Abstract: An electromechanical transducer for the generation of an electric signal in response to a force or motion applied to the tactile surface thereof. The electromechanical transducer comprises a stack of planar sheets of a piezoelectric polymer material, each sheet having two opposed broad flat faces and at least one tactile surface at one longitudinal end, separate electrodes covering portions of each flat face of the sheets in predetermined patterns, terminals electrically connected to said electrodes for passage of said electric signal and means for detecting and amplifying the electric signal generated in response to a force or motion applied to the tactile surface of the transducer.

Abstract: There is described a gas chromatographic assembly formed on a semiconductor wafer by etching techniques. There is also described an improved thermal detector for use therewith.

Abstract: Stabilized quadrivalent cation oxide electrolytes are employed in fuel cells at elevated temperatures with a carbon and/or hydrogen containing fuel anode and an oxygen cathode. The fuel cell is operated at elevated temperatures with conductive metallic coatings as electrodes and desirably having the electrolyte surface blackened. Of particular interest as the quadrivalent oxide is zirconia.

Abstract: Hollow fiber reactors for growing microbial cells. Isotropic hollow fibers are supported in a housing inoculated with cells. Nutrient medium passing through the lumen undergoes a pressure drop resulting in radial convective flow: the nutrient medium flows outwardly from the lumen into the surrounding area adjacent the entry port and fluid surrounding the hollow fiber flows into the lumen adjacent the exit port. With the efficient distribution of nutrients and removal of product, high cell densities are achieved providing for high product yields per unit reactor volume.

Abstract: An acoustic microscope and method are disclosed in which an object under investigation is excited by two energy sources. Acoustic waves are propagated from the heated area of the object and the waves are detected and analyzed.

Abstract: A method for synthesizing reaction products, such as hydrocarbons, from fluid reactants is provided by use of a solid state electrochemical cell. A preferred embodiment may be used to produce methane at a substantially enhanced, controllable rate.

Abstract: The method of generating XUV radiation which involves exciting atoms to a storage level, irradiating the excited atoms and raising them to a higher level and allowing the atoms to lase to a lower level other than ground which is simultaneously emptied.

Abstract: A tactile stimulator is disclosed which comprises a stack of planar sheets of a piezoelectric polymer material, which in the preferred embodiment is PVF.sub.2. Each sheet has two opposed broad flat faces and at least one tactile surface at one longitudinal end. Separate electrodes cover portions of each flat face of the sheets in predetermined patterns. The electrodes from sheet to sheet are mirror images of the corresponding electrode patterns of the next adjacent sheet. Each of the sheets is polarized in the direction of its tactile end such that upon application of a voltage across the electrodes of that sheet, the sheet will longitudinally extend its tactile surface.

Abstract: Electrochromic material for an electro-optic display includes an oxide of at least one transition metal having a structure related to a hexagonal tungsten bronze structure whereby ions of an electro-active material readily diffuse through the lattice structure. In a display the electrochromic material is positioned between two electrodes with an electrolyte between and contacting the electrochromic material and one electrode which comprises the electro-active material.

Abstract: The wavelength of an optical pump beam is down converted to a longer wavelength in a Raman active gaseous medium by stimulated Raman scattering. The Raman active gaseous medium is contained in the space between a pair of optical reflectors of an optical resonator of the type for producing a focus of the optical beam energy at a point intermediate the length of the resonator within the Raman active medium to enhance conversion of pump energy into the output longer wavelength of the Stokes wave. The pump beam is directed into the optical resonator at an angle to the optical axis of the optical resonator such that the optical beam path is folded back and forth within the optical resonator to cause the beam spot to walk over the surfaces of the reflectors and out of the optical resonator.

Abstract: An acoustic apparatus and method for microscopic imaging and spectroscopy. The apparatus includes a plurality of devices for exciting an object of interest so that acoustic waves are propagated from the object. These devices include lasers, x-ray sources, microwave generators, ultraviolet sources, and electric current generators. The acoustic waves propagated from the object of interest are detected and the object of interest and the acoustic wave detector are moved with respect to each other in a raster scanning pattern. The magnitude of the detected acoustic waves and the corresponding raster pattern of the object are recorded so that a visual image of the object can be obtained. In addition, the frequency of the exciting electromagnetic radiation that excites the object can be varied so that both the absorption spectra and the Raman frequency mode of the object can be determined.

Abstract: Disclosed is a thermophotovoltaic converter which includes a parabolic cone radiation concentrator portion and a processor portion including a radiator which absorbs concentrated radiation and generates incandescent radiation. A photovoltaic cell in close proximity to the radiator receives the incandescent radiation and generates an electrical voltage. The cell includes an intrinsic or lightly doped silicon substrate having a top surface for receiving radiation and a bottom surface having a plurality of diffused N and P conductivity regions arranged in rows. A titanium-silver layer overlays the bottom surface and conductively interconnects regions of one conductivity type and provides a reflective surface to photons which pass through the substrate.

