Patents by Inventor Narasi Sridhar

Narasi Sridhar 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: 10253420
    Abstract: A process is provided for electrochemical reduction, particularly the electrochemical reduction of carbon dioxide to formate. According one embodiment, an electrochemical process includes the electrochemical reduction of carbon dioxide to formate utilizing periodic pulsed anodic polarization, periodic pulsed deep cathodic polarization, or combinations thereof to remove cathodic deposits. Various polarization techniques are disclosed which improve overall Faradaic Efficiency.
    Type: Grant
    Filed: May 30, 2017
    Date of Patent: April 9, 2019
    Assignee: DNV GL AS
    Inventors: Yumei Zhai, Shan Guan, Narasi Sridhar, Arun S. Agarwal
  • Publication number: 20170292196
    Abstract: A process is provided for electrochemical reduction, particularly the electrochemical reduction of carbon dioxide to formate. According one embodiment, an electrochemical process includes the electrochemical reduction of carbon dioxide to formate utilizing periodic pulsed anodic polarization, periodic pulsed deep cathodic polarization, or combinations thereof to remove cathodic deposits. Various polarization techniques are disclosed which improve overall Faradaic Efficiency.
    Type: Application
    Filed: May 30, 2017
    Publication date: October 12, 2017
    Applicant: DNV GL AS
    Inventors: Yumei Zhai, Shan Guan, Narasi Sridhar, Arun S. Agarwal
  • Publication number: 20150354070
    Abstract: A process and apparatus are provided for the electrochemical reduction of carbon dioxide to formate. According one embodiment, an electrochemical process includes the catalytic electro-chemical reduction of carbon dioxide to formate utilizing a cathodic catalyst comprising tin and zinc, the zinc comprising between three and six weight percent of the catalyst. In a further embodiment, an electrochemical reactor for the electrochemical reduction of carbon dioxide to formate comprises a cathodic catalyst comprising tin and zinc, the zinc comprising between three and six weight percent of the catalyst.
    Type: Application
    Filed: August 19, 2015
    Publication date: December 10, 2015
    Applicant: DET NORSKE VERITAS (U.S.A.), INC.
    Inventors: Shan Guan, Narasi Sridhar, Arun S. Agarwal
  • Patent number: 9145615
    Abstract: A method and apparatus is provided for the electrochemical reduction of carbon dioxide to formate and formic acid. One embodiment features a three-compartment reactor which houses: a gas compartment; a catholyte compartment, which contains a porous cathode having a tin-based catalyst; and an anolyte compartment, which contains an anode having a mixed metal oxide catalyst. Further embodiments include a method for depositing tin onto a porous cathode, tin-zinc cathodes, a reaction method using an acidic anolyte, and pulsed polarization to extend reactor runtimes.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: September 29, 2015
    Inventors: Yumei Zhai, Feng Gui, Shan Guan, Narasi Sridhar, Arun S. Agarwal
  • Publication number: 20130186771
    Abstract: A method and apparatus is provided for the electrochemical reduction of carbon dioxide to formate and formic acid. One embodiment features a three-compartment reactor which houses: a gas compartment; a catholyte compartment, which contains a porous cathode having a tin-based catalyst; and an anolyte compartment, which contains an anode having a mixed metal oxide catalyst. Further embodiments include a method for depositing tin onto a porous cathode, tin zinc cathodes, a reaction method using an acidic anolyte, and pulsed polarization to extend reactor runtimes.
    Type: Application
    Filed: September 22, 2011
    Publication date: July 25, 2013
    Applicant: DET NORSKE VERITAS AS
    Inventors: Shan Guan, Narasi Sridhar, Arun S. Agarwal, Feng Gui
  • Patent number: 6987396
    Abstract: A sensor array for measuring localized corrosion based on electrochemical reactions is disclosed. The sensor has an array of electrodes that are made from the material of interest. The electrodes are electrically insulated from each other and arranged so that a small area of the electrode contacts a corrosive environment. The voltage outputs across the electrodes connected to the electrodes are measured and used as the signals to indicate localized corrosion.
    Type: Grant
    Filed: January 26, 2004
    Date of Patent: January 17, 2006
    Assignee: Southwest Research Institute
    Inventors: Lietai Yang, Narasi Sridhar
  • Publication number: 20040155670
    Abstract: A sensor array for measuring localized corrosion based on electrochemical reactions is disclosed. The sensor has an array of electrodes that are made from the material of interest. The electrodes are electrically insulated from each other and arranged so that a small area of the electrode contacts a corrosive environment. The voltage outputs across the electrodes connected to the electrodes are measured and used as the signals to indicate localized corrosion.
