January 2000

Briefs : Information Technology
Developmental Software for Exploiting Hyperspectral Imagery

A unique state-of-the-art process for exploiting hyperspectral satellite imagery, based on evolutionary computing methods, has been developed and a proof-of-concept demonstration has been conducted. This development is projected to lead to several important commercial products,...

Briefs : Physical Sciences
Techniques for Controlling Buoyancy of Balloons on Titan

A report discusses alternative techniques for controlling the buoyancy, and thus the altitude and landings, of a balloon-borne instrumentation system that would be launched to explore the moon Titan of the planet Saturn. Some of the techniques are based on established concepts of heating...

Briefs : Information Technology
Algorithm for Rapid Acquisition of a PPM Optical Signal

An algorithm for rapid acquisition of a pulse-position-modulation (PPM) optical data signal implements a pattern-matching technique for synchronization of receiver timing with the temporal boundaries of data frames. Synchronization is necessary because in PPM, information is conveyed by the...

Briefs : Physical Sciences
Lightweight, Low-Power, Inexpensive Ozone Dosimeters

Lightweight, low-power-consumption, inexpensive ozone sensors based on colorimetric chemical sensing would be developed, according to a proposal. Colorimetric chemical sensing is an established technique, but it has not been applied previously to sensing of ozone. The proposed ozone sensors...

Briefs : Materials
Update on Electrolytes for Low-Temperature Lithium Cells

A report presents results of research on carbonate-based electrolytes to improve the low-temperature-performances of lithium-ion rechargeable electrochemical cells. The loss of performance with decreasing temperature is attributable largely to a decrease of ionic conductivity and the...

Briefs : Medical
Noninvasive Test Detects Cardiovascular Disease

A technique for noninvasive determination of the pressure in the cerebrospinal fluid (CSF) has been proposed. This technique would involve two main steps: First, an optical coherence tomographic scanner would be aimed into an eye and used to image the optical disk (see figure). Next, the resulting...

Briefs : Mechanical & Fluid Systems
Bushing-Mounted Drag Chain

The figure illustrates a chair-base mechanism with a bushing-mounted drag chain. The bushing-mount design provides for one end of the drag chain to be free to pivot; this provision makes it possible to wrap the drag chain to a radius smaller than that achievable in mechanisms previously designed for the same purpose....

Briefs : Medical
Improved Urine Preservative

An improved solution for preserving samples of urine has been formulated. This solution preserves a much broader spectrum of analytes in urine than do other urine-preservative solutions here-tofore in use by NASA, and is safe for use by humans. When this solution is used, (1) refrigeration of urine samples is not...

Briefs : Medical
Primers for Amplifying CMV DNA in Body Fluids and Tissue

A novel set of primers has been developed for use in a polymerase chain reaction (PCR) to amplify the deoxyribonucleic acid (DNA) of cytomegalovirus (CMV). The purpose of this development is to enable faster, more sensitive detection of CMV virus infecting body fluids and tissues.

Briefs : Software
The Automated Fatigue Calculation Program (FATPLUS)

Since it was developed in the late 1980s, the Automated Fatigue Calculation Program (FATPLUS) has consistently demonstrated its ability to predict fatigue life, independently validate proprietary fatigue methodologies, identify fatigue-sensitive parts, and train engineers in predicting...

Briefs : Physical Sciences
Temperature Correction for Pressure-Sensitive Paint

A temperature correction has been developed to enable the extraction of pressure images and corresponding pressure data from images of photoluminescence of pressure-sensitive paints (PSPs). These paints are used on wind-tunnel models for mapping surface pressures associated with supersonic flow...

Briefs : Electronics & Computers
Studies of Interaction Impedance in a TWT Helix

Two reports present further developments in the subject of "Computation of Characteristics of a Helical TWT Slow-Wave Circuit" (LEW-16571), NASA Tech Briefs, Vol. 22, No. 4 (April 1998), page 54. The subject is computation, by use of the MAFIA (Solution of MAxwell's Equations by the...

Briefs : Physical Sciences
High-Temperature Pressure Sensors Made From Silicon Carbide

Pressure sensors that contain thin diaphragms made from the 6H polytype of silicon carbide (6H-SiC) have been developed. These are prototypes of pressure sensors for use at high temperatures in engines, power plants, material-processing systems, and numerous other applications.

Briefs : Electronics & Computers
Piezoelectric Igniter/Pressure-Sensor Devices

Piezoelectric devices that would serve as spark plugs, power generators for spark plugs, and/or pressure sensors have been proposed for use in internal-combustion engines. Unlike conventional spark plugs, these devices would function without need for wire connections to external high-voltage sources....

Briefs : Electronics & Computers
Tunable HTS/Ferroelectric Microstrip Band-Pass Filters

Electrically tunable microstrip two-pole band-bass filters for a center frequency near 19 GHz and a 4-percent bandwidth have been designed, fabricated, and demonstrated to be functional. These filters are suitable for use in the front ends of K-band communication receivers that operate at...

Briefs : Materials
Reducing Methanol Crossover in CH3OH-Fuel-Cell Membranes

Improved polymer electrolyte membranes for direct methanol fuel cells can be made by impregnating the baseline membrane material with cross-linked polystyrene (a copolymer of styrene and divinylbenzene). The baseline membrane material is a perfluorosulfonic acid-based hydrophilic,...

