Patents by Inventor Kamalesh K. Sirkar
Kamalesh K. Sirkar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20020180082Abstract: The invention is directed broadly to microporous films prepared from immiscible blends of at least two components, preferably polymers, which are produced via melt processing, a film formed therefrom, for example by extrusion and post-film-forming treatments comprising uniaxial or biaxial cold-stretching and hot-stretching. The films have a three-dimensional reticulated or interconnected network of microcracks or crazing throughout the film, extending from one surface of the film to the other, providing a stable porosity and pore size useful for a variety of filtration and other applications.Type: ApplicationFiled: May 7, 2001Publication date: December 5, 2002Inventors: Chaiya Chandavasu, Marino Xanthos, Kamalesh K. Sirkar, Costas Gogos
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Patent number: 6156096Abstract: A method of separating at least one gaseous component from a feed comprising a mixture of gases using a liquid membrane barrier and a sweep fluid is disclosed that includes selecting a sweep gas or a sweep liquid membrane and providing a treatment zone in a treatment chamber having a plurality of hydrophobic microporous hollow fibers, the treatment chamber having opposed end walls with ports including feed and membrane inlets and a sweep outlet at one end and a sweep inlet and a feed and membrane outlets at the opposed end and a plurality of hydrophobic elongated microporous hollow fibers extending between the feed and sweep inlet ports and feed and sweep outlet ports respectively and arranged for counter-current flow of feed gas and sweep fluids therethrough.Type: GrantFiled: March 26, 1997Date of Patent: December 5, 2000Assignee: Applied Membrane Technology, Inc.Inventor: Kamalesh K. Sirkar
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Patent number: 6110481Abstract: A novel controlled release device employing microporous membranes with or without a nonporous coating and aqueous-organic partitioning of the bioreactive substances to be delivered is provided. Devices and methods for delivering pharmaceuticals, pest-control substances, hormones, nutrients and fragrances to humans, animals or any environment are also provided.Type: GrantFiled: March 4, 1994Date of Patent: August 29, 2000Assignee: Trustees of the Stevens Institute of TechnologyInventors: Kamalesh K. Sirkar, Stephanie Farrell, Rahul Basu
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Patent number: 6022477Abstract: An apparatus and method for recovering bioproducts from a feed solution. In one embodiment, the apparatus includes a module housing, a membrane disposed in the housing for filtering the bioproducts from the feed solution, and an adsorbent bed disposed in the housing for retaining the bioproducts which permeate through the membrane, wherein the apparatus is adapted to allow fractionation and purification of the retained bioproducts from the bed by elution.Type: GrantFiled: November 14, 1997Date of Patent: February 8, 2000Assignee: New Jersey Institute of TechnologyInventors: Robert G. Luo, Kamalesh K. Sirkar
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Patent number: 5993515Abstract: A pervaporation process for selectively removing a component from a multicomponent aqueous solution which is practiced with an assembly comprising a feed chamber for holding and introducting the multicomponent aqueous solution to be treated therein, the feed chamber having a pressure, an exit chamber having a pressure, and located adjacent to the feed chamber and downstream thereof; at least one membrane composite located between the feed chamber and the exit chamber and adapted for fluid registry therewith, the membrane composite comprised of a porous membrane having a first and second surface, and a nonporous membrane permanently disposed on the second surface of the porous membrane, and having a permeability selective to the component, the membrane composite aligned such that the nonporous membrane is connected to the feed chamber; and a vacuum pump connected to the exit chamber for evacuating the component from the chamber.Type: GrantFiled: November 18, 1997Date of Patent: November 30, 1999Assignee: New Jersey Institute of TechnologyInventor: Kamalesh K. Sirkar
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Patent number: 5928409Abstract: In one aspect, a method for selectively removing at least one target component from a multicomponent feed fluid using a removal system, the system including a feed chamber having an inlet and an outlet, a permeate chamber, and a membrane for separating the feed and permeate chambers. The membrane is selective for the at least one target component.Type: GrantFiled: November 12, 1997Date of Patent: July 27, 1999Assignee: New Jersey Institute of TechnologyInventor: Kamalesh K. Sirkar
