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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Glass encapsulation provides extra protection for IC semiconductor devices

Oxide-passivated semiconductor chip is given protective glass coating by means of vapor deposition over metallic substrate of integrated circuit (IC). Method provides more reliable oxide-passivation and hermetic sealing in current use. Chips and scratches incurred during dicing, testing, and assembly are markedly reduced.

Doelp, W. L., Jr.↗
NASA NTRS1974

Theoretical investigation of isotopic anomaly of xenon in carbonaceous chondrites and other terrestrial and extra-terrestrial samples

The composition of Xe released from carbonaceous chondrites between 600 and 1000 C, particularly its isotopic trapped forms, is analyzed. Data show trapped Xe to have the following forms: Xe-124, 126, 130, 131, 132, 134, and 136. Attempts were also made to explain the Xe anomaly by mass fractionation as well as determine the relationship between metoritic trapped Xe and solar Xe.

Sabu, D. D.↗
NASA NTRS1972

Effects of geophysical extra-terrestrial and terrestrial physical stimuli on living organisms - Effects of gravity fields on living organisms

The biologic effects of greatly reduced gravity resulting from space flight are examined. Aspects of U.S. space biology during the period from 1960 to 1972 are discussed, giving attention to the Discoverer satellites, the Gemini series, the OV1-4 satellite, the biosatellite project, the orbiting frog otolith experiment, and the Apollo program. Other studies considered are related to the effects of galactic particles on nonproliferating cells, a recoverable tissue culture experiment, cell cycle maintenance in human lung cells, and effects of space flight on circadian rhythms. Viking will land on the planet Mars in 1975 in search for life forms.

Saunders, R. J. F.↗
NASA NTRS1976

Study of the extra-ionic electron distributions in semi-metallic structures by nuclear quadrupole resonance techniques

A straightforward self-consistent method was developed to estimate solid state electrostatic potentials, fields and field gradients in ionic solids. The method is a direct practical application of basic electrostatics to solid state and also helps in the understanding of the principles of crystal structure. The necessary mathematical equations, derived from first principles, were presented and the systematic computational procedure developed to arrive at the solid state electrostatic field gradients values was given.

Murty, A. N.↗
NASA NTRS1977

Development of an extra-high strength powder metallurgy nickel-base superalloy

A program was conducted to optimize the composition of NASA IIb-11, an alloy originally developed as a wrought material, for thermal stability and to determine the feasibility for producing the alloy using powder metallurgy techniques. Seven compositions were melted and atomized, hot isostatically pressed, cross rolled to disks and heat treated. Tensile and stress rupture properties from room temperature to 870 C (1600 F) were determined in addition to thermal stability characteristics. Processing variables included hot isostatic pressing parameters and handling, cross rolling procedures and heat treatment cycles. NASA IIb-11E displayed the best combination of overall properties for service as a 760 C (1400 F) disk material. Its composition is 0.06 C, 8.5 Cr, 9.0 Co, 2.0 Mo, 7.1 W, 6.6 Ta, 4.5 Al, 0.75 Ti, 0.5 V, 0.7 Hf, 0.01 B, 0.05 Zr and balance Ni. While the alloy exhibits the highest 760 C (1400 F) rupture strength reported for any powder metallurgy disk alloy to date, additional studies to further evaluate the effects of heat treatment may be required. The alloy is not susceptible to topologically close-packed phase formation during thermal exposure at 870 C (1600 F) for 1,500 hours, but its mechanical property levels are lowered due to grain boundary carbide formation.

Kent, W. B.↗
NASA NTRS1977

A theoretical investigation of isotopic anomalies of xenon in terrestrial and extra-terrestrial samples

The abundance and isotopic composition of noble gases in meteorites is discussed in relation to the composition of the early solar system. Carbonaceous chondrites contain a unique Xenon-X, which is rich in heavy and light isotopes. Variations in the occurrence of type-X and type-Y (the normal component) noble gases are of such magnitude that neither the injection of material from a nearby supernova nor presence of presolar grains can account for the anomalies in meteorites. Therefore, it is suggested that the entire solar system may have condensed from the debris of a single local supernova.

Sabu, D. D.↗
NASA NTRS1978

Direct imaging of extra-solar planets with stationary occultations viewed by a space telescope

The use of a telescope in space to detect planets outside the solar system by means of imaging at optical wavelengths is discussed. If the 'black' limb of the moon is utilized as an occulting edge, a hypothetical Jupiter-Sun system could be detected at a distance as great as 10 pc, and a signal-to-noise ratio of 9 could be achieved in less than 20 min with a 2.4 m telescope in space. An orbit for the telescope is proposed; this orbit could achieve a stationary lunar occultation of any star for a period of nearly two hours.

