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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 181 records · Page 10
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NASA NTRS1972

Experimental system, and its evaluation for the control of surgically inducted infections

The effect is reported to design, fabricate, test and evaluate a prototype experimental system for the control of surgically induced infections. The purpose is to provide the cleanest possible environment within a hospital surgery room and eliminate contamination sources that could cause infections during surgery. The system design is described. The system provides for a portable laminar flow clean room, a full bubble helmet system with associated communications and ventilation subsystems for operating room personnel, and surgical gowns that minimize the migration of bacteria. The development test results consisting of portability, laminar flowrate, air flow pattern, electrostatic buildup, noise level, ventilation, human factors, electrical and material compatibility tests are summarized. The conclusions are that the experimental system is effective in reducing the airborne and wound contamination although the helmets and gowns may not be a significant part of this reduction. Definitive conclusions with regard to the infection rate cannot be made at this time.

Tevebaugh, M. D.↗
NASA NTRS1971

On the occurrence of ferrous chloride in the clouds of Venus.

Examination of the observational basis for Kuiper's (1969) conclusion that the upper cloud layers of Venus are composed of dihydrated ferrous chloride particles. Using new spectrophotometric observations of Venus, it is found that there is no strong evidence for the Fe(2+) electronic band near 1 micron as deduced by Kuiper from the photometry of Venus by Irvine et al. (1968). Evidence for an absorption band on Venus near 0.5 micron is found to be valid, but nondefinitive in terms of the identification of ferrous iron. An absorption band near 0.39 micron appearing in the Venus photometric data of Irvine et al. (1968) is judged to be unreliable as an indicator of chemical composition, because of time-dependent variations in the violet and ultraviolet clouds and spectrum of Venus. In conclusion, it is found that the evidence for dihydrated ferrous chloride in the atmosphere of Venus is inconclusive.

Cruikshank, D. P.↗
NASA NTRS1972

In the search for extraterrestrial life

The study of stellar, planetary and galactic evolution leads to the conclusion that the phenomenon of life must be coursing through the universe. It is estimated, by means of telescopic sampling, that there are billions of stars capable of having those photochemical reactions necessary for the origin of life. One approach in the search for other life would be to deploy men and instruments in spacecraft. Radio contact with other civilizations is another approach. Finally, the question might be approached by considering life as an inevitable consequence of the evolution of matter. A survey of Martian characteristics shows the possibility of life there to be dubious. The possibility of life in other parts of the galaxy is supported by a fundamental conclusion of living matter that all organisms have a common chemical ancestry. The experiment of Urey and Miller, wherein four amino acids were obtained by subjecting a mixture of methane, ammonia, and water to an electric arc, is believed to duplicate the initial organic syntheses which led to the emergence of life on earth.

Ponnamperuma, C.↗
NASA NTRS1972

Magnetic field structure in flare-associated solar-wind disturbances.

Review of the solar-wind disturbance models proposed by Piddington (1958), Gold (1959, 1962), Parker (1961), and De Young and Hundhausen (1971), in an attempt to determine what information and conclusions can be drawn about these models by examining the interplanetary magnetic field. The conclusions reached suggest that little, if any, flux is permanently ejected during the average solar-wind disturbance.

Schatten, K. H.↗
NASA NTRS1972

Application of remote sensor data to geologic analysis of the Bonanza test site, Colorado

A variety of remote sensor data has aided geologic mapping in central Colorado. This report summarizes the application of sensor data to both regional and local geologic mapping and presents some conclusions on the practical use of remote sensing for solving geologic mapping problems. It is emphasized that this study was not conducted primarily to test or evaluate remote sensing systems or data, but, rather, to apply sensor data as an accessory tool for geologic mapping. The remote sensor data used were acquired by the NASA Earth Observations Aircraft Program. Conclusions reached on the utility of the various sensor data and interpretation techniques for geologic mapping were by-products of attempts to use them.

Lee, K.↗
NASA NTRS1972

Implications of lunar aseismicity.

The aseismicity of the moon has been interpreted by Latham et al. (1970) as an indication that the moon is relatively cold in the interior. An alternative argument is now presented. This argument suggests the reverse conclusion, that the moon is too warm to be seismic. The argument is based on known properties of materials, in particular their modes of failure under shear stress. A tentative conclusion is presented that the moon is largely aseismic because the lunar-therm lies in the stable-sliding field of rock failure. It is too warm, rather than too cold.

