Abstract: A method for fabricating indium variable thickness super conducting microbridges uses a single layer of electron resist and EBL to draw a mask which has a gap with a small amount of undercut. A thin layer of material is deposited at normal incidence to form the bridge and material deposited at a sufficiently large oblique angle forms the banks separately. Typical VTB's have bridges 1000 .ANG. thick and <0.4 .mu.m long with the banks 7 .mu.m thick and R.sub.n.sup..about. 0.1.OMEGA.. The method can also form other non-hysteretic weak links such as the SNS junction.

Abstract: A flexible coaxial connector assembly is used on buoyant cable antenna syms. It comprises a retainer assembly that has threads mating with a bellows assembly. Components that mate in a flexible manner are enclosed by the bellows. An electrical wire passes through these flexible mating components and terminates in a contact pin. The contact pin mates with an amplifier contact socket assembly.

Abstract: Optical sensing devices comprising dual chamber apparatii which use signal and reference light beams together with interferometric methods for detection of physical quantities of interest. The signal part of the chamber experiences the effects of a particular physical quantity to be measured which produces variations in the optical length of the light beam by movement of a mirror, thereby modulating that beam in proportion thereto. Concurrently, the reference beam, of equal pathlength, is passed through an adjacent chamber, isolated from such effects. The modulated signal beam and unmodulated reference beam are then combined to form a fringe pattern, the zero and first order fringes which are superimposed on apertures of an optical fibers, which carry the resultant light beams to a photodetectors for converting the optical signals to proportional electrical signals.

Abstract: A relatively solid mounting surface, which may be part of a leveling gimb supports a piezoelectric bearing mount which has the properties of an acoustic transducer. The transducer has electrodes thereon which are powered from multi-phase electrical sources causing the bearing mount, and a bearing jewel which is rigid therewith, to move so as to dither the jewel in a rotary or other preselected fashion, thereby reducing bearing friction. Bandwidth, level and phasing sequence of the power sources are adjustable permitting optimized average dynamic motion and corresponding increased readout accuracy.

Abstract: A stand-alone electronic simulator device for testing expendable bathythegraph (XBT) systems. The device is inserted into an XBT system in place of an expendable probe for purposes of checking the performance of the rest of the system with an active test signal. The test device simulates an operational XBT probe by switching a highly accurate and stable array of resistance values across its output. The switching rate is controlled by a stable internal time base such that the test pattern plotted on the strip chart recorder and transmitted to an external system will always look the same if the system is functioning properly. Temperature stability in the test device, essential because of the broad ambient temperature range which may be encountered in use, allows checks of the system for probe depth timing linearization in addition to temperature measurement.

Abstract: A valving device is provided in the inlet of a turbine engine to facilitate tarting in cold temperatures. The device or damper is positioned in the main compressor intake, is spring loaded in the open position, and is closed by hydraulic pressure during engine ignition. An increased fuel/air mixture and reduced velocity through the combustor result which enable starting of the engine at very cold temperatures.

Abstract: A thermo-electric valve for scuttling floating devices comprising, a cyliical sleeve affixed to and passing through a bulkhead separating a pressurized medium on one side from a lower pressure space on the other side, a piston moveably mounted within the sleeve bore and exposed to the pressurized medium having a portion thereof blocking the sleeve bore, an O-ring sealing the gap between the piston head and the sleeve bore, a fully compressed spring pressing against the piston, a rigid dielectric washer and a low power resistor holding the piston against the spring. In operation a low current is passed through the resistor, disintegrating it which releases the spring's stored energy. This actuates the valve by expelling the piston which allows the pressurized fluid or gas to enter the lower pressure space.

Abstract: A method for Ion implantation using multiple energy Be.sup.+ to produce p-type regions in n-In.sub.0.53 Ga.sub.0.47 As. A simple technique is used to develop capless annealing of InGaAs up to 700.degree. C. The ion implantation of silicon is then accomplished to create n.sup.+ layers in previously Be-implanted InGaAs epilayers. The active efficiency of 40% for 50 KeV Be implant has been found and efficiencies of 86% and 38% are found for the low and high energy Si implants respectively.

Abstract: This invention provides a means to increase the energy density of two eleochemical systems by using the by-product of each system as one of the necessary ingredients of the reactants of the other system. For example:(a) 2Li+H.sub.2 O.sub.2 .fwdarw.2LiOH(b) 2LiOH+3H.sub.2 O.sub.2 +2Al.fwdarw.2LiAlO.sub.2 .dwnarw.+4H.sub.2 Owhere the LiOH from (a) is used in (b) and the H.sub.2 O from (b) is used to fulfill the dilution requirements of (a).

Abstract: Olefin Methathesis is accomplished by combining olefins with acetylenes and ungsten salts such as tungsten hexachloride. This process simplifies olefin metathesis as acetylenes can be handled in the atmosphere, while ethylaluminum dichloride or related materials which have been used in the past instantaneously ignite when exposed to the atmosphere. Furthermore, the acetylenes bring about the reaction with much greater speed than when the initiator is a combination of a metal carbene and an acetylene. Besides, double bonds introduced in the polymer are highly stereoselective.

