Abstract: An irrigation system, such as of the self-propelled type with a series of self-propelled support towers for supporting and moving an irrigation conduit over a field to be irrigated, the conduit comprised of a series of conduit sections supported by the towers. The system is for use on sloping or uneven terrain causing tension or compression loads in the system, and includes a control for sensing such a load and for controlling the movement of selective support towers to relieve the load. Included is a coupling for joining adjacent conduit sections which senses the relative displacement of said sections caused by said load. Also included is a steerable support tower which is steered in response to the coupler sensing said displacement to relieve said load.

Abstract: Antifouling compositions or paints with a high degree of stability and toxic to marine life comprising the combination of (a) cuprous oxide; (b) one or more triorganotin polymer or copolymer carboxylates and (c) at least one relatively inert dehydrating agent of low water solubility which is capable of taking up water either physically or chemically; and optionally also comprising other toxic or non-toxic resin or pigment components, non-aqueous diluents, thinners, extenders or solvents, together with other conventional additives.The component (c) is preferably a relatively inert metal salt of low water solubility, e.g. calcium sulphate in anhydrous or hemi-hydrate form and the polymer or copolymer is generally a substituted or unsubstituted vinyl or acrylic triorganotin polymer or copolymer carboxylate, copolymers being preferred to give the desired choice of physical or mechanical properties.

Abstract: A TDM PCM communication system includes a plurality of user terminals, a switching network and a CPU for controlling the establishment of transmission paths between the user terminals and the switching network for the transfer of information between predetermined ones of the user terminals. An incoming path carries information bits from the user terminals to the switching network and an outgoing path carries information bits from the switching network to the user terminals. The switching network includes means for transferring single information bits each residing in a time slot period from the incoming path to the outgoing path. The transferring means includes an exchange means for effecting a bilateral exchange of information bits in fixed pairs of time slot periods, whereby paths for information bit transmission are periodically provided between ones of the user terminals, as determined by the CPU.

Abstract: A pair of interchangeable memories is provided, one of which receives a PCM frame while simultaneously transmitting one, while the other of which, containing the previous frame, outputs the channel bits for parallel processing. Each simultaneous conference is assigned a temporary storage location in which the associated channels are accumulated to yield the total conference signal. Subsequently, each channel is subtracted from its conference total to produce the final conference signal. The final conference signals replace the unprocessed frame in the memory where, at the end of the current frame, it is interchanged with the other memory. And so on.