Abstract: A plurality of electrodes having a light-transmitting property are formed in a striped pattern on one surface of an insulating substrate having a light-transmitting property. Then, light-shielding films are formed in such a manner that the light-shielding films are formed adjacent to the edges of each electrode along the long sides thereof, or at least one portion of each light-shielding film is made to overlap each edge of the electrode along one of the long sides thereof. Successively, light is applied from the back-surface side of the insulating substrate by using the light-shielding films and a photomask as masks so that spacers are formed in a state where they are self-aligned with respect to the light-shielding films.

Abstract: A speech training aid compares a trainee's speech with models of speech, stored as sub-acoustic word models, and a general speech model to give an indication of whether or not the trainee has spoken correctly. An indication of how well the word has been pronounced may also be given. An adult operator enters the word to be tested into the training aid which then forms a model of that word from the stored sub-word speech models. The stored acoustic models are formed by first recording a plurality of words by a plurality of trainees from a given list of single words. These recordings are then processed off-line to give a basic acoustic model of an acceptable or correct sound for each phoneme in the context of the pre-and proceeding phonemes. The acoustic models are Hidden Markov Models. The limits of acceptable pronunciation, applied to different words and trainees, may be adjusted by variable penalty values applied in association with the general speech acoustic model.

Abstract: A method and apparatus for monitoring a gaseous environment for the presence of cellular material capable of providing a measure of presence and/or numbers of cellular microorganisms, such as bacterial cells, in a large volume of air such as in a warehouse or production facility or in an open air location where bacterial presence is suspected. The method and apparatus are particularly suited for determining the likelihood of pathogenic material being present in an environment by batch or on-line measurement of cell numbers. On-line measurement provides continuous monitoring of an environment for presence of pathogens. The device includes a continuous flow luminometer preferably fed by a cyclone or high velocity virtual impactor and lytic and luminescence reagents which detect the amount of ATP or adenylate kinase present in a sample of air.

Abstract: A method for the detection of chemical agent present in a material comprising exposing a calixarene, having redox active substituents on its para rim, to a solution or suspension derived by admixture of all or some of the material with a liquid measuring any change in electrical behavior of the calixarene during or after exposure to the solution or suspension as compared to a reference condition, and relating such change in electrical behavior to the presence of chemical agent. Preferably, the calixarene exposed to the solution or suspension is a calix?4!arene or general formula (J), wherein Y.sup.1 to Y.sup.4 are independently selected from hydrogen, alkyl, alkenyl, aryl, aralkyl or a redox active substituent and R.sup.1 to R.sup.4 are independently selected from hydrogen, alkyl, alkenyl, aryl, aralkyl, or a polymerisable moiety, wherein at least one of Y.sup.1 to Y.sup.4 is a redox active substituent.

Abstract: A mid-infrared emitting diode with a substrate which is transparent to radiation produced by the device by virtue of the Moss-Burstein shift which is induced in the substrate by heavy doping. Emission from the device takes place via said substrate with a significant increase in external efficiency due to avoidance of obscuration by metallic contact.

Abstract: A twisted nematic type of liquid crystal device comprises two cell walls enclosing a layer of a nematic or long pitch cholesteric liquid crystal material. The device has both an alignment direction and a surface tilt provided by an asymmetric grooves structure alignment on one or both walls. The alignment treatment may be provided by a shaped layer of a photolithographic material. Embossing, ruling, or transferred from a carrier layer material may alternatively provide the alignment. The amount of twist may be multiples of about 90.degree. and the device arranged between two polarisers.

Abstract: A liquid crystal display element using ferroelectric liquid crystal includes a light blocking thin film which is formed by silicon or silicon-germanium solid solution by evaporation between electrodes formed by an ITO film placed in a striped pattern on a surface of a transparent glass substrate so that the thin film does not protrude from the ITO film surface. This thin film shades a non-pixel region as a black matrix.

