Abstract: A composite comprising a ceramic matrix having immersed ceramic reinforcing fibers is strengthened and toughened by providing a multi-layer ceramic coating surrounding each fiber. The multiple layers in the fiber coating are not bonded to one another. As a result, the multiple layers separate from one another in the presence of an advancing crack in the ceramic matrix, thereby permitting the fibers to pull out of the matrix and avoid premature fiber breakage. The choice of materials for the fiber coating is not limited by any requirement to establish a particular type of chemical bond between the coating and the fiber. Instead, the invention relies only upon the mechanical tendency of the unbonded multiple layers in the fiber coating to separate to promote fiber pull-out from the matrix in the wake of an advancing crack.

Abstract: The invention is a single-bath electrolytic de-oxidation and anodization process in which a workpiece surface such as an aluminum surface is electrolytically de-oxidized and then anodized to form an adhesive oxide layer in the same electrolytic chemical bath without removing the workpiece from the bath. Upon completion of the anodization step, the piece is rinsed in a water bath. The invention further includes recirculating the electrolytic bath through a filter to suppress contaminant levels in the bath to prevent metal ion or organic contaminants from the de-oxidation step from compromising the integrity of the anodization step.

Abstract: Silane polymer coating compositions which have excellent bonding properties for metallic surfaces and which make such surfaces highly resistant to corrosion. The compositions are formed by anhydrously reacting an epoxy trialkoxy silane with a primary amino trialkoxy silane in a stoichiometric molar ratio which provides one epoxy group for reacton with each primary amino hydrogen site to form the silane polymer coating composition. The composition is applied to the metal surface, and is hydrolyzed and dehydrated in situ to crosslink thereon and bond to the surface to form the corrosion-resistant coating.

Abstract: A gravity assisted open system for coating porous refractory substrates with a highly uniform layer of graphite or other material. Pyrolytic dissociation of downwardly flowing precursor gases in an inert atmosphere, countercurrent to an upward direction of transport of the porous refractory substrate, promotes infiltration of dissociated species of the precursor gases into pores and cavities of the porous refractory substrate. The infiltrated species collide with and condense on the surfaces of the pores and cavities of the upwardly moving porous refractory substrate to form a homogenous coating having particular electrical, mechanical, and optical properties. The open configuration of the system allows coating of specimens of porous refractory substrate material at substantially atmospheric pressure, which reduces startup and shutdown transient conditions which affect the uniformity of the coating and its properties, and which provides for coating porous refractory substrates at production rates.

Abstract: An aircraft having vertical takeoff and landing capability having at least first and second laterally extending paddle wheels rotatable on a central axis generally perpendicular to the longitudinal axis of the aircraft and between its nose and tail. Each of the paddle wheels has a plurality of blades pivoted by a system of linear actuators to a determined optimum blade pitch angle. One paddle wheel is positioned adjacent the port side of the aircraft and the other paddle wheel is positioned adjacent the starboard side. The pilot is able to operate the aircraft in all regimes of flight by differentially adjusting the pivot angle of each of the blades. In one embodiment utilizing only a pair of paddle wheels, differential operation of the blades provides lift, thrust, roll, and yaw control of the aircraft, while an aircraft pitch control rotor rotatable about a vertical axis distant from the paddle wheels is provided for controlling pitch of the aircraft.

Abstract: A device for the angularity of a hole has a housing, a pivotally movable probe, and a digital display for displaying angular deviation of the probe from a home position. The device can additionally or alternatively have a signaling device to signal angular deviation of the probe past a predetermined angular deviation.

Abstract: A polymer composition having intense magnetic properties and a method for preparation of same. A phthalimide compound and an aromatic dialiphatic acid are reacted in the presence of a metal catalyst at elevated temperatures to form a phenylenebis diphthalimidine compound. The phenylenebis diphthalimidine compound is then reacted with 3-benzylidine phthalimidine and a metal salt of an aliphatic acid at elevated temperatures under an inert gas to form the intensely magnetic polymer. The reactions may be carried out in the presence of a solvent.

