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).
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Patent number: 10253420Abstract: 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: GrantFiled: May 30, 2017Date of Patent: April 9, 2019Assignee: DNV GL ASInventors: Yumei Zhai, Shan Guan, Narasi Sridhar, Arun S. Agarwal
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Publication number: 20170292196Abstract: 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: ApplicationFiled: May 30, 2017Publication date: October 12, 2017Applicant: DNV GL ASInventors: Yumei Zhai, Shan Guan, Narasi Sridhar, Arun S. Agarwal
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Publication number: 20150354070Abstract: 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: ApplicationFiled: August 19, 2015Publication date: December 10, 2015Applicant: DET NORSKE VERITAS (U.S.A.), INC.Inventors: Shan Guan, Narasi Sridhar, Arun S. Agarwal
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Patent number: 9145615Abstract: 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: GrantFiled: September 22, 2011Date of Patent: September 29, 2015Inventors: Yumei Zhai, Feng Gui, Shan Guan, Narasi Sridhar, Arun S. Agarwal
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Publication number: 20130186771Abstract: 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: ApplicationFiled: September 22, 2011Publication date: July 25, 2013Applicant: DET NORSKE VERITAS ASInventors: Shan Guan, Narasi Sridhar, Arun S. Agarwal, Feng Gui
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Patent number: 6987396Abstract: 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: GrantFiled: January 26, 2004Date of Patent: January 17, 2006Assignee: Southwest Research InstituteInventors: Lietai Yang, Narasi Sridhar
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Publication number: 20040155670Abstract: 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: ApplicationFiled: January 26, 2004Publication date: August 12, 2004Inventors: Lietai Yang, Narasi Sridhar
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Patent number: 6772622Abstract: 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: GrantFiled: March 8, 2002Date of Patent: August 10, 2004Assignee: Southwest Research InstituteInventors: Oliver C. Moghissi, Darrell S. Dunn, Narasi Sridhar
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Patent number: 6683463Abstract: 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: GrantFiled: March 26, 2002Date of Patent: January 27, 2004Assignee: Southwest Research InstituteInventors: Lietai Yang, Narasi Sridhar
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Publication number: 20020194905Abstract: 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: ApplicationFiled: March 8, 2002Publication date: December 26, 2002Applicant: SOUTHWEST RESEARCH INSTITUTEInventors: Oliver C. Moghissi, Darrell S. Dunn, Narasi Sridhar
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Publication number: 20020153907Abstract: 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: ApplicationFiled: March 26, 2002Publication date: October 24, 2002Inventors: Lietai Yang, Narasi Sridhar
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Patent number: 6063517Abstract: 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: GrantFiled: October 16, 1997Date of Patent: May 16, 2000Assignee: Southwest Research InstituteInventors: Alan Montemayor, Edward Albert Bass, Michael Stewart, Narasi Sridhar
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Patent number: 5063023Abstract: 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: GrantFiled: November 17, 1989Date of Patent: November 5, 1991Assignee: Haynes International, Inc.Inventor: Narasi Sridhar
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Patent number: 4816085Abstract: 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: GrantFiled: August 14, 1987Date of Patent: March 28, 1989Assignee: Haynes International, Inc.Inventors: Lee H. Flasche, Narasi Sridhar
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Patent number: 4678523Abstract: 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: GrantFiled: July 3, 1986Date of Patent: July 7, 1987Assignee: Cabot CorporationInventors: Narasi Sridhar, Paul Crook