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Patent number: 5868935Abstract: A novel hollow fiber membrane-based synergistic extraction technique has been developed for removal and recovery of individual heavy metals from aqueous streams. This technique has a number of advantages over conventional solvent extraction, emulsion liquid membrane, and supported liquid membrane methods. It may be easily scaled up to meet the requirements for pollution control of heavy metals in industrial processes and selective separation hydrometallurgy.Type: GrantFiled: March 15, 1995Date of Patent: February 9, 1999Assignee: New Jersey Institute of TechnologyInventors: Kamalesh K. Sirkar, Zhifa Yang, Asim Kumar Guha
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Patent number: 5858385Abstract: A novel controlled release device employing microporous membranes with or without a nonporous coating and aqueous-organic partitioning of the bioreactive substances to be delivered is provided. Devices and methods for delivering pharmaceuticals, pest-control substances, hormones, nutrients and fragrances to humans, animals or any environment are also provided.Type: GrantFiled: July 21, 1997Date of Patent: January 12, 1999Assignee: The Trustees of the Stevens Institute of TechnologyInventors: Kamalesh K. Sirkar, Stephanie Farrell, Rahul Basu
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Patent number: 5753009Abstract: A device and method for selectively removing one or more components from a multicomponent gas/vapor mixture by membrane fractionation. The membrane fractionation gas removal system preferably comprises: a feed chamber which contains the gas/vapor mixture; at least one porous membrane having a first side which contacts the gas/vapor mixture in the feed chamber, and a second side; at least one nonporous membrane having a first side which contacts the second side of the at least one porous membrane, and a second side, the nonporous membrane having a permeability selective to one or more components; an exit chamber connected to the second side of the at least one nonporous membrane such that the component exiting the nonporous gas enters the exit chamber; and an evacuation member connected to the exit chamber for evacuating one or more components from within the exit chamber.Type: GrantFiled: May 14, 1996Date of Patent: May 19, 1998Assignee: New Jersey Institute of TechnologyInventors: Kamalesh K. Sirkar, Jyh-Yao Raphael Li
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Patent number: 5714072Abstract: The instant invention is directed to a method of solvent extraction. The steps of the method include: providing a dual-skinned asymmetric membrane; providing a feed containing a solute; and providing a solvent. The feed and the solvent are contacted across the membrane. The solute of the feed is extracted, and forming thereby a raffinate and an extract.Type: GrantFiled: November 6, 1995Date of Patent: February 3, 1998Assignee: Hoechst Celanese CorporationInventors: Bradley W. Reed, Kamalesh K. Sirkar
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Patent number: 5637224Abstract: A vaporizable solute transfer system for transferring a vaporizable solute from an aqueous feed solution to an extractant liquid comprises a fluid tight housing, a porous membrane which divides the housing into a feed solution chamber and an extractant chamber, and a vacuum atmosphere chamber formed of a nonporous material. The housing has feed solution inlet and outlet ports which communicate with the feed solution chamber, an extraction inlet port which communicates with the extractant chamber, and a vacuum outlet port which communicates with the vacuum atmosphere chamber. The vaporizable solute transfer system also includes a pressure difference control means for maintaining a difference between a liquid pressure of a feed solution chamber and a liquid pressure of an extractant liquid in the extractant chamber substantially within a predetermined pressure range so that an interface between the feed solution and the extractant is substantially immobilized at the membrane.Type: GrantFiled: September 14, 1994Date of Patent: June 10, 1997Assignee: New Jersey Institute Of TechnologyInventors: Kamalesh K. Sirkar, Dali Yang, Sudipto Majumdar, Suphan Kovenklioglu, Amitava Sengupta
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Patent number: 5510257Abstract: Most of the problems of prior art techniques for growing cells in hollow fiber devices can be avoided by growing the cells in short lengths (e.g., two inches (5.0 cm.) or less) of microporous hollow fibers. The fibers are prepared by chopping commercial lengths of hollow fibers into small pieces, preferably two inches (5 cm.) or smaller. Such chopped hollow fibers or bundles of hollow fibers are then added to a suitable medium for growth of cells and the medium is incubated. Very high cell densities have been observed in the chopped fibers.Type: GrantFiled: October 4, 1989Date of Patent: April 23, 1996Inventors: Kamalesh K. Sirkar, Rajesh K. Shukla
