September 2002

Briefs : Materials
Fabricating Better PSSA-PVDF-Based MEAs for Fuel Cells

Some changes have been made in the fabrication of PSSA/ PVDF-based membrane/electrode assemblies for direct methanol fuel cells. The effect of the changes is to improve the electrochemical performances of the cells.

Briefs : Software
Software for Capturing Software-Design Rationale

Better Elicitation and Communication of Arguments Underlying Software Engineering (BECAUSE) is a computer program that records and codifies the rationale that underlies decisions made in the course of developing software. To minimize the additional sensory, cognitive, and motor demands upon the...

Briefs : Software
Software for Scientific Exploration by Multiple Rovers

Multi-Rover Integrated Science Understanding System (MISUS) is a computer program designed to coordinate the activities of multiple small, instrumented robotic vehicles (rovers) engaged in autonomous scientific exploration of the surface of Mars. MISUS includes a component that utilizes...

Briefs : Software
Software Accelerates and Standardizes Procurement by NASA

Virtual Procurement Office (VPO) is a Web-based application program designed for use by procurement professionals throughout NASA. Prior to the development of VPO, each of the 700+ NASA procurement pro- fessionals had to spend much time searching numerous locations on-line and off-line...

Briefs : Software
Software for Managing a Health and Environmental Database

Health and Environ- mental Resource System (HERS) is a relational-database computer program with a graphical user interface that assists members of an envi- ronmental health organization in the collection, analysis,

and reporting of data pertaining to industrial hygiene, radiation...

Briefs : Software
GUI Software for Managing Router Configuration Files

Cisco IOS Manager (CIOSMAN) is a computer program that generates a graphical user interface for managing configuration files for an Internet-Protocol router. [In this context, “IOS” signifies the Cisco Internet- working Operating System and “router” signifies a system of...

Briefs : Electronics & Computers
Making Audible Alarms More Noticeable in Noisy Environments

An improved method of generating audible alarms has been invented for stressful environments in which there may be consid- erable background noise and where the intended recipients of the alarms also need to pay att- ention to sounds other than the alarms. An aircraft cockpit is a...

Briefs : Electronics & Computers
Clamps for Testing Cable Shields and Connector Shells

Connector test clamps (CTCs) are clamping electrical connectors designed for use in testing electrical continuity from the backshell of a connector at one end of a shielded electrical cable, through the cable shield, to the backshell at the other end of the cable. CTCs increase the...

Briefs : Electronics & Computers
Remote Sense Helps Power Sources Accurately Simulate Batteries and Charger Operation

During development and production, cell phones and other portable devices must be tested and calibrated with a power source that accurately simulates battery operation. To avoid erroneous calibration and false failure indications in devices under test (DUTs),...

Briefs : Information Technology
Methods and Software for Mining Data in Context

The Perilog methods and software provide a suite of data-mining tools. Perilog retrieves and organizes data from any sequence of terms that are contextually associated (e.g., text, music, genetic sequences). Perilog data mining includes: (1) keyterm-in-context search; (2) flexible, model-based...

Briefs : Information Technology
Beacon-Based Exception Analysis for Multimissions

BEAM is a method of real-time, automated analysis and diagnosis applicable to a broad class of complex electromechanical systems, including spacecraft, aircraft, and process-control systems. Some aspects of its operation were described in “Reusable Software for Autonomous Diagnosis of Complex...

Briefs : Information Technology
Generalized Pre-Processor for Block and Convolutional Codes

A generalized data processor, proposed for use in the reception of binaryphase-shift-keyed (BPSK) radio signals, provides preliminary estimates of the block and convolutionally encoded symbols that are meant to be con- veyed by the BPSK modulation. In a process denoted...

Briefs : Information Technology
Improved Transponder for Earth/Spacecraft Communication

A prototype of a relatively inexpensive S-band transponder has been developed for use aboard a spacecraft as part of a NASA space- craft tracking and data network (STDN). The transponder design incorporates recent advances in digital processing of received radio signals. Notable features of...

Briefs : Information Technology
Analyzing Multispectral Signatures and Images of Biomaterials Through Neural Computing

A method of semi- automated ident- ification of biomaterials, now under development, is based on the use of a combination of neural-network and of self- organizing, molecular, and supervised-learning algorithms to analyze multispectral images. The method is...

