Briefs: Medical

Electrokinetically enhanced bioremediation (EEB) is a method of engineered bioremediation of soil contaminated by such organic compounds as solvents and petroleum products. As depicted...

Briefs: Medical
Microgravity Tissue Engineering

A continuing program of research and development focuses on engineering of functional cartilage and cardiac muscle for scientific research and for eventual use in transplants. The program involves the use of cells, polymer scaffolds, and bioreactor vessels. A polymer scaffold serves as a three-dimensional...

Briefs: Photonics/Optics

An apparatus that includes a pulsed electron gun and a high-resolution ultraviolet spectrometer has been developed for use in (1) pulsed electron-impact excitation of transitions...

Briefs: Photonics/Optics

Infrared-sensor systems for real-time detection of accretion of ice on helicopter rotor blades are undergoing development. By providing early warnings of icing conditions, these...

Briefs: Photonics/Optics

Efforts are under way to develop back-surface-illuminated, thinned silicon charge-coupled devices (CCDs) with delta doping and integral optical filters to be used as image...

Briefs: Photonics/Optics
Capture and Escape of Charge Carriers in Quantum Dots

A report describes an experimental investigation of effects of thermally induced intermixing of In0.6Ga0.4As and GaAs on the dynamics of photoexcited charge carriers in In0.6Ga0.4As/GaAs quantum dots. The quantum dots (nanometer-size islands of...

Briefs: Photonics/Optics
Rayleigh-Scattering Measurements in Underexpanded Jets

A report describes experiments in which time-averaged and unsteady local variations in the densities of underexpanded supersonic free jets issuing from a choked circular nozzle were measured by laser-induced Rayleigh scattering. This study is part of a continuing effort to understand the...

Briefs: Photonics/Optics

Common-path heterodyne interferometers (COPHIs) have been proposed for measuring small variations in the heights of surfaces. A COPHI could be used, for example, to measure the deviation of the surface...

Briefs: Physical Sciences

Shared-aperture multiplexed holographic scanning telescopes have been proposed for use in lidar transceivers and other laser transmitters and receivers in remote sensing...

Briefs: Photonics/Optics

Two polarization-recycling techniques have been proposed to increase the efficiency of illumination of liquid-crystal display (LCD) panels. The motivation for this proposal lies in...

Briefs: Materials

Filled skutterudites have shown promise as semiconducting materials with superior thermoelectric properties at temperatures up to at least 650 °C. This finding is a breakthrough in a...

Briefs: Physical Sciences

The term "optical nose" refers to a fiber-optic chemical sensor of a type that has been proposed to enable distributed measurement of the concentrations of...

Briefs: Mechanical & Fluid Systems

A compact, low-power device measures pressure via the pressure-induced damping of oscillation of a small mechanical resonator. To achieve compactness and low mass — and thus...

Briefs: Electronics & Computers

A low-power capacitive proximity sensor has been developed as a prototype of wheel-contact sensors for a small robotic vehicle. The sensor is integrated into a wheel and consists of only a few...

Briefs: Physical Sciences

A recently developed type of fiber-optic temperature sensor utilizes narrow-band near-infrared radiation emitted by rare-earth ions. These sensors are suitable for use in harsh environments at...

Briefs: Physical Sciences
Capacitive Sensor for Measuring Level of Liquid Nitrogen

The feasibility of a capacitive sensor for measuring the level of liquid nitrogen in a container has been demonstrated. The basic sensor design could also readily be adapted to measurement of the levels of cryogenic liquids other than nitrogen.

Briefs: Electronics & Computers
Black Jack GPS Receiver

The Black Jack (BJ) receiver is the revolutionary flight Global Positioning System (GPS) receiver developed by NASA to fill future needs for orbit-based GPS science. These range from a receiver to determine precise (1-cm radial accuracy goal for JASON-1) orbits, to missions using the GPS signals for remote sensing of the...

Briefs: Physical Sciences

Microelectromechanical sensors based on magnetoresistance have been proposed. Like other microelectromechanical sensors, these would be used to measure physical quantities that can be...

Briefs: Electronics & Computers

Digitally programmable analog membership-function circuits have been invented for use in fuzzy-logic systems. Heretofore, fuzzy membership functions have been implemented, variously,...

Briefs: Electronics & Computers
Regenerative Pseudonoise Ranging

In a proposed improved technique for pseudonoise turnaround ranging of a radio transponder, the pseudonoise modulating signal would be regenerated in the transponder. The net result of the regeneration would be an increase in the effective return ranging power. This increase would provide some margin for...

Briefs: Electronics & Computers

Analog electronic circuits that operate with pulsed input and output signals are undergoing development. The pulsing behavior of these circuits is modeled after a similar behavior, called...

Briefs: Electronics & Computers
Weighing Scales Based on Low-Power Strain-Gauge Circuits

Weighing scales (e.g., kitchen and bathroom scales) of a proposed type would incorporate sensory devices like the one described in "Low-Power, Microprocessor-Controlled Strain-Gauge Circuit" (NPO-19750), NASA Tech Briefs, Vol. 21, No. 1 (January 1997), page 45. Unlike other weighing scales...

Briefs: Software
Generating Maps of the Ionosphere From GPS Measurements

The Global Ionospheric Monitoring and Forecasting System (GIMSYS) computer program generates global maps of the total electron content (TEC) (electron density integrated over all altitude) of the ionosphere, maps of ionospheric irregularities, and related data byproducts. The maps are...

Briefs: Software
Program for Simulating Rotor Dynamics on Personal Computers

ARDS (Analysis of RotorDynamic Systems) is a public-domain computer program that simulates transient and steady-state dynamics of a rotary machine that can include as many as five interconnected flexible shafts. ARDS can be used to analyze the dynamics of such diverse machines as...

Briefs: Software
Software for Monitoring and Controlling DSN Operations

Network Monitor and Control (NMC) Automation Assembly (AA) is a component of the NMC software system, which is used for controlling an antenna connection in the Deep Space Network. NMC AA could also be adapted to commercial applications (e.g., chemical processing), in which human operators...

Briefs: Materials

Alkoxides of lithium have been found to be useful as electrolyte additives to improve the low-temperature performance of rechargeable lithium-ion electrochemical cells. As...

Briefs: Materials

Aliphatic esters have been found to be useful as electrolyte additives for improving the low-temperature performances of rechargeable lithium-ion electrochemical cells. The...

Briefs: Materials

Ethyl methyl carbonate (EMC) has been found to be a suitable cosolvent, along with three other carbonate solvents, for incorporation into electrolytes to enhance the low-temperature...

Briefs: Materials

Titanium disulfide has been found to be attractive as an alternative to graphite as the anode material in rechargeable lithium-ion electrochemical cells that are required to operate at...

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