Abstract: An optical waveguide with one or more coatings of reactants specific to species to be analyzed in a liquid analyte immersed therein. A light signal carried by the waveguide undergoes interaction either with the bulk analyte whereby a first signal in connection with the bulk analyte is obtained and, simultaneously, with a layer of complex resulting from the reaction of one of said specific reactant with one of said species or with two or more complex layers corresponding to two or more of said species, this generating a second (or more) signal to provide the required analytical information on said species.

Abstract: A method of detection of microbial growth which comprises preparing a culture of an organism, analysing a portion taken from the whole culture in a pyrolysis mass spectrometer, and monitoring the relative height of the peak in the mass spectrum corresponding to mass of 60 daltons, an increased height of the said peak relative to the remainder of the spectrum being indicative of growth of the microorganism.

Abstract: A method of monitoring changes of redox activity in a medium in vitro or in vivo which comprises placing into the medium a probe having a non-metallic surface exposed to said medium and whose surface admittance varies with the redox activity in said medium, and detecting the resulting changes in the surface admittance of said probe. The method is particularly suitable for predicting or detecting the onset of ovulation in female mammals.

Abstract: Light valve for use in the projection of an image in which a liquid crystal is addressed by an electron beam produced in a column (10). The vacuum interface of the light valve (12) consists of an electrically inhomogenous structure (54) of fine conductors arranged within an insulating matrix. The invention is concerned with the method of manufacturing the light valve vacuum interface to permit high resolution to be obtained, the method comprising filling holes in a glass capillary array, as currently used for filtration of liquids with a molten metal or alloy, and allowing the liquid to cool. The filling is effected by placing the glass capillary array in an evacuated chamber and forcing the molten alloy into the holes in the array under pressure.

Abstract: Magazine for introducing samples into the inlet system of a mass spectrometer. The magazine (22) comprises a flat plate having upper and lower surfaces which are generally horizontal during use. A zig-zag groove (32) is formed in the lower surface engageable by a reciprocable pin (34) to advance the magazine (22) by increments relative to an aperture (12) of the inlet system (10) of the mass spectrometer and recesses (24) are formed in the upper surface of the magazine for receiving tubes (16) containing samples for analysis. The recesses (24) extend transversely to the direction of movement of the magazine (22) and are arranged at a regular pitch equal to that of the groove (32) in the lower surface.

Abstract: The introduction of a sample into a mass spectrometer providing in one aspect a method which comprises placing the sample in a tube (16) open at only one end, placing around the tube (16) an O-ring (30), placing the sample tube (16) with its open end adjacent an aperture (12) of the inlet system of the mass spectrometer and compressing the O-ring (3) about the tube whereby to seal sample tube (16) against the aperture (12), the sample tube upon evacuation by the inlet system of the mass spectrometer forming part of the vacuum retaining wall. The invention also relates to a sample tube surrounded by an O-ring and preferably containing a boat for receiving the sample.

Abstract: A feed system for picking a sample tube off a magazine and introducing the sample tube into the inlet system of a mass spectrometer. The feed system comprises a pick-up tube (52) designed at its forward end to fit over a sample tube (16) resting on the magazine (22) and grip the sample tube (16). A carriage (40) supports the pick-up tube in a horizontal attitude and is driven towards and away from the inlet system (10) of the mass spectrometer by means of a motor driven pinion (46) engaging a rack (44) on the upper surface of the carriage (40). A cam track (50) raises the pick-up tube (52) after a sample tube (16) has been gripped to the level of the aperture (12) of the inlet system (10).

Abstract: The invention relates to an inlet system for use in a mass spectrometer which comprises a capillary tube 10 for introducing ions for analysis into the ion source of the spectrometer. An expansion chamber 14 arranged at the end of the capillary tube 10 has an aperture sealingly connectable to a tube 16 containing a sample to be analyzed. A piston 18 disposed within the expansion chamber 14 acts as a closure member for opening and closing the said aperture. A pumping line 25 is provided for evacuating the expansion chamber 14 to low vacuum after communication is established between the expansion chamber and the sample tube 16 and the piston 18 seals off the pumping line from the expansion chamber 14 after a low vacuum has been achieved in the latter chamber to permit evacuation of the expansion chamber to 14 a higher vacuum by way of the capillary tube 10 to a diffusion pump evacuating the space within the mass spectrometer.

Abstract: A circuit for generating a timing signal in a Manchester decoder comprises an oscillator 10, a frequency divider 14 for dividing signals derived from the oscillator, and a comparator 18 for comparing the times of transitions in the output signal of the divider with transitions in input Manchester data. To form a digital phase locked loop, gates 12 and 16 are provided for selectively adding a pulse to and subtracting a pulse from the pulses applied to the divider 14 by the oscillator 10 in dependence upon the relative timing determined by the comparator 18, in such manner as to lock the phase of the output signal of the divider onto the phase of the Manchester data. A squelch circuit is also provided for inhibiting phase control by the comparator 18 in response to a drop in signal strength of the received signal containing the Manchester data.

Abstract: A thin-film, high pressure fuel cell comprising at least one oxygen electrode and at least one hydrogen electrode separated by thin-film hydrophilic membranes wetted with a solution of electrolyte, each electrode comprising a hydrophobic porous membrane coated with a thin film of noble metal catalyst and having conducting elements associated therewith, said arrangement of electrodes, membranes and conducting elements being subjected to a gas pressure of 500 to 20,000 psi.

Abstract: The invention relates to a method and a jig for constructing a carcase-type article of furniture. A panel which is to form a part (e.g. a door) of the finished article, is placed down on a horizontal surface. A jig is assembled around the panel using the panel as a template, the jig incorporating abutment blocks to contact the edges of the panel and locating blocks in predetermined positions relative to the abutment blocks to define the positions of the carcase walls and to locate the walls in position while being secured to one another. The carcase walls are cut to the desired size, and placed edge down within the locating blocks of the jig. Securing the walls to one another now forms a carcase the walls of which are correctly aligned with the edges of the panel.

Abstract: The invention relates to the manufacture of cadmium sulphide solar cells.A cell is formed of a glass substrate 10, a front contact 12 made, for example, of tin oxide, a cadmium sulphide layer 14 and a copper sulphide layer 16. the junction between the layers 14 and 16 is photovoltaic. In order to form a rear contact 18 on the copper sulphide layer, the invention proposes vapor depositing a mixed layer of copper and copper oxide onto the sulphide layer. The invention also describes a method of heat treatment following the formation of the rear contact in order to optimise the electrical performance of the cell.

Abstract: The invention relates to the manufacture of a cadmium sulphide photo-voltaic device. A substrate such as a glass is coated with successive layers which are made, in order, of tin oxide, cadmium sulphide, cuprous sulphide and copper to build up a photo-voltaic junction. In order to achieve a fast deposition rate of the cadmium sulphide while achieving a well ordered crystal structure the cadmium sulphide layer is deposited in two stages, the first involving spraying of a weak precursor solution and the second a substantially more concentrated solution to achieve at least a five times increase in the deposition rate. The invention also describes improved techniques for spraying and reducing the effects of the resistivity of the tin oxide first electrode.

Abstract: An analyte in solution is made to react with a specific reactant coated on the wave-guide thus modifying the optical properties thereof. The index of refraction of the wave-guide material is higher than that of the reaction medium which ensures that a light signal injected into said guide be carried by multiple total reflection, the distance of penetration of the evanescent wave associated with the totally reflected signal being of the same order of magnitude or greater than the thickness of the analyte-reactant product layer.