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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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Quenching distances for flaming thin polymer films, and fire extinguisher using inert gas to reduce fire hazards in spacecraft cabin atmospheres
Rotational inelastic transitions in atom-diatomic collisions, discussing restricted distorted-wave approximation, transition probabilities, impact parameters, inelastic and glory quenching, etc
Quench rate effect on martensite start temperature and fine structure of Fe-C and Fe-C-Ni steel, using transmission electron microscopy
Alloy strengthening mechanisms - strengthening by fine particle dispersion, and structure and properties control by rapid quenching or splat cooling of liquid metals
Direct current quenching of alternating current electroluminescence in zinc sulfide phosphors
Oxygen collisional quenching rate in F region determined by comparing nightglow intensities with intensities calculated from electron density profiles
Quenched MnBi thin films measured for magnetic, magneto-optical and optical properties, noting Faraday rotation
Quenching efficiency of molecular oxygen relative to nitrogen, carbon monoxide, carbon dioxide and argon, involving photolysis of gas mixtures
Relaxation method for direct measurement of molecular oxygen quenching rate constants in discharge flow system
Quenching rates for oxygen during 1470 A pulse photolysis in carbon dioxide, nitrogen and helium mixtures
Quenched and aged Pt, investigating secondary defects for vacancies clustering modes by transmission electron and field-ion microscopy
Absorption spectra enhancement by organic dye laser quenching, considering applications for absorbing species spectroscopic detection
Carbon monoxide in metastable state, considering quenching and radiative lifetime
In the experiment discussed molecular oxygen was allowed to mix with atomic hydrogen and ozone at the entrance to a 3-m flow tube. A rate equation for the decay of the vibrationally excited hydroxyl is derived, taking into consideration the reaction with ozone, radiative decay, wall quenching, and interaction with molecular oxygen. It is pointed out that molecular oxygen might be important as a quencher for the hydroxyl airglow in the upper atmosphere in spite of negative results obtained in fast-flow experiments conducted in the laboratory.-
Demonstration that rapid dissociative recombination of CO2(+) in a flowing, helium afterglow is an efficient source of CO in the a super 3 pi metastable state. Ions produced by mixing CO2 with He(2 super 3 S) recombine to produce a CO metastable afterglow with a number density as great as 10 to the 9th per sq cm. Monitoring of the (a super 3 pi-X super 1 sigma) Cameron transition in CO was used to study the lifetime and quenching of CO (a super 3 pi) by CO2, N2, NO, and He. Recombination of CO2(+) also produces CO in the d super 3 delta and a' super 3 sigma states.
The 7075 alloy belonging to the Al-Zn-Mg-Cu system, prepared by powder metallurgy techniques, was used in a study of alloys prepared from splat-quenched foils consolidated into bar material by hot extrusion. Ni and Fe were included in one alloy specimen, producing a fine dispersion of FeAl3 type particles which added to the strength of the aged alloy but did not coarsen upon heat treatment. Fine oxide films showing up on air-splatted foils induce finely dispersed oxide stringers (if the foils are not hot-worked subsequently) which in turn promote axial cracking (but longitudinal tensile strength is not seriously impaired). Splatting in a protective atmosphere, or thermomechanical processing, is recommended to compensate for this.
An analysis is conducted of a typical stellar helium shell flash cycle. A sequence of 12 flashes for a population I star is considered. The changes taking place at a constant mass layer in the helium-burning shell are studied as the flash develops. A highly simplified mathematical description is presented, taking into account the three necessary conditions for the occurrence of the flash and the pressure-density and temperature-density relationships. Quantities which are helpful in explaining what triggers the flash are found to be useful in explaining what quenches the flash.
Investigations in four different areas were carried out to further our understanding of the chemistry of the atmospheres of Mars and Venus. CO2 photodissociation quantum yields were determined in the 1300-1500 A spectral region by measuring both CO and oxygen atoms. The O(1S) quantum yield was determined for CO2 photodissociation in the 1060-1175 A spectral region. The measurement resolves the differences between two earlier experiments, and demonstrates that the O(1S) yield is unity throughout most of the measured region. The pathways for the quenching of O(1S) by N2O, CO2, H2O and NO were investigated and the source of the Venus nightglow, detected by Venera 9 and 10, was investigated. What appears to be a new O2 band system, was detected although the identity of the transition is not yet evident.