Physical Sciences

A report presents a computational study of heat and mass transfer for isolated and interacting drops of one fluid (liquid O2) immersed in another fluid (H2) in finite, quiescent surroundings under supercritical conditions. The mathematical models used in this...

Two reports describe a Rayleigh-scattering attitude sensor (RSAS) - an optoelectronic instrument for determining the orientation of a spacecraft. An RSAS comprises a telescope/video-camera/image-digitizer combination that is mounted on the spacecraft and that captures images of the limb of...

A report describes experiments in which planar laser-induced fluorescence (PLIF) of hydroxyl radicals was used to study the structures of flames in burner test rigs (a flame-tube combustor and a sector combustor) under conditions like those in combustors of aviation gas-turbine engines. The PLIF...

A report describes an experimental study of the low-temperature electrical characteristics of commercial Li/MnO2, Li/CFx, Li/SO2, Li/SOCl2, and Li/BCX primary electrochemical cells. These high-energy-density cells are under consideration for use as lightweight, compact electric-power sources...

Scientists at White Sands Test Facility (WSTF) have devised a kit for extracting nitrosamines from aqueous solutions. In comparison with extractions according to the method recommended by the Environmental Protection Agency (EPA), extractions by use of the kit are faster, cheaper and less...

Improved membrane/electrode assemblies (MEAs) made partly from hydrogen form of sulfonated polyether sulfone (HSPES) have been developed for use in methanol fuel cells. In comparison with traditional fuel-cell MEAs made partly from a commercial perfluorosulfonic acid-based polymer, these MEAs...

Experiments have demonstrated the feasibility of heat exchangers with flow channels containing open-cell metallic foams. Nonmetallic foams could also be used. One proposed design calls for an open-cell foam in the annular region between an inner and an outer tube, with a heat-transfer fluid flowing along the annular region...

A report comprising the main contents of U. S. Patent 5,750,895 presents detailed information on the subject of "Apparatus for Advanced Ultrasonic C-Scan Imaging (GSC-13524), NASA Tech Briefs, Vol. 21, No. 4 (April 1997), page 34. The apparatus is a computer-controlled ultrasonic C-scan...

In a proposed modification of the basic design of a Michelson interferometer, the beam aperture would be split into a number (N ≧ 2) of smaller areas and the optics arranged so that the beam in each area would generate a distinct segment of the overall desired interferogram. Each segment of the...