Abstract: A rotary drum comprises a hollow cylindrical outer member, a coaxial hub, and a plurality of spokes pivotally connected to the outer member and to the hub, all the spokes being aligned at the same oblique angle to the radius at the respective connections to the hub. Thermal expansion of the outer member relative to the spokes is accommodated by rotation of the outer member relative to the hub and a consequent change in the oblique angle, so minimizing thermally induced stresses in the spokes. The drum may be used in the production of a metal by deposition from the vapor phase onto the outer surface of the drum.

Abstract: To monitor the deterioration of a weld (10) between a tube (11) and tube plate (12) which has been repaired by a repair sleeve (14) inside the tube and brazed at one end to the tube, ultrasound from a crystal (21) at the end of a rod (24) is launched into the tube through the braze (15) and allowed to travel along the tube to the weld and be reflected back along the tube. The technique may also be used for the type of heat exchanger in which, during construction, the tubes are welded to the tube plate via external sleeves in which case the ultrasound is used in a similar manner to inspect the sleeve/tube plate weld.

Abstract: Equipment for investigating crack propagation in thick steel plates of a material with applicability for pressure vessels comprises a test specimen in the form of a hollow cylinder of the material under investigation, a vertical spindle from which the hollow cylinder is suspended and which can be rotated at a speed of the order of thousands of revolutions per minute, damping means for damping against flexural resonance vibrations of the cylinder and spindle, a container for the cylinder and means for supplying hot air to the container via a port, means for applying through a port in the container, a jet of cold fluid on to a surface of the cylinder to apply thermal shock thereto the spindle being hollow to accommodate leads from instrumentation on the cylinder to a slip ring unit from which leads to control and recording equipment extend, the instrumentation serving to monitor crack propagation under the conditions of high speed revolution which induce a hoop stress in the material approaching its yield stren

Abstract: An induced current heating probe is of thimble form and has an outer conducting sheath (30) and a water flooded flux-generating unit formed from a stack of ferrite rings (10) coaxially disposed in the sheath. The energizing coil (14) is made of solid wire which connects at one end (16) with a coaxial water current tube (15) and at the other end (17) with the sheath. The stack of ferrite rings (10) may include non-magnetic insulating rings (11) which help to shape the flux.

Abstract: A composite cathode for a solid state electrochemical cell is made by forming a sheet or film from a solution of an insertion electrode material (e.g. V.sub.6 O.sub.13) and a polymeric material (e.g. (PEO).sub.x LiF.sub.3 CSO.sub.3), e.g. by solution casting. The sheet or film is subjected to densification by application of pressure thereto (e.g. by rolling) and assembled into a cell in conjunction with an anode having lithium as its active material and an electrolyte comprising a polymeric material capable of forming a complex with a Li salt, a Li salt being complexed with a polymeric material to form an ionically conducting phase in one or both of the composite cathode and the electrolyte. The overall volumetric energy density and capacity retention of the cell are thereby enhanced.

Abstract: A conductive strip for attachment to an aircraft radome to provide protection against the effects of a lightning strike to the radome, wherein the conductive strip has a series of holes formed in it.

Abstract: To increase the creep strength of a titanium-containing alloy which also contains chromium, the alloy powder is heated in the presence of ammonia at a temperature of the order of 700.degree. C. so as to form a layer of chromium nitride(s) on the particles and is then heated further in an inert atmosphere at a temperature between 1000.degree. C. and 1150.degree. C. to dissociate the chromium nitride(s) thereby effecting nitriding of the titanium to titanium nitride which affords dispersion-strengthening of the alloy.

Abstract: Irradiated nuclear fuel pins (30) comprising metal-sheathed refractory pellets are rendered into short lengths by notching at a pair of notching wheels (14) and providing a deflector block (18) against which the notching wheels drive the notched pins to bend and brake them at the notches.

Abstract: The present invention relates to the treatment of gel materials to remove water therefrom. The invention provides a process for removing water from a gel material by contacting the gel material with an organic liquid and contacting the organic liquid with a gas such that water is taken up by the gas. The invention, in one embodiment, may be used to dry gel materials while maintaining an open porous network therein.

Abstract: An ultrasonic scanning probe 10 for inspecting structures for internal defects and providing a plan position display comprises a transducer 70 mounted within a block 12 of ultrasonically absorbent material, such as polyethylene, adjacent to a window 30 which may be placed in contact with a surface of the structure. The block 12 is turnable about a rotation axis normal to the window 30, while the transducer 70 is oriented at an angle to the axis so as to scan a sector of the surface as the block 12 is turned, and an attenuating coupling medium 160 occupies the space between the transducer 70 and the window 30. The scanning probe 10 may be used in wet or dry situations.

Abstract: Plant cells containing intra-cellular chemical compounds are induced to excrete the compounds by maintaining the cells in a sufficiently high cell density. A sufficiently high cell density is preferably maintained by immobilizing the cells in a modified polyacrylamide gel containing polyacrylamide and a minor amount of xanthan gum or sodium alginate. Vinca plant cells can be immobilized to produce the chemical compounds, ajmalicine and serpentine. Alternative to immobilizing the cells, a sufficiently high cell density can be provided by maintaining the cells in a permeable enclosure such as a woven nylon bag.

