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Briefs: Mechanical & Fluid Systems
Flow Straightener for a Rotating-Drum Liquid Separator
A flow straightener has been incorporated into a rotary liquid separator that originally comprised an inlet tube, a shroud plate, an impeller, an inner drum, an outer drum, a housing, a pitot tube, and a hollow shaft motor. As a consequence of the original geometry of the impeller, shroud,...
Briefs: Manned Systems
Figure 1 shows a prototype of a large pressure vessel under development for eventual use as a habitable module for long spaceflight (e.g., for transporting humans to Mars). The vessel is a hybrid that comprises...
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Briefs: Information Technology
Finding Minimum-Power Broadcast Trees for Wireless Networks
Some algorithms have been devised for use in a method of constructing tree graphs that represent connections among the nodes of a wireless ommunication network. These algorithms provide for determining the viability of any given candidate connection tree and for generating an initial set...
Briefs: Information Technology
A scheme for resampling binaryimage data from a rectangular grid to a regular hexagonal grid and an associated tree - structured pixel - indexing scheme keyed to the level of resolution...
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Briefs: Electronics & Computers
Efforts are under way to apply the concept of evolvable hardware (EHW) to compensate for variations, with temperature, in the operational characteristics of electronic circuits. To...
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Briefs: Electronics & Computers
Polymorphic Electronic Circuits
Polymorphic electronics is a nascent technological discipline that involves, among other things, designing the same circuit to perform different analog and/or digital functions under different conditions. For example, a circuit can be designed to function as an OR gate or an AND gate, depending on the temperature...
Briefs: Electronics & Computers
Micro-Tubular Fuel Cells
Micro-tubular fuel cells that would operate at power levels on the order of hundreds of watts or less are under development as alternatives to batteries in numerous products — portable power tools, cellular telephones, laptop computers, portable television receivers, and small robotic vehicles, to name a few...
Briefs: Electronics & Computers
Analysis of SSEM Sensor Data Using BEAM
A report describes analysis of space shuttle main engine (SSME) sensor data using Beacon-based Exception Analysis for Multimissions (BEAM) [NASA Tech Briefs articles, the two most relevant being "Beacon-Based Exception Analysis for Multimissions" (NPO-20827), Vol. 26, No.9 (September 2002), page 32 and...
Briefs: Electronics & Computers
Instrumentation systems based on hairlike fiber-optic photochemical sensors have been proposed as minimally invasive means of detecting biochemicals associated with cancer and other diseases. The...
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Briefs: Electronics & Computers
Video Guidance Sensors Using Remotely Activated Targets
Four updated video guidance sensor (VGS) systems have been proposed. As described in a previous NASA Tech Briefs article, a VGS system is an optoelectronic system that provides guidance for automated docking of two vehicles. The VGS provides relative position and attitude (6-DOF) information...
Briefs: Electronics & Computers
Simulating Remote Sensing Systems
The Application Research Toolbox (ART) is a collection of computer programs that implement algorithms and mathematical models for simulating remote sensing systems. The ART is intended to be especially useful for performing design-tradeoff studies and statistical analyses to support the rational development of...
Briefs: Software
Simulation of Hyperspectral Images
A software package generates simulated hyperspectral imagery for use in validating algorithms that generate estimates of Earth- surface spectral reflectance from hyperspectral images acquired by airborne and spaceborne instruments.This software is based on a direct simulation Monte Carlo approach for modeling...
Briefs: Software
PVM Wrapper
PVM Wrapper is a software library that makes it possible for code that utilizes the Parallel Virtual Machine (PVM) software library to run using the message-passing interface (MPI) software library, without needing to rewrite the entire code. PVM and MPI are the two most common software libraries used for applications that involve...
Briefs: Software
Algorithm for Controlling a Centrifugal Compressor
Algorithm for Controlling a Centrifugal Compressor An algorithm has been developed for controlling a centrifugal compressor that serves as the prime mover in a heatpump system. Experimental studies have shown that the operating conditions for maximum compressor efficiency are close to the boundary...
Briefs: Physical Sciences
Solution-Assisted Optical Contacting
A modified version of a conventional optical-contact procedure has been found to facilitate alignment of optical components. The optical-contact procedure (called simply "optical contacting" in the art) is a standard means of bonding two highly polished and cleaned glass optical components without using epoxies...
Briefs: Mechanical & Fluid Systems
A method of reducing the noise generated by a tilt-rotor aircraft during descent involves active control of the blade pitch of the rotors. This method is related to prior such noise-...
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Briefs: Mechanical & Fluid Systems
It has been proposed to incorporate piezoelectric vibrational actuators into the structural supports of solar photovoltaic panels, for the purpose of occasionally inducing vibrations in the panels...
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Briefs: Physical Sciences
A mathematical model of a three-dimensional mixing layer laden with evaporating fuel drops composed of many chemical species has been derived. The study is motivated by the fact that...
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Briefs: Unmanned Systems
In the summer of 2001, the Helios prototype solar-powered uninhabited aerial vehicle (UAV) [a lightweight, remotely piloted airplane] was deployed to the Pacific Missile Range Facility...
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Briefs: Information Technology
Autonomous environment-monitoring networks (AEMNs) are artificial neural networks that are specialized for recognizing familiarity and, conversely, novelty. Like a biological neural network, an AEMN...
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Briefs: Information Technology
An improved method of computing a discrete approximation of the Laplacian of a Gaussian convolution of an image has been devised. The primary advantage of the method is that without...
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Briefs: Information Technology
Utilizing Expert Knowledge in Estimating Future STS Costs
A method of estimating the costs of future space transportation systems (STSs) involves classical activity-based cost (ABC) modeling combined with systematic utilization of the knowledge and opinions of experts to extend the process-flow knowledge of existing systems to systems that involve...
Briefs: Photonics/Optics
Advances in the development and manufacturing of photonic processors have reached a critical stage where their mass applications are becoming commercially viable. LNL...
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Briefs: Information Technology
More About the Phase-Synchroized Enhancement Method
A report presents further details regarding the subject matter of "Phase-Synchronized Enhancement Method for Engine Diagnostics" (MFS-26435), NASA Tech Briefs, Vol. 22, No. 1 (January 1998), page 54. To recapitulate: The phase-synchronized enhancement method (PSEM) involves the digital resampling...
Briefs: Photonics/Optics
A versatile and simple approach to the design and fabrication of curved-focal-plane arrays of silicon-based photodetectors is being developed. This approach is an alternative to...
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Briefs: Photonics/Optics
Under a DARPA program known as Steered Agile Beams (STAB), novel liquid-crystal devices are being developed by Rockwell Scientific Company (RSC) to...
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Briefs: Mechanical & Fluid Systems
Strain-Gauge Measurement of Weight of Fluid in a Tank
A method of determining the amount of fluid in a tank is based on measurement of strains induced in tank supports by the weight of the fluid. Unlike most prior methods, this method is nonintrusive: there is no need to insert instrumentation in the tank and, hence, no need to run wires, cables,...
Briefs: Manufacturing & Prototyping
A procedure now under development is intended to enable the precise alignment of sheet arrays of microscopic lenses with the end faces of a coherent bundle of as many as 1,000...
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Briefs: Medical
When a dog or cat breaks a bone, veterinarians often mend the fracture with a combination of stabilization devices called intra-medullary (IM) pins and external skeletal...
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