Abstract: An optical component having a protective layer provided on a surface thereof, the protective layer preventing the component from being damaged by high velocity impacts from small particles or water droplets. The protective coating comprises a layer of gallium phosphide deposited onto the component surface using plasma assisted chemical vapour deposition (PACVD), an intermediate layer of PACVD boron phosphide, and an outer layer of PACVD diamond-like-carbon.

Abstract: A ferroelectric liquid crystal device comprises a layer of a ferroelectric liquid crystal material contained between two cell walls carrying electrode structures and a surface alignment treatment. The surface alignment is provided by a profiled surface, e.g., a grating, on at least one cell wall. The grating may be a monograting or a bigrating, with a symmetric or asymmetric profile. Such a profiling enables surface tilt and alignment anchoring energy to be independently arranged to suit liquid crystal material and device type to give a required molecular arrangement and low device defect. The grating may be provided by interferography, photolithography, embossing, ruling, or carrier layer transfer. Alignment directions on the cell walls may be parallel or non-parallel. The surface tilt on both cell walls may be the same or different values. The cell walls may be relatively rigid, e.g., glass slides, or flexible, e.g.

Abstract: The present invention relates a method for the detection, identification and/or quantification of plant or animal tissues, microorganisms or cell free RNA or DNA and to detector apparatus adapted for performing said method. The method particularly uses Total Internal Reflection Fluoresence (TIRF) to measure hybridization of analyte RNA or DNA with RNA or DNA that is associated with an evanescent wave detector waveguide.

Abstract: An all-solid-state laser comprising a slab (1) of gain medium, a diode laser pump system (3) configured in an end pumping geometry with the gain medium (1) and a heat sink thermally contacted to the gain medium (1) wherein the diode laser pump system (3) and the gain medium (1) are cooperably arranged so that in use a positive thermal lens is capable of being formed within the medium, the gain medium (1) having a thickness (d-d') made as small as possible while permitting the substantially unhindered passage through the slab of the laser mode established between the two mirrors (M1, M2).

Abstract: A radiation sensor (10) for the microwave and millimeter-wave regions incorporates a lens (12) having two parallel focal planes (26a, 36), these being defined by a polarization-selective reflecting PIN diode array (18) within the lens (12). One focal plane (26a) is occupied by a receive array of crossed dipole antennas which mixes receive signals and a local osicllator signal to produce intermediate frequency signals for subsequent processing. The second focal plane (36) is occupied by a transmit antenna array of separately activatable polarization switching antennas arranged to define a range of transmit beam directions. A second PIN diode array (20) protects the receive antenna array from the transmit beam.

Abstract: A method of applying a stable intermetallic diffusion barrier layer to a metallic article is described. In many instances, protective coatings are incompatible with the material of the substrate to which they are applied. Such incompatibility is overcome in the invention through in situ formation of an intermediate stable diffusion barrier layer by sequential deposition and subsequent reaction of suitable metals to form a continuous intermetallic layer. A conventional overlay coating may then be applied to the intermetallic layer without risk to the underlying substrate. The invention also contemplates creation of unitary diffusion barriers from multi-layer deposits; deposition of plural diffusion barriers, and formation of complete protective systems comprising substrate, diffusion barrier(s) and overlay coating prior to heat treatment in situ.

Abstract: A segmented ring transducer comprising a plurality of arcuate ring sections (21) coupled together, each section (21) comprising a plurality of rectangular piezoelectric ceramic blocks (22) arranged into a stack (27, 28) with one or more tapered wedges (23) spaced in the stack, the piezoelectric stack (27, 28) being assembled between opposed end couplings (24, 25), pre-stress bolts (26) connecting together the opposed end couplings (24, 25) in each ring section (21) to hold together each ring section assembly (21). The arcuate ring sections (21) can be identical. Adjacent ring sections (21) can be connected together by further bolts. Alternatively, the ring transducer can be formed as a split ring with an arcuate portion (20) of the ring missing, the arcuate portion being formed by omitting either one or more arcuate ring sections (21) or an arcuate portion (20) of the ring which is not equivalent to an integral number of arcuate ring sections (21).

