Abstract: A susceptor assembly comprises a generally planar susceptor having an electric field director structure mechanically connected thereto. The field director structure includes at least one, but more preferably, a plurality of two or more vanes mechanically connected to the susceptor. Each vane has a surface at least a portion of which is electrically conductive. The vane(s) are most preferably disposed substantially orthogonal to the planar susceptor. The connection may be either a fixed or a flexible articulating connection. In use, such as in the presence of a standing electromagnetic wave generated within a microwave oven, only an attenuated electric field component of the electromagnetic wave exists in a plane tangent to the surface of the vane in the vicinity of the conductive portion of the vane.

Abstract: A rotary transformer for coupling electrical power at a high level into a rotor operable at a high rotational speed without the introduction of undesirable electromagnetic torque and problems of dynamic mechanical instability comprises a stationary primary mounted in surrounding relationship with respect to the rotor, an electromagnetic shield having an exterior surface thereon mounted to the rotor, and a secondary mounted on the exterior surface of the shield. The secondary is connected in an electrical circuit with the load such that the application of an alternating current having a frequency of at least one (1) kilohertz to the primary produces an alternating electromagnetic field having flux lines in the secondary in the secondary oriented generally parallel to the axis of rotation. The alternation of the electromagnetic field induces a voltage in the secondary that generates an electric current to the load.

Abstract: Elevated temperature, gas-phase, catalyzed processes for preparing HCN in which induction heating is used as a source of energy, and novel apparatus for carrying out said processes.

Abstract: Disclosed are conductive polymeric materials comprising a resin-based structural material loaded with micron conductive fibers and/or micron conductive powders or to provide a conductive thermoplastic composition rather than an insulator. Also disclosed are antennas comprising the conductive thermoplastic compositions and methods for their fabrication.

Abstract: Disclosed are conductive polymeric materials comprising a resin-based structural material loaded with micron conductive fibers and/or micron conductive powders or to provide a conductive thermoplastic composition rather than an insulator. Also disclosed are antennas comprising the conductive thermoplastic compositions and methods for their fabrication.

Abstract: Elevated temperature, gas-phase, catalyzed processes for preparing HCN in which induction heating is used as a source of energy, and novel apparatus for carrying out said processes.

Abstract: This invention relates to improvements in processes and catalysts for elevated temperature, gas phase, catalyzed reactions in general; it is particularly illustrated by reference to the manufacture of hydrogen cyanide.

Abstract: Hydrogen cyanide is produced by reacting ammonia and a hydrocarbon gas in the presence of a platinum-group-metal catalyst while the catalyst is heated by induction heating at a frequency of 0.5 to 30 MHz.

Abstract: An improved induction heated reactor apparatus involving a reaction zone with inlet and outlet and containing an array of electrically conductive catalyst entities (susceptor entities) comprising pellets, rings, or rods containing a core externally coated with a substantially uniform and complete catalyst metal (e.g., platinum, platinum-iridium alloy, or platinum-rhodium alloy) wrap, coating, or surface impregnated, or containing the catalyst metal as a foam which are inductively heated to produce chemical product from a catalytic reaction. Such an apparatus is particularly useful in the catalytic generation of HCN at elevated temperatures.

Abstract: The present invention provides a method and apparatus for agitation-free, low temperature drying of fragile, temperature sensitive, granular materials at atmospheric pressure using Radio Frequency (RF) energy to provide the heat of evaporation. A relatively low velocity flow of purge air through either a continuously moving or stationary product bed provides means for removing moisture from the product at atmospheric pressure. The purge air is maintained at a controlled humidity, temperature and velocity, and the intensity of the RF field is controlled in response to temperature sensing means to control the temperature of the product. For the case of a continuously moving product bed the RF applicator is preferably divided into multiple zones, which may be independently controlled, to effect control of the moisture and temperature profile of the product as it passes through the apparatus.

Abstract: An apparatus and process for production of HCN from ammonia and a hydrocarbon gas by the use of microwave energy using a single mode microwave reactor.

Abstract: An apparatus and process for production of HCN from ammonia and a hydrocarbon gas by the use of microwave energy using a single mode microwave reactor.

