Abstract: A apparatus and method is described for the magnetron sputtering of a workpiece to deposit a thin metallic film. A rotating magnetic field is provided in the vicinity of the workpiece to produce higher yield from a given cathode target.

Abstract: A gelation shrinkable, polymer casting solution, that has been cast on the internal surface of a tubular support is gelled using pressure gelation by supporting the tubular support with one end higher than the other and pumping gelation liquid upwardly along the tube at a velocity in the range of the order of 10 to 100 cm/second and at a pressure of at least 10 kPa gauge at all points of contact between the gelation liquid and polymer casting solution. This achieves asymmetricity of the pore structure and ensures that the cast polymer solution is continuously in contact with the tubular support as a gelled membrane. If the tubular support is a porous, tubular support, then preferably the pressure gelation is continued until gelation liquid has passed through the cast polymer solution and the porous support removing solvent and any additives from the cast polymer solution.

Abstract: Disclosed is a high resolution frequency measuring system which uses a frequency counter for a coarse reading and a frequency to voltage converter for a vernier reading, which readings are combined. Two types of converters are disclosed. One embodiment comprises an input terminal for receiving an input signal frequency and a pulse shaper for converting the input signal to a first train of pulses. The pulses are applied to a delay means to produce a second train of pulses delayed with respect to the first train of pulses and the first and second trains of pulses are applied to first and second inputs of a phase detector, e.g. a flip-flop. In another embodiment, delayed and undelayed versions of the input signal are fed to separate pulse shapers and then to the inputs of the phase detector.

Abstract: Coal is treated to remove both pyritic and organic sulfur by contacting with an aqueous solution comprising cupric ions at temperatures of about 140.degree. C.-200.degree. C. under autogenic pressure, until substantial amounts of the sulfur are solubilized, separating the coal solids, and washing the solids with water to remove soluble forms of sulfur, iron and copper therefrom. The copper can be recovered and recycled as a cupric salt.

Abstract: The apparatus for analyzing the surface of a fibrous web, such as a paper or a textile, includes a prism structure in which one surface is placed in contact with the fibrous web under a predetermined pressure. A collimated beam of light is directed into the prism on the contact surface. The light reflected from the contact surface through the prism is directed to a detector. The detector senses the light reflected by the contact surface as well as the light diffracted at the contact surface to indicate the surface condition of the fibrous web.

Abstract: The laser-triggered high voltage rail gap switch includes two parallel electrodes in a high pressure environment of SF.sub.6 and Ar. A pulsed UV laser directs a coherent beam parallel to the electrodes to initiate multichannel breakdown in the gap between the electrodes. This breakdown is enhanced by including an organic additive such as fluorobenzene or tri-n-propylamine in the gas mixture.

Abstract: This invention provides a panel for use in doors or walls of vaults or strong rooms which is lighter in weight than conventional materials while providing comparable attack resistance. The panel consists of a layer of ceramic tiles adhesively secured to an energy-absorbing backing layer. Both faces of the panel are covered by sheet metal, and when the panel is used in constructing a door, the edges of the door also have a suitable metallic covering.

Abstract: The UV radiation triggered rail-gap switch applies a high voltage from a low impedance source to a low impedance load. The switch includes first and second parallel elongated electrodes spaced to form a uniform gap along their length. The first electrode is adapted to be connected to the high voltage source, while the second electrode is adapted to be connected to the low impedance load. When a voltage from the source is applied to the electrodes, one electrode will be positive relative to the other electrode. In addition, the cross-section of each of the electrodes is sufficiently smooth to prevent points of high field concentration between the electrode. This cross-section is defined by the field enhancement factor of each electrode which is preferably less than 1.5. The switch also includes an enclosure in which the electrodes are located and which contains a gas mixture for maintaining the breakdown threshold between the electrodes. A preferred gas mixture includes Ar, N.sub.2, and SF.sub.

Abstract: The hybrid inverter consists of thyristor switches with their related commutation circuit, paralleled by transistor switches. When the current magnitude is below a predetermined level, it is conducted by the transistor switches and when above the predetermined level, it is conducted by the thyristor switches. The commutation circuit includes a capacitor which need not be precharged to initiate commutation. Thus, the commutation circuit works only when a thyristor is conducting current thereby substantially reducing the number of commutations in an output cycle.

Abstract: A MODEM for a high frequency radio data link which substantially enhances the recovery of data transmitted via the link in the face of multipath distortion and fading. A serial digital input signal for transmission is split into odd bit and even bit data streams, having synchronous bit timing. Each pair of bits, referred to as a symbol, is phase shifted by .pi./4 which encodes its timing, for later clock recovery. The resulting signal is then twice differentially phase encoded which facilitates the recovery, when demodulated, of the original symbols overcoming the effect of Doppler shift and/or transmitted oscillator center frequency offset. The resulting signal then phase modulates a subcarrier signal having a frequency much higher than the symbol rate, and the phase modulated subcarrier is converted to a spread spectrum signal for transmission. This digital signal is provided to a high frequency analog transmitter for transmission with the signal spread over a particular HF channel, to a receive point.

