Abstract: An apparatus for forming composite, fiber/resin components with fibrous, resin-impregnated tape is disclosed. The apparatus employs a gantry for positioning a tape dispensing head assembly over a mold structure, which defines a mold surface of planar or contoured configuration. A control system is employed having sensing devices for generating signals indicative of relative positions of components of the apparatus in several axes of permissible movement, and tape application is effected by means of major and secondary command inputs to appropriate servomotor devices. Primary and initial movement is controlled in accordance with a sequence command program in cooperation with a resident program in a digital computer, and a second, adaptive control system is alternatively employed for enabling the tape dispensing head to follow vertical contours of the mold surface during X-Y movement across the surface.

Abstract: A radiographic imaging system (10) includes first and second housing segments (10a, 10b) with the second housing segment (11b) having a low-light-sensitivity television camera (13) mounted therein. The first housing segment (11a) has a radioluminescent screen structure (20) fitted within an opening (16). A workpiece (24) is positioned adjacent the radioluminescent screen (20) and between the screen and a source of radiation (25a, 25b). The screen structure includes means for producing a scintillation shadowgraph pattern in response to impingement on the screen of radiation directed through the object. The camera (13) has its optical input section directed toward the radioluminescent screen for receiving the scintillation shadowgraph pattern and has a target means for forming charge patterns corresponding to the scintillation patterns produced on the radioluminescent screen and scanning means for scanning the target means to generate an optical signal corresponding to the charge pattern formed on the target.

Abstract: In accordance with the invention, a composition of matter is provided for forming a coating for protecting carbonaceous substrates from degradation at elevated temperatures. The composition of matter is a mixture of particulate silicon, silicon carbide and alumina. The mixture contains between about 40% and 50% silicon by weight of the total composition, between about 30% and 50% silicon carbide by weight of the total composition and between about 20% and 30% alumina by weight of the total composition. A method is provided for forming a primary protective coating on carbonaceous substrates utilizing the aforesaid mixture. An enhancement coating is provided for sealing the primary coating in applications where the substrate will be subjected to elevated temperatures and temperature cycling.

Abstract: In a system for generating thermal (14 MeV) neutrons containing an ionic accelerator, a novel thermal neutron collimator for producing a beam of collimated thermal neutrons is disclosed. The apparatus includes a substantially hollow collimator tube (10) having a closed, neutron permaeable inlet portion (20) communicating with a source of thermal neutrons (12) and an open outlet portion (22) disposed downstream of the inlet portion at the opposite end of the tube. The collimator walls (14,16,18) diverge outwardly toward the outlet portion of the tube and are formed of three radial layers comprising an outer layer of thermal neutron absorbing material (26) for absorbing off-axis thermal neutrons, an intermediate layer of lead (24) for absorbing X-rays and gamma rays and an inside layer of aluminum (23) for structural support.

Abstract: An apparatus is disclosed for forming concave tape wrapped composite structures. The apparatus utilizes a mold having a cylindrical concave surface with a mounting plate mounted for rotation at each end thereof about a point on a longitudinal axis of the concave surface. A longitudinal shaft is mounted to each mounting plate a selected distance from the longitudinal axis and extends parallel thereto. A tape dispenser carriage is mounted to the longitudinal shaft and is movable along the length thereof. A radial shaft is mounted through the tape dispenser carriage such that the longitudinal axis of the radial shaft passes through the longitudinal axis of the concave surface and along a radius of the concave surface.

Abstract: A composite material manufacturing process and resulting structure is provided to include high strength material whiskers (20) having a characteristic orientation when placed in an electromagnetic field (22). In one embodiment, whiskers (20) are disposed between lamina (10 and 15) and oriented generally perpendicular to the fiber layers (14 and 18). The whisker (20) orientation is maintained during a curing cycle for the respective matrices (12 and 16) wherein the matrix viscosity allows the whiskers (20) to orient in response to the applied electromagnetic field (22). The whiskers (20) retain their orientation in the resulting laminate to provide improved structural integrity for the laminate.

Abstract: A multiplexed multiplex bus includes a bus controller for controlling the traffic on a multiplex bus network. A plurality of extended buses are stubbed off of one stub on the main bus and are buffered by a series of driver/receivers. Control remote terminals enable one of the extended buses under control of the bus controller for subsequent communication with the main bus. The bus controller can address the control remote terminal to activate one of the extended buses and then address the remote terminals thereon. The remote terminals on all of the extended buses have identical addresses and, as such, are not simultaneously connected to the main bus at any given time.

Abstract: Apparatus for rapidly erasing and rebiasing a thermoptic thin film in the near and medium infrared. A thermal insulating material (56) is disposed adjacent a thermoptic vanadium oxide thin film (50). The insulating layer has high transmittance in the 3-5 or 8-12 micrometer spectral bands. A layer of resistive semiconductor material (54) having high transmittance in the 3-5 or 8-12 micrometer band is disposed between the layer of insulating material and the vanadium oxide thin film. A multilayer dielectric thin film stack is superposed adjacent the vanadium oxide thin film, or is disposed in two parts adjacent the upper and lower surfaces of the thermoptic thin film.

