Physical Sciences

A report describes the use of advanced electromagnetic probes to measure the dimensions, the spatial distribution of electrical conductivity, and related other properties of friction stir welds (FSWs) between parts made of the same or different aluminum alloy(s). The probes are of the...

A report describes the development of the spaceborne infrared atmospheric sounder (SIRAS)—a spectral imaging instrument, suitable for observing the atmosphere of the Earth from a spacecraft, that utilizes four spectrometers to cover the wavelength range of 12 to 15.4 µm with a spectral resolution that...

A method of reducing errors in noisy magnetic-field measurements involves exploitation of redundancy in the readings of multiple magnetometers in a cluster. By "redundancy" his meant that the readings are not entirely independent of each other because the relationships among the...

A coarse-positioning instrument is built around a three-axis magnetometer. The magnetometer is of a type that is made of inexpensive hardware and is suitable for use aboard spacecraft orbiting no more than 1,000 km above the surface of the Earth. A data processor programmed with suitable...

Tubes made from biaxially oriented liquid-crystal polymers (LCPs) have been developed for use as penetrations on cryogenic tanks. ("Penetrations" in this context denotes feed lines, vent lines, and sensor tubes, all of which contribute to the undesired conduction of heat into the tanks.)...

This second of three reports on a computational study of a mixing layer laden with evaporating liquid drops presents the evaluation of Large Eddy Simulation (LES) models.

SmaggIce version 1.2 is a computer program for preparing and analyzing iced airfoils.It includes interactive tools for measuring ice-shape characteristics, controlled smoothing of ice shapes, curve discretization, generation of artificial ice shapes,and detection and correction of input errors.

A theoretical and experimental investigation has shown that the capacities of heat pipes can be increased through suitable reformulation of their working fluids. The surface tensions of all of the working fluids heretofore used in heat pipes decrease with temperature. As explained in more...

A method of rapid, programmable filtering of spectral transmittance, reflectance, or fluorescence data to measure the concentrations of chemical species has been proposed. By "programmable" is meant that a variety of spectral analyses can readily be performed and modified in software, firmware,...

This first of three reports on a computational study of a drop-laden temporal mixing layer presents the results of direct numerical simulations (DNS) of well-resolved flow fields and the derivation of the large-eddy simulation (LES) equations that would govern the larger scales of a...

Three papers present studies of thermal balances, dynamics, and electromagnetic spectra of protoplanetary disks, which comprise gas and dust orbiting young stars. One paper addresses the reprocessing, in a disk, of photons that originate in the disk itself in addition to photons that originate in the stellar...

Compact optical oxygen sensors with self-calibration capabilities are undergoing development. A sensor of this type features a single-chip, integrated-optic design implemented by photolithographic fabrication of optical waveguides in a photosensitive porous glass. The porosity serves as both a matrix for retention of...

Hybrid piezoelectric/fiber-optic (HyPFO) sensor sheets are undergoing development. They are intended for use in nondestructive evaluation and long-term monitoring of the integrity of diverse structures, including aerospace, aeronautical, automotive, and large stationary ones. It is anticipated that the...