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A report discusses direct numerical simulations (DNS) of a developing mixing layer between nitrogen and heptane initially at different temperatures and initially flowing at different velocities under supercritical conditions. The usual conservation equations for a binary fluid, along with the...

A continuing program of research and development focuses on engineering of functional cartilage and cardiac muscle for scientific research and for eventual use in transplants. The program involves the use of cells, polymer scaffolds, and bioreactor vessels. A polymer scaffold serves as a three-dimensional structure...

The feasibility of a capacitive sensor for measuring the level of liquid nitrogen in a container has been demonstrated. The basic sensor design could also readily be adapted to measurement of the levels of cryogenic liquids other than nitrogen.

A mathematical model has been formulated to describe the pyrolysis of biomass in a bubbling fluidized-bed reactor. The reactor is a vertical cylinder that contains a mixture of biomass particles and sand. Superheated steam enters the reactor through holes in the bottom and flows out freely at...

A system that samples gases at multiple remote locations and delivers the gases to two or possibly more gas-monitoring instruments (e.g., mass spectrometers) has been developed. The system includes a transport (suction) pump that draws the gases from the sampling locations, through transport...

"S+Wavelets" is the name of a computer program that implements a suite of mathematical "tools" for wavelet analysis of signals (including two-dimensional signals that represent images.) Wavelets, being localized in both time and frequency (or space and wave number), serve as means for transforming and extracting...

A technique for assessing changes in the densities and compositions of communities of microorganisms in environmental samples is based partly on redox chemistry. Suspensions of microbes from environmental samples are inoculated into 95-well microtiter plates. Each well contains an initially...

A technique for extracting samples of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) for use in diagnosing and studying infectious and genetic diseases has been developed. The technique enables the concentration and purification of nucleic acids from large (in comparison with older...

A report proposes ultralight balloon systems to carry a 10-kg payload, including scientific instruments for exploring the atmospheres of Uranus and Neptune. The system masses to be transported to those planets would be kept low by not transporting balloon-inflating gases. Each system...

Version 5.0 of the Integrated Modeling of Optical Systems (IMOS) software has been released. A previous version was described in "Software for Multidisciplinary Analysis of Optical Systems" (NPO-20536), NASA Tech Briefs, Vol. 24, No. 11 (November 2000), page 36. In both versions, IMOS is...

A report proposes an apparatus that would extract water from the atmosphere of Mars and would consume little energy in doing so. The apparatus would include a set of copper plates surrounded by a thermal shield with slots through which atmospheric gas could circulate. At night, the slots...