Abstract: The present invention relates to composite articles including a surface layer of tin, lead, silver or an alloy thereof that contains co-deposited non-ionic polymeric particles to provide a reduced-friction deposit that has an initially low coefficient of friction and low insertion force and fretting corrosion in separable electronic connectors, and to methods for preparing the plated articles. The polymeric particles have a size between about 0.1 to 0.45 .mu.m in diameter to reduce the coefficient of friction of the resultant deposit to about 0.45 or below. Also, the deposit has excellent electrical properties and can be successfully soldered. The invention also relates to a solution for plating the surface layer of the composite articles, which surface layer reduces insertion force and fretting corrosion of separable electronic connectors.

Abstract: The present invention relates to a solution and method for plating tin, lead, or tin-lead alloy deposits which contain a co-deposit of fluorocarbon particles to provide a lower-friction solder-type deposit which reduces insertion force and fretting corrosion in separable electronic connectors. The fluorocarbon particles have a size between about 0.1 to 1 .mu.m in diameter, and reduce the coefficient of friction of the resultant deposit to 0.8 or less. Also, the deposit has excellent mechanical properties and can be successfully soldered.

Abstract: An improved system for aerating and mixing waste water which is circulated through a plurality of passages in submerged mixing chambers from an inlet to outlet of each wherein gas is mixed with the water, preferably by forming two parallel streams. To flush debris from the mixing chambers and conduits: (1) each inlet is connected to a location higher than the inlet, and at a lower pressure; (2) circulation of water is stopped; and (3) gas is continued to be forced into the passages to create backward flow of waste water through each chamber from outlet to inlet and thence to the higher location, carrying lodged debris out of the chambers and conduits. Intermittent gas flow creates pulsations which help dislodge debris.

Abstract: An apparatus for treatment of waste water in a body such as a lagoon in which a submerged aeration device is suspended from a floating platform. Air is supplied to the aeration device by a conduit passing through the buoyant base of the platform to a central opening so that the conduit is an integral, structural part of the platform.

Abstract: An improved system for mixing gas with waste water in which the water is pumped through a plurality of mixing chambers into which the gas is injected at a step region to form parallel streams of gas and water. An extending chamber contains the parallel streams as the interface between them becomes unstable, breaks down creating vortices and produces tiny bubbles which mix with the water. The extending chamber is divided into two sections with at least the section remote from the step surface tapered inwardly at a rate of 11.degree.-22.degree. to permit operation at higher air flow rates without blowing the bubble forming vortices out of the chamber.

Abstract: An improved system for mixing gas with waste water in which the water is pumped through a plurality of nozzles or vortex mixing chambers into which the gas is injected at a step region to form parallel streams of gas and water. The multiple stage nozzle includes an extending chamber which contains the parallel streams as the interface between them becomes unstable, breaks down creating vortices and produces tiny bubbles which mix with the water. The extending chamber is divided into three sections or stages with at least one section tapered inwardly at a rate of 11.degree.-22.degree. to permit operation at higher air flow rates without loss of efficiency and the outermost section from which the mixed stream is directly discharged into the body of waste water being non-diverging, preferably cylindrical.

Abstract: An improved method and system for mixing gas with waste water in which the water is pumped through a plurality of mixing chambers into which the gas is injected at a step surface to form parallel streams of gas and water. An extending chamber contains the parallel streams as the interface between them becomes unstable, breaks down creating vortices and produces tiny bubbles which mix with the water. The extending chamber is tapered inwardly to permit operation at higher air flow rates without blowing the bubble forming vortices out of the chamber. Helical vanes are preferably provided in the passages which inject the air into the extending chamber to create better wave generating conditions to extend the range to greater air flow rates.

Abstract: An improved method for aerating and mixing waste water which is circulated through a plurality of passages in submerged mixing chambers from an inlet to outlet of each wherein gas is mixed with the water, preferably by forming two parallel streams. To flush debris from the mixing chambers and conduits: (1) each inlet is connected to a location higher than the inlet, and at a lower pressure; (2) circulation of water is stopped; and (3) gas is continued to be forced into the passages to create backward flow of waste water through each chamber from outlet to inlet and thence to the higher location, carrying lodged debris out of the chambers and conduits. Intermittent gas flow creates pulsations which help dislodge debris.