Abstract: Disclosed is a planar dual mode microstrip filter with the coupling between similar modes on different patches governed by the spacing between the patches rather than by microstrip coupling lines between the patches. The patches are shaped to allow dual mode coupling. The materials used in building this filter were an alumina substrate with gold metalization. The filter is encased in a conducting box made from a conducting material. One advantage of the proximity coupled structure is that it reduces the number of parts, complexity and allows the filter to be realized in a smaller space than in previous dual mode designs. This filter is useful in satellite communications, radar, and cellular communications. High temperature superconductor materials can be used in a planar microstrip form.

Abstract: A wet-spinning fiber process which controls the micro-structure of the wepun fiber by varying the non-solvent/solvent miscibility and precipitation strength.

Abstract: A composite structure includes a self-supporting substrate and a thermal barrier coating of zirconia stabilized with scandia and yttria. A method of protecting the surface of a self-supporting substrate from degradation caused by exposure to temperatures above 1200.degree. C. includes the step of applying to the surface a coating of zirconia stabilized with scandia and yttria.

Abstract: A copolymer is formed from reacting, within a melt, a phthalonitrile resin with an epoxy resin having at least three epoxy groups. In an alternative embodiment, a copolymer is formed by reacting a phthalonitrile resin with an epoxy resin, at least one of the epoxy and phthalonitrile resins having a perfluorinated carbon. The copolymers of the present invention have exceptional thermal stability and a low affinity for water.

Abstract: A system that synchronously segments a speech waveform using pitch period and a center of the pitch waveform. The pitch waveform center is determined by finding a local minimum of a centroid histogram waveform of the low-pass filtered speech waveform for one pitch period. The speech waveform can then be represented by one or more of such pitch waveforms or segments during speech compression, reconstruction or synthesis. The pitch waveform can be modified by frequency enhancement/filtering, waveform stretching/shrinking in speech synthesis or speech disguise. The utterance rate can also be controlled to speed up or slow down the speech.

Abstract: An oxidation resistant fiber-reinforced composite is made by impregnating a fibrous material with a resin containing a linear polymer having a repeating unit with at least one carboranyl group, at least one silyl or siloxyl group and at least one acetylenic group. The linear polymer may then be cured to form a fiber-reinforced thermoset or may be pyrolyzed to form a fiber-reinforced ceramic. For additional protection of the fibrous material against oxidation, the fibrous material may be prewetted or coated, also with a linear polymer containing a linear polymer having a repeating unit with at least one carboranyl group, at least one silyl or siloxyl group and at least one acetylenic group, prior to being impregnated. The coating on the fibrous material may be cured to form a thermoset coating on the fibers or may be pyrolyzed to form a ceramic coating on the fibers.

Abstract: A method and apparatus for transporting a positive ion beam to a distant target. An ion channel is created as a path to the target, and the beam injected into the channel at a mildly-relativistic beam velocity. Because the beam is mildly-relativistic, the electric field caused by its positive charge propagates well in advance of the beam, attracting free electrons in the plasma channel and pulling them into the beam along its axis of propagation. The current which is initiated by this precursor electron flow, is sustained during the duration of the beam, and is then a combination of the beam current and additional current carried by the electrons within the channel. As a result, a magnetic flux circulates annularly about the beam of a sufficient magnitude to pinch the beam.

Abstract: The instant invention is a switch, comprising: (1) a pathway of a superconductive material; and (2) a ferromagnet, where the ferromagnet is adapted for having at least a first magnetization state and a second magnetization state, where fringe fields from the ferromagnet in the first magnetization state do not exceed a predetermined magnetic field in the superconductive pathway to convert at least a portion of the superconductive pathway to the normal state; where fringe fields from the ferromagnet in the second magnetization state exceed the predetermined magnetic field in the superconductive pathway to convert at least a portion of the superconductive pathway to the normal state.

Abstract: A porous material of desired porosity and pore size is made by mixing a piculate material and fungible beads that are thermally decomposable until the desired distribution is attained; compacting the mixed material and beads to form a green body that has sufficient strength to be handled where the beads are undecomposed; and compacting and heating the green body to fuse the material particles and to decompose the beads to gas.

Abstract: The present invention is a cyanate resin monomer having the formula:NCO--CH.sub.2 --(CF.sub.2).sub.n --CH.sub.2 --OCNwhere n is an even integer from 6 to 10, inclusive.Another aspect of the invention is an essentially pure cyanate resin mono having the formula:NCO--CH.sub.2 --(CF.sub.2).sub.n --CH.sub.2 --OCNwhere n=3, 4, 6, 8, or 10. Another aspect of the invention is a prepolymer made by the process of heating a monomer of the invention to a conversion below the gel point. Another aspect of the invention is a method for depositing an interlevel dielectric resin on an integrated circuit, having the steps: (a) coating the integrated circuit with a thin film of a prepolymer made by the process of heating a monomer of the invention to below the gel point, and (b) curing the prepolymer to at least the gel point. Another aspect of the invention is a low dielectric thermoset polymer resin made from these monomers.

Abstract: Phthalonitrile thermoset polymers and composites having flame resistance formed by combining a phthalonitrile monomer in the melt stage with a halogen-containing aromatic amine curing agent. The halogen-containing aromatic amine curing agent is selected from the group consisting of aromatic amine curing agents having the general formula:NH.sub.2 --(Ar.sup.2 O--).sub.y Ar.sup.1 --X--Ar.sup.1 (--OAr.sup.2).sub.y --NH.sub.2wherein Ar.sup.1 and Ar.sup.2 are substituted or unsubstituted aromatic groups, y is 0 or greater, and X is --C(CF.sub.3).sub.2 -- and aromatic amine curing agents having the general formula:NH.sub.2 --(Ar.sup.4 O--).sub.u Ar.sup.3 --Z--Ar.sup.3 (--OAr.sup.4).sub.u --NH.sub.2wherein Z is a connecting bond or a linking group other than oxygen or --C(CF.sub.3).sub.2 --, u is 0 or greater, and Ar.sup.3 and Ar.sup.4 are aromatic groups and wherein either Ar.sup.3 or Ar.sup.1 or both Ar.sup.3 and Ar.sup.4 are substituted with at least one halogen atom or halo-substituted alkyl group.

