Abstract: For protecting a tube to tube plate joint in a tube-in-shell heat exchanger, or for repairing a joint of the same kind which has become defective, a sleeve is employed to bridge the joint and is sealingly secured at one end to the tube plate within the bore thereof and at the other end within the tube. The joint with the tube is a brazed joint. The inside surface of the tube is machined to provide a tapered surface and the exterior surface of the sleeve is machined to provide a matching tapered surface. A land and grooves are formed in the tapered surface, the sleeve is fitted within the tube with the surfaces in engagement, and the brazed joint is made with braze material contained in grooves flowing into a capillary clearance which is of uniform and reproducible dimension from joint to joint.

Abstract: The positive electrode for a lead acid electric storage cell is made by preparing by a chemical route particulate beta lead dioxide, mixing together the beta lead dioxide with a relatively low proportion of a binder, and applying the mixture to a perforated electrically conductive support structure.

Abstract: A positive electrode for a lead acid electric storage cell is made by chemically preparing beta lead dioxide. The beta lead dioxide is then applied to a support structure with a binder, or poured into a permeable, tubular container located about a current collecting rod. The negative electrode can be made by compacting fine lead metal about a carrier, and the fine lead metal might comprise lead wool or particulate lead metal.

Abstract: A plumb bob (11) having an upwardly extending tube (12) is located in a support tube (10) having grooves (20) in which are laid sheathed cables (22). The support tube (10) has windows (21) across groups of which pass the bare conductor elements (23) of the cables (22). The upwardly extending tube (12) forms an energizing electrode and the bare conductor elements (23) form two pairs of orthogonally disposed electrodes (30) capacitatively related to the electrode formed by the upwardly extending tube (12). Horizontal movement of the support (10), and hence any structure in which it is located, creates a capacitative charge between the electrodes which allows the movement to be measured in magnitude and direction. The apparatus has one application to the measurement of horizontal movement in a liquid metal cooled nuclear reactor.

Abstract: A manipulator for remote handling in a hostile environment 14, has a slave arm 10 comprising an upper arm 30, a forearm 52 and a jaw mechanism 60. The upper arm 30 is pivotally suspended from a shoulder support 20 and is telescopically extendible such that straight line motion of the forearm 52 is readily obtained. In addition the forearm 52 is arranged to pivot relative to the upper arm 30 through the same angle as the upper arm 30 but in the opposite sense such that the forearm 52 maintains a constant orientation when the upper arm 30 pivots. All the motions of the slave arm 10 may be controlled through mechanical linkages from a drive unit 18 situated outside the hostile environment 14, and extending through shielding 13 into the environment 14.

Abstract: A plurality of individual filters extend in line across a duct for a gas flow and the duct can be located within secondary containment. The pressure of gas within the duct is less than external pressure and the filters can be supported by a guideway which extends across the duct between opposing walls of the secondary containment with the interior of the guideway communicating with the secondary containment to provide an inward flow purge. The filters in the line are replaced individually by inserting a replacement filter into the line at one end and retrieving the displaced filter at the opposite end of the line.

Abstract: A hand portable probe 11 contains a radioactive source capsule 16 of low energy .gamma. rays which penetrate into an object against which the probe is positioned. Backscattered .gamma. radiation is detected by an annular radiation detector array 14 positioned to be in contact with or very close to the surface under examination. Materials of low atomic number exhibit low photoelectric absorption and can be detected even when concealed behind steel.

Abstract: A transducer, especially suitable for monitoring welds (22), in a sodium-cooled nuclear reactor, has two plates (11, 12) in sliding face contact with parallel slots (13, 14) holding inductively coupled conductors (15, 17). One plate (12) is connected directly to one side of the weld and the other plate (11) is connected via an arm (23) and spacer (24) to the other side of the weld. Multiple slots and conductors can be employed to remove ambiguity from measured signals from the transducer. Multiple transducers can be employed in a scanned X-Y matrix.

Abstract: A method of determining the size of spherical particles, comprising the operations of illuminating with a beam of circularly polarized light particles the size of which is to be determined, detecting light backscattered by the particles, measuring the angular intensity distribution of the backscattered light and deriving therefrom an indication of the size of the particles.Various forms of apparatus for carrying out the method also are described.

Abstract: A process and apparatus are disclosed for the treatment of a substance contained in a solution of a slurry.The solution or slurry is treated in a fluidized bed to give a fusible dried product by use of microwave radiation.The fusible dried product can be heated and fused by use of microwave radiation.

