Abstract: A position tracker uses an inertial angular measurement system, for measuring orientation and linear translation of a helmet on a human head for the synthesis by a host computer of virtual, directional audio over headphones sensors mounted on the helmut, includes a roll gyro sensor, a pitch gyro sensor, a yaw gyro sensor, an absolute roll tilt sensor coupled to a first universal signal conditioner, an absolute pitch tilt sensor coupled to a second universal signal conditioner, and an absolute yaw compensator. A data acquisition system is coupled between the sensors and the host computer for converting analog signals from the sensors into digital, angular orientation data. Each of the gyro sensors includes angular velocity detectors and solid state electronic devices connected to provide angular velocity signals at a given sample rate.

Abstract: A method for controlling the interface in a composite between the matrix material and reinforcing filaments or fibers in a composite structure which comprises the application of a patterned coating or combination of coatings on the reinforcing filaments or fibers to vary the bond between the reinforcement and the matrix. Proportioning of weak- and strong-bonded areas, their respective strengths, and design of bonding patterns can be tailored to the materials requirements of the composite.This method can be employed to prepare metal, ceramic and polymer matrix composites.

Abstract: An aircraft electrical supply bus supplementing arrangement in which electrical energy is stored in a large capacitor and energy flow between the capacitor and the bus is controlled by a bi-directional electrical converter circuit of the switched inductance type. The varying terminal voltage of the energy storing capacitor, a super capacitor, is coupled to the relatively fixed voltage of the aircraft supply bus by way of the voltage changing capability of the converter circuit switched inductance. Current flow levels in this inductance are controlled with a negative feedback regulator circuit. Energy storage efficiency in the converter is enhanced with respect to weight and physical size of the capacitor element by ability of the converter circuit to accept a widely varying input voltage while generating a relatively constant output voltage.

Abstract: A fire suppression system for the engine compartment of a vehicle is described which includes a remotely controllable throttle valve disposed within the exhaust duct of the engine for selectively diverting exhaust gases through a bypass duct for mixing with the ventilation airflow for the purpose of reducing the oxygen content in the airflow over the engine below a level which will effectively support combustion.

Abstract: An aryletherketone copolymer having repeating units of the formula: ##STR1## wherein the ratio m:n is in the range of 1:99 to 99:1; wherein Ar is selected from the group consisting of: ##STR2## and wherein Ar' is selected from the group consisting of ##STR3## wherein Q is --O--, --CH.sub.2 -- or --CO--, is useful in the dispersion of active NLO chromophores containing a basic functionality to form optically clear films.

Abstract: A multiresolution, multirate approach for detecting and following targets. The resolution of data obtained from a target scanning region is reduced spatially and temporally in order to provide to a tracker a reduced amount of data to calculate. Balances of computer processing resources with long-range detection and multiple target tracking are provided. Computer processing resources can be allocated to other systems while still maintaining an accurate tracking function and alternatively, the tracking function can receive a high level of computer processing resources and track at a finer resolution. An ability to recover raw data points from the spatially and temporally reduced values is also provided.

Abstract: An aryletherketone polymer having repeating units of the formula: ##STR1## wherein Ar is selected from the group consisting of ##STR2## wherein Q is --O--, --CH.sub.2 -- or --CO--, is useful in the dispersion of active NLO chromophores containing a basic functionality to form optically clear films.

Abstract: A transmission line arrangement providing control of signal losses through the use of conductor cross-sectional surface area-increasing and skin effect-considered bulbous additions to the rectangular conductor cross-sectional shape frequently used in semiconductor device transmission line conductors. The achieved transmission line is especially suited for use in radio frequency integrated circuit assemblies where it also includes a backplane member, encounters signals in the microwave and millimeter wavelength range and involves conductor dimensions measured in micrometers. Control of transmission line characteristic impedance at, for example, 50 ohms is disclosed as is use of semiconductor device-compatible materials and loss comparisons data.

Abstract: A practical, low-energy consumption method of performing an N-point fast rier transform employing mathematically justified manipulation of input data, multirate, parallel and asynchronous circuit techniques. The multirate feature allows an input data sequence to be broken down into its polyphase components. The polyphase components can then be operated upon in a local and parallel manner. Localizing and minimizing loads of a circuit allows operations to be performed only when necessary in an asynchronous manner. The energy consumed in performing an N-point fast Fourier transform of the present invention is less than half that of known systems employing global memory and clocked methodologies. The feature of low energy consumption makes the invention attractive for use in hand-held audio/video devices where energy requirements can be met with a low rate of battery replacement.

Abstract: A method for fabricating a dental restoration is described which comprises the steps of obtaining a dental impression of a patient using dental impression material, filling the cavity defining the impression with a filler material distinguishable from the dental material defining the impression and allowing the materials to harden to a solid block, successively removing from the block thin layers and imaging each then remaining surface of the block after each successive layer is removed to define a contour of the filler material for each layer removed, each contour corresponding to a contour of the teeth, gums and palate of the patient at a corresponding known depth of the block, generating a three dimensional computer model of the teeth, gums and palate of the patient using the contours, and converting the model to a stereolithography file for producing a castable pattern of the model or machining a restoration corresponding to the model.

Abstract: Gas generator apparatus usable with a ducted rocket propellant having a high exponent burn rate, a burn rate that is burn chamber pressure sensitive to a greater degree than are normally used propellants. The gas generator includes elementary pressure regulating elements and apparatus for damping movement of the pressure regulating elements to remove oscillatory components of motion therefrom. Burn rate operating point determination and the stability characteristics thereof are described along with the effects of variations in propellant burn rate exponent and regulating element parameters.

