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 : Physical Sciences
Combination of Cryotrapping and SPME for GC/MS Analysis

An improved process has been devised for acquiring and preparing trace amounts of airborne organic compounds for analysis by a gas chromatograph and mass spectrometer (GC/MS). A sample of air is passed through a cryotrap, where organic compounds and water vapor condense on the wall of a...

Briefs : Mechanical & Fluid Systems
Multichannel Ultrasonic-Bolt-Tension-Gauge System

An improved system for measuring tensions in multiple bolts is based on the usual measurement of the times of propagation of ultrasonic waves along the bolts, but the quantities measured and the method of processing the measurement data differ from those of conventional ultrasonic bolt-tension...

Briefs : Photonics/Optics
Autostereoscopic Displays for Scientific Visualization

Many types of scientific images and data are complex and are easier to interpret when observed in three dimensions. This is especially true for information presented visually in the form of multiparameter graphs and tables, as well as for images of physical events, such as turbulent flows....

Briefs : Physical Sciences
Measuring Velocity of Ice by SRI Using Ascending and Descending Passes

A method of satellite radar interferometry (SRI) enables the remote measurement of three-dimensional velocities of ice flow over large areas of glaciers. At present, ice-flow velocities are measured primarily in situ by use of the Global Positioning System (GPS) in a...

Briefs : Physical Sciences
Determining Characteristics of Wind-Borne Particles

A small, robust, lightweight, low-power-consumption instrumentation system has been proposed for determining the kinetic energies, masses, and other parameters of wind-borne particles. Originally intended for use in future exploration of Mars, the system might also prove useful on Earth for...

Briefs : Electronics & Computers
Computation of Characteristics of a Helical TWT Slow-Wave Circuit

A computational study has been performed to show that one can accurately compute the cold-test electromagnetic characteristics of the helical slow-wave circuit of a traveling-wave tube (TWT).

Briefs : Physical Sciences
Electrochemical Monitoring of Hydrazine in Air

An instrumentation system monitors ambient air to determine whether hydrazine vapor is present in sufficient concentration to be harmful to humans or equipment. The system can measure hydrazine concentrations as low as 10 parts per billion (ppb); this level of concentration is denoted the threshold...

Briefs : Physical Sciences
Electrostatic Dispersion of Fuel Drops To Reduce Soot

Electrostatic dispersion of drops of sprayed liquid fuel has been proposed as a technique for reducing the amount of soot formed during burning of the fuel. It is necessary to disperse fuel drops in order to reduce local concentrations of fuel-rich vapors, because such concentrations favor...

Briefs : Information Technology
System for Locating Objects of Interest in Image Data Bases

A trainable software system known as JARtool 2.0 has been developed to help scientists find localized objects of interest ("target objects") in image data bases. A human expert implicitly trains the system by using a graphical user interface (see figure) to circle all examples of the...

Briefs : Electronics & Computers
Glove Senses Angles of Finger Joints

A glove has been instrumented to sense the angles of finger joints via the electrical resistances of strips of an electrically conductive elastomer on the backs of the fingers, including the thumb (see figure). The conductive elastomer is a urethane-based synthetic rubber filled with conductive carbon...

Briefs : Photonics/Optics
Line-Focus Photovoltaic Module With Solid Secondary Optics

The figure illustrates aspects of a lightweight, relatively inexpensive solar photovoltaic module suitable for use on Earth or in outer space in conjunction with at least a single-axis Sun-tracking apparatus. The module contains line-focus primary Fresnel lenses that act in conjunction...

Briefs : Photonics/Optics
Endoscopic Shearography Inspection

An imaging method to detect flaws in composite pressure vessels used in the aerospace industry has been developed. Solid-rocket-motor casings and fuel or oxidizer tanks for liquid rocket motors can now be evaluated with the endoscopic shearography inspection device.

Briefs : Physical Sciences
Stereoscopic, Three-Dimensional PIV With Fuzzy Inference

An all-electronic digital particle-image velocimetry (PIV) system has been developed for use in measuring three-dimensional velocities at numerous points throughout a plane of interest in a supersonic flow. This system includes two high-resolution charge-coupled-device (CCD) video cameras...

Briefs : Electronics & Computers
Discriminator-Stabilized Superconductive/Ferroelectric Oscillator

An oscillator circuit that contains superconductive and ferroelectric resonator elements is undergoing development. This circuit is designed to serve as a frequency-locked local oscillator in a communication system in which digital data are conveyed via phase modulation on a...

Briefs : Physical Sciences
Scanning-Mode Shadowgraphy for Examining Shock Waves

Scanning-mode shadowgraphy has been proposed as an alternative optical technique for diagnosis of shock waves. Under suitable conditions, scanning-mode shadowgraphy could overcome the limitations of classical shadowgraphy in such a way as to make shock waves more visible and measurable.

