0
21300
30
Briefs: Physical Sciences
Improved Compression of Wavelet-Transformed Images

A recently developed data-compression method is an adaptive technique for coding quantized wavelet-transformed data, nominally as part of a complete image-data compressor. Unlike some other approaches, this method admits a simple implementation and does not rely on the use of large code...

Briefs: Physical Sciences
Stroboscopic Interferometer for Measuring Mirror Vibrations

Stroboscopic interferometry is a technique for measuring the modes of vibration of mirrors that are lightweight and, therefore, unavoidably flexible. The technique was conceived especially for modal characterization of lightweight focusing mirror segments to be deployed in outer space;...

Briefs: Physical Sciences

A dilatometer based on a laser interferometer is being developed to measure mechanical creep and coefficients of thermal expansion (CTEs) of materials at temperatures ranging from ambient down to 15 K. This...

Feature Image
Briefs: Test & Measurement

Lightweight, flexible probes have been developed for measuring temperatures at multiple locations in tanks that contain possibly pressurized cryogenic fluids. If the fluid in a given...

Feature Image
Briefs: Materials
Improved Charge-Transfer Fluorescent Dyes

Improved charge- transfer fluorescent dyes have been developed for use as molecular probes. These dyes are based on benzofuran nuclei with attached phenyl groups substituted with, variously, electron donors, electron acceptors, or combi- nations of donors and acceptors. Optionally, these dyes could be...

Briefs: Electronics & Computers
Portable Airborne Laser System Measures Forest-Canopy Height

The Portable Airborne Laser System (PALS) is a combination of laser ranging, video imaging, positioning, and data-processing subsystems designed for measuring the heights of forest canopies along linear transects from tens to thousands of kilometers long. Unlike prior laser ranging...

Briefs: Electronics & Computers

Inexpensive, lightweight array antennas on flexible substrates are under development to satisfy a need for large-aperture antennas that can be stored compactly during transport and deployed to full...

Feature Image
Briefs: Electronics & Computers

A prototype optoelectronic system measures the three dimensional relative coordinates of objects of interest or of targets affixed to objects of interest in a workspace. The system includes a...

Feature Image
Briefs: Photonics/Optics

Integrated circuits that exploit optical flow to sense motions of computer mice on or near surfaces (“optical mouse chips”) are used as navigation sensors in a class of small flying robots...

Feature Image
Briefs: Mechanical & Fluid Systems
Lifting Mechanism for the Mars Explorer Rover

A report discusses the design of a rover lift mechanism (RLM) — a major subsystem of each of the Mars Exploration Rover vehicles, which were landed on Mars in January 2004. The RLM had to satisfy requirements to (1) be foldable as part of an extremely dense packing arrangement and (2) be...

Briefs: Semiconductors & ICs

A modification in a method of automated evolutionary synthesis of voltage controlled multifunctional logic circuits makes it possible to synthesize more circuits in less time. Prior to...

Feature Image
Briefs: Semiconductors & ICs
N-Type d Doping of High-Purity Silicon Imaging Arrays

A process for n-type (electron-donor) delta (d) doping has shown promise as a means of modifying back-illuminated image detectors made from n-doped high-purity silicon to enable them to detect high-energy photons (ultraviolet and x-rays) and low-energy charged particles (electrons and ions)....

Briefs: Materials
Making Activated Carbon for Storing Gas

Solid disks of microporous activated carbon, produced by a method that enables optimization of pore structure, have been investigated as means of storing gas (especially hydrogen for use as a fuel) at relatively low pressure through adsorption on pore surfaces. For hydrogen and other gases of practical...

Briefs: Materials

Comparative tests have been performed to evaluate the corrosion-prevention capabilities of an experimental paint of the type described in "Water-Borne,...

Feature Image
Briefs: Medical
Chamber for Growing and Observing Fungi

Unlike prior fungus growing apparatuses, this chamber makes it possible to examine a fungus culture without disrupting it. Partly resembling a small picture frame, the chamber includes a metal plate having a rectangular through the thickness opening with recesses for a top and a bottom cover glass, an...

Briefs: Materials

A sol-gel process has been developed as a superior alternative to a prior process for making platinum-ruthenium alloy catalysts for electro-oxidation of methanol in fuel cells. The...

