Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Houston”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Multidisciplinary study of Wyoming test sites

The author has identified the following significant results. Investigation of a variety of applications of EREP photographic data demonstrated that EREP S-190 data offer a unique combination of synoptic coverage and image detail. The broad coverage is ideal for regional geologic mapping and tectonic analysis while the detail is adequate for mapping of crops, mines, urban areas, and other relatively small features. The investigative team at the University of Wyoming has applied the EREP S-190 data to: (1) analysis of photolinear elements of the Powder River Basin, southern Montana, and the Wind River Mountains; (2) drainage analysis of the Powder River Basin and Beartooth Mountains; (3) lithologic and geologic mapping in the Powder River Basin, Black Hills, Green River Basin, Bighorn Basin and Southern Bighorn Mountains; (4) location of possible mineralization in the Absaroka Range; and (5) land use mapping near Riverton and Gillette. All of these applications were successful to some degree. Image enhancement procedures were useful in some efforts requiring distinction of small objects or subtle contrasts.

Houston, R. S.↗
NASA NTRS1974

Application of the ERTS system to the study of Wyoming resources with emphasis on the use of basic data products

Many potential users of ERTS data products and other aircraft and satellite imagery are limited to visual methods of analyses of these products. Illustrations are presented from Wyoming studies that have employed these standard data products for a variety of geologic and related studies. Possible economic applications of these studies are summarized. Studies include regional geologic mapping for updating and correcting existing maps and to supplement incomplete regional mapping; illustrations of the value of seasonal images in geologic mapping; specialized mapping of such features as sand dunes, playa lakes, lineaments, glacial features, regional facies changes, and their possible economic value; and multilevel sensing as an aid in mineral exploration. Examples of cooperative studies involving botanists, plant scientists, and geologists for the preparation of maps of surface resources that can be used by planners and for environmental impact studies are given.

Houston, R. S.↗
NASA NTRS1974

Lunar soil properties and soil mechanics

The long-range objectives were to develop methods of experimentation and analysis for the determination of the physical properties and engineering behavior of lunar surface materials under in situ environmental conditions. Data for this purpose were obtained from on-site manned investigations, orbiting and softlanded spacecraft, and terrestrial simulation studies. Knowledge of lunar surface material properties are reported for the development of models for several types of lunar studies and for the investigation of lunar processes. The results have direct engineering application for manned missions to the moon.

Mitchell, J. K.↗
NASA NTRS1973

Surface soil variability and stratigraphy at the Apollo 16 site

The results of penetration tests, analyses of footprint and Lunar Roving Vehicle track depths, and core tube sample data have been used to deduce details of near-surface stratigraphy (to depths of several tens of cm) and lateral variability in soil conditions. Local variations (meter scale) in penetration resistance and porosity may be large, and soil stratigraphy may be complex. Since average properties are about the same at all sites, these variations probably reflect individual cratering and depositional events. These local variations cannot be anticipated on the basis of surface appearance or behavior.

Mitchell, J. K.↗
NASA NTRS1975

Analysis of ERTS-1 imagery of Wyoming and its application to evaluation of Wyoming's natural resources

The author has identified the following significant results. The Earth Resources Technology Satellite data included the following successful applications: (1) general geologic mapping, (2) structural and tectonic studies, (3) landforms and surface processes, (4) mineral exploration, (5) land use inventories, (6) hydrologic studies, (7) investigations in agriculture and forestry, and (8) environmental quality and ecology. The chief advantages of ERTS-1 data for geologic studies are synoptic view, spectral information, and seasonal coverage. The spectral data and repetitive aspect are also important for land use and vegetation studies. Low resolution and lack of steoscopic coverage were found to be the main limitations of ERTS data.

Houston, R. S.↗
NASA NTRS1975

Development of a laser fluorosensor for airborne surveying of the aquatic environment

A field based laser fluorosensor, employing a pulsed nitrogen laser and telescope photomultiplier detector system, has been successfully tested at night from a cliff top site overlooking Lake Ontario providing target ranges greater than 274 meters. Remotely sensed spectra and amplitude changes in the fluorescence emission of natural waters have shown potential as a water quality indicator. In this connection, a convenient internal reference standard with which to gauge the amplitude of the fluorescence signal is realized in the form of the concurrent water Raman emission. Remote measurements of oil fluorescence emission spectra suggest that airborne laser fluorosensors are capable of detecting and characterizing the oil in a given slick and that environmental aging of these slicks does not significantly alter their fluorescence emission signature.

Bristow, M. P. F.↗
NASA NTRS1975

LIFES: Laser Induced Fluorescence and Environmental Sensing

A laboratory investigation has been conducted to evaluate the detection and identification capabilities of laser induced fluorescence as a remote sensing technique for the marine environment. The relative merits of fluorescence parameters including emission and excitation profiles, intensity and lifetime measurements are discussed in relation to the identification of specific targets of the marine environment including crude oils, refined petroleum products, fish oils and algae. Temporal profiles displaying the variation of lifetime with emission wavelength have proven to add a new dimension of specificity and simplicity to the technique.

