Abstract: An acoustic array having polymer hydrophones is disclosed. The array compes a plastic roll, a plurality of polymer piezoelectric sensors affixed to the roll and electrodes that interconnect the sensors to utilization means such as those found for underwater detection systems or geophysical detection systems such as seismic detectors. The plastic roll has a pliant characteristic so as to readily assume a predetermined shape as well as, preferably, having a strong tendency to unravel and is of a relatively thin material. Similarly, the piezoelectric sensors have a pliant characteristic, are relatively thin, and are affixed to one of the surfaces of the plastic roll. Further, the electrodes have a pliant characteristic, are relatively thin, and are affixed to the same surface of the roll as the sensors.

Abstract: This invention comprises the use of diacetylene-containing polymers, e.g., olyamides containing reactive diacetylene groups that change their absorption in the visible spectrum with the application of strain as a strain sensing device in various organic matrix composites such as an epoxy laminated composite. The built in sensors in accordance with this invention will not affect the mechanical performance of the composite and will indicate strain without the need for extensive electronic equipment to measure the light pulse amplitude or phase before and after strain.

Abstract: A low power, wide-dynamic-range, signal compressor is suitable for operat from batteries. The compressor input is compatable with most sensors, resistive, capacitive or inductive and it is capable of compressing 150 db of input dynamic range into a 6 bit digital or 40 db analog signal. The output from the compressor is single valued and satisfactory for driving standard telemetry equipment.

Abstract: A corrosion-resistant coating which can be applied directly to a surface as self-priming topcoat comprising a polyurethane binder and a combination of pigments consisting essentially of an alkaline earth metal phosphosilicate, zinc salts of benzoic acids, and an alkaline earth metal phosphate such as zinc-barium phosphate. In addition, the coating contains up to about 35 parts by weight of a titanium dioxide pigment and up to about 3.0 parts by weight of an oil soluble surface active agent and up to about 50 parts by weight of at least one organic solvent.

Abstract: This invention relates to a process for preparing thermoplastic composites .e. laminates from a plurality of individual plies of thermoplastic resin prepregs. The prepregs are formed into composites under two substantially concentric vacuum chambers. High temperatures and low consolidating pressures are applied against the prepregs in an inner vacuum chamber while a lower vacuum is drawn from the rigid outer chamber to remove the volatiles and consolidate the prepregs.

Abstract: A system and method of indirect underwater acoustic ocean surveillance is sclosed requiring at least two sonar platforms, usually ships, travelling some distance apart. At least one of the platforms transmits sonar pulses, portions of which are scattered off the ocean floor to at least one companion sonar receiver platform. The receiver platform is provided with means to analyze the received scattered sonic pulses to determine if a submerged object such as a submarine is obstructing a portion of the pulse, thus casting an acoustic shadow. With accurate positioning information supplied by a navigation information system such as the NAVSTAR GLOBAL POSITIONING SYSTEM (GPS), and by combining pulse measurements over several positions the system will be able to locate, identify, and track the obstructing object by analyzing these acoustic shadows or silhouettes. Geometric silhouette reconstruction techniques and other mathematical techniques may be employed to construct an image of the submerged object.

Abstract: An optically controlled active impedance element particularly suited to se as a tuneable inductive element for a microwave oscillator is disclosed. The optically controlled active inductive element is comprised of a circuit arrangement, preferably consisting of MESFET devices which exhibit a composite inductive characteristics, and whose inductance may be determined and controlled by direct illumination impinging on the MESFETs. The optically controlled active inductive element lends itself to being adapted to monolithic microwave integrated circuit (MMIC) applications and may find use in a wide variety of microwave circuits. Also disclosed, is an embodiment which uses the optical controlled active impedance element, in a prescribed manner, to serve as a tuneable capacitor for use in various microwave circuits.

Abstract: A lift enhancing device for an inextensible, membraneous wing is disclosed. he device comprises the "forced" reattachment of a section of the trailing edge back to the trailing edge so that a warp is introduced therein. The section is reattached with flexible tape to allow oscillation of the section, and increased lift from the wing, at prescribed airspeeds.

Abstract: A launch-chute extender is disclosed that snap-fits onto the end of a buoy ontainer in an aircraft that carries stores internally. This extender, by adding its tubular configuration to the end of the buoy container, provides guiding clearance to selected stores to enable them to exit from the underside of the aircraft without becoming jammed.

Abstract: An underwater transducer comprises a piezoceramic transduction layer and a etal substrate with a thin film of viscous fluid between them. The viscous film allows the transduction layer and substrate to expand and contract relative to each other when the laminate bends under increasing hydrostatic pressure as the transducer descends in a body of water. At sonic frequencies, however, the viscous film provides effectively a rigid bond between the transduction layer and the substrate so that they vibrate in unison. The invention reduces hydrostatic compressive loading on the transduction layer and thereby improves performance in deep water applications. A ring on the substrate surrounds and is engaged by the edge of the transduction layer as hydrostatic pressure increases in order to apply enough compressive stress to the transduction layer to prevent peaks in dynamic loading from exceeding the tensile limits of the transduction layer.

