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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Investigate optimum way of adding wideband capability and recommend a design for modification of one government furnished AM baseband demultiplexer, phase 1

The effort to analyze and test the Teledyne/Adcom model G-146 demultiplexer to determine the feasibility and optimum method(s) for modifying the unit for broadband operation is described. The desired bandwidths under consideration included 2, 4, and 8 kHz for double sideband and quadrature double sideband, and 4, 8, and 16 kHz for single sideband.

Source record↗
NASA NTRS1973

Feasibility of mining lunar resources for earth use: Circa 2000 AD. Volume 1: Summary

The feasibility of obtaining lunar minerals for terrestrial uses is examined. Preliminary results gave indications that it will not be economically feasible to mine, refine, and transport lunar materials to Earth for consumption. A broad systems approach was used to analyze the problem. It was determined that even though the procedure was not economically advisable, the concept for the operations is technically sound.

Nishioka, K.↗
NASA NTRS1976

AHIMSA - Ad hoc histogram information measure sensing algorithm for feature selection in the context of histogram inspired clustering techniques

An algorithm is proposed for dimensionality reduction in the context of clustering techniques based on histogram analysis. The approach is based on an evaluation of the hills and valleys in the unidimensional histograms along the different features and provides an economical means of assessing the significance of the features in a nonparametric unsupervised data environment. The method has relevance to remote sensing applications.

Dasarathy, B. V.↗
NASA NTRS1977

Noise adding radiometer improvement

Simple computer software modification compensates for nonideal detector characteristics to provide improved system performance.

Gardner, R. A.↗
NASA NTRS1978

Adding through-bolt holes to pin-fin cold plates

Spot-welding technique is less expensive than secondary-brazing and electron-beam methods. With procedure, standard plates can be modified in quantity for various mounting configurations without need for special tooling.

Ruppe, E. P.↗
NASA NTRS1976

Satellites for distress alerting and locating: Report by Interagency Committee for Search and Rescue Ad Hoc Working Group

The background behind the congressional legislation that led to the requirement for the Emergency Locator Transmitter (ELT) and the Emergency Position-Indicating Radio Beacon (EPIRB) to be installed on certain types of aircraft and inspected marine vessels respectively is discussed. The DAL problem is discussed for existing ELT and EPIRB equipped aircraft and ships. It is recognized that the DAL requirement for CONUS and Alaska and the maritime regions are not identical. In order to address the serious DAL problem which currently exists in CONUS and Alaska, a low orbiting satellite system evolves as the most viable and cost effective alternative that satisfies the overall SAR system design requirements. A satellite system designed to meet the needs of the maritime regions could be either low orbiting or geostationary. The conclusions drawn from this report support the recommendation to proceed with the implementation of a SAR orbiting satellite system.

Ehrlich, E.↗
NASA NTRS1978

The Ad Hoc Mars Airplane science working group

The capability of a remotely piloted airplane as a Mars exploration vehicle in the aerial survey mode is assessed. Specific experiment areas covered include: visual imaging; gamma ray and infrared reflectance spectroscopy; gravity field; magnetic field and electromagnetic sounding; and atmospheric composition and dynamics. It is concluded that (1) the most important use of a plane in the aerial survey mode would be in topical studies and returned sample site characterization; (2) the airplane offers the unique capability to do high resolution, oblique imaging, and repeated profile measurements in the atmospheric boundary layer; and (3) it offers the best platform from which to do electromagnetic sounding.

Clarke, V. C., Jr.↗
NASA NTRS1979

Report of the Ad Hoc Committee on the assessment of models of a wake shield environment around various spacecraft, Universities Space Research Association

Models depicting the ambient atmosphere which can overtake the spacecraft vacuum shield are presented. The subject areas discussed are: possible changing effects on the wake shield environment; possible utilization of the induced environmental contamination monitor; present state of the knowledge of the parameters used to describe the intermolecular collisions; the possibility of using simple models to describe the wake shield environment; possible errors associated with using kinetic theory to calculate that part of the atmosphere overtaking the shield; and a general assessment of the Monte Carlo techniques used to calculate the shield environment.

Wu, S. T.↗
NASA NTRS1980

An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen - Preliminary results

The influence of ground-based gas turbine combustor operating conditions and fuel-bound nitrogen (FBN) found in coal-derived liquid fuels on the formation of nitrogen oxides and carbon monoxide is investigated. Analytical predictions of NOx and CO concentrations are obtained for a two-stage, adiabatic, perfectly-stirred reactor operating on a propane-air mixture, with primary equivalence ratios from 0.5 to 1.7, secondary equivalence ratios of 0.5 or 0.7, primary stage residence times from 12 to 20 msec, secondary stage residence times of 1, 2 and 3 msec and fuel nitrogen contents of 0.5, 1.0 and 2.0 wt %. Minimum nitrogen oxide but maximum carbon monoxide formation is obtained at primary zone equivalence ratios between 1.4 and 1.5, with percentage conversion of FBN to NOx decreasing with increased fuel nitrogen content. Additional secondary dilution is observed to reduce final pollutant concentrations, with NOx concentration independent of secondary residence time and CO decreasing with secondary residence time; primary zone residence time is not observed to affect final NOx and CO concentrations significantly. Finally, comparison of computed results with experimental values shows a good semiquantitative agreement.

Bittker, D. A.↗