Physical Sciences

A report describes an investigation of the validity of using statistical methods based on single-point probability density functions (PDFs) in mathematical modeling of mixing between a turbulently flowing carrier gas and the vapor from liquid drops suspended in the gas. The...

"Pushbroom" imaging spectrometers of a proposed type would exhibit little or no distortion in either the spectral or spatial direction. These spectrometers would feature modified Offner optics, which afford a desirable combination of compactness and a high degree of optical correction. Although Offner optics...

Variable-thermal-conduction devices containing shape-memory-alloy (SMA) actuators have been proposed for use in situations in which it is desired to switch on (or increase) thermal conduction when temperatures rise above specified values and to switch off (or decrease) thermal conduction when...

Gauges that would measure liquid levels optically have been proposed for use in aircraft fuel tanks. These gauges would contain no moving parts (no floats) and no wiring inside the tanks. Their overall function could be characterized as that of permanently immersed, self-reading dipsticks.

A report discusses experiments on the flow of water along the interior of a transparent rotating cylindrical drum, the interior of which was partitioned into five cavities by disks with central holes and outer edges attached to the cylindrical drum wall. This water-flow model was designed to provide...

A proposed technique would make it possible to maintain two reservoirs of superfluid helium at the same pressure but at different temperatures. Heretofore, a fountain effect (described below) has made this impossible. The proposed technique could be useful for low-temperature...

A method of in situ chemical analysis by use of small, simple, robust sensors has been proposed. The basis for the proposal is the discovery that chemical reactions emit acoustic waves, and that characteristic frequency spectra are associated with specific reactions. The acoustic frequencies...

A report describes an experimental study of whether an advanced fiber-optic dynamic-light-scattering (DLS) probe affords a capability for noncontact detection of particles of various sizes associated with the stages of growth of protein crystals in automated hanging-drop protein-growth...

An improved design for a biplate in a methanol fuel cell provides increased efficiency in the removal of water, relative to older designs. For reasons explained below, this design both improves the performance of the fuel cell and increases the overall energy efficiency of the...

An instrumentation system monitors rates of leakage of hydrogen from multiple zones on a complexly shaped tank. Each zone is established by bagging a designated exterior portion of the tank. The bag for each zone is purged with a carrier gas (either nitrogen or helium) at a controlled flow...

Transparent furnaces are being developed for use in research on properties and processing of materials at high temperatures. Full optical access to the interiors of furnaces is intended to provide the capability for nonintrusive diagnosis and feedback control of the subtleties of high-temperature...