On the composition of the Venus clouds.
Venus clouds composition from spectroscopic data analysis, discussing carbon dioxide, water, ice and other possible radiation scatterers
Rea, D. G.↗
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Results for “Composition B”
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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The chemical composition of galactic and solar cosmic rays.
Chemical composition of galactic and solar cosmic rays, discussing differences from universal cosmic abundances, using Cerenkov counters, emulsions, etc
Mcdonald, F. B.↗
Effective thermal expansion coefficients and specific heats of composite materials
Composite materials macroscopic thermoelastic properties relationships to constituents properties, discussing effective thermal expansion coefficients and specific heats
Hashin, Z.↗
Spectra and charge composition of the low energy galactic cosmic radiation from Z equals 2 to 14
Low energy galactic cosmic radiation energy spectra and charge composition in 2-14 Z range by OGO-5, suggesting two component model for origin
Balasubrahmanyan, V. K.↗
Determining body composition by radiation absorption spectrometry
Fat lean cellular and bone mineral mass determination in living bodies, using radiation absorption spectrometry
Cameron, J. R.↗
Alteration of lunar optical properties - Age and composition effects
Age and composition effects on lunar surface processes and optical properties, explaining main albedo, maria, color contrasts and temporal changes
Adams, J. B.↗
Absolute frequency of an atomic hydrogen maser clock
An accurate determination was made of the unperturbed atomic hydrogen ground state hyperfine transition frequency (F=1,m=0 - F=0,m=0) in reference to present world wide realizations of internationally defined time interval. In relation to the international atomic time system, the composite value is 1,420,405,751.7755 plus or minus 0.0031 HZ.
Peters, H. E.↗
Fabrication studies of Nb3Al superconductors.
Study aimed at developing fabrication techniques for the production of stabilized conductors containing both binary and ternary intermetallics of the Nb-Al system. Processes are described that offer a foundation for practical fabricating techniques suitable for the production of long lengths of stabilized Nb3Al superconductor. Once the parameters are optimized, it is conceivable that multistrand twisted composites of both binary and ternary intermetallics should become feasible.
Worzala, F. J.↗
Black silicate paints: Formulation and performance data on OSO-H
Formulations and general procedures are given for making and applying space environmentally, as well as atmospherically stable black silicate paints. Compositions are given which meet spacecraft self-contamination requirements, have excellent heat resistance, and are strongly semiconductive.
Schutt, J. B.↗
Applications of the Glauber approximation to atomic collisions
Applications of the Glauber approximation to elastic and inelastic collisions of charged particles with neutral atoms are critically reviewed in an attempt to assess the utility of the Glauber approximation in the atomic collisions domain. Various alternative derivations of the Glauber amplitude formula, both for potential scattering and for composite collisions, also are described and compared. A number of possible problems for future research are listed.
Gerjuoy, E.↗
A design for a 1984 Mars rover
A Mars rover is planned for the mid-1980's as a follow-up to the Viking program, and as a prelude to a return-to-earth mission of Martian samples in the late eighties or early nineties. An overall view of the rover's configuration is presented with a summary of basic design parameters. Six subsystems are outlined: computing, with a 10 to the 8th bit bubble memory; mobility, designed for a journey of 100 km in 2 earth years; science sample acquisition, including a soil auger and hard rock drill; power, supplied by an RTG and stored in batteries; telecommunication, with 50 K bit UHF transmission relayed through an orbiter; and visual imaging, employing two television cameras, each with an 800 x 800 pixel charge coupled device. Scientific research goals include information about Martian seismic characteristics, magnetic field, surface heat flow, chemical composition, geology along a transverse, and meteorology. Attention is given to the necessity of rover autonomy from earth commands.
Dobrotin, B. M.↗
Testing of fuel/oxidizer-rich, high-pressure preburners
Results of an evaluation of high pressure combustion of fuel rich and oxidizer rich LOX/RP-1 propellants using 4.0 inch diameter prototype preburner injectors and chambers are presented. Testing covered a pressure range from 8.9 to 17.5 MN/square meters (1292 to 2540 psia). Fuel rich mixture ratios ranged from 0.238 to 0.367; oxidizer rich mixture ratios ranged from 27.2 to 47.5. Performance, gas temperature uniformity, and stability data for two fuel rich and two ozidizer rich preburner injectors are presented for a conventional like-on-like (LOL) design and a platelet design injector. Kinetically limited combustion is shown by the excellent agreement of measured fuel rich gas composition and C performance data with kinetic model predictions. The oxidizer rich test results support previous equilibrium combustion predictions.