Elliot, J. L.↗
NASA NTRS1979

Extra-safe tractor-trailer coupling

Built-in safety mechanism for tractor-trailer "fifth-wheel" coupling keeps rig together in case kingpin failure. Modified coupling utilizes all standard components, such as two wear plates, kingpin, and kingpin latch. It is modified by adding semicircular lip to top wear plate, matching semicircular slot to bottom wear plate, and two latching stop mechanisms.

Albrecht, W. P.↗
NASA NTRS1979

Extra-strong "floating nut"

Increased bearing area withstands much higher torque than previous designs. Floating nut makes it possible to fasten parts on heavy-duty equipment, such as tractors and cranes, even though they can be reached for tightening from one side only.

Charles, J. F.↗
NASA NTRS1979

First spectrum of an extra-solar object in the extreme ultraviolet The white dwarf HZ 43

An EUV instrument is described which has been used to carry out a spectroscopic observation of the hot white dwarf HZ 43. The instrument consists of an EUV telescope and spectrometer housed in a sounding-rocket shell 44 cm in diameter and 176 cm in length. It is noted that HZ 43 was successfully observed for 200 sec and that the EUV spectrum was strongly detected from 170 to 400 A. A second-order image was detected beyond 400 A, and a decrement was observed at 200 A, which corresponds to photoelectric absorption of He II. The observed spectrum is shown to be inconsistent with a coronal model. It is concluded that the surface number density of helium relative to hydrogen must be in the range from 0.00001 to 0.0001 and that an upper limit of 4 x 10 to the 17th per sq cm can be placed on the column density of ionized helium in the intervening interstellar medium.

Malina, R. F.↗
NASA NTRS1979

Systems level feasibility study for the detection of extra-solar planets. Volume 1: Infrared interferometer (IRIS) known as the Stanford Concept

A sensor system for the direct detection of extrasolar planets from an Earth orbit is evaluated: a spinning, infrared interferometer (IRIS). It is shuttle deployed, free flying, requires no on-orbit assembly and no reservicing over a design life of five years. The sensor concept and the mission objectives are reviewed, and the performance characteristics of a baseline sensor for standard observation conditions are derived. A baseline sensor design is given and the enabling technology discussed. Cost and weight estimates are performed; and a schedule for an IRIS program including technology development and assessment of risk are given. Finally, the sensor is compared with the apodized visual telescope sensor (APOTS) proposed for the same mission. The major conclusions are: that with moderate to strong technology advances, particularly in the fields of long life cryogenics, dynamical control, mirror manufacturing, and optical alignment, the detection of a Jupiter like planet around a Sunlike star at a distance of 30 light years is feasible, with a 3 meter aperture and an observation time of 1 hour. By contrast, major and possibly unlikely breakthroughs in mirror technology are required for APOTS to match this performance.

Source record↗
NASA NTRS1982

Extra-solar astronomy with a 2.4 m normal incidence X-ray telescope at 0.1 arcsec resolution

The advantages and disadvantages for astrophysical observations of a normal incidence X-ray telescope are considered. The baseline configuration is for a 2.4 meter diameter mirror operating at 0.23-0.28 keV with a CCD detector having a pixel size equivalent to 0.1 arcsec. This resolution enables X-ray images to be made comparable to those of Space Telescope in the optical and to those of the Very Large Array in the radio for a large number of sources. Specific examples cover essentially the entire range of astrophysics.

Elvis, M.↗
NASA NTRS1984

Some properties of transient phenomena in the extra-tropical region and their importance in the seasonal mean flow

When studying data for one season, it is convenient to divide transient eddies into those of the synoptic time scale and those of lower frequency. Where the dividing line is placed is not crucial, but a 10-day period is used in a study of the 1979-1980 Northern Hemisphere winter. The synoptic time scale eddies exhibit maximum kinetic energy in stormtracks slightly downstream from and poleward of the Atlantic and Pacific jet maximum. An alternative approach is via the anisotropic part of the horizontal velocity correlation tensor, the axis of which gives the local orientation of the eddies and the magnitude a measure of the extension of the eddies. When the man velocity field is almost that of the plane waves, the horizontal group velocity relative to the mean field is also related to this tensor. The synoptic time scale eddies force the mean flow in the sense of reducing the baroclinic component in the upstream of the region of the stormtrack. The lower frequency eddies have a very different signature.

Hoskins, B. J.↗