Abstract: A voltage feed-through apparatus having reduced partial discharge having an electrical conductor and an electrical terminal connected thereto. A semi-conductor sleeve surrounds the conductor for reducing the electric field concentration at the metallic conductor surface and consequently reducing the partial discharge occurrences. An insulator sleeve encircles the semi-conductor sleeve. A metallic sleeve surrounds a portion of the terminal. Another insulator is connected to the metallic sleeve and surrounds a portion of the insulator sleeve forming a space therebetween. Another metallic sleeve spaced from the first metallic sleeve surrounds a portion of the other insulator.

Abstract: An oceanic wave measurement system wherein wave height is sensed by a barometer mounted on a buoy. The distance between the trough and crest of a wave is monitored by sequentially detecting positive and negative peaks of the output of the barometer and by combining (adding) each set of two successive half cycle peaks. The timing of this measurement is achieved by detecting the period of a half cycle of wave motion.

Abstract: Flame and temperature resistant polyimide foams are prepared by the reaction of an aromatic dianhydride, e.g., pyromellitic dianhydride, with an aromatic polyisocyanate, e.g., polymethylene polyphenylisocyanate (PAPI) in the presence of an inorganic acid and a lower molecular weight alcohol, e.g., dilute sulfuric acid or phosphoric acid and furfuryl alcohol.The exothermic reaction between the acid and the alcohol provides the heat necessary for the other reactants to polymerize without the application of any external heat. Such mixtures, therefore, are ideally suited for in situ foam formation, especially where the application of heat is not practical or possible.

Abstract: A method for separating biological cells characterized by the steps of suspending a mixed cell population in a body of aqueous polymer comprising a system consisting of phases for which said cells exhibit an affinity including at least one phase having droplets characterized by a first surface potential and at least one phase having droplets characterized by another surface potential, and subjecting said system to an electrostatic field established between a pair of electrodes, said field being of sufficient intensity for causing at least some of the droplets to migrate toward one of said electrodes with an attendant separation of the cells of said population.

Abstract: An over-under double-pass interferometer in which the beamsplitter area and thickness can be reduced to conform only with optical flatness considerations is achieved by offsetting the optical center line of one cat's-eye retroreflector relative to the optical center line of the other in order that one split beam be folded into a plane distinct from the other folded split beam. The beamsplitter is made transparent in one area for a first folded beam to be passed to a mirror for doubling back and is made totally reflective in another area for the second folded beam to be reflected to a mirror for doubling back. The two beams thus doubled back are combined in the central, beam-splitting area of the beamsplitter and passed to a detector. This makes the beamsplitter insensitive to minimum-thickness requirements and selection of material.

Abstract: A radiometer on an orbiting spacecraft derives high spatial resolution information from terrestrial and atmospheric regions. N elements or subapertures on the spacecraft transduce electromagnetic energy into electric signals.Many or all of the elements are simultaneously illuminated by electromagnetic energy radiated from the same region. Identical, parallel processing channels are responsive to the N elements. Each of the channels includes a variable gain amplifier responsive to the signal transduced by its corresponding array elements. The gain of each amplifier is controlled as a function of the output difference when the channel is connected periodically to each of a pair of Dicke noise sources, such as resistors maintained at predetermined temperatures.

Abstract: A method and apparatus for removing porphyrins from a fluid sample which are unrelated to the number of bacteria present in the sample and prior to combining the sample with luminol reagent to produce a light reaction. The method involves a pre-incubation of the sample with a dilute concentration of hydrogen peroxide which inactivates the interfering soluble porphyrins. Further, by delaying taking a light measurement for a predetermined time period after combining the hydrogen peroxide-treated water sample with a luminol reagent, the luminescence produced by the reaction of the luminol reagent with ions present in the solution, being short lived, will have died out so that only porphyrins within the bacteria which have been released by rupturing the cells with the sodium hydroxide in the luminol reagent, will be measured. The measurement thus obtained can then be related to the concentration of live and dead bacteria in the fluid sample.

Abstract: A method for forming a solar array strip including the steps of depositing solder pads on printed circuitry deposited on flexible substrate storing the resulting substrate on a drum, withdrawing the substrate from the drum and incrementally advancing it along a linear path, serially transporting solderless solar cells into engagement with the pads and thereafter heating the pads for thus attaching the cells to the printed circuitry, cleaning excess flux from the solar cells, encapsulating the cells in a protective coating and thereafter spirally winding the resulting array on a drum.

Abstract: Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

Abstract: A method wherein a quartz tube is charged with chunks of metallurgical grade silicon and/or a mixture of such chunks and high purity quartz sand, and impurities from a class including aluminum, boron, and the like, as well as certain transition metals including nickel, iron, manganese and the like. The tube is then evacuated and heated to a temperature within a range of 800.degree. C. to 1400.degree. C., whereupon a stream of gas comprising a reactant, such as silicon tetrafluoride, continuously is delivered at low pressures through the charge for causing a metathetical reaction of impurities of the silicon and the reactant to occur for forming a volatile halide and leaving a residue of silicon of an improved purity. Additionally, the reactant may include carbon monoxide gas, whereby impurites such as iron and nickel react therewith to form volatile carbonyls.

