Abstract: A multiport distribution network is provided that supports N inputs and N outputs, where N>1, the multipart distribution network providing an independent distribution path extending from each input to each output, each path being formed from a sequence of at least two fundamental units. Each fundamental unit comprises a circuit formed of multiple resonator cavities and having n input ports for receiving respective input signals, and n output ports for outputting respective output signals, where n>1, and wherein the circuit is configured to: (i) at each input port, split an input signal received at that input port into n equal signal components and provide each of the n signal components to a respective output port of the circuit; and (ii) at each output port, combine the signal components received from the n input ports to form an output signal for that output port. The multipart distribution network is configured to apply the same filter transfer function along each independent distribution path.

Abstract: A multiport distribution network is provided that supports N inputs and N outputs, where N>1, the multipart distribution network providing an independent distribution path extending from each input to each output, each path being formed from a sequence of at least two fundamental units. Each fundamental unit comprises a circuit formed of multiple resonator cavities and having n input ports for receiving respective input signals, and n output ports for outputting respective output signals, where n>1, and wherein the circuit is configured to: (i) at each input port, split an input signal received at that input port into n equal signal components and provide each of the n signal components to a respective output port of the circuit; and (ii) at each output port, combine the signal components received from the n input ports to form an output signal for that output port. The multipart distribution network is configured to apply the same filter transfer function along each independent distribution path.

Abstract: The invention provides a profiled polymer filament having an open hollow cross-sectional shape normal to the longitudinal axis of the filament, wherein the cross-section is dimensioned to prevent the filament from interlocking with a second filament of the same cross-section. The invention also provides methods of manufacture of such filaments by melt spinning a polyamide, and spinnerets suitable for use in melt spinning such filaments.

Abstract: The invention provides a profiled polymer filament having an open hollow cross-sectional shape normal to the longitudinal axis of the filament, wherein the cross-section is dimensioned to prevent the filament from interlocking with a second filament of the same cross-section. The invention also provides methods of manufacture of such filaments by melt spinning a polyamide, and spinnerets suitable for use in melt spinning such filaments.

Abstract: Methods of making gel materials are disclosed including mixing a water soluble crosslinkable matrix polymer, a particulate polymer material which has been crosslinked to a gel content of at least 55% and an aqueous solvent, and crosslinking the matrix polymer to form a gel matrix of the matrix polymer in which the particles of particulate polymer material are dispersed, each of the crosslinked matrix polymer and the crosslinked particulate polymer material being capable of absorbing water. Gel materials are also disclosed including particles of a particulate polymer material capable of absorbing water and which is crosslinked so that it has a gel content of at least about 55% dispersed in a matrix of a polymer which has been crosslinked to reduce its solubility in water so that it swells rather than dissolves in water, the size of at least 60% by weight of the particles of particulate polymer material being less than about 100 &mgr;m.

Abstract: There is disclosed a composition for use as a flux material in a tinplating process, which comprises an aqueous solution of one or more hydroxy phenyl compounds of general formula (I), wherein M=a cationic species, preferably H, substituted or unsubstituted ammonium, alkali metal, alkaline earth metal or tin; R=H, C1-C6 linear or branched alkyl, alkoxyl or alkenyl, or aryl (which may be substituted); m=2 or 3; n=0, 1 or 2, the composition containing from about 0.1 g/1 to saturation of said compound of general formula (I). There is also disclosed a process for treating matte tinplate and a process for tinplating using such composition.

Abstract: A swimming aid which includes a main body having a support section by which the swimming aid is carried by the user and a fin section which extends away from the support section and includes a distal free edge portion and spaced apart side edge portions extending between the distal free edge portion and the support section, and at least one elongated substantially resilient element extending from the support section towards the distal free edge portion of the fin.

Abstract: This invention relates to a process for producing low molecular weight phenol-aldehyde resin which has predominantly 4 phenolic units in a chain and in which the phenolic ring has a substituent R which is an alkyl group and optionally contains methylol groups on either end of the chain, by reacting formaldehyde with p-alkyl phenol in the presence of ammonia as base in a liquid reaction medium. The resins can be used in producing demulsifiers.

Abstract: This invention relates to a process for the production of a polyoxyalkylene derivative of a phenolic resin, by reacting under base-catalyzed conditions the phenolic resin with the appropriate alkylene oxide(s) so that the polyoxyalkylation is carried out by: A) using a phenolic resin which has a water content of less than 0.5% w/w, B) reacting the phenolic resin initially with about one mole of the alkylene oxide(s) per mole of the resin in the absence of a base catalyst in an inert atmosphere at a temperature below 140.degree. C. until the partial pressure of the alkylene oxide(s) reactant is substantially neutralized, and C) reacting the product from step (B) above with the remainder of the alkylene oxide(s). These derivatives are good emulsifiers and demulsifers.