8,528 research outputs found

    Photovoltaic system test facility electromagnetic interference measurements

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    Field strength measurements on a single row of panels indicates that the operational mode of the array as configured presents no radiated EMI problems. Only one relatively significant frequency band near 200 kHz showed any degree of intensity (9 muV/m including a background level of 5 muV/m). The level was measured very near the array (at 20 ft distance) while Federal Communications Commission (FCC) regulations limit spurious emissions to 15 muV/m at 1,000 ft. No field strength readings could be obtained even at 35 ft distant

    Conceptual design studies for large free-flying solar-reflector spacecraft

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    The 1 km diameter reflecting film surface is supported by a lightweight structure which may be automatically deployed after launch in the Space Shuttle. A twin rotor, control moment gyroscope, with deployable rotors, is included as a primary control actuator. The vehicle has a total specific mass of less than 12 g/sq m including allowances for all required subsystems. The structural elements were sized to accommodate the loads of a typical SOLARES type mission where a swam of these free flying satellites is employed to concentrate sunlight on a number of energy conversion stations on the ground

    Performance of a centrifugal pump running in inverse mode

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    This paper presents the functional characterization of a centrifugal pump used as a turbine. It shows the characteristics of the machine involved at several rotational speeds, comparing the respective flows and heads. In this way, it is possible to observe the influence of the rotational speed on efficiency, as well as obtaining the characteristics at constant head and runaway speed. Also, the forces actuating on the impeller were studied. An uncertainty analysis was made to assess the accuracy of the results. The research results indicate that the turbine characteristics can be predicted to some extent from the pump characteristics, that water flows out of the runner free of swirl flow at the best efficiency point, and that radial stresses are lower than in pump mode

    Optimised patient information materials and recruitment to a study of behavioural activation in older adults : an embedded study within a trial [version 1; peer review: awaiting peer review]

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    YesPrinted participant information about randomised controlled trials is often long, technical and difficult to navigate. Improving information materials is possible through optimisation and user-testing, and may impact on participant understanding and rates of recruitment. Methods: A study within a trial (SWAT) was undertaken within the CASPER trial. Potential CASPER participants were randomised to receive either the standard trial information or revised information that had been optimised through information design and user testing. Results: A total of 11,531 patients were randomised in the SWAT. Rates of recruitment to the CASPER trial were 2.0% in the optimised information group and 1.9% in the standard information group (odds ratio 1.027; 95% CI 0.79 to 1.33; p=0.202). Conclusions: Participant information that had been optimised through information design and user testing did not result in any change to rate of recruitment to the host trial. Registration: ISRCTN ID ISRCTN02202951; registered on 3 June 2009.UK National Institute of Health Research Health Technology Assessment Programme (project number 08/19/04)This article is included in the Studies Within A Trial (SWAT) collection (https://f1000research.com/collections/swat

    Strahlenpharmakologische untersuchungen mit neutronen an eisenhaltigen praparaten im Siemens unterrichtsreaktor SUR 100

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    Die stark eisenhaltigen Praparate Ferrlecit, Kobaltjerrlecit, Ferrojolsan, Ferrojolcamma und Irradian wurden im Siemens Unterrichtsreaktor SUR 100 des Instituts fur Kernenergetikder Universitat Struttgart und der Technischen Universitat, Berlin mit einem NeutronenfluB von ca. 5.l06n/cm2 sec bestrahlt. Es ollte dabei untersucht werden, wie stark eisenhaltige Praparate mit diesem Reaktor aktiviert werden konnen. Es wird festgestellt, daB Eisen praktisch kaum aktiviert wird. Die Ergebnisse zeigen, daB nur das Kobattjerrlecit und das Irradian starker durch Neutrosen aktiviert werden. Die hohere Aktivitat des Kobaltjerrlecit wird auf die darin enthaltenen Elemente Mangan, Kupfer und Kobalt zuruckgefuhrt, die mit thermischen Neutronen gut aktivierbar sind. Die hohere Aktivitat des Irradian geht hauptsachlich auf &#946;-Zerfalle zuruck. Das Phosphorisotop P-32 tragt einen gro&#946;en Anteil dazu bei. De r&#946;-Untergrund des Irradian bei hohen Energien, der mit einer kleinen Halbwertszeitabklingt, ist durch keines der angefuhrten Elemente im Irradian erklarbar. Der Mn-56Peak im Spektrum ist gut erkennbar, durch den &#946;-Untergrund wird er aber zu einer hoheren Energie hin verschoben.</p

