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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Effect of weightlessness on mineral saturation of bone tissue

X-ray photometry of bone density established dynamic changes in mineral saturation of bone tissues for Soyuz spacecraft and Salyut orbital station crews. Calcaneus optical bone densities in all crew members fell below initial values; an increase in spacecrew exposure time to weightlessness conditions also increased the degree of decalcification. Demineralization under weightlessness conditions took place at a higher rate than under hypodynamia.

Krasnykh, I. G.↗
NASA NTRS1974

Formational history of lunar rocks - Applications of experimental geochemistry of the opaque minerals

Experimental data on the cooling histories of lunar rocks are presented along with a descriptive mineralogy of certain opaque minerals in Apollo 17 samples. Lunar rocks having Zr partitionings of coexisting ilmenite and ulvospinel indicative of high-temperature equilibrium (above 1000 C) appear to have cooled rapidly to temperatures below 800-900 C. The Ti content of troilite coexisting with ilmenite can be used to differentiate rock fragments which are mineralogically and texturally similar. It is found that Cr and Mg partitionings between coexisting armalcolite and ilmenite vary notably between rocks so that they can be used to distinguish otherwise similar samples. The spinels are analyzed as varieties of chromian ulvospinel and titanian chromite.

Taylor, L. A.↗
NASA NTRS1974

Identification of Geostructures of the Continental Crust Particularly as They Relate to Mineral Resource Evaluation

The author has identified the following significant results. A pattern of very old geostructures was recognized, reflecting structures in the crust. This pattern is not peculiar to Alaska, but can be recognized throughout the northern cordillera. A new metallogenic hypothesis for Alaska was developed, based on the relationship of space image linears to known mineral deposits. Using image linear analysis, regional geologic features were also recognized; these features may be used to guide in the location of undiscovered oil and/or gas accumulations in northern Alaska. The effectiveness of ERTS data in enhancing medium and small scale mapping was demonstrated. ERTS data were also used to recognize and monitor the state of large scale vehicular scars on Arctic tundra.

Lathram, E. H.↗
NASA NTRS1976

Remote sensing in mineral exploration from LANDSAT imagery

The author has identified the following significant results. Preliminary statistical analysis of length and azimuth of linear stream segments in the Battle Mountain area suggest that segment length (discriminating criterion) can be used to distinguish mineralized from nonmineralized areas.

Nackowski, M. P.↗
NASA NTRS1975

Evaluation of LANDSAT-2 (ERTS) images applied to geologic structures and mineral resources of South America

The author has identified the following significant results. Work with the Image 100 clearly demonstrates that radiance values of LANDSAT data can be used for correlation of geologic formations across international boundaries. The Totora Formation of the Corocoro Group of Tertiary age was traced from known outcrops near Tiahuanaco, Bolivia, along the south side of Lake Titicaca westward into Peru where the same rocks are considered to be Cretaceous in age. This inconsistency suggests: (1) that a review of this formation is needed by joint geological surveys of both countries to determine similarities, differences, and the true age; (2) that recognition of the extension of the copper-bearing Totora Formation of Bolivia into Peru may provide Peru with a new target for exploration. Equal radiance maps made by use of the Image 100 system show as many as eight different units within salar deposits (salt flats) of the Bolivian Altiplano. Standard film processed images show them as nearly uniform areas of white because of lack of dynamic range in film products. The Image 100 system, therefore, appears to be of great assistance in subdividing the salt flats on the basis of moisture distribution, surface roughness, and distribution of windblown materials. Field work is needed to determine these relationships to mineral composition and distribution. Images representing seasonal changes should also improve the accuracy of such maps. Radiance values of alteration zones related to the occurrence of porphyry copper ores were measured at the San Juan del Abra deposit of northern Chile using the Image 100 system. The extent to which these same values may be used to detect similar alteration zones in other areas has not yet been tested.

Carter, W. D.↗
NASA NTRS1975

Geologic and mineral and water resources investigations in western Colorado, using Skylab EREP data

The author has identified the following significant results. Skylab photographs are superior to ERTS images for photogeologic interpretation, primarily because of improved resolution. Lithologic contacts can be detected consistently better on Skylab S190A photos than on ERTS images. Color photos are best; red and green band photos are somewhat better than color-infrared photos; infrared band photos are worst. All major geologic structures can be recognized on Skylab imagery. Large folds, even those with very gentle flexures, can be mapped accurately and with confidence. Bedding attitudes of only a few degrees are recognized; vertical exaggeration factor is about 2.5X. Mineral deposits in central Colorado may be indicated on Skylab photos by lineaments and color anomalies, but positive identification of these features is not possible. S190A stereo color photography is adequate for defining drainage divides that in turn define the boundaries and distribution of ground water recharge and discharge areas within a basin.

