April 2003

United Space Alliance (USA) developed and used a new software development method to meet technical, schedule, and budget challenges faced...

Briefs: Physical Sciences
Turbulence in Supercritical O₂/H₂ and C₇H₁₆/N₂ Mixing Layers

This report presents a study of numerical simulations of mixing layers developing between opposing flows of paired fluids under supercritical conditions, the purpose of the study being to elucidate chemical-species- specific aspects of turbulence. The simulations were...

An improved design has been proposed for a cryostat of a type that maintains a desired low temperature mainly through boiloff of a liquid cryogen (e.g., liquid nitrogen) at...

Over the last 40 years, a series of misconceptions regarding mica capacitor applications has led novice users to consistently over- derate wound...

Briefs: Electronics & Computers
Block QCA Fault-Tolerant Logic Gates

Suitably patterned arrays (blocks) of quantum-dot cellular automata (QCA) have been proposed as fault-tolerant universal logic gates. These block QCA gates could be used to realize the potential of QCA...

Briefs: Electronics & Computers
Hybrid VLSI/QCA Architecture for Computing FFTs

A data-processor architecture that would incorporate elements of both conventional very-large-scale integrated (VLSI) circuitry and quantum- dot cellular automata (QCA) has been proposed to...

Briefs: Mechanical & Fluid Systems
Touchdown Ball-Bearing System for Magnetic Bearings

The torque-limited touchdown bearing system (TLTBS) is a backup mechanical- bearing system for a high-speed rotary machine in which the rotor shaft is supported by magnetic bearings in...

Briefs: Mechanical & Fluid Systems
Flux-Based Deadbeat Control of Induction-Motor Torque

An improved method and prior methods of deadbeat direct torque control involve the use of pulse-width modulation (PWM) of applied voltages. The prior methods are based on the use of...

Briefs: Photonics/Optics
Custom Software for Infrared Camera Image Acquisition and Control

Infrared cameras based on hybrid focal-plane array sensors are unlike consumer video products such as camcorders. They are complicated imaging devices that output very large amounts of digital image data at high speeds, require multiple levels of camera control, and produce...

Brushlike arrays of carbon nanotubes embedded in microstrip waveguides provide highly efficient (high-Q) mechanical resonators that will enable ultra-miniature radio-frequency (RF)...

Briefs: Photonics/Optics
Optical-Quality Thin Polymer Membranes

A method of fabricating both curved and flat thin polymer membranes of optical quality has been developed. The method was originally intended to enable the fabrication of lightweight membrane imaging and interferometric optics, possibly with apertures multiple meters wide, for use in scientific instruments...

Electromechanical resonators of a proposed type would comprise single carbon nanotubes suspended between electrodes (see Figure 1). Depending on the nanotube length, diameter, and...

Briefs: Software
Software for Viewing Landsat Mosaic Images

A Windows-based computer program has been written to enable novice users (especially educators and students) to view images of large areas of the Earth (e.g., the continental United States) generated from image data acquired in the Landsat observations performed circa the year 1990. The large-area...

Briefs: Software
Updated Integrated Mission Program

Integrated Mission Program (IMP) is a computer program for simulating spacecraft missions around the Earth, Moon, Mars, and/or other large bodies. IMP solves the differential equations of motion by use of a Runge-Kutta numerical-integration algorithm. Users control missions through selection from a large menu...

Briefs: Software
Software for Sharing and Management of Information

DIAMS is a set of computer programs that implements a system of collaborative agents that serve multiple, geographically distributed users communicating via the Internet. DIAMS provides a user interface as a Java applet that runs on each user’s computer and that works within the context of the...

Briefs: Software
Update on Integrated Optical Design Analyzer

Updated information on the Integrated Optical Design Analyzer (IODA) computer program has become available. IODA was described in “Software for Multidisciplinary Concurrent Optical Design” (MFS-31452), NASA Tech Briefs, Vol. 25, No. 10 (October 2001), page 8a. To recapitulate: IODA facilitates...

A method of manufacturing regular arrays of precisely sized, shaped, positioned, and oriented carbon nanotubes has been proposed. Arrays of carbon nanotubes could prove useful in...

A precision piezoelectric positioning system with high-bandwidth and high-power enables a new class of precision machining called Vibration Assisted Machining. The actuator and...

Folded horns have been conceived as alternatives to straight horns used as resonators and strain amplifiers in power ultrasonic systems. Such systems are used for cleaning, welding,...

An experiment and calculation have demonstrated the feasibility of a technique of compact storage of paraboloidal mirrors made of thin composite-material (multiple layers of carbon...

Briefs: Mechanical & Fluid Systems
Cellular Pressure-Actuated Joint

A modification of a pressure-actuated joint has been proposed to improve its pressure actuation in such a manner as to reduce the potential for leakage of the pressurizing fluid. The specific joint for which...

Briefs: Mechanical & Fluid Systems
Force-Measuring Clamps

Force-measuring clamps have been invented to facilitate and simplify the task of measuring the forces or pressures applied to clamped parts. There is a critical need to measure clamping forces or pressures in some applications — for example, while bonding sensors to substrates or while clamping any sensitive or delicate...

Briefs: Mechanical & Fluid Systems
Multiple-Use Mechanisms for Attachment to Seat Tracks

A Seat Track Attach Mechanism (SAM) is a multiple-use clamping device intended for use in mounting various objects on the standard seat tracks used on the International Space Station...

A relatively simple, manually operated tool enables precise bending (typically, within ±1/2° of the specified bend angle) of a metal tube located in a confined space, with a...

Briefs: Medical
Time-Resolved Measurements in Optoelectronic Microbioanalysis

A report presents discussion of time-resolved measurements in optoelectronic microbioanalysis. Proposed microbioanalytical "laboratory-on-a-chip" devices for detection of microbes and toxic chemicals would include optoelectronic sensors and associated electronic circuits that would...

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