Abstract: A two-phase switched reluctance motor comprises a rotor without windings, a stator having windings, and an electronic control circuit for controlling the current in the windings to effect rotation of the rotor. The control circuit includes a capacitance bridge defining a floating point to which one end of each of the windings is coupled to form a resonance circuit. Switching transistors are connected to the windings and are switched in synchronism with rotation of the rotor so as to produce current pulses which are limited by the build-up of voltage at the floating point of the capacitance bridge. This ensures that the current in the windings returns naturally to zero at the end of each excitation pulse, thus providing more efficient power operation and reducing the acoustic noise of the machine.

Abstract: A catalyst is provided for addition polymerization of olefinically unsaturated monomers comprising a first compound MY, wherein M is a transition metal in a low valency state or a transition metal in a low valency state coordinated to at least one coordinating non-charged ligand, Y is a monovalent, divalent or polyvalent counterion; an initiator compound comprising a homolytically breakable bond with a halogen atom; and an organodiimine, where at least one of the nitrogens of the diimine is not part of an aromatic ring.

Abstract: An electrical machine comprises a four-pole stator 2 provided with a field winding 10 and an armature winding 11, each of the windings 10, 11 being split into two coils 22, 23 or 24, 25 closely coupled and wound so that diametrically opposite portions of both coils are disposed within diametrically opposite stator slots. A two-pole rotor (not shown) without windings is rotatable within the stator 2, and a circuit is provided for energising the armature coils 24 and 25 when direct current is supplied to terminals 26 and 27 of the circuit. Switches 28 and 29 in series with the coils 24 and 25 are switched alternately to effect alternate energisation of the coils 24 and 25 so as to generate, as a result of the opposite winding of the coils, magnetomotive forces in opposite directions.

Abstract: The invention discloses methods of controlling one or more genes in plants. The genes may be exogenous genes and produce a desired phenotypic trait in the plants produced. The genes are operatively linked to a heterologous upstream activating sequence (UAS) recognition site, which is activatable by a transactivating protein. The genes linked to the UAS sequence, and nucleic acid encoding for the transactivating protein may originally be in separate transgenic plants, one of which fertilizes the other to produce reproductive material, such as seed, which may be grown into plants expressing the desired phenotype. The desired phenotype may be herbicide resistance or the production of a polyhydroxyalkanoate, such as polyhydroxybutyrate.

Abstract: A gas-sensing semiconductor device 1 is fabricated on a silicon substrate 2 having a thin silicon oxide insulating layer 3 on one side and a thin silicon layer 4 on top of the insulating layer 3 using CMOS SOI technology. The silicon layer 4 may be in the form of an island surrounded by a silicon oxide insulating barrier layer 4 formed by the known LOCOS oxidation technique, although other lateral isolation techniques may also be used. The device 1 includes at least one sensing area provided with a gas-sensitive layer 18, a MOSFET heater 6 for heating the gas-sensitive layer 18 to promote gas reaction with the gas-sensitive layer 18 and a sensor 16, which may be in the form of a chemoresistor, for providing an electrical output indicative of gas reaction with the gas-sensitive layer 18. As one of the final fabrication steps, the substrate 2 is back-etched so as to form a thin membrane 20 in the sensing area. Such a device can be produced at low cost using conventional CMOS SOI technology.

Abstract: A switched reluctance electrical machine system including a switched reluctance machine, a rechargeable DC energy store and principle voltage terminals connectable to an external power source. The switched reluctance machine comprises a rotor, a stator and windings wherein the windings include at least two closely-coupled coils and a power converter for controlling current flow in the windings. The power converter has first and second circuits. The first circuit contains one of the closely-coupled coils and the principle voltage terminals while the second circuit contains the other of the closely-coupled coils and the energy store. A first switching arrangement is connected in series with the coils in the first circuit and a second switching arrangement is connected in series with the coils in the second circuit.

