SEARCH · Engineering Papers
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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Feasibility study of secondary emission electron microscopy for examining materials containing dispersed oxide particles
Critical examination of equations for atmospheric number-density calculations, and computed values compared with observations
Similarity parameters used for examining geometry characteristics of axial flow turbines with high expansion ratio
Heredity and cytology of sex as examined in frogs
Examination of thermal oxidation deposits on heat resistant alloys using X ray diffraction and X ray flourescence analyses
Organic solvent extracts of Apollo 11 bulk fine sample examined for porphyrins using spectrofluorometry
Apollo 11 lunar dust small glassy spherules and cylinders examination by interferometry, discussing specular reflection, microcracking, chipping and origin
Optical image comparator for examination of field ion micrographs
Examination of molybdenum disulfide with LEED and Auger emission spectroscopy
Examination of simple coordinate transformations in Z-plane and W-plane for root locus analysis of sampled data systems
Ray tracing techniques for examination of refractivity profile sensitivity in tropospheric range and Doppler effects on profile shape
Returned Surveyor 3 camera visor examined for alpha radioactive deposit formed by decay of radon isotopes diffusing out of lunar surface
Apollo 12 lunar rock 12013 preliminary examination and preparation for instrumental analysis, noting feldspar content and igneous nature
Lunar surface meteoroid activity from Surveyor 3 sample examination, comparing with predictions by cumulative-flux and near-earth models
Apollo 12 returned Surveyor 3 samples examination for meteoroid and lunar ejecta impacts evidence by optical and electron microscopy
The anomalous oscillatory behavior of three satellites was examined. The satellites were all hinged, two-body, gravity gradient configurations passively stabilized about their three principal axes by gravity gradient and damper torques. Two basic behavior patterns were observed. Either the satellites were stable with attitude perturbations less than + or - 5 deg or their behavior tended towards a low frequency rigid body oscillation dominated by large yaw motions and in some cases by yaw inversions. A causal relationship between sun angle and the character of satellite behavior was observed which appears to indicate that thermal distortion is a critical factor in a gravity gradient satellite's dynamic behavior. The behavior appeared to be futher modified by the existence of response frequencies that were higher than anticipated values.
Aerial photographs taken with color infrared film were used to differentiate various types of residential areas in the Los Angeles basin, using characteristics of the physical environment which vary from one type of residential area to another. Residential areas of varying quality were classified based on these characteristics. Features of the physical environment, identifiable on CIR aerial photography were examined to determine which of these are the best indicators of quality of residential areas or social areas, as determined by the socioeconomic characteristics of the inhabitants of the selected areas. Association between several physical features and the socioeconomic variables was found to exist.
Metallic transfer between polycrystalline metals in sliding contact was examined. Hemispherical riders of iron, nickel, and cobalt were slid on tungsten, tantalum, niobium, and molybdenum disks in ultrahigh vacuum. Auger emission spectroscopy was used to monitor the elemental composition of the disk surfaces. Iron, nickel, and cobalt transferred to tungsten, whereas only cobalt transferred to tantalum, niobium, and molybdenum. The results of this investigation are discussed in terms of the cohesive energy and strain hardening characteristics of the specimen materials.