Patents by Inventor Sivaram Krishnan
Sivaram Krishnan 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: 6324643Abstract: A two level branch prediction system and method is disclosed for controlling instruction flow in a pipelined processor. A first prediction indicator associated with a branch instruction specifies whether a particular branch condition is likely to be satisfied. A second prediction indicator associated with a branch control instruction specifies whether a particular branch target instruction is likely to be needed by one or more of the branch instructions. The first prediction indicator is used to load branch target instructions as they are needed in response to decoding a branch instruction, while the second prediction indicator is used by prefetching logic within the processor to determine whether a particular branch target instruction should be speculatively loaded even before the associated branch instruction is executed.Type: GrantFiled: October 4, 2000Date of Patent: November 27, 2001Assignee: Hitachi, Ltd.Inventors: Sivaram Krishnan, Sebastian Haviuj Ziesler
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Patent number: 6197854Abstract: A thermoplastic polycarbonate molding composition having improved resistance to gamma radiation-induced yellowing is disclosed. Particularly suitable for the manufacture of devices targeted for medical applications, the composition contains additive amounts of a first stabilizing compound conforming structurally to wherein in the embodiment where n is 1, R1 is an unsubstituted or substituted carbocyclic or heterocyclic aromatic ring system, and where in the embodiment where n is 2, R1 is unsubstituted or C1-4-alkyl or hydroxy substituted phenylene or naphthylene, and R2, R3, R4 and R5 independently of one another are hydrogen, C1-25-alkyl groups or phenyl. and a saccharine compound.Type: GrantFiled: April 3, 2000Date of Patent: March 6, 2001Assignees: Bayer Corporation, Bayer AktiengesellschaftInventors: Sivaram Krishnan, Wolfgang Ebert
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Patent number: 6197853Abstract: A thermoplastic polycarbonate molding composition having improved resistance to gamma radiation-induced yellowing is disclosed. Particularly suitable for the manufacture of devices geared for medical applications, the composition contains an additive amount of a stabilizing compound conforming structurally to where R1 denotes a C1-30-alkyl group and R2 denotes an aryl radical.Type: GrantFiled: July 1, 1999Date of Patent: March 6, 2001Assignee: Bayer CorporationInventors: Daniel H. Bolton, Sivaram Krishnan, David M. Derikart, James B. Johnson
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Patent number: 6180702Abstract: A thermoplastic molding composition comprising polycarbonate resin and additive, positive, amounts of stabilizer and salt is disclosed. The composition is characterized by its freedom from splay and by its improved flame retardance. The stabilizer of the invention is a physical mixture of poly(alkyl methacrylate) with fluorinated polyolefin, and the salt is an alkali metal or alkaline earth metal salt of perfluoroalkane sulfonic acid, aromatic sulfimide, or aromatic sulfonic acid.Type: GrantFiled: August 9, 1999Date of Patent: January 30, 2001Assignee: Bayer CorporationInventors: James Y. J. Chung, Sivaram Krishnan, Winfried G. Paul
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Patent number: 6166129Abstract: The present invention relates to a novel photochromic polyurethane consisting essentially of an isocyanate reactive mixture consisting essentially of: i) from about 40 to about 85% by weight of one or more polyols having a nominal functionality of from 2 to 4 and molecular weights of from 500 to 6000 g/mole; ii) from about 15 to about 60% by weight of one or more diols or triols or mixtures thereof having a functionality of from 2 to 3 and molecular weights of from 62 to 499; b) an aliphatic polyisocyanate having a functionality ranging from about 2 to about 3; and c) a photochromic compound selected from a group consisting of spirooxazines, fulgides, fulgimides, and naphthopyrans, wherein the photochromic compound is present in an amount of 0.01 to 5 parts per hundred parts by weight of the isocyanate reactive mixture.Type: GrantFiled: October 1, 1999Date of Patent: December 26, 2000Assignee: Bayer CorporationInventors: James W. Rosthauser, Karl W. Haider, Sivaram Krishnan, James N. Rieck
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Patent number: 6153685Abstract: A thermoplastic composition featuring an improved resistance to thermally induced resin degradation is disclosed. The composition comprises (i) thermoplastic polycarbonate resin (ii) about 3 to 20 percent, relative to the total weight of (i) and (ii), of titanium dioxide, and (iii) an oligomer or polymer the structure of which features at least one pendant cyclic iminoether group per molecular chain. The amount of (iii) is that which is sufficient to improve the resistance of the composition to thermal degradation.Type: GrantFiled: September 23, 1998Date of Patent: November 28, 2000Assignee: Bayer CorporationInventors: Sivaram Krishnan, James B. Johnson