Briefs : Electronics & Computers
Extending the Life of a Linear Tape-Open (LTO) Backup Tape

Data is any company’s most valuable asset. Archiving systems are essential to ensuring that valuable data is preserved. A wide variety of technologies exists, but tape medium remains a popular choice for data backup due to its comparatively low cost and large capacity for data storage....

Briefs : Materials
Making Hydrophobic Cathodes for MEAs in Fuel Cells

The fabrication of membrane/electrode assemblies (MEAs) for direct methanol fuel cells can be modified to make the cathodes hydro- phobic. These modifications improve the performances of the fuel cells, as explained below.

Briefs : Materials
Improved Polymer/Solid-Electrolyte Membranes for Fuel Cells

A class of developmental membrane electrolyte materials for methanol/air and hydrogen/air fuel cells is exemplified by a composite of (1) a melt-processable polymer [in particular, poly(vinylidene fluoride) (PVDF)] and (2) a solid proton conductor (in particular, cesium hydrogen...

Briefs : Materials
Nontoxic X-Ray-Absorbing Windows

Windows that absorb x rays and are transparent to visible light can be made by compression molding of tantalum oxide/polymer composite materials. The main x-ray-absorbing medium in these windows is tantalum instead of lead, which is the traditional main x-ray-absorbing medium. These composite windows have been...

Briefs : Mechanical & Fluid Systems
Computational Test Cases for Oscillating Clipped Delta Wing

Computational test cases have been selected from archived sets of data acquired some years ago in wind-tunnel experiments on a clipped delta wing equipped with a hydraulically actuated trailing-edge control surface. In some of the experiments, the wing was subjected to pitching...

Briefs : Mechanical & Fluid Systems
Control Derivatives of the F-18 Airplane

Flight data gathered by use of the F-18 System Research Aircraft (SRA) based at Dryden Flight Research Center have been used to estimate stability and control derivatives for a baseline F-18 airplane. The data were obtained in the high-dynamic-pressure range of the F-18 flight envelope in an experiment...

Briefs : Mechanical & Fluid Systems
Ultrasonically Induced Fountains and Fogs

Experiments have demonstrated the feasibility of generating fountains and fogs over a body of water (see Figure 1) by utilizing high-intensity ultrasound to induce acoustic streaming, cavitation, and atomization. The transducer used in the experiments had a 10-cm diameter and a 10-cm focal length, was...

Briefs : Mechanical & Fluid Systems
Fail-Safe, Continue-to-Operate Concept for Jackscrews

A fail-safe, continue-to-operate design concept for machine jackscrews calls for the incorporation of a redundant follower nut that would assume the axial jack load upon failure of the...

Briefs : Mechanical & Fluid Systems
Pulse-Tube Refrigerator for Liquid Hydrogen

An improved closed-loop, two-stage pulse-tube refrigerator provides 4 W of cooling power at a temperature of 15 K. The original intended application of this refrigerator is in preventing boiloff of liquid hydrogen from a propellant tank aboard a spacecraft. The basic refrigerator design can also be...

Briefs : Mechanical & Fluid Systems
Ultrasonic/Sonic Vibrating/Rotating Tool Bits

An easy-to-implement design concept shows promise for improving the performances of impact tool bits used in abrading surfaces, drilling, and coring of rock and rocklike materials. The concept is especially applicable to tools actuated with a combination of ultrasonic and sonic vibrations, as in the...

Briefs : Medical
Noninvasive Assessment of Human Fine Motor Control

A report presents additional information about the Impairscope — an instrument for noninvasive meas- urement of fine neuromuscular control and, more particularly, for quantifying the degradation of neuromuscular performance under psychological stress. The instrument, previously called the...

Briefs : Medical
Enhanced Bioproduction and Extraction of Taxanes

Several groups of methods of enhanced bioproduction and extraction of taxanes have been invented. Taxanes (see figure) have exhibited potential as drugs for treatment of cancer and congenital polycystic kidney disease. One taxane — paclitaxel (more widely known under the trade name Taxol™) —...

