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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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At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Electrophoresis experiment, experiment MA-014

A continuous, free flow electrophoresis study was conducted during the Apollo Soyuz Test Project mission to investigate and evaluate the increase in sample flow rate and sample resolution achievable in space. The electrophoresis equipment was designed for the separation of four mixtures of biological cells with variable sample flow rates, buffer flow rates, and electric field gradients. Separation quality was assessed by measuring the light from a quartz lamp through the electrophoresis channel and on to a photodiode system. The preliminary results indicate that all monitored systems operated correctly during the experiment. The optical system produced a light that was too bright to discern true cell distributions, but data were received that show a distribution of separated cells.

Hannig, K.↗
NASA NTRS1976

Monotectic and syntectic alloys experiment MA-044

The flight test furnace run of the monotectic and syntectic alloys experiment was successfully performed during the Apollo Soyuz Test Project mission. All three experiment cartridges were returned intact. A second ground based test was conducted after the mission to provide one g samples with an equivalent thermal history. The examinations of all flight and ground based cartridges and ampoules have been completed. Encouraging results have been obtained in the preliminary analysis of one flight aluminum antimonide sample as compared to ground based and prototype test counterparts. In terms of reduction of the unwanted second phase, the low g sample shows a homogeneity improvement by a factor of 5 to 20. Preliminary examination of one lead zinc flight sample shows a dispersion of lead in the zinc matrix. However, complete homogenization of the material did not occur. A thermal analysis of flight data shows that the average soak temperature for the head zinc ampoules was 20 C lower than planned but 35 C above the published consolute temperature..

Ang, C. Y.↗
NASA NTRS1976

Interface markings in crystals experiment MA-060

Doped germanium single crystals with interface demarcation were successfully grown during the Apollo Soyuz Test Project mission. Interface demarcation permitted the determination of the microscopic growth behavior from the onset to the termination of solidification. Preliminary segregation analysis shows striking differences in segregation in the presence of gravity. The correlation between microscopic growth rate behavior and the composition of the solid on the microscale is being evaluated.

Gatos, H. C.↗
NASA NTRS1976

Halide eutectic growth experiment MA-131

Fiberlike sodium chloride/lithium fluoride eutectic mixtures have been produced on earth and in space by the directional solidification technique. Macroscopic and microscopic examinations were made on longitudinal and transverse sections of Apollo Soyuz Test Project space grown and earth grown ingots. It was found that samples grown in space have a higher percentage of fibers alined with the growth axis. The enhanced alinement of fibers is attributed to the absence of convection currents in the liquid during solidification. Optical transmittance measurements of transverse sections of the space grown and earth grown ingots were performed with an infrared spectrometer. For a given sample thickness, the highest transmittance was obtained from ingots grown in space. For samples of different thicknesses, grown either in space or on earth, it was found that the thinner the sample, the higher the transmittance. This is in agreement with the general optical property of transparent materials.

Yue, A. S.↗
NASA NTRS1976

Science demonstrations

Three demonstrations of scientific concepts concerning liquids were performed during the Apollo-Soyuz Test Project mission. Chemical foaming, spreading of liquids, and capillary wicking were the subjects of each demonstration photographed in space. The results clearly illustrated the basic principles, and films suitable for educational uses are now available from the first author.

Snyder, R. S.↗
NASA NTRS1976

Electromyographic analysis of skeletal muscle changes arising from 9 days of weightlessness in the Apollo-Soyuz space mission

Both integration and frequency analyses of the electromyograms from voluntary contractions were performed in one crewman of the Apollo-Soyuz Test Project mission. Of particular interest were changes in excitability, electrical efficiency, and fatigability. As a result of 9 days of weightlessness, muscle excitability was shown to increase; muscle electrical efficiency was found to decrease in calf muscles and to increase in arm muscles; and fatigability was found to increase significantly, as shown by spectral power shifts into lower frequencies. It was concluded from this study that skeletal muscles are affected by the disuse of weightlessness early in the period of weightlessness, antigravity muscles seem most affected by weightlessness, and exercise may abrogate the weightlessness effect. It was further concluded that electromyography is a sensitive tool for measuring spaceflight muscle effects.