Thomsen, L.↗
NASA NTRS1973

Intermediate energy nucleon-deuteron scattering theory.

Sloan's conclusion (1969) that terms of the multiple-scattering series beyond single scattering contribute only to S- and P-wave amplitudes in an S-wave separable model is examined. A comparison of experiments with the calculation at 146 MeV shows that the conclusion is valid in nucleon-deuteron scattering applications.

Wilson, J. W.↗
NASA NTRS1973

Evaluation of astrophysical hypotheses.

The aim of this article is to set out a bookkeeping procedure for formalizing the process of assessing a hypothesis by comparison of conclusions drawn theoretically from this hypothesis with facts obtained by reduction of observational data. The formalism used is that of probability theory. A key role is played by Bayes's rule representing the inductive process of adjusting a degree of belief in response to new information. Formulae are derived which show (1) how the probability of each hypothesis should be adjusted in response to information concerning one item, and (2) how such estimates concerning more than one item may be combined. The procedure is illustrated by a work sheet showing how a few facts and conclusions concerning pulsars were combined to appraise the neutron-star and white-dwarf hypotheses.

Sturrock, P. A.↗
NASA NTRS1973

The early history of the lunar inclination

The effect of tidal friction on the inclination of the lunar orbit to the earth's equator for earth-moon distances of less than 10 earth radii is examined. The results obtained bear on a conclusion drawn by Gerstenkorn and others which has been raised as a fatal objection to the fission hypothesis of lunar origin, namely, that the present nonzero inclination of the moon's orbit to the ecliptic implies a steep inclination of the moon's orbit to the earth's equatorial plane in the early history of the earth-moon system. This conclusion is shown to be valid only for particular rheological models of the earth. The earth is assumed to behave like a highly viscous fluid in response to tides raised in it by the moon. The moon is assumed to be tideless and in a circular orbit about the earth. The equations of tidal friction are integrated numerically to give inclination of the lunar orbit as a function of earth-moon distance.

Rubincam, D. P.↗
NASA NTRS1974

Quality of signatures

Three conclusions are drawn on the usability, inherent variations, and noise aspects of the spectral signatures processed from data collected by the Field Signature Acquisition System (FSAS). Conclusions are based on the spectral data collected from winter wheat of the 1972/73 season, grown at Texas A and M University, College Station, Texas.

Kan, E. P. F.↗
NASA NTRS1974

Passive suppression of pogo on the space shuttle

A qualitative assessment of the tendency for pogo instability of the shuttle vehicle in the absence of suppression devices, and the effectiveness of two passive suppressors (the compliant accumulator and the resistive accumulator) in counteracting any tendency toward instability is provided. In addition, the relative effectiveness of three suppressor locations (the low pressure pump (LWOP) inlet and discharge and the high pressure pump (HPOP) inlet) is also evaluated. The primary conclusion of the study is that effective pogo suppression, with passive devices, can be accomplished at the HPOP inlet location but not at the LPOP locations. Other conclusions are drawn regarding the relative effectiveness of the two accumulator types and with respect to tentative accumulator design requirements. Finally, a number of recommendations are made regarding future studies.

Lock, M. H.↗
NASA NTRS1974

Restudy of pyroxene-pyroxene equilibration temperature for ordinary chondrite meteorites

Experimental verification of the conclusions of Van Schmus and Koffman (1967) that the equilibration temperatures of ordinary chondrites are roughly the same regardless of classification, and that these temperatures range from 770 to 860 C. The higher average relative equilibrium temperatures found are attributed to improvements in microprobe techniques, and better standards and correction procedures introduced over the last six years. Agreement is expressed with their conclusion that ordinary chondrites embody equilibria achieved within the metamorphic temperature regime and not under igneous temperatures as postulated earlier by Craig (1964) and Mueller (1964).

Bunch, T. E.↗
NASA NTRS1973

Some physical parameters of micrometeoroids

Detailed morphological parameters (depth/diameter ratio, circularity index) of microcraters in the 0.2 to 100 micron diameter range were obtained via SEM techniques for three lunar glass surfaces. The depth/diameter ratios are typically 0.5 to 0.8 with a range of 0.3 to 1.3. The circularity index varies from 0.4 to 1.0 with a pronounced maximum at 0.7 to 0.9. These parameters are compared with microcraters produced in the laboratory via electrostatic particle accelerators. The following conclusions are drawn: The great majority of observed crater depths are compatible with micrometeoroid densities of 2 to 4 g/cu cm; crater depths are incompatible for projectile densities less than 1 g/cu cm and greater than 7 g/cu cm. The circularity index of microcrater pits indicates rather equidimensional, if not spherical, projectiles. Needles, platelets and other highly irregular shapes can be excluded. Less than 5% of all craters observed may offer different conclusions.

