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Briefs: Physical Sciences
The concept of a transparent conveyor of small loose dielectric particles or small amounts of dielectric liquids has emerged as an outgrowth of an effort to develop efficient, reliable...
Briefs: Physical Sciences
The multi-cone model is a computational model for estimating ionospheric delays of Global Positioning System (GPS) signals. It is a direct descendant of the conical-domain model, which was...
Briefs: Physical Sciences
Progress Toward a Compact, Highly Stable Ion Clock
There was an update on the subject of two previous NASA Tech Briefs articles: “Compact, Highly Stable Ion Clock” (NPO-43075), Vol. 32, No. 5 (May 2008), page 63; and “Neon as a Buffer Gas for a Mercury-Ion Clock” (NPO-42919), Vol. 32, No. 7 (July 2008), page 62. To recapitulate: A...
Briefs: Physical Sciences
Systematic studies have been performed on the sensitivity of GaN HEMT (high electron mobility transistor) sensors using various gate electrode designs and operational parameters. The results here show...
Briefs: Physical Sciences
On the Divergence of the Velocity Vector in Real-Gas Flow
A theoretical study was performed addressing the degree of applicability or inapplicability, to a real gas, of the occasionally stated belief that for an ideal gas, incompressibility is synonymous with a zero or very low Mach number. The measure of compressibility used in this study is the...
Briefs: Information Technology
Integrated Risk and Knowledge Management Program — IRKM-P
The NASA Exploration Systems Mission Directorate (ESMD) IRKM-P tightly couples risk management and knowledge management processes and tools to produce an effective “modern” work environment. IRKM-P objectives include: (1) to learn lessons from past and current programs (Apollo, Space...
Briefs: Information Technology
A method of constructing certain low-density parity-check (LDPC) codes by use of relatively simple loop-free coding modules has been developed. The subclasses of LDPC codes to which the...
Briefs: Information Technology
Low-density parity-check (LDPC) codes characterized by minimum Hamming distances proportional to block sizes have been demonstrated. Like the codes mentioned in the immediately...
Briefs: Electronics & Computers
MMICs With Radial Probe Transitions to Waveguides
A document presents an update on the innovation reported in “Integrated Radial Probe Transition From MMIC to Waveguide” (NPO-43957), NASA Tech Briefs Vol. 31, No. 5 (May 2007), page 38. To recapitulate: To enable operation or testing of a monolithic microwave integrated circuit (MMIC), it is...
Briefs: Electronics & Computers
Tests of Low-Noise MMIC Amplifier Module at 290 to 340 GHz
A document presents data from tests of a low-noise amplifier module operating in the frequency range from 290 to 340 GHz — said to be the highest-frequency low-noise, solid-state amplifier ever developed. The module comprised a three-stage monolithic microwave integrated circuit (MMIC)...
Briefs: Information Technology
Extending Newtonian Dynamics to Include Stochastic Processes
A paper presents further results of continuing research reported in several previous NASA Tech Briefs articles, the two most recent being “Stochastic Representations of Chaos Using Terminal Attractors” (NPO-41519), [Vol. 30, No. 5 (May 2006), page 57] and “Physical Principle for...
Briefs: Photonics/Optics
The acronym “CHAMP” (signifying “camera, hand lens, and microscope”) denotes any of several proposed optoelectronic instruments that would be capable of color imaging at working distances that...
Briefs: Physical Sciences
Lightweight cylindrical reflectors of a proposed type would be made from reflective membranes stretched between pairs of identically curved and identically oriented end rails. In each such...
Briefs: Physical Sciences
An apparatus for mid-infrared reflectance imaging has been developed as means of inspecting for subsurface damage in thermal-barrier coatings (TBCs). The apparatus is designed, more...
Briefs: Physical Sciences
Improving the Visible and Infrared Contrast Ratio of Microshutter Arrays
Three device improvements have been developed that dramatically enhance the contrast ratio of microshutters. The goal of a microshutter is to allow as much light through as possible when the shutters are in the open configuration, and preventing any light from passing through...
Briefs: Physical Sciences
Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been...
Briefs: Manufacturing & Prototyping
A new cell designed to mimic the photosynthetic processes of plants to convert carbon dioxide into carbonaceous products and oxygen at high efficiency, has an...
Briefs: Materials
Silicon Wafer-Scale Substrate for Microshutters and Detector Arrays
The silicon substrate carrier was created so that a large-area array (in this case 62,000+ elements of a microshutter array) and a variety of discrete passive and active devices could be mounted on a single board, similar to a printed circuit board. However, the density and...
Briefs: Mechanical & Fluid Systems
Thin-layered structures containing arrays of micromachined horns, denoted solid micro-horn arrays (SMIHAs), have been conceived as improved means of matching acoustic impedances between...
Briefs: Mechanical & Fluid Systems
An improved closed-loop controller has been built for a three-axis piezoelectric positioning stage. The stage can be any of a number of commercially available or custom-made units that...
Briefs: Physical Sciences
A method of dynamic self-locking has been demonstrated to be effective as a means of stabilizing the wavelength of light emitted by a vertical-cavity surface-emitting laser (VCSEL) that is an...
Briefs: Physical Sciences
In an alternative version of a proposed bimaterial thermal compensator for a whispering-gallery-mode (WGM) optical resonator, a mechanical element having nonlinear stiffness would be added to...
Briefs: Physical Sciences
Internal Water Vapor Photoacoustic Calibration
Water vapor absorption is ubiquitous in the infrared wavelength range where photoacoustic trace gas detectors operate. This technique allows for discontinuous wavelength tuning by temperature-jumping a laser diode from one range to another within a time span suitable for photoacoustic calibration. The...
Briefs: Information Technology
A recently developed method of constructing protograph-based low-density parity-check (LDPC) codes provides for low iterative decoding thresholds and minimum distances proportional to...
Briefs: Information Technology
Minimizing Input-to-Output Latency in Virtual Environment
A method and apparatus were developed to minimize latency (time delay) in virtual environment (VE) and other discrete-time computer-based systems that require real-time display in response to sensor inputs. Latency in such systems is due to the sum of the finite time required for information...
Briefs: Information Technology
PrimeSupplier Cross-Program Impact Analysis and Supplier Stability Indicator Simulation Model
PrimeSupplier, a supplier cross-program and element-impact simulation model, with supplier solvency indicator (SSI), has been developed so that the shuttle program can see early indicators of supplier and product line stability, while identifying the...
Briefs: Information Technology
Integrated Planning for Telepresence With Time Delays
A conceptual “intelligent assistant” and an artificial-intelligence computer program that implements the intelligent assistant have been developed to improve control exerted by a human supervisor over a robot that is so distant that communication between the human and the robot involves...
Briefs: Electronics & Computers
Battery Cell Voltage Sensing and Balancing Using Addressable Transformers
A document discusses the use of saturating transformers in a matrix arrangement to address individual cells in a high-voltage battery. This arrangement is able to monitor and charge individual cells while limiting the complexity of circuitry in the battery. The arrangement...
Briefs: Information Technology
Gaussian and Lognormal Models of Hurricane Gust Factors
A document describes a tool that predicts the likelihood of land-falling tropical storms and hurricanes exceeding specified peak speeds, given the mean wind speed at various heights of up to 500 feet (150 meters) above ground level. Empirical models to calculate mean and standard deviation of...
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