Abstract: A bi-directional power converter for cryogenic operation based on a bi-directional cryo-MOSFET switch. Cryogenic power electronics lends itself easily to bi-directional topologies, and brings higher efficiencies, further reductions in switching speed, higher-frequency operation, reduction in size and weight of associated transformers and inductors, and reductions in overall size and weight. In addition, cryogenic power electronics operating around liquid nitrogen temperatures is easily integrated with superconducting motors, motor drives, and transformers, all of which can reduce size and weight of shipboard power systems, allowing for greater payload.

Abstract: An ultra compact ring topology puts the output terminals of solid state switches physically at the center of a circuit with the switches surrounded by voltage busses. The switches are symmetrically arranged around the output bus, the voltage busses are filtered (decoupled) to ground using symmetrically positioned filter components, and lead lengths to and from the switches are minimized. Switch driver circuits are closely integrated with each switch and positioned as close as possible, each to its associated switch, and arranged symmetrically. Switches may be at cryogenic temperatures and busses and lead connectors may be superconductive.

Abstract: This invention describes a means by which lasers and laser beam controllers mounted on moving vehicles or other unstable platforms can be isolated from vibrations. By magnetically levitating the entire laser or just the beam controller hardware, targeting efficiency can be vastly improved. Superconducting levitation and control coils can be used to reduce added power losses. Cryogenic power conversion systems can be employed to drive the levitation system. The laser could also be cryogenically cooled, depending on the type of laser employed.

Abstract: This invention describes a means by which performance characteristics of capacitors can be improved. This is achieved by reducing the temperature, preferably but not exclusively to cryogenic temperatures below 100 K. The dielectric strength, dielectric losses, equivalent series resistance, and plate losses in many capacitors, such as film capacitors, improve as the temperature is decreased. Current carrying capacity is improved. A capacitor bank exhibits energy densities up to four times those of conventional, room-temperature capacitor banks. Cryogenic capacitors can be combined with cryogenically operated semiconductors or with superconductors to reduce the size, weight, and losses of a complete system.

Abstract: An electrical switching topology for a hybrid switch provides extremely low losses in both cryogenic and non-cryogenic electronic systems. In this switch having switch modules connected in parallel, switching losses in a first module are separated from conduction losses in the parallel-connected second module. The conduction losses are then further reduced by cryogenically cooling the second module. Since the switching losses of the first module can be absorbed outside a cryogenic container, the switching losses do not add to the cryogenic heat load. In other applications, the switching module operates at lower temperatures to provide higher switching speeds and reduces switching heat generation.

Abstract: A method uses body images and computer hardware and software to collect and analyze clinical data in patients experiencing pain. Pain location information is obtained by the drawing of an outline of the pain on a paper copy or electronic display of the body image. Composite images are generated representing aggregate data for specified patient groups. The coordinates of common anatomic landmarks on differently designed body images are mapped to each other, permitting integrated analysis of pain data, e.g., pain shape, centroid, meta centroid, from multiple body image designs and display of all pain data on a single body image design. Differences and similarities between groups of patients are displayed visually and numerically, and are used to assign the probability of a given patient belonging to a particular diagnostic group or category of disease severity.

Abstract: A detachable superconducting lead includes a vacuum-sealed thermal transition through which a stabilized conductor passes. Two identical leads are attached and surrounded by a sealed Dewar and allowed to cool either naturally or by way of a cooling element. Detaching the leads requires the joint to be heated up by a heat transfer unit or by a heat gun after the Dewar is removed. Once warmed, the lead can be disassembled with tooling appropriate to the joint. In many instances, regular fasteners can be used. Removable Dewars may be constructed with insulation (including vacuum) using O-rings and flanges.

Abstract: Switching losses and conduction losses are isolated by networks which are partially cryogenic and partially at room temperature. Switching losses are independent of temperature. Advantageously the switching losses are taken in a snubber network at room temperature and conduction losses are incurred at cryogenic temperatures, where majority carrier devices like MOSFETs operate with ultra low on-state resistance and corresponding low conduction losses. Low loss leads carry current efficiently from the cryogenic environment to room temperature without adversely affecting refrigeration. Switch and snubber network may both operate cryogenically.

Abstract: The highest-power switches now available are based on thyristor-type devices: GTOs (Gate turn-off thyristors), MTOs (MOS controlled turn-off thyristors), IGCTs (Integrated gate commutated thyristors), and the new ETOs (Emitter turn-off thyristors). These devices handle kilovolts and kiloamperes for megawatt inverters/converters. Measurements by the inventors show that conduction losses of MOSFETs and switching losses of IGCTs are drastically decreased by cryo-cooling. IGCTs, ETOs, and MTOs, together with many small, low voltage MOSFETs for gate and emitter turn-off circuitry, are cryo-cooled to attain much higher switching speeds and a reduction in size, weight and cost of high-power (megawatt range) equipment.

Abstract: A method and apparatus for reducing conductive thermal losses in high-current cryogenic power electronics systems needing large cables to interface between warm and cold environments. Thermal losses increase with increasing cross-sectional area. The total current at the warm/cold interface is split into many smaller currents by splitting the power buss into a plurality of parallel leads. Respective physical switches in each smaller lead at the interface interrupt current flow, and at the same time open the path for thermal conduction along the lead. When little or no current is flowing through the system, selected smaller leads of the power buss are physically opened by the associated switches to stop the thermal and electrical flow along these leads. Current diverts to another parallel lead in the buss but the cross section for heat flow is reduced at the interface.

