January 1998

A method of measuring the concentration of a selected organic compound (analyte) in a sample of water involves (1) producing hydrogen peroxide as a byproduct of enzyme-catalyzed...

Briefs: Electronics & Computers
Automated Seafloor Classification System (ASCS)

As the highest resolution seismic system available, the automated seafloor classification system (ASCS) can remotely and accurately map sediment properties for many seafloor applications. The...

Compact analog/digital electronic data processors of a novel type are based on the concept of the optimization cellular neural network (OCNN) and are implemented in...

Briefs: Electronics & Computers
Photoelectrochromic "Smart" Windows and Displays

Electrochromic devices change color and light transmissivity upon application of an electric charge. As such they should prove valuable as "smart" windows that can reduce air-conditioning...

Briefs: Electronics & Computers
Two-Wavelength Focal-Plane Array of QWIPs

A proposed focal-plane array (FPA) of quantum-well infrared photodetectors (QWIPs) would exhibit peak response at two wavelengths. Heretofore, single-focal-plane arrays of photodetectors optimized...

Briefs: Materials
Characterization of Woven-Carbon/Copper-Matrix Composites

Designing metal-matrix composites into actual components requires both experimental and analytical characterization of the behavior of these composites. This report describes mathematical modeling and experimental characterization of the elastoplastic behaviors of composite materials...

Briefs: Manufacturing & Prototyping
Rapid Prototyping of Cast Metal/Fiber Composites

A rapid prototyping process enables the incorporation of continuous fiber reinforcement into a cast metal-matrix composite. In one older process, cast metal-matrix composites are made by introducing fibers or particles into molten or partially solidified metals, then casting the resulting...

Briefs: Mechanical & Fluid Systems
Increased Life for Steel-Slitter Guide Rolls

There has been some success in continuing efforts to increase the service lifetimes of the guide rolls in hot-roll-slitter machines in the steel industry. In these machines, hardened knives are...

Kinetic rate data are needed to design all chemical processes. Specifically, they are needed to determine such things as ignition delay times, combustion times, and explosion...

Cross-diffraction gratings have been proposed to provide optical coupling to quantum-well infrared photodetectors (QWIPs) in focal-plane arrays (FPAs). The cross-grating coupling scheme...

Briefs: Software
ICAN/PART - Integrated Particulate Composite Analyzer

The Integrated Particulate Composite Analyzer (ICAN/PART) computer program is a modified version of the Integrated Composite Analyzer (ICAN) program (LEW-15592/LEW-15832), which was developed to conduct analyses of the micromechanics of fiber-reinforced polymer-matrix composite materials....

Briefs: Software
Web-Based Software for Coordinating Work

WWWorkflow is a language-driven, data-base-mediated, web-based process mediation system. WWWorkflow leverages on intranet applications and existing information infrastructure services, making it possible to add workflow management features to preexisting information management systems, without the need...

Briefs: Physical Sciences
Potential Commercial Applications From Microgravity Combustion Research

The paper entitled "Potential Commercial Applications From Combustion and Fire Research in Space" reviews the status of potential commercial applications derived from research on combustion in microgravity environments encountered in orbiting spacecraft. Such research...

Laser Doppler velocimetry (LDV) systems have been used for a number of years in field and laboratory applications. The normal LDV system consists of a two-color, four-beam...

Experiments have shown that nonreactive ion-beam sputtering can be used to deposit a transparent film of aluminum oxide on a polycarbonate, silicon, or fused-silica substrate....

Briefs: Physical Sciences
Proximity Measurement of Pressure and Temperature

Inexpensive, high-performance, optically coupled temperature and strain gauges based on a combination of advanced optoelectronic and microelectromechanical concepts have been proposed. The sensors would contain vibrating beams with submillimeter dimensions, made primarily of silicon by...

Weightless Environment Training Facility Inertial Training Spheres (WETFITSs) are proposed neutrally buoyant training tools that would be used in NASA's Weightless Environment...

