SEARCH · Engineering Papers

Results for “patch”

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.

SourceResearch connectionFrom yearThrough year

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

At least 631 records · Page 35

All sources NASA NTRS DOE OSTI

NASA NTRS1972

The morphology of displays of pulsating auroras.

An auroral substorm generates displays of pulsating auroras in ways which show a dependence upon both local time and latitude relative to the auroral oval. For several hours after midnight pulsating auroras can be observed in the wake of poleward expansions or within equatorward spreading diffuse envelopes of meridional extent of several hundred kilometers. As the dawn meridian is approached the displays of pulsating auroras tend increasingly to be comprised of distinct eastward drifting patches easily recorded by all-sky cameras.

Cresswell, G. R.↗

NASA NTRS1972

Properties of white light flares. I - Association with H-alpha flares and sudden frequency deviations.

All four large EUV bursts for which there were available concurrent white light observations of at least fair quality, were detected as white light flares. The rise times and maxima of the white light emissions coincided with rise times and maxima of the EUV bursts. The frequency of strong EUV bursts suggests that white light flares may occur at the rate of five or six per year near sunspot maximum. All of the white light flare areas coincided with intense bright areas of the H-alpha flares. These small areas appeared to be sources of high velocity ejecta in H-alpha. The white light flares occurred as several knots or patches of 2 to 15 arc-sec diameter, with bright cores perhaps less than 2 arc-sec diameter (1500 km). They preferred the outer penumbral borders of strong sunspots within 10 arc-sec of a longitudinal neutral line in the magnetic field.

Mcintosh, P. S.↗

NASA NTRS1972

The effect of membrane parameters on the properties of the nerve impulse.

The effect of varying some membrane parameters is explored, basing the investigation on computer simulation of the Hodgkin-Huxley equations for the squid giant axon, including variations in the membrane capacitance, conductances, and the rate constants. It is shown that by reducing the degree of regeneration in the excitable membrane, the character of the nerve signal can be smoothly changed from that of the axonal spike to essentially electrotonic spread, with all gradations in between. The reduction in the degree of regeneration can most simply be brought about by a decrease in the density of active membrane patches.

Sabah, N. H.↗

NASA NTRS1973

N-body U and K matrix program

Computer program was devised to compute free-fall trajectories of satellites, allowing for injection errors and midcourse velocity perturbations. Program consists of trajectory perturbing program and N-body integrating conic program which can also be used as 2-body patch conic program.

Setter, R. N.↗

NASA NTRS1973

Evaluation of proposed Skylab and SSP soap products

Three personal hygiene cleansing agents and one laundry detergent (sodium dodecyl benzene sulfonate), which are all candidates for use on long-duration space missions, were evaluated in terms of dermatological effects on human subjects and effects on microbiological species. None of the four materials exhibited adverse dermatological effects from either skin patch tests of two weeks duration or a simulated Skylab personal hygiene regimen of up to four weeks duration. No significant alterations in skin microflora during the use regimen were found. None of the four materials were found to serve as microbiological support media for the species tested, but a species of air-borne mold was observed to grow rapidly in a neutralized aqueous solution. None of the candidate agents was found to be strongly biocidal.

Whitmore, F. C.↗

NASA NTRS1972

Cayley formation interpreted as basin ejecta, part B

Improved information on the morphology and distribution of the Cayley Formation, provided by Apollo 16 orbital photography, leads to a concept in which the Cayley Formation was deposited as fluidized debris that traveled beyond the presently recognizable extent of the Imbrium Basin ejecta. By this hypothesis, each basin-forming event produced thick plains deposits in a belt peripheral to the continuous ejecta blanket and may have deposited a thinner layer in pools over the entire moon. Thus, each patch of terra plains is likely to be underlain by a sequence of fluidized ejecta deposits, which were derived from most or all multi-ring basins younger than the occupied depression. If the light color of the plains results from a high feldspar content of the excavated crustal rocks, an explanation of the absence of exposed pre-Cayley mare rocks may be that they are buried or dusted over.

Eggleton, R. E.↗

NASA NTRS1973

Detection of prescribed burn on National Forest

The author has identified the following significant results. The effects of a prescribed burn in the Sam Houston National Forest have been detected from ERTS-1 coverage of November 27, 1972. The burn was first identified on aircraft underflight photography of November 7, 1972. On color infrared aircraft photography it appeared as a green patch, indicating stressed vegetation, in an area of red coloration, indicating vigorous vegetation. It was later detected on the color composite of ERTS-1 bands 4, 5, and 7, as a black area in otherwise red vegetation. The fire, covering approximately 40 hectares (100 acres), was intentionally started to clear out heavy underbrush so that trees could be marked prior to harvesting. The significance of this observation is that a light burn of this type and its subsequent effects on vegetation could be detected on ERTS-1 imagery. Continued observation of this type of phenomenon under various conditions may provide a means of identifying such an occurrence without a prior knowledge of the event.

