Briefs : Physical Sciences
Assessing Energetic-Ion Effects Using Energetic Protons Only

Two reports describe a method of assessing the susceptibility of digital electronic equipment to upsets (bit errors) caused by impingement of energetic ions (both protons and heavier ions) in outer space.

The method, which is applicable at the single-component, circuit-board,...

Briefs : Electronics & Computers
System Would Detect Aircraft to Turn Off Upward-Aimed Laser

An electronic system based on long-wavelength infrared (LWIR) sensors is being developed to detect aircraft flying near an upward-aimed, high-power laser beam. In the intended application, the system would alert a human laser operator and/or generate a signal to turn off the laser...

Briefs : Physical Sciences
Simplified Achromatic Nulling Beam Combiner

The figure schematically depicts a proposed achromatic nulling beam combiner. This instrument is intended for use in astronomy - principally, for attenuating light from stars or other bright sources in order to enable detection of fainter objects that lie near the bright sources. In comparison with a...

Briefs : Photonics/Optics
Low-Loss, High-Extinction-Ratio Polarizer

An improved optical polarizer has been proposed for use with a high-energy pulsed laser. This polarizer would separate the p- and s-polarized components (the components polarized parallel and perpendicular, respectively, to a designated plane or axis) of an incoming beam of light into two outgoing beams...

Briefs : Photonics/Optics
Rugged Laser-Diode Oxygen Sensor

A rugged laser-diode oxygen sensor is being developed for detecting leaks of oxygen from diverse systems, including rocket engines, cryogenic systems, and medical equipment. The sensor is required to have a range of 250 to 250,000 parts per million, to be accurate within 5 percent, to be capable of operating at...

Briefs : Photonics/Optics
Thermography Using YVO₄:Dy³⁺

A proposed thermographic technique would exploit the unique fluorescence characteristics of yttrium vanadate doped with dysprosium (YVO4:Dy3+). The particular aspect of the fluorescence characteristics that would be exploited in this technique is the relative intensity of emitted light as a...

Briefs : Materials
Carbon-Composite Heat-Sinking Submounts for Laser Diodes

Carbon-composite submounts tipped with diamond are being developed as improved means of dissipating heat generated in high-power laser diodes. Copper is the traditional heat-sinking material for many applications other than laser diodes; it is not suitable for heat-sinking submounts for...

Briefs : Physical Sciences
Estimating White-Light-lnterferometer Phases in Dim Light

A method has been developed to increase the accuracy of estimates of phase differences attributable to the optical-path-length difference between the arms of a long-baseline, white-light interferometer. The method is intended for use in the Space Interferometer Mission (SIM), in which...

Briefs : Electronics & Computers
Semiconductor Quantum Dots as Radiation-Hard Light Emitters

Light-emitting devices based on semiconductor quantum dots have been shown to be suitable for use in environments that include high levels of radiation that causes displacement damage in semiconductors - in particular, energetic protons. Conventional light-emitting diodes and other...

Briefs : Photonics/Optics
Optical-Based Method for Characterizing Protein Crystals

A method of characterization of growing of protein crystals involves the utilization of an optical imaging technique known as spatial phase imaging. The methods used heretofore have been, variously, invasive (e.g., adding a dye that is absorbed by the protein of interest), destructive...

Briefs : Software
Embeddable Fuzzy-Logic-Toolkit Software for Tcl/Tk

A computer program of the fuzzy-logictoolkit type has been devel- oped as a relatively simple, portable, highly compatible, means of providing fuzzy-logic reasoning capabilities for control and expert-system applications.

This program is designed to work with the high-level scripting language...

Briefs : Software
Program Analyzes Use of Registers by Another Program

Regprof is a computer program that analyzes the use of registers by another program that runs on a PowerPC

750 (or equivalent) computer. Regprof is useful for showing how well compilers make use of registers and for obtaining an indication of the susceptibility of application programs...

Briefs : Software
Real-Time Desktop Manager

Real-time Desktop Manager (RDM) is a computer program that manages displays and application programs. RDM was developed for use in connection with NASA’s remote manipulator system (RMS) group of flight controllers; it could also be used in chemical plants, laboratories, factories, hospitals, and other settings where...

Briefs : Electronics & Computers
FQPSK With an Outer Code for Greater Efficiency

A proposed method of FQPSK modulation and demodulation of a radio signal would incorporate any of a number of relatively simple (short-constraintlength) outer codes. By affording significant coding gains even when using a reduced-complexity (and thus suboptimal) FQPSK receiver, this method would...

