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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 1,045 records · Page 58
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Apollo 14 breccias - General characteristics and classification.

The Apollo 14 breccias are complex and are characterized by a wide range of clast types and textures. The principal fragment types in the breccias are (1) hornfelsed noritic microbreccias; (2) micronorite hornfels; (3) devitrified glass; and (4) ophitic and other kinds of basalt. Based on fragment population, nature of the matrix, grain size and porosity, metamorphic history, and bulk chemical composition, the Apollo 14 breccias can be classified chiefly into regolith microbreccias, Fra Mauro breccias, and spherule-rich microbreccias. Further subdivisions are based principally on the interpretation of metamorphic history. Twenty-six Apollo 14 breccias have been so classified. The complex fragment types contained in Apollo 14 breccias represent multiple episodes of heating and fragmentation. They probably are pre-Imbrian and were not produced by the impact effects of a single event. The variability of their fragment populations is important in the interpretation of pre-Imbrian geologic history.

Chao, E. C. T.↗
NASA NTRS1973

Apollo 16 rocks - Petrology and classification.

The Apollo 16 rocks are classified in three broad intergradational groups: (1) crystalline rocks, subdivided into igneous rocks and metaclastic rocks, (2) glass, and (3) breccias, which are subdivided into five groups on the basis of clast and matrix colors. Most of the rocks were derived by impact brecciation of an anorthosite-norite suite but may represent ejecta from more than one major basin. First-cycle breccias are believed to have consisted of clasts of crushed anorthosite-norite in a fine-grained partly fused matrix with a chemical composition similar to that of the clasts. Most of the other recognized breccia types could have been produced by rebrecciation of first-cycle breccias.

Wilshire, H. G.↗
NASA NTRS1973

Classification and distribution of WR stars and an interpretation of the WN sequence.

New observational data for Wolf-Rayet stars are interpreted in areas of atmospheric abundances, absolute magnitudes, Galactic distribution, distribution in M33, and bolometric luminosities. The observational data are used in support of arguments (1) that WN stars are helium stars of eight to fourteen solar masses with atmospheres which contain only a very low proportion of hydrogen, (2) that the properties of the stars are very sensitive to this very small amount of hydrogen, and (3) that consequently this structure explains many of the general properties of the subclasses.

Smith, L. F.↗
NASA NTRS1974

Remote sensing in Iowa agriculture: Identification and classification of Iowa's crops, soils and forestry resources using ERTS-1 and complimentary underflight imagery

The author has identified the following significant results. Springtime ERTS-1 imagery covering pre-selected test sites in Iowa showed considerable detail with respect to broad soil and land use patterns. Additional imagery has been incorporated into a state mosaic. The mosaic was used as a base for soil association lines transferred from an existing map. The regions of greatest contrast are between the Clarion-Nicollet-Webster soil association area and adjacent areas. Landscape characteristics in this area result in land use patterns with a high percentage of pasture, hay, and timber. The soil association areas of the state that have patterns interpreted to be associated with intensive row crop production are: Moody, Galva-Primghar-Sac, Clarion-Nicollet-Webter, Tama-Muscatine, Dinsdale-Tama, Cresco-Lourdes, Clyde, Kenyon-Floyd-Clyde, and the Luton-Onawa-Salix area on the Missouri River floodplain. Forestland estimates have been attained for an area in central Iowa using wintertime ERTS-1 imagery. Visual analysis of multispectral, temporal imagery indicates that temporal analysis for cropland identification and acreage analyses procedures may be a very useful tool. Combinations of wintertime, springtime, and summertime ERTS-1 imagery separate most vegetation types. Timing can be critical depending upon crop development and harvesting times because of the dynamic nature of agricultural production.

Mahlstede, J. P.↗
NASA NTRS1974

Classification, scale series and nomenclature of lunar charts

Lunar charts are classified with an eye toward solution of special problems of lunar cartography. The initial state of mapping the moon will require charts with scales of 1:5,000,000; 1:1,000,000; 1:250,000; 1:50,000; and 1:10,000.

Florenskiy, K. P.↗
NASA NTRS1974

Interferometric methods for measurement of ultrasonic wave velocity: Classification, characteristics and basic defects

Interferometric methods may be considered to include all methods in which the time necessary for a signal to pass through a medium is determined on the basis of the period of oscillation of which the signal consists, while the distance is determined by noting the coincidence between (1) interference between the measured signal and its reflection and ultrasonic interference, or between another signal serving as a reference and electrical interference in the electronic part of the device. In general, all interferometric methods are relatively simple and permit a high degree of accuracy. Theoretically 48 different variations may be distinguished, about 30 of which are capable of practical application. For liquids, where transverse waves do not exist, the number of possible variations is limited to 40, assuming that absolute velocity measurement is desired.

Kozlowski, Z.↗
NASA NTRS1972

Remote sensing applications to forest vegetation classification and conifer vigor loss due to dwarf mistletoe

Criteria was established for practical remote sensing of vegetation stress and mortality caused by dwarf mistletoe infections in black spruce subboreal forest stands. The project was accomplished in two stages: (1) A fixed tower-tramway site in an infected black spruce stand was used for periodic multispectral photo coverage to establish basic film/filter/scale/season/weather parameters; (2) The photographic combinations suggested by the tower-tramway tests were used in low, medium, and high altitude aerial photography.

Douglass, R. W.↗
NASA NTRS1974

Automatic classification of eutrophication of inland lakes from spacecraft data

The author has identified the following significant results. Spacecraft data and computer techniques can be used to rapidly map and store onto digital tapes watershed land use information. Software is now available by which this land use information can be rapidly and economically extracted from the tapes and related to coliform counts and other lake contaminants (e.g. phosphorus). These tools are basic elements for determining those land use factors and sources of nutrients that accelerate eutrophication in lakes and reservoirs.

Rogers, R. H.↗
NASA NTRS1974

Develop a land use-peak runoff classification system for highway engineering purposes

The author has identified the following significant results. Based on the detail study of the Sunkhaze Stream Watershed, it is believed that good detailed drainage studies can be derived from repetitive ERTS imagery. Land use maps tailored to hydrologic study can be prepared from ERTS imagery. Significant changes in the Sunkhaze Stream and Otter Stream Watersheds at spring flood conditions have given important information on the causes for flooding in the town of Bradley.

Stoeckeler, E. G.↗
NASA NTRS1973

Synthetic aperture radar system design for random field classification

An optimum design study is carried out for synthetic aperture radar systems intended for classifying randomly reflecting areas (such as agricultural fields) characterized by a reflectivity density spectral density. The problem solution is obtained, neglecting interfield interference and assuming areas of known configuration and location, as well as a certain Gaussian signal field property. The optimum processor is nonlinear, but includes conventional matched filter processing. A set of summary design curves is plotted, and is applied to the design of a satellite synthetic aperture radar system.

Harger, R. O.↗
NASA NTRS1973

Classification, distribution, and origin of lithic fragments from the Hadley-Apennine region

The mineralogy and petrology of sixteen Apollo 15 soil samples from six stations are described together with the mineralogy, petrology, and chemistry of nineteen 4 to 10 mm basaltic lithic particles from nine stations. The lithic samples are classified, and relative abundances of the various rock types in the different samples are determined. The data are used to discuss the origin of the lithic types and their distribution according to selenological terranes. Population studies on particles in the 0.5 to 4 mm size range reveal systematic differences among three selenological terranes corresponding to the Appenine Front, the Mare/Rille, and the ridge or ray locations.

Powell, B. N.↗