Abstract: The reaction product of (i) an aromatic amide having the amine group of the amide attached to an aromatic ring, and (ii) a mono- or di-epoxide, has been found to be a good fortifier of epoxy resins. Epoxy resins have been found to attain increased strength and modulus (yet not brittle) by compounding:(a) a resin-forming polyepoxide,(b) an amine curing agent for (a), and(c) the above fortifier; and heat curing the mixture. Strengths as high as 130-150 MPa and modulus values to as high as 5000 MPa have been achieved yet with a ductile mode of fracture.

Abstract: The laser-surface coupler is used to uniformly irradiate a well defined surface area with a laser beam. The coupler includes a lower masking section and an upper section to form a cavity. The masking section has inner surfaces which are highly reflective and lustrous, and an aperture to define the surface area to be irradiated. The upper section has an opening to receive the laser beam into the cavity, and a highly reflective and diffuse inner surface to reflect and diffuse any radiation reflected to it from the irradiated surface. The coupler recycles any reflected radiation from the laser beam increasing the absorption coefficient and the irradiated surface is precisely defined by the masking section without loss of energy.

Abstract: A vacuum coating vessel is provided comprising a casing having a vacuum coating compartment separated from a vapor source compartment by a partition having vapor ports. A slidable shutter plate is provided on the vapor source compartment side of the partition. The shutter plate, in an open position, aligns vapor ports therein with the ones in the partition, and, in a closed, closes the vapor ports with `O`-ring seals. A mechanism is provided for moving the shutter plate away from and then towards the partition at the beginning and end respectively of each stroke to avoid scraping the `O`-rings and to ensure that the `O`-rings are kept as clean as possible. The vapor ports of the shutter plate and the partition are chamfered away from the vapor source compartment so that the `O`-ring sealing surfaces around the vapor ports in the partition are masked when the shutter plate is in the open position.

Abstract: It has been found possible to ferment the pentose D-xylose directly to ethanol with the selected yeast Pachysolen tannophilus. At least an initial aerobic stage is desirable. Improved yields have been obtained when the yeast cells are recycled continually at high cell densities. Fermentation of D-galactose and other hexoses along with D-xylose has been found possible with selected strains or mutants.

Abstract: A method and apparatus for rendering a high-voltage current-comparator capacitance bridge insensitive to frequency fluctuations when used for measuring inductance. A compensating current, proportional to twice the change in the current through the reference capacitor due to frequency fluctuations, is driven into the first comparator winding, through which the current from the reference capacitor passes, resulting in a current in that winding having frequency characteristics similar to those of the current passing through the second winding, which is connected to the inductance. This compensating current is derived from a reduced replica of the applied high-voltage or from the current through the reference capacitor.

Abstract: A ballistic helmet for use by bomb disposal personnel which includes a covering of soft ballistic nylon over a rigid polycarbonate shell. The shell is lined with semi-shock attenuating foam and is designed to cover the entire head. A transparent visor in the front of the helmet can easily be removed by the wearer and a blower assembly provides fresh air inside the helmet to eliminate fogging of the visor. The assembly incorporates an integral communication headset and microphone. Stability of the complete unit on the wearer's head is accomplished by a double-strap retention system.

Abstract: At a fiberoptic tap used for monitoring purposes, one fiber, having a certain mode volume is spliced to a second fiber having a relatively lower mode volume. Consequently, in passing from the first fiber to a second fiber, some light is radiated away from the splice. This radiated light is directed to a photodetector. The tap is particularly advantageous for transmitter power monitoring since the radiated optical power is superfluous to that light which is capable of transmission by the line fiber.

Abstract: The optical reflective filter is made from a photosensitive optical fiber having a cladding and a core including germanium. Refractive index perturbations are light induced in the fiber in the region of the guided light. The perturbations can be made to have a constant or a varying periodicity, or a series of constant periodicities. The filters are made from single mode or low order mode fibers having germanium doped silica or germania cores. The center frequency for reflective band or bands has a wavelength in the 400 nm to 550 nm range. The reflective band or bands in the filter can be shifted by stretching the filter.

Abstract: An insect trap for use in monitoring or suppressing flying insects, such as bark beetles. The trap comprises a plurality of conical members or funnels, and spacing members for spacing the funnels a predetermined distance when in use, and providing for nesting of the funnels for shipment or storage. Each of the funnels communicates with a funnel below and the lowermost funnel communicates with a collection container.

Abstract: A humane animal trap including a coil spring mounted on a frame and having its ends adapted to be spread apart when the trap is set. One end of the spring is held by a latch pivotally mounted for sideways movement on the frame. This latch is shaped so that, in order to hold the spring, it must be held by one end of a trigger which is mounted for vertical swinging movement on the frame. When the trigger is struck by an animal, it swings upwardly thus disengaging the latch and causing the one end of the spring to move downwardly towards the other end of the spring.