January 1998

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...

Briefs : Physical Sciences
Black-Body Evaporator Unit for a Point-Focus Solar Collector

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 waste, distilling pure solvent from spent solvent, purifying water by distillation, or generating steam....

Briefs : Medical
Chemiluminescent Quantitation of Organic Compounds in Water

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 oxidation of the analyte, (2) producing light in an electrocatalyzed reaction of the hydrogen peroxide with...

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 costs by being darkened to absorb sunlight and reject unwanted solar heat. The biggest drawback is the cost of...

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, Stirling coolers are suitable for such applications because of their high efficiency. Compared to...

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 ASCS can accurately predict, in near-real time, sediment type and a number of selected geotechnical...

Briefs : Electronics & Computers
VLSI Neural Processors Based on Optimization Neural Networks

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 very-large-scale integrated (VLSI) circuitry. These VLSI neural processors are being developed to perform a variety of...

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 for two or more wavelengths have not been available. This FPA is intended to be a prototype of...

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 used to slice sheets of steel from large steel coils. The sheets are up to 0.375 in. (9.525 mm) thick and...

Briefs : Physical Sciences
Calculating Chemical-Reaction Rates From Thermodynamic Data

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 limits in engine combustors. Previously, chemical kinetic rate data have been determined experimentally by use...

Briefs : Electronics & Computers
Cross-Grating Coupling for Focal-Plane Arrays of QWIPs

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 is intended to enhance optical coupling (and thus increase quantum efficiency) within narrow spectral...

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...

Briefs : Electronics & Computers
A Laser Doppler Velocimetry (LDV) System for Fish Bypass Evaluation

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 system for obtaining two-component velocity measurements. These systems perform well in open flow but are...

Briefs : Materials
Sputter Deposition of Pure and Fluoropolymer-Filled Al₂O₃

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. Similar experiments have shown that reactive ion-beam sputtering can be used to form a transparent film of...

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...

Briefs : Mechanical & Fluid Systems
Fixtured Spheres for Training in Simulated Weightlessness

Weightless Environment Training Facility Inertial Training Spheres (WETFITSs) are proposed neutrally buoyant training tools that would be used in NASA's Weightless Environment Training Facility (WETF), where astronauts are trained underwater to manipulate objects in zero gravitation....

Briefs : Electronics & Computers
Polyimide Passivation for Making High-Tc Josephson Junctions

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 (high-Tc) superconductor/normal-conductor/superconductor (SNS) Josephson junctions. In...

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...

Briefs : Electronics & Computers
Signal-Conditioning Electronics for Discrete Capacitive Sensors

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 capacitance. Engineers use this device to detect the presence or absence of dielectric material between the plates...

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...

Briefs : Materials
Self-Lubricating Composite Coating for High-Temperature Use

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 fluoride/calcium fluoride eutectic and silver as solid lubricant additives. The "PS" in the name of this and...

Briefs : Physical Sciences
Integrated Thin-Film Fluorescence Sensor

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 fluorescence at specified excitation and emission wavelengths. The device combines a fluorescence-emission method...

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....

Briefs : Electronics & Computers
Phase-Synchronized Enhancement Method for Engine Diagnostics

A diagnostic signal-analysis technique, called the Phase Synchronized Enhancement Method (PSEM), has been developed. This method allows NASA engineers to retrieve any unique defect signatures and trends associated with different failure modes and unusual phenomena experienced during...

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 variety of welding and weld repair applications. It is capable of handling up to 6,000 pounds (26.7 kN) of...

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...

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