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Hahn, Daejeon

Dohee Hahn, Daejeon KR

Patent application numberDescriptionPublished
20090141851NUCLEAR FUEL ROD FOR FAST REACTORS WITH OXIDE COATING LAYER ON INNER SURFACE OF CLADDING, AND MANUFACTURING METHOD THEREOF - Disclosed herein are a nuclear fuel rod for fast reactors, which includes an oxide coating layer formed on the inner surface of a cladding, and a manufacturing method thereof. The nuclear fuel rod for fast reactors, which includes the oxide coating layer formed on the inner surface of the cladding, can increase the maximum permissible burnup and maximum permissible temperature of the metallic fuel slug for fast reactors so as to prolong the its lifecycle in the fast reactors, thus increasing economic efficiency. Also, the fuel rod is manufactured in a simpler manner compared to the existing method, in which a metal liner is formed, and the disclosed method enables the cladding of the fuel rod to be manufactured in an easy and cost-effective way.06-04-2009
20110162764HIGH-CR FERRITIC/MARTENSITIC STEEL HAVING IMPROVED CREEP RESISTANCE AND PREPARATION METHOD THEREOF - High-Cr ferritic/martensitic steels having an improved tensile strength and creep resistance are provided, which includes 0.04˜0.13 weight % of carbon, 0.03˜0.07 weight % of silicon, 0.40˜0.50 weight % of manganese, 0.40˜0.50 weight % of nickel, 8.5˜9.5 weight % of chromium, 0.45˜0.55 weight % of molybdenum, 0.10˜0.25 weight % of vanadium, 0.02˜0.10 weight % of tantalum, 0.15˜0.25 weight % of niobium, 1.5˜3.0 weight % of tungsten, 0.05˜0.12 weight % of nitrogen, 0.004˜0.008 weight % of boron, and optionally, 0.002˜0.010 weight % of phosphorus or 0.01˜0.08 weight % of zirconium, and iron balance. By regulating the contents of alloying elements such as niobium, tantalum, tungsten, nitrogen, boron, zirconium, carbon, the high-Cr ferritic/martensitic steels with superior tensile strength and creep resistance are provided, and can be effectively used as an in-core structural material for Generation IV sodium-cooled fast reactor (SFR) which is used under high temperature and high irradiation conditions.07-07-2011

Patent applications by Dohee Hahn, Daejeon KR

Do-Hee Hahn, Daejeon KR

Patent application numberDescriptionPublished
20080234950WATER LEAKAGE-ACOUSTIC SENSING METHOD AND APPARATUS IN STEAM GENERATOR OF SODIUM-COOLED FAST REACTOR USING STANDARD DEVIATION BY OCTAVE BAND ANALYSIS - A water leakage-acoustic sensing method in a steam generator of a sodium-cooled fast reactor, the method including: calculating a standard deviation and an average of an octave band by octave band analysis of an input signal sound received from at least one predetermined acoustic sensor; comparing the calculated standard deviation and the calculated average of the octave band, and determining a size of the octave band based on a comparison result; calculating an average of standard deviations of the octave band recomposed by the determined size and normalizing the average of standard deviations; applying a predetermined weight, established by a predetermined neural network learning algorithm, to the normalized average of standard deviations; and generating leakage determination data based on the average of standard deviations to which the weight is applied.09-25-2008
20100135452LIQUID-METAL-COOLED FAST REACTOR CORE COMPRISING NUCLEAR FUEL ASSEMBLY WITH NUCLEAR FUEL RODS WITH VARYING FUEL CLADDING THICKNESS IN EACH OF THE REACTOR CORE REGIONS - A liquid-metal cooled fast reactor core having a nuclear fuel assembly constituted of nuclear fuel rods with varying cladding thicknesses in reactor core regions, in which: the nuclear fuel assembly (06-03-2010

