Abstract: The invention relates to a thermal infrared transparent polymer film suitable for use in an identification device, said film comprising an infrared transparent polymer matrix with a pigment dispersed therein, wherein the thickness of the polymer film is greater than 30 micron and wherein the polymer film has an average transmission in the thermal infrared of greater than or equal to 0.5. Preferably, the pigment comprises an inorganic material. There is further provided a thin film, thermally reflective material (20) comprising the afore-mentioned infrared transparent film (21) and an infrared reflective layer provided on one surface thereof (22).

Abstract: Some embodiments are directed to a controlled differential adapted to couple two shafts and steer input, such as those provided in a drive configuration for a skid steered vehicle, the controlled differential including a pair of planet carriers arranged to turn with respective shafts; a pair of ring gears interconnected by a cross-shaft such that the ring gears rotate in common; planet gears and a pair of sun gears, the sun gears being coupled to at least one steer motor to enable rotation of the sun gears in mutually opposite senses upon input from the steer motor.

Abstract: Some embodiments are directed to methods of detecting a target that include: receiving signals reflected from a target of interest, the signals having a bandwidth large enough to provide a plurality of range cells along an expected target, and processing the received signal(s) by (i) determining the phases of contiguous groups of range cells, the group size selected to approximate to sizes of targets of interest, (ii) phase-shifting the returns within a group to increase constructive interference and thereby signal power; and (iii) combining the phase shifted returns to produce phase-adjusted combined returns, and performing a detection on those combined returns. Some embodiments may provide enhanced target detection capabilities. The process may be repeated for different potential target sizes, and may be performed either on real time data, or off-line on recorded data, and is applicable to both radar and sonar.

Abstract: A one-way valve for use in the inhalation and/or exhalation flowpath of respiratory protection equipment comprises a housing 1 defining a conduit and a circumferential array of three flexible flaps 2 each extending inwards from the conduit wall and in the direction away from the inlet end I of the valve. Under a pressure differential in the opening direction of the valve each flap is adapted to flex outwards towards the conduit wall and under a reverse pressure differential the free edge 5,5 of each flap is adapted to press in sealing contact with respective portions of the free edges of the neighboring flaps.

Abstract: This invention relates to a novel curing method of oligomers, using metal triflates, and particularly to the curing of hydroxyl terminated elastomers to achieve crosslinked polymers. The method finds particular use as an alternative cure methodology to replace isocyanate curing. There is further provided a cured and crosslinked polymer binder, which is particularly suitable and compatible for use with energetic materials.

Abstract: This invention relates to the field of an electromagnetic (EM) field absorbing composition, in particular, those capable of providing absorbance in the frequency of commercial radar. The composition finds particular use as a radar absorbing coating for wind turbines, in particular for use in onshore and offshore environments. There are further provided coated surfaces comprising the composition, methods of absorbing EM radiation, and methods of use of such a composition, such that a surface coated in the composition is capable of absorbing EM radiation. There is provided an electromagnetic radiation absorbing composition comprising elongate carbon elements with an average longest dimension in the range of 50 to 1 000 microns, with a thickness in the range of 1 to 15 microns and present in the range of from 0.5 to 20 volume % dried, in a non conductive binder.

Abstract: An electrothermal heater mat for anti-icing or de-icing of a helicopter rotor blade or other aerodynamic surface comprises a substrate, such as a flexible polyimide sheet, bearing tracks of a material of selected electrical resistivity, these tracks being formed by printing onto the substrate with a thermosetting ink loaded with electrically conductive (e.g. carbon) particles. Electrical bus bars/terminals for the supply of electrical energy to the resistive tracks may also be printed, using an ink loaded with particles of higher conductivity material such as copper or silver.

Abstract: A filter for removing coherent radiation from a source in a field of view, substantially independent of the size of the source, comprises a first reticle 22 located in the path of received light 21, a first lens 23 producing an optical transform of the first reticle 22 at a second reticle 24 located in the image plane of the first lens 23, a second lens 25 producing an optical transform of the second reticle 24 and a third reticle 26 located in the image plane of the second lens 25. The arrangement is such that the spatial transmittance of the third reticle 26 is selected to block at least part of the diffracted image of the first reticle 22 produced in the image plane of the second lens 25 and characteristic of the coherent radiation. Preferably the optical transforms are Fourier Transforms. A monochromatic coherent source in the field of view produces a pattern of diffracted energy in the image plane of the second lens which is independent of the size of the source.

Abstract: Some embodiments are directed to a gearbox including first and second rotational members, the first rotational member having a shaft portion extending away from the gearbox, the first rotational member carrying one or more projections, the second rotational member carrying one or more complementary projections, the projections carried by the first rotational member being configured to be drivingly engaged with the complementary projections carried by the second rotational member to transmit torque in a first torque connection but not in a torque connection that is opposed to the first torque connection. The gearbox further includes a one way clutch adapted such that the first and second rotational members can be drivingly engaged to transmit torque in a second torque connection, wherein the second torque connection is opposed to the first torque connection.

Abstract: A terrain disruption device includes an air or gas flow generation device mounted on a remote operated vehicle having an extendible arm, wherein the air or gas flow generation device includes an elongate (optionally detachable) ducting arrangement to direct the air or gas flow and an optional nozzle. The air or gas flow generation device and/or the elongate ducting arrangement may be mounted on the extendible arm. Preferably, the air or gas flow generation device is powered by a fan, more preferably an electric ducted fan.