Lafevers, E. V.↗
NASA NTRS1975

EMGAN: A computer program for time and frequency domain reduction of electromyographic data

An experiment in electromyography utilizing surface electrode techniques was developed for the Apollo-Soyuz test project. This report describes the computer program, EMGAN, which was written to provide first order data reduction for the experiment. EMG signals are produced by the membrane depolarization of muscle fibers during a muscle contraction. Surface electrodes detect a spatially summated signal from a large number of muscle fibers commonly called an interference pattern. An interference pattern is usually so complex that analysis through signal morphology is extremely difficult if not impossible. It has become common to process EMG interference patterns in the frequency domain. Muscle fatigue and certain myopathic conditions are recognized through changes in muscle frequency spectra.

Hursta, W. N.↗
NASA NTRS1976

Experiment MA-028 crystal growth

A crystal growth experiment is reported on orbital space flights. The experiment was performed during the Apollo-Soyuz Test Project. The Crystal Growth Experiment assessed a novel process for growing single crystals of insoluble substances by allowing two or more reactant solutions to diffuse toward each other through a region of pure solvent in zero gravity. The experiment was entirely successful and yielded crystals of about the expected size, quality, and number.

Lind, D. M.↗
NASA NTRS1975

Mass absorption coefficients of Parylene N at soft X-ray and vacuum-ultraviolet wavelengths

Parylene N was selected as a bandpass filter for the extreme-ultraviolet telescope, flown on the Apollo-Soyuz Test Project in July 1975. The telescope measures stellar and diffuse cosmic radiation in the wavelength region from 45 to 170 A. In connection with this application, a systematic study was conducted of the mass absorption coefficient of the Parylene N. The results of the study for the wavelength region from 44 to 2536 A are reported.

Stern, R.↗
NASA NTRS1976

Pulmonary function evaluation during the Skylab and Apollo-Soyuz missions

Previous experience during Apollo postflight exercise testing indicated no major changes in pulmonary function. Pulmonary function has been studied in detail following exposure to hypoxic and hyperoxic normal gravity environments, but no previous study has reported on men exposed to an environment that was both normoxic at 258 torr total pressure and at null gravity as encountered in Skylab. Forced vital capacity (FVC) was measured during the preflight and postflight periods of the Skylab 2 mission. Inflight measurements of vital capacity (VC) were obtained during the last 2 weeks of the second manned mission (Skylab 3). More detailed pulmonary function screening was accomplished during the Skylab 4 mission. The primary measurements made during Skylab 4 testing included residual volume determination (RV), closing volume (CV), VC, FVC and its derivatives. In addition, VC was measured in flight at regular intervals during the Skylab 4 mission. Vital capacity was decreased slightly (-10%) in flight in all Skylab 4 crewmen. No major preflight-to-postflight changes were observed. The Apollo-Soyuz Test Project (ASTP) crewmen were studied using equipment and procedures similar to those employed during Skylab 4. Postflight evaluation of the ASTP crewmen was complicated by their inadvertent exposure to nitrogen tetroxide gas fumes upon reentry.

Sawin, C. F.↗
NASA NTRS1975

An overview of NASA's space program

During the last several years, the NASA space program entered a new era. With the completion of the Apollo and Skylab programs, NASA places emphasis within its space effort on three main objectives: (1) improving the access to space and the ability to capitalize on this new capability; (2) developing the space and ground systems that will collect and interpret data related to the changing nature of the earth's natural and cultural resources to aid in solving resource and environmental problems facing the entire world; and (3) adding to the storehouse of knowledge through the continued exploration of our solar system and the universe. The paper discusses the importance of the joint USA/USSR Apollo-Soyuz Test Project (ASTP), describes the capability and status of the Space Shuttle, and outlines the important role that these two programs played in extending our ability to make more effective use of this space environment. It also summarizes the capability and the plans for satellites to monitor the earth's natural and cultural resources and to assess environmental quality. The NASA programs for exploring the solar system and the universe is reviewed.

Thome, P. G.↗
NASA NTRS1976

Low-gravity homogenization and solidification of aluminum antimonide

The III-V semiconducting compound AlSb shows promise as a highly efficient solar cell material, but it has not been commercially exploited because of difficulties in compound synthesis. Liquid state homogenization and solidification of AlSb were carried out in the Apollo-Soyuz Test Project Experiment MA-044 in the hope that compositional homogeneity would be improved by negating the large density difference between the two constituents. Post-flight analysis and comparative characterization of the space-processed and ground-processed samples indicate that there are major homogeneity improvements in the low-gravity solidified material.