Jongsok Hahn, Daejeon KR

Patent application numberDescriptionPublished
20100081776TRANSITION METAL CATALYTIC SYSTEMS AND METHODS FOR PREPARING ETHYLENE HOMOPOLYMERS OR COPOLYMERS OF ETHYLENE AND a-OLEFINS USING THE SAME - Provided are transition metal catalytic systems for preparing ethylene homopolymers or copolymers of ethylene with α-olefins. More specifically, provided are Group 4 transition metal catalysts, which is characterized in that the catalyst comprises around the Group 4 transition metal a cyclopentadiene derivative, and at least one aryloxide ligand(s) having a fluorenyl group or a derivative thereof (which is ready to be substituted at 9-position) that functions as an electron donor and serves to stabilize the catalytic system by surrounding an oxygen atom that links the ligand to the transition metal at ortho-position, and there is no cross-linkage between the ligands; catalytic systems comprising such transition metal catalyst and aluminoxane cocatalyst or boron compound cocatalyst; and processes for preparing ethylene homopolymers or copolymers of ethylene with α-olefins by using the same.04-01-2010
20100113720METHOD FOR PREPARING ELASTOMERIC COPOLYMERS OF ETHYLENE AND ALPHA-OLEFINS - Provided is a process for preparing copolymers of ethylene with α-olefin. More specifically, provided are transition metal compound being useful as catalyst for preparing those copolymers, a catalyst composition comprising the same, and a process for preparing elastic copolymers of ethylene with α-olefin, having the density of not more than 0.910, which can be adopted to a wide variety of applications including film, electric wires, and hot-melt adhesives. The catalyst composition is a catalytic system which comprises transition metal catalyst comprising a cyclopentadiene derivative and at least one anionic ligand(s) of aryloxy group with an aryl derivative at ortho-position, and boron or aluminum compound as an activator. Provided is a process for copolymerizing ethylene with α-olefin to produce copolymer having narrow molecular weight distribution and uniform density distribution with the density of not more than 0.910, with high activity and excellent reactivity on higher α-olefin.05-06-2010
20110065877ETHYLENE-PROPYLENE-DIENE COPOLYMER PRODUCTION METHOD - The present invention relates to a method for the production of an ethylene/propylene/diene copolymer by means of solution polymerisation, and more specifically one for a copolymer whose main components are ethylene, propylene and diene monomers using a catalyst of a transition metal coordination compound; the constituent components and characteristics of the copolymer being as follows. The catalyst composition provided by the present invention, which is used to produce a copolymer of which (a) the ethylene content is from 30 wt. % to 80 wt. %, (b) the propylene content is from 19.9% to 60 wt. % and (c) the diene content is from more than 0 wt. % to 15 wt. %, comprises a catalyst system using an activating agent of a compound of aluminium or boron, or aluminoxane together with a transition metal catalyst comprising at least one anionic ligand having an aryloxy group substituted with an aryl derivative in the ortho position and a cyclopentadiene derivative, and provides a highly active polymerisation method with outstanding reactivity with respect to ethylene, propylene and diene compounds.03-17-2011
20110098426TRANSITION METAL CATALYTIC SYSTEMS AND METHODS FOR PREPARING ETHYLENE HOMOPOLYMERS OR COPOLYMERS OF THE ETHYLENE AND a-OLEFINS USING THE SAME - Provided are transition metal catalytic systems for preparing ethylene homopolymers or copolymers of ethylene with α-olefins. More specifically, provided are Group 4 transition metal catalysts, which is characterized in that the catalyst comprises around the Group 4 transition metal a cyclopentadiene derivative, and at least one aryloxide ligand(s) having a fluorenyl group or a derivative thereof (which is ready to be substituted at 9-position) that functions as an electron donor and serves to stabilize the catalytic system by surrounding an oxygen atom that links the ligand to the transition metal at ortho-position, and there is no cross-linkage between the ligands; catalytic systems comprising such transition metal catalyst and aluminoxane cocatalyst or boron compound cocatalyst; and processes for preparing ethylene homopolymers or copolymers of ethylene with α-olefins by using the same.04-28-2011

