June 2001

Experiments have demonstrated the feasibility of using flame-heated refractory dielectric solid bodies as wavelength-selective sources of light for special applications; in...

Arrays of photon-counting detectors and associated digital signal processors have been proposed for receivers in optical communication systems in which the optical signals...

Proposed packages called "remote engineering units" (REUs) would contain all the electronic circuitry needed to implement a subset of the design of the motor-control system of a robot....

Briefs: Photonics/Optics
Pyramid-Shape Light Coupler for Multi-Quantum-Well Photodetectors

Wavelength-independent light couplers in the form of planar arrays of pyramids have been proposed for use on multiple-quantum-well infrared photodetectors. Wavelength-independent light couplers are needed for focal-plane arrays of QWIPs designed to operate in multiple and/or...

Briefs: Motion Control
Novel Radiator for a Space Suit

An improved radiator has been designed to provide inexpensive and highly reliable thermal control for an extravehicular mobility unit (EMU) [basically, a space suit equipped with a portable life-support...

Briefs: Motion Control
Spin Bearings

Spin bearings have been invented as alternatives to such conventional rolling-element bearings as ball, spherical, needle, and roller bearings. Like a conventional bearing assembly, a spin-bearing assembly includes opposing...

A compact two-axis scanning-mirror assembly (see figure) has been developed for use as part of a laser rangefinder on a robotic vehicle. The assembly is designed to enable scanning of the laser...

Quantum-well infrared photodetectors (QWIPs) that include two-dimensional surface grating light couplers would be modified, according to a proposal to incorporate crossed slots....

The term "optical nose" refers to a fiber-optic chemical sensor of a type that has been proposed to enable distributed measurement of the concentrations of...

A compact, low-power device measures pressure via the pressure-induced damping of oscillation of a small mechanical resonator. To achieve compactness and low mass — and thus...

Briefs: Electronics & Computers
Integrated Capacitive Wheel-Contact Sensors

A low-power capacitive proximity sensor has been developed as a prototype of wheel-contact sensors for a small robotic vehicle. The sensor is integrated into a wheel and consists of only a few...

Briefs: Physical Sciences
Rare-Earth Optical Temperature Sensors

A recently developed type of fiber-optic temperature sensor utilizes narrow-band near-infrared radiation emitted by rare-earth ions. These sensors are suitable for use in harsh environments at...

Briefs: Physical Sciences
Capacitive Sensor for Measuring Level of Liquid Nitrogen

The feasibility of a capacitive sensor for measuring the level of liquid nitrogen in a container has been demonstrated. The basic sensor design could also readily be adapted to measurement of the levels of cryogenic liquids other than nitrogen.

Briefs: Electronics & Computers
Black Jack GPS Receiver

The Black Jack (BJ) receiver is the revolutionary flight Global Positioning System (GPS) receiver developed by NASA to fill future needs for orbit-based GPS science. These range from a receiver to determine precise (1-cm radial accuracy goal for JASON-1) orbits, to missions using the GPS signals for remote sensing of the...

Microelectromechanical sensors based on magnetoresistance have been proposed. Like other microelectromechanical sensors, these would be used to measure physical quantities that can be...

Digitally programmable analog membership-function circuits have been invented for use in fuzzy-logic systems. Heretofore, fuzzy membership functions have been implemented, variously,...

Briefs: Electronics & Computers
Regenerative Pseudonoise Ranging

In a proposed improved technique for pseudonoise turnaround ranging of a radio transponder, the pseudonoise modulating signal would be regenerated in the transponder. The net result of the regeneration would be an increase in the effective return ranging power. This increase would provide some margin for...

Briefs: Electronics & Computers
Biomorphic Analog Pulse-Coupled Neural Circuits

Analog electronic circuits that operate with pulsed input and output signals are undergoing development. The pulsing behavior of these circuits is modeled after a similar behavior, called...

