Abstract: A device for measuring the acoustic absorption properties of materials such as liners for jet engines has a first housing, an acoustic driver configured to provide acoustic energy to the first housing, a second housing attached to the first housing, and an acoustic driver configured to provide acoustic energy to the second housing. Acoustic sensors are used to measure the acoustic energy emitted from the two housings and to measure the absorption of each of the housings.

Abstract: The present invention is embodied in ceramic matrix composites with porous interfacial coatings and the methods and processes for fabricating such coatings integral with the ceramic matrix composites. Each ceramic matrix composite of the present invention includes a fibrous substrate or fabric material with a porous interfacial coating. The coating, prior to processing, is comprised of a coating solution made of a carbon precursor and a ceramic precursor resin dissolved directly within a solvent or solvents. Fabrication is achieved by first desizing the fibrous substrate, second immersing the desized fibrous substrate in the mixed coating solution, third evaporating the solvent and curing the precursor and resin via a low temperature cure, and fourth pyrolyzing the coating via a high temperature pyrolysis, preferably in an inert atmosphere. Next, the coated fibrous substrate is combined with a ceramic matrix composite (CMC).

Abstract: A semiconductor window which is transparent to light in the infrared range and which has good electrical conductivity is formed of a prefabricated semiconductor sheet bonded to a substrate material by optical contact. The sheet is a substantially uniformly doped wafer sufficiently thin that inherent absorption bands do not affect transmission. The sheet is contact bonded to the surface of an undoped transparent substrate without diffusion, growth or deposition on the surface. Windows having particular optical band pass characteristics are formed utilizing a zinc selenide substrate and a gallium arsenide sheet.

Abstract: A fluid regulator including compression member adapted to engage a fluid conduit, a biasing element operably connected to the compression member and producing a sufficient amount of biasing force to cause the compression member to deform the conduit to a substantially closed state, and a control device for applying a control force to the compression member. The control force may partially overcome the biasing force applied to the compression member and maintain the compression member such that the fluid conduit is maintained in a partially open state.

Abstract: A synthetic magnetodielectric composite material for absorbing electromagnetic radiation has a sheet of fabric having first and second surfaces. The fabric is formed of an insulating material. Magnetically permeable thread is disposed within the fabric. The magnetically permeable thread comprises a material having a permeability substantially greater than the permeability of free space. The fabric is impregnated with resin. The magnetically permeable thread is configured to provide predetermined permittivity and permeability within a selected frequency range, so as to provide desired absorption/transmission of electromagnetic radiation.

Abstract: A method and an apparatus for increasing detection signal-to-noise ratio, by reducing the effect of optical scatterers from a holographic storage medium, are disclosed. The method comprises the step of sensing the phase of scattered radiation and the subsequent step of writing the hologram data into the holographic storage medium. The image containing the hologram data is written with phase characteristics such that, during a subsequent hologram readout, the electric fields from the image and scatterers are 90 degrees out of phase. This optimum phase relationship greatly reduces the effect of scatter noise, thereby increasing signal-to-noise ratio and reducing bit-error-rate.

Abstract: In accordance with the present invention, there is provided a low observable aerodynamic control system for integrated use with an aircraft fuselage. The control system is provided with a shadow structure having an inner sloping region and an outer sloping region. The inner sloping region defines a shadow structure concavity. The outer sloping region is attachable to the aircraft fuselage. The control system is further provided with an aerodynamic control device having a body portion and a base portion. The base portion is disposed within the shadow structure concavity. The body portion extends from the base portion beyond the shadow structure concavity.

Abstract: A means for identifying a particular range and Doppler shift signal in the field of view of a moving radar antenna which determines azimuth angle to this range-Doppler signal relative to the antenna by determining the phase difference between said signal as processed through two channels each fed by antennas displaced in a horizontal direction with respect to the axis of the antenna system.

Abstract: The present invention relates to a laser pointing and tracking system which forms and maintains a small laser spot size at a selected aimpoint on a target and compensates for optical distortion in the intervening media. The invention comprises an illumination laser for directing a first wide divergence beam of short-pulse laser radiation toward a stationary or moving target. The target reflects a portion of the incident beam as return radiation which is interfered with a properly-timed short-pulse reference beam on an electronic radiation detector array. The detector array signals are processed to produce an electronic hologram which is imposed as a phase pattern on a spatial light modulator. A laser reads out the hologram to direct a beam of radiation at the target. Multiple sequential illumination and hologram formation/readout steps produce a small spot size at the selected aimpoint. The small spot is maintained at the aimpoint during the duration of an engagement by repeating the above steps.

Abstract: A method of forming an acoustic attenuation chambers within a honeycomb core. The honeycomb core have a plurality of honeycomb cells having interconnected side walls. A plurality of septum layers are spaced from one another within the honeycomb cells to define acoustic attenuation chambers between the septum layers and the side walls of the honeycomb cells. Each of the septum layers have an associated ablating wavelength and is transparent to the ablating wavelengths of the other septum layers. A laser beam having a laser wavelength is directed towards the septum layers. The laser beam is selectively absorbed by a septum layer which has an associated ablating wavelength equal to the laser wavelength to ablate apertures therethrough without ablating other septum layers.

Abstract: A remotely operable radio frequency jamming device having a jamming transmitter and a local controller in communication with a remote commander. The local controller has a signal receiver and decoder component for receiving, decoding and causing by electronic command the device to perform a remotely initiated instruction signal. In particular, the receiver and decoder component of the local controller can receive and decode a remotely initiated instruction signal to activate or inactivate the jamming device and thereafter cause by electronic command the activation or deactivation of the device. To effectuate the jamming of enemy radio signals, the receiver and decoder component of the local controller can receive and decode a remotely initiated instruction signal to transmit a selected jamming band from the transmitter of the jamming device, and thereafter cause by electronic command the transmitter to transmit the selected band.

