Briefs : Materials
Susceptor-Coating Materials for Growth of 4H-SiC

Several materials have shown promise for coating graphite susceptors used in epitaxial growth of 4H-SiC. The development of appropriate susceptor-coating materials is an essential part of continuing efforts to produce high-quality, thick, undoped and lightly doped epilayers of 4H-SiC for use as...

Briefs : Materials
Priming Ceramic Materials for Better Waterproofing

An improved process for waterproofing ceramic materials — especially lightweight ceramic insulation materials in both rigid (tile) and flexible (blanket) form — has been invented. In this process, traditional waterproofing agents are used, but before the waterproofing agents are applied, the...

Briefs : Mechanical & Fluid Systems
Failure-Resistant Multiline Tethers

Hoytethers™ are failure-resistant multiline tethers named after their inventor, Robert Hoyt. They were originally intended for use in outer space to provide reliable tethering of satellites in the presence of orbital-debris and micrometeorite impacts that can sever single-line tethers. Hoytethers™ may also...

Briefs : Mechanical & Fluid Systems
Program Simulates Flights of Advanced Aerospace Vehicles

Marshall Aerospace Vehicle Representation in C (MAVERIC) is a C-language computer program developed for use in performing high-fidelity simulations of flights and analyses of the guidance and control performances of the X-33 aerospace vehicle and the VentureStar reusable launch vehicle...

Briefs : Medical
Determining Glucose Levels From NIR Raman Spectra of Eyes

A developmental noninvasive method of determining the concentration of glucose in blood is based on (1) the acquisition of a near-infrared (NIR) Raman spectrum from the aqueous humor of an eye, (2) analyzing the spectrum by a combination of techniques described below, and (3) recognition...

Briefs : Test & Measurement
Improved Electrical-Impedance Body-Fluids Monitor

The Johnson Space Center (JSC) body-fluids monitor advances the state of the art of measuring hydration levels in humans during spaceflight. Neither bulky nor heavy, this noninvasive instrument is built around a commercial inductance-capacitance-resistance meter, which is used to obtain...

Briefs : Test & Measurement
Software for Testing Access List Integrity

Many networks rely on firewalls or filtering routers for frontline network security. Packet filtering firewalls or routers filter incoming or outgoing packets based on a set of access rules. The IP (Internet Protocol) Packet Generator computer program assists in verifying that a packet filtering...

Briefs : Information Technology
Program for Parallel Distributed Processing

A software system has been devised to manage automatically (1) the distribution of mutually independent computing tasks to computer workstations in NASA's Flight Design and Analysis System (FADS) network and (2) the execution of those tasks on those workstations. This program parallelizes serial tasks,...

Briefs : Mechanical & Fluid Systems
Spacecraft Solar-Wind Trim Panels for Pointing

A report proposes that spacecraft assigned to orbits distant from the Earth be equipped with trim panels that would intercept the solar wind to generate small torques to correct for disturbance torques and thereby help to maintain the spacecraft pointed in the required directions. Paired panels...

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
Subpixel Map Registration and Estimation of Uncertainty

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 equipped with stereoscopic vision equipment for mapping the local terrain and with sensors for determining...

Briefs : Mechanical & Fluid Systems
Control Methodology To Alter Automobile Rollover Tendencies

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 similar maneuvers. At the time of reporting the information for this article, hardware and software to implement...

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 : Information Technology
A Method for Designing Low-Pass FIR Digital Filters

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 series of data samples. The method is implemented by use of design equations that contain parameters that...

Briefs : Materials
Computer Code Generates Two-Dimensional Unstructured Grids

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 shapes. The bounding shapes can be singly or multiply connected two-dimensional regions. The figure depicts...

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