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High-Temperature SMAs for Actuator Applications

Work output is comparable to conventional SMA alloys but with transition temperatures significantly exceeding those of conventional materials. Compositions and production processes have been developed for making NiTi-based shape-memory alloys (SMAs) that can be tailored for use as actuator materials at temperatures exceeding those of conventional alloys. Whereas conventional shape-memory alloys are limited to use at temperatures well below 100 °C due to low transformation temperatures, these high-temperature shape-memory alloys (HTSMAs) have transformation temperatures exceeding 300 °C while maintaining many of the other attributes associated with NiTi alloys, most importantly high work output (see Figure 1). Other attractive properties of this family of NiTiPt HTSMAs include usefully high values of tensile ductility, relatively narrow hysteresis, good oxidation resistance up to 600 °C, and excellent thermal and dimensional stability. Just as important, these alloys can be readily processed into various structural forms such as thin rod and fine-diameter wire by conventional processes (see Figure 2). These materials hold promise for expanding the variety of applications in which SMAbased actuators could be used.

Posted in: Briefs, TSP

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LiCoPO4 Cathode Layers for Thin-Film Batteries

Highest voltage thin-film batteries ever reported are demonstrated at low current densities. LiCoPO4 has been found to be a promising active cathode material for high-energy-density, thin-film, rechargeable electrochemical power cells. The potential of the charge/discharge plateau of a cell containing an LiCoPO4 cathode is 4.8 V — a value that compares favorably with the corresponding value of 3.8 V of a state-of-the art cell containing an LiCoO2 cathode.

Posted in: Materials, Briefs, TSP

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Ski Binding Prototype Designed and Tested with FEA Software

Weight and strength of plastic and metal components were optimized with finite-element analysis. G3 Genuine Guide Gear (G3) of North Vancouver, British Columbia, Canada, is a specialized manufacturer of backcountry ski and safety equipment — including telemark bindings and accessories, climbing skins, and shovels and saws — designed for guides and avalanche professionals.

Posted in: Briefs

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Split-Block Waveguide Polarization Twist for 220 to 325 GHz

This device is superior to conventional twisted rectangular waveguides for submillimeter wavelengths. Figure 1. A Channel Having Asymmetric Steps is cut into the lower block.An identical channel is cut into the upper block. Then with the help ofalignment pins, the blocks are assembled so that the two channels mergeinto one channel that makes a transition between two orthogonal orientationsof a WR-3 waveguide.A split-block waveguide circuit that rotates polarization by 90° has been designed with WR-3 input and output waveguides, which are rectangular waveguides used for a nominal frequency range of 220 to 325 GHz. Heretofore, twisted rectangular waveguides equipped with flanges at the input and output have been the standard means of rotating the polarizations of guided microwave signals. However, the fabrication and assembly of such components become difficult at high frequency due to decreasing wavelength, such that twisted rectangular waveguides become impractical at frequencies above a few hundred gigahertz. Conventional twisted rectangular waveguides are also not amenable to integration into highly miniaturized subassemblies of advanced millimeter- and submillimeter- wave detector arrays now undergoing development. In contrast, the present polarization-rotating waveguide can readily be incorporated into complex integrated waveguide circuits such as miniaturized detector arrays fabricated by either conventional end milling of metal blocks or by deep reactive ion etching of silicon blocks. Moreover, the present splitblock design can be scaled up in frequency to at least 5 THz.

Posted in: Briefs, TSP

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WRATS Integrated Data Acquisition System

This new system substantially improves tiltrotor aeroelastic test methods. The Wing and Rotor Aeroelastic Test System (WRATS) data acquisition system (DAS) is a 64-channel data acquisition display and analysis system specifically designed for use with the WRATS 1/5-scale V-22 tiltrotor model of the Bell Osprey. It is the primary data acquisition system for experimental aeroelastic testing of the WRATS model for the purpose of characterizing the aeromechanical and aeroelastic stability of prototype tiltrotor configurations. The WRATS DAS was also used during aeroelastic testing of Bell Helicopter Textron’s Quad-Tiltrotor (QTR) design concept, a test which received international attention. The LabVIEW-based design is portable and capable of powering and conditioning over 64 channels of dynamic data at sampling rates up to 1,000 Hz. The system includes a 60-second circular data archive, an integrated model swashplate excitation system, a moving block damping application for calculation of whirl flutter mode subcritical damping, a loads and safety monitor, a pilot-control console display, data analysis capabilities, and instrumentation calibration functions. Three networked computers running custom-designed LabVIEW software acquire data through National Instruments data acquisition hardware.

Posted in: Briefs

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Heating Different Zones of Food in a Microwave Oven

An organization seeks technology to enable foods to become crispy when heated in a home microwave oven. The outer surface should heat and become (or remain) crispy, while the interior body of the food should heat only as appropriate. The organization seeks materials, ingredients, or other technologies that enable the zones, while physically part of the same food, to respond differently to the same radiant microwave energy environment. Respond to this TechNeed at: Email: nasatech@yet2.com Phone: 781-972-0600

Posted in: NASA Tech Needs

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Topical Delivery for Analgesic Medications

A company seeks new non-oral delivery mechanisms for analgesics. Non-oral methods avoid the stomach and the intestine. These new mechanisms might be topical; that is, in contact with the outer layer of the skin. However, other nonoral mechanisms are open for consideration. Non-oral administration bypasses both the stomach and the liver and can deliver more active to the bloodstream more quickly per dose. Respond to this TechNeed at: Email: nasatech@yet2.com Phone: 781-972-0600

Posted in: NASA Tech Needs

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