Patents by Inventor Ramasubramanyam Nagarajan

Ramasubramanyam Nagarajan 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: 11708485
    Abstract: Described herein are treated polymers comprising a polyacrylamide homopolymer or a copolymer thereof having at least 30 mol % acrylamide residue content and a weight average molecular weight in the range of 1×105 g/mol to 1×108 g/mol, and 0.1 wt % to 10 wt % of a C1-C6 alkyl ricinoleate based on the weight of the mixture of polymer and alkyl ricinoleate. The polymers are in powder form and include less than about 30 wt % water based on the powder weight. The treated polymer powders dissolve rapidly in water and develop very little or even no insoluble gel upon diluting with water, even when the water is produced water or connate. The treated polymer solutions are useful for in-the-field rapid dilution for applications such as papermaking, flocculation, beneficiation, wastewater treatment, and enhanced oil recovery.
    Type: Grant
    Filed: August 4, 2020
    Date of Patent: July 25, 2023
    Assignee: Ecolab USA Inc.
    Inventors: Suresh R. Sriram, Ramasubramanyam Nagarajan
  • Patent number: 11359135
    Abstract: Water-in-oil lattices of water soluble polymers and methods of using the same are presented. The lattices are made, used, and stored having about 15 wt % to 70 wt % polymer solids and further include one or more alkyl ricinoleates. We have found that C1-C6 alkyl ricinoleates added to such lattices facilitate rapid and complete dilution to less than or equal to 1 wt % polymer solids in a continuous water phase. In particular under conditions wherein the water source used to invert the latex is provided at low temperature (?10° C. to 10° C.), or includes a high level of total dissolved solids, or is both low temperature and high total dissolved solids.
    Type: Grant
    Filed: August 4, 2020
    Date of Patent: June 14, 2022
    Assignee: Ecolab USA Inc.
    Inventors: Suresh R. Sriram, Ramasubramanyam Nagarajan
  • Publication number: 20210040377
    Abstract: Water-in-oil lattices of water soluble polymers and methods of using the same are presented. The lattices are made, used, and stored having about 15 wt % to 70 wt % polymer solids and further include one or more alkyl ricinoleates. We have found that C1-C6 alkyl ricinoleates added to such lattices facilitate rapid and complete dilution to less than or equal to 1 wt % polymer solids in a continuous water phase. In particular under conditions wherein the water source used to invert the latex is provided at low temperature (?10° C. to 10° C.), or includes a high level of total dissolved solids, or is both low temperature and high total dissolved solids.
    Type: Application
    Filed: August 4, 2020
    Publication date: February 11, 2021
    Inventors: Suresh R. Sriram, Ramasubramanyam Nagarajan
  • Publication number: 20210040306
    Abstract: Described herein are treated polymers comprising a polyacrylamide homopolymer or a copolymer thereof having at least 30 mol % acrylamide residue content and a weight average molecular weight in the range of 1×105 g/mol to 1×108 g/mol, and 0.1 wt % to 10 wt % of a C1-C6 alkyl ricinoleate based on the weight of the mixture of polymer and alkyl ricinoleate. The polymers are in powder form and include less than about 30 wt % water based on the powder weight. The treated polymer powders dissolve rapidly in water and develop very little or even no insoluble gel upon diluting with water, even when the water is produced water or connate. The treated polymer solutions are useful for in-the-field rapid dilution for applications such as papermaking, flocculation, beneficiation, wastewater treatment, and enhanced oil recovery.
    Type: Application
    Filed: August 4, 2020
    Publication date: February 11, 2021
    Inventors: Suresh R. Sriram, Ramasubramanyam Nagarajan
  • Patent number: 8851059
    Abstract: The present invention provides a self-cleaning wiresaw cutting apparatus including a cleaning mechanism adapted to clean the components of the wiresaw before, during, or after a cutting process or to humidify the cutting region of the apparatus. The apparatus contains at least one dispenser adapted to dispense an aqueous fluid onto various components of the wiresaw.
    Type: Grant
    Filed: March 30, 2010
    Date of Patent: October 7, 2014
    Assignee: Cabot Microelectronics Corporation
    Inventors: Steven Grumbine, Carlos Barros, Ramasubramanyam Nagarajan
  • Patent number: 8636560
    Abstract: The invention provides a method and apparatus for removing magnetic or magnetized contaminants from a wiresaw cutting slurry during a wiresaw cutting process. The apparatus comprises a recirculating slurry dispensing system that defines the slurry flow pathway. The recirculating dispensing slurry system comprises a magnetic separator for removing magnetic or magnetizable contaminants from the slurry, wherein the purified slurry is discharged back into recirculation within the recirculating slurry dispensing system.
