Topics

Physical Sciences

Stories

6
-1
1290
30
Briefs: Physical Sciences
An improved cryostat has been developed for cooling a wide panel evenly over its surface to a temperature of -423 °F (≈-253 °C) by use of liquid helium. Originally, the cryostat was to be used in...
Feature Image
Briefs: Physical Sciences
Waste-Heat-Driven Cooling Using Complex Compound Sorbents
Improved complex-compound sorption pumps are undergoing development for use as prime movers in heat-pump systems for cooling and dehumidification of habitats for humans on the Moon and for residential and commercial cooling on Earth. Among the advantages of sorption heat-pump systems are...
Briefs: Physical Sciences
The pseudoslit spectrometer is a conceptual optoelectronic instrument that would offer some of the advantages, without the disadvantages, of prior linear- variable etalon (LVE) spectrometers and prior slit spectrometers....
Feature Image
Briefs: Physical Sciences
Filament-wound composites are replacing metals as the material of choice for tanks to hold liquids and gases. The composites have a high strength-to- weight ratio, making them...
Feature Image
Briefs: Physical Sciences
Solution-Assisted Optical Contacting
A modified version of a conventional optical-contact procedure has been found to facilitate alignment of optical components. The optical-contact procedure (called simply "optical contacting" in the art) is a standard means of bonding two highly polished and cleaned glass optical components without using epoxies...
Briefs: Physical Sciences
A mathematical model of a three-dimensional mixing layer laden with evaporating fuel drops composed of many chemical species has been derived. The study is motivated by the fact that...
Feature Image
Briefs: Unmanned Systems
In the summer of 2001, the Helios prototype solar-powered uninhabited aerial vehicle (UAV) [a lightweight, remotely piloted airplane] was deployed to the Pacific Missile Range Facility...
Feature Image
Briefs: Physical Sciences
Electrochemical, H₂O₂-Boosted Catalytic Oxidation System
An improved water-sterilizing aqueous-phase catalytic oxidation system (APCOS) is based partly on the electrochemical generation of hydrogen peroxide (H2O2). This H2O2-boosted system offers significant improvements over prior dissolved-oxygen water-sterilizing systems in the way in which...
Briefs: Physical Sciences
Permanent Sequestration of Emitted Gases in the Form of Clathrate Hydrates
Underground sequestration has been proposed as a novel method of permanent disposal of harmful gases emitted into the atmosphere as a result of human activity. The method was conceived primarily for disposal of carbon dioxide (CO2, greenhouse gas causing global warming), but...
Briefs: Energy
Cube-shaped thermoelectric devices energized by a particles from radioactive decay of 244Cm have been proposed as long-lived sources of power. These power cubes are intended especially for...
Feature Image
Briefs: Physical Sciences
An ultraviolet-absorption spectrometer system has been developed as a prototype instrument to be used in continuous, real-time monitoring to detect the growth of biofilms. Such monitoring is...
Feature Image
Briefs: Physical Sciences
The StarLight Space Interferometer
Two papers describe the StarLight space interferometer — a Michelson interferometer that would be implemented by two spacecraft flying in formation. The StarLight formation flying interferometer project has been testing and demonstrating engineering concepts for a new generation of space interferometers that...
Briefs: Physical Sciences
Electrokinetic In Situ Treatment of Metal-Contaminated Soil
An electrokinetic technique has been developed as a means of in situ remediation of soils, sludges, and sediments that are contaminated with heavy metals. Examples of common metal contaminants that can be removed by this technique include cadmium, chromium, zinc, lead, mercury, and...
Briefs: Physical Sciences
Sonar-beam-steering devices of the proposed type would contain no moving parts and would be considerably smaller and less power-hungry, relative to conventional multiple-beam sonar arrays. The...
Feature Image
Briefs: Physical Sciences
The term "champagne heat pump" denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United...
Feature Image
Briefs: Physical Sciences