Abstract: An optical transmitter particularly suited for high frequency applications s disclosed. The optical transmitter successfully operates in harsh environments such as those found in avionic applications. The optical transmitter employs an LED as a light source which cooperates with an active bandpass amplifier to provide a relatively wide bandwidth from about 250 MHz to about at least 1.35 GHz. The bandpass amplifier is selected to have a slope characteristic which is complementary to a roll-off characteristic of the LED and compensates for the high frequency loss of the LED. The slope characteristic of the bandpass amplifier predominates at the high frequencies of the response of the optical transmitter, whereas the frequency response of the LED dominates at the lower frequencies of the response.

Abstract: A corrosion-resistant coating which can be applied directly to a surface as self-priming topcoat comprising an epoxy resin binder and a combination of pigments consisting essentially of an alkaline earth metal phosphosilicate, zinc salts of benzoic acids, and an alkaline earth metal phosphate such as zinc-barium phosphate. In addition, the coating contains up to about 35 parts by weight of a titanium dioxide pigment, up to about 3.0 parts by weight of an oil soluble surface active agent and up to about 50 parts by weight of at least one organic solvent.

Abstract: An optically controlled active impedance element particularly suited to se as a tuneable inductive element for a microwave oscillator is disclosed. The optically controlled active inductive element is comprised of a circuit arrangement, preferably consisting of MESFET devices which exhibit a composite inductive characteristics, and whose inductance may be determined and controlled by direct illumination impinging on the MESFETs. The optically controlled active inductive element lends itself to being adapted to monolithic microwave integrated circuit (MMIC) applications and may find use in a wide variety of microwave circuits. Also disclosed, is an embodiment which used the optical controlled active impedance element, in a prescribed manner, to serve as a tuneable capacitor for use in various microwave circuits.

Abstract: A cable-pack winding and payout system is disclosed that will provide a tue-free cable payout from a wound cable pack, such as are found in ocean-deployed buoy packages. Dual feed spools are arranged so that the two halves of the cable can be simultaneously wound onto a single main spool. At time of payout, the pack is inertly payed out from the center or both ends and the payed-out cable has no curls or twists therein.

Abstract: Helmet visor support apparatus is provided which can move the visor between raised and a lowered position by the operation of one hand. The apparatus comprises a visor support arm pivotally attached to the helmet at a pivot point for moving the visor between the raised and lowered positions. A positioning means is attached to the helmet at the pivot point and has at least two bores corresponding to the raised and lowered visor positions. A locking pin retractably engages either one of the bores in the positioning means to lock the visor support arm in position. A spring coiled around the locking pin normally biases the locking pin in engagement with one of the bores. A manually activatable retracting means is attached to the locking pin for retracting the locking pin from the one of the bores upon being manually activated, thereby allowing the visor support arm to pivot.

Abstract: A goggles emergency release apparatus is disclosed wherein an actuator, ptioned adjacent the goggles latching mechanism, drives a wedge into the mechanism to push a release pin into the open position and push the goggles away from the helmet. The actuator receives its initiation power when the ejection seat movement closes a microswitch.

Abstract: Apparatus is provided for modulating the phase of a coherent light beam pagating through the core of a single-mode waveguide. A light-absorbing element is connected to a portion of the cladding of the waveguide such that there is a thermal interface therebetween. A means is provided for launching light into the portion of the cladding of the waveguide having the light-absorbing element connected thereto. The light-absorbing element absorbs the light and produces heat in proportion to the light's energy. The heat thus produced is transferred to the waveguide, changing its optical path length and varying the phase of the light propagating therethrough. The intensity of the light launched into the cladding is variable and is controlled by a power supply. The modulator may be used in an interferometer in which a signal is directed to the power supply to control the light intensity for various purposes.

Abstract: An aircraft fire-fighting training apparatus is disclosed that allows firghters to train on a mock-up that simulates a real-life aircraft fire but yet is controllable and environmentally safe. A fuel source feeds liquid propane through several discrete shut-off valves to sets of primary and secondary nozzles where it is ignited. A deflector shield placed adjacent the primary nozzles forces the flames into a channel adjacent the mock-up, causing a rolling flame to engulf all of the fuselage of the mock-up. Secodary nozzles provide flame to simulated landing gear attached to the mock-up wings.

Abstract: A method is provided for detecting and localizing acoustic sources. Acous signals are transmitted by a sonobuoy and return signals are received. Electrical signals, corresponding to the received return signals, are multiplexed and transmitted. The transmitted signals are received by a receiver which is separated from the transmitter. The receiver applies the received signal to a demultiplexer which is separate from the the receiver. The demultiplexer demultiplexes the applied signals to provide electrical signals to the cardioid beamformer representative of the sonar return signals.

Abstract: A supersonic aircraft or missile broad bandwidth antenna is provided. This antenna is constructed into a cavity created in the fuselage or wing of the aircraft and covered with a radome for flush mounting. The cavity comprises side walls and a bottom constructed of electrically conductive materials which are caused to be electrically excited by an antenna element located within the cavity. This antenna element, which is capable of broad bandwidth operation, is either passively or actively tuned. Active tuning is carried out by a logic converter circuit connected to the antenna from a communications transceiver.