Ang, C.-Y.↗
NASA NTRS1976

Electrophoretic characterization of aldehyde-fixed red blood cells, kidney cells, lynphocytes and chamber coatings

Ground-based electrokinetic data on the electrophoresis flight experiment to be flown on the Apollo-Soyuz Test Project experiment MA-011 are stipulated. Aldehyde-fixed red blood cells, embryonic kidney cells and lymphocytes were evaluated by analytical particle electrophoresis. The results which aided in the interpretation of the final analysis of the MA-011 experiment are documented. The electrophoresis chamber surface modifications, the buffer, and the material used in the column system are also discussed.

Source record↗
NASA NTRS1976

ASTP chemical and microbiological analysis of potable water

The Apollo-Soyuz Test Project procedures for potable water system servicing and the results of preflight and postflight chemical and microbiological analyses of the water are discussed. Tables show results of the analyses. The effectiveness of the water system is evaluated.

Sauer, R. L.↗
NASA NTRS1976

Quantitative determination of zero-gravity effects on crystal growth from the melt (experiment MA-060)

The purpose of experiment MA-060 was to investigate quantitatively the effects of near-zero gravity conditions on crystal growth and dopant segregation during directional solidification from the melt. Gallium-doped germanium single crystals were successfully grown from the melt with simultaneous interface demarcation during the Apollo Soyuz Test Project mission. The analysis of the experimental data indicates striking differences of dopant segregation and growth behavior in the presence and absence of gravity. The results obtained are believed to have far-reaching implications on materials processing under zero-gravity conditions and on the theory of crystal growth and segregation in general.

Gatos, H. C.↗
NASA NTRS1976

Crystal growth from the vapour phase (ASTP experiment MA-085)

The positive effects of microgravity on crystal quality and fundamental properties of the vapor transport reaction were established by analyzing the results of three transport experiments on multi-component systems performed during the Apollo Soyuz Test Project (ASTP) mission. The systems employed were GeSe(0.99)Te(0.01) - GeI4 (A), GeS(0.98)Se(0.02) - GeCl4 (B), and GeS - GeCl4-Ar (C). The crystallographic analysis is based on a direct comparison of space and ground-based (prototype) crystals, employing X-ray diffraction, microprobe, microscopic, and chemical etching techniques. The results demonstrate a considerable improvement of the space-grown crystals in terms of chemical and crystalline homogeneity, surface morphology, and bulk perfection relative to ground specimens. The confirmation of greater mass transport rates than predicted for micro-gravity by present vapor transport models is of basic scientific and practical importance for the improvement of transport models and techniques on earth and for the development of a transport model for space conditions. The internal consistency and agreement between ASTP and Skylab results obtained for different compounds, transport agents, and temperature gradients strongly support the validity of these observations. The combined findings of improved crystal quality and high mass transport rates are of technological significance for space-processing applications.

Wiedemeier, H.↗
NASA NTRS1977

Space processing on Skylab and ASTP

The Skylab and Apollo Soyuz Test Project (ASTP) missions provided the opportunity the influence of micro-gravity on the processing of various materials. The results of physical and engineering experiments in metallurgy, fluids handling and crystal growth on two space missions are discussed. The majority of the experiments concern the solidification of alloys, semiconductors, and composite materials or basic liquid-liquid and solid-liquid interactions necessary to understand complex processing. Potential advantages of space processing to several materials disciplines are identified.

Snyder, R. S.↗
NASA NTRS1977

Electrophoresis experiment. Experiment MA-014

A continuous free-flow electrophoresis study was conducted during the Apollo-Soyuz Test Project Mission to investigate and evaluate the increase in sample flow rate and sample resolution achievable in space. The electrophoresis equipment was designed for the separation of four mixtures of biological cells with variable sample flow rates, buffer flow rates, and electric field gradients. Separation quality was assessed by measuring the light from a quartz lamp through the electrophoresis channel and onto a photodiode system. The data evaluation indicates that all monitored systems operated correctly during the experiment. The optical system produced a light that was too bright to discern true cell distributions, but final analysis of scientific data by computer processing shows the expected distribution of separated cells.

Hannig, K. H.↗