A comprehensive library of technical briefs from engineering experts at NASA and major government, university, and commercial laboratories covering all aspects of innovations in electronics, software, photonics, imaging, motion control, automation, sensors, test, materials, manufacturing, mechanical, and mechatronics.

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...

The Boeing Company has developed wavelet-based image compression software that offers state-of-the-art compression of still imagery, providing superior image quality at compression ratios ranging from...

An ultrasonic-transducer fixture containing multiple pairs of fixed transducers, plus associated electronic transducer-multiplexing circuitry have been developed to accelerate the acquisition...

Briefs: Electronics & Computers
Solar-Cell System With High Conversion Efficiency

A concept for obtaining high energy-conversion efficiency in a solar photovoltaic system involves (1) concentration and spectral dispersion of sunlight and (2) use of several types of solar...

Briefs: Mechanical & Fluid Systems
Improved Mufflers for General Aviation

Innovative designs of mufflers for engines of small airplanes have been investigated in an effort to satisfy conflicting demands to maximize the reduction of exhaust noise while minimizing back pressure, size, and weight. Automotive-type muffler designs are not suitable for this purpose because they entail...

Briefs: Photonics/Optics
Dielectric Coating Grading Method

In a filing before the U.S. Patent and Trademark Office, the Boeing Company has disclosed a post-processing method for dielectric combiner elements that may reduce the cost of grading dual combiner sets by...

Briefs: Materials
Etching Solution for Removal of Silver Plating From Polymers

An etching solution has been developed for use in removal of silver plating from polymer-based (including composite-material) structural components, the surfaces of which are intended to serve as mirrors and waveguide structures. Such structures are often plated with aluminum, copper,...

Briefs: Robotics, Automation & Control
Performance of an Arc-Jet Thruster

A report discusses the design and testing of a laboratory-model arc-jet thruster designed to operate at a nominal power level of 300 W. This thruster is an intermediate product of continuing efforts to develop smaller, lower-power, higher-specific-impulse thrusters for use in a forthcoming generation of small...

Briefs: Medical
Neutrophil-Screening Assay Using Two-Color Flow Cytometry

An in vitro test that includes the use of two-color flow cytometry has been developed for use in screening of neutrophils for their ability to fight infections. Neutrophils constitute the first line of defense of the human body against infections. Neutrophils engulf invading bacteria in a...

An optical technique for measuring the concentration of soot in air is based on the cavity-ring-down (CRD) principle, which is so named because it involves observation of the decay...

Briefs: Information Technology
The SPEEDES Qheap: A Priority-Queue Data Structure

The Synchronous Parallel Environment for Emulation and Discrete-Event Simulation (SPEEDES) is now using a new general-purpose priority queue data structure called the SPEEDES Qheap for managing its set of pending events in ascending time order. Empirical studies have shown this data structure to...

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....

An improved miniature electrostatic sector has been designed for a miniature double-focusing mass spectrometer (see figure). Miniature mass spectrometers are essential...

Briefs: Mechanical & Fluid Systems
Hollow Shaft Actuators with Harmonic Drive Gearing

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...

Briefs: Electronics & Computers
Update on the Web Interface for Telescience

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...

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...

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...

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...

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