Special Coverage

Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space
Converting from Hydraulic Cylinders to Electric Actuators
Automating Optimization and Design Tasks Across Disciplines
Vibration Tables Shake Up Aerospace and Car Testing
Supercomputer Cooling System Uses Refrigerant to Replace Water

Flexible Structural-Health-Monitoring Sheets

A generic design for a type of flexible structural- health- monitoring sheet with multiple sensor/actuator types and a method of manufacturing such sheets has been developed. A sheet of this type contains an array of sensing and/or actuation elements, associated wires, and any other associated circuit elements incorporated into various flexible layers on a thin, flexible substrate. The sheet can be affixed to a structure so that the array of sensing and/or actuation elements can be used to analyze the structure in accordance with structural-health-monitoring techniques. Alternatively, the sheet can be designed to be incorporated into the body of the structure, especially if the structure is made of a composite material.

Posted in: Briefs, Mechanical Components, Mechanics, Aircraft structures, Sensors and actuators, Sensors and actuators, Vehicle health management, Composite materials
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Microgravity, Mesh-Crawling Legged Robots

These relatively inexpensive robots may be used in search and rescue operations.

The design, fabrication, and microgravity flight-testing are part of a continuing development of palm-sized mobile robots that resemble spiders (except that they have six legs apiece, whereas a spider has eight legs). Denoted SpiderBots (see figure), they are prototypes of proposed product line of relatively inexpensive walking robots that could be deployed in large numbers to function cooperatively in construction, repair, exploration, search, and rescue activities in connection with exploration of outer space and remote planets.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Product development, Fabrication, Robotics, Flight tests, Spacecraft
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Advanced Active-Magnetic-Bearing Thrust-Measurement System

Automatic multipoint calibration and a fringing model are used to increase accuracy.

An advanced thrust-measurement system utilizes active magnetic bearings to both (1) levitate a floating frame in all six degrees of freedom and (2) measure the levitation forces between the floating frame and a grounded frame. This system was developed for original use in measuring the thrust exerted by a rocket engine mounted on the floating frame, but can just as well be used in other force-measurement applications.

Posted in: Briefs, Mechanical Components, Mechanics, Measurements, Bearings
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Thermally Actuated Hydraulic Pumps

These pumps would contain no sliding (wearing) parts.

Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Pumps, Hydraulic fluids
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Purifying Nucleic Acids From Samples of Extremely Low Biomass

A new method is able to circumvent the bias to which one commercial DNA extraction method falls prey with regard to the lysing of certain types of microbial cells, resulting in a truncated spectrum of microbial diversity. By prefacing the protocol with glass-bead-beating agitation (mechanically lysing a much more encompassing array of cell types and spores), the resulting microbial diversity detection is greatly enhanced.

Posted in: Briefs, Bio-Medical, Medical, Biological sciences, Test procedures
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Adjustable-Viewing-Angle Endoscopic Tool for Skull Base and Brain Surgery

Surgeons could operate more precisely.

The term “Multi-Angle and Rear Viewing Endoscopic tooL” (MARVEL) denotes an auxiliary endoscope, now undergoing development, that a surgeon would use in conjunction with a conventional endoscope to obtain additional perspective. The role of the MARVEL in endoscopic brain surgery would be similar to the role of a mouth mirror in dentistry. Such a tool is potentially useful for in-situ planetary geology applications for the close-up imaging of unexposed rock surfaces in cracks or those not in the direct line of sight.

Posted in: Briefs, TSP, Bio-Medical, Medical, Medical equipment and supplies, Surgical procedures
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UV-Resistant Non-Spore-Forming Bacteria From Spacecraft-Assembly Facilities

Four species of non-spore-forming bacteria collected from clean-room surfaces in spacecraft-assembly facilities could survive doses of ultraviolet (UV) radiation that would suffice to kill most known cultivable bacterial species. In a previous study, high UV resistance was found in spores of the SAFR-032 strain of Bacillus pumilus, as reported in “Ultraviolet-Resistant Bacterial Spores,” NASA Tech Briefs, Vol. 31, No. 9 (September 2007), page 94. These studies are parts of a continuing effort to understand the survival of hardy species of bacteria under harsh conditions, and develop means of sterilizing spacecraft to prevent biocontamination of Mars that could in turn interfere with future life detection missions.

Posted in: Briefs, Bio-Medical, Medical, Environmental protection, Bacteria, Assembling, Radiation
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Near-Field Spectroscopy With Nanoparticles Deposited by AFM

It is not necessary to integrate an AFM with a spectrometer.

An alternative approach to apertureless near- field optical spectroscopy involving an atomic-force microscope (AFM) entails less complexity of equipment than does a prior approach. The alternative approach has been demonstrated to be applicable to apertureless near-field optical spectroscopy of the type using an AFM and surface enhanced Raman scattering (SERS), and is expected to be equally applicable in cases in which infrared or fluorescence spectroscopy is used.

Posted in: Briefs, Physical Sciences, Spectroscopy, Spectroscopy, Nanomaterials, Test equipment and instrumentation
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Simplified Modeling of Oxidation of Hydrocarbons

Only a few dozen molecular and radical species are included in calculations.

A method of simplified computational modeling of oxidation of hydrocarbons is undergoing development. This is one of several developments needed to enable accurate computational simulation of turbulent, chemically reacting flows. At present, accurate computational simulation of such flows is difficult or impossible in most cases because (1) the numbers of grid points needed for adequate spatial resolution of turbulent flows in realistically complex geometries are beyond the capabilities of typical supercomputers now in use and (2) the combustion of typical hydrocarbons proceeds through decomposition into hundreds of molecular species interacting through thousands of reactions. Hence, the combination of detailed reaction-rate models with the fundamental flow equations yields flow models that are computationally prohibitive. Hence, further, a reduction of at least an order of magnitude in the dimension of reaction kinetics is one of the prerequisites for feasibility of computational simulation of turbulent, chemically reacting flows.

Posted in: Briefs, TSP, Physical Sciences, Computational fluid dynamics, Hydrocarbons
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Hard-X-Ray/Soft-γ-Ray Imaging Sensor Assembly for Astronomy

A pixilated scintillator is coupled with an array of avalanche photodiodes.

An improved sensor assembly has been developed for astronomical imaging at photon energies ranging from 1 to 100 keV. The assembly includes a thallium-doped cesium iodide scintillator divided into pixels and coupled to an array of high-gain avalanche photodiodes (APDs). Optionally, the array of APDs can be operated without the scintillator to detect photons at energies below 15 keV. The array of APDs is connected to compact electronic readout circuitry that includes, among other things, 64 independent channels for detection of photons in various energy ranges, up to a maximum energy of 100 keV, at a count rate up to 3 kHz. The readout signals are digitized and processed by imaging software that performs “on-the-fly” analysis.

Posted in: Briefs, TSP, Physical Sciences, Architecture, Imaging, Imaging and visualization, Sensors and actuators, Architecture, Imaging, Imaging and visualization, Sensors and actuators, Radiation
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