Patents by Inventor V. Subramanian

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).

  • Patent number: 6395107
    Abstract: Processes for producing gray cast iron and the resulting gray cast iron exhibiting consistently good surface finish with prolonged tool life during finish machining with cubic boron nitride and silicon nitride cutting tools at high cutting speeds and low feed rates are provided comprising (1) adding microalloying elements with strong affinity for nitrogen to a gray iron melt; (2) adding microalloying elements with strong affinity for carbon to said melt; and (3) adding microalloying elements with strong affinity for oxygen to said melt, to form a chemically stable, high melting or refractory oxide protective layer at the cutting edge of the tool during metal cutting, thereby suppressing chemical wear.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: May 28, 2002
    Inventor: Sundaresa V. Subramanian
  • Publication number: 20020036033
    Abstract: Processes for producing gray cast iron and the resulting gray cast iron exhibiting consistently good surface finish with prolonged tool life during finish machining with cubic boron nitride and silicon nitride cutting tools at high cutting speeds and low feed rates are provided comprising (1) adding microalloying elements with strong affinity for nitrogen to a gray iron melt; (2) adding microalloying elements with strong affinity for carbon to said melt; and (3) adding microalloying elements with strong affinity for oxygen to said melt, to form a chemically stable, high melting or refractory oxide protective layer at the cutting edge of the tool during metal cutting, thereby suppressing chemical wear.
    Type: Application
    Filed: September 24, 2001
    Publication date: March 28, 2002
    Inventor: Sundaresa V. Subramanian
  • Patent number: 5591007
    Abstract: A turbine airfoil includes a plurality of internal ribs defining at least two independent serpentine cooling circuits arranged in part in different longitudinal tiers, with an outer tier circuit being disposed in part longitudinally above an inner tier circuit for differentially longitudinally cooling the airfoil.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: January 7, 1997
    Assignee: General Electric Company
    Inventors: Ching-Pang Lee, Sundaresa V. Subramanian, George A. Durgin
  • Patent number: 5468690
    Abstract: A slurry for joining metallic or ceramic surfaces or for coating metallic or ceramic and refractory surfaces, comprising a liquid suspending medium and at least two constituents in particulate form suspended in the medium, the constituents being so selected and proportioned as to undergo combustion synthesis when ignited. A method for coating or joining metallic or ceramic surfaces comprises applying such a slurry to a surface to be coated or to surfaces to be joined, and igniting the slurry to cause combustion synthesis.
    Type: Grant
    Filed: February 15, 1994
    Date of Patent: November 21, 1995
    Assignee: University of Cincinnati
    Inventors: Jainagesh A. Sekhar, V. Subramanian, Necip S. Canarslan
  • Patent number: 5376421
    Abstract: A slurry for joining metallic or ceramic surfaces or for coating metallic or ceramic and refractory surfaces, comprising a liquid suspending medium and at least two constituents in particulate form suspended in the medium, the constituents being so selected and proportioned as to undergo combustion synthesis when ignited. A method for coating or joining metallic or ceramic surfaces comprises applying such a slurry to a surface to be coated or to surfaces to be joined, and igniting the slurry to cause combustion synthesis.
    Type: Grant
    Filed: November 25, 1992
    Date of Patent: December 27, 1994
    Assignee: University of Cincinnati
    Inventors: Jainagesh A. Sekhar, V. Subramanian, Necip S. Canarslan
  • Patent number: 5340014
    Abstract: A slurry for joining metallic or ceramic surfaces or for coating metallic or ceramic and refractory surfaces, comprising a liquid suspending medium and at least two constituents in particulate form suspended in the medium, the constituents being so selected and proportioned as to undergo combustion synthesis when ignited. A method for coating or joining metallic or ceramic surfaces comprises applying such a slurry to a surface to be coated or to surfaces to be joined, and igniting the slurry to cause combustion synthesis.
    Type: Grant
    Filed: November 25, 1992
    Date of Patent: August 23, 1994
    Assignee: University of Cincinnati
    Inventors: Jainagesh A. Sekhar, V. Subramanian, Necip S. Canarslan
  • 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
  • Patent number: 4806157
    Abstract: A process for producing compacted graphite cast iron thin walled shaped castings in a high productivity line is provided which comprises: (i) forming a near eutectic melt of cast iron, having a low sulfur content, preferably around 0.01% by weight; (ii) adding to the melt sufficient graphite stabilizing agents such as silicon to suppress the carbide eutectic formation at the large undercooling characteristic of thinner sections of the castings; (iii) admixing at least one rare earth containing additive with said melt to form rare earth compounds so as to reduce and maintain the Henrian oxygen activity in the melt at about 10.sup.-6 ; (iv) inoculating the melt in an optimum manner to promote the required degree of interconnected vermicular graphite growth, and (v) casting the resulting melt.
    Type: Grant
    Filed: December 19, 1984
    Date of Patent: February 21, 1989
    Inventor: Sundaresa V. Subramanian
  • Patent number: 4272346
    Abstract: Carbon fibers are electrocoated by electrodeposition or electropolymerization to facilitate the formation of char, a nonconductive residue or fiber clumps when the coated fibers within a composite are subsequently exposed to fire. Coating materials or precursors are phosphorus compounds, titanates, polyimides, polyquinoxalines, nitriles, or boric acid.
    Type: Grant
    Filed: December 3, 1979
    Date of Patent: June 9, 1981
    Assignee: Washington State University Research Foundation
    Inventors: James J. Jakubowski, Ravanasamudram V. Subramanian
  • Patent number: 4227924
    Abstract: Process for producing vermicular cast iron comprising: (i) forming a near eutectic melt having a sulfur content preferably less than about 0.025% by weight; (ii) admixing at least one rare earth-containing additive with said melt to form stable rare earth oxysulfides thereby reducing and maintaining the Henrian sulfur activity in the melt at between about 0.004 and 0.035; and (iii) thereafter, allowing said melt to solidify.
    Type: Grant
    Filed: May 18, 1978
    Date of Patent: October 14, 1980
    Assignee: Microalloying International, Inc.
    Inventors: Sundaresa V. Subramanian, Debabrata S. Ghosh, John M. Gray, David A. R. Kay, Gary R. Purdy
  • Patent number: 4149866
    Abstract: A method of improving the tensile strength of drawn fibers produced from molten basalt rock. Strength is increased by reducing the ferric iron content of the final fibers below that which would be present in the fibers if drawn under normal atmospheric and operational conditions. This is accomplished by either adding a reducing agent to the melt, by drawing the fibers in an inert or reducing atmosphere, or by a combination of both methods.
    Type: Grant
    Filed: March 9, 1978
    Date of Patent: April 17, 1979
    Assignee: Washington State University Research Foundation
    Inventors: Helen F. Austin, Ravanasamudram V. Subramanian