Abstract: A data transmission network includes a number of access controllers connected to a central hub. The hub includes an arbitrator to select only one access controller for data transmission. Upon selection of one controller all other controllers are disabled to prevent collision of data packets. An interlock prevents enablement of a disabled controller until the data packet received by the transmitter has terminated to prevent transmission of part of a data packet. Synchronization between the data and a master clock is obtained by an initial coarse synchronization and a subsequent fine synchronization. The coarse synchronization is obtained by generation of a number of identical signals with a time delay between each signal. A clock pulse latches to one of the signal paths to provide the initial coarse synchronization.

Abstract: The invention provides a new structure for a subsurface junction field effect transistor (SJFET) and a new process for its fabrication, the process being especially compatible with existing processes for the fabrication of bipolar devices. Spaced zones of p.sup.+ type are diffused into an n-type epitaxial layer to terminate the channel and connect to source and drain terminals. Spaced zones of n.sup.+ type are diffused into the epitaxial layer to define the channel width. The corresponding zones for the bipolar device can be formed at the same time. A passivating layer of silicon dioxide is applied and the subsurface p-type channel formed by ion implantation to leave a thin n-type layer between the channel and the silicon dioxide layer. Upon application of a metal layer over the silicon dioxide layer in the neighborhood of the channel, and its connection to the back gate terminal, a stable electron accumulation layer forms at the surface of the n-type layer which interfaces with the silicon dioxide layer.

Abstract: A Metal-Oxide Semiconductor (MOS) high gain amplifying stage which overcomes the inherently low transconductance, gm, of MOS transistors is described. This is achieved by using a specially configured load transistor in combination with a driver transistor. The load transistor is provided, by means of positive feedback, with a current generator which is dependent on the output voltage of the stage and has an effective negative output conductance. The positive feedback is achieved by connecting an appropriate attenuation stage between the output and the input of the load transistor. By the cancellation of output conductances between the driver and load transistors, a near infinite voltage gain can be achieved despite resistive loading at the output of the amplifier. The MOS amplifying stage has application in amplifiers, comparators and oscillators.

Abstract: A composition for treating dental infections, e.g. dental caries caused by Strep. mutans, comprises a varnish containing an antimicrobial agent such as chlorhexidine acetate and benzoin gum in an orally acceptable liquid. The composition can be painted on teeth, allowed to dry thereon to give a transparent, translucent or tooth colored film which is effectively invisible but provides sustained release of the antimicrobial agent to the site of infection over a period of at least four days. The film can be removed at will, e.g. by application of the liquid varnish base.

Abstract: Catalysts for use in promoting heterogeneous chemical reactions, such as hydrogenation, cracking, dehydrogenation and Fischer-Tropsch reactions, are prepared by depositing a catalytically active metal such as nickel electrolytically onto an aluminum substrate in such a manner that the metal particles are deposited in micro-particulate form to enhance their catalytic activity. The aluminum substrate is prepared by cleaning and anodizing it, so as to deposit thereon an aluminum oxide surface film having micro porosity. Then the substrate is immersed into an electrolysis bath of solution of salt of the metal to be deposited, and subjected to alternating current electrolysis to cause the required deposition. Prior to use, the catalysts so prepared should be heated to remove absorbed gases from their porous surfaces.

Abstract: This invention relates to a process for the extraction of oilseeds and oilseed materials with two mutually immiscible solvents, the first solvent comprising a lower alkanol containing dissolved ammonia, and the second solvent comprising a lower alkane or halogenated lower alkane. The process yields two improved products, a proteinaceous meal of reduced glucosinolate content and a high quality triglyceride oil, both acceptable as food ingredients.

Abstract: The invention provides optical measuring apparatus including a laser which is arranged to have an output of electromagnetic radiation including at least two different simultaneously-generated frequencies. This output is fed to a detector, such as an optical diode, which produces a corresponding electric signal at the difference (beat) frequency. The beat frequency, any change in the beat frequency, or any rate of change of the beat frequency can now be examined electrically to the degree of accuracy generally available in that art, usually to a much higher degree than is available in the optical or mechanical arts. The parameter to be examined may be that of an element causing the production of the beat frequency such as a birefringent material, or may be that of an element which changes the frequency in some way, such as an angular orientation of two quarter-wave plates.