Lee, K.↗
NASA NTRS1975

The Nakhlites. I - Petrography and mineral chemistry. II - Where, when, and how

The two Nakhlite meteorites (Nakhla and Lafayette) are described, and their possible origin is discussed. It is shown that both objects are cumulates of clinopyroxene with augite as the major mineral and with lesser abundances of olivine, plagioclase, K-feldspar, Fe-Ti oxides, FeS, pyrite, chalcopyrite, and possibly iddingsite. Also, both meteorites are unbrecciated, and their texture is dominated by elongate subhedral to euhedral prisms of clinopyroxene. The data are shown to be compatible with the Nakhlites' being cumulative rocks from a common basaltic parent liquid. It is established that these objects are not of lunar origin, and it is concluded that the position of the parent body relative to other planetary bodies remains to be determined.

Bunch, T. E.↗
NASA NTRS1977

Space technology in the discovery and development of mineral and energy resources

Space technology, applied to the discovery and extraction of mineral and energy resources, is summarized. Orbital remote sensing for geological purposes has been widely applied through the use of LANDSAT satellites. These techniques also have been of value for protection against environmental hazards and for a better understanding of crustal structure.

Lowman, P. D.↗
NASA NTRS1977

Mineral and nitrogen metabolic studies, experiment M071

The similarity between bed rest test and space flight effects on human mineral and nitrogen metabolisms indicates impairment of capable musculoskeletal functions. A pattern of urinary calcium increases and total calcium shifts suggests that calcium losses continue with time. Significant losses of nitrogen and phosphorus are associated with reduction in muscle tissue. It is concluded that capable musculoskeletal function is likely to be impaired during space flights of 1 1/2 to 3 years duration.

Whedon, G. D.↗
NASA NTRS1977

Gas-rich minerals in the Allende meteorite - Attempted chemical characterization

A ten-step etching experiment with HNO3 was performed on a chromite-carbon residue from Allende, in order to characterize the HNO3-soluble minor phase 'Q' that contains most of the primordial Ar, Kr, and Xe. Each etch fraction was analyzed by neutron activation analysis for Cr, Fe, Co, Ir, and Au. The results suggest that Q consists of two minerals, each comprising about 5 per cent of the residue. Phase Q1, of Fe/Cr ratio greater than 20, is soluble in cold dilute HNO3 and seems to contain most of the heavy noble gases. It may be an HCl-insoluble sulfide of nominal composition (Fe84Ni12Cr4)Sx. Phase Q2, of Fe/Cr ratio about 0.5 and somewhat enriched in Co, is slowly soluble in hot concentrated HNO3 and seems to be at least an order of magnitude poorer in heavy noble gases than Q1. It may be daubre-elite or an acid-soluble variety of chromite.

Gros, J.↗
NASA NTRS1976

Mineral and nitrogen metabolic studies on Skylab flights and comparison with effects of earth long-term recumbency

A metabolic study of the effects of space flight on various chemical elements, particularly those with special relevance to the musculo-skeletal system, was carried out on the nine astronauts who participated in the three Skylab flights of 28, 59 and 84 days in 1973-1974. The study required of the cooperating crewmen constant dietary intake, continuous 24-hour urine collections and total fecal collections for 21-31 days before each flight, throughout each flight and for 17-18 days post-flight. Increases in urinary calcium and negative calcium balances during space flight were generally similar to those found in previous immobilization and bedrest studies. The persistence of these alterations in calcium metabolism throughout the flights suggested that calcium losses would continue in weightlessness for a very long time. Significant losses of nitrogen and phosphorus occurred, associated with observed reduction in muscle tissue. Both mineral and muscle losses occurred despite rigorous exercise regimens in flight. It was concluded that unless protective measures can be developed, capable musculo-skeletal function is likely to be impaired in space flights, ultimately to be conducted to Mars, of 1-1/2 to 3 years duration.