    A Broad Search for Counterrotating Gas and Stars: Evidence for Mergers and Accretion

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    We measure the frequency of bulk gas-stellar counterrotation in a sample of 67 galaxies drawn from the Nearby Field Galaxy Survey, a broadly representative survey of the local galaxy population down to M_B-15. We detect 4 counterrotators among 17 E/S0's with extended gas emission (24% +8 -6). In contrast, we find no clear examples of bulk counterrotation among 38 Sa-Sbc spirals, although one Sa does show peculiar gas kinematics. This result implies that, at 95% confidence, no more than 8% of Sa-Sbc spirals are bulk counterrotators. Among types Sc and later, we identify only one possible counterrotator, a Magellanic irregular. We use these results together with the physical properties of the counterrotators to constrain possible origins for this phenomenon.Comment: 19 pages, 4 figures, AJ, accepte

    Parameters for Twisted Representations

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    The study of Hermitian forms on a real reductive group GG gives rise, in the unequal rank case, to a new class of Kazhdan-Lusztig-Vogan polynomials. These are associated with an outer automorphism δ\delta of GG, and are related to representations of the extended group . These polynomials were defined geometrically by Lusztig and Vogan in "Quasisplit Hecke Algebras and Symmetric Spaces", Duke Math. J. 163 (2014), 983--1034. In order to use their results to compute the polynomials, one needs to describe explicitly the extension of representations to the extended group. This paper analyzes these extensions, and thereby gives a complete algorithm for computing the polynomials. This algorithm is being implemented in the Atlas of Lie Groups and Representations software

    Do Patients Use a Headline Section in a Leaflet to Find Key Information About Their Medicines? Findings From a User-Test Study

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    Background: In the European Union (EU), all medicines are mandated to be provided with a patient information leaflet (PIL). Many patients express concerns about the length and complexity of some PILs, and this can be a disincentive for patients to read the PILS. In order to address this, the UK’s regulatory body (Medicine and Healthcare products Regulatory Agency [MHRA]) suggested leaflets might include a headline section—information presented prominently at the beginning of a leaflet that summarizes key safety messages about a drug. Objective: To explore the extent to which readers used a headline section in a PIL, using a form of diagnostic testing called user-testing, which examines how readers find and understand key information. Methods: The study used a cross-sectional design to user-test a PIL with a headline section in a target sample of 20 participants. Participants were provided with an exemplar PIL, and the performance of the PIL was evaluated by a questionnaire and semistructured interview. Results: The results showed that a headline section was used just over one-third of the time (39%); 90% of participants used the headline section to find information when they initially began the user-test. The qualitative findings suggested that the participants valued the presence of the headline section. Conclusion: The research suggests there does not appear to be any negative impact from including a headline section in a PIL, and it is a technique that is highly valued by the consumers of medicines information

    Systematic techniques for assisting recruitment to trials (START): study protocol for embedded, randomized controlled trials

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    BACKGROUND: Randomized controlled trials play a central role in evidence-based practice, but recruitment of participants, and retention of them once in the trial, is challenging. Moreover, there is a dearth of evidence that research teams can use to inform the development of their recruitment and retention strategies. As with other healthcare initiatives, the fairest test of the effectiveness of a recruitment strategy is a trial comparing alternatives, which for recruitment would mean embedding a recruitment trial within an ongoing host trial. Systematic reviews indicate that such studies are rare. Embedded trials are largely delivered in an ad hoc way, with interventions almost always developed in isolation and tested in the context of a single host trial, limiting their ability to contribute to a body of evidence with regard to a single recruitment intervention and to researchers working in different contexts. METHODS/DESIGN: The Systematic Techniques for Assisting Recruitment to Trials (START) program is funded by the United Kingdom Medical Research Council (MRC) Methodology Research Programme to support the routine adoption of embedded trials to test standardized recruitment interventions across ongoing host trials. To achieve this aim, the program involves three interrelated work packages: (1) methodology - to develop guidelines for the design, analysis and reporting of embedded recruitment studies; (2) interventions - to develop effective and useful recruitment interventions; and (3) implementation - to recruit host trials and test interventions through embedded studies. DISCUSSION: Successful completion of the START program will provide a model for a platform for the wider trials community to use to evaluate recruitment interventions or, potentially, other types of intervention linked to trial conduct. It will also increase the evidence base for two types of recruitment intervention. TRIAL REGISTRATION: The START protocol covers the methodology for embedded trials. Each embedded trial is registered separately or as a substudy of the host trial
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