Erb, R. B.↗

NASA NTRS1973

Evaluation of ERTS data for certain oceanographic uses

The author has identified the following significant results. A significant result was reported 13 July on anomalous dark patches observed in certain ERTS-1 images. This sunglint related feature is possible whenever the solar elevation is greater than 55 deg and the surface waters are calm. It is observed in all MSS bands. Although the bright specular point is nearly 300 nm from nadir no bright specular returns are possible with a 0930 local time descending path-only diffuse glitter, that may reach reflectance levels of 1-2% under wind speeds of 5-10 m/sec and solar elevations greater than 60 deg.

Strong, A. E.↗

NASA NTRS1973

Analysis study of multispectral data, ERTS-A, from an area in West Pakistan

The author has identified the following significant results. Geomorphic features related to a known porphyry copper deposit at Saindak, western Chagai District, Pakistan, are easily distinguished on ERTS-1 images. No new prospecting sites were recognized on the basis of the images alone, but new information from the images was used in conjunction with known geology to evaluate two previously known speculative areas and to suggest one additional one. The study showed that Saindak-type deposits are less likely in some extensive areas of the Chagai District than formerly believed. The Saindak deposit is in an area of relatively soft folded sedimentary and volcanic rocks. The deposit is characterized by a linear zone of easily eroded sulfide-rich rock surrounded by a resistant rim of hornfels and propylitically altered rock. Both this rim and the central sulfide-rich valley are conspicuous features on the images. Swarms of dikes are probably useful for distinguishing real rims from other resistant rock types, but there is no expression of them on the image, although they are easily seen on aerial photographs of the Saindak rim. During field mapping, patches of strong red and yellow hue related to the mineral natrojarosite were noted in the central valley. Attempts to detect a color anomaly using simple false color composites were not successful.

Schmidt, R. G.↗

NASA NTRS1973

TIDY, a complete code for renumbering and editing FORTRAN source programs. User's manual for IBM 360/67

TIDY, a computer code which edits and renumerates FORTRAN decks which have become difficult to read because of many patches and revisions, is described. The old program is reorganized so that statement numbers are added sequentially, and extraneous FORTRAN statements are deleted. General instructions for using TIDY on the IBM 360/67 Tymeshare System, and specific instructions for use on the NASA/AMES IBM 360/67 TSS system are included as well as specific instructions on how to run TIDY in conversational and in batch modes. TIDY may be adopted for use on other computers.

Barlow, A. V.↗

NASA NTRS1972

IC 3576 - An unusual spiral galaxy in Virgo.

The possible association of an X-ray source with the galaxy IC 3576 was investigated in a program of optical observations of this galaxy. The observations show that patches and condensations belonging to the galaxy are distributed in a nonrandom, spiral fashion. This distinctive morphology corresponds to the dwarf spiral of the second type discussed by van den Bergh (1959). Radio observations are also considered, giving attention to a 21-cm emission due to neutral hydrogen in IC 3576. It is pointed out that the evidence at this time that the X-ray source in Virgo corresponds to IC 3576 is positional only.

Margon, B.↗

NASA NTRS1973

Evaluation of proposed Skylab and SSP soap products.

Four candidate cleansing agents evaluated in terms of potential hazards to crew members included two soaps (Neutrogena bar soap and Olive Leaf Liquid), one nonfoaming surfactant (Miranol JEM), and one laundry detergent (sodium dodecylbenzene sulfonate). None of the four exhibited adverse dermatological effects from skin patch tests or supported growth of potentially pathogenic microorganisms. Aqueous solutions of Neutrogena did support a mold species. Neutrogena and Miranol JEM were used in a simulated Skylab personal hygiene regimen with no adverse effects on skin or skin microflora. Based on our results, each of these agents appear to be a promising candidate material for the use intended.

Durfee, R. L.↗

NASA NTRS1973

An atlas of low-latitude 6300-A forbidden O I night airglow from Ogo 4 observations.

The atomic oxygen emission line at 6300 A as measured in the nadir direction by a photometer on the polar-orbiting satellite Ogo 4 has been plotted between 40 deg N and 40 deg S latitude on a series of maps for the moon-free periods between Aug. 30, 1967, and Jan. 10, 1968. Readily apparent are the longitudinal and local time variations that occur during the northern fall-winter season. The northern tropical arc is more widespread; the southern arc is not present at all longitudes. The arcs in early evening are strong and distinct, separated by very low emission rates at the magnetic equator. The arcs lie generally along magnetic parallels, move toward the magnetic equator as the night progresses, and, in the early morning hours, decrease in emission rate and degenerate into patches.