Abstract: A laser apparatus having a pump laser device for producing pump laser energy upon being excited. The pump laser device having a resonating cavity for oscillating and amplifying the pump laser energy. A source laser device is used for producing source laser energy upon being excited by the pump laser energy, the source laser device having a resonating cavity for oscillating and amplifying the source laser energy. The source laser's resonating cavity is coupled within a portion of the pump laser's resonating cavity.

Abstract: A method for analyzing the radiation sensitivity of an integrated circuit to determine the components, particularly tansistors, of greatest radiation sensitivity, including the application of a narrow radiation beam to portions of the circuit, as by applying the beam of a scanning electron microscope, so the radiation is applied to only one transistor at a time. The circuit is operated under normal bias conditions during the application of radiation in a dosage that is likely to cause malfunction of at least some transistors, while the circuit is monitored for failure of the irradiated transistor. If the irradiated transistor does not fail, then the other transistors are irradiated one at a time. When a radiation sensitive transistor is found, then the radiation beam is further narrowed and, using a fresh integrated circuit, a very narrow beam is applied to different parts of the transistor such as its junctions to locate the points of greatest sensitivity.

Abstract: A system for use in detecting earth crustal deformation using an RF interferometer technique for such purposes as earthquake predictive research and eventual operational predictions. A lunar based RF transmission or transmissions from earth orbiting satellites are received at two locations on Earth, and a precise time dependent phase measurement is made of the RF signal as received at the two locations to determine two or three spatial parameters of the antenna relative positions. The received data are precisely time tagged and land-line routed to a central station for real-time phase comparison and analysis. By monitoring the antenna relative positions over an extended period of months or years, crustal deformation of the earth can be detected.

Abstract: A sodium storage and injection system for delivering atomized liquid sodium to a chemical reactor employed in the production of solar grade silicon. The system is adapted to accommodate start-up, shut-down, normal and emergency operations and is characterized by a jacketed injection nozzle adapted to atomize liquefied sodium and a supply circuit connected to the nozzle for delivering thereto liquefied sodium comprising a plurality of replaceable sodium containment vessels, a pump interposed between the vessels and the nozzle, and a pressurizing circuit including a source of inert gas connected with the vessels for maintaining the sodium under pressure.

Abstract: A passive propellant acquisition and feed system is disclosed which will acquire and feed gas-free propellant in low or zero-g environments during orbital maneuvers which will also retain this propellant under high axially directed acceleration such as may be experienced during launch of a space vehicle and orbit-to-orbit transfers wherein the propellant system includes a dual compartment propellant tank with independent surface tension acquisition channels in each compartment to provide gas-free flow of pressurized liquid propellant from one compartment to the other in one direction only.

Abstract: A coal-rock interface detector employing a radioactive source and radiation sensor wherein the source and sensor are separately and independently suspended and positioned against a mine surface of hydraulic pistons which are biased from an air cushioned source of pressurized hydraulic fluid.

Abstract: An improved solar cell, and method of forming the same, characterized by a semiconductor silicon wafer of P-type material having diffused therein a shallow N-type region, a sintered silver contact affixed to the surface of the N-type region at the outer surface thereof formulated from silver powder blended with silver metaphosphate for establishing a zone of increased carrier concentration, and an aluminum or silver/aluminum alloy contact affixed to the P-type wafer at the outer surface thereof opposite the N-type region.

Abstract: An improved solar cell module for use in terrestrial environments, characterized by an internally reflective plate having a planar surface of incidence and an opposed textured surface, a plurality of uniformly spaced silicon solar cells having the active surfaces thereof bonded to portions of the textured surface, and a layer of diffusely reflective matter applied to the textured surface in surrounding relation with the solar cells for reflecting solar energy to strike the surface of incidence at such angles as to be internally re-reflected and caused to progress toward the active surfaces of the solar cells, whereby concentration of incident flux on the solar cell is achieved without increased module depth.

Abstract: A method for determining the characteristics and amount of microscopic contaminants lodged on a photographed surface. An image enhanced full-color photographic negative and print are taken of the contaminated surface. Three black-and-white prints are developed subsequently from red, green and blue separation filter overlays of the color negative. Both the color and three monochromatic prints are then scanned to extract in digital form a profile of any contaminant possibly existing on the surface. The resulting profiles are electronically analyzed and compared with data already stored relating to known contaminants.

Abstract: A segmented controller arm configured and dimensioned to form a miniature kinematic replica of a remotely related slave arm. The arm includes a plurality of joints for affording segments of the arm simultaneous angular displacement about a plurality of pairs of intersecting axes, a plurality of position sensing devices for providing electrical signals indicative of angular displacement imparted to corresponding segments of the controller shaft about the axes, and a control signal circuit for generating control signals to be transmitted to the slave arm. The arm is characterized by a plurality of yokes, each being supported for angular displacement about a pair of orthogonally related axes and counterbalanced against gravitation by a cantilevered mass affixed thereto whereby the controller arm may be released without introducing unwanted motion in the slave arm resulting from gravitation of segments of the master arm.