Briefs : Medical
Steam Sterilization of a Packed Column Without Admitting Air

A procedure has been devised for the use of steam to sterilize a water-purification cartridge, chrom- atographic column, or other closed packed column that is required to be kept filled with water and from which it is required to exclude air bubbles, which could impede flow. For the...

Briefs : Medical
Water-Microbiology Kit

Materials and equipment for determining whether samples of potable water contain harmful microbes have been packaged in a kit. Designed for use aboard spacecraft, the kit is also suitable for terrestrial use in a laboratory or in the field. The kit holds the sample, nutrient, and waste liquids in a closed system.

Briefs : Physical Sciences
Optical Fourier-Plane Analysis of Suspended Particles

Optical Fourier-plane analysis may prove useful for obtaining statistical data on the densities, sizes, shapes, indices of refraction, and perhaps other properties of particles (particularly, biological cells) suspended in liquids. This concept could potentially be the basis of a new class of...

Briefs : Physical Sciences
Preparing High-Quality Micrographic Samples of Oil Paintings

A technique similar to that of metallography has been devised for preparing cross-sectional micrographic specimens from small samples cut from oil paintings. Art experts at the Cleveland Museum of Art use the technique in their efforts to determine painters’ methods and to verify the...

Briefs : Physical Sciences
Pyrolytic-Graphite Gauges for Measuring Large Heat Fluxes

Gauges made of slugs of pyrolytic graphite with thermocouples em- bedded in them have been invented for use in measuring large, short-duration heat fluxes in hot, highly corrosive environments. These gauges were originally intended for use in combustion chambers of rocket engines; they...

Briefs : Physical Sciences
Wind and Mountain Wave Observations From a Flight Test of a Solar-Powered Airplane

In support of NASA’s Environmental Research Aircraft and Sensor Technology (ERAST) program, flight tests of the Pathfinder solar-electric-powered, remotely piloted aircraft (RPA) were conducted at the Navy’s Pacific Missile Range Facility (PMRF), Barking...

Briefs : Physical Sciences
Electrostatic Systems Keep Dust Off Surfaces

Electrostatic dust- collection systems that comprise wire grids connected to lightweight, low-power high-voltage sources have been invented for preventing the accumulation of dust on surfaces. Intended originally for use in keeping spacecraft solar panels free of dust, these systems could also be used...

Briefs : Materials
Research on Life-Prediction Methods for MMCs— Phase I

A report describes the completed first phase of a NASA/industry cooperative program of research on metal-matrix composites (MMCs) as lightweight, strong, high- temperature-resistant materials for use in future aircraft engines. The first phase of the research included assessment of life-...

Briefs : Information Technology
Wavelet-Based Time-Varying Models of Pilots in Control Loops

A report presents a study of the use of wavelet-based mathematical models to quantify the responses of humans in control loops. The report begins with a review of the traditional representation of manual control responses by use of transfer functions derived from Fourier transforms,...

Briefs : Photonics/Optics
Spectral Region for Laser Isotope Measurements of Gases

A mid-infrared wave-number range has been identified as being useful for laser measurements of CO and CO2 gases that contain various combinations of isotopes of C and O. The isotopic species are 12C16O (common CO), 13C16O,...

Briefs : Photonics/Optics
Reflective Variants of Miniature Microscope Without Lenses

The figure schematically depicts two proposed alternative versions of an instrument that amounts, in effect, to a compact, lightweight optoelectronic microscope that contains no lenses and generates a magnified video image of a specimen. The instrument was described in "Miniature...

Briefs : Photonics/Optics
Fiber-Coupled Microsphere Laser at Wavelength of 1.55 µm

The figure depicts the laboratory setup of an optical-fiber-coupled microsphere laser with an output in the 1.55-µm wavelength band used in some communication systems. This laser offers the obvious advantages of compactness and simplicity. In addition, as consequences of the high...

Briefs : Photonics/Optics
Multiple-Pump Lasers

A conceptually simple, effective scheme for reliable, high-power pumping of neodymium:yttrium aluminum garnet (Nd:YAG) lasers (and perhaps also other solid-state lasers) has been devised. Heretofore, it has been common practice to pump a Nd:YAG crystal by use of a single diode laser. However, diode lasers are not reliable...

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