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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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User-oriented conversational language computer program for Jet Propulsion Laboratory digital control random excitation environmental test system for spacecraft
Benzene, benzene-d sub 6 and sulfur dioxide radiative lifetime measurement comparison, investigating internal conversion behavior
Stiffened horizontal stoppable hingeless rotor conversion from helicopter to airplane flight speeds
Startup testing of SNAP 8 power conversion system coupled with nuclear reactor simulator
Color conversion model of equivalences under various illuminants, reducing problem to chromatic adaptation with nonlinear von Kries formulation
Rankine cycle turboelectric nuclear space power conversion system with liquid K as working fluid, discussing current technology status
Automated endurance testing of 2-15 kWe Brayton power conversion system, using rotating unit, heat exchanger, electronic voltage regulator, parasitic speed control
Brayton cycle power conversion system using He-Xe gas mixture, discussing compressor net engine and turbine static efficiencies
Electrical subsystem of 2-15 kW Brayton power conversion system consisting of speed controller, alternator voltage regulator, DC power supply, etc
Solar wind velocity increase by magnetic field energy conversion to kinetic energy, constructing steady state MHD one fluid model
Mathematical model for solar flares formation based on magnetic/kinetic energy conversion, investigating plasma instability
The Brayton rotating unit (BRU), consisting of a turbine, an alternator, and a compressor, was tested as part of a Brayton cycle power conversion system over a side range of steady state operating conditions. The working fluid in the system was a mixture of helium-xenon gases. Turbine inlet temperature was varied from 1200 to 1600 F, compressor inlet temperature from 60 to 120 F, compressor discharge pressure from 20 to 45 psia, rotative speed from 32 400 to 39 600 rpm, and alternator liquid-coolant flow rate from 0.01 to 0.27 pound per second. Test results indicated that the BRU internal temperatures were highly sensitive to alternator coolant flow below the design value of 0.12 pound per second but much less so at higher values. The armature winding temperature was not influenced significantly by turbine inlet temperature, but was sensitive, up to 20 F per kVA alternator output, to varying alternator output. When only the rotational speed was changed (+ or - 10% of rated value), the BRU internal temperatures varied directly with the speed.
Zero- and third-order digital-to-analog conversion techniques are described, and the theoretical error performances are compared. The design equations and procedures for constructing a third-order digital-to-analog converter by using analog design elements are presented. Both a zero- and a third-order digital-to-analog converter were built, and the performances are compared with various signal inputs.
Performance characteristics of electrical subsystem for 2 to 15 kilowatt Brayton power conversion system
A system has been developed which permits the determination of dose in real time or near real time directly from the pulse-height output of a radiation spectrometer. The technique involves the use of the resolution matrix of a spectrometer, the radiation energy-to-dose conversion function, and the geometrical factors, although the order of matrix operations is reversed. The new technique yields a result which is mathematically identical to the standard method while requiring no matrix manipulations or resolution matrix storage in the remote computer. It utilizes only a single function for each type dose required and each geometric factor involved.
A system is presented which will reduce analog cardiac performance data and convert the results to digital form for direct entry into a commercial time-shared computer. Circuits are discussed which perform the measurement and digital conversion of instantaneous systolic and diastolic parameters from the analog blood pressure waveform. Digital averaging over a selected number of heart cycles is performed on these measurements, as well as those of flow and heart rate. The determination of average cardiac output and peripheral resistance, including trends, is the end result after processing by digital computer.
Detailed analysis of an analog-to-digital conversion system consisting of a linear converter and a logarithmic amplifier containing nonlinear elements. It is shown that the small-signal resolution of such a system is much greater than that of linear systems used under the same conditions. A design for a low-power analog-to-digital converter operating at medium speed with a large input signal variation field is outlined.
Description of a one-stage approximation to the color-conversion model of Richards and Parks (1971). The modified model proposes three channels for color vision, each with different center-surround sensitivities. In its strongest form, the model predicts that the gain-setting control that alters the sensitivities of each channel is solely a function of achromatic contrast.