Briefs : Software
Quick and Unusually Easy Repository Search Software

The Quick and Unusually Easy Repository Search computer program simplifies the search for information contained in a repository of documents at Marshall Space Flight Center. Searching for information on the basis of general subjects can be very time-consuming and frustrating: The repository at...

Briefs : Physical Sciences
Sonochemical Treatment To Remove Hydrazines From Water

A sonochemical treatment has been proposed for removing hydrazine contaminants from water. The basis of the proposal is a conjecture that the sonochemical effect in water containing hydrazines would cause the hydrazines and some of the water to decompose, forming relatively innocuous...

Briefs : Information Technology
Image Compression for High-Performance Computing

A program of research on the use of wavelets for compression of data in a parallel-computing environment has led to development of a scheme for compressing image data. The purpose of the research was to determine whether one could achieve an acceptably high compression ratio with acceptably small...

Briefs : Photonics/Optics
Thermal-Desorption X-Ray Photoelectron Spectroscopy

Thermal-desorption x-ray photoelectron spectroscopy (TDXPS) is a technique in which the thermal aspect of thermogravimetric analysis (TGA) is combined with non-angle-resolved x-ray photoelectron spectroscopy (XPS). TDXPS was developed to enhance the physical and chemical characterization of...

Briefs : Mechanical & Fluid Systems
Automated Calibration of Torque Analyzers Without Weights

An automated apparatus calibrates digital torque analyzers that, in turn, are used to verify the accuracies of torque wrenches. The apparatus is located in a central laboratory, and the digital torque analyzers are brought to the laboratory for calibration. Previously, the torque...

Briefs : Photonics/Optics
Ultraviolet Hygrometer

An ultraviolet hygrometer has been developed that uses an optical technique to provide fast response, stable calibration, and immunity to airborne contaminants. It is a two-wavelength two-path instrument that relies on the differential absorption by water vapor of two wavelengths in the vacuum ultraviolet. The differential...

Briefs : Photonics/Optics
Optical Processing Furnace

NREL scientists have developed an optical processing furnace that combines photonic effects of light with heat to selectively induce reactions at far lower temperatures than they would be if caused by heat alone. In addition to saving energy for standard processing steps and producing devices with higher ohmic quality,...

Briefs : Materials
Two Methods for Purifying Carbon Tetrachloride

Two methods have been developed to purify large batches of technical-grade carbon tetrachloride. The relatively impure carbon tetrachloride that had been purchased for use in infrared analysis of dissolved hydrocarbons proved that it could be purified. One method is spinning-band distillation, which...

Briefs : Manufacturing & Prototyping
Controlled-Orientation Short-Fiber Composite Bodies

A technique for depositing materials into position using a positive-displacement extruder to build up a body has been developed. This technique also includes a process to prepare composite materials through a solid free-body forming process containing directionally aligned short-fiber...

Briefs : Physical Sciences
Genetic Algorithms Help Design Dielectric Grating Filters

A computational method for designing all-dielectric grating electromagnetic filters involves a combination of (1) numerical simulation of filter performance via integral-equation solution of Maxwell's equations and (2) genetic algorithms to find acceptable combinations of filter-design...

Briefs : Materials
Nitrogen-Beam Source for Deposition of III/V Nitrides

A nitrogen-beam source has been developed to significantly improve the synthesis of wide-band-gap nitrides.

Briefs : Physical Sciences
Automated Dew-Point/Frost-Point Humidity Generator

The figure schematically illustrates an improved apparatus for generating a flow of gas with precise, stable humidity. Such flows are needed for calibration of dew-point, frost-point, and other humidity sensors.

Briefs : Electronics & Computers
Induced-Eddy-Current-Sensor Measurement of Semiconductor Performance

Recombination lifetime and minority-carrier lifetime are key performance parameters of semiconductor wafers used for microelectronics and solar cells. They are also particularly valuable for identifying low levels of impurities in wafers used for high-density integrated...

Briefs : Electronics & Computers
Radiative Measurement of Temperature in a MESFET Channel

A technique based on infrared-emission spectroscopy has been found to be useful for noncontact measurement of the temperature of a hot spot in the gate channel of a GaAs metal/semiconductor field-effect transistor (MESFET). Temperature measurements are important for the development of...

Briefs : Electronics & Computers
Rechargeable Microbatteries With Li Anodes Formed In Situ

Rechargeable, thin-film, lithium-based microbatteries of the proposed type would be manufactured in the discharged condition, and lithium anodes would be formed in situ during subsequent charging. In contrast, state-of-the-art rechargeable, thin-film, lithium-based microbatteries are...

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