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Briefs: Physical Sciences
Solitons on WDM Beams in a Nonlinear Optical Fiber
This paper sets the ultimate limit on the maximum amount of optical data pulses that can be sent through a single fiber in a given period under the wavelength-division-multiplexed (WDM) format. The discovery in 1973 that optical soliton on a single wavelength beam can exist in fiber is one of...
Briefs: Information Technology
Fast Observers for Spacecraft Pointing Control
A report discusses the design of fast stochastic observers for spacecraft pointing control. In this special context, "observers" signifies mathematical algorithms, implemented on computers aboard spacecraft, through which one processes sensory data (principally, the outputs of star trackers and...
Briefs: Materials
Nesting-Hoop Solar Sail
A report discusses a proposed nesting-hoop solar sail that would be used to propel a spacecraft on a deep-space mission. The nesting-hoop design concept was chosen as one that would afford a desired combination of small mass and compact stowage during launch. The sail would include multiple disks, each comprising a thin...
Briefs: Electronics & Computers
The Parallel Integrated Frame Synchronizer (PIFS) chip is one of three very-large-scale integrated (VLSI) circuits designed for ground processing of streams of telemetric data received from...
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Briefs: Electronics & Computers
An advanced complementary metal oxide/semiconductor (CMOS) active-pixel sensor (APS) incorporates integrated circuitry that computes the centroid of the image in a window selectable by the...
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Briefs: Manufacturing & Prototyping
Software for Designing Plasma Reactors for Microelectronics
Outer-space plasmas and arc-jet plasmas are well known to many researchers at NASA. Efforts to understand the structures of these plasmas have consumed years of research at various NASA laboratories. Computational modeling of such plasmas involves analyses of multicomponent,...
Briefs: Manufacturing & Prototyping
Writing Circuit Patterns by Use of Scanning UV Lasers
Scanning ultraviolet (UV) lasers would be used to expose ultraviolet-sensitive photoresists to form patterns of conductors for electronic circuits, according to a proposal. Heretofore, such patterns have been formed by exposing photoresists to collimated ultraviolet or visible light through...
Briefs: Mechanical & Fluid Systems
A Rankine-cycle engine that contains a binary working fluid (ammonia + water) and a recuperative heat exchanger has been built and tested. This engine is a prototype of "bottoming"-cycle...
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Briefs: Photonics/Optics
A technique of parallel-beam interferometry with spatially incoherent light has been proposed to solve two problems that arise in conjunction with using interferometry to measure the shape of...
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Briefs: Photonics/Optics
A method of correcting for the distorting effects of the atmosphere upon a laser beam used in free-space optical communication has been proposed. The original version of the method...
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Briefs: Photonics/Optics
Improved Optical Fallout Monitor
Modifications have been made to upgrade the system described in "Optoelectronic Particle-Fallout Sensor" (KSC-11687), NASA Tech Briefs, Vol. 19, No. 4 (April 1995), page 17a. A description of the unmodified version of the system is necessary to place a description of the modifications in context:
Briefs: Photonics/Optics
In a proposed method for rapidly detecting hydrazine in air at concentrations at or above 10 parts per billion by volume (ppbv), tunable diode lasers (TDLs) and photodetectors would be used...
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Briefs: Photonics/Optics
A proposed electro-optical apparatus would shift the frequency of a laser beam by a controllable amount within the range of about ±10 GHz. It would be a wide-band alternative to an acousto-optical tunable...
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Briefs: Photonics/Optics
Plasma spraying has been shown to be an effective means of depositing thin films of various oxides for use as wavelength-selective emitters for thermophotovoltaic devices (see Figure...
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Briefs: Electronics & Computers
A class of developmental asymmetric electrochemical capacitors is based on (1) nonpolarizing positive electrode made of nanotructured γ-MnO2, (2) aqueous electrolyte , and (3)...
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Briefs: Physical Sciences
The Atmospheric Electron X-ray Spectrometer (AEXS) is being developed for performing rapid, nondestructive in situ analyses of the elemental composition of surfaces. The capability of the AEXS to operate...
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Briefs: Electronics & Computers
Locally Connected Neural Networks for Pattern Recognition
Neural networks of a proposed type would be formed with computational units called "neuromorphs" attached in a locally connected array. These neural networks would achieve pattern recognition invariant under rotation and translation by exploiting a combination of network symmetry and...
Briefs: Electronics & Computers
Cross-Correlated Trellis-Coded Quadrature Modulation
Cross-correlated trellis-coded quadrature modulation (XTCQM) has been proposed as a generic scheme with specific embodiments that potentially offer superior alternatives to other highly power- and bandwidth-efficient phase-shift-keying (PSK) modulation schemes. Examples of such schemes include...
Briefs: Test & Measurement
The development of miniature, cold- gas thrusters for on-orbit propulsion of such small devices as remotely piloted cameras and for inclusion in astronaut propulsion backpacks gave rise to a need to measure...
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Briefs: Test & Measurement
Software for Designing Model Rockets for Base-Heating Tests
The Impulse Combustion Excel (ICE) computer program was developed to facilitate and accelerate the design and analysis of subscale rocket engines for use in base-heating tests. Such tests are performed on the ground to obtain data for estimating the heating effects of hot exhaust plumes on...
Briefs: Software
Software for Analysis of Contamination of the ISS
The NASAN computer program can perform detailed analyses of molecular column density and molecular deposition on and around such complex space structures as the International Space Station (ISS). Contamination from both point sources (e.g., thrusters and vents) and diffuse sources (e.g., reflected...
Briefs: Materials
A program of research and development is addressing the feasibility of using magnetoplasmadynamic (MPD) sources in the chemical vapor deposition (CVD) of synthetic diamond films. Because of its...
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Briefs: Energy
Oxygen Batteries Based on a Solid Polymer Electrolyte
Scientists have developed a derivative of the lithium-ion cell that could prove useful in spaceflight and commercial applications in which it is planned to use oxygen batteries based on solid polymer electrolytes. This derivative cell, which contains a solid polymer electrolyte and an oxygen gas...
Briefs: Physical Sciences
Submillimeter-sized, transparent, solid, truncated spheres and ellipsoids for use as optical resonators in integrated microphotonic devices would be made by microfabrication...
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Briefs: Information Technology
A methodology of computer-aided planning has been developed to (1) accelerate the generation of plans for activities within complex systems of personnel and equipment; (2) increase the...
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Briefs: Information Technology
Electronic Time-Card System
A computer-based automated system has been developed to replace a cumbersome and error-prone paper-based system for recording employees' work times. The automated system minimizes the consumption of paper and eliminates the need for weekly pick-up and delivery of time sheets throughout the Kennedy Space Center. The...
Briefs: Medical
An improved stretching device has been developed for use in research on the effects of unidirectional loading on human and animal cells. The device is capable of applying or removing a load (a...
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Briefs: Manufacturing & Prototyping
Small, temporary, disposable inserts, called "gap welding preforms," have been proposed for use in attaching electrically conductive ribbons to radio-frequency (RF) electronic circuits. As explained below, the use of gap...
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Briefs: Medical
Figure 1 schematically illustrates a laboratory apparatus that provides quantitative information on the density and on the rate of increase (or decrease) of density at which bacteria...
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