Briefs : Electronics & Computers
Noncontact Scanning Surface Profilometers

A class of optoelectronic noncontact computer-controlled scanning surface profilometers is undergoing development for use in automated or semiautomated in- spection of nominally flat surfaces. When fully developed, these profilometers would generate three-dimensional maps of the scanned surfaces for...

Briefs : Electronics & Computers
Intuitive Control System for a Dexterous Robot

The Full Immersion Telepresence Testbed (FITT) is an experimental anthropomorphic-robot remote-control system that is so named because it gives a human control operator some of the sensations of the remote environment as though the operator were in that environment in place of the robot. In...

Briefs : Information Technology
Initialized Fractional Calculus

The fractional calculus (which admits of integrals and derivatives of non-integer order) dates back almost to the origin of the better-known ordinary (integer-order) calculus, but thus far has been treated more as a mathematical curiosity than as a scientific and engineering tool. Increasingly many physical...

Briefs : Electronics & Computers
Ultrasonic System Tracks Body Movements in Three Dimensions

A system based on ultrasonic sensors has been developed as a means of tracking moving objects with centimeter accuracy. The system is intended especially for tracking pertinent parts of the body of a human subject engaged in control of a remote anthropomorphic robot or immersed in a...

Briefs : Mechanical & Fluid Systems
Cylindrical Shape-Memory Rotary/Linear Actuator

A compact actuator generates rotary or linear motion with a large torque or force, respectively. The original version of this actuator is designed to pull a wedge that, until pulled, prevents retraction of the proposed extended nose landing gear of the space shuttle. The original version is also...

Briefs : Software
Program Finds Target-Chemical Signals in Multisensor Outputs

A computer program deconvolves the digitized outputs of multiple chemical sensors in an array to extract indications of the identities and con- centrations of target chemicals (which could be individual compounds or specified mixtures of compounds). Chemical-sensor arrays — denoted,...

Briefs : Test & Measurement
Pressure-Application Device for Testing Pressure Sensors

A portable pressure-application device has been designed and built for use in testing and calibrating piezoelectric pressure transducers in the field. The device generates pressure pulses of known amplitude. A pressure pulse (in contra- distinction to a steady pressure) is needed because...

Briefs : Physical Sciences
Slab-Waveguide Interferometer for Sensing Ammonia in Wet Air

The figure depicts a single-arm, slabwave- guide interferometer that has been demonstrated to be useable as a means of sensing ammonia in wet air. The slabwaveguide portion of this device comprises a 2-μm-thick film of poly(methyl methacrylate) [PMMA] on a substrate of fused quartz....

Briefs : Software
Program Computes Outer-Space Heat-Sink Temperatures

TSCALC is a computer program that calculates the space sink temp- erature (TS), defined as the equilibrium temp- erature of a spacecraft heat-dissipation radiator or other object nominally isolated except for radiative exchange of heat with the Sun, or any star for which equilibrium...

Briefs : Materials
Ablative Coat Protects Against Brief, Intense Heating

An ablative composite coating has been developed to protect a steel substrate against a short-duration exposure to supersonic stream of hot gases and molten ceramic particles. In the original application, the short-duration hot, abrasive flow is resultant from the shuttle solid-fuel rocket...

Briefs : Materials
Insertion of Reactive Material for Treating Groundwater

An improved method of inserting reactive material in the ground for treating groundwater contaminated with chlorinated solvents has been devised. An older method involves the removal of a significant portion of soil overlying the treatment volume, and consequently the expensive off-site...

Briefs : Mechanical & Fluid Systems
Formation Alignment of Multiple Autonomous Vehicles

A table-top experiment on formation alignment of three air-levitated robotic vehicles has been performed to demonstrate the feasibility of a more general concept of controlling multiple robotic vehicles to make them move in specified positions and orientations with respect to each other. The...

Briefs : Mechanical & Fluid Systems
Microfabricated Flow Controllers and Pressure Regulators

Efforts are underway to develop microfabricated flow controllers and pressure regulators that contain as few discrete components as feasible and that are cheaper, more robust, and orders of magnitude smaller than are currently commercially available devices that have similar capabilities....

Briefs : Manufacturing & Prototyping
Growing Carbon Nanotubes Aligned With Patterns

A process has been proposed for growing carbon nanotubes aligned substantially parallel with the nominal planar surfaces of substrates and further aligned with patterns on the substrates. Prior to growth, the patterns would be formed by micromachining the substrates, which could be silicon or...

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