January 2001

Briefs : Electronics & Computers
Submillimeter-Wave Image Sensor

A proposed monolithic planar array of miniature dipole antennas, diodes, and associated input/output circuitry would serve as a prototype of image sensors for submillimeter-wavelength video cameras (see Figure 1). Sensors of this type could be designed to operate as either direct or heterodyne detectors of...

Briefs : Mechanical & Fluid Systems
Ultrasonic/Sonic Drill/Corers With Integrated Sensors

Easy-to-use, low-power-consumption apparatuses capable of drilling to acquire core samples of thick layers of material and/or measuring physical and chemical characteristics of the layers are undergoing development. A major component of an apparatus of this type is an ultrasonic/sonic...

Briefs : Mechanical & Fluid Systems
Normally Closed, Piezoelectrically Actuated Microvalve

A normally closed, piezoelectrically actuated microvalve is being developed as a prototype of valves in microfluidic systems and other microelectromechanical systems (MEMS) intended for operation in outer space. Terrestrial MEMS in which such valves could also prove useful include...

Briefs : Physical Sciences
Magnetostrictively Actuated Valves for Cryosurgical Probes

In cryosurgical probes of a type now undergoing development, the flow of coolant (typically, liquid nitrogen) would be regulated by magnetostrictively actuated needle valves controlled by use of superconductive electromagnet coils. In comparison with cryosurgical probes now in use, the...

Briefs : Physical Sciences
Remote Sensing of Electric Fields in Clouds

A proposed method for remote sensing of the electric field in a cloud that contains ice crystals would exploit the relationship between (1) the polarization-dependent radiometric or radar brightness of the cloud and (2) the average or bulk orientation of the crystals as affected by the electric field....

Briefs : Electronics & Computers
Wireless-Communication Headset Subsystem To Enhance Signaling

A special-purpose communications subsystem provides a push-to-talk signal to a communication system as if the individual was directly wired to the system. The subsystem also permits multiple wireless users to operate independently in the same environment. This interface operates in...

Briefs : Electronics & Computers
Power Amplifier With 9 to 13 dB of Gain From 65 to 146 GHz

A three-stage power amplifier has been developed, capable of operating without tuning, over a wide frequency band ranging well above 100 GHz. The original intended application of this circuit is as a driver amplifier for a passive frequency multiplier that would generate a...

Briefs : Electronics & Computers
Humidity Interlock for Protecting a Cooled Laser Crystal

A humidity interlock has been developed to prevent damage that could be caused by condensation of water on a delicate and expensive laser crystal that must be maintained at a temperature below ambient during operation. The humidity interlock is installed in conjunction with the laser...

Briefs : Test & Measurement
A Lightweight Ambulatory Physiological Monitoring System

The Autogenic-Feedback System-2 (AFS-2) is a biomedical instrumentation package that was designed and built at Ames Research Center for use during the September 1992 Spacelab-J (STS-47) mission. The AFS-2 performed successfully during that mission and was rated by members of NASA's...

Briefs : Test & Measurement
Improvements in a Lightning-Measuring Instrument

Some improvements have been made in the instrument described in "Instrument Records Magnetic Fields Generated by Lightning" (KSC-11769) NASA Tech Briefs, Vol. 19, No. 4 (April 1995), page 38. To conserve battery energy, the instrument was made to record the output of only one of three mutually...

Briefs : Test & Measurement
Web-Based Technology Distributes Lean Models

Everybody creates models. These models are used to understand how products will hold up to the stresses, use, and abuse of real-world deployment; analyze the impact of design decisions on cost; simulate interactions; or evaluate numerous other metrics. Unfortunately, because of the variety of software...

Briefs : Test & Measurement
Broad-Band, Noninvasive Radio-Frequency Current Probe

An instrument that noninvasively measures alternating current over a broad frequency band (typically from about 0.3 to about 110 MHz) has been invented. This instrument could be especially useful for assessing radio-frequency hazards by measuring currents in various parts of humans or...

Briefs : Software
Software Guides Aeroelastic-Systems Design

Accurately and efficiently predicting the unsteady dynamics of coupled, fluid-structure systems significantly reduces the cost of designing, testing, and maintaining fixed-wing aircraft, rotorcraft, and turbomachinery. It also improves safety. Organizations can realize substantial savings by...

Briefs : Software
Postprocessing Software for Micromechanics Analysis Code

The Micromechanics Analysis Code Post-Processing (MACPOST) computer program is designed primarily to serve as an improved means of processing the output of the Micromechanics Analysis Code With Generalized Method of Cells (MAC/GMC) computer program. [MAC/GMC was described in "Comprehensive...

Briefs : Materials
Better Packaging for Miniature Immersible Diagnostic Systems

A method of packaging now under development would afford improved protection and functionality for miniature immersible diagnostic systems (MIDS). The method involves covering a MIDS with a thin hermetic film that, if necessary, can be broken on command to expose one or more sensor(s)...

Briefs : Materials
Lightweight Composite-Material Tanks for Cryogenic Liquids

A lightweight composite-material tank suitable for the storage and transport of liquid oxygen and other cryogenic liquids has been developed. The tank includes a metallic liner compatible with liquid oxygen, a graphite/ epoxy overwrap, an insulating layer of lightweight polyurethane...

