Tech Briefs

Using Laser-Induced Incandescence To Measure Soot in Exhaust

This system incorporates several improvements over prior LII soot-measuring systems. An instrumentation system exploits laser-induced incandescence (LII) to measure the concentration of soot particles in an exhaust stream from an engine, furnace, or industrial process that burns hydrocarbon fuel. In comparison with LII soot-concentration-measuring systems that have been described in prior NASA Tech Briefs articles, this system is more complex and more capable.

Posted in: Briefs, Physical Sciences

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Software Enables Advanced Modeling of Backlights for Flat Panel Displays

This enhanced illumination design and analysis program, called LightTools® 5.1, enables easy and accurate modeling of sophisticated backlights for flat panel displays. It can simulate the surface textures used for backlights, with built-in flexibility to vary the shape, size, and spacing of the texture elements.

Posted in: Briefs, Physical Sciences

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Thermal and Compressed-Air Storage System Provides Alternative to UPS Batteries

Three mature energy-storage technologies are combined in a new system to replace lead-acid batteries. Virtually all businesses and industries are vulnerable to electric power disturbances such as outages, sags, swells, and harmonics. These problems are less of an issue for data centers, protected behind their walls of Uninterruptible Power Supply (UPS) systems. But the typical battery-backed UPS is too fragile for use in less protected environments. UPS batteries must be maintained in a narrow temperature range and fail prematurely when subjected to a steady diet of step loads and motor drives. About six years ago, flywheel-based UPS products became commercially available. These devices store energy as rotational inertia, and are rugged enough to survive on the factory floor. However, flywheels have relatively short ride-through energy and are best-suited for use in locations with backup generators.

Posted in: Briefs, Mechanical Components

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Carbon-Fiber Brush Heat Exchangers

High thermal conductance between uneven surfaces could be achieved with low clamping force. Velvetlike and brushlike pads of carbon fibers have been proposed for use as mechanically compliant, highly thermally conductive interfaces for transferring heat. A pad of this type would be formed by attaching short carbon fibers to either or both of two objects that one desires to place in thermal contact with each other. The purpose of using a thermal-contact pad of this or any other type is to reduce the thermal resistance of an interface between a heat source (e.g., a module that contains electronic circuitry) and a heat sink (e.g., a common finned heat sink).

Posted in: Briefs, Mechanical Components

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Algorithm Determines Wind Speed and Direction FromVenturi-Sensor Data

Speed and direction are calculated from the spatial distribution of pressure readings. An algorithm computes the velocity of wind from the readings of an instrument like the one described in “Three-Dimensional Venturi Sensor for Measuring Extreme Winds” (KSC-12435), NASA Tech Briefs, Vol. 27, No. 9 (September 2003), page 32. To recapitulate: The sensor has no moving parts and is a compact, rugged means of measuring wind vectors having magnitudes of as much as 300 mph (134 m/s). The sensor includes a Venturi gap bounded by a curved upper and a curved lower surface that are axisymmetric with respect to a vertical axis and mirror-symmetric with respect to a horizontal midplane. One of the curved surfaces is instrumented with multiple ports for measuring dynamic pressures (see figure). The sensor also incorporates auxiliary sensors for measuring temperature, relative humidity, and static atmospheric pressure.

Posted in: Briefs, TSP, Information Sciences

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Feature-Identification and Data-Compression Software

A report discusses the continuing development of Windows Interface for Nominal Displacement Selection (WINDS), a computer program for automated analysis of images of the Sun and planets acquired by scientific instruments aboard spacecraft. WINDS is intended to afford capabilities for identification of features, measurement of displacements and velocities, analysis of terrain and of atmospheres, and synthesis of animation sequences of images of terrains and atmospheres from small sets of samples by use of velocity based interpolation. A major element of WINDS will be a nonlinear correlator capable of tracking small features in complex image sequences. For dynamic image sequences, the correlator will enable compression of data by factors >100. In processing image data, WINDS will take account of such factors as texture in image data, rotation of features during measurement intervals, effects of viewing and solar illumination angles, and vertical structures of atmospheres. WINDS will also take account of positions, aiming directions, and fields of view of cameras to determine three-dimensional feature structures by use of triangulation and stereoscopic analysis techniques.

Posted in: Briefs, TSP, Information Sciences

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Masked Proportional Routing

This procedure enables adaptation to changing network conditions. Masked proportional routing is an improved procedure for choosing links between adjacent nodes of a network for the purpose of transporting an entity from a source node (“A”) to a destination node (“B”). The entity could be, for example, a physical object to be shipped, in which case the nodes would represent waypoints and the links would represent roads or other paths between waypoints. For another example, the entity could be a message or packet of data to be transmitted from A to B, in which case the nodes could be computer-controlled switching stations and the links could be communication channels between the stations. In yet another example, an entity could represent a workpiece while links and nodes could represent, respectively, manufacturing processes and stages in the progress of the workpiece towards a finished product. More generally, the nodes could represent states of an entity and the links could represent allowed transitions of the entity.

Posted in: Briefs, TSP, Information Sciences

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