Abstract: The system includes a boiler, and multiple radiators connected to the boiler via a network of pipes. It includes a central processor for monitoring and control, air vent controllers that control the flow of steam through the radiators and a boiler control which turns the boiler on and off. The radiators are divided into groups. The central controller communicates with the air vent controllers to determine the conditions in the various groups. Based at least in part on the conditions, central controller may determine that the group requires heat. If heat is required and other parameters agree, central processor determines the state of the boiler. If off, the boiler is instructed to turn on and the air vent controllers in the group are instructed to open. Each air vent controller in that heat zone will then open allowing air to flow through the radiator and heat to be provided.

Abstract: The biocompatibility of various polymers are improved by blending with them a polymer including a zwitterionic group. The zwitterionic group is usually an ammonium phosphate ester zwitterionic group and the polymer containing it may be produced by the free radical polymerisation of ethylenically unsaturated monomers including a monomer bearing the zwitterionic group. Blending of the two polymers may be achieved by dry blending particulate polymers or by mixing the polymers in liquid dispersion or solution followed by removal of the liquid medium. The fibrinogen absorption and/or platelet activation of polymers may be reduced to a value of less than 80% or even less than 60% of the base polymer by introducing amounts of more than 10% or more than 30% of the zwitterionic group containing polymer. Preferred blends are of copolymers of 2-(methacryloyloxyethyl)-2′-(trimethylammonium)ethyl phosphate inner salt with higher alkyl(meth)acrylate, blended with olefin polymers and/or with rubber latices.

Abstract: Disclosed is a polymer blend composition and shaped article, and a process of blending and making shaped articles of polymer blends in which the biocompatibility of various polymers is improved by blending with them a polymer including a zwitterionic group. The zwitterionic group is usually an ammonium phosphate ester, preferably a choline, zwitterionic group and the polymer containing it may be produced by the free radical polymerization of ethylenically unsaturated monomers including a monomer bearing the zwitterionic group. Blending of the two polymers may be achieved by dry blending particulate polymers or by mixing the polymers in liquid dispersion or solution followed by removal of the liquid medium. The fibrinogen absorption and/or platelet activation of polymers may be reduced to a value of less than 80% or even less than 60% of the base polymer by introducing amounts of more than 10% or more than 30% of the zwitterionic group containing polymer.