Abstract: There is a described a method of certifying compliance with a designated process defined by a plurality of rules which are specified in a public template, wherein at least one rule associated with a process includes a certification requirement which requires compliance with that rule to be certified by a rule certifying authority. A processing apparatus operating in a secure environment receives rule compliance data and checks the received rule compliance data to verify that any certification requirement has been satisfied. If the processing apparatus confirms that all the rules specified in the public template are satisfied, then the processing apparatus issues a process compliance certificate which is digitally signed by the process certifying authority.

Abstract: A position determining system in which a mobile tag having an unknown position is tracked in space over time. In use, the mobile tag either transmits or receives signals including a pair of tones at different frequencies from a number of base stations having known locations. The phase of each of the received signals is then measured and the measured phases are then passed to a processing unit which determines the position of the tag at the time of the transmission of the signals on the basis of the difference between the measured phases of the two tones. In one embodiment, this system is combined with a conventional phase-based position measurement which is derived from phase measurements of similar tones transmitted between the mobile tag and different base stations.

Abstract: A man-machine interface is provided for a domestic appliance in which remotely sensed buttons, slider bars, marker pucks and a knob are used. The sensing coils for remotely sensing the positions of the buttons, slider bars, marker pucks and the knob are formed on a printed circuit board which is located behind a sealed surface such that there is no risk of contaminants accessing the printed circuit board.

Abstract: A signalling system is provided which can be used to update the prices of goods which are electronically displayed on supermarket shelves (1). The signalling system comprises a first signalling device having an input terminal for receiving electrical message data received from a central computer system (5), a spread spectrum encoder for encoding the received message data and an electroacoustic converter (11) for converting the encoded data into corresponding acoustic signals and for transmitting the acoustic signals into a transmission medium. The signalling system also comprises a second signalling device (3) having means for receiving acoustic signals from said transmission medium and for converting the received acoustic signals into corrresponding electrical signals, a spread spectrum decoder for decoding the received signals and a message regenerator for regenerating the message data transmitted by the first signalling device from the signals output by the decoder.

Abstract: A check weighing system is provided which can check weigh samples (1) on a production line. The check weighing system comprises a magnet (13) for creating a static magnetic field over an interrogation zone for creating a net magnetisation within a sample (1) located within the interrogation zone and an RF coil for applying an alternating magnetic field over the interrogation zone for causing excitation of the sample (1) within the interrogation zone according to the principles of NMR. The check weighing system also comprises a sensor for sensing the energy emitted as the sample relaxes back to an equilibrium state after excitation as the samples pass through the interrogation zone on a conveyor belt (9) forming part of the production line.

Abstract: The present invention provides a position sensor which is suitable for use in a piston and cylinder assembly. The position sensor includes a movable field modifying member which is operable to vary the inductance of a sensor winding, whereby the position of the field modifying member relative to the sensor winding can be determined by monitoring the inductance of the sensor winding. The position sensor also includes a compensation winding which is arranged to have a common coupling with the field modifying member whereby a signal output from the compensation winding can be used to compensate for variations in the signal level output by the sensor winding caused by, for example, temperature variations of the system.

Abstract: An anti-counterfeiting device for application to or association with consumer goods to give an indication of authenticity comprises: a substrate (10); a latent image (11) formed on the substrate that becomes visible upon exposure to oxygen; an oxygen-impermeable layer (12) covering the latent image, and means to break the oxygen-impermeable layer. The latent image is preferably formed by printing an oxygen-sensitive colouring material on to the substrate.

Abstract: A linear position sensor is provided which employs phase quadrature sensor windings, an excitation winding and a resonator. When an excitation current is applied to the excitation winding, it causes the resonator to resonate which in turn induces signals in the sensor windings. The sensor windings are spatially arranged so that the electromagnetic coupling between them and the resonator varies with the position of the resonator. The excitation windings, phase quadrature windings and resonant circuit are arranged so that the magnetic fields involved in the operation of the position sensor are substantially parallel to each other and the direction of movement of the resonator. Consequently, the effect of rotation of the resonator or lateral movement of it relative to the excitation and phase quadrature windings is alleviated.

Abstract: Intracellular material is released from bacterial, yeast, plant, animal, insect or human cells by the application of a low voltage such as 1 to 10 V to a suspension containing the cells. The conditions may be selected such that DNA released from the cells is electrochemically denatured so as to be available for use in an amplification procedure.

Abstract: Intracellular material is released from bacterial, yeast, plant, animal, insect or human cells by the application of a low voltage such as 1 to 10 V to a suspension containing the cells. The conditions may be selected such that DNA released from the cells is electrochemically denatured so as to be available for use in an amplification procedure.

