Abstract: The alignment of railway tracks may be monitored using an accelerometer (36) mounted on a bogie (24) of a railway vehicle to detect lateral accelerations, and a displacement transducer (38) to monitor the lateral displacements of a wheelset (27) relative to the bogie. The acceleration signals are digitised, and processed corresponding to double integration, so as to deduce the lateral displacements of the bogie, and in conjunction with the signals from the displacement transducer hence to determine the effective lateral displacements of the track. This can provide a more useful indication of the lateral positions of the rails than measurements of the gauge faces. Such equipment (16) may be installed in a service vehicle, and operate automatically, downloading resulting data to a remote base station at regular intervals.

Abstract: In a railway line, thermally-induced stresses are a factor for both rail breaks and rail buckling. These stresses are in the longitudinal direction. A nondestructive measuring technique enables the residual stress in a rail to be determined, and hence the thermally-induced stress. An electromagnetic probe is used to measure the stresses in the rail web in the vertical direction, and in the direction parallel to the longitudinal axis. The residual stress in the longitudinal direction can be deduced from the measured stress in the vertical direction; hence the thermally-induced stress can be determined.

Abstract: The onset of rolling contact fatigue in an object may be detected by measuring the residual stresses in the surface of the object, and monitoring changes in their magnitude or their direction. The values of residual stresses in the surface are those averaged over a depth that may be in the range say 0.1 mm to 8.0 mm, for example about 2.5 mm. For ferromagnetic objects such as rails, the method may utilize an electromagnetic probe. Prior to rolling contact fatigue the surface stresses are compressive, and the onset of rolling contact fatigue may be characterized by a marked decrease of the stress in the generally transverse direction.

Abstract: A gamma radiation source comprising selenium-75 or a precursor therefore, wherein the selenium is provided in the form of one or more thermally stable compounds, alloys, or mixed metal phases.

Abstract: The variation in properties of a ferromagnetic material with depth below the surface is assessed in a nondestructive fashion using a probe that incorporates an electromagnet. An alternating magnetic field is generated in the electromagnet and so in the object, and a magnetic sensor is arranged to sense a magnetic field due to the electromagnet. Signals from the magnetic sensor are analysed into an in-phase component and a quadrature component, and these are mapped directly into material property and lift-off components; this analysis enables accurate measurements of material property (such as stress) to be distinguished from changes in lift-off. The measurements are repeated for at least five different frequencies of the alternating magnetic field; and the measurements at different frequencies are deconvolved assuming a functional form for the variation of material property with depth, the function having no more than five unknown constants. The stress at depths for example in the range 0.5 mm to 5.

Abstract: A break in a rail, where two rails (12, 13) extend parallel to each other along a railway line, is detected by connecting the two rails together electrically with two electrical connections (16, 18) at opposite ends of a section of the line, causing electrical currents to flow in parallel along the two rails from a current source (22), and detecting (24) the currents flowing in each of the rails (12, 13). From the two values of current one can find it there is a break in one of the rails (12, 13). The currents may be measured in one of the connections (16). The current source (22) may be DC or low frequency AC, or a coded pulse sequence.

Abstract: A radioactive static eliminator gun has a cartridge (7) connected to a high pressure air supply (8). Within the cartridge (7) a radioactive source (6) which generates alpha particles is located coaxially along the central longituidinal axis. The alpha particles collide with the high pressure air stream passing through the cartridge thereby generating ions. With this arrangement the ion concentration is greatest at the core of the air stream which ensures that the greatest number of ions is delivered to the surface requiring static elimination. The radioactive static eliminator gun provides improved efficiency in removing static an is particularly suited to use in paint spraying of metal surfaces where the electrostatic forces at the surface of the metal may not be strong enough to attract ions in the air stream emerging from the gun.

Abstract: Fluids in a vessel are subjected to a high ultrasonic intensity, by means of several ultrasonic transducers attached to a wall of the vessel, each transducer (14) radiating no more than 3 W/cm2, the transducers being sufficiently close to each other, and the number of transducers being sufficiently high, that the power dissipation within the vessel is at least 25 W/litre. The number of transducers, the power of the transducers, and the volume of the vessel may be such that the power density is between 40 and 80 W/litre. The vessel may be double walled, and the space between the two walls be filled by a low attenuation buffer liquid (36) whose cavitation threshold is above that of the liquid being treated.

Abstract: A random number generator has a random event source, a random event detector, and a counter for counting the number of pulses generated by the detector for a predetermined length of time. Two memories are provided in which are stored successive sets of counts and a controller compares the sets to determine whether one or both of the sets counted one or more events. Where both sets have one or more events, no output is generated, and where both sets have no events, no output is generated. However, where one set has one or more events and the other set has no events, then a binary number is output in dependence on which of the two sets recorded events. This random number generator has the advantage that the probability of counting no events does not have to be exactly equal to the probability of counting one or more events while still ensuring truly random results.

Abstract: For monitoring railway tracks on a frequent basis, instrumentation packages are installed in service vehicles (18), for example in passenger carriages. The instrumentation package (16) comprises sensors (35, 36, 42) mounted on a bogie (24) of the vehicle (18), which provide data to a computer (40). The computer (40) processes the data to characterise the track quality, and stores the results tagged with positional information. At intervals these stored results are automatically transferred by radio to a remote base station (12). An operator at the base station can monitor the track quality daily, and hence advise on cost-effective maintenance schedules.

