Patents by Inventor Abolghassem Y. Tehrani

Abolghassem Y. Tehrani 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).

  • Method of making a frit
    Patent number: 4966696
    Abstract: To reduce tailing, the frit at the outlet to the liquid chromatographic column has a diameter substantially equal to that of the inside diameter of the outlet end of the column and less than two millimeters. It is held directly against the packing of the column within a cylindrical member having a shoulder with a central aperture at least the size of the diameter of the frit and cylindrical walls which are fastened to resist force in the direction of the axis of the column from its inlet to its outlet. A gasket seals the cylindrical holder against the column wall. The frit is formed of gold-plated nickel spheres sintered together at temperature lower than the gold-nickel eutectic temperature of 950 degrees Celsius but above the phase-immiscibility temperature of 720 degrees Celsius. The size and shape of the frit is selected to reduce tailing by causing the flow path from the column to be uniform.
    Type: Grant
    Filed: June 16, 1989
    Date of Patent: October 30, 1990
    Assignee: Isco, Inc.
    Inventors: Robert W. Allington, Abolghassem Y. Tehrani, John N. Jones
  • Apparatus for reducing tailing in a liquid chromatograph
    Patent number: 4863592
    Abstract: To reduce tailing, the frit at the outlet to the liquid chromatographic column has a diameter substantially equal to that of the inside diameter of the outlet end of the column and less than two millimeters. It is held directly against the packing of the column within a cylindrical member having a shoulder with a central aperture at least the size of the diameter of the frit and cylindrical walls which are fastened to resist force in the direction of the axis of the column from its inlet to its outlet. A gasket seals the cylindrical holder against the column wall. The frit is formed of gold-plated nickel spheres sintered together at a temperature lower than the gold-nickel eutectic temperature of 950 degrees Celsius but above the phase-immiscibility temperature of 720 degrees Celsius. The size and shape of the frit is selected to reduce tailing by causing the flow path from the column to be uniform.
    Type: Grant
    Filed: October 28, 1987
    Date of Patent: September 5, 1989
    Assignee: Isco, Inc.
    Inventors: Robert W. Allington, Abolghassem Y. Tehrani, John N. Jones
  • Apparatus for reducing tailing in a liquid chromatograph
    Patent number: 4765890
    Abstract: To reduce tailing, the frit at the outlet to the liquid chromatographic column has a diameter substantially equal to that of the inside diameter of the outlet end of the column and less than two millimeters. It is held directly against the packing of the column within a cylindrical member having a shoulder with a central aperture at least the size of the diameter of the frit and cylindrical walls which are fastened to resist force in the direction of the axis of the column from its inlet to its outlet. A gasket seals the cylindrical holder against the column wall. The frit is formed of gold-plated nickel spheres sintered together at a temperature lower than the gold-nickel eutectic temperature of 950 degrees Celsius but above the phase-immiscibility temperature of 720 degrees Celsius. The size and shape of the frit is selected to reduce tailing by causing the flow path from the column to be uniform.
    Type: Grant
    Filed: October 5, 1987
    Date of Patent: August 23, 1988
    Assignee: Isco, Inc.
    Inventors: Abolghassem Y. Tehrani, John N. Jones, Robert W. Allington
  • Apparatus for reducing tailing in a liquid chromatograph
    Patent number: 4759843
    Abstract: To reduce tailing, the frit at the outlet to the liquid chromatographic column has a diameter substantially equal to that of the inside diameter of the outlet end of the column and less than two millimeters. It is held directly against the packing of the column within a cylindrical member having a shoulder with a central aperture at least the size of the diameter of the frit and cylindrical walls which are fastened to resist force in the direction of the axis of the column from its inlet to its outlet. A gasket seals the cylindrical holder against the column wall. The frit is formed of gold-plated nickel spheres sintered together at a temperature lower than the gold-nickel eutectic temperature of 950 degrees Celsius but above the phase-immiscibility temperature of 720 degrees Celsius. The size and shape of the frit is selected to reduce tailing by causing the flow path from the column to be uniform.
    Type: Grant
    Filed: October 5, 1987
    Date of Patent: July 26, 1988
    Assignee: Isco, Inc.
    Inventors: Robert W. Allington, Abolghassem Y. Tehrani, John N. Jones
  • Apparatus for reducing tailing in a liquid chromatograph
    Patent number: 4545904
    Abstract: To reduce tailing, the frit at the outlet to the liquid chromatographic column has a diameter substantially equal to that of the inside diameter of the outlet end of the column and less than 2 millimeters. It is held directly against the packing of the column within a cylindrical member having a shoulder with a central aperture at least the size of the diameter of the frit and cylindrical walls which are fastened to resist force in the direction of the axis of the column from its inlet to its outlet. A gasket seals the cylindrical holder against the column wall.
    Type: Grant
    Filed: March 1, 1984
    Date of Patent: October 8, 1985
    Assignee: ISCO, Inc.
    Inventors: Abolghassem Y. Tehrani, John N. Jones, Robert W. Allington