Houston, W. R.↗
NASA NTRS1975

Positronium-hydrogen elastic scattering

Elastic scattering of positronium atoms by hydrogen atoms below the excitation threshold at 5.1 eV is investigated with the investigation limited to the spin-zero (singlet) state of the two electrons. Nonresonant S-wave phase shifts have been obtained from normalizable trial functions by extracting the center-of-mass wave function and examining its spatial behavior. An effective-range expansion is fitted to the phase shifts and the previously obtained positronium-hydride bound-state energy to yield a scattering length approximately equal to 5.3 Bohr radii as compared with Fraser's (1961) corrected exchange result of 7.28 Bohr radii. The stabilization method suggests that a resonance occurs at a scattering energy of 4.5 eV, about 0.6 eV below the excitation threshold. Using the complex-rotation method, evidence is obtained which confirms the existence of the resonance, and its width is estimated to be about 0.06 eV.

Drachman, R. J.↗
NASA NTRS1976

Application LANDSAT imagery to geologic mapping in the ice-free valleys of Antarctica

The author has identified the following significant results. Studies in the Ice-Free Valleys are resulted in the compilation of a sizeable library of maps and publications. Rock reflectance measurements were taken during the Antarctic summer of 1973. Spectral reflectance of rocks (mostly mafic lava flows) in the McMurdo and Ice-Free Valleys areas were measured using a filter wheel photometer equipped to measure reflectances in the four Landsat bands. A series of samples were collected at regular intervals across a large differentiated, mafic sill near Lake Vida. Chemical analyses of the sample suggest that the tonal variations in this sill are controlled by changes in the iron content of the rock. False color images were prepared for a number of areas by the diazo method and with an optical multispectral biviewer. These images were useful in defining boundaries of sea ice, snow cover, and in the study of ablating glaciers, but were not very useful for rock discrimination.

Houston, R. S.↗
NASA NTRS1975

Multidisciplinary study on Wyoming test sites

The author has identified the following significant results. Ten EREP data passes over the Wyoming test site provided excellent S190A and S190B coverage and some useful S192 imagery. These data were employed in an evaluation of the EREP imaging sensors in several earth resources applications. Boysen Reservoir and Hyattsville were test areas for band to band comparison of the S190 and S192 sensors and for evaluation of the image data for geologic mapping. Contrast measurements were made from the S192 image data for typical sequence of sedimentary rocks. Histograms compiled from these measurements show that near infrared S192 bands provide the greatest amount of contrast between geologic units. Comparison was also made between LANDSAT imagery and S190B and aerial photography for regional land use mapping. The S190B photography was found far superior to the color composite LANDSAT imagery and was almost as effective as the 1:120,000 scale aerial photography. A map of linear elements prepared from LANDSAT and EREP imagery of the southwestern Bighorn Mountains provided an important aid in defining the relationship between fracture and ground water movement through the Madison aquifer.

Houston, R. S.↗
NASA NTRS1976

Numerical computations of Orbiter flow fields and heating rates

Numerical computations of flow fields around an analytical description of the Space Shuttle Orbiter windward surface, including the root of the wing leading edge, are presented to illustrate the sensitivity of these calculations to several flow field modeling assumptions. Results of parametric flow field and boundary layer computations using the axisymmetric analogue concept to obtain three-dimensional heating rates, in conjunction with exact three-dimensional inviscid floe field solutions and two-dimensional boundary layer analysis - show the sensitivity of boundary layer edge conditions and heating rates to considerations of the inviscid flow field entropy layer, equilibrium air versus chemically and vibrationally frozen flow, and nonsimilar terms in the boundary layer computations. A cursory comparison between flow field predictions obtained from these methods and current Orbiter design methods has established a benchmark for selecting and adjusting these and future design methodologies.

Goodrich, W. D.↗
NASA NTRS1977

Gold recovery process from polyimide film

Process economically separates gold from goldized polyimide film and other nonmetallic scrap without hazards of conventional processes. Technique uses nitric acid to destroy nonmetallic material, leaving gold intact.

Houston, D. W.↗
NASA NTRS1971

Gravity gradient preliminary investigations, part 2: Lunar tidal gravity gradients and stresses (exhibit C)

Preliminary analysis of the gravity gradients associated with gravity tides on the moon caused by the earth indicates that the relative changes in the gradients are very irregular, and large, and about 15 times greater than those experienced on earth. Thus gradients, in preference to gravity tides themselves, may well be an important key in correlating tide effects with lunar transient events and moonquakes, and also in determining triggering mechanisms for crustal movement and faulting. Preliminary analysis of lunar crustal stresses and strains caused by lunar gravity tides indicates that these factors may be more direct causative agents or triggering mechanisms. In particular, the cubic dilation undergoes relatively large changes and is about 11 times greater on the moon than on earth. Thus it should be correspondingly more important.

Houston, M. H.↗
NASA NTRS1977

Earth observations from remote-sensing platforms - Outlook

Observations of the earth from remote-sensing platforms are discussed noting the NASA Earth Resources Aircraft Program, Earth Resources Technology Satellite program, and the Earth Resources Experiments Package. Techniques for geological mapping are described including automatic mapping, visual interpretation, band selection, radar, band combination, and image enhancement.

Houston, R. S.↗
NASA NTRS1979

Determining resin/fiber content of laminates

Article discusses procedure where hydrazine is used to extract graphite fibers from cured polyimide resin. Method does not attack graphite fibers and is faster than hot-concentrated-acid digestion process.

Garrard, G. G.↗