Patents by Inventor Amitava Gupta

Amitava Gupta 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).

  • Double-beam optical method and apparatus for measuring thermal diffusivity and other molecular dynamic processes in utilizing the transient thermal lens effect
    Patent number: 4243327
    Abstract: A method and apparatus for measuring thermal diffusivity and molecular relaxation processes in a sample material utilizing two light beams, one being a pulsed laser light beam for forming a thermal lens in the sample material, and the other being a relatively low power probe light beam for measuring changes in the refractive index of the sample material during formation and dissipation of the thermal lens. More specifically, a sample material is irradiated by relatively high power, short pulses from a dye laser. Energy from the pulses is absorbed by the sample material, thereby forming a thermal lens in the area of absorption. The pulse repetition rate is chosen so that the thermal lens is substantially dissipated by the time the next pulse reaches the sample material. A probe light beam, which in a specific embodiment is a relatively low power, continuous wave (cw) laser beam, irradiates the thermal lens formed in the sample material.
    Type: Grant
    Filed: January 31, 1979
    Date of Patent: January 6, 1981
    Inventors: Robert A. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Frosch, Jovan Moacanin, Amitava Gupta, Su-don Hong
  • Polyvinyl pyridine microspheres
    Patent number: 4224359
    Abstract: Microspheres are produced by cobalt gamma radiation initiated polymerization of a dilute aqueous vinyl pyridine solution. Addition of cross-linking agent provides higher surface area beads. Addition of monomers such as hydroxyethylmethacrylate acrylamide or methacrylamide increases hydrophilic properties and surface area of the beads. High surface area catalytic supports are formed in the presence of controlled pore glass substrate.
    Type: Grant
    Filed: October 2, 1978
    Date of Patent: September 23, 1980
    Assignee: California Institute of Technology
    Inventors: Alan Rembaum, Amitava Gupta, Willi Volksen
  • Polyvinyl pyridine microspheres
    Patent number: 4170685
    Abstract: Microspheres are produced by cobalt gamma radiation initiated polymerization of a dilute aqueous vinyl pyridine solution. Addition of cross-linking agent provides higher surface area beads. Addition of monomers such as hydroxyethylmethacrylate acrylamide or methacrylamide increases hydrophilic properties and surface area of the beads. High surface area catalytic supports are formed in the presence of controlled pore glass substrate.
    Type: Grant
    Filed: March 22, 1977
    Date of Patent: October 9, 1979
    Assignee: California Institute of Technology
    Inventors: Alan Rembaum, Amitava Gupta, Willi Volksen
  • Photochemical preparation of olefin addition catalysts
    Patent number: 4127506
    Abstract: Novel polymer supported catalysts are prepared by photo-irradiation of low valent transition metal compounds such as Co.sub.2 (CO).sub.8, Rh.sub.4 (CO).sub.12 or Ru.sub.3 (CO).sub.12 in the presence of solid polymers containing amine ligands such as polyvinyl pyridine. Hydroformylation of olefins to aldehydes at ambient conditions has been demonstrated.
    Type: Grant
    Filed: January 31, 1977
    Date of Patent: November 28, 1978
    Assignee: California Institute of Technology
    Inventors: Harry B. Gray, Alan Rembaum, Amitava Gupta