    Type: Application
    Filed: January 26, 2004
    Publication date: August 12, 2004
    Inventors: Lietai Yang, Narasi Sridhar
  • Patent number: 6772622
    Abstract: A coupon for monitoring cathodic protection includes a metallic coupon structure on the outer surface of which at least one type of coating disbondment geometry anticipated on a pipeline is fabricated.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: August 10, 2004
    Assignee: Southwest Research Institute
    Inventors: Oliver C. Moghissi, Darrell S. Dunn, Narasi Sridhar
  • Patent number: 6683463
    Abstract: A sensor array for measuring localized corrosion based on electrochemical reactions is disclosed. The sensor has an array of electrodes that are made from the material of interest. The electrodes are electrically insulated from each other and arranged so that a small area of the electrode contacts a corrosive environment. The voltage outputs across the electrodes connected to the electrodes are measured and used as the signals to indicate localized corrosion.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: January 27, 2004
    Assignee: Southwest Research Institute
    Inventors: Lietai Yang, Narasi Sridhar
  • Publication number: 20020194905
    Abstract: A coupon for monitoring cathodic protection includes a metallic coupon structure on the outer surface of which at least one type of coating disbondment geometry anticipated on a pipeline is fabricated.
    Type: Application
    Filed: March 8, 2002
    Publication date: December 26, 2002
    Applicant: SOUTHWEST RESEARCH INSTITUTE
    Inventors: Oliver C. Moghissi, Darrell S. Dunn, Narasi Sridhar
  • Publication number: 20020153907
    Abstract: A sensor array for measuring localized corrosion based on electrochemical reactions is disclosed. The sensor has an array of electrodes that are made from the material of interest. The electrodes are electrically insulated from each other and arranged so that a small area of the electrode contacts a corrosive environment. The voltage outputs across the electrodes connected to the electrodes are measured and used as the signals to indicate localized corrosion.
    Type: Application
    Filed: March 26, 2002
    Publication date: October 24, 2002
    Inventors: Lietai Yang, Narasi Sridhar
  • Patent number: 6063517
    Abstract: A pre-spiral bundle for making a spiral wrapped cylindrical fuel cell and cylindrical fuel cells made using the pre-spiral bundle. The pre-spiral bundle comprises a sleeve defining a hydrogen flowpath. The sleeve comprises a proton exchange membrane encapsulating a substantially planar anode in ionic communication with a catalytically effective amount of a noble metal catalyst. A first hydrogen inlet comprises a first edge of the sleeve and a second hydrogen inlet comprises an opposed, substantially parallel edge of the sleeve. The hydrogen flowpath is defined by the anode. A cylindrical fuel cell is made by abutting a flexible, porous cathode to the sleeve in ionic communication with a noble metal catalyst and wrapping the sleeve and the cathode around one of the hydrogen inlets.
    Type: Grant
    Filed: October 16, 1997
    Date of Patent: May 16, 2000
    Assignee: Southwest Research Institute
    Inventors: Alan Montemayor, Edward Albert Bass, Michael Stewart, Narasi Sridhar
  • Patent number: 5063023
    Abstract: Disclosed is a nickel-base alloy for use under "super oxidizing" environments, for example, concentrated sulfuric acid, fuming nitric acid, chromium acid and mixtures containing chromic acid. The alloy has good strength and may be precipitation hardened. Its thermal stability and weldability are excellent. The alloy has a high degree of resistance to pitting. A nominal composition contains, in percent by weight, about 20 chromium, about 2 copper, about 2 iron, about 2 molybdenum, about 5 silicon and the balance nickel plus normal impurities.
    Type: Grant
    Filed: November 17, 1989
    Date of Patent: November 5, 1991
    Assignee: Haynes International, Inc.
    Inventor: Narasi Sridhar
  • Patent number: 4816085
    Abstract: Disclosed is a duplex stainless steel containing about 25% chromium, about 2% copper, about 3% molybdenum, about 0.2% nitrogen, about 9% nickel and the balance iron plus modifying elements and impurities. In corrosion conditions, including severe pitting environments, the steel contains up to 3%, and preferably 0.2 to 1.0% niobium. The alloy is especially suited for use as a welding filler material. The steel, after welding, has improved Charpy impact properties, increased tensile ductility and corrosion resistance. The steel is also suited for use in the form of cast, wrought or powder products.
    Type: Grant
    Filed: August 14, 1987
    Date of Patent: March 28, 1989
    Assignee: Haynes International, Inc.
    Inventors: Lee H. Flasche, Narasi Sridhar
  • Patent number: 4678523
    Abstract: Disclosed is a "duplex" stainless steel especially suited for use in conditions requiring a high degree of wear and corrosion resistance; for example structural fasteners, such as nuts and bolts as used in chemical processing. The alloy typically contains, in weight percent, 12 cobalt, 20 chromium, 11 nickel, 5 silicon, 1.5 molybdenum, 2 copper, up to 0.2 nitrogen and up to 0.01 carbon. The "duplex" structure preferably consists of about 30% ferrite and the balance essentially austenite.
    Type: Grant
    Filed: July 3, 1986
    Date of Patent: July 7, 1987
    Assignee: Cabot Corporation
    Inventors: Narasi Sridhar, Paul Crook