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Patent number: 5053132Abstract: An asymmetrically-wettable, porous membrane has a hydrophilic side and a hydrophobic side. The membrane has pores which pass through the membrane to provide communication between the hydrophilic side and the hydrophobic side. The membrane can be used in a process for transferring a solute from a liquid feed solution to a liquid extractant which is substantially immiscible with the feed solution. The process comprises contacting the hydrophilic side of the membrane with one solution and contacting the hydrophobic side of the membrane with the other solution. The interface between the feed solution and the extractant is substantially immobilized at the porous membrane. Solute is transferred from the feed solution to the extractant through the pores of the membrane.Type: GrantFiled: October 10, 1989Date of Patent: October 1, 1991Assignee: The Trustees of the Stevens Institute of TechnologyInventor: Kamalesh K. Sirkar
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Patent number: 4997569Abstract: In a process for transferring solute from a liquid feed solution to a liquid extractant which is substantially immiscible with the feed solution, one side of a porous membrane is contacted with the feed solution and the other side of the membrane with the extractant. One of the feed solution or the extractant preferentially wets the porous membrane. An interface-immobilizing pressure difference is maintained across the porous membrane in a direction and of a magnitude effective to oppose the tendency of the liquid which preferentially wets the membrane to flow through the membrane and disperse in the liquid on the opposite side. The interface between the feed solution and the extractant is thereby immobilized at the porous membrane.Type: GrantFiled: February 6, 1989Date of Patent: March 5, 1991Assignee: The Trustees of the Stevens Institute of TechnologyInventor: Kamalesh K. Sirkar
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Patent number: 4921612Abstract: An asymmetrically-wettable, porous membrane has a hydrophilic side and a hydrophobic side. The membrane has pores which pass through the membrane to provide communication between the hydrophilic side and the hydrophobic side. The membrane can be used in a process for transferring a solute from a liquid feed solution to a liquid extractant which is substantially immiscible with the feed solution. The process comprises contacting the hydrophilic side of the membrane with one solution and contacting the hydrophobic side of the membrane with the other solution. The interface between the feed solution and the extractant is substantially immobilized at the porous membrane. Solute is transferred from the feed solution to the extractant through the pores of the membrane.Type: GrantFiled: June 15, 1988Date of Patent: May 1, 1990Assignee: The Trustees of Stevens Institute of TechnologyInventor: Kamalesh K. Sirkar
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Patent number: 4789468Abstract: An immobilized-interface solute-transfer unit for transferring solute from a feed solution to an extractant liquid comprises a fluid-tight housing and a porous membrane which divides the housing into a feed solution chamber and an extractant chamber. The housing has feed solution inlet and outlet ports which communicate with the feed solution chamber, and extractant inlet an outlet ports which communicate with the extractant chamber. The solute-transfer unit also includes a presure difference controller for maintaining a difference between a liquid pressure of a feed solution in the feed solution chamber and a liquid presure of an extractant in the extractant chamber substantially within a predetermined pressure range so that an interface between the feed solution and the extractant is substantially immobilized at the membrane.Type: GrantFiled: August 28, 1984Date of Patent: December 6, 1988Assignee: The Trustees of the Stevens Institute of TechnologyInventor: Kamalesh K. Sirkar
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Patent number: 4750918Abstract: A permeant gas is selectively transferred from a feed-gas mixture which comprises the permeant gas and at least one other component to an output fluid by the process of the invention. The process involves introducing a selective-permeation liquid into a permeation-transfer chamber. A gas-depletion channel and a gas-enrichment channel pass through the permeation chamber and are separated from the chamber respectively by porous walls. The selective-permeation liquid contacts the porous walls but does not flow into the gas-depletion or gas-enrichment channels. The feed-gas mixture is introduced into the gas-depletion channel so that permeant gas in the mixture can pass through the pores of the walls of the channel into the selective-permeation liquid and from the selective-permeation liquid through the pores of the walls of the gas-enrichment channel into the gas-enrichment channel.Type: GrantFiled: May 28, 1985Date of Patent: June 14, 1988Assignee: The Trustees of the Stevens Institute of TechnologyInventor: Kamalesh K. Sirkar