5,721 research outputs found

    Evaluation of commercial pyroelectric detectors

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    A series of commercially available pyroelectric detectors made from PVF2, LTO, SBN, and TGS were evaluated in terms of responsivity and detectivity as a function of frequency. The performance of the detectors evaluated was very different, depending upon the manufacturer of the detector, and this dependency was primarily related to the thickness of the various detectors. The best detectors of each material were comparable in performance at frequencies around 10 Hz but differed radically at frequencies above 100 Hz

    Improved test methods for determining lightning-induced voltages in aircraft

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    A lumped parameter transmission line with a surge impedance matching that of the aircraft and its return lines was evaluated as a replacement for earlier current generators. Various test circuit parameters were evaluated using a 1/10 scale relative geometric model. Induced voltage response was evaluated by taking measurements on the NASA-Dryden Digital Fly by Wire F-8 aircraft. Return conductor arrangements as well as other circuit changes were also evaluated, with all induced voltage measurements being made on the same circuit for comparison purposes. The lumped parameter transmission line generates a concave front current wave with the peak di/dt near the peak of the current wave which is more representative of lightning. However, the induced voltage measurements when scaled by appropriate scale factors (peak current or di/dt) resulting from both techniques yield comparable results

    Editorial

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    An introduction to this re-launch edition of the journal by the new members of the editorial tea

    Reusable thermal cycling clamp

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    A reusable metal clamp for retaining a fused quartz ampoule during temperature cycling in the range of 20 deg C to 1000 deg C is described. A compressible graphite foil having a high radial coefficient of thermal expansion is interposed between the fused quartz ampoule and metal clamp to maintain a snug fit between these components at all temperature levels in the cycle

    New microsatellite markers for pigeonpea (cajanus cajan (L.) millsp.)

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    <p>Abstract</p> <p>Background</p> <p>Pigeonpea is a nutritious tropical legume with several desirable characteristics but has been relatively neglected in terms of research. More efficient improvement can be achieved in this crop through molecular breeding but adequate molecular markers are lacking and no linkage map has been developed so far. Microsatellites remain the markers of choice due to their high polymorphism and their transferability from closely related genera. The overall objective of this study was to develop microsatellite markers from an enriched library of pigeonpea as well as testing the transferability of soybean microsatellites in pigeonpea.</p> <p>Results</p> <p>Primers were designed for 113 pigeonpea genomic SSRs, 73 of which amplified interpretable bands. Thirty-five of the primers revealed polymorphism among 24 pigeonpea breeding lines. The number of alleles detected ranged from 2 to 6 with a total of 110 alleles and an average of 3.1 alleles per locus. GT/CA and GAA class of repeats were the most abundant di-nucleotide and tri-nucleotide repeats respectively. Additionally, 220 soybean primers were tested in pigeonpea, 39 of which amplified interpretable bands.</p> <p>Conclusion</p> <p>Despite the observed morphological diversity, there is little genetic diversity within cultivated pigeonpea as revealed by the developed microsatellites. Although some of the tested soybean microsatellites may be transferable to pigeonpea, lack of useful polymorphism may hinder their full use. A robust set of markers will still have to be developed for pigeonpea genome if molecular breeding is to be achieved.</p

    Development of a long life thermal cell Final report

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    Development of long life thermal cells, environmental and electrochemical performance tests to evaluate their capability and reproductibilit

    Predicting Success In Nursing Programs

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    The purpose of this study was to assess the merit of the Watson -Glaser Critical Thinking Appraisal as a pre-admission criterion in conjunction with the frequently utilized admission criteria of the college prerequisite grade point average and the National League of Nursing pre-admission test. Data were collected from 192 first-year nursing students.  A discriminant analysis was computed to determine the significance of the prediction formula. The predictor variables of prerequisite grade point average, National League for Nursing pre-admission test score, and the Watson-Glaser Critical Thinking Appraisal score were significant in predicting success in a nursing program as measured by the dependent variable nursing grade point average. The prediction formula, as a whole, had a significance level of p &lt; .001. The identification and validation of applicant selection criteria that predict success in the nursing programs will continue to be of significant importance because of emphasis on the importance of fostering critical thinking in nursing education (National League for Nursing Accrediting Commission, Inc., 2012)

    Picture Day

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    From: J. Boyd Crouch

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