Abstract: A non-contact apparatus for monitoring the contents of a container, especially but not exclusively for quality control monitoring purposes associated with high speed packaging processes, comprises a non-contact ultrasound generation member, adapted so as to generate an ultrasound signal within the container (1). A non-contact detection scheme is employed to enable the contents of the container to be monitored by analysing ultrasound signals that have propagated through or round the container (1) either transmitted through or reflected from the containers contents. In use, the apparatus may be adapted to provide information about container fill level (h) or the presence or absence of an insert (14) such as a head forming device by analysing the measured signal profiles generated by a ultrasound detection member (3).

Abstract: A thermal compressor (10) comprises two adsorbent beds (11, 12) each with an associated thermal management system (14). The thermal management systems (14) are identical and consist of a circulating supply of a control fluid which passes through the adsorbent bed, a pump (15), a heat exchanger (16) and an inert bed (17, 18). Heat removed from the adsorbent beds (11, 12) by the control fluid is supplied to the inert beds (17, 18) and is store to be subsequently regenerated to heat the adsorbent beds (11, 12) in a later half of the operating cycle of the thermal compressor (10). The thermal compressor (10) is energy efficient by virtue of the heat recycling which is performed.

Abstract: A DNA sequence encoding the CarR gene product or a homologue or variant thereof which, on expression in bacteria, is capable of activating gene expression, especially of a gene coding for a carbapenem antibiotic. A polypeptide coded for by such DNA.

Abstract: The invention discloses methods of controlling one or more genes in plants. The genes may be exogenous genes and produce a desired phenotypic trait in the plants produced. The genes are operatively linked to a heterologous upstream activating sequence (UAS) recognition site, which is activatable by a transactivating protein, such as GAL4. The genes linked to the UAS sequence, and nucleic acid encoding for the transactivating protein may originally be in separate transgenic plants, one of which fertilises the other to produce reproductive material, such as seed, which may be grown into plants expressing the desired phenotype. The desired phenotype may be herbicide resistance or the production of a polyhydroxyalkanoate, such as polyhydroxybutyrate.

Abstract: A method of driving an electric motor having at least one coil winding comprising using a switching operation when the current in the winding is to be switched from a first state to a second state. The switching operation has at least first and second switching steps, the interval between which is approximately equal to half the period of a dominant frequency of vibration of the motor (or to an integral multiple of the period plus a half). This reduces vibrations causing acoustic noise, enabling the motor to be operated more quietly. One or more intermediate steps may be included in the switching operation.

Abstract: An electromagnetic acoustic transducer for generating ultrasound waves in an electrically conducting sample comprises a magnetic element for producing a static magnetic field, and a coil through which brief current pulses are passed to create a dynamic magnetic field, the interaction between the fields and the sample generating ultrasound waves. The current pulses are produced by an input circuit, and their characteristics are arranged so that the frequency content of the ultrasound generated is broadband. Output pulses produced as a result of the input pulses are then also brief (substantially the same duration as the input pulses) so that accurate measurement of the interval between one output pulse and the next is relatively easy. The transducer can therefore be used to measure accurately the thickness of very thin samples, and to detect near surface defects. The generating transducer may also be used for detection of the output pulses, or a similar but separate detecting transducer may be used.

Abstract: An apparatus for inspecting single crystal specimens comprises an x-ray generator which supplies x-rays to a collimator. The collimator has a matrix of apertures to produce a plurality of parallel x-ray beams which are directed onto a surface of the specimen. An x-ray detector detects the x-ray beams diffracted from the surface of the specimen, corresponding to each of the parallel x-ray beams. At each symmetry pole of an overall Laue pattern an accurately predictable pattern of spots is produced on the x-ray detector, if the orientation and shape of the specimen crystal is known. Each spot corresponds to where one of the diffracted beams strikes the detector. A disarrangement of one or more of the spots indicates a difference in crystal orientation.