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Patent number: 6107375Abstract: A thermoplastic composition featuring an improved resistance to hydrolysis is disclosed. The composition comprises (i) thermoplastic polycarbonate resin (ii) about 0.01 to 3 percent of a compound selected from the group consisting of phosphite and phosphonite and (iii) an additive amount of an oligomer or polymer the structure of which features at least one pendant cyclic iminoether group per molecular chain. The additive amount is that which is sufficient to improve the resistance of the polycarbonate resin to hydrolysis.Type: GrantFiled: October 8, 1998Date of Patent: August 22, 2000Assignee: Bayer CorporationInventors: Sivaram Krishnan, James B. Johnson, Donald K. Booher
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Patent number: 6107395Abstract: The present invention relates to a novel photochromic polyurethane consisting essentially of an isocyanate reactive mixture consisting essentially of: i) from about 40 to about 85% by weight of one or more polyols having a nominal functionality of from 2 to 4 and molecular weights of from 500 to 6000 g/mole; ii) from about 15 to about 60% by weight of one or more diols or triols or mixtures thereof having a functionality of from 2 to 3 and molecular weights of from 62 to 499; b) an aliphatic polyisocyanate having a functionality ranging from about 2 to about 3; and c) a photochromic compound selected from a group consisting of spirooxazines, fulgides, fulgimides, and naphthopyrans, wherein the photochromic compound is present in an amount of 0.01 to 5 parts per hundred parts by weight of the isocyanate reactive mixture.Type: GrantFiled: December 16, 1998Date of Patent: August 22, 2000Assignee: Bayer CorporationInventors: James W. Rosthauser, Karl W. Haider, Sivaram Krishnan, James N. Rieck
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Patent number: 6103777Abstract: A thermoplastic molding composition having low haze values, suitable for optical applications is disclosed. The compositions contains a resinous component selected from the group consisting of (i) a homogeneous blend of polycarbonate resin and polycaprolactone and (ii) a copoly(carbonate-lactone) block or random copolymer, and melanin in an amount of 0.1 to 1.0 parts per hundred parts of weight of the resinous component.Type: GrantFiled: December 18, 1998Date of Patent: August 15, 2000Assignee: Bayer CorporationInventors: Sivaram Krishnan, Robert A. Pyles, James B. Johnson
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Patent number: 6069225Abstract: A thermoplastic polycarbonate composition suitable for the preparation of optical storage devices, for instance optical discs, is disclosed. The composition, containing a stabilizing amount of partially fatty acid ester and as a stabilizer, a compound the structure of which contains at least one benzofuran-2-one group per molecule, features improved resistance to yellowing, reduced haze and high total light transmission values.Type: GrantFiled: March 17, 1999Date of Patent: May 30, 2000Assignee: Bayer CorporationInventors: Michael A. Gerace, Sivaram Krishnan, James B. Johnson, Jeff M. Tennant
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Patent number: 6065836Abstract: A photochromic ophthalmic lens and a process for its preparation are disclosed. The lens comprise a substantially transparent substrate having a lenticular shape and, at least one film adhering to at least one surface of said substrate. The film contains a resinous blend of polycarbonate resin, and poycaprolactone and an effective amount of a photochromic dye selected from a group consisting of spiropyrans, spiroxazines, fulgides and fulgimides. In an additional embodiment the film contains a copoly(carbonate-lactone) block or random copolymer.Type: GrantFiled: July 30, 1998Date of Patent: May 23, 2000Assignee: Bayer CorporationInventors: Sivaram Krishnan, Robert A. Pyles, James B. Johnson, Timothy J. Pike
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Patent number: 6046301Abstract: A transparent thermoplastic molding composition having good release properties is disclosed. The composition which contains no magnetic elements contains a polycarbonate resin and 0.01 to 0.3 percent by weight of a mold release agent. The agent is the product of a reaction of a compound represented by formula (I) ##STR1## where R.sub.1 denotes a C.sub.1-30 -alkyl group, with at least one member selected from the group consisting of ##STR2## where R.sub.2 and R.sub.3 independently denote C.sub.1-30 - alkyl or an aryl group, and ##STR3## where n is 1-7.Type: GrantFiled: April 12, 1999Date of Patent: April 4, 2000Assignees: Bayer Corporation, Bayer AktiengesellschaftInventors: Daniel H. Bolton, Sivaram Krishnan, Jon M. Newcome, Jeffrey M. Tennant, David M. Derikart, Ramesh M. Pisipati, Wolfgang Ebert
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Patent number: 6008280Abstract: A thermoplastic molding composition having improved release properties is disclosed. The composition contains a polycarbonate resin and a mold release agent which is a hydroxy ester conforming structurally to ##STR1## where R is a member selected from the group consisting of glycerol, trimethylol propyl and pentaerythritol radicals, R' denotes a C.sub.6-20 hydrocarbon radical having at least one pendant hydroxyl group, and x is 2 to 4.Type: GrantFiled: November 20, 1997Date of Patent: December 28, 1999Assignee: Bayer CorporationInventors: Sivaram Krishnan, Jon M. Newcome, James B. Johnson, Ramesh M. Pisipati, Jeffrey M. Tennant