Abstract: If the wheel/rail adhesion for a railway vehicle is insufficient then the wheels may slip when braking. If slipping is detected, a control system may reduce the brake pressure to permit a controlled level of slip and so to optimize the braking force for the available adhesion. By determining the pressure supplied to the brake cylinder, a signal may be obtained which indicates the value of the adhesion. Alternatively the adhesion may be monitored by detecting any discrepancy between the braking deceleration demanded by the driver and the observed deceleration. The adhesion signal may activate a warning. It may also be used to adjust the rate at which sand is supplied by a sander to the wheel/rail interface. The rate at which sand is supplied may also be adjusted in accordance with other parameters such as the train speed.

Abstract: During use, a wheel of a railway vehicle may become out of round, which will be detrimental to both the vehicle suspension and the railway track. The shape of such a wheel may be monitored to detect any such out of roundness, while the wheel is rolling, by measuring how far the flange of the wheel projects below the upper surface of the rail. This may be achieved by mounting a rigid bar (24) alongside the rail (10), the bar (24) being supported resiliently so as to be depressed by a flange of a wheel (40), and by measuring the vertical displacement of the bar. The bar (24) may be supported by a plurality of flat leaf springs (26), which are inclined to the horizontal at for example 30°. This ensures that the bar (24) remains substantially parallel to the top surface of the rail (10) when depressed by the flange of a wheel (40).

Abstract: A method for configuring and executing a software application with a client user interface, the method including the steps of accessing a master configuration file containing an array of configuration variables controlling the execution of the software application, preselecting a subset of configuration variables from the array of configuration variables contained in the master configuration file, generating the client user interface to modify only the subset of configuration variables, transmitting the client user interface to a client computer, receiving the subset of configuration variables as modified on the client computer, applying the subset of configuration variables against the master configuration file, executing the software application in accordance with the master configuration file on a computational server, the execution of the software application producing an output result, and transmitting the output result to the client computer.

Abstract: A femoral component as herein before described for an artificial hip joint made out of an alloy containing titanium, wherein at least a major load bearing portion of which has been subjected to bombardment by a beam of nitrogen or other light ions having energies in the range of 10 Kev to 200 Kev until a surface fluence of between 1 and 8×1017 ions/cm2 has been implanted. An apparatus for processing such components is described also.

Abstract: A plasma enhanced gas reactor including a reaction chamber having a pair of field-enhancing electrodes each of which has an axial passage through it by one of which a reactant gas is admitted to the reaction chamber, and by the other of which reaction products are removed from the reaction chamber.

Abstract: A plate (12) or pipe wall is inspected by coupling an ultrasonic transducer (14, 16) to its surface so as to generate a compression wave or lateral wave (26) along the surface and a shear wave or head wave (28) along the surface and a shear wave or head wave (28) at the shear-compression critical angle (.theta..sub.c) The same transducer (14, 16), or an additional transducer (15, 16) also coupled to the surface, detects a series of ultrasonic peaks corresponding to each generated ultrasonic pulse. Each such detected peak corresponds to ultrasonic energy traveling, partly as lateral waves (26, 32) on one surface or the other, and partly as head waves (28, 30) crossing a certain number of times between the surfaces. The transducers (14, 15) may be over 0.5 m apart, and substantially all the intervening parts of the plate (12) are inspected.

Abstract: An improved polymer film material for the packaging of perishable foodstuffs, wherein the surface structure of the polymer is altered by means of an ion bombardment process so as to reduce the rates of transport of oxygen and water vapor through the polymer material wherein the polymer film material is produced by subjecting at least one surface of the film to ion bombardment with ions selected from the group consisting of hydrogen, carbon, nitrogen, helium, and argon at energies of 30-80 KeV and ion doses in the range of 10.sup.12 to 10.sup.18 ions/cm.sup.2.

Abstract: A method of, and apparatus for, preventing the formation of deposits on surfaces downstream of a mixer in which possibly supersaturated mixtures issuing from the mixer are surrounded by a sheath of unsaturated solution. In an arrangement described, the sheath of unsaturated mixture is obtained by bleeding off some of the mixture issuing from the mixer sufficiently downstream of the mixer definitely to be unsaturated and returning this portion of the mixture to surround that issuing from the mixer.

Abstract: A polymeric chain consisting primarily of vinylidene fluoride, onto which is grafted a mono-unsaturated carboxylic acid, ester, or amide, for example acrylic acid, may be combined with a lithium salt and a solvent to form an electrolyte material. This may be used as electrolyte in a lithium cell, or may be combined with an insertion material to make a composite electrode for such a cell. The electrolyte, and so also the composite electrode incorporating this electrolyte, adheres well to a metal current collector.

Abstract: In a magnetically insulated line oscillator device having a cathode 11, a surrounding slow wave structure 15 has a tapered configuration so that the effective cavity depth in the slow wave structure 15 progressively diminishes along a part of the length of the device towards the power output end of the device.