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 : Physical Sciences
Computer-Controlled Instrumentation Measures Hydrogen Leaks

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...

Briefs : Electronics & Computers
Optoelectronic Generation of Optical and Microwave Signals

The figure schematically illustrates an optoelectronic apparatus that generates both an optical output and an electronic output (typically at frequencies in the range from hundreds of megahertz to tens of gigahertz). The apparatus is denoted a "coupled opto-electronic oscillator" (COEO)...

Briefs : Mechanical & Fluid Systems
Program Facilitates Simulation of Flows of Cryogenic Fluids

EASY/ROCETS is a developmental computer program for mathematical modeling and analysis of dynamic flows of cryogenic fluids in a rocket-engine-testing facility. Heretofore, the numerical simulation of such flows has been accomplished by use of computer codes specific to test-equipment...

Briefs : Physical Sciences
Using CT Data in Finite-Element Models of MMC Components

X-ray-based Computed Tomography (CT) has been linked with finite-element analysis to provide a capability for structural characterization of as-manufactured parts— especially for the nondestructive evaluation of metal-matrix composite (MMC) material parts. In some cases, this capability...

Briefs : Information Technology
Robust Aeroservoelastic-Stability Margins

In aeroservoelastic (ASE)-stability analysis, one considers the coupling of the aerodynamic, inertial, structural, actuation, and control-system elements of the dynamics of an aircraft. The closed-loop interactions of these elements can introduce unexpected instabilities in flight if the analytical model...

Briefs : Electronics & Computers
Ultrathin Packaging of Multiple Integrated-Circuit Chips

A process being developed for ultrathin packaging of multiple integrated-circuit chips and associated microelectromechanical components makes it possible to fabricate a minimally invasive pressure-measuring instrument to be used in characterizing a boundary-layer flow inside a...

Briefs : Physical Sciences
Remote In-Flight Infrared Imaging for Analyzing Surface Flows

The feasibility of remotely acquiring infrared images (thermograms) of aircraft surfaces in flight to locate flow-transition boundaries has been investigated. As used here, "remotely" means that the infrared instrumentation is mounted aboard an observing aircraft that flies along with...

Briefs : Electronics & Computers
Fabrication of Thinned QWIP Arrays for Improved Performance

Focal-plane-array (FPA) hybrids of quantum-well infrared photodetectors (QWIPs) thinned to the membrane level are undergoing development. The developmental QWIPs in question are of the kind that exploit bound-to-quasi-bound absorption, as described, for example, in "Bound-to-Quasi-Bound...

Briefs : Electronics & Computers
Engine Monitoring Based on Normalized Vibration Spectra

An electronic engine-health-monitoring system is based on (1) computation of frequency-phase-normalized (FPN) spectra from the digitized outputs of vibration sensors and (2) the use of these spectra as feature vectors, which are presented to an artificial neural network for recognition of...

Briefs : Physical Sciences
Optical Remote Detection of Ice on Aircraft Surfaces

An imaging spectroscopic technique is undergoing development for use in remote detection of ice and mapping of the thickness of ice on aircraft surfaces. The technique is based on the variation of local spectral reflectance with the depth of ice and/or water on a surface of known aircraft...

Briefs : Information Technology
Algorithm for Initialization of a Convolutional Decoder

An algorithm effects rapid initialization of a convolutional decoder. This algorithm can be applied "on the fly"; that is while the decoder is receiving a stream of convolutionally encoded data. In comparison with other means of initialization, this algorithm is simpler, and it can be...

Briefs : Electronics & Computers
Embedded CMOS A/D Converters for High-Speed Operation

Sarnoff Corporation has announced the development of four new analog-to-digital (A/D) converter macro cells for embedding in CMOS designs in which high-precision, high-speed operation at low power is important. The 8-bit, 10-bit, 12-bit, and dual 6-bit designs are available for licensing by...

Briefs : Electronics & Computers
Parallel-Processing CDMA Detector With Neural Network

A proposed improved code-division multiple-access (CDMA) detector would achieve high resistance to jamming of weak ("far") received signals by strong ("near") ones. The problem of such jamming is called the "near/far problem," and resistance to such jamming is called "near/far resistance."...

Briefs : Physical Sciences
Transparent Furnaces for High-Temperature Research

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...

Briefs : Information Technology
Improved Parallel Computation of Electromagnetic Scattering

An improved method of parallel computation of the electromagnetic-scattering characteristics of complexly shaped objects has been devised. This method belongs to a class of methods that involve the finite-element solution of Maxwell's equations on unstructured grids. ("Unstructured...

Briefs : Electronics & Computers
Bound-to-Quasi-Bound Quantum-Well Infrared Photodetectors

Multiple-quantum-well AlxGa1 - xAs photodetectors that exploit transitions of electrons from quantum-well bound states to quasi-bound states are undergoing development for use at wavelengths from 6 to 25 µm. These photodetectors are intended to provide detectivities...

