Abstract: A composition for treating dental infections, e.g. dental caries caused by Strep. mutans, comprises a varnish containing a dentally acceptable 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.To sustain further the antimicrobial agent in situ and hinder its egress into the oral cavity, a sealing composition may be applied over the varnish layer. The sealing composition is preferably solvated polyurethane which cures by evaporation of solvent.

Abstract: A method of extracting components from particulate materials is disclosed. The method includes the steps of mixing the particles with a first extraction solvent to provide a slurry. The slurry is then passed through an extraction zone. A second extraction solvent is passed countercurrently to the slurry through the extraction zone. The second solvent has a different density from the first solvent and is substantially immiscible with the first solvent. This process is particularly beneficial for use in the extraction of ground oil-seed particles.

Abstract: An apparatus simulates an electronic circuit having a number of circuit elements, each being coupled to an associated set of nodes, a pair of which are capable of carrying a current therebetween, such as transistors. The apparatus has a selection device to select a circuit element to be simulated. A first memory is coupled with the selection device for storing the characteristics of each of the transistors. A transfer device transfers the characteristics from the first memory to a first register. A second memory stores the voltage present at each of the nodes, while a retrieval device retrieves the nodal voltages from the second memory and transfers them to a second register. Coupled to the first and second registers is a computation unit to ascertain the current flowing between the current carrying nodes and the subsequent change of voltage at those nodes. The apparatus carries out the simulation over a series of incremental time steps thereby providing an analog simulation of the circuit.

Abstract: Water-soluble, amide group containing polymers such as polyacrylamide are modified, to render them easy to detect, by reacting the polymer in aqueous solution with organic dye molecules which can form stable carbo-cations reversibly in water. The labelled polymers can then be detected spectrophotometrically. An example of a suitable dye molecule is 9-xanthydrol.

Abstract: An apparatus is disclosed to simulate an electronic circuit having a number of circuit elements, each being coupled to an associated set of nodes, a pair of which are capable of carrying a current therebetween, such as transistors. The apparatus has a selection device to select a circuit element to be simulated. A first memory is coupled with the selection device for storing the characteristics of each of the transistors. A transfer device transfers the characteristics from the first memory to a first register. A second memory stores the voltage present at each of the nodes, while a retrieval device retrieves the nodal voltages from the second memory and transfers them to a second register. Coupled to the first and second registers is a computation unit to ascertain the current flowing between the current carrying nodes and the subsequent change of voltage at those nodes. The apparatus carries out the simulation over a series of incremental time steps thereby providing an analog simulation of the circuit.

Abstract: The invention provides a process for preparing magnetic recording material by depositing ferromagnetic material in particulate form into an aluminum substrate. The aluminum substrate is prepared by cleaning an aluminum or aluminum metal containing substrate; anodizing the cleaned metal substrate, to produce a suitably pitted or porous oxide substrate surface; and rinsing the anodized substrate, substantially to remove therefrom acid residues remaining from the anodizing step. The substrate in contact with a liquid solution of a salt of at least one ferromagnetic metal is then subjected to electrolysis with alternating current, to deposit the metal into the pores of the oxide in small-particle, ferromagnetic form while adjusting and controlling the frequency of the alternating current to obtain discrete particles in the pores assembled in an anisotropic configuration. Excess liquid solution is subsequently removed from the so-treated substrate.

Abstract: A data controller to control passage of data between a plurality of data handling devices comprises a communication link to permit communication of the devices with one another. An indicator is associated with each of the devices to indicate data is to be transmitted from any one of the devices. An inhibitor operates upon a device after it transmits data to inhibit access of that device to the communication link and to the indicator. A reset device is responsive to the indicator to remove the inhibitor when the indicator indicates that no data is to be transmitted.

Abstract: A probe for ultrasound testing or treatment of a molten metal comprises:an ultrasound-transmitting rod (10) of which one end is a "downstream" end (12) adapted to contact molten metal under test or treatment;a piezoelectric crystal (50) adapted to supply ultrasound to or receive ultrasound from the rod (10); androd-cooling means (16) located near to the downstream end (12) of the rod (10).A method for the treatment of a liquid metal melt, to reduce the number of inhomogeneous particles distributed through the melt comprises:creating a standing wave of ultrasound energy within the melt, e.g. using a probe as defined above, whereby the inhomogeneous particles concentrate, and are encouraged to coalesce, at the nodes of the standing wave; andseparating the coalesced particles from the bulk of the liquid melt.

Abstract: Sleep disorders in mammals, such as insomnia and narcolepsy, are treated by administering an effective amount of ethyl 4-acetoxybutanoate, or a closely related homolog thereof. The compounds may also be administered to mammals to cause muscle relaxation and as animal anaesthetics. Moreover the compounds appear to inhibit the release of dopamine in the brain, and are hence useful also in treatment of conditions which are associated with abnormalities of dopamine release and dopamine sensitivities, such as Parkinson's disease, schizophrenia and tardive dyskenesia.

