Abstract: Apparatus and process for creating micro bubbles in a liquid using cavitation are provided. The apparatus includes a rod, cylinder, multi-vanes helical shape or tube with an irregular circumference attached to a drive shaft having a first end and a second end. The first end is coupled to a selectively rotatable power source. The irregular circumference consists of multiple facets having high and low points or areas such that at sufficient angular velocities cavitation zones are created in the liquid following behind each high point. When a gas is supplied to these cavitation zones, the cavitational collapse creates great numbers of micro bubbles which are propelled into the surrounding liquid. Because of their high surface area to volume ratio, these micro bubbles are effective in the transfer of gases such as air and oxygen to a liquid for such purposes as wastewater treatment, aquiculture and gas or stripping of volatile compounds.

Abstract: A collapsible tension-compression variable hull structure that collapses and stores substantially flat, yet deploys in seconds without additional parts or accessories. The tension boat design is a unique prestressed structure that strengthens the hull, reduces the need for ribs and makes the hull easily collapsible for storage and transport. Basically the present invention in it's most simple form or embodiment is a boat comprised of five simple parts: two hard, slightly flexible sides, a waterproof flexible bottom, a line running from bow to stern, and some method of applying tension to shorten the line. In the storage phase, the boat looks like two thin boards with rumpled waterproof plastic attached to the bottom. The sides bow out like an archery bow when tension is applied shortening the line. The exact beam or width of the boat depends on the amount of tension on the line.

Abstract: The invention is directed to a sewage treatment system comprising a tank in which biological treatment by microorganisms occur in mixed liquor and a circulating loop for removing mixed liquor from the tank and returning oxygen enriched aerated mixed liquor to the tank. The mixed liquor is removed and returned to the tank through a pair spaced apart submerged filters. One alternative construction is to use a pressure tank in the circulation loop to increase the percentage of dissolved oxygen in the aerated mixed liquor.