Abstract: An air-cooled gas turbine blade providing improved cooling characteristics is disclosed. The turbine blade includes several internal passages for conveying cooling air therethrough during turbine operation to provide the desired cooling effect. Two distinct passages are provided to cool the airfoil leading and trailing edges, respectively. Two serpentine cooling passages are disposed so as to efficiently cool each side of the airfoil. Disposed in the middle of the airfoil is an additional, distinct passage. The platform is cooled by three serpentine cooling passages. Two of these passages are in outlet fluid communication with the inlet to the middle airfoil passage. As cooling air traverses these two passages, heat is transferred, from the base simultaneously cooling it and warming the air. This warmed air is next directed through the middle airfoil passage, providing a slight warming effect to the center portion of the airfoil.

Abstract: A high voltage high current semiconductor switching device in which the tendency to incur premature electrical breakdown through carrier channels formed slightly below the surface of the semiconductor material is avoided. This avoidance occurs through use of a current dispersing electrically insulating element added at one extremity of the switching device structure. The added current dispersing element may be in the form of a thin oxide layer added at the anode end of the device in the case of a silicon embodiment of the invention. Tunneling conduction is believed to occur in this silicon dioxide layer and such conduction has the effect of dispersing the current through the silicon over a cross-sectional area sufficiently large to prevent the current filamentation, localized heating, thermal runaway and self destruction sequence often encountered in previous arrangements of higher energy semiconductor switches.

Abstract: A fiber reinforced composite structure and method for fabricating the composite, are described wherein four sets of mechanically flexible fibers are interwoven in a three-dimensional woven structure wherein each fiber is woven through the structure generally along one of the four directions defined generally parallel to a body diagonal of a cube, and wherein the woven structure is impregnated with polymeric, metallic or ceramic matrix material to form a composite material which is braced against deformation by shear applied in any orientation.

Abstract: A photo FET device having a large area backside optical energy reception surface is disclosed. The photo FET device is fabricated in the source gate and drain upward configuration and then inverted onto a new permanent substrate member and an original surrogate substrate member removed in order to expose the active area backside optical energy reception surface. Electrical characteristics including curve tracer electrical data originating in both dark and illuminated devices and devices of varying size and both depletion mode and enhancement mode operation are also disclosed. Fabrication of the device from gallium arsenide semiconductor material and utilization for infrared energy transducing in a number of differing electronic applications are also disclosed.

Abstract: The present invention is a calibration system that allows one person to perform multiple end-to-end calibrations of a structural dynamic measurement system including mounted transducers, signal conditioning and recorder. Only one person is needed to operate the system at the recorder. The system stimulates structural measurement transducers contained inside of structures using remotely controlled exciters with a measurable acceleration level and the data measured by the transducers is communicated to a recorder.

Abstract: A cell culture device is described comprising a gas permeable vessel which contains one or more self contained carbon dioxide generators and which is attached to a closure closing a gas permeable cell culture flask. Located in the closure is a gas permeable insert which defines a gas permeable opening through which the gases from the atmosphere of the vessel produced by the carbon dioxide generators can communicate with the gases in the atmosphere of the flask. This invention allows the rapid and uniform equilibration of the atmosphere of the flask with the controlled atmosphere of the vessel while still providing a closed system which prevents the entry of microbial organisms into the flask. This invention provides a controlled atmosphere for up to 24 hours that maintains the pH of the culture medium for optimal growth of cells growing in the culture medium in the flask.

Abstract: A periodic table group III-IV metal semiconductor metal field-effect transistor device is described. The disclosed device includes single metalization for ohmic and Schottky barrier contacts, an elective permanent etch stop layer, a non-alloyed ohmic contact semiconductor layer and a permanent non photosensitive secondary mask element. The invention may be achieved with one of an all optical lithographic process and a combined optical and electron beam lithographic process The disclosed field-effect transistor device is of reduced fabrication cost, increased dimensional accuracy and state of the art electrical performance.

Abstract: A new apparatus and method for irrigating wounds and for performing gastric lavage utilizes a novel cap that has a threaded end sized to screw onto available plastic bottles of sterile irrigation fluid or saline and a nozzle end having the shape of a syringe tip. The threaded end of the cap is screwed onto the plastic bottle of irrigation fluid and an intravenous (IV) catheter attached to the nozzle end. The plastic bottle of irrigation fluid is held and squeezed to direct a stream of irrigation fluid through the IV catheter and into the wound. For gastric irrigation, a nasogastric tube is attached to the nozzle end and the bottle of irrigation fluid held and squeezed to force irrigation fluid into the stomach.

Abstract: A method for producing a pattern for making a cast part is described which comprises the steps of defining the structure of the part in terms of computer aided design system data, selecting a parting surface for the part to be cast; defining core requirements for the part by sweeping each positive feature of the part to the parting surface, subtracting the part from the projection, adding any remaining volume to the core, sweeping negative features away from the parting surface to the top or bottom of the mold and subtracting the negative features from the projection and intersecting the remainder of the part and adding any remaining volume to the core; repetitively generating alternative parting surfaces for the part and defining the corresponding core requirements whereby an optimum parting surface is defined for which the quantity and complexity of the corresponding core requirements are minimized, constructing core prints for each core requirement; constructing a pattern by adding the core prints to the p