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At least 991 records · Page 55
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Phase equilibria study of pseudobrookite type minerals

Pseudobrookite, is found in volcanic rocks, and the mineral armalcolite ((Fe,Mg)Ti2O5) found in the Apollo 11 and subsequent lunar samples seems to be unique to the moon. In plutonic rocks on the earth, ilmenite and rutile were found with what appears to be an equilibrium liquidus texture, while on the moon armalcolite often appears to be the primary liquidus phase among Ti-oxides. This suggests that total pressure may be a factor in the formation of these minerals, and a knowledge of the phase relations in this system yields information about the pressure under which a given magma crystallized.

Friel, J. J.↗
NASA NTRS1974

The formation of goethite and hydrated clay minerals on Mars

Laboratory studies reported by Huguenin (1973) on the kinetics and mechanism of the photostimulated oxidation of magnetic and preliminary laboratory data on the weathering of silicates, reported herein, are applied to Mars. Basalts in the Martian dark areas are predicted to alter to hydrated Fe(2 plus or minus) depleted clay minerals, minor goethite, and minor to trace amounts of transition metal oxides such as TiO2, MnO2, and Cr2O3 at a rate of 10 to the minus 1.5 plus or minus 1.5 micron/yr. Some Ca-Mg carbonates are also expected to be formed. The clay minerals are predicted to be more silica-rich than the silicate source material, SiO2 contents of 60% or higher being expected, and strongly depleted in Fe(2+). The oxygen, OH, and H2O contents of the bulk weathering product are predicted to be significantly greater than those of the dark-area source materials, whereas the relative bulk metal abundances should be the same.

Huguenin, R. L.↗
NASA NTRS1974

Bone mineral computation with a rectilinear scanner

A portable rectilinear transmission scanner and associated computerized data reduction techniques for estimating bone mineral content are described. This unit can be easily disassembled for transport to various measurement sites and has been used to estimate the bone mineral content of the os calcis, radius, and ulna in the Apollo and Skylab astronauts. The scanner is used to obtain multiple rows of data from which a bone profile is derived. Bone edges are determined with the aid of a digital computer program which employs an algorithm that determines the greatest rate of change of the counting rate.

Ullman, J.↗
NASA NTRS1974

Bone mineral content in normal US whites

Photon absorptiometry with I-125 was used to measure the bone mineral content and the bone width on 763 children between the ages of 5 and 19 years, on 538 adults between the ages of 20 and 49 years, and on 550 adults over the age of 50 years. Measurements were made on the midshaft and the distal end of the radius and the ulna, and on the humerus midshaft. This has permitted analysis of annual bone growth in children, and the rate of change in elderly adults per decade. Male and female children grew at about the same rate until adolescence. After adolescence females grew at a slow rate until the mid-twenties, while males reached adult mineralization by age 20. Males remained relatively constant until the fifties, and females began their decline in the forties.

Mazess, R. B.↗
NASA NTRS1974

Tibial bone mineral distribution as influenced by calcium, phosphorus, and vitamin D feeding levels in the growing turkey

Roentgen signs, subperiosteal, endosteal, and trabecular bone growth are evaluated in turkeys fed phosphorus at the 0.5, 0.56, 0.68, 0.90, and 2.70 percent levels. Calcium levels of 0.30, 0.40, 0.60, 1.2, and 3.60 percent were also tested. Vitamin D levels of 0, 100, 300, 900 and 27,000 I.U. per day were likewise evaluated. Roentgen signs, bone mineral as measured by T-125 gamma ray absorption, and bone mineral growth patterns as shown by radiograph area projection are correlated with calcium, phosphorus, and vitamin D feeding levels. Differences in bone growth at the various feeding levels were observed which were not reflected by differences in other studied parameters.

Spurrell, F. A.↗
NASA NTRS1974

Bone mineral changes in the Apollo astronauts

Loss of mineral from bone during periods of immobilization, recumbency or weightlessness have been observed. These losses are more apparent in the lower extremity than the upper and have been observed to exceed 30% in the case of the central os calcis during 36 weeks of bedrest. In early Gemini studies using X-ray densitometry, large losses of bone mineral were observed in the radius and ulna. This observation was not validated in the Apollo 14, 15 and 16 crewmen when a more precise technique, gamma ray absorptiometry, was used. The large losses reported for the early Gemini missions were not seen when this new measuring technique was employed.