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Patent number: 5998520Abstract: A thermoplastic molding composition is disclosed comprising (A) at least one resinous component selected from the group consisting of (i) a homogeneous blend of polycarbonate resin and polycaprolactone and (ii) a copoly(carbonate-lactone) copolymer, and (B) at least one compound selected from a group consisting of benzopyrans, naphthopyrans, spirobenzopyrans, spironaphthopyrans, spirobenzoxazines, spironaphthoxazines, fulgides and fulgimides. The composition which contains the photochromic compound at an amount of 0.01 to 1.0 parts per hundred parts of weight of said (A) exhibits good photochromic properties.Type: GrantFiled: July 2, 1997Date of Patent: December 7, 1999Assignee: Bayer CorporationInventors: Sivaram Krishnan, Robert A. Pyles, James B. Johnson, Michael P. Jenkins, Timothy J. Pike
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Patent number: 5705546Abstract: A thermoplastic molding composition having improved release properties is disclosed. The composition contains a polycarbonate and an additive amount of an epoxy conforming structurally to ##STR1## where R is a member selected from the group consisting of glyceryl and trimethyl propyl radicals, x is 0 to 20 and R' is a C.sub.1-4 alkyl radical.Type: GrantFiled: June 13, 1996Date of Patent: January 6, 1998Assignee: Bayer CorporationInventors: Sivaram Krishnan, James B. Johnson
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Patent number: 5681905Abstract: An improved thermoplastic molding composition containing polycarbonate and a polyester copolymer based on cyclohexane-dimethanol, ethylene glycol and phthalic acid is disclosed. Improved resistance to gamma-radiation results from the incorporation of a siloxane compound which contains an oxirane group.Type: GrantFiled: August 16, 1996Date of Patent: October 28, 1997Assignee: Bayer CorporationInventors: James P. Mason, Sivaram Krishnan, Walter G. Chwala
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Patent number: 5596034Abstract: A thermoplastic molding composition having improved release properties is disclosed. The composition contains a polycarbonate resin and a mold release agent which is an ester conforming structurally to ##STR1## where R is a member selected from the group consisting of glyceryl, trimethylol propyl and pentaerythrityl radicals, m is 2 to 4, R' is a C.sub.8-20 hydrocarbon radical having a pendant alkyl group, and R" is the esterification residue of a C.sub.1-24 aliphatic or an aromatic carboxylic acid.Type: GrantFiled: September 7, 1995Date of Patent: January 21, 1997Assignee: Bayer CorporationInventors: Sivaram Krishnan, James B. Johnson, Robson Mafoti
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Patent number: 5508344Abstract: A thermoplastic molding composition comprising a resinous blend of polycarbonate, polyester and an impact modifier and an additive amount of a siloxane compound containing a pendant oxirane group is disclosed. It was surprisingly and unexpectedly discovered that unlike the corresponding compositions which contain no siloxane compound, the inventive composition is capable of being dried at low temperatures prior to molding and still maintain high impact strength.Type: GrantFiled: November 22, 1994Date of Patent: April 16, 1996Assignee: Bayer CorporationInventors: James P. Mason, William B. Villee, Sivaram Krishnan
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Patent number: 5484828Abstract: A thermoplastic polycarbonate molding composition free from organo phosphorus compounds and having an improved resistance to discoloration caused by exposure to High Intensity Discharge (HID) light and heat is disclosed. Accordingly, the molding composition contains (co)polycarbonate resin, a dimeric benzotriazole and an ester of a 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid. In a preferred embodiment, a sheet made of (co)polycarbonate resin is rendered improved resistance to discoloration by having applied to at least one of its surfaces an adherent protective film prepared from the polycarbonate composition of the invention.Type: GrantFiled: November 18, 1994Date of Patent: January 16, 1996Assignee: Bayer CorporationInventors: Kevin F. Dunay, Winfried G. Paul, Sivaram Krishnan
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Patent number: RE37200Abstract: A thermoplastic polycarbonate molding composition free from organo phosphorus compounds and having an improved resistance to discoloration caused by exposure to High Intensity Discharge (HID) light and heat is disclosed. Accordingly, the molding composition contains (co)polycarbonate resin, a dimeric benzotriazole and an ester of a 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid. In a preferred embodiment, a sheet made of (co)polycarbonate resin is rendered improved resistance to discoloration by having applied to at least one of its surfaces an adherent protective film prepared from the polycarbonate composition of the invention.Type: GrantFiled: August 23, 1999Date of Patent: May 29, 2001Assignee: Bayer CorporationInventors: Kevin F. Dunay, Winfried G. Paul, Sivaram Krishnan