend and extract information from Wallace Ryman the author of a mathematical formula for calculating turbulence and eventually determine the best dates for the D-day landings. Meadow soon learned that instability and unpredictability are not limited to weather events....... This novel is cleverly written, full of tension, emotions and melancholy throughout. The scientific and mathematical areas are handled with brilliance, it is not an easy feat keeping fiction readers captivated and interested on a subject that is profoundly science based. The degree of accuracy is irrelevant after all it is a fiction. This is also a character driven-plot where friction between intriguing and strong personalities plays an important part and is very well narrated. The story ends with a panorama of the D-Day landings and Henry in the middle of the action....surely an unexpected development for a civilian mathematician... I enjoyed reading this different perspective of a very important time in history


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"The Artist's Daughter" , Nancy Douglas Bowditch, p224
20. Letter to Mrs. Harold Bowditch from Shoghi Effendi via Ruhi Afnan. Dated 19-9-30. The Persian Colony, Haifa, Palestine.
Dear Bahai Sister;
Shoghi Effendi wishes me to acknowledge the receipt of your letter dated August 18th, 1930. He hopes that as chairman of the Assembly you will succeed to render many services to the Cause in Boston. Such offices carry with them great responsibilities, but these are blessings for they enable us to serve the Cause so much more. The primary duty of the Assemblies is to take the initiative and find the ways and means for spreading the Cause and strengthening its position.
Teaching in these days is of paramount importance. Shoghi Effendi hopes that the Boston friends will do their best to provide nice meetings where the public is attracted and then encourage personal contact with those who are interested.
The Cause needs new blood, it needs more and more new adepts, new and competent servants. If we do not achieve that we will soon discover ourselves a secluded dying institution. A group can either progress or die, it can never linger idle and survive. Shoghi Effendi will remember the members of the Boston Assembly in his prayers and ask for them divine guidance and help.
Yours ever sincerely,
Ruhi Afnan.
Note in Shoghi Effendi s handwriting:
Assuring you of my fervent prayers for your success and spiritual advancement.
Your true brother,


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Tim Meyer has been a guest on 2 episodes.
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July 22nd, 2016 | 1 hr 49 mins
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On Brexit, with Tim Meyer.
Episode 2: Bust a Deal, Face the Wheel
January 4th, 2014 | 1 hr 8 mins
climate change, coffee, international law
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