1,670 research outputs found

    Development, testing and certification of the sigma research, maxi-therm-S-101 thermosyphon heat exchanger

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    A thermosyphon liquid-to-air heat exchanger developed for use in heating systems in residential single family dwellings and small commercial applications is described. The cabinet design, rationale for the horizontal positioning of the exchanger, and design of the shut-off valve are discussed. The performance of the heating module is given in tabular form

    High speed machining of space shuttle external tank liquid hydrogen barrel panel

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    Actual and projected optimum High Speed Machining data for producing shuttle external tank liquid hydrogen barrel panels of aluminum alloy 2219-T87 are reported. The data included various machining parameters; e.g., spindle speeds, cutting speed, table feed, chip load, metal removal rate, horsepower, cutting efficiency, cutter wear (lack of) and chip removal methods

    Temperature rise of flat conductor cable installed under carpet

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    The method, test data, and results of temperature rise tests are reported on flat conductor cable installed under carpet and powered at up to twice rated loads

    Development and testing of the Rho Sigma Incorporated microprocessor control subsystem

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    Product development and performance tests of three programmable microprocessor controllers for use with solar heating and cooling systems are presented. The products were developed to be marketable for public use

    Testing of a flat conductor cable baseboard system for residential and commercial wiring

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    The results of extensive testing (mechanical, electrical, chemical, environmental, thermal, and analytical) are reported for a flat conductor cable baseboard system for residential and commercial wiring. In all of the tests, Underwriters Laboratories (UL) Standards, UL Tentative Test Programs, or Accepted Engineering Practices were followed during test selection, test setup, and test accomplishment

    Development and testing of the Solar Control Corporation modular controller and Solarstat subsystem

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    Results of development work on an existing controller and solarstat subsystem for use with solar heating and cooling systems are presented. The deliverable end items, program objectives, and how they were accomplished are described. It is shown that the products developed are marketable and suitable for public use

    Flat conductor cable handbook

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    Handbook includes discussion of FCC advantages, status of FCC regarding military specifications, hardware availability, and existing applications, descriptions and data on available cable, connectors, fasteners and hardware, design techniques and applications, wiring, manufacturing and installation techniques - and inspection and test procedures

    Multifrequency Observations of Giant Radio Pulses from the Millisecond Pulsar B1937+21

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    Giant pulses are short, intense outbursts of radio emission with a power-law intensity distribution that have been observed from the Crab Pulsar and PSR B1937+21. We have undertaken a systematic study of giant pulses from PSR B1937+21 using the Arecibo telescope at 430, 1420, and 2380 MHz. At 430 MHz, interstellar scattering broadens giant pulses to durations of 50μ\sim50 \musecs, but at higher frequencies the pulses are very short, typically lasting only 1\sim1-2μ2 \musecs. At each frequency, giant pulses are emitted only in narrow (\lsim10 \mus) windows of pulse phase located 55\sim 55-70μ70 \musec after the main and interpulse peaks. Although some pulse-to-pulse jitter in arrival times is observed, the mean arrival phase appears stable; a timing analysis of the giant pulses yields precision competitive with the best average profile timing studies. We have measured the intensity distribution of the giant pulses, confirming a roughly power-law distribution with approximate index of -1.8, contributing \gsim0.1% to the total flux at each frequency. We also find that the intensity of giant pulses falls off with a slightly steeper power of frequency than the ordinary radio emission.Comment: 21 pages, 10 Postscript figures; LaTeX with aaspp4.sty and epsf.tex; submitted to Ap

    Operational experience and design recommendations for teleoperated flight hardware

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    Teleoperation (remote manipulation) will someday supplement/minimize astronaut extravehicular activity in space to perform such tasks as satellite servicing and repair, and space station construction and servicing. This technology is being investigated by NASA with teleoperation of two space-related tasks having been demonstrated at the Oak Ridge National Lab. The teleoperator experiments are discussed and the results of these experiments are summarized. The related equipment design recommendations are also presented. In addition, a general discussion of equipment design for teleoperation is also presented
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