Special Coverage

Supercomputer Cooling System Uses Refrigerant to Replace Water
Computer Chips Calculate and Store in an Integrated Unit
Electron-to-Photon Communication for Quantum Computing
Mechanoresponsive Healing Polymers
Variable Permeability Magnetometer Systems and Methods for Aerospace Applications
Evaluation Standard for Robotic Research
Small Robot Has Outstanding Vertical Agility
Smart Optical Material Characterization System and Method
Lightweight, Flexible Thermal Protection System for Fire Protection

Bidirectional Pressure-Regulator System

This system can be used in regenerative fuel cell systems. A bidirectional pressure-regulator system has been devised for use in a regenerative fuel cell system. The bidirectional pressure- regulator acts as a back-pressure regulator as gas flows through the bidirectional pressure-regulator in one direction. Later, the flow of gas goes through the regulator in the opposite direction and the bidirectional pressure-regulator operates as a pressure- reducing pressure regulator. In the regenerative fuel cell system, there are two such bidirectional regulators, one for the hydrogen gas and another for the oxygen gas. The flow of gases goes from the regenerative fuel cell system to the gas storage tanks when energy is being stored, and reverses direction, flowing from the storage tanks to the regenerative fuel cell system when the stored energy is being withdrawn from the regenerative fuel cell system. Having a single bidirectional regulator replaces two unidirectional regulators, plumbing, and multiple valves needed to reverse the flow direction. The term “bidirectional” refers to both the bidirectional nature of the gas flows and capability of each pressure regulator to control the pressure on either its upstream or downstream side, regardless of the direction of flow.

Posted in: Briefs, TSP, Physical Sciences, Computer software and hardware, Sensors and actuators, Fuel cells, Gases


Neon as a Buffer Gas for a Mercury-Ion Clock

One aspect of the topic of “Compact, Highly Stable Ion Clock” (NPO-43075), NASA Tech Briefs, Vol. 32, No. 5 (May 2008), page 63, is examined in more detail. To recapitulate: A developmental miniature mercury-ion clock has stability comparable to that of a hydrogen-maser clock. The ion-handling components are housed in a sealed vacuum tube, wherein a getter pump is used to maintain the partial vacuum, and the evacuated tube is backfilled with mercury vapor in a buffer gas.

Posted in: Briefs, Physical Sciences, Research and development, Gases


Lossless, Multi-Spectral Data Compressor for Improved Compression for Pushbroom-Type Instruments

A modified data compression algorithm could be used on commercial satellites or other applications with multispectral imaging instruments. A low-complexity lossless algorithm for compression of multispectral data has been developed that takes into account pushbroom-type multispectral imagers’ properties in order to make the file compression more effective. These types of imagers use a detector array to acquire data in spatial-spectral slices. Each detector element corresponds to a specific spectral band and cross-track position. Because the characteristics of detector elements generally vary somewhat from element to element, cross-track adjacent samples in a given spectral band are not as similar as they are in an instrument that uses the same detector for all samples in a given spectral band (e.g. in a whiskbroom-type instrument). Along-track adjacent samples will tend to be very similar.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Data acquisition and handling, Imaging and visualization


NbxTi1–xN Superconducting-Nanowire Single-Photon Detectors

Potential applications include optical communications and quantum cryptography. Superconducting- nanowire single-photon detectors (SNSPDs) in which NbxTi1–xN (where x

Posted in: Briefs, Physical Sciences, Optics, Conductivity, Nanomaterials


Miniature Incandescent Lamps as Fiber-Optic Light Sources

These lamps can be used without coupling optics. Miniature incandescent lamps of a special type have been invented to satisfy a need for compact, rapid- response, rugged, broadband, power- efficient, fiber-optic- coupled light sources for diverse purposes that could include calibrating spectrometers, interrogating optical sensors, spot illumination, and spot heating. A lamp of this type (see figure) includes a re-entrant planar spiral filament mounted within a ceramic package heretofore normally used to house an integrated-circuit chip. The package is closed with a window heretofore normally used in ultraviolet illumination to erase volatile electronic memories. The size and shape of the filament and the proximity of the filament to the window are such that light emitted by the filament can be coupled efficiently to an optical fiber without intervening optics.

Posted in: Briefs, TSP, Physical Sciences, Exterior lighting, Downsizing, Fiber optics, Interior lighting


Prism Window for Optical Alignment

Prism windows could be generally useful in manufacture of optical instruments. A prism window has been devised for use, with an autocollimator, in aligning optical components that are (1) required to be oriented parallel to each other and/or at a specified angle of incidence with respect to a common optical path and (2) mounted at different positions along the common optical path. The prism window can also be used to align a single optical component at a specified angle of incidence. Prism windows could be generally useful for orienting optical components in manufacture of optical instruments.

Posted in: Briefs, TSP, Physical Sciences, Optics


Range-Gated Metrology With Compact Optical Head

A compact, single-fiber optical head requires minimal internal alignment. This work represents a radical simplification in the design of the optical head needed for high-precision laser ranging applications. The optical head is now a single fiber-optic collimator with dimensions of order of 1×1×2 cm, which can be easily integrated into the system being measured with minimal footprint. Previous heads were significantly larger, with multiple optical elements requiring careful alignment. The new design has only one optical fiber per head, rather than four, making it much easier to multiplex between tens or hundreds of heads. It is capable of subnanometer precision, consistent with the demanding requirements of new missions.

Posted in: Briefs, TSP, Physical Sciences, Measurements, Fiber optics, Lasers, Nanotechnology


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