Abstract: The antenna feed includes a waveguide radiator with a conductive flange positioned about the waveguide near its radiating end. A dielectric element is positioned about the waveguide between the flange and the radiating end and establishes the dielectric surface impedance seen by the waveguide. The dielectric element may consist of one or more layers of dielectric material to form a composite dielectric. One of the layers may be an air gap adjacent to the flange. The size and position of the flange and dielectric element will control the radiation pattern of the beam from the feed.

Abstract: A significant enhancement of repellency toward the black fly (Simulium venustum Say, and Prosimulium hirtipes Fries) of N,N-diethyl-m-toluamide has been obtained by the addition, or conjunctive application of, vanillin, with the vanillin being present in minor proportion relative to the toluamide. A surprising decrease in black fly landings on the skin and bitings, was observed when the combination was used, compared to the toluamide alone.

Abstract: The inverter may be single phase with one inverter leg or N-phase with N inverter legs for connection across a DC source. Each leg includes a pair of series connected thyristors with a terminal between the thyristors for connection to a load. In addition, each thyristor has a diode connected in reverse polarity across it. A commutation circuit which includes an inductor in series with the inverter legs and a capacitor in parallel with the inductor and the inverter legs, provides a commutation pulse to turn off the thyristors in each leg. A further isolating inductor is connected at the DC power input to the inverter, and a reverse polarity feedback diode may be connected across it.

Abstract: Elongated members of reactive metals and alloys thereof, for example, uranium and alloys thereof, are cast from a crucible containing the molten metal blanketed with an inert gas and non-reactive prepared molten slag, directly into a mould protruding from the crucible. The cast metal is spray cooled with inert gas, which may be liquefied, as it emerges from an outlet end of the mould and is pulled, for example by rollers, into and possibly through an inert gas flushed container directly connected to the mould outlet end.

Abstract: A rare-gas hydrogen-halide laser is improved by including or adding a predetermined quantity of a hydrogen donor additive to its gas mixture. The closed-off operation lifetime of lasers such as XeCl, KrCl, or XeBr are tripled by adding up to 0.05% hydrogen to the laser gas mixture.

Abstract: A reverse osmosis method of concentrating fruit juices wherein a major portion of the fruit juice sugars are removed in a reverse osmosis first stage from the fruit juice at about room temperature and a pressure in the range 500 to 1500 psi, using porous cellulose acetate membrane material, while flavor compounds are removed in a reverse osmosis second stage from the separated water in liquid form therefrom at a temperature in the range 0.degree. C. to about room temperature and a pressure substantially in the range 50 to 1000 psi using asymmetric, porous, polymeric membrane material which is non-polar relative to the membrane material of the first stage as determined by .delta..sub.d of the solubility parameter of the membrane materials.

Abstract: This reference source provides a current which is of relatively high magnitude and which leads the voltage by substantially 90.degree.. It includes a reference capacitor which is highly stable and pure but of low capacitance, and a power capacitor which has a high capacitance. The capacitors are connected together at one end for coupling to a voltage source. A current comparator compares the currents flowing through the reference capacitor and the power capacitor, and provides a difference signal. A circuit generates a current in response to the difference signal and adds the generated current to the current through the power capacitor resulting in a current having a waveform and phase substantially identical to the reference capacitor current which leads the voltage source voltage by substantially 90.degree..

Abstract: The optoelectronic cross-point switch suitable for a broadband switching array includes a photodiode which converts an optical signal impinging upon it to an electronic signal and a biasing circuit for selectively reverse biasing the photodiode to render the photodiode responsive to the optical signal or forward biasing the photodiode to render the photodiode substantially non-responsive to an optical signal. The biasing circuit consists of positive and negative voltage sources and a controllable switch to connect the sources to the photodiode. A load circuit which is connected to the photodiode for developing the output signal may consist of a single resistor, a pair of series resistors, an operational amplifier with feedback or an rf transformer. The load circuit can also include an rf switching diode connected to the photodiode to improve isolation and to reduce the electrical power required to forward bias the photodiode.

Abstract: The conductivity cell consists of a first set of electrodes fixed rigidly to a second set of electrodes. Each set of electrodes has an insulating material support with an electrode well through it, and three spaced electrodes positioned sequentially within the well. In one embodiment, the support is a glass tube and the three electrodes are deposited on the inner surface of the glass tubes. In a further embodiment, the three electrodes are washer shaped conductive strips fixed within the electrode well and spaced by two washer shaped non-conductive strips also fixed within the electrode well. Each set of electrodes further includes a glass tubing fixed within the electrode well between each outer electrode and the outer end of the electrode well. In another embodiment, washer shaped electrodes are recessed in the wall of the electrode well such that the surface of the strips are flush with the electrode well surface.

Abstract: The sulfide surfaces of finely-divided impure iron sulfide-containing minerals such as pyritic ores or coals are rendered hydrophilic by the adsorption of conditioned, inorganic sulfide-oxidizing bacteria. This adsorption of conditioned bacteria occurs in a short time to render the surfaces hydrophilic and allows these altered sulfide particles to be separated from hydrophobic solids by flotation, oil-agglomeration or the like. This bioadsorption process has particular applicability to pyritic coal beneficiation.

Abstract: The loudspeaker telephone apparatus consists of a hybrid circuit which interconnects a telephone line and its line balance impedance with receive and transmit amplifiers. These amplifiers are connected to a bridge circuit, the arms of which are formed from two pairs of similar coil groups located in two multi-filar moving coil loudspeakers. The coil groups in one loudspeaker are connected in series aiding while the coil groups in the other loudspeaker are connected in series bucking. In one arrangement, the bridge circuit may be connected directly to the amplifier, the receive amplifier being connected across the pair of coils in each loudspeaker and the transmit amplifier being connected across the junction between the pair of coils in each loudspeaker. In another arrangement, a second hybrid circuit is used to connect the bridge to the amplifiers which are connected to the hybrid by its amplifier terminals.