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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 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Electrical indication of airflow rate

Adaption of gas-flow measurement technique originally developed by C. C. Thomas in 1911 is used for temperature measurements which are easily converted to electrical signals.

Murrish, C.↗
NASA NTRS1979

Volume-change indicator for molding plastic

Monitor consisting of two concentric disks measures change in volume of charge during compression/displacement molding. Device enables operator to decide whether process pressure and temperature are set properly or whether sufficient material has been placed in mold.

Heler, W. C.↗
NASA NTRS1978

On the determination and investigation of the terrestrial ionospheric refractive indices using GEOS-3/ATS-6 satellite-to-satellite tracking data

When the radio link between two satellites (GEOS-3/ATS-6) is intercepted by the earth's ionosphere and neutral atmosphere, a change in the Doppler frequency results. Travel through the atmosphere causes the Doppler phase to be advanced in the ionosphere's portion and retarded in the neutral portion of the atmosphere. Analysis of the shortening and lengthening of the phase of the Satellite-to-Satellite Tracking (SST) data that passed within 40-700 km above the earth's surface during its ATS-6 to GEOS-3 to ATS-6 path, caused by the atmosphere, results in refractivity versus height profiles. The SST Doppler data were used directly to adjust the GEOS-3 orbit. Perturbation from the Moon, Sun and a 15th order/degree earth gravity field were included in the orbit solution. This orbit was continued through the occultation period and a model ionosphere was estimated by a least-square adjustment of the Chapman ionosphere parameters from the SST data residuals. The refractivity profile obtained by this model ionosphere was compared to a refractivity profile obtained by a direct integral inversion of the SST data residuals. Systematic differences between the 2 methods were caused by orbital errors, which propagated into the solution. The SST data yielded refractive index profiles in a novel economical manner because no additional or special on-board equipment were required.

Liu, A. S.↗
NASA NTRS1979

Late diagenetic indicators of buried oil and gas. 2: Direct detection experiment at Cement and Garza fields, Oklahoma and Texas, using enhanced LANDSAT 1 and 2 images

The author has identified the following significant results. The Cement oil field, Oklahoma, was a test site for an experiment designed to evaluate LANDSAT's capability to detect an alteration zone in surface rocks caused by hydrocarbon microseepage. Loss of iron and impregnation of sandstone by carbonate cements and replacement of gypsum by calcite were the major alteration phenomena at Cement. The bedrock alterations were partially masked by unaltered overlying beds, thick soils, and dense natural and cultivated vegetation. Interpreters, biased by detailed ground truth, were able to map the alteration zone subjectively using a magnified, filtered, and sinusoidally stretched LANDSAT composite image; other interpreters, unbiased by ground truth data, could not duplicate that interpretation.

Donovan, T. J.↗
NASA NTRS1979

Lightning as an indication of storm severity

There is a substantial case for the theory that cloud electrification is related primarily to strong convection and the sizeable relative air motion that it implies; therefore, the electrification and subsequent discharge rates can be related to the air motion environment of thunderstorms. The isoceraunic contour map used by the WMO for observing and measuring thunderstorm occurrence contains no information on flash rates, flash density, flash relationship to storm severity, or flash variation with meteorological environment. A constant-view geosynchronous lightning mapper would permit simultaneous studies of the lightning discharge patterns and the meteorological environment of storms, thus establishing whether or not there is a reliable enough relationship to use the observed flash rates and characteristics as supplemental guidance for storm forecast refinement.

Dodge, J. C.↗
NASA NTRS1981

Bulk lifetime indicates surface contamination

Indirect measurement of wafer surface impurities has sensitivity of 300 monolayers. Photoconductivity-decay apparatus determines bulk recombination lifetime in semiconductor materials. Bulk impurity levels before and after annealing relate to level of surface contamination. Method evaluates wafer cleaning techniques, qualifying purity of chemical and deionized water used, or monitors production process.

Blais, P. D.↗
NASA NTRS1979

Review of selected geomagnetic activity indices

Magnetic activity indexes are reviewed. Classifications of magnetograms from single observatories and the global range of potential associated with the equivalent currents which could have produced the variations monitored at a large array of recording sides are addressed. Principal magnetic activity indexes discussed include: the auroral electrojet index and its associated indexes (AU, AL and AO) useful for auroral zone studies; the Kp, ap, aa and am indexes which are measures of midlatitude geomagnetic activity; and the Dst index of magnetic activity recorded at low latitudes. It is concluded that geomagnetic activity indexes are useful in studies of the interaction between solar activity, the interplanetary magnetic field and solar wind, the magnetosphere, ring current, field aligned currents, and ionospheric currents.

Allen, J. H.↗
NASA NTRS1980

The dynamics of certain indicators of nuclein metabolism during hypokinesia in rats of different ages under the influence of sinusoidal modulated currents and measured physical load

The influence of sinusoidal modulated currents was studied and physical loads on the nucleic acid content and the nucleotide composition of the total RNA in muscles of rats of various ages under conditions of hypodynamia were measured. Methodology utilized is described and conclusions are presented.

Sokolova, Z. A.↗
NASA NTRS1980

Two-photon excitation of nitric oxide fluorescence as a temperature indicator in unsteady gas-dynamic processes

A laser induced fluorescence technique, suitable for measuring fluctuating temperatures in cold turbulent flows containing very low concentrations of nitric oxide is described. Temperatures below 300 K may be resolved with signal to noise ratios greater than 50 to 1 using high peak power, tunable dye lasers. The method relies on the two photon excitation of selected ro-vibronic transitions. The analysis includes the effects of fluorescence quenching and shows the technique to be effective at all densities below ambient. Signal to noise ratio estimates are based on a preliminary measurement of the two photon absorptivity for a selected rotational transition in the NO gamma (0,0) band.

Mckenzie, R. L.↗
NASA NTRS1979

Partitioning as a cooling rate indicator

The paper presents a mathematical model for describing solute partitioning under continuous cooling conditions. It is shown that solute concentration profiles can be calculated for any cooling rate as a function of temperature provided that the appropriate data on diffusion and partitioning are known. As an example, the model is applied to zirconium partitioning between ilmenite and ulvospinel in a number of Apollo 15 Elbow Crater rocks in order to estimate the rates at which they cooled.

Onorato, P. I.↗
NASA NTRS1980

ISEE 1 charged particle observations indicative of open magnetospheric field lines near the subsolar region

On November 20, 1977, at 0230-0300 UT, ISEE 1 encountered unusual charged particle distributions within the magnetosphere. The three-dimensional distribution observations for energetic (greater than 24 keV) ions and plasma show the development of field-aligned asymmetries in the energetic ion distributions simultaneously with a marked change in plasma flow. It is concluded that the most likely explanation for these observations is that ISEE 1 encountered open magnetospheric field lines at its position within the magnetosphere (1030 LT and 1200 plus or minus 300 km from the magnetopause). Field lines were open near the geomagnetic equator, and the geometry was spatially or temporally variable. Other features of the field line topology are presented.

Williams, D. J.↗
NASA NTRS1982

Acoustic Emissions Could Indicate Weld Quality

Preliminary tests show quality of welds can be assessed by acoustic-emission monitor mounted on welder. Nondestructive measurement technique allows operator to determine uniformity and integrity of weld as being made, evaluate equipment performance and condition, and initiate corrective action if quality is not satisfactory.

Gustafson, P. E.↗