Abstract: An arrangement for sensing the fluid separation along a surface employs a thermally insulating element having a continuous surface blending into and forming a part of the fluid flow surface. A heating conductor is mounted on the element at the element surface. Two thermal sensors each has a conductor, the sensor conductors being mounted at the element surface on opposite sides of the heating conductor. In operation a fluid flow along the surface in a direction successively through the conductors carries heat in its wake to the downstream conductor where it is sensed. The upstream sensor also senses the temperature of the fluid flow before it reaches the heating conductor. When the fluid flow separates from the surface at the area of the heating and sensing conductors, a sudden decrease in the temperature of the downstream sensor conductor and concomitant increase in the temperature of the upstream sensor conductor is an indication of the separation.

Abstract: A drift compensated and intensity averaged extensometer for measuring the diameter or other properties of a substantially cylindrical sample based upon the shadow of the sample. A beam of laser light is shaped to provide a beam with a uniform intensity along an axis normal to the sample. After passing the sample, the portion of the beam not striking said sample is divided by a beam splitter into a reference signal and a measurement signal. Both of these beams are then chopped by a light chopper to fall upon two photodiode detectors. The resulting AC currents are rectified and then divided into one another, with the final output being proportional to the size of the sample shadow.

Abstract: An apparatus for performing electrophoresis and a multiple-sample applicator for use therewith. Electrophoresis is a physical process in which electrically charged molecules and colloidal particles, upon the application of a DC current, migrate along a gel or a membrane that is wetted with an electrolyte. If a membrane is used, its middle section is kept in tension horizontally above an electrolyte tank, while the ends of the membrane hang down into the electrolyte. If a gel is used, it is held in a tray which is placed on a cooling plate, and wicks make contact with the electrolyte. The tank has unique protected electrodes for conducting the DC current.A multiple-sample applicator is provided which coacts with a novel tank cover to permit an operator either to depress a single button, thus causing multiple samples to be deposited on the gel or on the membrane simultaneously, or to depress one or more sample applicators separately by means of a separate button for each applicator.

Abstract: An apparatus for dispensing fluid according to a time schedule is disclosed. Fluid automatically flows to individual dispensing units at predetermined times from a fluid supply and is available only for a predetermined interval of time after which an automatic control causes the fluid to drain from the individual dispensing units. Fluid deprivation continues until the beginning of a new cycle when the fluid is once again automatically made available at the individual dispensing units.

Abstract: A superconducting microbridge is provided for use in superconducting quantum interference devices wherein a pair of spaced layers of superconductive material are connected by a weak link bridge to establish an electrical junction. The superconductive layers and bridge are coated with a semiconductor material shunting the bridge at room temperatures to prevent the destruction of the device by minute electrical currents while the coating acts as a dielectric permitting normal electrical behavior of the microbridge at cryogenic temperatures.

Abstract: An apparatus for measuring a sorbate dispersed or dissolved in a fluid stream and comprising an oscillator for generating a first alternating-current signal, an acoustic transmission line for disposition in the fluid stream and including an elongated body having a surface capable of sorbing an amount of the sorbate to be measured representative of the concentration thereof in the fluid stream, the body being capable of propagating acoustic energy along its length from one end portion to another end portion, the propagated acoustic energy being damped in amplitude and shifted in phase such that the change in amplitude or phase is proportional to the amount of sorbate sorbed by the surface, a first transducer for converting the alternating current signal to acoustic energy and for applying the acoustic energy to the one end portion, a second transducer for converting the acoustic energy propagated to the other end portion to a corresponding electrical signal, and a comparator for comparing the electrical signal

Abstract: An X-band traveling wave maser of the folded-comb type is provided with two figure-eight coils for gain and bandwidth control. One figure-eight coil covers the full length of the comb structure for bandwidth adjustment of an external magnetic field. The other figure-eight coil covers a central half of the comb structure for independent gain adjustment of the external magnetic field. The half of each figure-eight coil at the turn around end of the comb structure is oriented to aid the external magnetic field, and the half of each figure-eight coil at the input-output end of the comb structure is oriented to buck the external magnetic field. The maser is pumped in the push-push mode with two different frequencies.

Abstract: A Schottky barrier solar cell is disclosed, consisting of a layer of wide band gap semiconductor material such as AlGaAs on which a very thin film of semi-transparent metal is deposited to form a Schottky barrier. The layer of the wide band gap semiconductor material is on top of a layer of narrower band gap semiconductor material, to which one of the cell's contacts may be attached directly or through a substrate. The cell's other contact is a grid structure which is deposited on the thin metal film.

Abstract: An interferometer having servo means for automatically adjusting the angular tilt of a reflecting surface in one of two paths to maintain the exit beams from the two paths parallel to each other. Three detectors at the output of the interferometer are disposed on mutually perpendicular axes which define a plane normal to the nominal exit beam axis. One detector at the origin of the axes is used as a reference for separate phase-difference comparison with the outputs of the other two detectors on the X and Y axes to develop servo error signals.

Abstract: Apparatus for transferring gas from a first container to a second container of higher pressure comprising a free-piston compressor having a driving piston and cylinder, a smaller diameter driven piston and cylinder, and a rod member connecting the driving and driven pistons for mutual reciprocation in their respective cylinders. A conduit may be provided for supplying gas to the driven cylinder from the first container. Also provided is control apparatus for intermittently introducing gas to the driving piston, from the first container, to compress gas by the driven piston for transfer to the second higher pressure container.