Two condensers designed for use in dissipating heat carried by working fluids feature two-phase, self-adjusting configurations such that their working lengths automatically vary to suit their input power levels and/or...
Feature Image
Briefs: Physical Sciences
Sensor for Monitoring Nanodevice-Fabrication Plasmas
The term "plasma process diagnostics" (PPD) refers to a spectroscopic technique and sensing hardware that have been proposed for monitoring plasma processes used to fabricate electronic devices that feature sizes as small as several nanometers. Nanometer dimensions are characteristic of the...
Briefs: Physical Sciences
Slotting Fins of Heat Exchangers To Provide Thermal Breaks
Heat exchangers that include slotted fins (in contradistinction to continuous fins) have been invented. The slotting of the fins provides thermal breaks that reduce thermal conduction along flow paths (longitudinal thermal conduction), which reduces heat-transfer efficiency. By increasing...
Briefs: Physical Sciences
Methane Clathrate Hydrate Prospecting
A method of prospecting for methane has been devised. The impetus for this method lies in the abundance of CH4 and the growing shortages of other fuels. The method is intended especially to enable identification of subpermafrost locations where significant amounts of methane are trapped in the form of methane...
Briefs: Physical Sciences
Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution...
Feature Image
Briefs: Physical Sciences
A method of processing digital image data to detect edges includes the use of fuzzy reasoning. The method is completely adaptive and does not require any advance knowledge of an image.
Feature Image
Briefs: Physical Sciences
Foam Sensor Structures Would Be Self-Deployable and Survive Hard Landings
A document proposes systems of sensors encased in cold hibernated elastic memory (CHEM) structures for exploring remote planets. The CHEM concept was described in two prior NASA Tech Briefs articles, including “Cold Hibernated Elastic Memory (CHEM) Expandable Structures”...
Briefs: Physical Sciences
Real-Gas Effects on Binary Mixing Layers
This paper presents a computational study of real-gas effects on the mean flow and temporal stability of heptane/ nitrogen and oxygen/ hydrogen mixing layers at supercritical pressures. These layers consist of two counter- flowing free streams of different composition, temperature, and density. As in related...
Briefs: Physical Sciences
Wedge Heat-Flux Indicators for Flash Thermography
Wedge indicators have been proposed for measuring thermal radiation that impinges on specimens illuminated by flash lamps for thermographic inspection. Heat fluxes measured by use of these indicators would be used, along with known thermal, radiative, and geometric properties of the specimens, to...
Briefs: Physical Sciences
Earth-Space Link Attenuation Estimation via Ground Radar Kdp
A method of predicting attenuation on microwave Earth/ spacecraft comm- unication links, over wide areas and under various atmospheric conditions, has been developed. In the area around the ground station locations, a nearly horizontally aimed polarimetric S-band ground radar measures the...
Briefs: Physical Sciences
Update on Area Production in Mixing of Supercritical Fluids
The paper “Turbulence and Area Production in Binary-Species, Super- critical Transitional Mixing Layers” presents a more recent account of the research sum- marized at an earlier stage in “Area Production in Super- critical, Transitional Mixing Layers” (NPO-30425), NASA Tech...
Briefs: Physical Sciences
Dyakonov-Perel Effect on Spin Dephasing in n-Type GaAs
A paper presents a study of the contribution of the Dyakonov-Perel (DP) effect to spin dephasing in electron-donor-doped bulk GaAs in the presence of an applied steady, moderate magnetic field perpendicular to the growth axis of the GaAs crystal. (The DP effect is an electron-wave-...
Briefs: Physical Sciences
Conventional commercial spectrometers or spectrophotometers are usually able to measure optical spectrum from a specified surface area at one point....
Feature Image
Briefs: Physical Sciences
Reconditioned Test Equipment as a Key Driver in Reducing Life Cycle Support Costs
Previously owned test and measurement equipment has been purchased for over 50 years by the United States military, agencies of the Federal gov- ernment, and prime contractors that support these organizations. Yet, despite the significant amount of previously owned...

Videos