Abstract: Transistor device exhibiting negative resistance characteristics includes an enhancement mode insulated gate field effect transistor interacting with an integral bipolar transistor. The transistor device has a bulk region separated from a shallow substrate region by a pn-junction located in proximity to source and drain regions of the field effect transistor. The source region also serves as the emitter, the substrate region serves as the base, and the bulk region serves as the collector of the integral bipolar transistor wherein the substrate base is left floating. Normally, the collector of the bipolar transistor is connected to the gate of the field effect transistor, and a resistor of finite value is included in the gate circuit. Oscillator, astable multivibrator, gated oscillator, gated astable multivibrator, and bistable multivibrator circuits are illustratively constructed with the transistor device.

Abstract: Nonthermal and uncomplicated means and method of degassing a liquid are disclosed. The liquid degassing means includes a normally lower liquid vessel, a normally upper vapor vessel, evacuation means, and valved conduit means interconnecting with the liquid and vapor vessels and evacuation means. A trace gas manometer connecting with the liquid vessel is preferably included to measure the residual gas content at any time. The liquid degassing means is agitated to obtain good mixing of the liquid and vapor so that gas in the vapor is in equilibrium with gas dissolved in the liquid. The fluid is then transferred to the lower liquid and manometer vessels, and gas-laden vapor is isolated from the liquid and evacuated from the vapor vessel to remove a large amount of gas along with a relatively small amount of liquid in vapor form. The cycle is repeated until the necessary fluid purity is attained.

Abstract: Improved clamp means for mounting and firmly securing wires and the like comprises a conventional loop clamp or wire restraint and an anti-chafe support device of a nodal structure to prevent abrasion and chafing of the mounted wires. The anti-chafe support device can be made of a resilient material in strip form having raised nodes on one side and a longitudinal channel or groove on the other side to accommodate the loop clamp or wire restraint. A formed strip of suitable length is coiled and installed on the loop clamp or wire restraint so that the nodes are radially directed inwardly to provide a large gripping area for wires positioned against or between them. The nodes not only greatly increases wire retention force by providing a much greater gripping area but can also provide definite separation of wires positioned between spaced nodes.

Abstract: Lightning protection means for aircraft structural components includes thin, perforated, dielectric and metallic layers applied to the ordinarily lightning-accessible surfaces of composite structures. Where the outer metallic layer of the lightning protection means is formed from sprayed metal, ground connection means to the metallic layer preferably comprises a section of wire screen fused with the sprayed metal on the dielectric layer, a thin metal plate brazed to the wire screen, and a metal attachment connecting the metal plate to adjacent ground structure. Composite-to-metal or composite-to-composite structural joints are protected by making the entire bonded and bolted interface areas conductive for transfer of lightning current, or by isolating the bonded interface area to control the transfer path of the lightning current through the bolted interface area only.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, uniformly filling a normally upper portion of the tubing with a predetermined thickness layer of fine alumina particles, flattening and doubly folding and pressing the upper portion of the tubing at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed normally lower portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.

Abstract: A single gate field-effect transistor including a semi-insulating substrate for providing a one-sided device geometry, an isolating mesa formed from a layer of semi-conductor material provided on a substrate surface and which exhibits bulk negative resistance instabilities above a critical electric field strength, an extended gate structure provided in a gate region of the mesa, source and drain structures provided on the mesa at opposite sides of the gate structure, and electrical leads connected respectively to the gate, source and drain structures. The process for making the transistor, a multichannel (interdigitated structure) version, and a closed geometry (without mesa) version are also detailed.

Abstract: A decoder/analyzer test unit capable of rapidly identifying and isolating a failure or fault detected during a sequence of numerous discrete tests of a digital computer in an aircraft flight guidance system is disclosed. The test unit broadly comprises a means for comparing for coincidence of a signal representing a satisfactory result of a discrete test of a computer during a test sequence and another signal that initiated the particular discrete test, means for stopping the computer test sequencing when there is a lack of coincidence of the compared signals for any particular discrete test, and step counter means for counting and indicating the particular test that the computer is undergoing. Test points connecting with identified connections in the computer under test are provided on the test unit for troubleshooting purposes. The test unit can be operated in automatic, continuous and manual modes of operation.