Briefs : Materials
Improved Formulation and Deposition of Ablative Insulation

The term "Marshall Convergent Coating-1" ("MCC-1") denotes an improved formulation and a concomitantly improved method of spray deposition of a cork-and-glass-filled epoxy ablative thermal-insulation material. MCC-1 has been used on the space shuttle solid rocket booster and on some Air...

Briefs : Mechanical & Fluid Systems
Flow-Concentrating Supersonic Gas/Liquid Nozzles

Flow-concentrating supersonic gas/liquid nozzles have been invented for use in cleaning and in verifying the cleanliness of tanks, pipes, tubes, machine parts, and structures. The overall function of these nozzles is to generate concentrated two-phase flows, the mechanical action of which is...

Briefs : Mechanical & Fluid Systems
Advanced Rigid/Inflatable Spacecraft Habitation Module

A large, lightweight, economical, easy-to-manufacture human-habitation module that is well suited to long-term use in outer space has been developed. Modules like this one have potential for commercial applications, including the provision of human habitats for the commercialization of outer...

Briefs : Mechanical & Fluid Systems
Parabolic Membrane-Thickness Variation for Inflatable Mirror

According to a proposal, membranes to be used in inflatable focusing mirrors (see Figure 1) would be designed and fabricated with parabolic radial variations of thickness. More specifically, for a mirror membrane with a diameter D, the thickness (t) at a given radial distance (r) from...

Briefs : Medical
Slide-Staining System for Microgravity or Gravity

The centrifuge-operated slide stainer (COSS) is a conceptual self-contained system that could be attractive for use in a variety of histological and cytological procedures in both microgravity and normal Earth gravity. The COSS was conceived specifically for use in staining blood smears on glass...

Briefs : Photonics/Optics
Traveling-Wave Photomixer With Angle-Tuned Phase Matching

An experimental traveling-wave photomixing device generates narrow-band electromagnetic radiation at frequencies up to a few terahertz. The device is, potentially, a prototype of terahertz local oscillators for heterodyne instrumentation for submillimeter-wavelength spectrometry and...

Briefs : Photonics/Optics
Holographic Circle-to-Point Converter

The figure schematically depicts the use of a special-purpose holographic plate to focus light from (1) circular interference fringes generated by a Fabry-Perot etalon to (2) a series of points, each illuminated in a different wavelength interval. This holographic circle-to-point converter was invented to...

Briefs : Photonics/Optics
Compact, Low-Power, Low-Voltage Laser Ignition System

A prototype laser ignition system has been developed for use in a hydrogen/oxygen-burning spacecraft thruster. The system could readily be adapted to terrestrial applications in which spark, catalytic, or pyrotechnic igniters are now used.

Briefs : Photonics/Optics
Mirror Structures Made of Pyrolytic Graphite

Experiments have demonstrated the feasibility of making mirror structures that comprise a thin face plate of chemical-vapor-deposited (CVD) pyrolytic graphite (PG) integrated with a thicker backing plate of CVD PG open-cell foam. The backing plate serves as a stiff structural support for the face...

Briefs : Photonics/Optics
Using Laser Rangefinders To Align Two Structures

An optoelectronic system provides information on the relative position and orientation of two structures that are required to be brought together slowly and gently in a prescribed alignment. In the original intended application, the two structures will be the X-33 launch vehicle and a launch...

Briefs : Photonics/Optics
Designing for Optimum Response in a Pushbroom Spectrometer

A method of designing a compact pushbroom imaging spectrometer includes explicit consideration and minimization of nonuniformity of spatial and spectral response. It appears that prior to the development of this method, the issue of nonuniformity of response was addressed haphazardly....

Briefs : Photonics/Optics
Laser-Induced Rotation of a Levitated Sample in a Vacuum

A high-power laser beam can be used to apply a torque to a sample of material that is electromagnetically and/or electrostatically levitated in a vacuum. The torque can be used to alter the state of rotation of the sample; this is an important capability because control of the state of...

Briefs : Photonics/Optics
Tailoring Cores of Optical Fibers by a Sol-Gel Method

A method of tailoring the cores of optical fibers to obtain optical properties needed for specific photonic applications exploits the sol-gel process. The method is expected to open new avenues of development of fiber-optic sensors for measuring strain, temperature, intensity of ionizing...

Briefs : Photonics/Optics
Optical Surfaces Based on Arrays of Microscopic Pillars

Surfaces would be textured with dense arrays of pillars characterized by micron and submicron dimensions, according to a proposal, in order to impart desired optical properties to the surfaces. In an important class of potential applications, suitably shaped and dimensioned microscopic...

Briefs : Photonics/Optics
Nonvolatile Holographic Storage in Doubly Doped LiNbO₃

Recent research has demonstrated the feasibility of an all-optical method of recording and readout of holograms in photorefractive crystals, with capabilities for both nonvolatile storage and erasure on demand. Heretofore, volatility has been the primary remaining obstacle to the full...

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