Reed, E. I.↗

NASA NTRS1973

Planetary flybys resulting in heliocentric orbits normal to the ecliptic with fixed perihelia.

An iterative procedure is applied to a patched conic trajectory sequence in which a spacecraft is launched from the earth, flys by the planet Jupiter, and leaves Jupiter along a heliocentric trajectory whose plane is normal to the ecliptic, and whose perihelion is fixed at 0.1 AU. Six launch opportunities, spaced apart in time at approximately the mean synodic period of earth and Jupiter (roughly 400 days), are examined.

Buglia, J. J.↗

NASA NTRS1973

The application of Skylab imagery to analysis of fault tectonics and earthquake hazards in the Peninsular Ranges, southern California

The author has identified the following significant results. Frame 114 of the Salton Sea area was studied in all bands to analyze the appearance of important faults. These faults were also studied in the field as well as from aircraft and in aerial photography. The San Andreas/Banning and the Mission Creek faults can be traced across Coachella Valley even though they are buried by alluvium. The faults form ground water barriers and the near surface ground water on the northeast sides of the faults supports patches of vegetation (mesquite and palms) in an otherwise barren desert. These oases are best seen in band 3 (color IR). Otherwise, faults are best seen in band 4 (aerial color). Of the B and W bands, 5 (red) is best for delineating faults. Bands 1 and 2 are excessively grainy and the resolution is considerably inferior to the other bands.

Merifield, P. M.↗

NASA NTRS1974

Iron-absorption band analysis for the discrimination of iron-rich zones

The author has identified the following significant results. Most major rock units and unaltered and altered areas in the study area can be discriminated on the basis of visible and near-infrared spectral reflectivity differences recorded from satellite altitude. These subtle spectral differences are detectable by digital ratioing of the MSS bands and subsequent stretching to increase the contrast to enhance spectral differences. Hydrothermally altered areas appear as anomalous color patches within the volcanic-rock areas. A map has been prepared which can be regarded as an excellent reconnaissance exploration map, for use in targeting areas for more detailed geological, geochemical, and geophysical studies. Mafic and felsic rock types are easily discriminated on the color stretched-ratio composite. The ratioing process minimizes albedo effects, leaving only the recorded characteristic spectral response. The spectra of unaltered rocks appear different from those of altered rocks, which are typically dominated by limonite and clay minerals. It seems clear that differences in spectral shape can provide a basis for discrimination of geologic material, although the relations between visible and near-infrared spectral reflectivity and mineralogical composition are not yet entirely understood.

Rowan, L. C.↗

NASA NTRS1974

Evaluate ERTS imagery for mapping and detection of changes of snowcover on land and on glaciers

The author has identified the following significant results. Snowlines on a small drainage basin were accurately identified on bulk ERTS-1 images without use of digital processing, and results checked with high altitude and ground-based photography. The area and approximate shape of snow patches as small as 20,000 sq m could be correctly identified with a magnifying scanning densitometer. The resolution of ERTS is more than ample for most snow mapping needs. Mount Baker, Washington, has a large crater south of the summit and an area north of the summit which emit considerable geothermal heat in the form of fumaroles and hot ground. Temperatures are being monitored using an ERTS DCS. Debris flows are occassionally released from the crater due to water saturation at the base of a heavy snowpack lying on hydrothermally altered hot ground. These debris flows present a possible hazard to life and property, as they are discharged down the Boulder Glacier toward Baker Lake, the upper of two major hydroelectric power reservoirs which are situated above the populated Skagit River Valley. ERTS-1 images show that the most recent debris flow (20-21 August 1973) can be clearly discerned and mapped. ERTS images provide another important tool for monitoring this potential hazard.

Meier, M. F.↗

NASA NTRS1973

Observations of Mare Serenitatis from lunar orbit and their interpretation

Visual observations are investigated of color differences of Serenitatis mare materials from orbit complement photography and other remotely sensed data. The light tan gray inner fill of the Serenitatis basin is younger than the dark blue gray annulus; the latter continues into and appears to be contemporaneous with the fill of Mare Tranquillitatis. Mare ridges occur in both the inner basin fill and the dark annulus of Serenitatis. Ridges are interpreted as the result of structural deformation and up-doming after the solidification of the basaltic lavas. On the southeastern rim of the Serenitatis basin is the darkes blue gray unit within which Apollo 17 landed. Highland massifs surrounding this unit have unstable slopes which are believed to be the result of localized tectonic activity. On the southwest rim of the basin are the dark tan to brown gray mantling materials of the Sulpicius Gallus Formation. Farther west on the rim are dark blue grap patches which resemble the mare material of the Serenitatis dark annulus.

El-Baz, F.↗