Abstract: Homogeneous crystals are grown from a multicomponent melt double crucible assembly with an injector which affords improved flow of melt from the outer to the inner crucible. Guide rods are provided external to the outer crucible and locate the inner crucible with reduced probability of sticking. Means are also provided for withdrawing the inner crucible after crystal growth is complete as is a method of removing trapped gas from the apparatus prior to crystal growth.

Abstract: A liquid crystal display element is provided with a first insulating substrate having spacers and an alignment layer that covers the entire surfaces of the spacers, and a second insulating substrate having at least an alignment layer. The liquid crystal display element is arranged so that the first and second insulating substrates are bonded to each other by allowing the alignment layer on the spacers of the first insulating substrate and the alignment layer on the second insulating substrate to soften and adhere to each other by applying a pressure under heat, and liquid crystal is injected into the gap in between.

Abstract: An rf ion source suitable for low power operation over a range of pressures in air comprises discharge electrodes having one or more cathodes (1) and an anode (2). Each cathode (1) is connected to an rf signal supply (8) through an associated coupling means (4) and the anode (2) is adapted to provide a surface area over which a plasma discharge may occur that is not substantially greater than the total cathodal area over which the discharge may occur. In this way, the anode (2) presents no more useful surface than is required to accommodate the optimum area of the plasma discharge thereby preventing plasma wander and enhancing the stability of the discharge over known ion sources.

Abstract: A polymer having spontaneous polarization with the same codes as liquid crystal is introduced into a liquid crystal layer of the smectic liquid crystal cell so that the responding speed is improved (second liquid crystal cell). In another way, a polymer having spontaneous polarization with opposite codes to the liquid crystal is introduced into liquid crystal showing .tau.-V.sub.min characteristic so that a driving voltage is lowered (first liquid crystal cell). These polymers are previously added to a liquid crystal composite before injecting into the liquid crystal cell. In another way, after a photochemically polymeric monomer is added to the liquid crystal composite and the obtained product is injected into the liquid crystal cell, the monomer is polymerized by the projection of a light. Furthermore, the liquid crystal cell into which the polymer is introduced is heated again so as to show I phase and is cooled so that the tone display is realized.

Abstract: A method is provided for dyeing a non-cellulosic organic material with a dye, preferably a vat dye, comprising (a) treating the material with a dye in the presence of a reducing agent and an alkali and (b) oxidising the treated material produced in step (a) characterised in that the concentration of reducing agent used in step (a) is increased above that used for conventional vat dyeing such that the resultant dyed material has a lightfastness of 5 or more by BS 1006 B01 and B02 (1978) and/or has a washfastness or 5 or more by British Standard Test BS 1006 C06.C2 (1981). Preferably the step (a) is carried out in the presence of an alkali in concentration of at least 0.5 molar, more preferably 1 molar or more and most preferably 1 to 4 molar. The method provides vat dyed non-cellulosic organic materials having a reflectance of infrared light of wavelength 400 nm to 680 nm of less than 15%.

Abstract: There is disclosed a liquid crystal polyacrylate mono- or co-polymers having a repeat unit (I), wherein R.sub.1 and R.sub.2 are independently alkyl or hydrogen, R.sub.3 is alkyl, hydrogen or chlorine, m is 0 or an integer 1-20, W is a linkage group COO, OOC or O and X is a mesogenic group.

Abstract: Liquid crystal compounds of formula I may be used by themselves or they may be mixed with other liquid crystal compounds to give useful liquid crystal mixtures which may then be used in liquid crystal devices. The materials exhibit smectic mesophases and may therefore be used in ferroelectric, ferrielectric, antiferroelectric, themochromic and electroclinic devices. They may also be used as long pitch materials.

Abstract: A method of authenticating watermarked paper comprises the steps of transtly heating a first surface (50) of a watermarked sheet of paper (40) using a hot air source (22); forming a thermal image of the watermark (42) using a thermal imager (30); and analyzing the thermal image to determine whether or not the watermarked paper is authentic. The evolution of the thermal image with time is characteristic of the watermark and is dependent on the local thermal mass of the paper in the region of the watermark.

Abstract: The present invention describes liquid crystal compounds which are suitable for use in liquid crystal devices including those which exploit the electroclinic effect.