Abstract: Particles are separated according to their dielectrophoretic characteristics and electrorotation characteristics by the use of a travelling wave separation in which they flow from a departure point at an inlet (18) towards at least two destinations at outlets (16, 20) and are deflected toward one or other outlet according to their characteristics by a travelling wave field set up on an array of electrodes, each electrode running generally in the direction of flow.

Abstract: This invention provides methods for denaturing nucleic acids. The methods involve contacting a solution comprising double stranded nucleic acid with a surface having denaturation activity sufficient to produce denaturation within a period of not more than one hour.

Abstract: A position encoder is provided for indicating the relative position between first and second relatively movable members. One of the members carries a multi-pole magnetic scale which generates a magnetic field whose magnitude and direction vary with position and the other member carries at least one sense conductor. A saturable magnetic element is located in the positionally varying magnetic field of the magnetic scale and an excitation winding is provided which, when energized, generates a magnetic filed which interacts with the positionally varying magnetic field to cause different portions of the saturable magnetic element to saturate and desaturate at different times. The arrangement of the sense conductor is such that as the magnetic element is driven into and out of saturation, it outputs a signal which is indicative of the position of the magnetic scale relative to the sense conductor.

Abstract: Travelling wave particle separation apparatus is provided having a flat spiral of electrodes (1,2,3,4) or a helix of similar electrodes on a cylindrical former. Only four electrical connections need to be made.

Abstract: Particles are subjected to travelling wave field migration (TWFM) to migrate the particles over an array of microelectrodes. Altered particles are produced by treating original particles in such a way so as to alter their TWFM characteristics and the altered TWFM characteristics are employed for analysis and/or separation of the altered particles. The particles may be cells, bacteria, viruses, biomolecules or plastics microspheres. They may be altered by binding to a ligand such as a metal microparticle via a selective linking moiety such as an antibody/antigen or oligonucleic acid, or be physical or chemical treatments.

Abstract: A process is described for denaturing native double-stranded nucleic acid material into its individual strands in an electrochemical cell. The process disclosed is an electrical treatment of the nucleic acid with a voltage applied to the nucleic acid material by an electrode. The process may also employ a promoter compound such as methyl viologen to speed denaturation. The process may be used in the detection of nucleic acid by hybridizing with a labelled probe or in the amplification of DNA by a polymerase chain reaction or ligase chain reaction.

Abstract: In a linear position encoder, a support is provided upon which a pair of phase quadrature windings are mounted. The windings are arranged to have a sinusoidal magnetic sensitivity characteristic along the length of the support. Mounted on a movable element there is a resonant circuit including a coil and capacitor that can magnetically couple with the windings. When the circuit is excited, it induces currents in the windings that are dependent upon the position of the circuit within a period T.sub.s of the windings. An excitation and processing unit is provided to energize the circuit and to process the signals induced in the windings. The encoder may in a variation, measure rotational or radial position instead of translation.

Abstract: An apparatus for indicating the angular position of a rotatable member includes a drive coil with its axis corresponding to the axis of rotation of the rotatable member. A coil is wound around the rotatable member, and a capacitor is provided in the coil to form an LC resonant circuit. The coil on the rotatable member is wound so that application of an alternating magnetic field to the drive coil induces a resonance in the LC circuit which is constant for all angular positions of the rotatable member. Pick-up coils are provided such that the planes of these coils and the drive coil are orthogonal. The resonance of the LC circuit produces signals in the output coils which depend upon the angular position of the rotatable member. The signals may be processed to determine that angular position, and the processing is simplified with this arrangement of output coils since the signals produced therein are quadrature signals.

Abstract: Apparatus for indicating the value of a variable comprising first and second members moveable relative to each other as a function of said variable, a plurality of elements of a first type on one of said members, at least one element of a second type on the other of said members, one of said types being magnetostrictive and the other being operative to produce a magnetic bias field, said elements being arranged so that as said first and second members move relative to each other different ones of said plurality of elements of said first type magnetically interact with said at least one element of said second type such that, for different positions of said members, said interaction causes magnetostrictive resonance at different frequencies in response to an alternating interrogating magnetic field at said different frequencies.

Abstract: A process is described for denaturing native double-stranded nucleic acid material into its individual strands in an electrochemical cell. The process is an electrical treatment of the nucleic acid with a voltage applied to the nucleic acid material by an electrode. The process employs a promoter which is an inorganic multivalent cation such as magnesium ions to speed denaturation. The process may be used in the detection of nucleic acid by hybridrising with a labelled probe or in the amplification of DNA by a polymerase chain reaction or ligase chain reaction.