Patents by Inventor Durga V. Subramanian

Durga V. Subramanian 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).

  • Suppression of antagonistic hydration reactions in blended cements
    Patent number: 8518176
    Abstract: Method for suppressing antagonistic hydration reactions in Portland fly ash cement involves the use of unponded fly ash that is pre-hydrated, preferably as an aqueous slurry wherein fly ash, preferably having an alkaline earth metal oxide of at least 10% by weight, is soaked, whereby the hydration reaction of the resultant mixed fly ash and cement is accelerated when these components are mixed together with water to hydrate the cement. Blended Portland cement/fly ash compositions of the invention will also have higher early strength as well as shorter set time compared to untreated blends.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: August 27, 2013
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Denise A. Silva, Josephine Cheung, Paul Sandberg, Lawrence Roberts, Durga V. Subramanian, John L. Gallagher, Lawrence L. Kuo
  • SUPPRESSION OF ANTAGONISTIC HYDRATION REACTIONS IN BLENDED CEMENTS
    Publication number: 20120298011
    Abstract: Method for suppressing antagonistic hydration reactions in Portland fly ash cement involves the use of unponded fly ash that is pre-hydrated, preferably as an aqueous slurry wherein fly ash, preferably having an alkaline earth metal oxide of at least 10% by weight, is soaked, whereby the hydration reaction of the resultant mixed fly ash and cement is accelerated when these components are mixed together with water to hydrate the cement. Blended Portland cement/fly ash compositions of the invention will also have higher early strength as well as shorter set time compared to untreated blends.
    Type: Application
    Filed: October 30, 2009
    Publication date: November 29, 2012
    Inventors: Denise A. Silva, Josephine Cheung, Paul Sandberg, Lawrence Roberts, Durga V. Subramanian, John L. Gallagher, Lawrence L. Kuo
  • Analysis of aluminum in amino acids by high performance liquid chromatography
    Patent number: 5242834
    Abstract: An analytical method for determining aluminum in amino acids such as glycine. A complex of aluminum and dihydroxyazobenzene is formed by reacting the amino acid solution with a mixture of dihydroxyazobenzene and acetonitrile in the presence of a buffer to obtain a pH of between about 7 and 8. The resulting complex is analyzed for aluminum by high performance liquid chromatography. Minimization of aluminum contamination is achieved by reducing the number of reagents used in the procedure.
    Type: Grant
    Filed: November 14, 1991
    Date of Patent: September 7, 1993
    Assignee: Hampshire Chemical Corp.
    Inventor: Durga V. Subramanian