Abstract: In a method for manufacturing a forging die with improved wear resistance, hot-work tool steel is obtained in which Al is added as a de-oxidizing agent during manufacture of the hot-work tool steel in a sufficient quantity such that it is only partially consumed during the de-oxidizing process, leaving Al in a range of greater than 0.015 weight percent after the de-oxidizing process. The forging die is shaped from the hot-work tool steel. By a subsequent nitriding process, a hardened surface is created on the forging die by heating in a nitriding atmosphere by interaction with the Al to improve a hardened surface on the hot-work forging die resulting in an improvement in wear resistance.

Abstract: An optical monitoring system comprising first and second sensor arrays interrogated via first and second optical connections from an interrogator location. The system is configured such that no wavelength is carried bi-directionally in the first and second optical connections. In typical systems the optical connections comprise trunk cables from the sensor arrays to the interrogator location.

Abstract: In a method for manufacturing a forging die with improved wear resistance, hot-work tool steel is obtained in which Al is added as a de-oxidizing agent during manufacture of the hot-work tool steel in a sufficient quantity such that it is only partially consumed during the de-oxidizing process, leaving Al in a range of greater than 0.015 weight percent after the de-oxidizing process. The forging die is shaped from the hot-work tool steel. By a subsequent nitriding process, a hardened surface is created on the forging die by heating in a nitriding atmosphere by interaction with the Al to improve a hardened surface on the hot-work forging die resulting in an improvement in wear resistance.

Abstract: An optical monitoring system comprising first and second sensor arrays interrogated via first and second optical connections from an interrogator location. The system is configured such that no wavelength is carried bi-directionally in the first and second optical connections. In typical systems the optical connections comprise trunk cables from the sensor arrays to the interrogator location.

Abstract: There is described an optical seismic cable (2) comprising a number of sensor units (5) spaced along the length of the cable and a number of connection units (4) spaced along the length of the cable, the cable further comprising a number of first optical fibers extending substantially continuously along the cable from one connection unit to the next, and a number of second optical fibers which each extend part-way along the cable between adjacent connection units, and wherein at each connection unit at least one first optical fiber is joined to a second optical fiber, and wherein at the sensor units sensors are joined to said second optical fibers.

Abstract: An optical sensing system, comprising a plurality of optical sensors (206 . . . 209), first (203 . . . 205) and second (215, 216) input trees, and first (210 . . . 212) and second (219, 220) output trees. The first and second input trees are configured to direct respective optical signals from a first (202) and a second (214) input to each of the sensors, and the first and second output trees are configured to direct optical signals from each of the sensors (206 . . . 209) to a first (213) and a second (221) optical output. The first and second input and/or output trees are configured to direct signals of particular wavelengths (A1 . . . D-1, A2 . . . D2) from particular sensors to the first and second input and/or output, respectively. A redundant connection system thus provided allows continued operation in the event of a fibre or cable break (300).

Abstract: A method for heat treatment of steel and a system thereof is provided. First the steel is austenitized at a suitable temperature and then the temperature is rapidly brought down to the austempering temperature. Here the cyclic austempering is carried out between two austempering temperatures by modulating the temperature with controlled heating and cooling and the controlled temperature modulation is obtained by controlling the temperature-time profile in a batch furnace or by controlling the zone temperatures in a continuous furnace. This method of cyclic austempering reduces the austempering time, reduces the energy consumption and emissions, enhances the productivity and reduces the process cost.

Abstract: There is described an optical seismic cable (2) comprising a number of sensor units (5) spaced along the length of the cable and a number of connection units (4) spaced along the length of the cable, the cable further comprising a number of first optical fibres extending substantially continuously along the cable from one connection unit to the next, and a number of second optical fibres which each extend part-way along the cable between adjacent connection units, and wherein at each connection unit at least one first optical fibre is joined to a second optical fibre, and wherein at the sensor units sensors are joined to said second optical fibres.

Abstract: A method for heat treatment of steel and a system thereof is provided. First the steel is austenitized at a suitable temperature and then the temperature is rapidly brought down to the austempering temperature. Here the cyclic austempering is carried out between two austempering temperatures by modulating the temperature with controlled heating and cooling and the controlled temperature modulation is obtained by controlling the temperature-time profile in a batch furnace or by controlling the zone temperatures in a continuous furnace. This method of cyclic austempering reduces the austempering time, reduces the energy consumption and emissions, enhances the productivity and reduces the process cost.