Briefs : Electronics & Computers
Sensor Combines Technologies to Achieve Application Versatility

By combining patented digital Silver-in-Glass® and analog conductive plastic technologies in a single environmentally sealed unibody package, Spectrol Electronics' DigiSense™ provides thousands of application-specific multifunction outputs (Figure 1). The conductive plastic...

Briefs : Physical Sciences
Measurements of Radiation in the Atmosphere

The recent summit meeting held in Kyoto, Japan, has brought world-wide attention to the issue of global climate change. For the past 5 years, the Department of Energy's Atmospheric Radiation Measurement - Unmanned Aerospace Vehicle (ARM-UAV) Program has been investigating the largest source of...

Briefs : Electronics & Computers
"Smart" Camera for Precise Mapping and Targeting

A "smart" video camera, called the "GI-Eye," generates digital image data that are automatically tagged with georegistration meta-data to indicate the precise position and attitude of the camera when the image was taken. This automatic georegistration streamlines the processing of the digital...

Briefs : Motion Control
Improved Roller and Gear Drives for Robots and Vehicles

Two types of gear drives have been devised to improve the performances of robotic mechanisms. One type features a dual-input/single-output differential-drive configuration intended to eliminate stick/slip motions; the other type features a single-input/dual-angular-momentum-balanced-output...

Briefs : Motion Control
Electrostatic Displacement Control Compensates for Spring

The figure schematically illustrates part of an accelerometer in which a feedback control subsystem applies voltages to generate electrostatic forces to minimize the displacement of a proof mass suspended on a spring. Older systems of this type provide active control of the displacements...

Briefs : Information Technology
Converting Particle-Fallout Data to Obscuration Levels

A worksheet has been constructed within the Microsoft Excel software system for converting raw particle-fallout data into percentages of obscuration; that is, percentages of areas obscured by particles on surfaces. These obscuration levels are needed for assessing contamination levels in...

Briefs : Electronics & Computers
Signal Preprocessor for Determining Time of Arrival

A proposed analog/digital circuit would improve the accuracy of determining the time of occurrence of a peak in an analog waveform. In the past, the time of occurrence of the peak was determined by comparing the magnitude of digital data samples. The time or clock pulse associated with the peak...

Briefs : Photonics/Optics
Photochromic Image-Plane Filter Extends Dynamic Range of CCD

A simple technique for extending the dynamic range of a charge-coupled-device (CCD) video camera involves the use of photochromic material — the same material used in self-adjusting sunglasses. The dynamic range of an image is the ratio between the maximum and minimum brightness...

Briefs : Mechanical & Fluid Systems
Updated Program for Computing Stresses in Spur Gears

DANST-PC is version 3.01 of a computer program for analysis of the statics and dynamics of spur-gear systems. ["DANST" signifies "Dynamic Analysis of Spur Gear Transmissions." A previous version was described in "Computing Stresses in Spur Gears," NASA Tech Briefs, Vol. 19, No. 12 (December...

Briefs : Physical Sciences
Microwave-Heating Technique for Batch Processing

A microwave-heating technique provides for batch processing of multiple, identically sized and shaped samples of the same material. The technique involves (1) excitation of a symmetrical electromagnetic mode or modes in a symmetrical microwave cavity and (2) positioning the samples symmetrically...

Briefs : Electronics & Computers
"Smart" Optoelectronic Sensor System for Recognizing Targets

The Viewing Imager/Gimballed Instrumentation Laboratory and Analog Neural Three-Dimensional Processing Experiment (VIGILANTE) is a "smart" optoelectronic sensor system that features ultrafast processing of image information for recognition and tracking of targets. VIGILANTE serves as...

Briefs : Robotics, Automation & Control
Doped ZnTe: a Developmental Photorefractive Material

Zinc telluride is a semiconductive material that has been found to become photorefractive when it is suitably doped with vanadium or with manganese and vanadium. The combination of photorefractivity and semiconductivity make this material attractive for use in a variety of applications,...

Briefs : Photonics/Optics
A Polymeric Optical Correlator for Security Verification

Rapid technological progress, especially in computers, CCD technology, color printers and scanners makes forgery and counterfeit of identification documents such as credit cards, or other important objects, increasingly simple. Current techniques such as the embossed hologram on credit...

Briefs : Robotics, Automation & Control
Snakelike Robots Would Maneuver in Tight Spaces

Robots with multiple-link arms that could reach through narrow openings into hidden cavities are undergoing development. Called "multifunction dexterous boro-robots" (MDBRs), these robots would resemble snakes (see Figure 1), in both general appearance and in the slithering motion with which they...

Question of the Week
Will Cooling Coatings Catch On?

Webcasts

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Using Simulation to Design Robust Adhesively Bonded Structures

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Electric-Vehicle Transmission Development and Simulation

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Thermal Management Crisis: Knowing Your Passive Solution Options

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IoT’s Role in Today’s Transportation Systems

On-Demand Webinars: Manufacturing & Prototyping

Testing and Inspecting 3D-Printed Parts

On-Demand Webinars: Manufacturing & Prototyping

3D Printed Metals Are Not All the Same