Abstract: A programmable read only memory (PROM) includes a first plurality of conductive lines, a second plurality of conductive lines and polycrystalline silicon material therebetween. At the crossing points of the first and second plurality of lines doped regions are provided in the polycrystalline silicon in contact with a second line and which extend at least partially through the material. To provide a diode interconnect at any crossing point, the associated region is irradiated by a laser beam to either cause diffusion of dopant atoms to the underlaying conductive line or activate implanted ions, thereby electrically interconnecting the first and second lines through a diode. The PROM is readily fabricated as part of a monolithic integrated circuit or electrical array and can be programmed after completion of the fabrication process.

Abstract: Low resistance, doped polycrystalline semiconductor connection patterns are fabricated by scanning a doped polycrystalline layer with a laser beam thereby increasing the crystal grain size, reducing defects in the grains, increasing charge carrier mobility and as a result reducing material resistivity. Semiconductor devices having increased circuit density and speed are realized through use of laser annealed polycrystalline semiconductor resistors, contacts and interconnections.

Abstract: A tunable source of infrared radiation is obtained by irradiating an assemblage of Raman active gaseous atoms or molecules with a high intensity pumping beam of coherent radiation at a pump frequency .omega..sub.p to stimulate the generation of Stokes wave energy at a Stokes frequency .omega..sub.s and to stimulate the Raman resonant mode at the Raman mode frequency .omega..sub.R within the irradiated assemblage where the pump frequency .omega..sub.p minus the Stokes frequency .omega..sub.s is equal to the Raman mode frequency .omega..sub.R. The stimulated assemblage is irradiated with a tunable source of coherent radiation at a frequency .omega..sub.i to generate the output infrared radiation of the frequency .omega..sub.0 which is related to the Raman mode frequency .omega..sub.R and the input wave .omega..sub.i by the relation .omega..sub.0 =.omega..sub.i .+-..omega..sub.R. In one embodiment the interaction between the pump wave energy .omega..sub.p and the tunable input wave energy .omega..sub.

Abstract: A cryptographic system transmits a computationally secure cryptogram over an insecure communication channel without prearrangement of a cipher key. A secure cipher key is generated by the conversers from transformations of exchanged transformed signals. The conversers each possess a secret signal and exchange an initial transformation of the secret signal with the other converser. The received transformation of the other converser's secret signal is again transformed with the receiving converser's secret signal to generate a secure cipher key. The transformations use non-secret operations that are easily performed but extremely difficult to invert. It is infeasible for an eavesdropper to invert the initial transformation to obtain either conversers' secret signal, or duplicate the latter transformation to obtain the secure cipher key.

Abstract: A method of and apparatus for imaging objects utilizing acoustic waves wherein an acoustic beam or beams are generated at one or more frequencies and are focused into proximity with the object to generate output acoustic energy at a different frequency or frequencies resultant from nonlinear interactions with the resultant production, after detection and conversion to electric output signals, of high resolution, enhanced images.

Abstract: An acoustic scanning apparatus is described having an acoustic grating for scattering waves into a focused beam. Surface acoustic waves are generated by a chirp signal generator and are introduced along one surface of the scanning apparatus. These waves propagate along the surface, are scattered by the acoustic grating and are thereby converted into bulk acoustic waves. The bulk acoustic waves converge into a focused beam inwardly directed at an angle to the surface acoustic waves. The focused beam scans at substantially the same speed as the surface acoustic waves traveling along the surface of the apparatus. The acoustic grating can also be used to convert bulk waves to surface acoustic waves as either a variable chirp rate generator or a variable pulse compression filter.

Abstract: Method and apparatus for making a hologram that controls both the amplitude and the phase of a reconstructing beam of light at each point on the surface of the hologram. The hologram is a transparency made from a conventional, color reversal photographic film that has multiple emulsion layers that are each selectively photosensitive to light of different wavelengths. The desired image to be produced from the hologram is initially processed into a matrix of Fourier transformed amplitude coefficients and a matrix of Fourier transformed phase coefficients. The hologram is made by first exposing the photographic film to an illumination pattern of the Fourier amplitude coefficients using light having a spectrum to which one of the emulsions is selectively photosensitive. The film is next exposed to an illumination pattern of the Fourier phase coefficients using light having a wavelength to which another emulsion of the film is selectively photosensitive.

Abstract: A fan-shaped beam of penetrating radiation, such as X-ray or .gamma.-ray radiation, is directed through a slice of the body to be analyzed to a position sensitive detector for deriving a shadowgraph of transmission or absorption of the penetrating radiation by the body. A number of such shadowgraphs are obtained for different angles of rotation of the fan-shaped beam relative to the center of the slice being analyzed. The detected fan beam shadowgraph data is reordered into shadowgraph data corresponding to sets of parallel paths of radiation through the body. The reordered parallel path shadowgraph data is then convoluted in accordance with a 3-D reconstruction method by convolution in a computer to derive a 3-D reconstructed tomograph of the body under analysis. In a preferred embodiment, the position sensitive detector comprises a multiwire detector wherein the wires are arrayed parallel to the direction of the divergent penetrating rays to be detected.