Abstract: A wet oxidation process for oxidizing waste materials comprising dissolving a ruthenium salt in a reactant feed stream containing the waste materials, introducing the feed stream into a reactor, heating the reactor contents to an elevated temperature to effect deposition of a catalytic surface of ruthenium black on the interior walls of the reactor and maintaining the feed stream in the reactor for a period of time sufficient to effect at least partial oxidation of the waste materials.

Abstract: An overload protection system for a power inverter utilizes a first circuit for monitoring current to the load from the power inverter to detect an overload and a control circuit to shut off the power inverter when an overload condition is detected. At the same time a monitoring current inverter is turned on to deliver current to the load at a very low power level. A second circuit monitors current to the load from the monitoring current inverter to hold the power inverter off through the control circuit unitl the overload condition is cleared so that the control circuit may be deactivated in order for the power inverter to be restored after the monitoring current inverter is turned off completely.

Abstract: A suspended mass is shaped by melting all or a selected portion of the mass and applying acoustic energy in varying amounts to different portions of the mass. In one technique for forming an optical waveguide slug, a mass of oval section is suspended and only a portion along the middle of the cross-section is heated to a largely fluid consistency. Acoustic energy is applied to opposite edges of the oval mass to press the unheated opposite edge portions together so as to form bulges at the middle of the mass. In another technique for forming a ribbon of silicon for constructing solar cells, a cylindrical thread of silicon is drawn from a molten mass of silicon, and acoustic energy is applied to opposite sides of the molten thread to flatten it into a ribbon.

Abstract: A method of determining vegetation height and water content of vegetation from the intensity and state of elliptical polarization of a reflected train of microwaves. The method comprises the steps of reflecting a circularly polarized train of microwaves from vegetation at a predetermined angle of incidence, detecting the reflected train of microwaves, determining the ratio of the intensities of the electric field vector components, measuring the phase difference of the components, and computing the refractive index and thickness of the layer of vegetation from a formula, wherein the refractive index is given essentially by the water content of the vegetation.

Abstract: A solar heat collection system is provided by utilizing a line-focusing device that is effectively a cylindrically curved concentrator within a protected environment formed by a transparent inflatable casing. A target, such as a fluid or gas carrying conduit is positioned within or near the casing containing the concentrator, at the line focus of the concentrator. The casing can be inflated at the site of use by a low pressure air supply to form a unitary light-weight structure. When deflated, the collector, including casing, concentrator and target, is readily transportable.A system constructed from a plurality of such line-focusing devices can be used either at ground level or on rooftops. A system may advantageously utilize a plurality of parallel aligned heat absorbing rigid conduits as targets, each conduit supporting an inflatable concentrator and casing.

Abstract: An improved X-ray photoelectron spectrometer is disclosed, which includes circuit means to determine the surface potential of a sample, e.g., an insulator. The circuit means comprise an electron gun, whose potential is modulated at a preselected frequency above and below a selected potential with respect to the spectrometer common potential, e.g., ground. The beam of electrons is directed to the sample surface. The sample's surface potential is offset by an offset power supply with respect to the spectrometer common potential until the AC current which flows through the sample reaches a peak amplitude. A lock-in amplifier is included to measure the AC current in phase with the modulating frequency.

Abstract: Disclosed is a malfunction detection system for detecting malfunctions in electrical signal processing circuits. In a particular embodiment shown, malfunctions of a hearing aid in the form of frequency distortion and/or inadequate amplification by the hearing aid amplifier, as well as weakening of the hearing aid power supply are detectable. A test signal is generated and a timed switching circuit periodically applies the test signal to the input of the hearing aid amplifier in place of the input signal from the microphone. The resulting amplifier output is compared with the input test signal used as a reference signal. The hearing aid battery voltage is also periodically compared to a reference voltage. Deviations from the references beyond preset limits cause a warning system to operate. In the method of the invention, the input to a circuit to be tested is periodically interrupted and, for a fixed test time interval, a test signal is applied to the circuit to be tested.

Abstract: The method of refining, or growing, bulk single crystals in which the base material is suspended, positioned, and shaped as a containerless melt by wetting forces in an environment substantially free of gravity.

Abstract: The device concerns the circulation of cabin air through canisters which absorb and adsorb carbon dioxide, together with excess moisture, and return the scrubbed air to the cabin for recirculation. A coating on an inert substrate in granular form absorbs and adsorbs the impurities at standard temperatures and pressures, but desorbs such impurities at low pressures (vacuum) and standard temperatures. This fact is exploited by making the device in a stack of cells consisting of layers or cells which are isolated from one another flow-wise and are connected to separate manifolds and valving systems into two separate subsets. A first subset may be connected for the flow of breathable air therethrough until the polyethyleneimine of its cells is saturated with CO.sub.2 and H.sub.2 O. During the same period the second subset of cells is manifolded to a vacuum source.

Abstract: A tracking three-dimensional solar energy concentrator is provided by a stretched aluminized polymeric membrane supported by a hoop, the polymeric membrane being formed to a desired curvature by differential loading. The loading on the polymeric membrane determines its curvature. The loading can be varied by utilizing a plastic membrane that has a non-uniform radial distribution of thickness with uniform differential pressure or by applying a non-uniform differential pressure on a membrane having uniform thickness. Reflector membranes having a non-uniform radial distribution of thickness can be obtained by selective spraying of a dissolved plastic such as Krylon on the underside of the aluminized membrane. A non-uniform differential pressure is obtained by using a uniform differential pressure in combination with localized electrostatic or magnetic pressure.