Abstract: A method and a circuit for detecting transmission of a radio frequency (RF) signal and generating control signals to regulate the operation of a RF converter remotely located from a corresponding transmitter are disclosed. The method comprises the following steps: (a) sensing the direction of a RF signal flowing in an RF transmission line, at a location proximate of the RF converter; (b) generating a low-power RF signal in response to the sensed direction; and (c) transforming the low-power RF signal into a control signal to regulate the operation of the RF converter.

Abstract: In accordance with the present invention, there is provided a pair of opposing wings for providing aircraft directional stability of a delta-shaped aircraft having a longitudinal axis. Each wing is provided with a substantially straight swept-back leading edge. Each wing is further provided with a lower surface which extends aft from the leading edge. A lower airflow channeling portion is formed into the lower surface. The lower airflow channeling portion is generally elongate and concave and is disposed substantially parallel to the longitudinal axis of the aircraft for channeling airflow substantially parallel thereto.

Abstract: An extended reaction acoustic liner for use in jet engine noise mitigation has a substantially non-porous outer layer, a honeycomb core disposed in laminar juxtaposition to the outer layer, and a porous inner layer in laminar juxtaposition to the honeycomb core such that the honeycomb core is sandwiched between the outer layer and the inner layer. The honeycomb core comprises a plurality of cell walls defining a plurality of cells. Some of the cells are in fluid communication with one another via the openings formed in the cell walls. The openings in the cell walls cause viscous acoustic losses, resulting in acoustic energy dissipation and enhanced noise attenuation.

Abstract: An integrated, layered armor structure having multiple layers which alternate in their exhibited characteristics between extremely hard and ductile. The extremely hard layers of the armor structure are designed to shatter an impacting projectile, or pieces thereof, and to fracture in such a way as to dissipate at least a portion of the kinetic energy associated with the projectile pieces and to disperse the projectile pieces and hard layer fragments over a wide area. The ductile layers of the armor structure are designed to yield under the force of impinging projectile pieces and hard layer fragments from an adjacent hard layer. This yielding dissipates at least a portion of the remaining kinetic energy of these pieces and fragments. Pieces and fragments not possessing sufficient kinetic energy to tear through the ductile layer are trapped therein and so stopped.

Abstract: A system is provided for filling a gap between adjoining coplanar first and second sheet members mounted on an outer surface of a common substrate and having juxtaposed first and second edge surfaces. A permanent gap filler member of predetermined shape and size intended for eventual permanent reception in the gap is employed for partially filling the gap. A temporary gap filler tool which includes a substitute gap filler element having substantially the same predetermined size and shape of the permanent gap filler member, has an abutting surface for contiguous engagement with the first edge surface of the first sheet member when advanced to an attached position before the permanent gap filler member is mounted in the gap, a minor gap surface facing opposite said abutting surface, and means for releasably attaching the temporary gap filler tool to the first sheet member. A minor gap is thereby defined between the temporary gap filler element and the second edge surface of the second sheet member.

Abstract: A method for manufacturing a honeycomb structure includes applying an electron beam curable polymer material to a generally planer material, placing two sheets of the planer material in laminar juxtaposition with one another, and forming and curing nodelines between adjacent sheets of the planar material with an electron beam.

Abstract: A technique is provided for passively detecting the presence and location of an underground object. A plurality of individual antennas positioned in a linear array are directed to receive fields of view which are mutually parallel in azimuth. The linear array is then focused at a plurality of different angles in azimuth for passively acquiring low level random noise signals in the RF spectrum which are emitted by the underground object and by the intervening media.

Abstract: In accordance with the present invention, there is provided a variable camber delta-shaped aircraft. The aircraft is provided with an integrated fuselage/wing generally defining the aircraft and having longitudinal and lateral axes. The fuselage/wing has a forward section which is rotably attached to an aft section about the lateral axis. The aircraft is further provided with an aerodynamic lifting surface which is disposed about the fuselage/wing and defined by a camber. The forward section has a downwardly deflected position when rotated relative to the aft section. The forward and aft sections are cooperatively formed to increase the camber of the lifting surface when the forward section is in the deflected position.

Abstract: A series of arc lamps is ignited sequentially while maintaining a specified voltage on one side of each lamp with dielectric insulation on the high voltage side.

Abstract: A method of rendering a surface of a metal substrate substantially acid impervious. The method includes first placing the surface in a field of treatment, then depositing a mixture of a high-temperature resistant polymer particulate such as polyamide particulate and a curable powder adhesive on the surface, and finally subjecting the surface-coated metal substrate to a curing treatment sufficient to cure the powder adhesive and thereby adhere the polymer particulate as a film on the surface. A steel substrate coated in accord with the present methodology is particularly useful as a curing fixture upon which resin-impregnated fiber of polymer composite material is placed to thereby give molded parts made therefrom a desired shape. Production of a part is accomplished by vacuum bagging the composite material to the steel fixture and curing the so-produced part in place on the fixture in an autoclave at an elevated temperature.

Abstract: A method of dynamic memory reclamation for reclaiming memory leaks is disclosed, in which inaccessible heap segments are reclaimed without recompilation or relinkage of an application. The method comprises intercepting a call from an application to allocate or deallocate a heap segment, forwarding the call to the memory manager, passing the memory allocation and deallocation information from the memory manager to a file, performing a conservative garbage collection process using the memory allocation and deallocation information in the file to detect inaccessible heap segments, and calling to the memory manager from the file to deallocate the inaccessible heap segments. These steps are repeated periodically.

Abstract: The present invention is embodied in an apparatus and method for generating fatigue spectra on a chosen aircraft for which a Finite element model is available and for which a library of external load summations at key interfaces and key fundamental parameters are available from an aeroelastic analysis. The fatigue spectra generation system of the present invention represents a profile of stresses endured by the aircraft due to numerous events, such as ground and maneuver events, occurring during the life of the aircraft. The system calculates a total stress based on load and unit conditions associated with outside events by factoring up the unit conditions to derive individual stresses for each event and by summing all unit conditions.

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 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: Plasma spraying of particulate thermotropic liquid crystalline polymers onto the surfaces of composite and metallic structures. The present plasma spray process employs a conventional direct current electric arc plasma spray gun in which an inert plasma gas is introduced, caused to swirl, and discharges as a rotating plasma flame having an exceptionally high temperature, above about 14000.degree. K, into which the particulate liquid crystal polymer is discharged for melting and propulsion onto the target surface. The target surface preferably is preheated, and the molten particles deposit and cool to form a build up of the desired thickness. Cooling is regulated by post-heating the deposit to a temperature between about 200.degree. F. and 500.degree. F.

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.