Abstract: In a magnetic resonance imaging apparatus, a first frequency radio signal source (20a) is connected in quadrature with a four fold symmetric birdcage coil (24) at 90.degree. spaced connection points (80a,b). A source of a second radio frequency signal is directly connected with the birdcage coil by first and second inductive couplings (70a,b). The birdcage coil includes tank circuits (52) and capacitors (58, 60) in the end connectors. The capacitance of the end connectors is simultaneously adjustable by a tuning ring (62) to adjust a first resonance frequency of the coil and the capacitance of the tank circuits is selectively adjustable to adjust a second resonant frequency of the birdcage coil. In this manner, the birdcage coil is simultaneously tuned to two frequencies and can operate in quadrature at either one.

Abstract: A thin dielectric sheet (36) has a first or loop coil (30) defined on one surface thereof and a second or Helmholtz coil (32) defined on an obverse surface thereof. The dielectric sheet and associated coils may be laid flat (FIG. 3) or bent to match a selected curved surface of the subject (FIGS. 6-8). The first and second coils are arranged symmetrically about an axis or plane of symmetry (34). The first coil has an associated magnetic field along a y-axis and the second coil has an associated magnetic field along the x-axis. Circuits (40 and (42) tune the first and second magnetic resonance coils to a preselected magnetic resonance frequency. Magnetic resonance signals of the selected frequency received by one of the coils are phase shifted 90.degree. by a phase shifting circuit (50) and combined with the unphase shifted signals from the other coil by a combining circuit (52). The combined signals are amplified (54) and conveyed to electronic image processing circuitry (E) of a magnetic resonance scanner.

Abstract: A magnetic resonance imager includes a quadrature coil assembly (20) for transmitting radio frequency signals into and receiving magnetic resonance signal from an examination region. The quadrature coils assembly includes a first coil (22) and a second coil (24). A shunt path (32, 64, 74, 84, 94, 98, 100, 112, 114, 122) provides a current path by shunting at least a portion of one of the coils. A variable impedance (34, 66, 76, 86, 96, 110, 120) adjusts the amount of current flow through the shunt path and the current flow through the bypassed coil portion. More specifically, adjusting the impedance changes the magnetization vector generated by the coil assembly in a transmit mode and adjusts their relative isolation in a receive mode. The quadrature coils are mounted such that they are offset by about, but not quite, 90.degree.. The variable impedance is adjusted until the offset is brought precisely to 90.degree..

Abstract: Magnets (12) create a main magnetic field along a z-axis through an image region. A localized coil (D) is disposed in the image region at least to receive magnetic resonance signals from nuclei of the subject which have been induced to resonance. The localized coil includes an inner conductor (30), preferably a plate, which defines a current path extending along the z-axis. The inner conductor is mounted closely adjacent and parallel to a surface of the subject. An outer conductor (32), preferably also a plate, is mounted parallel to but further from the subject than the first conductor. A connecting member (34) interconnects a first end of the inner and outer conductors and is disposed perpendicular to the z-axis. A matching circuit (36) including capacitors (50) which define the resonant frequency of the coil are connected adjacent second ends of the inner and outer conductors.

Abstract: Magnet (12) creates a main magnetic field along a z-axis through an image region. A localized coil (D) is disposed in the image region at least to receive magnetic resonance signals from nuclei of the subject which have been induced to resonance. The localized coil includes an inner conductor (30), an outer conductor (32), and a dielectric material (52) therebetween. The outer conductor defines a gap (50) midway between its ends. One end of the inner conductor is connected with a gate of an FET transistor (66) and the outer conductor is connected with its source. The transistor source and drain are connected by a coaxial transmission cable (38) with a DC power supply (70) which provides a DC bias across the transistor source and drain. The cable also connects the transistor with a radio frequency receiver (40) to convey preamplified magnetic resonance signals thereto.

Abstract: The magnetic resonance signals in a magnetic resonance imaging apparatus are detected by a surface or localized coil assembly (D). To improve the field homogeneity and increase the signal-to-noise ratio when examining a region of interest deep within a subject, the surface coil assembly is configured with a first coil portion (22) and a second coil portion (24). The first coil portion is disposed along an exterior surface of the subject. The second coil portion is disposed parallel to the first coil portion and displaced outward a distance (44) from the first coil portion and the subject exterior surface. The first and second coil portions are electrically interconnected with an opposite current phase in a dipole pair such that the second current portion reduces the sensitivity of the first coil portion to magnetic resonance signals originating close to the surface of the subject.

Abstract: The thickness of a web is measured by passing the web through the gaps of a loop-gap resonator. Changes in web thickness alter the resonant frequency of the resonator which is detected by a control circuit. Three embodiments of the invention are described, and in one embodiment, the moisture content of the web is also measured.