Abstract: A lattice array of metal sheathed mineral insulated cables each cable having a coaxial conductor comprising alternate lengths of dissimilar thermo-electric material to provide thermo-electric junctions. The junctions are in two groups of opposite polarity and those of one group are disposed at the intersections of the cables while those of the other are disposed between intersections. Localized temperature increases create differentials between groups of sensors and can be located by the co-ordinates of the lattice array.

Abstract: A hydraulic shock absorber of the dash pot kind for use with electrically conducting liquid such as sodium, has magnet means for electro magnetically braking a stream of liquid discharged from the cylinder. The shock absorber finds use in a liquid metal cooled nuclear reactor for arresting control rods.

Abstract: A container having a neck 15 is engageable at that neck with a hoist termination 40. The container is supported at the neck 15 by a ball latch 12 in a shielding flask 11 from which it can be lowered through the base of the flask. The termination 40 is provided with a ball latch releasing rod 51 and single-handed raisable and lowerable sleeve 43 which in the raised position allows engagement of the hoist termination 40 and container neck 15 at screw threads 28, 42 but prevents operation of the releasing rod 51 and in the lowered position allows operation of the release rod 51 but prevents disengagement of the hoist termination 40 and container neck 15.

Abstract: A fluidic flow control device includes at least three terminals with two of the terminals being connected to input nozzles opposing each other in axial alignment. An interspace is provided adjacent the point of intersection of the two streams from the nozzles and a radial diffuser is provided encircling the interspace. The third terminal communicates with the radial diffuser. The variable relationship between the flows produced at the nozzles is effective to control the flow at the third terminal. The diffuser is formed by planar faces separated by a constant width gap. The gap opens into an annular plenum to which the third terminal is connected. The entry area to the radial diffuser is sized to be substantially equal to the sum of the areas of the nozzle throats. In one embodiment, a mixer region may be provided between the diffuser and at least one of the nozzles. A fourth terminal acting as a vent may communicate with the mixer region.

Abstract: The present invention relates to the preparation of materials and more particularly to the preparation of tin oxide materials.Thus, the present invention provides a process for the preparation of a tin oxide material by a gel precipitation process which includes contacting together a metal stannate, an organic gelling agent comprising a salt of a polycarboxylic acid and an acidic precipitating agent to form a gel precipitate.The gel precipitate may be treated further to provide the tin oxide material.The tin oxide material may be tin oxide as such, or a mixed oxide material containing tin oxide and an oxide of another element.

Abstract: Reaction-bonded silicon carbide artefacts are produced by siliconizing a green body formed from a coherent mixture of silicon carbide and carbon powders. The surface of the green body is coated with a paste comprising silicon powder suspended in a carbonizable viscous medium which, on heating of the coating, is converted to an open cellular carbon structure and then, on siliconizing the green body, to a silicon carbide skeleton through which molten silicon is drawn.

Abstract: An array of rods is assembled to form a fuel element for a pressurized water reactor, the rods comprising zirconium alloy sheathed nuclear fuel pellets and containing helium.The helium gas pressure is selected for each rod so that it differs substantially from the helium gas pressure in its closest neighbors. In a preferred arrangement the rods are arranged in a square lattice and the helium gas pressure alternates between a relatively high value and a relatively low value so that each rod has as its closest neighbors up to four rods containing helium gas at the other pressure value.

Abstract: The present invention relates to separation and finds application in the removal of liquid from particulate material having associated liquid.The invention provides a process and apparatus for the removal of liquid from a particulate material having associated liquid.In accordance with the invention gas is passed through a bed of particulate material having associated liquid, gas which has thereby taken up liquid is removed from the bed and the particulate material is then removed from the bed via an outlet while resistance to gas flow through the outlet is provided to encourage gas to pass through the bed rather than through the outlet.

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 a gaseous mixture of an organic compound and a gas. The organic compound, the gas and conditions of contacting are selected such that water is extracted from the gel material and passes into the gaseous mixture.The invention in one embodiment may be used to dry gel materials while maintaining an open porous network therein.

Abstract: The invention relates to the use of ternary alloys in brazing ceramics.Brazing is a process of limited usefulness in the fabrication of ceramic components because of the inability of many alloys to wet industrially important ceramics. A possible solution is the metallizing of ceramics but this has technical and economic disadvantages. Alloys are known which wet ceramics but they do not necessarily give good bond strength. The following alloys have now been devised which both wet ceramics and give good bond strength, e.g., greater than 40 MNm.sup.-2 at room temperature, with unmetallized ceramics. The alloys are:Cu: 16 to 28 Ti: 6.5 to 14 SnCu: 15 to 25 Ti: 10 to 25 AuCu: 15 to 50 Ti: 3 to 10 AgCu: 25 to 35 Ti: 3 to 8 Inwherein the compositions are in atom percent.