Jong-Sok Hahn, Daejeon KR

Patent application numberDescriptionPublished
20080262174Homogeneous Catalyst System For Producing Ethylene Homopolymer or Ethylene Copolymers With Alpha-Olefins - Disclosed is a homogeneous catalyst system for producing an ethylene homopolymer or an ethylene copolymer with α-olefin. Specifically, this invention pertains to a transition metal catalyst which has stability under high temperature solution polymerization at 120˜250° C., in which a cyclopentadiene derivative and an electron donating substituent, both of which are bonded to a Group IV transition metal acting as a central metal, are crosslinked through a silyl derivative substituted with a cyclohexyl, to a catalyst system including such a transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst, and to a method of producing an ethylene homopolymer or an ethylene copolymer with α-olefin, having high molecular weight, using the catalyst system under conditions of high-temperature solution polymerization. The catalyst according to this invention has excellent thermal stability and compatibility with a paraffin hydrocarbon solvent and thus is effective in the production of an ethylene homopolymer or an ethylene copolymer with α-olefin having various properties in commercial polymerization processes.10-23-2008
20090176948Transition metal complexes, and catalysts compositions for preparing ethylene homopolymers or copolymers - Disclosed are a transition metal complex having a high catalytic activity for the preparation of an ethylene homopolymer or a copolymer of ethylene and α-olefin and a catalyst composition comprising the same. More specifically, there are provided a transition metal complex having, around a group IV transition metal, a cyclopentadiene derivative and at least one aryl oxide ligand with a heterocyclic aryl derivative substituted at the ortho-position thereof, with no crosslinkage between the ligands, a catalyst composition comprising the transition metal complex and an organoaluminum compound or boron compound as cocatalyst, and a method for the preparation of high molecular weight ethylene homopolymers or copolymers of ethylene and α-olefin using the same.07-09-2009
20090176949Transition metal complexes, catalyst compositions containing the same, and methods for preparing ethylene homopolymers or copolymers of ethylene and alpha-olefins using the same - The present invention relates to a transition metal complex and a transition metal catalyst composition comprising the same for the preparation of an ethylene homopolymer or a copolymer of ethylene and α-olefin. More particularly, it relates to a group IV transition metal catalyst having a cyclopentadiene derivative and at least one aryl oxide ligand in which an oxygen-containing heterocycle is fused at the ortho-position around a group IV transition metal, with no crosslinkage between the ligands, a catalyst composition comprising the transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst, and a process for preparing an ethylene homopolymer or a copolymer of ethylene and α-olefin using the same.07-09-2009
20090326175ARYLPHENOXY CATALYST SYSTEM FOR PRODUCING ETHYLENE HOMOPOLYMER OR COPOLYMERS OF ETHYLENE AND a-OLEFINS - The present invention relates to an arylphenoxy catalyst system producing an ethylene homopolymer or copolymers of ethylene and α-olefins, and a method of producing an ethylene homopolymer or copolymers of ethylene and α-olefins having a high molecular weight under a high temperature solution polymerization condition using the same. The catalyst system includes a group IV arylphenoxy-based transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst. In the transition metal catalyst, a cyclopentadiene derivative and arylphenoxide as fixed ligands are located around the group IV transition metal, arylphenoxide is substituted with at least one aryl derivative and is located at the ortho position thereof, and the ligands are not crosslinked to each other. The catalyst includes an environmentally-friendly raw material, synthesis of the catalyst is economical, and thermal stability of the catalyst is excellent. It is useful for producing an ethylene homopolymer or copolymers of ethylene and α-olefins having various physical properties in commercial polymerization processes.12-31-2009
20100048840TRANSITION METAL CATALYTIC SYSTEMS AND METHODS FOR PREPARING ETHYLENE HOMOPOLYMERS OR COPOLYMERS OF ETHYLENE AND OLEFINS USING THE SAME - Disclosed herein is a group IV transition metal catalyst for producing an ethylene homopolymer or an ethylene-olefin copolymers, having high catalytic activity, which includes a cyclopentadiene derivative and one or more anionic ligands having an aryl group substituted with an aryl derivative at an ortho-position thereof around a transition metal, the ligands not being crosslinked to each other, a catalyst system including the group IV transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst, and a method of producing ethylene homopolymers or ethylene-olefin copolymers using the catalyst system.02-25-2010
20100234545ETHYLENE COPOLYMER HAVING MULTIPLE PITCH MOLECULAR WEIGHT DISTRIBUTION AND THE METHOD OF PREPARING THE SAME - Disclosed are an ethylene polymerization process, a catalyst for use in the process, a production method employing the catalyst, and a product produced thereby. More specifically, disclosed is a process of producing an ethylene copolymer from ethylene and an alpha-olefin comonomer, in which the produced ethylene copolymer has a multimodal molecular weight distribution and excellent processability and physical properties, and thus can increase the value and productivity of products, including pipes and films. Particularly, the produced ethylene copolymer has a trimodal or higher molecular weight distribution or density distribution, and thus, when it is a linear low-density copolymer, it has an excellent effect of improving the impact strength of films, and when it is a medium-density ethylene copolymer, it can be produced into pipes, which have slow crack growth rate and can be used even at high temperature.09-16-2010
20100298512TRANSITION METAL COMPLEXES, CATALYSTS COMPOSITION CONTAINING THE SAME, AND PROCESS FOR PREPARING ETHYLENE HOMOPOLYMERS OR COPOLYMERS OF ETHYLENE AND ALPHA-OLEFINS USING THE SAME - The present invention relates to a transition metal complex useful as a transition metal catalyst in the preparation of an ethylene homopolymer or a copolymer of ethylene and an α-olefin, a catalyst composition comprising the same and a process of preparing an ethylene homopolymer or a copolymer of ethylene and an α-olefin using the same. More particularly, it relates to a transition metal complex having a cyclopentadiene derivative and at least one phenyl oxide ligand substituted at the 2-position of phenyl with, for example, a silyl group having a C11-25-2010
20110152475ETHYLENE ALPHA OLEFIN POLYMER FORMED BY USE OF METALLOCENE CATALYST - There is provided a method for producing copolymer that is composed of ethylene and alpha-olefin by a solution polymerization, and more specifically, a method for producing copolymer that is composed of ethylene and aromatic monomer as main components by using a transition metal catalyst including a cyclopentadiene derivative, and one or more anionic ligand having aryloxy group in which an aryl derivative is substituted at an ortho-position06-23-2011