Vogel, J. M.↗
NASA NTRS1974

X-ray diffraction identification of minerals in lunar regolith returned by Luna 16 automatic station

The methods of powder and monocrystal X-ray diffraction served in identifying the mineral composition of gross samples of regolith from different levels of the drill core and about 80 individual regolith particles returned by the Luna 16 station. It was established that the Sea of Fertility regolith includes pyroxenes of the augite-pigeonite series, anorthites, ilmenite, olivines, spinels, alpha cristobalite, iron particles, glass, and several as yet unidentified particles. Crystallographic and roentgenometric data are given for all the lunar minerals found.

Makarov, Y. S.↗
NASA NTRS1975

Study of bone mineral metabolism

The use of Sr-85 as an indicator of the skeletal location and relative amount of bone demineralization which occurs during immobilization of the body or body parts, bed-rest or space flight was studied. The bone mineral replacement which occurs after immobilization was measured rather than the bone loss which occurs during immobilization. In a study with two adult beagle dogs, the Sr-85 uptake in a leg which had been immobilized for two months was 400 percent higher than the uptake in the legs in regular use. This increased uptake probably resulted from only a few percent loss in bone mineral and indicates that losses less than one percent can be easily detected and located. The sensitivity, simplicity, and low radiation dose associated with the use of this method indicates that it should receive consideration for use on humans in bed-rest and space flight studies. Methods for measuring changes in total body nitrogen and in assisting the Johnson Space Center in calibrating a whole body counter for total body potassium measurements were also investigated.

Palmer, H. E.↗
NASA NTRS1975

Evaluation of the effects of hypergravity exposure and caging restraint on bone mineralization in the Beagle by in vivo photon absorptiometry

Photon absorptiometry was used to evaluate bone mineral kinetics associated with normal development and the possible perturbations to bone development resulting from hypergravity exposure over a period of six months in developing Beagles. A series of seven measurements were performed at specific times with the first measurement prior to treatment and subsequent measurements at 2, 5, 9, 14, 20 and 26 weeks from the onset of the experiment. Four groups of six male Beagle pups, ranging in age from 85 to 92 days were studied. Two groups were chronically exposed to hypergravity treatments by centrifugation of 2.0 G (18.0 RPM, 11.7 ft radius) and 2.6 G (18.0 RPM, 19.8 ft radius) for the 26 week period. A third group of six dogs served as a caged control to evaluate possible changes due to confinement in small plexiglass cages similar to those of the centrifuge. Thus this control group was subjected to limited exercise due to caging restraint. The fourth group of animals was housed in open runs to allow exercise without the spatial confinement of the smaller plexiglass cages. Results show highly significant differences in body weight, bone length, increase in bone density of control group relative to other groups, and a decrease in bone mineral content in the two gravity treated groups.

Fisher, G. L.↗
NASA NTRS1974

Skylab S-192 ratio codes of soil, mineral, and rock spectra for ratio image selection and interpretation

A limited theoretical systems study is made of the Skylab S-192 12-channel multispectral scanner's capabilities for geological remote sensing. Laboratory spectra of rocks, minerals, soils, and some vegetation were used to rank the twelve channels and the best twelve of the 66 possible nonreciprocal spectral ratios according to their ability to discriminate among 17 classes of geological targets. Environmental and instrumental noise sources were ignored. The S-192 should be most useful for discriminating minerals deposited by hydrothermal alteration, weathering, and evaporation. Discrimination of igneous rocks will be difficult. Ratio images are recommended over automatic discrimination methods for those geological targets that can be enhanced by ratio imaging. Ratio codes were found for the twelve highest ranked ratios, for use in selecting the ratio images which will best enhance a target of interest. They can also be searched for false alarm candidates for a given target.

Vincent, R. K.↗
NASA NTRS1974

Petrology of basalt and single-mineral fragments in the soil of the Sea of Fertility

Basalt and single-mineral particles, ranging from 150 to 425 microns, from the Luna-16 sample are studied by electron microanalysis, X-ray fluorescence analysis, and petrographic techniques. Three basalt species of different structure are identified. The structure and composition of the individual minerals (in particular of pyroxenes) indicate that the basalts have crystallized under conditions similar to those established for Apollo-11 samples.

Bence, A. E.↗
NASA NTRS1974

Geologic and mineral and water resources investigations in western Colorado using ERTS-1 data

The author has identified the following significant results. Most of the geologic information in ERTS-1 imagery can be extracted from bulk processed black and white transparencies by a skilled interpreter using standard photogeologic techniques. In central and western Colorado, the detectability of lithologic contacts on ERTS-1 imagery is closely related to the time of year the imagery was acquired. Geologic structures are the most readily extractable type of geologic information contained in ERTS images. Major tectonic features and associated minor structures can be rapidly mapped, allowing the geologic setting of a large region to be quickly accessed. Trends of geologic structures in younger sedimentary appear to strongly parallel linear trends in older metamorphic and igneous basement terrain. Linears and color anomalies mapped from ERTS imagery are closely related to loci of known mineralization in the Colorado mineral belt.