Abstract: The invention provides a liquid crystal device having an aligned and surface tilted liquid crystal layer contained between two cell walls. The cell walls carry electrodes for applying voltages across the layer thickness to provide a display. The alignment is provided by a layer of a material that undergoes optically induced ordering during cross linking. That is, a material capable of aligning liquid crystal molecules after cross linking with polarized light. One such material is polyvinylcinnamate. The aligning layer is profiled with an asymmetric grating, eg approximately sawtooth in cross section by interferometer, oblique incidence photolithography, or embossing. The shape of the grating provides the surface tilt. The liquid crystal material may be nematic, cholesteric, or smectic.

Abstract: The invention provides a ferro-electric liquid crystal display (FLCDs) with reduced voltages requirements for driver circuits. This enables standard drivers circuits designed to rms address twisted nematic type of displays, to be used for FLCDs. Displays are formed by cells containing smectic liquid crystal material. The cell walls are surface treated and carry e.g. row and column electrodes forming an x,y matrix of addressable display elements. The smectic liquid crystal material switches between two states upon application of a dc pulse of appropriate amplitude, polarity, and time. Addressing waveforms are strobe waveforms, e.g. two pulses of opposite polarity in successive time slots, applied to each row in turn. Data waveforms are, e.g. dc pulses of alternate polarity with each pulse lasting one time slot ts. Two data waveforms are needed to switch between the two states; one data waveform is the inverse of the other. Typically a strobe waveform pulse may be 50 volts.

Abstract: A method of making a boron carbide article by sintering includes mixing boron carbide with an epoxidized resin in solution and drying to form a granulated homogenized mixture and a carbonization cycle in which the mixture is maintained at at least two constant temperatures for predetermined times. The rates of temperature rise are at controlled rates sufficient to allow outgassing of the gases evolved during the decomposition of the resin.

Abstract: Ammunition round comprising a primary cartridge (1) and a secondary cartridge (2) provided with mutually cooperable push fit connection means for connecting the two cartridges during loading. The cartridges (1, 2) incorporate sockets (10, 12) which contain and are connected by a connecting piece (14). Socket (12) includes a cavity (20) having sufficient longitudinal depth to allow some axial movement of the connecting piece (14) ensuring that strain on the connecting piece (14) during loading is minimized.

Abstract: A multi-functional epoxy resin with good high temperature properties allowing prolonged service at temperatures above 120.degree. C. is derived from a precursor of formula (I): ##STR1## in which R.sup.3 to R.sup.8 inclusive are independently selected from hydrogen, C.sub.1 to C.sub.3 alkyl or halo-alkyl and R.sup.9 is hydrogen, alkyl or halogen, and in which n has the value 0, 1 or 2. The precursor (I) may be self-coupled or cross-coupled with precursors of other epoxy compounds of the TGDDM type. Such cross-coupling gives rise to a complex mixture containing not only the mixed product, but also the self-coupled products of each constituent. Regardless of the precise chemical make-up of the mixture, the observed glass transition temperature is higher than for TGDDM resins formed without precursor (I). If the substituent at the R.sup.9 position is alkyl or halogen, oligomer formation is suppressed and a less complex mixture results.

Abstract: A multi-sensor flow-through system which mitigates or at least overcomes any cross field effects between different sampling conduits comprising a plurality of flow-through sample cells (2), wherein each sample cell (2) is provided in an independent and isolated sample channel (16a, 16b. . . ), whereby fluid flowing within each channel (16a, 16b, . . . ) is isolated from fluid flowing in neighboring channels (16a, 16b, . . . ). In one embodiment of the multi-sensor system, each sensor cell (2) operates as an autonomous and independent unit isolated from all other units. Ideally, each of the sample channels (16a, 16b, . . . ) are also independent and isolated from other sample channels (16a, 16b. . . ). The multi-sensor system can additionally have the exit end of the channels (16a, 16b, . . . ) feed into a well in such a way that free space is provided between the ends of the channels and the uppermost surface of fluid in the well.