Briefs : Mechanical & Fluid Systems
Inflatable Wing Leading Edges for High Lift and Deicing

Computational simulations and wind-tunnel tests have demonstrated the feasibility of using inflatable boots on the leading edges of airplane wings, both as devices to increase lift and as pneumatic deicing actuators. Assuming success in further research and development, the first...

Briefs : Information Technology
Expert System To Develop Job Standards

The Job Standards Development System is a user-friendly expert system that (1) helps users select an appropriate work measurement methodology to develop job standards (or the less formal job time estimates) and (2) leads the users through the steps necessary to use a work time estimating technique to...

Briefs : Information Technology
Further Developments in Web Interactive Training

Three innovative computer programs for training and testing personnel at Kennedy Space Center have been developed under the aegis of the Web Interactive Training (WIT) project. The WIT project exploits the capabilities afforded by the Internet and by state-of-the-art multimedia data-presentation...

Briefs : Electronics & Computers
Using Narrow-Band Data Links in Locating Lightning Strikes

A method of preprocessing lightning-measurement waveforms has been devised to reduce the bandwidth needed to transmit data for computing the locations of lightning strikes. The method is used in a system in which electric fields and electric-field derivatives induced by lightning are...

Briefs : Electronics & Computers
Centralized Electronic Reporting of Material-Science Tasks

The Materials Science Division (MSD) at Kennedy Space Center is developing a computer system to maintain a material-science data base coupled with a user-friendly interface on the World Wide Web. The system is designed to eliminate the need for time-consuming and expensive distribution...

Briefs : Mechanical & Fluid Systems
Nonintrusive Flow-Measurement System

A nonintrusive flow-measurement system based on ultrasonics has been developed to replace a system based on turbine flowmeters. A turbine flowmeter must be mounted in line with a pipe; this raises the possibility of leakage at the flowmeter/pipe joints, and the flowmeter unavoidably perturbs the flow....

Briefs : Materials
Composite-Material Heat Sink for Printed-Circuit Boards

A laminated composite-material plate has been developed for use as a lightweight heat sink and mechanical support for rigid printed-circuit boards (PCBs) that hold surface-mounted electronic components. This composite-material plate is intended to replace a conventional aluminum heat-sink...

Briefs : Information Technology
Post-Processing Satellite Image Data in Secondary Schools

Never before have secondary schools been able to post-process raw satellite data, and now they can do it in real time. This is credited to advances in technology that have recently made the necessary equipment simple, inexpensive, powerful, and available enough for any school to fit into...

Briefs : Electronics & Computers
Return-Link Processor PCI Card

The return-link processor card (RLP) performs all of the fundamental data-processing functions involved in the return of satellite telemetry, in real time at rates up to 400 Mb/s, using industry-standard interface circuitry and connectors with standard sizes and shapes. Previously, four cards, each containing a...

Briefs : Physical Sciences
GFSSP — Program for Analyzing Flows in a Complex Network

The Generalized Fluid System Simulation Program (GFSSP) version 2.01 is a general-purpose computer program for analyzing steady-state and time-dependent flowrates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling phase changes,...

Briefs : Photonics/Optics
Software for Processing Data in Particle-Image Velocimetry

PIVPROC is a computer program for processing data in particle-image velocimetry (PIV), which is a method of determining a flow velocity field from images of small seed particles that are entrained in the flow and that are illuminated by laser pulses at known intervals of time. PIVPROC...

Briefs : Photonics/Optics
Current-Mode Dark-Level Subtraction in LWIR Imaging

A complementary metal oxide/semiconductor (CMOS) focal-plane readout circuit for an imaging array of long-wavelength infrared (LWIR) photodetectors effects in-pixel current-mode subtraction of the dark-level component of each photodetector output. The dark-level signal is subtracted before the...

Briefs : Photonics/Optics
High-Power, Wideband Laser-Diode Transmitter Module

A prototype compact, rugged optomechanical module contains a high-power, wideband laser-diode transmitter. The laser diode is of a commercial single-quantum-well AlGaAs type. Each laser diode of this type is manufactured for a specific nominal wavelength in the range from 810 to 860 nm; the...

Briefs : Photonics/Optics
Segmented-Cold-Cathode Display Panels

Display panels based largely on the principles of proximity-focused image-intensifier tubes have been proposed as alternatives to cathode-ray tubes (CRTs) and other conventional devices for wide displays. A panel of the proposed type would afford the high brightness and wide viewing angle (almost 180°) of...

Briefs : Photonics/Optics
Method of Measuring Encircled Energy for Imaging Optics

The radial distribution of energy within an image, called encircled energy, is a classical measure of the quality of the optical system producing that image. An improved method for measuring encircled or enclosed energy for imaging optical systems makes use of precisely micromachined...

Briefs : Photonics/Optics
Telescope for Imaging and Laser Communication

Miniature, single-aperture optoelectronic instruments called "multi-function telescopes" are being developed for use in both scientific observations and laser communications aboard microspacecraft that are expected to be launched in the next few years. These instruments could also be adapted to...