Abstract: An apparatus and method for filtering the effects of large amplitude signal fluctuations from elements of the cross-spectral density matrix of a detor array. The outputs of the array are sampled T times, and the values of each element of the matrix formed by using: ##EQU1## where Z.sub.li is the complex output of an sensor of the array at time i; Z*.sub.mi is the complex conjugate of the output of an array sensor at said time i; and k is an integer greater than 1. Because of the exponent k, small, relatively constant, terms will dominate, reducing the effect of large amplitude fluctuations. Preferably, the above value will be scaled according to: ##EQU2## which, besides being similarly filtered by the exponential terms, the resultant matrix element will have a magnitude corresponding to the actual power of the detected signal, after filtering.

Abstract: An optoelectronic system is provided for converting analog electrical sigs into digital electrical signals. An optical carrier produced by a laser source is separated into spectral components. An electro-optical modulator modulates the optical carrier with a radio frequency input signal so as to produce an amplitude modulated optical output signal. The optical output signal is then outputted to a wavelength division demultiplexer which separates the output signal into a plurality of separate channels, based on wavelength. Photodetectors connected to each of the channels convert the separated signals into analog electrical signals. These analog electrical signals are outputted to a plurality of standard analog to digital converters which convert the analog electrical signals into digital signals.

Abstract: Filamentous substrates are coated with diamond by a chemical vapor deposition process. The substrate may then be etched away to form a diamond filament, such as a diamond tube or a diamond fiber. In a preferred embodiment, the substrate is copper-coated graphite. The copper initially passivates the graphite, permitting diamond nucleation thereon. As deposition continues, the copper-coated graphite is etched away by the active hydrogen used in the deposition process. As a result a substrate-less diamond fiber is formed. Diamond-coated and diamond filaments are useful as reinforcement materials for composites, is filtration media in chemical and purification processes, in biomedical applications as probes and medicinal dispensers, and in such esoteric areas as chaff media for jamming RF frequencies.

Abstract: A process for producing the 2223 phase of (Pb,Bi)SrCaCuO that is much faster than existing processes has the steps of: calcining a precursor powder mixture while maintaining intimate mixing of this precursor mixture by intermediate grindings during calcination; compressing the calcination product into a consolidated body; and heating the calcination product while maintaining intimate mixing of the calcination product, to form essentially phase pure 2223 (Pb,Bi)SrCaCu). A fast process for making a (Pb,Bi)SrCaCuO part with a high J.sub.c has the steps of: pressing calcined and reacted (Pb,Bi)SrCaCuO powder into a green body having the shaped of the part; and sintering the green body for a selected time, most preferably between 6 and 8 hours, that is long enough to establish superconducting electrical contact between grains of (Pb,Bi)SrCaCuO but short enough to prevent void formation or part shape distortion. The part made by this process has a high density, at least about 4 or 5 g/cm.sup.3.

Abstract: A method and apparatus for real-time monitoring of particulates in a fluid. The fluid is illuminated, and an image formed of the interior of the fluid. The image is then detected, and processed to determine the size, shape, etc. of particulates within the fluid.

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: The broadband microwave frequency shifter is an electro-optical device that accomplishes frequency shifting, or translation by the use of serrodyning or mixing techniques. A first optical signal is modulated with the radio frequency signal desired to be translated and processed to produce an upconverted lower sideband optical signal. A second optical signal is frequency shifted using an optical phase shifter utilizing serrodyning techniques or by offset phase locking it to another optical signal. When the frequency shifted optical signal is combined with the upconverted optical signal and converted to an output radio frequency signal thereby producing an output microwave signal that duplicates the input microwave signal in all aspects except that its center frequency has been shifted.

Abstract: A filter, and method of the filtering, for increasing the signal to noise tio of relatively small and constant amplitude signals in the presence of relatively large and varying amplitude signals. The filter produces a filtered power level a.sub.z proportional to: ##EQU1## where x.sub.i are power realizations of the signal in a selected frequency bin, and i=1, 2, . . . , N, and z is a non-zero real number not equal to -1, 0, or 1, and is preferably positive. For positive z, because filtered power level a.sub.z depends on a sum of (x.sub.i).sup.-z, sum a.sub.z disproportionately favors smaller, more stable, signals.

Abstract: A film of a coating material is produced on a substrate by a pulsed laser deposition method in which the material that forms the coating material is first combined with a matrix material to form a target. The target is then exposed to a source of laser energy to desorb the matrix material from the target and lift the coating material from the surface of the target. The target and the substrate are oriented with respect to each other so that the lifted coating material is deposited as a film upon said substrate. The matrix material is selected to have the property of being more volatile than the coating material and less likely than the coating material to adhere to the substrate. The matrix material is further selected as having the property such that when the target is exposed to a source of laser energy, the matrix material desorbs from the target and lifts the coating material from the surface of the target.

