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...

Briefs : Physical Sciences
Throttling Cryogen Boiloff To Control Cryostat Temperature

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 atmospheric pressure. (A cryostat that maintains a low temperature mainly through boiloff of a cryogen at...

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...

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 steady-state normal operation. The TLTBS provides ballbearing support to augment or supplant the magnetic...

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 stator flux and stator current as state variables, leading to mathematical solutions of control equations in...

Briefs : Mechanical & Fluid Systems
Piezoelectric Positioning Enables Vibration Assisted Machining

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 drive electronics optimize stroke, stiffness and dynamic response of the diamond tool.

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...

Briefs : Photonics/Optics
Arrays of Carbon Nanotubes as RF Filters in Waveguides

Brushlike arrays of carbon nanotubes embedded in microstrip waveguides provide highly efficient (high-Q) mechanical resonators that will enable ultra-miniature radio-frequency (RF) integrated circuits. In its basic form, this invention is an RF filter based on a carbon nanotube array...

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...

Briefs : Photonics/Optics
Carbon Nanotubes as Resonators for RF Spectrum Analyzers

Electromechanical resonators of a proposed type would comprise single carbon nanotubes suspended between electrodes (see Figure 1). Depending on the nanotube length, diameter, and tension, these devices will resonate at frequencies in a range from megahertz through gigahertz. Like the...

Briefs : Medical
Growth Conditions To Reduce Oxalic Acid Content of Spinach

A controlled environment agricultural (CEA) technique to increase the nutritive value of spinach has been developed. This technique makes it possible to reduce the concentration of oxalic acid in spinach leaves. It is desirable to reduce the oxalic acid content because oxalic acid acts...

Briefs : Medical
Hydrofocusing Bioreactor for Three-Dimensional Cell Culture

The hydrodynamic focusing bioreactor (HFB) is a bioreactor system designed for three-dimensional cell culture and tissue-engineering investigations on orbiting spacecraft and in laboratories on Earth. The HFB offers a unique hydrofocusing capability that enables the creation of a...

Briefs : Electronics & Computers
Signal-Conditioning Amplifier Recorders

Signal-conditioning amplifier recorders (SCAmpRs) have been proposed as a means of simplifying and upgrading the Kennedy Space Center (KSC) Ground Measurement System (GMS), which is a versatile data-acquisition system that gathers and records a variety of measurement data before and during the launch of a...

Briefs : Electronics & Computers
SpaceWire Driver Software for Special DSPs

A computer program provides a high-level C-language interface to electronics circuitry that controls a SpaceWire interface in a system based on a space qualified version of the ADSP-21020 digital signal processor (DSP). SpaceWire is a spacecraft-oriented standard for packet-switching data-communication...

Briefs : Electronics & Computers
Nanoconverters for Powering Nanodevices

Proposed integrated-circuit modules called "nanoconverters" would derive DC power from impinging electromagnetic beams having frequencies in the terahertz range. Nanoconverters are composed of microscopic antennas and diodes (see Figure 1) resembling rectennas that have been developed to perform the same...

Briefs : Electronics & Computers
Contactless Rotary Electrical Couplings

Rotary electrical couplings based on induction (transformer action) rather than conduction between rotating and stationary circuitry have been invented. These couplings provide an alternative to slip rings and contact brushes.

Mechanical imperfections of slip-ring and brush contact surfaces and/or...

Briefs : Electronics & Computers
MOS Circuitry Would Detect Low-Energy Charged Particles

Metal oxide semiconductor (MOS) circuits for measuring spatially varying intensities of beams of low-energy charged particles have been developed. These circuits are intended especially for use in measuring fluxes of ions with spatial resolution along the focal planes of mass spectrometers....

Briefs : Electronics & Computers
Software for Remote Monitoring of Space-Station Payloads

Telescience Resource Kit (TReK) is a suite of application programs that enables geographically dispersed users to monitor scientific payloads aboard the International Space Station (ISS). TReK provides local ground support services that can simultaneously receive, process, record,...

Briefs : Electronics & Computers
Relating Downlink Data Products to Uplink Commands

An improved data-labeling system provides for automatic association of data products of an exploratory robot (downlink information) with previously transmitted commands (uplink information) that caused the robot to gather the data. Such association is essential to correct and timely analysis of...

Briefs : Mechanical & Fluid Systems
Accurate Spring Testing

Virtually all spring manufacturers must test their products with some kind of load testing machine. Testing ensures that the product is produced and shipped within the customer's specifications. Or does it? Disputes over test results still occur that can cause a multitude of costly problems: returned product, delayed...

Briefs : Mechanical & Fluid Systems
Compliant Gripper for a Robotic Manipulator

The figure depicts a prototype of a robotic-manipulator gripping device that includes two passive compliant fingers, suitable for picking up and manipulating objects that have irregular shapes and/or that are, themselves, compliant. The main advantage offered by this device over other...

Briefs : Mechanical & Fluid Systems
Hybrid Aerial/Rover Vehicle

A proposed instrumented robotic vehicle called an "aerover" would fly, roll along the ground, and/or float on bodies of liquid, as needed. The aerover would combine features of an aerobot (a robotic lighter-than-air balloon) and a wheeled robot of the "rover" class. An aerover would also look very...

Briefs : Manufacturing & Prototyping
Tool For Friction Stir Tack Welding of Aluminum Alloys

A small friction-stir- welding tool has been developed for use in tack welding of aluminum-alloy workpieces. It is necessary to tack-weld the workpieces in order to hold them together during friction stir welding because (1) in operation, a full-size friction-stir-welding tool exerts a large...

Briefs : Manufacturing & Prototyping
Improving Plating by Use of Intense Acoustic Beams

An improved method of selective plating of metals and possibly other materials involves the use of directed high-intensity acoustic beams. The beams, typically in the ultrasonic frequency range, can be generated by fixed- focus transducers (see figure) or by phased arrays of transducers excited,...

Briefs : Information Technology
Integrated Formulation of Beacon-Based Exception Analysis for Multimissions

Further work on beacon-based exception analysis for multimissions (BEAM), a method of real-time, automated diagnosis of a complex electromechanical systems, has greatly expanded its capability and suitability of application. This expanded formulation, which fully...

Briefs : Information Technology
Self-Supervised Dynamical Systems

Some progress has been made in a continuing effort to develop mathematical models of the behaviors of multi- agent systems known in biology, economics, and sociology (e.g., systems ranging from single or a few biomolecules to many interacting higher organisms). This effort at an earlier stage was reported in...

Briefs : Information Technology
Software for Better Documentation of Other Software

The Literate Programming Extraction Engine is a Practical Extraction and Reporting Language- (PERL-) based computer program that facilitates and simplifies the implementation of a concept of self- documented literate programming in a fashion tailored to the typical needs of scientists. The...