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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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Comparative pathology of animals continuously exposed to varied concentrations of carbon tetrachloride vapor in altitude chamber
Intestinal absorption of radioiodide in rats exposed to hypoxia and food deprivation
Space suit atmosphere physiological suitability for prolonged moderate work, studying blood-gas parameter changes
Altitude hypoxia as stimulant of new blood vessel formation /angiogenesis/ and wound healing in mice
Thermal contact resistance measurement at various ambient pressures compared with theoretical predictions with each parameter analyzed over interface by computer program
Inspired carbon dioxide pressure effects on human response to physical exercise, noting dyspnea and intercostal muscle pain
Prolonged hyperoxia effects on lipid synthesis in rat liver and adipose tissue slices
Electronic to vibrational energy transfer in mercury vapor reaction with hydrogen fluoride, studying IR emission and scattering cross section
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A crossed charged beam technique was employed in the investigation reported. The ion beam was crossed at right angles by a magnetically confined electron beam. Cross sections were determined as a function of electron impact energy. Considerable structure in the excitation cross section appears immediately above the threshold. It is pointed out that a primary application of cross sections is related to the calculation of plasma rate coefficients.
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Sputtering and deposition rates were measured for discharge chamber components of a 30-cm diameter mercury ion thruster. It was found that sputtering rates of the screen grid and cathode baffle were strongly affected by geometry of the baffle holder. Sputtering rates of the baffle and screen grid were reduced to 80 and 125 A/hr, respectively, by combination of appropriate geometry and materials selections. Sputtering rates such as these are commensurate with thruster lifetimes of 15,000 hours or more. A semiempirical sputtering model showed good agreement with the measured values.
A 9 channel demonstration of 10 micrometer photoconductive mercury cadmium telluride detector array, bipolar preamplifiers, and a Si CCD multiplexer, integrated into a focal plane assembly and operating at 105 K and at 17 Hz is reported. The result of a direct coupling experiment between a 5-micrometer photovoltaic mercury cadmium telluride photodiode and a CCD is revealed. No appreciable degradation in the signal-to-noise ratio was experienced.
Sputtering and deposition rates have been measured for discharge chamber components of a 30-cm diameter mercury ion thruster. It was found that sputtering rates of the screen grid and cathode baffle were strongly affected by geometry of the baffle holder. Sputtering rates of the baffle and screen grid were reduced to 80 and 125 A/hr, respectively, by combination of appropriate geometry and materials selections. Sputtering rates such as these are commensurate with thruster lifetimes of 15,000 hours or more. A semiempirical sputtering model showed good agreement with the measured values.
A double discharge technique was used in the investigation. An initial discharge established between parallel arrays of tungsten pin electrodes was followed, after a variable time delay, by a high voltage (180 kV), short duration (50 nsec) secondary discharge between two aluminum main electrodes. Metal compounds, including metal alkyls, hydrides, and halides, were used to obtain the required metal atom concentrations. Twenty-four new laser transitions involving 9 different metal atoms were observed. The observed relations are shown in a number of partial energy-level diagrams.
Multilayered mercury-cadmium telluride photoconductive detectors were developed which are capable of providing individual coverage of three separate spectral wavelength bands without the use of beam splitters. The multilayered "three-color" detector on a single dewar takes the place of three separate detector/filter/dewar units and enables simpler and more reliable mechanical and optical designs for multispectral scanners and radiometers. Wavelength channel design goals (in micrometers) were: 10.1 to 11.0, 11.0 to 12.0, and 13.0. Detectivity for all channels was 1 x 10 to the 10th power cm-Hz 1/2/Watt. A problem occurred in finding an epoxy layer which had good infrared transmission properties and which also was chemically and mechanically compatible with HgCdTe processing techniques. Data on 6 candidate bonding materials are surveyed and discussed.