    Type: Grant
    Filed: December 21, 2009
    Date of Patent: January 28, 2014
    Assignee: Cabot Microelectronics Corporation
    Inventors: Steven Grumbine, Ramasubramanyam Nagarajan
  • Patent number: 8157876
    Abstract: A wiresaw cutting fluid composition of the present invention comprises about 25 to about 75% by weight of a particulate abrasive suspended in an aqueous carrier containing a polymeric viscosity modifier that comprises a polymer including a majority of non-ionic monomer units (preferably 100 mol % non-ionic monomer units), has a number average molecular weight (Mn) of at least about 5 kDa, and is present in the composition at a concentration sufficient to provide a Brookfield viscosity for the composition in the range of about 50 to about 1000 cP, e.g., 50 to about 700 cP, at about 25° C. at a spindle rotation rate of about 60 rpm. In one embodiment, the viscosity modifier comprises a polymer having a weight average molecular weight (Mw) of at least about 200 kDa. When a viscosity modifier of 200 kDa or greater Mw is utilized, a preferred wiresaw cutting method the cutting fluid is circulated and applied by pumps and nozzles operating at a relatively low shear rate of not more than about 104 s?1.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: April 17, 2012
    Assignee: Cabot Microelectronics Corporation
    Inventors: Steven Grumbine, Chul Woo Nam, William Ward, Ramasubramanyam Nagarajan
  • Publication number: 20120006312
    Abstract: The present invention provides a self-cleaning wiresaw cutting apparatus including a cleaning mechanism adapted to clean the components of the wiresaw before, during, or after a cutting process or to humidify the cutting region of the apparatus. The apparatus contains at least one dispenser adapted to dispense an aqueous fluid onto various components of the wiresaw.
    Type: Application
    Filed: March 30, 2010
    Publication date: January 12, 2012
    Inventors: Steven Grumbine, Carlo Barros, Ramasubramanyam Nagarajan
  • Publication number: 20110240001
    Abstract: The invention provides a method and apparatus for removing magnetic or magnetized contaminants from a wiresaw cutting slurry during a wiresaw cutting process. The apparatus comprises a recirculating slurry dispensing system that defines the slurry flow pathway. The recirculating dispensing slurry system comprises a magnetic separator for removing magnetic or magnetizable contaminants from the slurry, wherein the purified slurry is discharged back into recirculation within the recirculating slurry dispensing system.
    Type: Application
    Filed: December 21, 2009
    Publication date: October 6, 2011
    Inventors: Steven Grumbine, Ramasubramanyam Nagarajan
  • Publication number: 20090126713
    Abstract: A wiresaw cutting fluid composition of the present invention comprises about 25 to about 75% by weight of a particulate abrasive suspended in an aqueous carrier containing a polymeric viscosity modifier that comprises a polymer including a majority of non-ionic monomer units (preferably 100 mol % non-ionic monomer units), has a number average molecular weight (Mn) of at least about 5 kDa, and is present in the composition at a concentration sufficient to provide a Brookfield viscosity for the composition in the range of about 50 to about 1000 cP, e.g., 50 to about 700 cP, at about 25° C. at a spindle rotation rate of about 60 rpm. In one embodiment, the viscosity modifier comprises a polymer having a weight average molecular weight (Mw) of at least about 200 kDa. When a viscosity modifier of 200 kDa or greater Mw is utilized, a preferred wiresaw cutting method the cutting fluid is circulated and applied by pumps and nozzles operating at a relatively low shear rate of not more than about 104 s?1.
    Type: Application
    Filed: December 19, 2008
    Publication date: May 21, 2009
    Inventors: Steven Grumbine, Chul Woo Nam, William Ward, Ramasubramanyam Nagarajan
  • Patent number: 6238521
    Abstract: A papermaking process consisting essentially of: forming an aqueous cellulosic papermaking slurry; adding to the slurry certain additives, with said certain additives selected from the group including: coagulants; sizing agents; and mineral fillers; draining the slurry to form a sheet; and drying the sheet to form a paper sheet; the improvement comprising adding to the slurry, prior to it being drained; an effective amount of a cationic dispersion polymer; which cationic dispersion polymer is a copolymer comprising about 30 mole % diallyldimethylammonium chloride (DADMAC) and about 70 mole % acrylamide (AcAm); and adding to the slurry, either before or after said cationic dispersion polymer is added and the slurry is drained, a microparticle selected from the group consisting of a) copolymers of acrylic acid and acrylamide; b) bentonite; and c) dispersed silica; with the proviso that said coagulant cannot be a cationic dispersion copolymer comprising about 30 mole % diallyldimethylammonium chloride
    Type: Grant
    Filed: May 21, 1999
    Date of Patent: May 29, 2001
    Assignee: Nalco Chemical Company
    Inventors: Jane B. Wong Shing, Chidambaram Maltesh, Ramasubramanyam Nagarajan
  • Patent number: 6071379
    Abstract: A method for improving retention and drainage performance in a papermaking process is disclosed. The method comprises forming an aqueous cellulosic papermaking slurry, adding an effective amount of a hydrophilic dispersion polymer to the slurry, draining the slurry to form a sheet and drying the sheet. The hydrophilic dispersion polymer is preferably a copolymer of diallyldimethyl ammonium chloride and acrylamide.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: June 6, 2000
    Assignee: Nalco Chemical Company
    Inventors: Jane B. Wong Shing, John R. Hurlock, Chidambaram Maltesh, Ramasubramanyam Nagarajan