Abstract: Apparatus for plant cell tissue culture including a plant growth enclosure having a bottom surface formed of a porous material, a buoyant element, separate from the plant growth enclosure and arranged to be placed thereunder in a body of liquid for supporting the plant growth enclosure, and spacer apparatus associated with at least one of the plant growth enclosure and the buoyant element for maintaining a predetermined separation between the buoyant element and the porous material.

Abstract: The invention is a membrane comprising polymerized monomer and oligomer components. A primary membrane oligomer component is selected from acrylic polyester urethanes, and a secondary membrane monomer component is selected from 1,1,3,3-tetramethylbutylacrylamide and perfluoromonomers and perfluoroacrylic monomers. The membrane is further characterized as being microporous, permeable and having a thickness of less than 0.1 inches.

Abstract: The starting materials for the practice of the present invention are (1) one or more organic monomers or oligomers which upon irradiation very rapidly undergo a polymerization reaction to form a solid polymer; and (2) a liquid vehicle in which the one or more organic monomers or oligomers are soluble but in which the polymer formed is insoluble. For the manufacture of microporous membrane in accordance with the invention the monomers or oligomers are dissolved in the liquid vehicle, the resulting solution is formed into a thin layer, and the thin layer of the solution is then irradiated as with ultraviolet or electron beam radiation whereupon the rapid polymerization reaction immediately ensues and the polymer formed immediately segregates from the vehicle thereby resulting in microporous membrane from which the vehicle can be removed as by evaporation or washing.

Abstract: A fluid purification system for performing filtration of particles from a feed liquid by a tangential flow of the feed liquid over a membrane surface. In one embodiment, the purification system includes a filter cartridge contained within a filter housing having ports permitting ingress and egress of feed liquid and filtrate. The cartridge includes a filter element having a layered construction with a thin flow channel between the layers. One layer of the filter element is formed of a sheet of impervious material defining one wall of the thin flow channel. Another layer of the filter element is spaced from the one layer and formed of a sheet of permeable membrane material and defines another wall of the thin flow channel. The spacing between the walls of the thin flow channel is maintained by a sheet of reticular material that provides turbulence in the thin flow channel to promote cross flow filtration. The filter element is formed into a pleated, cylindrical shape with a flow axis parallel to the pleats.

Abstract: According to the present invention there is provided a novel type of membrane unit for use in electrodialysis comprising a heat-sealable frame framing and forming an integral entity with an electrodialysis membrane. The frame may be a regular frame, or a two-frame structure framing a single membrane. The invention further relates to electrodialysis devices such as stacks, bags, cells, spiral units and the like based on such membrane units, which are hermetically bonded by heat-sealing to similar units or to polymeric or other members.