A boat hull or part thereof produced by applying layers of curable resin to a mould or former and curing the resin in the mould or on the former. A layer of a non-biocidal antifouling material is applied to the mould, or to the outermost layer of resin if using a former, so that the non-biocidal antifouling material forms the outermost layer of the boat hull. A non-biocidal antifouling material used as the outermost underwater surface of a boat hull has fine grooves extending in the longitudinal...

An annular combustion chamber comprising a plurality of ducts adapted to ect axially in an upstream direction a gasiform mixture containing vaporized fuel, each duct being associated with a pair of radial nozzles adapted to inject into said chamber two air jets directed toward one another, the geometrically defined area in which the jets are to meet being located at the outlet end of said duct.

Frozen solid particles are obtained from liquids such as dairy produce, liquid egg, microbiological cultures and pharmaceuticals, by direct contact with liquid nitrogen in an enclosed insulated vessel which includes nozzles for injection of liquids into conduits with contact channels additionally cooled by countercurrent flow of liquid nitrogen in cooling channels. A separation auger removes partially frozen product from the liquid nitrogen and completes its freezing by contact with cold nitroge...

Wind energy conversion apparatus comprises vertical endless travelling belt means and a plurality of inter-spaced hydrodynamic foil members mounted thereon. Passage of fluid, i.e. wind, over the foil members creates lift forces thereon serving to drive the endless belt means about belt circulating parts. The foil members may have a fixed angle of incidence with respect to the belt runs i.e. between the circulating parts at the top and bottom of the endless belt means; or they may be of variable ...

A razor formed as a unitary moulding comprises a main body 1 including a cap member 3 and two side walls 4 and a guard member 6 connected to the body 1 by spring fingers 7 and living hinges which permit the guard member to be located in guide means 9 which guide the guard member for limited displacement during shaving.

A flexible windscreen wiper arm (1) of unitary construction, having means (2, 3) at one end of the arm for attachment to a wiper blade, and means (6) at the other to engage a rotary driving spindle (8). Between the two ends of the arm is a region (12) capable of toggle action between two opposite and stable positions. When the socket (6) is in place over the spindle (8) and the toggle region is in one stable position, the socket grips the spindle and the blade will be angled so as to press the b...

A calender bowl comprises a central elongate shaft having a flange at each end thereof. This arrangement defines a region which is filled with a filler material. The region to be filled with the filler material is the annular area around the shaft and it is filled by transversely threading numerous disc-shaped sheets of fibre and possibly conducting discs, thereon. Copper rods are disposed within the filler, along all or part of the length of the calender bowl, and lie in thermal contact with th...

A roller door assembly has means for tensioning same wherein a load is applied to a bottom edge of the roller and means for counterbalancing the weight of the door wherein a load is applied to the roller, the loads exerted by both said means being dependent on the amount of door off the roller.

A conveyor is made up from a plurality of module bodies 11. The body 11 includes a restraining member 18 having a portion 20 which extends downwardly from the middle of the body 11 under portion 19 which extends outwardly to either side from the lower end of the portion 20. The restraining member 18 co-operates with a sleeve 23 of a fixed guide member 22 to resist movement to the left (when seen in the Figure) or upwards movement of the conveyor portion when the portion undergoes a left hand tur...

The invention provides compounds of the formula XX: M-Ar-CONH-R, where Ar represents an aromatic ring system, R-NH is the residue of an .alpha.-amino acid R-NH.sub.2 or oligopeptide R-NH.sub.2 and contains at least one carboxylic acid group in the form of a tertiary butyl ester and M represents a nitrogen mustard group of formula (a), where Y and L, which may be the same or different in a molecule, are leaving groups. The compounds are useful intermediates for the production of nitrogen mustard ...