Abstract: The present invention provides novel peptides and vaccines containing them capable or inducing production of antibodies directed against Clostridium perfringens alph-toxin (CPa) in animals to which the) arc administered and thereby providing pro-phylazis against infection by Clostridium pefringens and/or the alpha-toxin itself. Particularly the present invention provides such a vaccine that is relatively safe and simple to produce. e.g. by genetic engineering means. Preferred peptides comprise theo amino acid sequence of Clostridium perfringens alpha-toxin from amino acid 247 to 370 but lack the epitopes necessary for phos-pholipase C and/or sphingomyelin hydrolysing activity round between amino acids 1 to 240 of that sequence. Further provided are antisera and antibodies raised to the peptides and vaccines of the present invention, and particularly monoclonal antibodies and hybridoma cell lines for their production.

Abstract: A digital processor for simulating operation of a parallel processing array incorporates digital processing units (P.sub.1 to P.sub.8) communicating data to one another via addresses in memories (M.sub.0 to M.sub.8) and registers (R.sub.11 to R.sub.41). Each processing unit (e.g. P.sub.1) is programmed to input data and execute a computation involving updating of a stored coefficient followed by data output. Each computation involves use of a respective set of data addresses for data input and output, and each processing unit (e.g. P.sub.1) is programmed with a list of such sets employed in succession by that unit. On reaching the end of its list, the processing unit (e.g. P.sub.1) repeats it. Each address set is associated with a conceptual internal cell location in the simulated array (10), and each list is associated with a respective sub-array of the simulated array (10). Data is input cyclically to the processor (40) via input/output ports (I/O.sub.5 to I/O.sub.8) of some of the processing units (P.sub.

Abstract: Apparatus for distinguishing between genuine and counterfeit articles whereby a first optical filter is applied to genuine articles and suspect articles are scanned with the aid of a suitable second optical filter. Scanning of genuine articles incorporating first optical filter with the aid of suitable second optical filter gives rise to optical effects which would not otherwise be apparent.

Abstract: Luciferase is conjugated to a chemical entity, particularly to a specific binding agent such as an antibody, antigen or a nucleic acid, and more particularly an antibody, by (a) mixing the luciferase with one or more of D-luciferin, magnesium ions and adenosine triphosphate and (b) performing a covalent coupling reaction between the luciferase and the binding reagent using a covalent coupling reagent where the amount of D-luciferin, magnesium ions and/or adenosine triphosphate is sufficient to protect the luciferase activity against inhibition by the covalent coupling reagent. Preferably, step (a) is carried out by mixing the luciferase with its substrates in solution and preferably both magnesium and adenosine triphosphate are present as magnesium adenosine triphosphate (Mg.sup.2+ ATP), optionally together with D-luciferin. Also disclosed is a labeled chemical entity comprising a chemical entity conjugated to active luciferase as formed by the method.

Abstract: Tracking means for establishing a line-of-sight between a control point to which the second craft is being guided and tracking the line-of-sight to follow the second craft and deriving a signal .sub.a representing the rate of rotation of the line-of-sight about the control point; monitoring means for deriving a signal representing the displacement e of the first craft from the line-of-sight, a signal representing the range R.sub.m between the first craft and the control point, and a signal representing the rate of change R.sub.m of the range R.sub.m, presetting means for providing a signal representing a positive quantity k; and a computer for deriving signals representing .sub.c, .sub.c, and k to satisfy the equation ##EQU1## and minimize the difference -.sub.a, k being initially set equal to k.sub.1 ; control means for deriving from the representations provided by the computer a signal representing f(e)+R.sub.m .sub.c +2R.sub.m .sub.

Abstract: A dynamical system analyser (10) incorporates a computer (22) to perform a singular value decomposition of a time series of signals from a nonlinear (possibly chaotic) dynamical system (14). Relatively low-noise singular vectors from the decomposition are loaded into a finite impulse response filter (34). The time series is formed into Takens' vectors each of which is projected onto each of the singular vectors by the filter (34). Each Takens' vector thereby provides the co-ordinates of a respective point on a trajectory of the system (14) in a phase space. A heuristic processor (44) is used to transform delayed co-ordinates by QR decomposition and least squares fitting so that they are fitted to non-delayed co-ordinates. The heuristic processor (44) generates a mathematical model to implement this transformation, which predicts future system states on the basis of respective current states. A trial system is employed to generate like co-ordinates for transformation in the heuristic processor (44).

