Tech Briefs

A comprehensive library of technical briefs from engineering experts at NASA and major government, university, and commercial laboratories covering all aspects of innovations in electronics, software, photonics, imaging, motion control, automation, sensors, test, materials, manufacturing, mechanical, and mechatronics.

Briefs : Electronics & Computers
Fabricating Diffusion-Cooled Hot-Electron-Bolometer Elements

Microbridges that constitute the superconducting-transition sensory elements of electron-diffusion-cooled hot-electron bolometers can now be fabricated in increased yield and quality. This improvement is made possible by a fabrication process that notably includes the use of a...

Briefs : Software
Software for Processing SAR Images of the Polar Oceans

The RADARSAT/ERS-1,2 Geophysical Processor System (RGPS) is an automated system of hardware and software that processes synthetic-aperture-radar (SAR) images of ice and open water in polar oceans to generate higher-level geophysical-data products. Information in such products includes the...

Briefs : Information Technology
Diagnosing Helicopter Gearboxes Using Connectionist Networks

A method of automated diagnosis of helicopter gearboxes involves processing of selected features of digitized outputs of vibration sensors via structure-based connectionist networks (SBCNs), which are mathematical constructs that incorporate elements from the disciplines of dynamical...

Briefs : Software
Software for Development of Spacecraft-Simulation Programs

DARTS Shell (Dshell) is a multimission spacecraft simulator for the development, integration, and test of flight software and hardware. Dshell reduces the time and cost of developing simulation programs by enabling the development of the software in modular, reusable form and by...

Briefs : Physical Sciences
Mass Analyzer With Rotating Electric Fields

A device for measuring the distribution of masses in an atmosphere or plasma exploits the electrostatic deflection of ions in a rotating magnetic field. A magnetic field is not required. The device is simple to construct, can be made small, and is amenable to micromachining techniques such as LIGA...

Briefs : Photonics/Optics
Program for Analysis of a Complex Optomechanical System

The IMOS computer program contains subprograms that, collectively, provide a unique capability for multidisciplinary analysis of a system represented by a combination of mathematical models of structural (mechanical), control, thermal, and optical characteristics. One example of such a...

Briefs : Electronics & Computers
Algorithm Estimates Doppler Shift in a Received DPSK Signal

An algorithm estimates the Doppler frequency shift in a received radio signal with square-wave-pulse binary differential-phase-shift-keyed (DPSK) modulation. [With little modification, the algorithm is also extensible to M-ary (where M is an integer > 2) DPSK modulation with pulse...

Briefs : Software
Software for Tracking the Performance of Other Software

The Flight Software Memory Tracker (FMT) computer program is a collection of utility subprograms developed for use on the ground to track images of the flight software (FSW) in the computers aboard the Cassini spacecraft. [As used here, "images" signifies both (1) the memory load and...

Briefs : Physical Sciences
Production of Tar in Pyrolysis of Large Biomass Particles

A paper presents a study of the production of tar in the pyrolysis of spherical biomass particles, with computational simulations performed by using the macroparticle portion of the model described in "Generalized Mathematical Model of Pyrolysis of Plant Biomass" (NPO-20068) elsewhere...

Briefs : Materials
Phospha-s-Triazines and Other Compounds for Use as Additives

A report describes research on selected compounds as additives to perfluoroalkyether (PFPAE) fluids that are used as synthetic lubricants for metal parts. Additives are needed to inhibit both thermo-oxidative degradation of, and corrosion of metals by, the PFPAE fluids in the presence...

Briefs : Photonics/Optics
Thermal Lens Spectrometer Yields High Sensitivity

Thermal lens spectrometry is a highly sensitive method for detecting very small quantities of material by the absorption of light from a laser source. It takes advantage of the thermal lens effect to measure the absorption spectrum of a sample. This invention utilizes an optical parametric...

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...

Technology Leaders