Abstract: This invention describes a means by which performance characteristics of capacitors can be improved. This is achieved by reducing the temperature, preferably but not exclusively to cryogenic temperatures below 100 K. This is based on the observation that the dielectric strength, dielectric losses and plate losses in many capacitors, such as film capacitors, improve as the temperature is decreased. A cryogenic capacitor bank is also described, which exhibits energy densities up to four times those of conventional, room-temperature capacitor banks. Cryogenic capacitors can be combined with cryogenically operated semiconductors or with superconductors in such a way as to reduce the size, weight, and losses of a complete system.

Abstract: Losses are reduced in electrical conductors and filters, especially those made with superconducting cables or inductors, which carry currents having both direct current (DC) and alternating current (AC) portions as in rectifier busses and power distribution systems. Superconducting cables and chokes are capable of passing direct current with practically zero losses, but they exhibit considerable AC losses. A low impedance AC bypass of the superconducting cables and chokes minimizes these losses.

Abstract: Sub-systems and components of a MRI system have enhanced electrical efficiency, faster operation, reduced physical metrics, by operating at cryogenic temperatures and/or incorporating superconducting elements. A plurality of sub-systems and a super-conducting magnet are enclosed in a common Temperature-controlled chamber. Resistive or permanent magnets may be used in place of the superconductive magnet.

Abstract: Magnetic resonance force microscopy (MRFM) is a technology capable of detecting the magnetic resonance of a small number of spins and, potentially, a single spin of an electron or nucleus. Most methods use soft cantilevers with microscopic dimensions (microns) which have been developed for atomic force microscopy. Cantilevers have been both a solution and problem of high sensitivity force detection. They are difficult to fabricate and it is difficult to achieve the right sensitivity and stiffness with them. The proposed invention eliminates the cantilever and replaces it with small, magnetically sensitive objects called birdies, which are manipulated above a sample using electromagnetic field control. The basic principles of the cantilever-free MRFM are the same as those of traditional, cantilever-based systems. Motion of the birdie induced by magnetic resonance is monitored using optical interferometry.

Abstract: The ski pole has normal strength when the pole is normally gripped at its handle and reduced strength when not gripped. The poles permanently deform when a predetermined level of excessive bending force is applied. The pole shaft is hollow with a short circumferential segment having reduced cross-section. When the handle is gripped, a plug slideable within the shaft spans the reduced cross-section and reinforces the pole at that region. When the handle is not gripped, the plug slides away from the reduced wall segment and reduces pole strength. A button on the handle connects to the plug by a rod, cable, hydraulics, pneumatics, etc. Alternatively, button actuation electrically drives a magnetic solenoid to move the plug. The weakened portion is replaceable so the pole is reusable.

Abstract: A cryogenic power conditioning system for fuel cells is proposed which is cooled by liquid hydrogen or liquid natural gas (methane) used to power these fuel cells, or by liquid nitrogen supplied by high-temperature superconducting cables. The main applications are in large vehicles such as transit buses. The result is a combined motor and motor-drive system exhibiting higher efficiency, lower weight, smaller size and lower cost.

Abstract: A plurality of strips are releasably interconnected to a support bar as an assembly for mounting a shutter within a window frame. Male and female connectors such as tongue and groove or pin and socket connectors interconnect the strips to one another and to the support bar. The strips, located between the bar and the window frame, may be manually added or removed from the support bar by transverse motion individually with a low force to adjust the width of the shutter mounting assembly to fit the shutter to window frames of various widths without need for tools.

Abstract: A SLC has a thin brittle ceramic dielectric layer less than 0.0035 inches thick and as low as 0.0005 inches or less. Electrodes are thick and strong enough either singly or together to give the structure required physical strength for manufacture, handling, and usage. Electrodes are (1) a ceramic metal composite, (2) a porous ceramic infiltrated with metal or other conductive material, (3) a resin filled with metal or other conductive material, or (4) combinations of the above. The very thin and, in itself, fragile dielectric layer provides exceedingly high capacity per unit area with temperature stability and low losses. A 0.00001-inch thick dielectric of titanium dioxide is also used.

Abstract: A cord tensioned by a spring supports the sash of a hung window in a stationary position while the sash is tilted for cleaning. The cord pulls a pulley attached to the spring which extends as the sash is further tilted. A tubing houses the spring and pulley and provides a stop that limits the maximum tilt of the sash.

Abstract: Combining an implant and cement for prophylactic and/or preventative use for femoral neck augmention. A hole is drilled into the femoral neck. The hole is filled with an uncured filler cement after loose materials have been removed from the hole. Then, an open-ended tube, an implant, having openings through its walls is inserted into the hole and attached to the bone. Finally, additional filler cement is provided under pressure to the inside of the tubular implant. The filler cement flows into spaces in the bone structure via the tube wall openings. A sliding leak-tight fit between the implant and a cement injection tube permits delivery of cement at preselected locations along the implant length. Pressure is maintained until the filler cement has hardened. A strengthening factor up to 3 was measured when osteoporotic bone was strengthened.