Whedon, G. D.↗
NASA NTRS1976

The Apollo 16 drill core - Modal petrology and characterization of the mineral and lithic component

A string of 59 polished thin sections covering the length of the Apollo 16 deep drill core has been examined. A modal analysis, involving the optical classification of 116,000 points was made, and over 500 mineral and lithic fragments from the core were chemically analyzed using an electron microprobe. These data were used to identify and characterize the source areas of the core material and to reconstruct the accumulation history of the core.

Vaniman, D. T.↗
NASA NTRS1977

Effectiveness of various organometallics as antiwear additives in mineral oil

Sliding friction experiments were conducted with 1045 steel contacting 302 stainless steel and lubricated with various organometallics in mineral oil. Auger emission spectroscopy was used to determine the element present in the wear contact zone. The results indicate that there are organometallics which are as effective an antiwear additives as the commonly used zinc dialkyl dithiophosphate. These include dimethyl cadmium, triphenyl lead thiomethoxide, and triphenyl tin chloride. The additives were examined in concentrations to 1 weight percent. With dimethyl cadmium at concentrations of 0.5 weight percent and above, cadmium was detected in the contact zone. Coincident with the detection of cadmium, a marked decrease in the friction coefficient was observed. All additives examined reduced friction, but only the aforementioned reduced wear to a level comparable to that observed with zinc dialkyl dithiophosphate.

Buckley, D. H.↗
NASA NTRS1978

Laboratory studies of the diffuse reflectance spectra of frosts and minerals occurring on astronomical objects

A vacuum monochromator was integrated into the system and optics chosen to increase data collection in the infrared spectral region. Using a InSb detector, good reflectance data was obtained to 5.5 micron from a variety of samples including magnesium oxide, barium sulfate, water frost and Bloedite. Magnesium oxide was found to be a poorer reflector than the barium sulfate throughout the visible and near infrared region. The barium sulfate material was shown to be a Lambert reflector in the visible region and over an angular range of 60 deg. Several samples of water frost were prepared and in reflectance measured from 0.3 micron to 5.5 microm. The fine grained frosts were better reflectors than the coarse grained frosts, usually by 20 percent or more, over the entire spectral range. The minerals Bloedite and sulfur were also investigated further.

Glaser, F. M.↗
NASA NTRS1977

Mars - Photodesorption from mineral surfaces and its effects on atmospheric stability

Kinetic constraints are employed to identify the reactive chemisorbed complexes, to describe the mechanism of UV-accelerated desorption from Fe (+2) on mineral surfaces, and to estimate the photodesorption rate on Mars. In particular, it is proposed that gases such as O2, CO2, CO, H2O and N2 undergo an adsorption-desorption process at octahedrally coordinated Fe (+2) surface sites to produce seven-coordinate transition-state complexes. The ligand field stabilization energy acquired by these complexes lies between 16 and 18 kcal per mole. Published photocatalysis data are used to assess the role of photodesorption in Martian atmospheric chemistry and stability.

Huguenin, R. L.↗
NASA NTRS1978

Implications of abundant hygroscopic minerals in the Martian regolith

Converging lines of evidence suggest that a significant portion of the Martian surface fines may consist of salts and smectite clays. Salts can form stoichiometric hydrates as well as eutectic solutions with depressed freezing points; clays contain bound water of constitution and adsorb significant quantities of water from the vapor phase. The formation of ice may be suppressed by these minerals in some regions on Mars, and their presence in abundance would imply important consequences for atmospheric and geologic processes and the prospects for exobiology.

Clark, B. C.↗
NASA NTRS1977

Apollo 14 - Oxide, metal, and olivine mineral chemistries in 14072 with a bearing on the temporal relationships of subsolidus reduction

One of three primary objectives of the reported study is related to the definition of the distribution of troilite and Fe and the evaluation of the role of FeS in subsolidus reduction assemblages. Another objective was concerned with the definition of the lower limit of stabilizing elements such as Mg, Al, and Cr in ulvospinel to determine the terminal compositions at which reduction is inhibited. The third objective involves a comparison of the mineral chemistries of decomposed olivine with unaltered olivine in an attempt to determine the temperature limits. The sample was selected because it is one of the most intensely reduced samples returned from the moon. The model invoked for reduction is a magmatic-deuteric process which requires an environment approximating that of a closed system in which the volatile constituents are contained and in which reduction proceeds continuously with crystallization.

Haggerty, S. E.↗