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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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Studying vaporization of indium-gallium oxide, and gallium-aluminum oxide by Knudsen effusion mass spectroscopy
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Using vacuum-soldering method, attachments that are 85 to 95 percent void free can be made. Method is useful for various large scale substrate attachment processes in microelectronic industry.
Metallography from experiment 24-10 obtained on the second space processing applications rocket (SPAR) flight is discussed. Results are considered along with results from the related experiments on the first SPAR flight. Conclusions are presented.
Prominent bands in the spectral profiles of Fe-Ti phases in lunar samples have been attributed to charge-transfer transitions between Fe and Ti cations, and a model is presented for calculating charge transfer energies from energy levels computed by the SCF-X(alpha) scattered wave molecular orbital method for isolated MO6 octahedral coordination clusters containing Fe(2+), Fe(3+), Ti(3+), and Ti(4+) cations. The calculated charge transfer energy for the Fe(2+) to Ti(4+) transition correlates well with a measured spectral feature around 0.6 micron in ilmenite, and, since ilmenite is a major constituent of mare basalts and dark-mantling material, the observed darkness and blueness of the regolith in lunar black spots is attributed primarily to this transition. The Ti(3+) to Ti(4+) transition is thought to contribute to some phases.
Materials including copper powders, silver-fluoride, and silicon wafers were procured and copper pastes were prepared. Electrodes made with copper pastes were analyzed and compared with the raw materials. A needle-like structure was observed on the electroded solar cells, and was identified as eutectic copper-silicon by electron probe X-ray spectroscopy. The existence of this phase was thought to benefit electrical and metallurgical properties of the contact. Subsequently electrodes made from new material were also shown to contain this phase while simultaneously having poor adhesion.
Screened electrodes made from fluorocarbon activated copper paste and silver fluoride activated copper paste, tape adhesion and scratch tests were studied. Experiments were conducted with variations in past parameters, firing conditions, including gas ambients, furnace furniture, silicon surface and others. A liquid medium intended to provide transport during the carbon fluoride decomposition, is incorporated in the paste.
(Previously announced in STAR as N81-28233)
Electrodes made with pastes produced under the previous contract were analyzed and compared with raw materials. A needle-like structure observed on the electroded solar cell was identified as eutectic copper-silicon, a phase considered to benefit the electrical and metallurgical properties of the contact. Electrodes made from copper fluorocarbon and copper silver fluoride also contained this phase but had poor adhesion. A liquid medium, intended to provide transport during carbon fluoride decomposition was incorporated into the paste resulting in better adhesion. The product survived preliminary environmental tests. A 2 cm by 2 cm solar cell made with fluorocarbon activated copper electrodes and gave 7% AMI efficiency (without AR coating). Both silver fluoride and fluorocarbon screened paste electrodes can be produced for approximately $0.04 per watt.
The chemical mechanisms for sulfate formation from sodium chloride and sulfur trioxide, which is a product of jet fuel combustion was determined. Molten sodium sulfate leads to hot corrosion of the protective oxide layers on turbine blades. How yttrium dopants in nidkel-aluminum alloys used in turbine blades reduce the spalling rate of protective alumina films and enhance their adhesion was also determined. Two other fulfate mechanisms were deduced and structure of carbon monoxide on a clean chronium and clean platinum-titanium alloys surfaces was determined. All studies were by use of the atom superposition and electron delocalization molecular orbital (ASED-MO) theory. Seven studies were completed. Their titles and abstracts are given.
A survey of methods and equipment used in the riveting of German aircraft. Includes descriptions and illustrations.
The sizing and efficiency of an aircraft is largely determined by the performance of its high-lift system. Subsonic civil transports most often use deployable multi-element airfoils to achieve the maximum-lift requirements for landing, as well as the high lift-to-drag ratios for take-off. However, these systems produce very complex flow fields which are not fully understood by the scientific community. In order to compete in today's market place, aircraft manufacturers will have to design better high-lift systems. Therefore, a more thorough understanding of the flows associated with these systems is desired. Flight and wind-tunnel experiments have been conducted on NASA Langley's B737-100 research aircraft to obtain detailed full-scale flow measurements on a multi-element high-lift system at various flight conditions. As part of this effort, computational aerodynamic tools are being used to provide preliminary flow-field information for instrumentation development, and to provide additional insight during the data analysis and interpretation process. The purpose of this paper is to demonstrate the ability and usefulness of a three-dimensional low-order potentialflow solver, PMARC, by comparing computational results with data obtained from 1/8 scale wind-tunnel tests. Overall, correlation of experimental and computational data reveals that the panel method is able to predict reasonably well the pressures of the aircraft's multi-element wing at several spanwise stations. PMARC's versatility and usefulness is also demonstrated by accurately predicting inviscid threedimensional flow features for several intricate geometrical regions.