A surface-micromachining process has been devised for use in fabricating microscopic polycrystalline diamond structures (e.g., bridges and cantilevers) as integral...

Briefs: Electronics & Computers
Prolonging the Lives of Rechargeable Lithium-Ion Cells

Several modifications of the design and operation of lithium-ion rechargeable electrochemical cells have been proposed to prolong the cycle lives of the cells. As explained below, overdischarge can result in dissolution of a metal current collector in the anode of a cell, with consequent...

A prototype mixer designed for operation at input frequencies near 2.5 THz incorporates a planar Schottky-barrier diode and a radio-frequency (RF) filter that are parts of an integrated...

Reflective flat-panel color display devices based on surface plasmons are undergoing development. Heretofore, no reflective flat-panel color display devices have been available. The active...

Briefs: Materials
Nonchromic Acid Brightener for Brass and Copper

A process for precleaning brass and copper parts before processing them further in a clean room includes a brightening chemical treatment in solution of 85 volume percent phosphoric acid, 3 volume percent nitric acid, and 12 volume percent acetic acid. This solution acts rapidly and can be...

Briefs: Physical Sciences
Shape-Memory-Alloy Thermal-Conduction Switches

Variable-thermal-conduction devices containing shape-memory-alloy (SMA) actuators have been proposed for use in situations in which it is desired to switch on (or increase) thermal conduction when temperatures rise above specified values and to switch off (or decrease) thermal conduction when...

Surface-plasmon tunable filters (SPTFs) have been proposed for use in generating scrolling colors on the faces of liquid-crystal display (LCD) devices. In comparison with a...

Briefs: Electronics & Computers
Desktop Computer System Processes Satellite Data

The Desktop Satellite Data Processor (DSDP) is a prototype computer system for processing telemetry data received from, and command data to be transmitted to, a spacecraft in orbit around the...

Briefs: Mechanical & Fluid Systems
Analysis of Flutter of the APEX Sailplane

This airplane is expected to be safe from destruction by flutter instabilities.

Briefs: Photonics/Optics
Video-Based Foreign Object Detection

The Boeing Company has developed an overhead camera system that can automatically spot small pieces of debris on a work surface that might otherwise go unnoticed. The system automatically analyzes inputs...

A prototype Stirling-engine regenerator containing a matrix made of carbon-fiber-based composite materials has been developed. The concept underlying this development effort is one of...

Briefs: Electronics & Computers
Fabry-Perot Fiber-Optic Temperature Sensor

A class of developmental photonic temperature-measuring systems is based on the use of miniature, fiber-optic-coupled Fabry-Perot interferometers as temperature transducers. These systems are...

Briefs: Electronics & Computers
Luneberg Lenses Made of Open-Cell Polyurethane Foams

A Luneberg lens is a microwave lens consisting of a series of concentric shells of differing dielectric constants. The highest dielectric constant, or refractive index, resides at the core and the lowest, at the outer shell. Microwaves passing through this arrangement of shells are focused in...

Integrated electrochemical sensors are being developed for use in measuring concentrations of sulfur dioxide in gas mixtures. These sensors are based on the electrochemical oxidation of...

Briefs: Electronics & Computers
Dual-Function Microelectronic Sensors

Integrated-circuit image sensors of a proposed type would be capable of operation in either the wavelength band of 0.5 to 2.5 *m, the wavelength band of 2.8 to 5.8 *m, or both bands simultaneously....

Briefs: Software
Program Simulates Performance of a Hybrid Automobile

The Hybrid Electric Vehicle Analysis (HEVA) computer program numerically simulates the performance of an automotive vehicle -- especially a hybrid vehicle. A vehicle is said to be hybrid if (1) it contains an energy-storage device (a battery, flywheel, or ultra-capacitor) that is charged with...

An algorithm that processes bursts of data generated by scan-mode synthetic-aperture radar (scanSAR) offers some advantages over older scanSAR algorithms. With relatively high computational...

Briefs: Physical Sciences
Experiments on Flow in a Model Compressor Drum

A report discusses experiments on the flow of water along the interior of a transparent rotating cylindrical drum, the interior of which was partitioned into five cavities by disks with central holes and outer edges attached to the cylindrical drum wall. This water-flow model was designed to provide...

Improved silicon carbide-based Schottky diodes are undergoing development for use in detecting hydrocarbon (CxHy) and nitrogen oxide (NOx) gases at...

The figure shows a tension/compression structure that provides rigid suspension and a high degree of thermal isolation for a small instrument assembly used in low-temperature...

Briefs: Mechanical & Fluid Systems
Flutterometer for Flight Testing

A flutterometer is being developed for use as a data-analysis tool for flight flutter testing. The tool is based on an on-line implementation of a robust flutter-analysis technique, called the "* method,"...

Fiber-optic transceivers (FOTs) that can handle digital signals at any bit rate from 10 to 300 MHz have been developed. These variable-rate FOTs offer considerable advantages over fixed-rate FOTs that...

An alloy of 88Cu/8Cr/4Nb (numbers indicate atomic percentages) has been proposed for use in fabricating rocket-engine combustion chambers by vacuum plasma spraying (VPS). Relative...

Briefs: Physical Sciences
Electrostrictive Thermal Break Between Superfluid Reservoirs

A proposed technique would make it possible to maintain two reservoirs of superfluid helium at the same pressure but at different temperatures. Heretofore, a fountain effect (described below) has made this impossible. The proposed technique could be useful for low-temperature...

Briefs: Mechanical & Fluid Systems
Model of Response of Pressure Sensor in Rarefied Flow

A mathematical model represents the dynamic response of a pressure sensor that (a) comprises a transducer connected to a pressure-sensing port via a pneumatic tube and (b) is operated...

Briefs: Physical Sciences
In Situ Chemical Analysis via Acoustic-Emission Spectra

A method of in situ chemical analysis by use of small, simple, robust sensors has been proposed. The basis for the proposal is the discovery that chemical reactions emit acoustic waves, and that characteristic frequency spectra are associated with specific reactions. The acoustic...

The Multi-Board Module (MBM) scheme has been conceived to provide a cost-effective way to combine digital electronic circuits into dense, lightweight packages, within which high-speed...

Improved pulsed inductive plasma accelerators are undergoing development for use as long-life thrusters for propulsion of spacecraft on interplanetary missions and for maneuvering...

A noninvasive medical-imaging system produces false-color images that show regions of ischemia (reduced oxygenated blood flow) in organs and tissues. The system operates in real time, providing immediate...

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