Abstract: A filtration apparatus is provided which is formed from multilayer presealed elements and monolayer elements that are insert molded together. The device is provided with a feed port, a filtrate port and, optionally, a retentate port. The sealing configuration of the presealed elements and the seal provided by the insert molding step effect a seal configuration that causes a feed liquid to be filtered to form a filtrate such that the filtrate is not mixed with either the feed or a retentate.

Abstract: A single or multiwell plate using membrane, preferably an ultrafiltration membrane to filter selected solutes from a liquid is disclosed. In particular, a preferred construction and method of sealing the membrane to the interior of the well so as to form an integral seal between the top portion of the well and the bottom portion is disclosed. The preferred method is to use a heat seal device which secures the filter to the underdrain portion of the device.

Abstract: The present invention provides methods and devices for producing a subassembly for devices designed to receive particulate matter in a compartment of predetermined shape.

Abstract: A tangential flow filtration apparatus is provided which includes a liquid feed reservoir and a tangential flow filtration module connected together by manifolds. The manifolds eliminate the need for tubular conduits, thereby effecting a reduction in recirculation volume for the apparatus.

Abstract: The present invention provides a filter cartridge or filter unit (11) produced by a thermoplastic overmolding process that allows for using a single mold for overmolding a variety of different sized filter elements (12) or membranes and a method for sealing or hermetically sealing Said filter element (12) in said filter unit (11) or cartridge. The proposed method produces a more robust filter unit (11) or cartridge than those provided by the prior art.

Abstract: A process is provided for selectively removing protein aggregates and virus particles from a protein solution in a two-step filtration process. In a first step, a protein solution is filtered by tangential flow filtration through a cellulosic ultrafiltrate membrane at a transmembrane pressure of between about 1 and about 10 psi to produce a first permeate and a retentate stream. Water or aqueous buffer is added to the retentate stream to form an essentially constant volume retentate stream. The first permeate is filtered through a second ultrafiltration membrane to retain virus particles at a retention level of at least 3 LRV and to allow passage therethrough of a protein aggregate free and virus free protein solution.

Abstract: An electrodeionization-based process for purifying water to remove ionic species is disclosed. Ionic removal is accomplished by supplying an electrical current between an anode and a cathode of an electrodeionization module in the range of about 1.5 to 15 times a “theoretical minimum current”. The current is supplied by a power source capable of automatically increasing or decreasing voltage in response to a change in the electrical impedance of the electrodeionization module to maintain constant current. Conduct of the process on pretreated water yields deionized water of good quality, while maintaining conditions that promote the longevity of the electrodeionization module.

Abstract: A porous membrane product is provided which is formed from a porous membrane substrate having its surface completely modified with a perfluorocarbon copolymer composition. The porous membrane product has substantially the same permeability as the porous membrane substrate.

Abstract: A single or multiwell plate using membrane, preferably an ultrafiltration membrane to filter selected solutes from a liquid is disclosed. In particular, a preferred construction and method of sealing the membrane to the interior of the well so as to form an integral seal between the top portion of the well and the boftom portion is disclosed. The preferred method is to use a heat seal device which secures the filter to the underdrain portion of the device.

Abstract: A seal, a vent for a filter housing and a system for using them. The seal is designed a first outer seal having a closed outer periphery that divides and isolates a first inner area from the outside environment and a second inner seal formed along a portion of the inner surface of the first outer seal and forming a second inner area within the first inner area and which is isolated from both the first inner area and the outside environment. The seal is incorporated into a vent for a filter housing having opening is contained within a vent area and the opening is offset from the center of the vent area. The opening establishes a fluid pathway from the interior to the exterior of the filter device. The inner seal surrounds the vent opening. The outer seal also surrounds the vent opening at one of its ends and surrounds the entire periphery of the vent area so as to isolate the vent area from the area outside of the vent area.

Abstract: A porous membrane product is provided which is formed from a porous membrane substrate having its surface completely modified with a perfluorocarbon copolymer composition. The porous membrane product has substantially the same permeability as the porous membrane substrate.

Abstract: A method and apparatus for sampling microorganisms from the air is disclosed. The speed at which the sample is placed on to a growth medium is controlled, such as by controlling the speed of the turbine of the device, so as to compensate for any drying of the medium that may have occurred by the amount of air hitting the surface over time. This enhances the ability of the medium to retain microorganisms present in the air even as the medium dries from the flow of air over its surface.

Abstract: A porous membrane is provided which is formed from a porous polyperfluorocarbon membrane substrate having its surface modified with a perfluorocarbon polymer composition. The modified surface is directly wet with an aqueous liquid.

Abstract: A gas driven pump controls the process fluid pressure within a filtering and dispensing system. A pressure controller in the pump controls gas pressure within an enclosed chamber in the pump. The gas chamber is adjacent a floating piston that rests atop a layer of incompressible fluid in a fluid chamber. The incompressible fluid connects to a diaphragm head. As the gas pressure is increased, the floating piston will transmit that pressure through the incompressible fluid that then forces a relative displacement in the process fluid flow. A feedback system used in conjunction with the gas driven pump controls the gas pressure in order to regulate the process fluid flow.In addition, a positive displacement compensator can be used in conjunction with the gas driven pump in order to further regulate the process flow.

Abstract: This apparatus has a sieve (4) with a wall (22) perforated with a multitude of holes, means (4, 5) for holding a removable receptacle (20) containing a layer of growth media (21) and means (7, 8) for sucking in air at the periphery of the receptacle (20) in order to cause to enter the apparatus (1), through holes in the wall (22), air which strikes the layer of growth media (21), the latter and the wall (22) being shaped so that their separation increases from their periphery towards their center.

Abstract: A process and composition for removing metal carbonyls and moisture from a gas wherein the gas is contacted with a metal oxide, an organometallic oxide or mixtures thereof having a reduction potential greater than about 0.175 volts and a composition capable of removing moisture from the gas.

Abstract: A process and composition for removing metal carbonyls and moisture from a gas wherein the gas is contacted with a metal oxide, an organometallic oxide or mixtures thereof having a reduction potential greater than about 0.175 volts and a composition capable of removing moisture from the gas.

Abstract: The cartridge has a body (2) with a grid (7) and an annular wall (8) oriented transversely to this grid and surrounding it, and having a layer (3) of growth media and a flexible fluid-tight film (4) tensioned over an end surface of the annular wall (8) and delimiting an end surface of the layer of growth media (3).According to the method, the surface of the layer of growth media (3) delimited at the time of manufacture by the tensioned film (4) is struck with air jets in order to impact on this surface the microorganisms present in the air.The apparatus has a positioning support common to a sieve for forming the air jets and to the body (2) of the cartridge (1).

Abstract: A process and composition for removing moisture from a NF.sub.3 or F.sub.2 gas wherein the gas is contacted with alumina particles coated with aluminum trifluoride. The aluminum trifluoride is formed by reacting alumina particles with an aqueous solution of hydrogen fluoride.