2,070,599 research outputs found

    Tactile sensing means for prosthetic limbs

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    An improved prosthetic device characterized by a frame and a socket for mounting on the stump of a truncated human appendage is described. Flexible digits extend from the distal end and transducers located within the digits act as sensing devices for detecting tactile stimuli. The transducers are connected through a power circuit with a slave unit supported by a strap and fixed to the stump. The tactile stimuli detected at the sensing devices are reproduced and applied to the skin of the appendage in order to stimulate the sensory organs located therein

    Low energy ohmmeter can be used to test sensitive circuits, other meters

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    Hazardous circuit ohmmeter is of sufficiently low energy output that it may be used to test extremely sensitive circuits safely, reliably, and accurately. A polyurethane-foam-lined aluminum case provided protection for the unit assembly

    Circuit board hole coordinate locator concept

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    Fixed light source registers the x and y coordinates of holes in a fixed opaque template. A first surface parabolic mirror and a set of photocells are used to detect the passage of light through the individual holes

    Coaxial anode improves sensitivity of gas radiation counters

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    Anode wire itself is enclosed by three segments. Two on ends are rejector segments, and middle one is primary charge-detecting segment. Anode wire is made from tungsten and is surrounded by enamel insulation. Enamel is covered by segments of vapor-deposited gold. At one point in center segment, gold layer makes direct contact with anode wire

    Systems for dead-reckoning navigation and for simulation of instrumental error - Concepts

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    Navigational system for manned lunar vehicles is intended for travel totaling 30 km within 5 km of home base, total distance traveled must be indicated with 2 percent accuracy. Hardware includes two two-degrees-of-freedom gyroscopes, odometers, tachometers, and signal processing equipment

    Wideband Channel Estimation and Prediction in Single-Carrier Wireless Systems

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    Abstract—In this contribution wideband channel estimation and prediction designed for single-carrier wideband wireless communications systems are investigated. Specifically, the single-carrier wideband pilot signal received by the receiver is first converted to the frequency-domain. Then, the envelope of the channel transfer function (CTF) is estimated in the frequency-domain, in order to reduce the effects of background noise on the channel prediction step to be invoked. Finally, channel prediction is carried out based on the estimated CTF in the frequency-domain, where a Kalman filter assisted long-range channel prediction algorithm is employed. Our simulation results show that for a reasonable signal-to-noise ratio (SNR) value the proposed frequency-domain based wideband channel estimator is capable of efficiently mitigating the effects of the background noise, hence enhancing the performance of wideband channel prediction

    Thermal Decomposition of Some Linear Perfluoroalkanes in an Inconel Tube

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    The products of the pyrolysis reactions of perfluoropropane, perfluoroethane, and carbon tetrafluoride in an Inconel bomb are described. The values for the energy of activation and frequency factor for the first-order pyrolysis reactions are respectively: (1) 80 kcal. per mole and 2x10(exp14) sec.(exp-1) for perfluoropropane; (2) 53 kcal. per mole and 3x10(exp7) sec.(exp-1) for perfluoroethane; and (3) 96 kcal. per mole and 4x10(exp13) sec.(exp-1) for carbon tetrafluoride

    Gregorian all-reflective optical system

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    An optical heterodyne receiver comprises a system of reflectors forming a folded Gregorian configuration for collecting a signal beam, and an optical detector located at the focus of the system. A paraboloidal primary reflector and an elipsoidal secondary reflector face each other on an optical axis with the focus of the secondary reflector coinciding with the focus of the primary reflector. An auxiliary laser generates a local oscillator beam that is combined with the signal beam after the signal beam emerges from the exit pupil (which is also the aperture stop) of the system, and the resultant is impinged on the detector. A pair of image motion compensators is located as close to the exit pupil as possible for aligning off-axis inputs to the detector

    Self-protected electrodes limit field-emission current

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    One cathode includes array of square-shaped conductor columns. Columns are electrically interconnected by conducting plate on bottom. Each column provides field-emission current. Another cathode includes array of rodlike conductors. Layer is covered by control film made of conducting material. Film is isolated from each conductor

    Manual of industrial diamonds plus dressing and grinding criteria for machining superalloys

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    Manual combines the important and controlling factors for the proper selection and use of diamond stones for cutting and dressing grinding wheels. This manual is a compilation of empirical data and incorporates an original companion treatise on the physical descriptions of the diamond stones, their grading, and their applications
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