Briefs: Electronics & Computers
Weighing Scales Based on Low-Power Strain-Gauge Circuits

Weighing scales (e.g., kitchen and bathroom scales) of a proposed type would incorporate sensory devices like the one described in "Low-Power, Microprocessor-Controlled Strain-Gauge Circuit" (NPO-19750), NASA Tech Briefs, Vol. 21, No. 1 (January 1997), page 45. Unlike other weighing scales...

Briefs: Software
Generating Maps of the Ionosphere From GPS Measurements

The Global Ionospheric Monitoring and Forecasting System (GIMSYS) computer program generates global maps of the total electron content (TEC) (electron density integrated over all altitude) of the ionosphere, maps of ionospheric irregularities, and related data byproducts. The maps are...

Briefs: Software
Program for Simulating Rotor Dynamics on Personal Computers

ARDS (Analysis of RotorDynamic Systems) is a public-domain computer program that simulates transient and steady-state dynamics of a rotary machine that can include as many as five interconnected flexible shafts. ARDS can be used to analyze the dynamics of such diverse machines as...

Briefs: Software
Software for Monitoring and Controlling DSN Operations

Network Monitor and Control (NMC) Automation Assembly (AA) is a component of the NMC software system, which is used for controlling an antenna connection in the Deep Space Network. NMC AA could also be adapted to commercial applications (e.g., chemical processing), in which human operators...

Alkoxides of lithium have been found to be useful as electrolyte additives to improve the low-temperature performance of rechargeable lithium-ion electrochemical cells. As...

Aliphatic esters have been found to be useful as electrolyte additives for improving the low-temperature performances of rechargeable lithium-ion electrochemical cells. The...

Ethyl methyl carbonate (EMC) has been found to be a suitable cosolvent, along with three other carbonate solvents, for incorporation into electrolytes to enhance the low-temperature...

Titanium disulfide has been found to be attractive as an alternative to graphite as the anode material in rechargeable lithium-ion electrochemical cells that are required to operate at...

Briefs: Manufacturing & Prototyping
Expendable Composite-Layup Dies From Rapid-Prototype Masters

A method that exploits rapid prototyping has been conceived to reduce the time and cost associated with the production of small quantities of composite-material parts that have complex shapes. In this method, mandrels and dies used in forming composite layups are sized and shaped by...

Briefs: Manufacturing & Prototyping
Punches and Dies for Rounding Corners of Metal Sheets

Punch-and-die sets have been designed for use in rounding corners of rectangular metal sheets to specified radii. One of the traditional procedures for rounding a corner on a rectangular...

Briefs: Physical Sciences
Model of Pyrolysis of Biomass in a Fluidized-Bed Reactor

A mathematical model has been formulated to describe the pyrolysis of biomass in a bubbling fluidized-bed reactor. The reactor is a vertical cylinder that contains a mixture of biomass particles and sand. Superheated steam enters the reactor through holes in the bottom and flows out freely...

Briefs: Physical Sciences
System for Delivering Gas Samples to Multiple Instruments

A system that samples gases at multiple remote locations and delivers the gases to two or possibly more gas-monitoring instruments (e.g., mass spectrometers) has been developed. The system includes a transport (suction) pump that draws the gases from the sampling locations, through...

A portable apparatus that operates at atmospheric pressure generates a beam of monatomic oxygen. The apparatus is designed to be used in a dry, noncontact process for removing...

Briefs: Physical Sciences
General-Purpose Wavelet Program

"S+Wavelets" is the name of a computer program that implements a suite of mathematical "tools" for wavelet analysis of signals (including two-dimensional signals that represent images.) Wavelets, being localized in both time and frequency (or space and wave number), serve as means for transforming and extracting...

Briefs: Information Technology
Automated Generation of Reports of Mars Rover Operations

A document describes a system for the automated generation of reports of operations of a robotic exploratory vehicle (rover) on Mars. The automated report-generation system supplants a predominantly manual system, thereby making more information available in less time and reducing the...

Filled skutterudites have shown promise as semiconducting materials with superior thermoelectric properties at temperatures up to at least 650 °C. This finding is a breakthrough in a...

Two polarization-recycling techniques have been proposed to increase the efficiency of illumination of liquid-crystal display (LCD) panels. The motivation for this proposal lies in...

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