Abstract: Compounds of formula (I) are usefully employed in pharmaceutical compositions either in a mixture or in association with a pharmaceutically acceptable carrier or diluent; ##STR1## wherein M is a diamagnetic metal atom or a diamagnetic metal compound of silicon or a compound of silicon or is 2H; one H being bonded to each of the two nitrogen atoms depicted as being bonded to M (positions 29 and 31 shown); R.sub.1 to R.sub.25 are the same or different and are independently selected from C.sub.1 -C.sub.20 alkyl, C.sub.2 -C.sub.20 alkenyl, X--O--Y, (a), X.sup.2 COOX.sup.1, X.sup.2 CONR.sup.1 R.sup.11 and H; wherein X and X.sup.2 are independently selected from a chemical bond, --(CH.sub.2).sub.n -- where n is an integer from 1 to 20 and --(CH.sub.2).sub.a CH.dbd.CH(CH.sub.2).sub.b where a and b are independently selected from integers 0-20 and a+b totals from 0 to 20; X.sup.1 is independently selected from C.sub.1-20 alkyl, C.sub.2-20 alkenyl and H, R.sup.1 and R.sup.11 are independently selected from H, C.sub.

Abstract: A radiation sensor for the microwave and millimeter-wave regions incorporates a lens having two parallel focal planes, these being defined by a polarization-selective reflector grid within the lens. One focal plane is occupied by a receive array of crossed dipole antennas with respective mixer diodes. One dipole of each antenna couples to a local oscillator signal and the other couples to a receive signal reflected by the grid. These signals are mixed by the diodes to produce intermediate frequency signals for subsequent processing. The other focal plane is occupied by a transmit array of separately activatable polarization switching antennas arranged to define a range of transmit beam directions. This focal plane may alternatively be occupied by a second receive array.

Abstract: A liquid crystal display element has pairs of light-shielding electrode films, each pair of which are selectively placed without contact with each other between adjacent transparent electrodes on one of the paired substrates along the long sides of each transparent electrode with overlapping portions with the long sides. The light-shielding electrode films have a conductivity, and are effective to reduce the resistance of the transparent electrodes. It also has wall-shaped spacers with a uniform height, each of which is formed between the adjacent transparent electrodes so as to have overlapping portions with the respective light-shielding electrode films. Here, the spacers have an insulating property and a light-shielding property. Moreover, the other portions except for the pixel aperture sections are shielded from light by either the light-shielding electrode films, the spacers, or black matrixes installed on the other substrate.

Abstract: The invention provides an addressing scheme with temperature compensation for temperature induced changes in liquid crystal material switching parameters. Temperature compensation is provided by measuring liquid crystal temperature, and varying the length of strobe waveforms accordingly. A ferroelectric liquid crystal cell is addressed by row and column electrodes forming an x,y matrix of display elements. A strobe waveform is applied to each row in sequence whilst appropriate data waveforms are applied to all the column electrodes. At each display element, the material receives an addressing waveform to switch it to one of its two switched states depending upon the polarity of the addressing waveform. The data waveforms are, e.g., alternating positive and negative pulses of period 2 ts. The strobe waveform has a zero for one time period ts followed by a unipolar voltage pulse of significant duration, e.g., equal to or greater than 0.25 ts or more.

Abstract: A superconductive junction (10) comprises a first track (22) of YBa.sub.2 Cu.sub.3 O.sub.7 surmounted by a second track (28) also of YBa.sub.2 Cu.sub.3 O.sub.7. An interconnect (26) in the form of a superconductive mesa electrically connects the first track to the second track and acts as a microbridge. When cooled below a critical temperature, the junction (10) shows Josephson-like behaviour. A non-superconductive layer (24) of PrBa.sub.2 Cu.sub.3 O.sub.7 separates the first track and the second track, with the interconnect extending through the PrBa.sub.2 Cu.sub.3 O.sub.7 layer in the form of an island. The junction (10) is fabricated by electron beam evaporation, optical lithography, and ion beam milling.