Brownlee, D. E.↗
NASA NTRS1974

The protons and electrons trapped in the Jovian dipole magnetic field region and their interaction with Io

Detailed analysis of electrons equal to or greater than 3 MeV and of protons 0.5 to 1.8 MeV and equal to or greater than 35 MeV for both the inbound and the outbound passes of the Pioneer 10 spacecraft. Conclusive evidence is obtained that the trapped radiation in Jupiter's inner magnetosphere is maintained and supplied by inward diffusion from the outer regions of the trapped radiation zone. It is shown that the time required for isotropization of an anisotropic flux by pitch angle scattering inside L approximately equal to 6 is long in comparison with the time required for particles to diffuse inward from L approximately equal to 6 to L approximately equal to 3, that the high-energy protons were not injected at high energies by the Crand (cosmic ray albedo neutron decay) process but were accelerated in the magnetosphere of Jupiter, and that the main conclusions of this analysis are unaffected by use of either the D sub 1 or the D sub 2 magnetic field models. Theoretical studies of the capture of trapped electrons and protons by Io have been carried out, and it is found that the probability of capture by Io depends strongly upon the particle species and kinetic energy.

Simpson, J. A.↗
NASA NTRS1974

Improved (ERTS) information and its impact on U.S. markets for agricultural commodities: A quantitiative economic investigation of production, distribution and net export effects

An econometric investigation into the markets for agricultural commodities is summarized. An overview of the effort including the objectives, scope, and architecture of the analysis and the estimation strategy employed is presented. The major empirical results and policy conclusions are set forth. These results and conclusions focus on the economic importance of improved crop forecasts, U.S. exports, and government policy operations. A number of promising avenues of further investigation are suggested.

Source record↗
NASA NTRS1974

Studies of social group dynamics under isolated conditions. Objective summary of the literature as it relates to potential problems of long duration space flight

Scientific literature which deals with the study of human behavior and crew interaction in situations simulating long term space flight is summarized and organized. A bibliography of all the pertinent U.S. literature available is included, along with definitions of the behavioral characteristics terms employed. The summarized studies are analyzed according to behavioral factors and environmental conditions. The analysis consist of two matrices. (1) The matrix of factors studied correlates each research study area and individual study with the behavioral factors that were investigated in the study. (2) The matrix of conclusions identifies those studies whose investigators appeared to draw specific conclusions concerning questions of importance to NASA.

Vinograd, S. P.↗
NASA NTRS1972

Protective overcoating of films

Kodak Film Type SO-212 was emulsion overcoated with gelatin and lacquer to evaluate the feasibility of application of the coatings, any image degradation, and the relative protection offered against abrasion. Evaluated were: Eastman motion picture film lacquer Type 485, water solutions of Eastman purified Calfskin gelatin, and experimental Eastman gelatin stripping film of 4 and 6 microns. Conclusions reached were: (1) All coatings can be applied with relative ease with the only limitation being that of equipment. (2) None of the coatings degrade the processed image. (3) All of the coatings provide protection to the emulsion. These conclusions apply to any film which may be considered for overcoating.

Maas, K. A.↗
NASA NTRS1973

Surface configuration as an explanation for lithology-related cross-polarized radar image anomalies

One problem that has persisted since the development of multipolarized radar is the cause or causes of differential depolarization which is expressed as tonal reversals between like- and cross-polarized images of certain outcrops. Rocks producing anomalously low returns on the cross-polarized image could be classed into three general types: (1) certain geologically recent lava flows (late Pleistocene and Holocene), (2) some tertiary volcanics and (3) certain massive sandstones. Differential depolarization has been produced by volcanic rocks of various compositions including rhyolite, rhyodacite, dacite, andesite, and basalt. This has led to the conclusion that differential depolarization is not directly caused by any compositional factor. However, the study of aerial photos and subsequent field observation have led to the conclusion that the weathering and other surface characteristics of the outcrops are responsible for their appearance on multipolarized imagery.

Mccauley, J. R.↗