Abstract: An unmanned air vehicle system which is intended for launch from a platform such as an aircraft or a ship and to follow other than a ballistic trajectory includes a pair of substantially similar air vehicles in a tandem relationship. A unitary tubular airframe is provided coextensive with both air vehicles. The nose of a second air vehicle is nested in the tail member of a first air vehicle. A rocket booster is mounted in the tail of the second air vehicle and ignited for launch of both air vehicles as a unit. Thereafter, a pyrotechnic separating mechanism is actuated for bisecting the tubular airframe intermediate the tail member of the first air vehicle and the nose of the second air vehicle. Following separation, each air vehicle has a gas turbine engine which is ignited for powering its associated air vehicle to its destination.

Abstract: A pattern recognition apparatus and a method for operating same. The apparatus includes a volume holographic medium (4) having a plurality of Fourier-space volume holograms representing pattern templates stored within. The apparatus further includes a spatial light modulator (1) and a phase encoder (2). The phase encoder has an output optically coupled to the medium by a first Fourier transform lens (3). The spatial light modulator spatially modulates a spatially uniform laser beam (7) in accordance with an unknown pattern. The two-dimensional phase encoder causes the spatially modulated laser beam to be spatially distributed prior to application to the medium. The apparatus further includes a detector (6, 11) having an input optically coupled by a second Fourier transform lens (5) means to an angular spectrum of plane waves generated by the medium in response to the output of the spatial modulator, phase encoder, and first Fourier lens.

Abstract: A radiation detection system includes an array of radiation detectors disposed on a common substrate of type-n silicon, wherein each detector includes an electrode spaced apart from the silicon by silicon dioxide. Two rows of the detectors are coupled by two rows of transfer gates to a common row of diodes for reading out data from any one or ones of the detectors which are individually addressable by row and column conductors. The transfer gate electrodes of contiguous pixels are connected together to form a row conductor. The gates are electrically activatable to provide electrical connection for receiving data of a detector only during a readout interval, and provide electrical insulation of the detectors at all other times. This inhibits blooming. Detector windows may be fabricated of thinned chrome or aluminum layers, or of polysilicon arranged to provide free spaces through which ultraviolet radiation can propagate into the detector.

Abstract: A fastener installation for securing a composite member to a structure. The fastener installation includes a shear member adhesively bonded to a surface of the composite member, and a pin member extending through the shear member and composite member to engage a fastener bore of a structure member and a securing member. The pin member engages a bearing surface of the shear member in bearing contact, and extends through an opening in the composite member spaced from the composite member. Shear forces are transferred between the composite member and the pin member through the adhesive bond, the shear member, and the bearing surface, rather than by bearing contact between the pin member and the composite member. An end of the pin member engages the securing member and acts in cooperation with a head of the pin member to apply compressive force to the composite member, thereby securing the composite member to the structure.

Abstract: A ceramic fiber/ceramic matrix composite has ceramic fibers and a porous coating on the fibers. A ceramic matrix contacts the porous coating, the fiber and coating being immersed in the ceramic matrix. The porous coating is selected from the group including Si.sub.3 N.sub.4, SiC, ZrO.sub.2, Al.sub.2 O.sub.3, SnO.sub.2 and Ta.sub.2 O.sub.5. The pores are generally empty so as to render the coating frangible to promote fiber de-bonding and pull-out in the wake of an advancing crack in the matrix. In order to keep the pores empty, a non-porous sealing layer is formed over the porous coating which closes the pores without filling them. The ceramic matrix remains generally outside of the pores, whereby said pores remain empty after the fiber and coating are immersed in the ceramic matrix.

