Patents by Inventor Saad A. Khan

Saad A. Khan 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).

  • Patent number: 5965299
    Abstract: A composite electrolyte comprises (a) surface modified fumed silica filler, wherein the surface modified fumed silica comprises polymerizable groups on the surface thereof, the polymerizable groups being bonded to each other such that the surface modified fumed silica filler is crosslinked in a three-dimensional structure; (b) a dissociable lithium salt; and (c) a bulk medium which contains the surface modified fumed silica filler and the dissociable lithium salt. An electrochemical cell comprises an anode, a cathode, and a composite electrolyte dispersed between the anode and cathode.
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: October 12, 1999
    Assignees: North Carolina State University, Michigan State University
    Inventors: Saad A. Khan, Peter S. Fedkiw, Gregory L. Baker, Jiang Fan, Srinivasa R. Raghavan, Jun Hou
  • Patent number: 5900112
    Abstract: A method of recycling sodium-based salts used for digesting wood in a digester during the manufacture of pulp and paper. The method comprises collecting a black liquor from the digester, concentrating the black liquor, and adding a salt to the black liquor in an amount sufficient to reduce the viscosity thereof. Preferred salts are thiocyanate salts. The black liquor is then oxidized to produce a green liquor and a causticizer added to the green liquor to produce a white liquor containing the sodium-based salts to be recycled. The white liquor is then returned to the digester.
    Type: Grant
    Filed: May 30, 1997
    Date of Patent: May 4, 1999
    Assignee: North Carolina State University
    Inventors: Richard J. Spontak, Joanna E. Roberts, Victoria A. Prevysh, Saad A Khan
  • Patent number: 5869435
    Abstract: A method of fracturing a subterranean formation which surrounds a well bore comprises the steps of providing a fracturing fluid, and injecting the fracturing fluid into the well bore at a pressure sufficient to form fractures in the subterranean formation which surrounds the well bore. The pressure is then released from the fracturing fluid, after which the fluid may be removed from the well and the well placed into production. The fracturing fluid comprises an aqueous liquid, a polysaccharide soluble or dispersible in the aqueous liquid in an amount sufficient to increase the viscosity of the aqueous liquid, an enzyme breaker which degrades said polysaccharide at a temperature above 180.degree. F. Fracturing fluid compositions and enzyme breaker systems useful for carrying out the invention are also disclosed.
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: February 9, 1999
    Assignees: The Trustees of Princeton University, North Carolina State University
    Inventors: Robert M. Kelly, Saad A. Khan, Pascal Leduc, Akash Tayal, Robert K. Prud'homme
  • Patent number: 5635027
    Abstract: A method of recycling sodium-based salts used for digesting wood in a digester during the manufacture of pulp and paper. The method comprises collecting a black liquor from the digester, concentrating the black liquor, and adding a salt to the black liquor in an amount sufficient to reduce the viscosity thereof. Preferred salts are thiocyanate salts. The black liquor is then oxidized to produce a green liquor and a causticizer added to the green liquor to produce a white liquor containing the sodium-based salts to be recycled. The white liquor is then returned to the digester.
    Type: Grant
    Filed: April 3, 1995
    Date of Patent: June 3, 1997
    Assignee: North Carolina State University
    Inventors: Richard J. Spontak, Joanna E. Roberts, Victoria A. Prevysh, Saad A. Khan
  • Patent number: 5421412
    Abstract: A method of fracturing a subterranean formation which surrounds a well bore comprises the steps of providing a fracturing fluid, and injecting the fracturing fluid into the well bore at a pressure sufficient to form fractures in the subterranean formation which surrounds the well bore. The pressure is then released from the fracturing fluid, after which the fluid may be removed from the well and the well placed into production. The fracturing fluid comprises an aqueous liquid, a polysaccharide soluble or dispersible in the aqueous liquid in an amount sufficient to increase the viscosity of the aqueous liquid, an enzyme breaker which degrades said polysaccharide at a temperature above 180.degree. F. Fracturing fluid compositions and enzyme breaker systems useful for carrying out the invention are also disclosed.
    Type: Grant
    Filed: March 10, 1994
    Date of Patent: June 6, 1995
    Assignee: North Carolina State University
    Inventors: Robert M. Kelly, Saad A. Khan, Pascal Leduc, Akash Tayal, Robert K. Prud'homme
  • Patent number: 5105655
    Abstract: A rheological device suitable for measuring the rate of polymerization of ultraviolet sensitive polymers includes a part of open-ended cylindrical fixtures having removable quartz windows at one end. The upper fixture is adapted with a window which permits light to enter and impinge upon the surface of an elliptically-shaped mirror. Curing is monitored by measuring the elastic and viscous moduli during polymerization.
    Type: Grant
    Filed: January 18, 1991
    Date of Patent: April 21, 1992
    Assignee: Bell Communications Research, Inc.
    Inventors: Saad A. Khan, Gabor D. Kiss, Kirk J. Mikkelsen