Knepper, D. H.↗
NASA NTRS1975

Mineral target areas in Nevada from geological analysis of LANDSAT-1 imagery

Geological analysis of LANDSAT-1 Scene MSS 1053-17540 suggests that certain known mineral districts in east-central Nevada frequently occur near faults or at faults or lineament intersections and areas of complex deformation and flexures. Seventeen (17) areas of analogous characteristics were identified as favorable targets for mineral exploration. During reconnaissance field trips eleven areas were visited. In three areas evidence was found of mining and/or prospecting not known before the field trips. In four areas favorable structural and alteration features were observed which call for more detailed field studies. In one of the four areas limonitic iron oxide samples were found in the regolith of a brecciated dolomite ridge. This area contains quartz veins, granitic and volcanic rocks and lies near the intersection of two linear fault structures identified in the LANDSAT-1 imagery. Semiquantitative spectroscopic analysis of selected portions of the samples showed abnormal contents of arsenic, molybdenum, copper, lead, zinc, and silver. These limonitic samples found were not in situ and further field studies are required to assess their source and significance.

Abdel-Gawad, M.↗
NASA NTRS1976

Evaluation of LANDSAT-1 image applications to geologic mapping, structural analysis and mineral resource inventory of South America with special emphasis on the Andes Mountain region

The author has identified the following significant results. The discovery of copper mineralization along a lineament mapped in Area 7 (La Paz) has lent credence to the use of LANDSAT 1 data as a basic step in mineral exploration. In Area 9 (Copiapo Region), a number of lineaments were found to be associated with the largest copper deposits of the region. In Area 12 (Magallanes), the identification of what is believed to be a tertiary basin from LANDSAT 1 data has resulted in a new area for petroleum exploration. Band 7 images, as black and white transparencies, were found to be the most useful for geologic interpretation in both tropical vegetated areas and desert regions. Color composites made by the diazochrome process, chromaline process, and from color additive viewers provided additional information. Mosaics of LANDSAT 1 data covering 4 x 6 degrees of latitude and longitude compiled at the 1:1,000,000 scale were found to be an ideal size and format for most users.

Carter, W. D.↗
NASA NTRS1976

Bone mineral changes - The second manned Skylab mission

The mineral content of the central os calcis, and distal radius and ulna was measured by the monoenergetic photon absorptiometric technique pre- and postflight on the SL-3 crewmen. No significant changes were observed in the radius and ulna. Only the SPT showed a loss in calcaneal mineral which slowly returned to preflight levels by the 87th postflight day.

Vogel, J. M.↗
NASA NTRS1976

Application of Landsat imagery to metallic mineral exploration in Utah

Standard interpretive techniques were used to study the mosaic of two Landsat images of north central Utah including several major mining districts. Correlation of major Landsat-identified lineaments with the major metallic mining districts suggests that the Landsat-identified lineaments are fractures and that their distribution may be a valuable guide for identifying other mineralized areas. The imagery provides a more complete understanding of the geological information for identifying major tectonic and structural trends in the area. Several of the major mines are located on or closely adjacent to the intersections of at least two major lineaments. Landsat data should therefore be used to complement current mineral exploration programs.

Anderson, A. T.↗
NASA NTRS1977

Modification of os calcis bone mineral profiles during bedrest

The mineral content of the left central os calcis was determined using the photon absorptiometric technique modified for the space missions to permit area scanning, and was compared with total body calcium balance changes. The instrument consists of a rectilinear scanner that is programmed by a specially designed control module to move a low energy X-ray emitting radionuclide placed in opposition to a detector to scan the foot which is places between them. The foot is placed in a plexiglas box filled with water to provide tissue equivalence and to compensate for irregularities in thickness of tissue cover that surrounds the bone. The mineral content is obtained from basic attenuation equation.

Vogel, J. M.↗
NASA NTRS1977

Bone mineral measurement: Experiment M078

Gamma ray absorptiometric measurements on bone mineral content, in addition to calcium balance studies, were performed on male volunteers during bed rest periods of 24 to 36 weeks duration and compared to Skylab mission data. Results show that mineral losses occur from the bones of the lower extremities during missions of up to 84 days and that in general they follow the loss patterns of the bed rest situation. The level of loss observed in Spacelab crews are not of clinical concern.

Smith, M. C., Jr.↗