Briefs: Materials
Reaction-Forming Method for Joining SiC-Based Parts

Two reports present additional details about the method described in "Reaction-Forming Method for Joining SiC-Based Ceramic Parts" (LEW-16661), NASA Tech Briefs, Vol. 23, No. 3 (March 1999), page 50. To recapitulate: A carbonaceous mixture (typically a paste) is applied to a joint between...

Briefs: Information Technology

A method of determining the location and the uncertainty in the location of a mobile robot to subpixel resolution on a map grid has been devised. The method is applicable to a robot...

Briefs: Mechanical & Fluid Systems

A methodology of active control has been developed in an effort to alter (preferably to reduce) the tendency of a four-wheel land vehicle to roll over during tight turns and...

Briefs: Mechanical & Fluid Systems
Program for Computing Dynamics of Multiple Bodies

Symbolic Generator-Based Efficient Multibody Dynamics Algorithm (SOMBAT) is a program that enables speedy and accurate computations that solve equations of motion of multiple bodies. Originally intended for space-based applications (i.e., solving equations for the dynamics of a cluster of...

Briefs: Electronics & Computers

A NASA Small Business Innovation Research (SBIR) project has led to the development of high-rate (155.52-Mb/s) modems for use in high-quality wireless data communications. The research was...

Briefs: Motion Control

The gaseous hydrogen flow control vale (GH2FCV; see Figure 1) is a critical space shuttle component that controls the pressure of the hydrogen external tank during launch and ascent...

Briefs: Electronics & Computers

A microwave phase shifter that can be tuned by varying both electric and magnetic fields has been developed. This device combines all the advantages of prior electrically and magnetically tunable...

Briefs: Electronics & Computers

Recent advances in laser cooling and trapping of neutral atoms in magneto-optic traps (MOTs) would be exploited in ion-trap-based atomic clocks, according to a proposal. Beams of...

Briefs: Information Technology

A class of finite-impulse-response (FIR) digital filters has been developed to perform certain frequency-limiting, decimation, and differentiation (with respect to time) functions on a time...

Briefs: Materials

TRiangular Unstructured Mesh generator by Point insEr Tion (TRUMPET) is a computer program that generates meshes that are composed of triangular cells and are bounded by complex...

Briefs: Materials

A method of analyzing and designing laminated composite-material wraps for columns, arches, domes, and other large reinforced-concrete structures involves an extension of...

Briefs: Materials
Software for Predicting Life of Metal-Matrix Composites

LIPS (LIFE PREDICTION SOFTWARE) is a computer program for predicting the life of an object that is made of a unidirectional-fiber/metal-matrix composite (MMC) material and that is subjected to mechanical loading along the fiber direction. The program is derived from a theory formulated to...

Briefs: Electronics & Computers

The figure schematically illustrates an optoelectronic security system in which binary information on the identity of a person or object is encoded in Bragg gratings in an optical...

Briefs: Electronics & Computers

The apparatus shown schematically in the figure is an optoelectronic shaft-angle encoder that measures absolute angles with high resolution. This encoder is an improved version of the...

Briefs: Electronics & Computers
High-Power Laser Illuminator

A laser illuminator system has been developed for use in automated tracking of objects. In its original application, the system illuminates a 5° conical region expected to contain a small satellite at a distance up to 750 m from the space shuttle. If the satellite comes within this region, then a receiving...

Briefs: Electronics & Computers

A communication controller circuit for a wind-tunnel model is undergoing development. The circuit is intended to serve as part of a highly miniaturized, distributed, modular electronic...

Briefs: Software

GENOA-PFA is a commercial version of the Composite Durability Structural Analysis (CODSTRAN) computer program, which simulates the progression of damage ultimately leading to...

Briefs: Materials
Molecular-Sieve Type 3Å

The term "Molecular-Sieve Type 3Å" denotes a clay-based, zeolite material that revolutionizes a fluid-purification process by removing trace water and iron from nitrogen tetroxide/nitric oxide (MON-3) mixtures used as oxidizer components of spacecraft propellants. Older processes of this type removed only water or iron...

Briefs: Electronics & Computers
Composite Graphite Anodes Containing Cyclic Ether Additives

Scientists have developed a type of composite graphite anode that will benefit the U.S. space program and private industry by increasing the rechargeability of lithium-ion batteries. Rechargeable lithium-ion batteries, which are used on the space shuttle and Space Station, are also used...

Briefs: Materials
Polypyrrole and Polyaniline Doped With Lignosulfonic Acid

Experiments have shown that electrically conductive polymers with water-soluble fractions can be synthesized by polymerization of pyrrole or aniline in the presence of lignosulfonic acid, which is a polymeric acid that can be derived relatively easily from the spent sulfite liquor...

Briefs: Mechanical & Fluid Systems

A leak-free valve has been proposed as a more reliable, less expensive, adaptable alternative to a one-time-opening, pyrotechnically actuated valve (pyrovalve). In the original intended application, the pyrovalve...

Briefs: Mechanical & Fluid Systems

Pneumatic cushions have been proposed for protecting the afterbodies of two-body instrumented soil-penetrator projectiles. These cushions would be, essentially, doughnut-shaped...

Briefs: Mechanical & Fluid Systems

Work performed at Johnson Space Center has brought about a major improvement in the means for measuring the bending that occurs whenever stress is applied to a bolted joint. This major improvement...

Briefs: Manufacturing & Prototyping
Improvements in Rapid Prototyping

Several improvements have been proposed for the fabrication process known as "rapid prototyping." In this process, a model or prototype of a solid object is built up by controlled ejection of molten polymeric material through programmed orifices to form patterned layers. The second layer is deposited on top of...

Briefs: Physical Sciences

An electron-beam ionizer has been designed to deliver ions to the entrance apertures of nine miniature quadrupole mass spectrometers in an array. A similar electron-beam ionizer could also...

Briefs: Physical Sciences

A computer-controlled instrumentation system has been developed for use in measuring concentrations of various atomic species in the exhaust gases of a space-shuttle main engine on a...

Briefs: Physical Sciences

The figure presents additional information on the optics of the atomic-absorption-spectroscopy (AAS) system described in the preceding article. The optics include (1) a periscopic...

Briefs: Physical Sciences

A technique for ultrasonic characterization of plates has been extended to tubes and curved structures in general. In this technique, as explained in more detail below, one performs...

Briefs: Physical Sciences
Detecting Metal Ions by Voltammetry Using Diamond Electrodes

Experiments have demonstrated the feasibility of detecting multiple species of toxic metal ions and other ions of interest dissolved in water, by means of voltammetry with electrically conductive artificial diamond electrodes. Diamond is attractive as an electrode material because it...

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