Abstract: A spatial light modulator comprises a plate of non-ferroelectric PLZT ceramic. An array of pixels is formed by depositing a reflecting coating in the desired array on one side of the plate. A longitudinal electric field is applied so that the light entering the plate from the side opposite the reflecting coating experiences a polarization-independent refractive index change when the electric field is applied as it propagates parallel to the electric field. The required voltages may be decreased when a partially reflecting coating is deposited on the side opposite the reflecting coating. Grooves in the plate effectively isolate the pixels from electrical and mechanical crosstalk.

Abstract: An imaging device has a lens for focusing light and a sensor for imaging that light. The lens is selected such that the focus coverage area projected from the lens is much greater in area than the area of the sensor. The sensor is moved through the coverage area of the lens linearly along mutually perpendicular axes that are also perpendicular to the axis of the lens allowing the field of view of the lens to be systemically scanned by the sensor utilizing only linear translational motion of the sensor.

Abstract: A star tracker for generating positional information for a vehicle includes a holographic telescope (150) having one or more fields of view for imaging stellar objects. The telescope includes a plurality of radiation detectors (100) and an input aperture comprised of a primary holographic optical element (HOE) (134). The primary HOE provides one or more wavefronts to one or more secondary HOEs (136), each of which applies a chromatic correction so as to correct for a chromatic aberration induced by the primary HOE. A single or multiple field of view Schmidt telescope embodiment is also disclosed having one or more aspheric corrector plate HOEs and one or more associated concave spherical reflectors.

Abstract: A miniature accelerometer is fabricated using integrated circuit manufacturing and silicon micromachining techniques to form a closed loop, force balance sensor utilizing a silicon proofmass formed from and connected to a layer of silicon by a split flexure etched therein. The sensor circuitry detects AC signals coupled from the proofmass to a pair of electrodes formed on glass surfaces anodically bonded to the silicon layer. A DC restorative force is applied to the electrodes in response to the detected AC signals to balance acceleration forces applied to the proofmass. The sensor design is highly symmetrical.

Abstract: Process for producing novel water-base coating compositions and for applying such compositions to metal surfaces to render them corrosion-resistant, comprising reacting an epoxy trialkoxy silane with a primary aminotrialkoxy silane in a molar ratio providing one epoxy group for reaction with each primary amino hydrogen to form a hydrolyzable siloxane precursor coating composition which is solubilized, such as by the presence of a volatile organic weak acid and hydrolyzing said precursor compound in situ on a metallic surface to form a silanol precursor compound which is bonded to a metallic surface and is simultaneously cross-linked with itself and/or with external crosslinking agents under dehydration conditions to form a corrosion-resistant conversion coating or bonding coating having exceptional durability.

Abstract: In a process for forming composite laminate parts from reinforcing fibers and resin, a mold is selected which has a mold cavity having a part definition surface therein and a resin passageway leading to the cavity. An expansion member capable of expanding to a larger volume in response to heat is located in the cavity in conjunction reinforcing fibers which will form a part of the composite laminate part. The mold cavity is closed and resin is injected through the resin passageway to saturate the fibers. The expansion member is heated to expand the expansion member an amount sufficient to consolidate the resin and the reinforcing fibers between the expansion member and the part definition surface to shape the fibers and the resin into a component laminate part mimicking the shape of the part definition surface and to expel any excess resin from the cavity to the passageway.

Abstract: A retro-reflective target tape comprising a lower sub-laminate having an upper transparent thick mylar backing about 2 mils thick, a release sheet therebeneath and a pressure sensitive adhesive therebetween; and an upper sub-laminate having an upper light reflective sheet with a thin, transparent mylar backing about a half mil thick therebeneath and with a pressure sensitive adhesive therebetween and with pressure sensitive adhesive beneath the thin mylar backing, the upper sub-laminate being cut to form a plurality of circular reflective targets and removed from the lower sub-laminate except for the plurality of circular reflective targets, the pressure sensitive adhesive above the release sheet remaining with the thick mylar backing upon the removal of the adjacent release sheet. Also disclosed is a method of fabricating such tape.