Abstract: A displacement-type flow immunoassay is performed using a microcapillary sage. The inner wall of the microcapillary passage has immobilized thereon antibodies to the antigen of interest. Labeled antigen is immunologically bound to the immobilized antibodies. Sample antigen passing through the column displaces the labeled antigen. Downstream, the displaced labeled antigen is detected. The microcapillary format of the present invention enhances the sensitivity of the immunoassay over the sensitivity of displacement-type flow immunoassays performed in a column at similar flow rates.

Abstract: Improvement in resolution in terms of minimum feature sizes and proximity fects in an electronic mask is attained by making the mask using a high voltage electron beam which deflects or blocks backscattered electrons. The novel mask structure comprises a transparent support, an absorber layer disposed on said support, a dielectric layer disposed on said absorber layer, and a resist layer disposed on said dielectric layer. It is the dielectric layer which is credited for improving resolution in said mask which can be used a multiple number of times in printing a pattern for various applications, including electronic devices and integrated circuits.

Abstract: The extraction of phase information for radio frequency (RF) direction of rival is attained by pre-detect sensing and quantization of differential phase of a RF wave impinging on two or more antenna apertures, based on sensing and encoding differential phase without the use of conventional detection, and quantizing phase at or near the leading edge of a pulse signal. This is accomplished by detection of an intermediate frequency (IF) carrier, and encoding leading-edge phase (for each channel) in terms of near-phase-difference between two reference-oscillator readings containing the differential phase information--encoded as differential reference-oscillator phase. Precision angle-of-arrival is then derived from the measured differential reference-oscillator phase.

Abstract: The shape memory effect is displayed by near-equiatomic ruthenium alloys of Ta or Nb with compositions of Ta.sub.x Ru.sub.1-x where x can be as low as 0.38 and preferably x=0.44 to 0.63 and Nb.sub.x Ru.sub.1-x where x can be as low as 0.25 and preferably x=0.45 to 0.59 which exhibit a transition from the high-temperature cubic phase to a tetragonal phase. These alloys are prepared by melting together tantalum and ruthenium, or niobium and ruthenium, in the above mentioned ratios. A further embodiment of this invention is to alloy NiTi alloys with, one of these two ruthenium-based high-temperature alloys (i.e. either Ta--Ru or Nb--Ru) so as to obtain a similar behavior which will result in an increase in the transition temperature relative to unalloyed Ni--Ti.

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: Bulk crystalline materials are annealed by introducing into them mechanical energy of sufficient intensity to create a large amplitude sound wave. The mechanical energy may be introduced into the material, for example, by laser ablation. Where the bulk crystalline material is a doped semiconductor, the process also electrically activates the material.

Abstract: An immobilized substrate surface is chemically modified by manipulating an nzyme which is immobilized to a solid surface. Modifications include (1) chemical dissection of a substrate surface such as by chemical hydrolysis, (2) chemical synthesis on a substrate surface, and (3) chemical patterning of a substrate surface. The enzyme may be coupled to colloidal beads or particles, locally flat solid surfaces including planar, textured planar, cylindrical and spherical surfaces or arbitrary predefined shapes, or scanning probe microscope probes. In the patterning applications, colloidal particles containing the enzyme can be confined to desired regions of the substrate surface by various techniques which control the movement of the particles. The particles can be confined to tunnels or channels in a patterned polymer mold on top of the substrate surface. The enzyme can also be immobilized onto the surface of a raised pattern and this patterned surface can then be placed in contact with the immobilized substrate.

Abstract: Phosphors having a doped core are surrounded by a shell material. Additionally, these nanocrystalline phosphors, or larger phosphors formed by conventional or other processes may be surrounded by a shell that prevents or significantly reduces non-radiative recombination at the surface of the original phosphor.

Abstract: A method and apparatus for overcoming polarization induced signal fading in both heterodyne communication and interferometric sensing. An adjustable birefringent element in series with a linear-polarization beam splitter forms an elliptical-polarization beam splitter. The birefringent element controllably evolves the states of polarization of two input signals thereby controlling the power contribution of each signal onto the orthogonal axes used by the linear beam splitter. When the states of polarization are evolved such that there are equal signal to reference power ratios on the beam splitter axes, subsequent detectors generate a constant, optimum amplitude signal without the need for weighting or decision circuits.

Abstract: The present invention is a process for making a nanochannel glass (NCG) rica, having the steps of: coating a face of an etched NCG with a replica material (with or without an intervening buffer layer), where the etched NCG face has a plurality of channels arranged in a desired pattern, to form a replica coating on the NCG conforming to the pattern; and removing the replica coating from the etched NCG. The present invention is also the replica made by this process.

Abstract: A high power, highly efficient, phase-stable frequency-multiplying magnicon microwave amplifier is disclosed having efficiencies that exceed 60%. The magnicon amplifier has an output cavity that receives an electron beam that is deflection modulated by the drive, gain and penultimate cavities of the magnicon amplifier. The output cavity is dimensioned so as to operate in a TM.sub.m10 mode, where m is an even integer greater than two. The output cavity is selected to preferably have an operating frequency f.sub.o which is twice the cyclotron frequency f.sub.c of the output cavity.