Passivation by coating with OCG285 (or equivalent) polyimide at critical steps of fabrication has been found to enhance the quality of tapered edges in high-critical-temperature...

Briefs: Software
Virtual-Reality Platform-Independent Software for Access to Mars Data

The Virtual Reality Mars Atlas User Interface (VR-MAUI) provides an atlaslike interface for access to Mars data. This access is provided via the World Wide Web, using JAVA. Within VR-MAUI, images are organized as maps. These maps provide a natural coordinate system, which...

A newly developed instrument, designed at Marshall Space Flight Center, uses the resistance to alternating current running through a device to measure the variances in...

Briefs: Electronics & Computers
Reducing Surface Leakage Currents in FPAs of QWIPs

Chemical surface treatments during fabrication have been proposed to reduce surface leakage currents in focal-plane arrays (FPAs) of quantum-well infrared photodetectors (QWIPs). For reasons explained below, if most or all of the surface leakage currents could be eliminated by such treatments,...

Briefs: Electronics & Computers
Image-Matching System Highlights Changes in Skin Lesions

A video imaging and image-data-processing system for use in dermatological examinations acquires and processes images of patients' skins. The system processes a current image of a selected area of a patient's skin along with an image of the same area acquired previously, generating a...

Briefs: Physical Sciences
A Multicolor Imaging Pyrometer

Physical Sciences Inc. (PSI) designed, constructed, and delivered a prototype passive imaging pyrometer capable of accurately measuring and controlling the temperature distribution across a specified surface. The device was originally designed, under a NASA SBIR contract (solicitation year 1985) monitored by Jet...

PS300 is a self-lubricating solid coating material for use in sliding contacts at temperatures up to 800°C. PS300 is a composite of metal-bonded chromium oxide with barium...

An integrated thin-film device has been designed to constitute the sensory element of a miniature instrument for measuring the concentration of an atomic or molecular species that exhibits...

Briefs: Mechanical & Fluid Systems
Applying Controlled Pressure Distributions to Complex Curved Surfaces

A technique for applying controlled test pressures to curved surfaces is based on a principle similar to that of a compartmented pilot's or astronaut's pressure suit. The technique involves the use of airbags that accommodate geometric complexity in both the surface under...

Briefs: Mechanical & Fluid Systems
Equations for Failure Modes of Mechanical Systems

A report presents information compiled from a search of the literature on failure modes of mechanical systems. The report was written to provide a reference base for the application of first-order reliability methods to mechanical systems in the development of a system-level design methodology....

A diagnostic signal-analysis technique, called the Phase Synchronized Enhancement Method (PSEM), has been developed. This method allows NASA engineers to retrieve any unique...

Briefs: Manufacturing & Prototyping
Friction Stir Weld System for Welding and Weld Repair

A friction stir weld (FSW) system for welding and weld repair can be used on the manufacturing floor, as well as in the laboratory environment. This FSW system can be used in a wide...

Briefs: Information Technology
WAN DBMS Search Engine for Scientific Data Formats

A software interface between scientific data formats (SDF's) and wide-area data-base search-engine software has been developed to provide seamless access to data used in support of NASA projects. Most SDF's are known or understood by only a select audience. These SDF's are also only searchable...

Briefs: Mechanical & Fluid Systems
Improved Lifetime for Stirling Cryogenic Coolers

A Stirling cooler is a mechanical system that approximates the ideal gas cycle. Often associated with airborne or portable cooling applications that require compact design and low input power,...

Briefs: Physical Sciences
Adjacent-Pair Imaging Shearography Using Bacteriorhodopsin

In a developmental technique of real-time adjacent-pair imaging shearography, a thin film of bacteriorhodopsin is used to record shearograms in argon-laser light for immediate readout in helium/neon-laser light. Unlike conventional silver-halide-based photographic film, bacteriorhodopsin...

The figure illustrates a solar thermal energy system for boiling water or another liquid. The system can be used for a variety of purposes that can include drying aqueous hazardous...

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