Abstract: Nylon 11 (.gamma.-phase) is electrically poled after it is crystallized f commercially available nylon 11 by rapidly crystallizing it from the molten state. The .gamma.-phase nylon 11 so obtained exhibits high piezoelectric properties when poled under different poling conditions at different temperatures. The electrically poled .gamma.-phase nylon 11 is used in a transducer.

Abstract: A broad bandwidth electro-mechanical transducer is shaped into a wedge of varying thickness, with a plurality of PZT elements or sheets embedded in an inactive polymer. The transducer is driven at frequencies corresponding to resonance of the thickness dimensions. The piezoelectric elements with different thicknesses are decoupled mechanically from one another using an inactive polymer of low Q so as to prevent interference.

Abstract: A frequency independent acoustic antenna has an acoustic filter plate located between a lens and sensor/transmitter. When used as a receiver this arrangement of components enables the lens to receive plane waves emanating from a source. This results in materially enhanced beam forming characteristics and performance. The arrangement is also suitable for use in the transmitting mode.

Abstract: A frequency independent log periodic acoustic device is utilized for the transmission or reception of underwater sound. A key element of the device is a particularly shaped plate or diaphragm, called a filter plate, made of stainless steel or other material having suitable acoustic properties. The filter plate on being placed in front of any plane wave receiving or transmitting transducer acts automatically to make the beamwidth of the diffraction pattern of the combined device constant, regardless of frequency. This is achieved by automatically making the effective aperture diameter of the filter plate-transducer combination a constant multiple of the acoustic wavelength of the sound in the underwater medium. When used in conjunction with a scannable transducer such as an acoustic lens and the retina device the filter plate produces a directional, scannable, substantially constant beamwidth diffraction pattern for radiation or reception of underwater acoustic signals.

Abstract: A Tactical Expendable Device (TED) adapted to be ejected into the water f a variety of launch platforms and to achieve and remain substantially stationary at a predetermined operating depth for a predetermined time interval or to sink at a predetermined rate for sensing acoustic signals and transmitting such signals to the launch platform through a long, small diameter connecting cable such as a fiber optic filament. The TED system comprises the TED cannister, a long connecting cable, deployment means on the launch platform including a launch tube with integral dereeler, a buffer and onboard signal processing/display equipment. The TED cannister further comprises a sensing element, a buffer, a power source and a dereeling device.

Abstract: An analog Gaussian convolver for performing high speed convolutions of arrary functions (e.g. image arrays) with masks or operators which uses two units of 2-dimensional Gaussians G(u,v) and the like. The output of the two units are subtracted to obtain difference of Gaussian operators (DOG), a very important parameter in computer vision. Input data in the form of a 2-dimensional digital array representing image pixels from the image array is converted into analog form and is then convolved with a 1-dimensional Gaussian operator in a first direction and the result is clocked into a tapped analog delay line. The outputs of the analog tapped delay line are also convolved with another (normally identical) 1-dimensional Gaussian operator in a direction normal to the first direction. The results so obtained represents the convolution of the image with a 2-dimensional Gaussian operator in a channel.

Abstract: A coherent array of Josephson oscillators is provided. Individual hysteresis-free Josephson junctions are longitudinally arranged in a line and have such a spacing as to substantially eliminate quasiparticle interactions. To provide a common frequency of operation, equal and opposite dc voltages are produced in adjacent pairs of the Josephson junctions by an arrangement of interlocking dc SQUID's (Superconductive Quantum Interference Device) connected to transversely extending biasing leads. Phase coherence for the array is provided by a rf current circulating in an inductive feedback path that loops between the ends of the array.

Abstract: A coherent array of Josephson oscillators is provided. Individual hysteresis-free Josephson junctions are longitudinally arranged in a gap of a central conductor in a line and have such a spacing as to substantially eliminate quasiparticle interactions. To provide a common frequency of operation, equal and opposite dc voltages are produced in adjacent pairs of the Josephson junctions by an arrangement of interlocking dc SQUID's (Superconductive Quantum Interference Device) connected to the longitudinal central conductor using microwave bias tees. Phase coherence for the array is provided by a rf current circulating in an inductive feedback path that loops between the ends of the array.

Abstract: An electrodynamic transducer has broadband operation and is suitable for erwater use. The transducer has a flexible rubber seal to assist in keeping the unit watertight. New features include a large flared air passage, a coil of wire that is rectangular in cross section and is routed through the center of a hollow centering shaft. In addition, a piston is machined out of beryllium copper with the piston attached to the shaft at the dome center and the skirt spider center. The transducer is designed to operate with the magnet having its outer pole piece in contact with the seawater.

Abstract: A system for detecting and identifying acoustic sound sources using a pluity of identical data acquisition modules spaced at preselected intervals along a line array. Two small diameter coaxial cables provide intermodular connections for power, timing control and sequential data transmission to a remote receiver. A control clock waveform leading edge simultaneously triggers sampling and holding of sensor data at each module of the array while the waveform trailing edge is delayed for a preselected interval at each module to provide squential data output.