December 1998

Stories

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Briefs: Electronics & Computers
An Internet-based software system, called the "Web Interface for Telescience" (WITS), enables geographically dispersed scientists to participate in scientific exploration of remote planets by use of...
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Briefs: Electronics & Computers
Eight-Channel WDM Fiber-Optic Data-Communication System
A proposed wavelength-division-multiplexing (WDM) optical communication system would feature a single optical fiber carrying eight channels of digital data signals. In the original application, the signal in each channel would be a serial digital video-camera output, but the system could just...
Briefs: Software
Generic Graphical-User-Interface Program for FORTRAN Input
The NLEDIT computer program implements a generic graphical user interface for the preprocessing of FORTRAN namelist input files. The interface consists of a menu system, a message window, a help system, and data-entry forms. A form is generated for each namelist. The form includes an input...
Briefs: Motion Control
When developing the guidance system of a missile, it is necessary to know the resonant frequencies and mode shapes of the missile in flight. Simulating the free vibration condition in the laboratory,...
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Briefs: Information Technology
The Multiple Object Orbital Dynamics Simulation (MOODS) computer program is a general, extensible, easily modifiable, and reusable software system for use in simulating the dynamics of...
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Briefs: Materials
The anode separators in rechargeable lithium-ion electrochemical cells that contain carbon lithium-intercalating anodes with copper current collectors would be modified, according to a...
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Briefs: Photonics/Optics
Trenches Would Reduce Cross-Talk Among Microlensed QWIPs
Cross-talk in integrated-circuit focal-plane arrays of quantum-well photodetectors (QWIPs) equipped with microlenses would be reduced, according to a proposal, by etching deep trenches into the substrates of these devices. The proposal applies, more specifically, to GaAs-based,...
Briefs: Manufacturing & Prototyping
A method to process optical fiber composed of glass systems has been developed in support of the space shuttle and Space Station programs. This process, known as the Microgravity Fiber-Pulling Apparatus, was...
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Briefs: Photonics/Optics
The performances of large focal-plane arrays of quantum-well infrared photodetectors (QWIPs) would be improved, according to a proposal, by incorporating microlenses. In comparison with a similar QWIP...
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Briefs: Photonics/Optics
Computer Code for Analysis of Stress in Silicon Wafers
The MacWafer™ code computes gravitational and thermal stresses in silicon wafers and uses these results to determine the maximum allowable temperature variation across a wafer, maximum processing temperatures, and maximum allowable heating and cooling rates. This information is of particular...
Briefs: Robotics, Automation & Control
Miniature, lightweight, low-power, low-vibration Joule-Thomson Rankine-Cycle refrigerators have been proposed for cooling portable scientific instruments. These refrigerators would be made...
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Briefs: Mechanical & Fluid Systems
An acoustic-radiation-pressure phased array (ARPPA) is undergoing development at Lewis Research Center. ARPPAs are envisioned as general-purpose, nonintrusive tools for manipulating both liquids...
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Briefs: Information Technology
Software for Qualitative Flow-Path Modeling of Systems
A computer program called "the explicit global-modeling tool" implements a dynamic method of operation by which researchers can (1) determine global flow-path changes that occur during computational simulations of the behaviors of engineering systems; (2) analyze both normal and faulty...
Briefs: Materials
More accurate analyses of adhesive EA946 can now be accomplished using new mathematical models. Tests involving this adhesive (used in the space shuttle's reusable solid-rocket-motor nozzle and other...
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Briefs: Software
Software for Analysis and Design of Turbomachinery Seals
Several computer programs, denoted collectively as the "CFD Seal Analysis Industrial Codes," have been developed to enable rapid parametric analyses and optimization of designs of a variety of turbomachinery seals. These programs could be used to design the seals that will be needed in future...
Briefs: Electronics & Computers
Quantum-well infrared photodetectors (QWIPs) that are designed to exploit transitions between bound and quasi-bound electron quantum states and that incorporate random reflectors are undergoing...
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Briefs: Photonics/Optics
A proposed miniature, electrically tunable, band-pass optical filter would have a Fabry-Perot configuration, but would be designed to trade the high spectral resolution (narrow-band pass) and...
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Briefs: Mechanical & Fluid Systems
Structural Analysis/Design (STRAND) and Neural Net Computation (NETCOM) are developmental modular computer programs that exploit the speedup afforded by parallel and neural-network...
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Briefs: Photonics/Optics
Selective Metallization for High-Temperature Semiconductors
Inventors at the Cornell Research Foundation have devised a method of selective metallization of high-temperature semiconductors to produce ohmic or rectifying contacts. The process consists of three phases: a lithographic step to define the areas of contact, preparation of the...
Briefs: Materials
A microwave-heating technique has been developed for making a braze joint (1) between a tungsten carbide support and a surface layer of polycrystalline diamond or, alternatively, (2)...
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Briefs: Information Technology
Knowledge-Based Reasoning Tool for Diagnosing a Complex Flow System
This program is designed as a real-time aid to analyze system health. The Propulsion Advisory Tool (PAT) is a knowledge-based computer program that monitors real-time data from more than 300 sensors in the space shuttle Main Propulsion System (MPS). The thermal conditions within...
Briefs: Mechanical & Fluid Systems
Acoustic-radiation pressure can be used to improve performance in the dispensing of liquid drops into gases or vacuum and in dispensing gas bubbles into liquids. In a typical application...
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Briefs: Electronics & Computers
Tracks for the guidance of magnetic bubbles propagating in the input and output lines of Vertical-Bloch-Line memory devices can be made in the form of ridges instead of in the traditional form of...
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Briefs: Manufacturing & Prototyping
The automated propellant-blending machine, a Johnson Space Center (JSC) innovation, refines the production processes of commercial rocket-propellant manufacturers by: (1) generating inert blends that...
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Briefs: Electronics & Computers
"Free-Space Optical Communications Analysis Software" (FOCAS) is the name of a spreadsheet computer program for analysis of direct-detection (as distinguished from...
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Briefs: Physical Sciences
A unique dual-flow, cold-jet facility has been developed and operated by California Polytechnic State University (Cal Poly) at San Luis Obispo for NASA Dryden Flight Research Center. The...
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Briefs: Physical Sciences
An improved miniature electrostatic sector has been designed for a miniature double-focusing mass spectrometer (see figure). Miniature mass spectrometers are essential components...
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Briefs: Mechanical & Fluid Systems
Harmonic drive gearing is recognized by designers for its zero backlash, high gear ratios, and compact design features. A recent development by HD Systems incorporates a large hollow shaft...
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