Lawver, B. R.↗
EBIC/TEM investigations of process-induced defects in EFG silicon ribbon
Electron bombardment induced conductivity and scanning transmission electron microscopy observations on unprocessed and processed edge-defined film-fed growth ribbon show that the phosphorus diffused junction depth is not uniform, and that a variety of chemical impurities precipitate out during processing. Two kinds of precipitates are found (1) 10 nm or less in size, located at the dislocation nodes in sub-boundary like dislocation arrangements formed during processing and (2) large precipitates, the chemical composition of which has been partially identified. These large precipitates emit dense dislocations tangles into the adjacent crystal volume.
Cunningham, B.↗
Test verification of LOX/RP-1 high-pressure fuel/oxidizer-rich preburner designs
Two fuel-rich and two oxidizer-rich preburner injectors are tested with LOX/RP-1 in an investigation of performance, stability and gas temperature uniformity over a chamber pressure range from 1292 to 2540 psia. Fuel-rich mixture ratios range from 0.238 to 0.367 and oxidizer-rich mixture ratios range from 27 to 48, and carbon deposition data are collected by measuring the pressure drop across a turbine simulator flow device. The oxidizer-rich testing demonstrates the feasibility of oxidizer-rich preburners, indicating equilibrium combustion as predicted, and the measured fuel-rich gas composition and C-asterisk performance are in excellent agreement with kinetic model predictions indicating kinetically-limited combustion.
Lawver, B. R.↗
Frame Allines Fibers in Multilayer Composites
Jib ensures layers of fiber-reinforced preimpregnated tape correctly oriented in assembly of composite panels. Jig enables fast and reproductible alinement of fibers in multiaxis layups.
Clemons, J.↗
Mineralogical-petrological characterization of near-earth asteroids
The mineralogy and petrology of 17 near-earth asteroids are characterized using reflectance spectroscopy with ground-based telescopes. Assuming the surfaces are composed of cosmically abundant materials, the presence of certain mineralogical species can be determined from diagnostic absorption features and spectral characteristics which have been studied under known laboratory conditions and understood in terms of crystal-field theory. With one possible exception, the surface composition of near-earth asteroids consists of common rock-forming minerals such as olivine, pyroxene, and phyllosilicates. Opaque components are present but cannot be mineralogically identified with existing experimental data. The spectrum of 2201 Oljato cannot be interpreted in terms of common rock-forming minerals and is examined for cometary features because its high orbital eccentricity suggests a possible relation to comets, but no common cometary features are identified. The predominance of mafic silicate absorption features in spectra of near-earth asteroids (compared to the majority of main-belt asteroids) may be a primary compositional feature or may be the signature of relatively fresher asteroid material.
Mcfadden, L. A.↗
Replacement of MDA with more oxidatively stable diamines in PMR-polyimides
Studies are performed to investigate the effect of substituting 4,4'-oxydianiline and 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane for the 4,4'-methylenedianiline in PMR polyimide matrix resin. Graphite fiber reinforced composites are fabricated from unsized Celion 6000 and PMR-polyimide matrix resins having formulated molecular weights in the range of 1500 to 2400. The composite processing characteristics are investigated and the initial room temperature and 316 C (600 F) composite mechanical properties are determined. Comparative 316 C composite weight losses and 316 C mechanical properties retention after prolonged 316 C air exposure are also determined.
Alston, W. B.↗
The distribution and significance of evaporitic weathering products on Antarctic meteorites
This paper examines the occurrence of white evaporitic deposits on Antarctic meteorites from the U.S. collection, as a function of meteorite compositional group and weathering category. Evaporites occur with unusual frequency on carbonaceous chondrites. Almost two-thirds of all evaporite-bearing meteorites belong to weathering categories A, A/B, and B. Where chemical data were available, surficial evaporite deposits could be associated with elemental anomalies in meteorite interiors.
Velbel, Michael Anthony↗