Abstract: A process is provided for the separation of a solid into its constituent lyophobic and lyophilic components by comminution and agglomeration in liquids to which the two components are respectively lyophobic and lyophilic. The process has particular application in coal beneficiation wherein ash particles are liberated into a water phase and coal particles are agglomerated with oil. The operations of comminuting and agglomerating are combined in a single step by performing the process in a mill having positive transport capability.

Abstract: A device is disclosed for use in connecting a prosthesis to bone such as connecting an artificial tooth or dental bridge to the jaws which comprises an implant portion or screw for connection to the bone, the screw having a head and a downwardly tapered shaft, an abutment portion for connection to the prothesis, and connecting means for connecting the implant and the abutment. Preferably, the components of the invention are machined from titanium alloy.

Abstract: A data receiving system for digital data communication described which uses asynchronous sampling and lagrangian or prolate spheroidal function interpolation on the received signal. A received analog signal is first asynchronously sampled, digitized stored in a memory and then processed using interpolation technique to recover the correct symbol timing of the symbols in the digitized data. The minimum sampling rate commensurate with channel band width is used. The correct symbol timing is continuously adjusted within certain pre-determined limits of the interpolation interval using a "jumping" algorithm which permits continuous symbol tracking. The recovered symbols are then equalized to compensate for channel distortion and decoded to give the originally encoded data. When bursts of data are being transmitted the data stored in memory is replayed to ensure that all data in the data burst is used for communication and that there is no transmission overhead requiring extra symbols for synchronization.

Abstract: A method of treating wastewater containing a contaminant selected from the group consisting of heavy metal cations, tars, oils and phenols or mixtures thereof, comprising mixing said wastewater with an effective amount of desulfurization slag, the composition of said slag including calcium oxide, calcium sulfide and iron oxides, causing deposition of said contaminant from the mixture, and separating the deposit from the supernatant liquid.

Abstract: Apparatus are disclosed to scan an elongate portion of the patient. The apparatus have a low power x-ray source and imaging assembly, each having a collimating slit through which an x-ray beam is transmitted. Means are provided to move the patient relative to the x-ray source. A film pack is located in the imaging assembly and is mounted on a motor carrier to move the film pack progressively past the slit axis so as to record the image obtained. The low power x-ray beam is offset by a high speed film and an image intensifier in the imaging assembly, thereby reducing the amount of radiation subjected on the patient.

Abstract: A bed is disclosed, comprising a base having a floor and an upstanding wall extending aroung the periphery of the floor. A body of particulate fluidizable material is contained within the base. The floor has an elongate slit connectable to an air supply and a pair of inclined surfaces extending upwardly on opposite sides of the slit. Supply of air to the slit causes circulation of the particulate material along the inclined surfaces towards the slit and causes fluidization of the upper region of the base.

Abstract: The invention provides an edible fat product for incorporation into a formula suitable for feeding infants. The product includes certain fatty acids, namely, at least one of a C.sub.20 or C.sub.22, .omega.-6 fatty acid and a C.sub.20 or C.sub.22, .omega.-3 fatty acid, found to be present in human milk. These fatty acids are included in the product in certain defined amounts to avoid causing harmful effects on an infant fed on the product. The C.sub.20 or C.sub.22, .omega.-6 fatty acids, if present, are included in a total amount of about 0.13%-5.6% by weight of all fatty acids in the product. The C.sub.20 or C.sub.22, .omega.-3 fatty acids, if present, are included in a total amount of about 0.013%-3.33% by weight of all fatty acids in the product.

Abstract: A particle classifier has a uniform, laminar, classifying air stream and a duct to introduce particulate material generally perpendicular to the air stream. The particulate material is entrained in a secondary air stream that is diverted as it enters the classifying air stream by a curved surface. The curved surface produces and diverts the air stream by the Coanda effect to minimize disturbance to the classifying air and segregate the particles from the secondary air.

Abstract: Poly(methylmethacrylate) polymer particles of substantially increased average particle diameter are prepared by suspension polymerization in a medium comprising an alkane and a chlorinated hydrocarbon, e.g. carbon tetrachloride, in relative proportions chosen so as to provide buoyancy to the polymer particles so formed.

Abstract: Sleep disorders in mammals, such as insomnia and narcolepsy, are treated by administering an effective amount of ethyl 4-acetoxybutanoate, or a closely related homolog thereof.

Abstract: The invention provides a class B output stage for an amplifier, more specifically an integrated circuit amplifier for low power, low voltage application, such as a hearing aid amplifier, that is of class B type with consequent negligible quiescent power dissipation, but which avoids the input voltage deadband of conventional class B stages that results in cross-over distortion. The stage uses a bipolar transistor and a field transistor connected in series. The field effect transistor has a gate-source pinch-off voltage that is approximately equal to the base-emitter voltage of the bipolar transistor, so that they are alternately "on" as the input voltage swings over its full value. In a preferred embodiment the bipolar transistor is an npn type while the field effect transistor is a bipolar compatible p-channel junction field effect transistor (JFET) with pinch-off voltage as close as possible but just less than the base emitter voltage of the bipolar transistor.