Abstract: An electrical bus assembly distributes high current electrical power to a plurality of different devices simultaneously. The electrical bus assembly has a busbar assembly having an electrical conductor and a plurality of studs. At least one multi-contact connector is mounted to the busbar assembly and has a plurality of individual pin contacts in electrical communication with one another, so as to facilitate the transfer of electrical power therethrough. An array of such bus assemblies, defining an electrical power distribution module is also disclosed.

Abstract: In accordance with the present invention, there is provided a method for adhering a first ceramic foam to a second ceramic foam. The method begins with impregnating a liquid resin with reinforcement fibers to form a liquid reinforced bonding resin. The liquid reinforced bonding resin is then applied to at least one of the ceramic foams. The foams are joined to each other with the liquid reinforced bonding resin disposed therebetween. The liquid reinforced bonding resin is cured to form a solid reinforced bonding resin. The solid reinforced bonding resin is pyrolyzed for adhering the first and second ceramic foams to form a ceramic bonding layer. The ceramic bonding layer is characterized by a porous ceramic matrix with reinforcement fibers disposed therein.

Abstract: The present invention relates generally to the field of optical devices and particularly to embodiments of a three-stage PPLN optical parametric oscillator/difference-frequency generator configuration. The present invention allows simultaneous generation of three wavelengths in efficient use of the pump signal. The structure of the first embodiment of the present invention comprises a first PPLN element having first and second grating regions, and a second PPLN element having its own grating period. An input coupler is positioned at the input and exit ends of a resonator cavity and the first PPLN element is positioned between the input coupler and the second PPLN element. A second embodiment of the present invention includes a single PPLN element having three separate grating regions. The single PPLN element is positioned between input and output coupler mirrors. A third embodiment of the present invention includes a single PPLN element having three grating regions.

Abstract: An adaptive ramp mechanism for an aircraft having a fuselage which includes a fuselage skin, an interior cavity, a forward end and an aft end, and at least one door attached to the fuselage and moveable between an open position exposing the interior cavity and a closed position enclosing the interior cavity. The ramp mechanism comprises a ramp structure which is attached to the fuselage between the forward end and the interior cavity thereof.

Abstract: A non-chrome process for the pretreatment of substrate surfaces to simultaneously clean them and improve their bonding strength for organic coatings such as adhesives, protective primers, sealants, paints, composites and similar materials conventionally bonded to such substrates, including non-chromated or chromated curable organic resin protective coatings applied directly to bare aluminum substrates. The invention involves the use of novel wipe solvent compositions containing a major volume of an environmentally-safe volatile organic solvent which has a low composite vapor pressure or is otherwise exempt from federal, state or local regulations, and a minor volume of a polyfunctional coupling agent, preferably of the silane type.

Abstract: A compact broadband log-periodic antenna for transmitting and receiving frequencies between 0.5 to 18 GHZ. The antenna comprises two dielectric substrates bonded together, both substrates comprise a first group of dipole elements configured in a log-periodic sequence and a second group of serpentine configured dipole elements fabricated on the same substrate and in electrical communication with the first group of elements. The serpentine dipole elements are configured in a specific pattern such that the size of the antenna is reduced, yet still maintains log-periodic characteristics. Disposed between the two substrates is a feed system in electrical communication with both groups of elements such that a connector from a transmitter or receiver can be in communication with the antenna.

Abstract: In accordance with the present invention, in an aircraft storage container which is used for the transport of cargo items, defines an enclosed interior compartment and includes a hatch for selectively accessing the interior compartment, there is provided an improvement of the aircraft storage container. The improvement is provided with a high strength flexible bag member disposed about a substantial portion of the interior compartment for distributing force in response to explosive forces emanating from cargo items within the bag member. The bag member includes an opening and is positionable within the interior compartment such that the opening is adjacent the hatch for allowing cargo items to be placed into and removed from within the bag member via the hatch and the opening. The improvement is further provided with a bag opening frame which is attachable to the opening of the bag member and formed to receive cargo items for storage within the bag member therethrough.

Abstract: A double-balanced monolithic microwave integrated circuit mixer is fabricated on a GaHs substrate with a radio frequency microstrip balun formed thereon and a local oscillator microstrip balun formed thereon. A crossover diode ring is also formed upon the substrate. The radio frequency microstrip balun and the local oscillator microstrip balun provide enhanced electrical isolation between a radio frequency port and a local oscillator port, enhanced spurious response suppression, and enhanced local oscillator noise rejection in only 0.021".times.0.048" of circuit area.

Abstract: A process is provided for forming a fiber-reinforced resin structure having an opening therein by vacuum bag forming. A resin infusion port is disposed adjacent a mold surface. The resin infusion port has a resin inlet and at least one resin outlet. A fiber-reinforced ply is distributed adjacent the mold surface about the resin infusion port. A flexible covering is placed over the fiber-reinforced ply and the mold surface to form a chamber therebetween. The chamber is evacuated. Resin is dispensed into the resin infusion port through the resin inlet. The resin is infused into the ply by dispensing resin into the chamber from the resin infusion port through the resin outlet. The resin is cured within the resin infusion port and within the chamber to form a cured resin structure which is subsequently removed from the mold surface. An opening is formed in the resin structure by removing the resin infusion port and a portion of the resin structure adjacent the resin infusion port.