743 research outputs found

    Evaluation of commercially-available spacecraft-type heat pipes

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    As part of an effort to develop reliable, cost effective spacecraft thermal control heat pipes, life tests on 30 commercially available heat pipes in 10 groups of different design and material combinations were conducted. Results for seven groups were reported herein. Materials are aluminum and stainless steel, and working fluids are methanol and ammonia. The formation of noncondensible gas was observed for times exceeding 11,000 hours. The heat transport capacities of the pipes were also determined

    Accelerated life tests of specimen heat pipe from Communication Technology Satellite (CTS) project

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    A gas-loaded variable conductance heat pipe of stainless steel with methanol working fluid identical to one now on the CTS satellite was life tested in the laboratory at accelerated conditions for 14 200 hours, equivalent to about 70 000 hours at flight conditions. The noncondensible gas inventory increased about 20 percent over the original charge. The observed gas increase is estimated to increase operating temperature by about 2.2 C, insufficient to harm the electronic gear cooled by the heat pipes in the satellite. Tests of maximum heat input against evaporator elevation agree well with the manufacturer's predictions

    The production and marketing of North Carolina furniture

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    Thesis (M.B.A.)--Boston Universit

    Radiometric infrared focal plane array imaging system for thermographic applications

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    This document describes research performed under the Radiometric Infrared Focal Plane Array Imaging System for Thermographic Applications contract. This research investigated the feasibility of using platinum silicide (PtSi) Schottky-barrier infrared focal plane arrays (IR FPAs) for NASA Langley's specific radiometric thermal imaging requirements. The initial goal of this design was to develop a high spatial resolution radiometer with an NETD of 1 percent of the temperature reading over the range of 0 to 250 C. The proposed camera design developed during this study and described in this report provides: (1) high spatial resolution (full-TV resolution); (2) high thermal dynamic range (0 to 250 C); (3) the ability to image rapid, large thermal transients utilizing electronic exposure control (commandable dynamic range of 2,500,000:1 with exposure control latency of 33 ms); (4) high uniformity (0.5 percent nonuniformity after correction); and (5) high thermal resolution (0.1 C at 25 C background and 0.5 C at 250 C background)

    Sleep‐disordered breathing and poststroke outcomes

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150527/1/ana25515_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150527/2/ana25515.pd

    Interest and barriers to research in obstetric haematology – findings from a national survey in the United Kingdom

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    Introduction: In 2021, the steering committee members of British Society of Haematology Obstetric Haematology Special Interest Group noted difficulties in opening research studies. This led to the development of a survey to further evaluate this issue. Method: An electronic survey was distributed to all members of the British Society of Haematology Obstetric Haematology Special Interest Group and to relevant specialty leads of the National Institute for Health and Care Research Clinical Research Network for further dissemination within these networks. Results: Responses were received from 65 participants (73% consultant grade); mainly haematologists (52%) or obstetricians (39%). Less than a third of participants reported dedicated time for research in their job plan, with only five participants reporting no challenges in opening research studies in obstetric haematology. Discussion: The survey confirmed significant interest in obstetric haematology research, with barriers to participation. We propose further actions to facilitate increased research
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