Abstract: A small caliber guided projectile (20) includes a maneuvering unit (22) having a forward opening inlet (36) which provides diffused air to a flow control mechanism (70) prior to exhausting such air through diametrically opposed exhaust nozzles (74, 76). The flow control mechanism (70) includes a primary flow passageway (78) and an upper orifice switching device (100) for controlling bypass flow to one of the exhaust nozzles (76). An orifice switching device (120) controls bypass flow to the other exhaust nozzle (74). In one embodiment, a small, rearward facing step or other means of vortex generation, such as boundary layer energization, is located upstream of the discharge of the flow through switching devices into the nozzles. When the switching devices are closed, flow over the rearwardly facing steps generates a small vortex which enhances flow attachment as a result of the Coanda effect and increases flow through the nozzle.

Abstract: A circuit for providing controlled switching of power applied to a load is adapted for actuating and deactivating a power switching circuit in response to a command signal. The circuit employs a switching circuit having a time delay section operable to terminate application of power immediately upon the cessation of a control signal and to conduct current after a predetermined delay interval after receipt of a command signal. The circuit is adapted for use with pyrotechnic ignition systems in which it is desired to quickly discharge capacitive elements connected to a load for prevention of undesired and possibly hazardous build-up of heat in a resistive ignition element.

Abstract: A relatively high speed memory system is provided utilizing relatively low speed electronic memory devices such as NOS integrated circuits. The memory system is organized as a planar array with rows and columns of word positions and includes an address generator for generating sequences of N address bits to access sequences of N words of data where N is greater than 1 along any selected substantially straight path in any direction along the memory array with each address generating having a set of most significant bits and a set of least significant bits. Each electronic memory device includes an address decoder which is responsive to a first plurality of address bits for selecting a memory element within the memory device and an enable circuit for enabling the memory device. The logic circuit coupling the address generator to the electronic memory devices selectively enables at least one memory device during each memory access and no one memory device is selected more than once per N memory access.

Abstract: A material and process for preparing corrosion resistant reflective material. The process in the preferred embodiment comprises abrading a metal substrate, anodizing the metal substrate, depositing a thin film of substantially pure metal on the anodized substrate, and covering the reflective metal with a protective organic coating. The material produced is a metallic substrate having an anodized layer with a relatively thin film of reflective metal covered by a protective organic coating.

Abstract: Stimulated emission at the approximate wave length of 4.5 microns, 2.25 microns and 1.6 microns is obtained from pumping on an excited energy level. The phenomenon of photon avalanching is utilized to create a population inversion within three lower level states that have a substantially equal energy spacing to provide resonance between neighboring ions. This resonance feeds the photon avalanching process when pump having sufficient power in excess of the critical pump power irradiates a LaCl.sub.3 :Pr.sup.+3 crystal at an excited energy level to maintain a population inversion in an optical cavity.

Abstract: A propulsion system for vertical take off and landing aircraft includes a forward compressor fan (40) and an aft compressor fan (42) downstream of the forward fan and in series flow communication with the forward fan. The forward and aft fans are positioned in a central duct (26). A gas turbine engine (44) is in series flow with the forward and aft fans for driving the fans. The forward fan, aft fan and turbine engine are interconnected by a common shaft (50). A forward diverter structure (100) is positioned downstream of the forward fan and is movable between a first position for diverting exhaust from the forward fan downwardly relative to the longitudinal axis of the aircraft while simultaneously permitting the introduction of air behind the forward diverter structure but ahead of the aft fan and a second position wherein the exhaust from the forward fan is channeled through the aft fan and turbine.

Abstract: A process for sealing silicon carbide primary coatings of carbonaceous substrates comprising impregnation and curing with tetraethyl orthosilicate, application of a sealant mixture followed by curing, application of a liquid sealant followed by curing, high temperature heat treatment, and repetitive of the application of the materials described above.

Abstract: The specification discloses a method and apparatus for stabilizing images in the reference frame of a forward or down looking infrared receiver moving relative to the scene. An infrared modulator (14) is disposed in the image plane of the receiver for imaging infrared energy from the scene. The modulator (14), normally nonreflecting of infrared energy incident thereon, is capable of having reflective spots written on selected locations thereon to reflect infrared energy incident at those locations. Detectors (24) positioned to detect infrared energy reflected from the modulator provide an output signal representing the radiance values of the sampled scene element. A microprocessor (30) is connected to the detector, responsive to the detected output signal, to detect image motion caused by relative motion between the receiver and the scene from the detected information.

Abstract: A pair of simple phase-sensitive full-wave high-gain demodulator circuits generate an output for both halves of an AC reference cycle. One of the demodulator circuits is utilized as an amplifier to drive, for example, the steering system servo valve in an aircraft steering system and the other demodulator drives a dummy load which has a resistivity approximately equal to the resistivity of the servo valve coils. The output current from both demodulators are compared, for example, by an opto isolator or coupler which generates corrective and/or warning signals in case a system failure occurs. In one embodiment, the sensor output loop is maintained at a predetermined voltage level above ground so that an open circuit in the sensor loop is detected by additional sensing circuits.

Abstract: Disclosed is apparatus for forming and directionally positioning a neutron beam. The apparatus includes an enclosed housing rotatable about a first axis with a neutron source axially positionable on the axis of rotation of the enclosed housing but rotationally fixed with respect to the housing. The rotatable housing is carried by a vertically positionable arm carried on a mobile transport. A collimator is supported by the rotatable housing and projects into the housing to orientationally position its inlet window at an adjustably fixed axial and radial spacing from the neutron source so that rotation of the enclosed housing causes the inlet window to rotate about a circle which is a fixed axial distance from the neutron source and has the axis of rotation of the housing as its center.