Abstract: A source for the provision of ions or charged droplets of a liquid metal, consisting of a needle having an emitting tip, a reservoir for a liquid metal, ions or charged droplets of which are to be emitted by the source, and a sheath surrounding the needle and from which the needle projects. The sheath serves to convey liquid metal to the emitting tip of the needle at a controlled rate. There is provided a device for withdrawing the emitting tip of the needle into the sheath so as to enable the emitting tip of the needle to be immersed in the liquid metal.

Abstract: The present invention relates to the preparation of materials and finds application in the preparation of dispersions and gels.The invention provides, in one aspect, a process for the preparation of a dispersion which comprises treating a chemical compound with a quaternary ammonium hydroxide so as to peptize the chemical compound to form a dispersion.The dispersion may be, for example, a suspension or a sol (i.e. a colloidal solution). The chemical compound may be, for example, a hydrous metal oxide (e.g. hydrous stannic oxide).Mixed dispersions may be formed in accordance with the present invention.

Abstract: An optical alignment system in which an aligning beam of radiation is caused to scan around the periphery of an alignment aperture. Light reflected from the edge of the alignment aperture is collected and a related electrical signal is produced. If the alignment aperture is accurately centered with respect to the motion of the aligning beam, then the electrical signal will be constant. Any lack of centralization will cause variations in the electrical signal. The amplitude and phase of these variations relative to the motion of the aligning beam are indicative of the direction and amount of the decentralization of the alignment aperture with respect to the aligning beam. Hence these parameters are measured and used to operate a servo mechanism which is arranged to move the alignment aperture to centralize it with respect to the aligning beam.The alignment aperture may form part of an optical system, or be attached to a piece of equipment the alignment of which it is desired to maintain.

Abstract: An apparatus and a method are provided for separating liquid from small spheres, for example spheres formed by gel precipitation. The apparatus comprises sloping screening decks (12, 14), arranged in stepped relationship so that spheres tumble down onto the lower screening deck (14) after passing along the upper screening deck (12), each screening deck comprising a large number of upright plates (30, 60) spaced apart from each other and extending in the direction of slope, so that the liquid drains down between the plates. Alternate plates might be replaced by rods when separating extremely small spheres from a liquid.The apparatus has no moving parts, and even after inflow of the liquid stops, the spheres still continue to pass through the apparatus.

Abstract: A threshold temperature is detected by providing a sensor (12) comprising a magnet (13) inside a ferromagnetic shield (14) which has a lower Curie point than that of the magnet. Below threshold the sensor is magnetically characterless. Above threshold the sensor displays a magnetic character which is detected at a solid-state magnetometer (16). In one application the sensor is located in a breeder fuel sub-assembly (20) at the breeder/fuel region (22) of a fast-fission nuclear reactor and the magnetometer is located in a fuel sub-assembly (21). In another application the sensor is located inside a sealed containment vessel and the magnetometer is located outside the vessel.

Abstract: A bracing grid (27) made from joggled strip (20) and which is one of a number of similar grids supporting fuel pins (26) in a fuel sub-assembly for a nuclear reactor is characterized in having the peripheries of the grids completed by unit edge cells (21). Where the periphery of the grids accommodate sub-assembly corner posts (30) the continuity of the unit edge cells is maintained around the corner posts.

Abstract: Failed fuel detection apparatus for nuclear reactors cooled by liquid metal has a pump (11) for impelling coolant metal along sampling pipes (10) to outlet points (10a) in the pipes. A rotary collector (15) is provided to scan the outlet points with a gap between the outlet points and the collector across which coolant in the sampling pipes can be impelled. The pump (11) is preferably of the helical annular linear induction type with the pipes passing through the annulus of the pump while being wetted internally and externally by liquid metal.

Abstract: Prior to effecting a repair of a leaking heat exchanger tube by an internal repair tube brazed to the leaking tube, strain in the leaking tube is measured while heating it to brazing temperature. A braze is only effected if the strain is below a predetermined level. Apparatus for carrying out the strain measurement typically of probe form having a strain gauge head (21) at the nose of the probe and a heater element (23). Preferably, the length of the probe is such that the head (21) reaches to just above a grid support plate (12). Where strain is found to be above said predetermined level and the leaking tube is of U-shape the strain may be relieved by heating both legs of the tube. Alternatively, strain may be relieved by thinning and bulging the leaking tube (FIGS. 5A-C) at a region close enough to the braze for the thinned zone to experience heat from the braze to allow it to yield under the strain.

Abstract: A nuclear fuel cartridge comprises a sheath, and nuclear material inside the sheath. A continuous liquid permeable passageway extends from one end of the nuclear material to the other, and an annular end member is disposed at each end of the nuclear material. Inner spacing members also of annular form may be disposed in intermediate positions along the sheath between portions of the nuclear material.