Abstract: A method and apparatus for extracting an object from an image, in which one locates a pixel within the image (the "central" pixel), and then sequentially compares the brightness of neighboring pixels, proceeding outward from the central pixel. In so doing, one determines the largest dropoffs in brightness between neighboring pixels, and uses these to determine a brightness threshold for extracting pixels belonging to the object. In a preferred embodiment, one determines the threshold by comparing the largest dropoffs, identifies overlapping regions of brightness level common to all the dropoffs, and sets the threshold at the midpoint of the common overlapping region.

Abstract: A fiber-reinforced phthalonitrile composite is made by impregnating or coating a fibrous material with a phthalonitrile prepolymer mixture containing a phthalonitrile monomer and an aromatic amine curing agent that is thermally stable and nonvolatile at a temperature up to about 375.degree. C., and that contains at least one electron withdrawing substituent effective to reduce the reactivity of the aromatic amine curing agent with the phthalonitrile monomer.

Abstract: A labeled compound detectable by IR spectroscopy contains at least one histidine residue bound to a cyanate or thiocyanate metal complex that has an IR absorption band within the spectral region of 2399-1900 cm.sup.-1. An assay reagent for simultaneously detecting or determining a plurality of different analytes in a sample is made up of a plurality of different labeled compounds, each being independently distinguishable from the others by absorbing energy in a different and distinguishable region in the range of 2300 to 1900 cm.sup.-1.

Abstract: A water spray mist is used to cool a compartment fire before discharge of a gaseous fire suppression. As a result, less water and less fire suppression agent is needed than required with conventional method of suppressing compartment fires. The water spray may be continued for a short time after initial discharge of the fire suppression agent, and may be restarted after the fire has been extinguished. Also, the present invention reduces the levels of toxic and corrosive gases in compartment created during the suppression of compartment fires by the use of a gaseous fire suppression agent.

Abstract: Ceramic structure having porosity of 10-80% is characterized by a solid cmic matrix having therein elongated and parallel channels, the structure is made by a process that includes the steps of:(a) arranging tows of elongated fibers parallel to each other to form a fiber preform,(b) contacting the fiber preform with a matrix precursor whereby the matrix precursor deposits around the fibers,(c) removing the fiber preform from the matrix precursor,(d) drying the fiber preform,(e) calcining the fiber preform,(f) hot pressing the structure containing the fugitive fibers therein, and(g) removing at least some of the fibers to form channels in the structure.

Abstract: The wavelength multiplexed, electro-optically controllable, fiber optic multi-tap delay line utilizes a first output signal from a plurality of amplitude adjustable continuous-wave (CW) optical lasers multiplexed to form a combined optical signal onto which a radio frequency signal is imposed thereby shifting the combined optical signal which is then demultiplexed. A second output signal of the plurality of CW lasers is phase adjusted and combined with the demultiplexed combined optical signal to form a RF phase adjusted modulated optical signal. The plurality of phase adjusted modulated optical signals pass through associated optical delay lines and are multiplexed to form a single optical signal containing a plurality of optical channels having different characteristics which is applied to a detector to produce an output electrical signal for transmission to using devices.

Abstract: The sonar array post processor employs an adaptive processing, known as matched beam processing, in the beam domain which takes analog or digital conventional beamforming outputs from a sonar array, multiplies them by a set of adaptive weighting coefficients and produces a new set of beams. The new output beam of highest intensity yields the ideal maximum signal gain and correct target bearing. Continuous target tracking provided by the sonar array post processor in the endfire direction of a horizontal line array minimizes the towing ships maneuvers and for, a bottom mounted surveillance system, a smaller number of arrays are required.

Abstract: A material test specimen design is taught for the determination of critical train and stress states for multiaxial fracture. The objective of the specimen is to increase the amount of data obtained per specimen while retaining simplicity in testing procedure by using standard tension testing machines to generate the primary deformation of the specimen. The specimen, in conjunction with analytical or computational simulation, uses nonuniform deformation fields produced by secondary and tertiary strain concentrations to generate and track these multiaxial strain states to fracture. Typically, the primary deformation is uniaxial tension of a panel, the secondary strain concentration is a circular hole in the panel and the tertiary strain concentrations are areas of reduced thickness within the deformation field of the circular hole. Multiaxial strain ratios from -0.50 to -0.10 and control over fracture initiation sites may be generated by a test specimen design of the type taught by this invention.

Abstract: The interferometric fiber optic accelerometer is viewed as a mass-spring transducer housed in a sensor case. The sensor case is attached to a moving part whose motion is inferred from the relative motion between the mass and the sensor case. A flexural disk is housed in a sensor case which is accelerated in a direction normal to the plate surface. The plate undergoes displacement resulting in strains on the plate surface. A coil of optical fiber, made to be part of an optical interferometer, is attached to the flexural disk, the strain from the disk is transferred to the fiber thus changing the path length of the fiber interferometer. The interferometer output in demodulated providing the acceleration response. The design of the accelerometer housing is such that it is highly immune to extraneous signals, i.e., dynamic and hydrostatic pressure.