Abstract: A three wheeled baby stroller is provided with a single steerable rear wheel. The stroller preferably has the three wheels positioned to form an equilateral triangle, resulting in a highly maneuverable stroller. The stroller has a minimized turning swath and is easily steered. The stroller has a simple and relatively lightweight design. The seat for the infant is positioned relatively low to the ground to increase stability.

Abstract: A fibre-optic surveillance system (10) includes a fibre-optic sensor (15) comprising a serial array (15) of fibre-optic point-sensors (16), successive point-sensors being linked by a distributed fibre-optic sensor (18). The system allows the location of intruder events along the sensor to be determined, and provides a reduction in the incidence of false-alarms compared to prior art systems.

Abstract: A vibration sensing device, package and system and a method of manufacturing a vibration sensing device are disclosed. The vibration sensing device comprises a body whose geometry is such that it exhibits flextensional properties.

Abstract: An optical sensor assembly comprising a plurality of optical fibre sensor coils optically coupled by optical fibre; and an elongate support element, on which said plurality of optical fibre sensor coils and optically coupling optical fibre are mounted is disclosed. The support element has an elastic limit such that when said support element is bent from the elongate axis, the optical fibre fracture limit is reached before the elastic limit is reached. An array of these optical sensor assemblies, the mandrel on which the sensing coils are mounted and their method of manufacture are also disclosed.

Abstract: Attached to a cable having a central strength member is an optical sensor assembly. The sensor assembly comprises a coupler and an optical fibre coil. The coupler is attached to the central member of the cable at a position where outer layers of the cable been removed. A first terminal of the coupler is connected to an optical fibre traveling along the cable in a fibre conduit external to the central strength member. A second terminal of the coupler is connected to a first end of the coil and a third terminal of the coupler is connected to an optical fibre a mirrored end. The coil is supported about a tubular mandrel, which mandrel fits over the cable. The other end of the coil is attached to the fibre in the cable. The mandrel is located about the cable at a position covering the coupler and the part of the cable where the outer layers are removed. The whole assembly is covered with a waterproof layer sealing it to the cable.

Abstract: The present invention provides an attitude sensing device and method for determining an attitude of a reference axis of a package containing a fibre optic sensor sensor. The attitude sensing device comprises an electromechanical attitude sensor for generating an electrical signal indicative of the attitude sensor, and converter logic for converting the electrical signal into a stimulus signal. A local power source is preferably provided for the electromechanical attitude sensor in the converter logic. The stimulus signal is such that the fibre optical sensor is responsive to the stimulus signal to cause a variation in at least one predetermined property of an optical signal transmitted through the fibre optic sensor, the attitude of the reference axis being determinable from the variation of the predetermined property.

Abstract: A vibration sensing device, an acceleration sensing system and a method of manufacturing a vibration sensing device wherein the vibration sensing device comprises a flexible disk that is mounted symmetrically about a radial plane and has a mass located on the disk substantially symmetrical about this radial plane which exerts a force that is greater towards the edge than it is towards the centre of the disk. The vibration sensing device is sensitive to on-axis signals and insensitive to cross axis signals.

Abstract: Musical instrument sound detection is achieved using a fibre optic acoustic sensor that is sensitive to sound generated by a musical instrument. Sound waves falling on the acoustic sensor cause at least one property of electromagnetic radiation transmitted through the fibre optic to vary. This variation is indicative of the sound generated by the musical instrument and can be detected by an electromagnetic radiation detector.

Abstract: A gain compensation loop suitable for a quadrature receiver comprises a signal strength comparator having in-phase and quadrature signals fed to respective inputs of the signal strength comparator. The signal strength comparator outputs a signal which represents the difference in strength between the in-phase and quadrature signals. The signal output from the signal strength comparator is input to a gain adjuster which adjusts the gain of the in-phase or quadrature signal in accordance with the signal from the signal strength comparator to bring the in-phase and quadrature signals towards the same strength.

Abstract: A radio telephone has an array of manually operable switches mounted on a respective support. A processing circuit processes signals received via said switches and said support supplies signals to said processing device over a single transmission line. The processing device is arranged to determine an analogue characteristic of a signal received from the support via said transmission line in order to determine which of said manually operable keys has been manually operated. An analogue-to-digital converter can be used to measure voltage values identifying key selection or a timer can be used to measure capacitor charging or discharging.