Abstract: A respirator has one or more electrodes of e.g. conductive elastomer disposed on the surface of a face sealing member opposite to the surface which seals against the user's face. In use the integrity of the seal formed between the sealing member and the user's face is monitored by monitoring the electrical capacitance across that member between the electrode(s) and the user's face.

Abstract: A method for mitigating interference in a receiver, where the received signal is transmitted in a fashion having equivalent information content in at least two distinct bands. The method compares mean power per unit bandwidth in suitably normalised sidebands and sets a rejection threshold based upon the measured levels. Bands above the threshold may be rejected from further processing. The bands may include sidebands produced by a modulation process that produces sidebands having the same informational content. The threshold may be set relative to the band having the lowest mean power per unit bandwidth or according to some other function of the bands. Also extends to a signal processor in a receiver, and a receiver. The primary focus of the application is toward the Galileo Public Regulated Service (PRS) Satellite navigation signal.

Abstract: A shaped charge includes an explosive charge having a cavity lined with a laminate liner, the laminate liner comprising a primary liner located adjacent the cavity which forms a non-jet penetrator on detonation, and one or more supplementary liners each of which is less dense than the adjacent liner nearer the cavity. On detonation the liners form a series of penetrators, those formed by the supplementary liners acting to clear a path through an obstruction in front of a target to produce a more efficient attack on the target by that formed by the primary liner.

Abstract: Methods and apparatus for quantum key distribution are described, in particular including methods and networks 300 arranged to improve and/or ensure the security of data transmitted thereby by (i) ensuring a certain level of loss within at least part of the network, (ii) placing a penultimate and an endpoint nodes in situated in a secure second enclave, (iii) analyzing a transmitted bit stream to ensure that it does not provide an unacceptable amount of information about the key that may be generated therefrom, and/or (iv) varying the order in which bits are used to generate a key.

Abstract: Multi-charge munition suitable for defeating a concrete target consists of a detonatable array of hollow primary charges (14) of explosive supported laterally of a line of target penetration on which is disposed a secondary explosive charge (48). Simultaneous detonation of the primary charges in the array causes jet penetrators to be projected together towards the target which produce wide boreholes in concrete suitable for the subsequent emplacement and detonation of the secondary charge. The munition may be an aerially-deliverable bomb or submunition. In one preferred embodiment, the primary charges (14) are positioned in a convergent configuration behind a forwardly-tapered secondary charge (48). Detonation of the primary charges projects penetrators forwardly passed the sides of the secondary charge and thrusts the secondary charge into the borehole produced in the target by the penetrators.

Abstract: A pyrolytic hydrogen generator comprising a pressure vessel containing a plurality of cardboard receptacles for the thermally decomposable hydrogen generating material and an associated ignition system. Also, a modular pellet tray assembly for use in the generator comprises a plurality of trays having pellet holders and associated igniters and held in a stack by support rods that also provide electrical connectivity to the trays.

Abstract: A processor for a radio receiver is adapted to process direct sequence spread spectrum (DS-SS signals), and includes a demodulator, digitiser, correlator, and chip-matched filter (CMF) wherein the digitiser sample rate is selected to take a plurality of samples of each incoming chip at differing points thereon compared to sample points on an adjacent chip and to sample the chip at a non-integer multiple of the chip rate, wherein the CMF is arranged to filter the output of the digitiser. A sample selection unit is arranged to select a single sample from the CMF for input to each tap of the correlator, the selected sample being chosen as that nearest in time to a desired ideal time in relation to a timing reference point on the chip. An improved correlation function results, leading to better tracking performance.

Abstract: A scanned imaging system includes a lens system for directing radiation from a scene to be scanned onto external reflecting surfaces of a rotating polygon and onto a detector, the external reflecting surfaces including primary and secondary flat facets which rotate together on a common axis, the lens system including an image space lens system for focusing an image of the scene to be scanned in the vicinity of a primary facet, and further including an optical system for directing radiation from a primary facet to a focus at a point on or adjacent an associated secondary facet and to reflect the radiation from the secondary facet to the detector, the arrangement being such that a beam of radiation is incident on substantially the whole width of a primary facet and sweeps round with that facet as the polygon rotates.

Abstract: Multi-charge munition suitable for defeating a concrete target consists of a detonatable array of hollow primary charges (14) of explosive supported laterally of a line of target penetration on which is disposed a secondary explosive charge (48). Simultaneous detonation of the primary charges in the array causes jet penetrators to be projected together towards the target which produce wide boreholes in concrete suitable for the subsequent emplacement and detonation of the secondary charge. The munition may be an aerially-deliverable bomb or submunition. In one preferred embodiment, the primary charges (14) are positioned in a convergent configuration behind a forwardly-tapered secondary charge (48). Detonation of the primary charges projects penetrators forwardly passed the sides of the secondary charge and thrusts the secondary charge into the borehole produced in the target by the penetrators.

Abstract: A generally planar, conformable evaporative structure, particularly for incorporation in a garment or an item of personal protective equipment as part of a system to cool the wearer's body, includes an envelope of substantially impermeable, flexible material containing: a layer of flexible wick material disposed adjacent to a major face of the envelope and adapted to hold a working fluid in liquid phase for evaporation by heat conducted through the envelope; a layer of flexible, breathable fabric in parallel with the layer of wick material; and an array of flexible ribs such as open helical coils within the layer of breathable fabric adapted to maintain pathways for the flow of working fluid in vapor phase towards a condensation zone.