Feature Image
Briefs: Medical

A prototype of an electroporation system for sterilizing wastewater or drinking water has been developed. In electroporation, applied electric fields cause transient and/or permanent changes in...

Feature Image
Briefs: Software
Data-Acquisition Software for PSP/TSP Wind-Tunnel Cameras

Wing-Viewer is a computer program for acquisition and reduction of image data acquired by any of five different scientific grade commercial electronic cameras used at Langley Research center to observe wind-tunnel models coated with pressure or temperature-sensitive paints (PSP/TSP).

Briefs: Software
Grid Visualization Tool

The Grid Visualization Tool (GVT) is a computer program for displaying the path of a mobile robotic explorer (rover) on a terrain map. The GVT reads a map-data file in either portable graymap (PGM) or portable pixmap (PPM) format, representing a gray-scale or color map image, respectively.

Briefs: Software
Updated Chemical Kinetics and Sensitivity Analysis Code

An updated version of the General Chemical Kinetics and Sensitivity Analysis (LSENS) computer code has become available. A prior version of LSENS was described in “Program Helps to Determine Chemical-Reaction Mechanisms” (LEW-15758), NASA Tech Briefs, Vol. 19, No. 5 (May 1995), page 66....

Briefs: Software
Avionics System Architecture Tool

Avionics System Architecture Tool (ASAT) is a computer program intended for use during the avionics-system-architecture- design phase of the process of designing a spacecraft for a specific mission.

Briefs: Software
Predicting Flutter and Forced Response in Turbomachinery

TURBO-AE is a computer code that enables detailed, highfidelity modeling of aeroelastic and unsteady aerodynamic characteristics for prediction of flutter, forced response, and bladerow interaction effects in turbomachinery.

Briefs: Mechanical & Fluid Systems
System Regulates the Water Contents of Fuel-Cell Streams

An assembly of devices provides for both humidification of the reactant gas streams of a fuel cell and removal of the product water (the water generated by operation of the fuel cell). The assembly includes externally-sensing forward-pressure regulators that supply reactant gases (fuel and...

Briefs: Manufacturing & Prototyping

A micromachining process for the fabrication of vibratory microgyroscopes from silicon wafers, and aspects of the microgyroscope design that are inextricably linked with the...

Feature Image
Briefs: Manufacturing & Prototyping
Two Heat-Transfer Improvements for Gas Liquefiers

Two improvements in heat-transfer design have been investigated with a view toward increasing the efficiency of refrigerators used to liquefy gases. The improvements could contribute to the development of relatively inexpensive, portable oxygen liquefiers for medical use.

Briefs: Mechanical & Fluid Systems

The Five-Axis, Three-Magnetic-Bearing Dynamic Spin Rig is an apparatus for vibration testing of turbomachine blades in a vacuum at rotational speeds from 0 to 40,000 rpm. This rig (see...

Feature Image
Briefs: Aerospace
Stellar Gyroscope for Determining Attitude of a Spacecraft

A paper introduces the concept of a stellar gyroscope, currently at an early stage of development, for determining the attitude or spin axis, and spin rate of a spacecraft. Like star trackers, which are commercially available, a stellar gyroscope would capture and process images of stars...

Briefs: Physical Sciences

An optical communications terminal (OCT) is being developed to enable transmission of data at a rate as high as 2.5 Gb/s, from an aircraft or spacecraft to a ground station. In addition to...

Feature Image
Briefs: Physical Sciences

The figure depicts the planned Actuated Hybrid Mirror Telescope (AHMT), which is intended to demonstrate a new approach to the design and construction of wide-aperture spaceborne telescopes for astronomy and...

Feature Image

Webcasts

Feature Image
On-Demand Webinars: Defense

From Data to Decision: How AI Enhances Warfighter Readiness

Feature Image
Upcoming Webinars: Aerospace

April Battery & Electrification Summit

Feature Image
Upcoming Webinars: Manufacturing & Prototyping

Tech Update: 3D Printing for Transportation in 2024

Feature Image
Upcoming Webinars: Materials

Unleashing Epoxy's Potential: Ensuring Hermetic Sealing in Modern...

Feature Image
Upcoming Webinars: Test & Measurement

Building an Automotive EMC Test Plan

Feature Image
Upcoming Webinars: Aerospace

The Moon and Beyond from a Thermal Perspective

Videos