Abstract: A cargo loading and unloading shutoff system is used to control transfer of loads between a cargo aircraft and a loading dock. Control logic means compares commands entered on a control console and the existing conditions in the aircraft and on the dock during a loading or unloading operation. On loading, the logic means shuts off the dock conveyor drive immediately when all loads are transferred to selected aircraft positions and then shuts off the aircract conveyor drive a predetermined period later. On unloading, the logic means shuts off both the aircraft and dock conveyor drives simultaneously when all loads are transferred to selected dock positions. The logic means also prevents energization of the aircraft and dock conveyor drives when the number of load positions selected in the aircraft is different from the number of load positions selected on the dock.

Abstract: A filter spectrograph unit for use in a micro-Raman spectrometer system or a remote sensing system is formed by combining an infinitely variable spectral line rejection filter (having appropriate entrance optics) functionally and operatively with a dispersing spectrograph. The line rejection filter is a modified form of a zero-dispersing double monochromator having an input light signal including laser light scattered from, for example, minute Raman-active particles. The modified double monochromator includes an acylindrical mirror positioned so that the laser line will exit through an aperture in the mirror and all other spectral lines will be reflected and reformed by the modified double monochromator into an output light signal containing all of the original spectral information, less the rejected laser line.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, filling the tubing with fine alumina particles, flattening and coiling and pressing an upper portion of the tubing at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed lower portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.

Abstract: A filter spectrograph unit for use in a micro-Raman spectrometer system or a remote sensing system is formed by combining an infinitely variable spectral line rejection filter (having appropriate entrance optics) functionally and operatively with a dispersing spectrograph. The line rejection filter is a modified form of a zero-dispersion double monochromator having an input light signal including laser light scattered from, for example, minute Raman-active particles. The modified double monochromator includes an acylindrical mirror positioned so that the laser line will exit through an aperture in the mirror and all other spectral lines will be reflected and reformed by the modified double monochromator into an output light signal containing all of the original spectral information, less the rejected laser line.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, placing a predetermined number of strands of stabilized zirconium oxide yarn of predetermined diameter longitudinally into one end of the tubing a predetermined distance therein, flattening and coiling and pressing the end portion of the tubing containing the yarn at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed (normally lower) portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.This is a division of application Ser. No. 376,527, filed July 5, 1973, now U.S. Pat. No. 3,803,816.

Abstract: High gain limited scan operation of phased array antennas is accomplished with microwave circuitry by appropriately coupling the array elements into sub-arrays and establishing a 90.degree. out of phase relationship between even and odd mode power at the aperture of each array element. Even and odd mode power from the feed circuit of each element is coupled to the feed circuit of each nearest adjacent element to form three element overlap subarrays in each plane of scan.

Abstract: Structural support assembly for use in arctic and subarctic (permafrost) areas or in any areas where the upper ground layer is subject to a severe annual freeze-thaw cycle, including the cooperative combination of a support structure and a heat pipe element installed in generally frozen soil. The heat pipe is of a suitably complementary configuration and/or disposition with respect to the support structure to provide appropriate stabilization of the surrounding frozen soil. In one embodiment, the heat pipe element is disposed externally of the support structure and, in another embodiment, it is disposed internally of (and integrally combined with) such structure. The external embodiment further includes one version employing a linear (straight) heat pipe element and another version employing an angular (helical) element.

Abstract: Process for producing microspheres comprises immersing a lower portion of a generally vertical, sol-gel feed tube having a lower microsphere formation needle in an alcohol drying column, feeding sol-gel at a predetermined rate into the upper end of the feed tube, and vibrating the feed tube in a generally horizontal direction at a predetermined amplitude and frequency to produce microspheres from the formation needle of a uniform and predetermined size. An electromagnetic transducer drive for vibrating the feed tube is used in one illustrative embodiment of apparatus for practicing the invention, and an electric motor offset drive is used in another illustrative embodiment of such apparatus. A feed tube having multiple microsphere formation needles at its lower end can be used for producing microspheres in quantity.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, filling the tubing with fine alumina particles, flattening and coiling and pressing an upper portion of the tubing at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed lower portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.