Patent applications by Jong-Sok Hahn, Daejeon KR

Minsoo Hahn, Daejeon KR

Patent application numberDescriptionPublished
20110112842METHOD AND APPARATUS FOR EDITING AUDIO OBJECT IN SPATIAL INFORMATION-BASED MULTI-OBJECT AUDIO CODING APPARATUS - Disclosed is an audio object editing apparatus of a multi-object audio coding apparatus. The audio object editing apparatus of the multi-object audio coding apparatus may include an object information extracting unit to receive an object bit stream and to extract object information from the object bit stream, a downmix processing unit to receive a downmix signal, and to control the downmix signal using object editing information and the object information, and a bit stream processing unit to edit the object information according to the object editing information, and to generate a controlled object bit stream based on the edited object information.05-12-2011
20110166867MULTI-OBJECT AUDIO ENCODING AND DECODING APPARATUS SUPPORTING POST DOWN-MIX SIGNAL - A multi-object audio encoding and decoding apparatus supporting a post downmix signal may be provided. The multi-object audio encoding apparatus may include: an object information extraction and downmix generation unit to generate object information and a downmix signal from input object signals; a parameter determination unit to determine a downmix information parameter using the extracted downmix signal and the post downmix signal; and a bitstream generation unit to combine the object information and the downmix information parameter, and to generate an object bitstream.07-07-2011

Sun Hwa Hahn, Daejeon KR

Patent application numberDescriptionPublished
20090037380System and method for providing integrated search using URI database - Provided is a system for providing integrated search using a URI database, the system including a URI database that stores associated information corresponding to a specific entity as object identifiers; an entity information processing unit that searches a URI database in accordance with a query input of a user so as to check the type of an entity and provides entity information; and an integrated-search result providing unit that provides an integrated-search result page for the corresponding entity, based on the entity information provided from the entity information processing unit.02-05-2009
20100205229SYSTEM AND METHOD FOR INSTANCES REGISTERING BASED ON HISTORY - A system for registering instances based on history is disclosed. An instance registration setting unit reads ontologies and storing them in memory, and provides an interface capable of editing one or more instances included in each of classes. The instances are provided through an ontology viewer for visualizing relationships between the stored ontologies. An instance registration editing unit edits, searches for, and registers the instances using the interface provided by the instance registration setting unit, and supports the editing by extracting one or more object names based on external information while managing the edited instances based on the history.08-12-2010

Young-Sik Hahn, Daejeon KR

Patent application numberDescriptionPublished
20090156395Method for Preparing Metal Oxide Containing Precious Metals - The present invention relates to a method for preparing a metal oxide containing precious metals, which can be used for a catalyst for purifying automobile exhaust gases and has excellent heat resistance and, more particularly, to a method for preparing a metal oxide containing precious metals including the step of continuously reacting a reaction mixture, including (i) water, (ii) a water-soluble precious metal compound, (iii) a water-soluble cerium compound and (iv) at least one water-soluble metal compound selected from the group consisting of a zirconium compound, a scandium compound, a yttrium compound and a lanthanide metal compound other than a cerium compound, at a temperature from 2000 C to 700° C. and at a pressure from 180 bar to 550 bar, wherein the molar ratio of precious metal to metal other than the precious metal in a reaction product is in the range from 0.001 to 0.1.06-18-2009
20100227222Lithium-Metal Composite Oxides and Electrochemical Device Using the Same - Disclosed is a lithium-containing metal composite oxide comprising paramagnetic and diamagnetic metals, which satisfies any one of the following conditions: (a) the ratio of intensity between a main peak of 0±10 ppm (Io PPm) and a main peak of 240±140 ppm (I240 pPm), Uoppm/124o PPm), is less than 0.117·Z wherein Z is the ratio of moles of the diamagnetic metal to moles of lithium; (b) the ratio of line width between the main peak of 0±10 ppm (Io PPm) and the main peak of 240+140 ppm (I24o PPm), (W24o PPm/WO ppm), is less than 21.45; and (c) both the conditions (a) and (b), the peaks being obtained according to the 7Li—NMR measurement conditions and means disclosed herein. Also, an electrode comprising the lithium-containing metal composite oxide, and an electrochemical device comprising the electrode are disclosed. The lithium-containing multicomponent metal composite oxide shows crystal stability and excellent physical properties as a result of an improved ordering structure of metals, in which the components of the composite oxide are uniformly distributed. Thus, it can provide a battery having high capacity characteristics, long cycle life characteristics and improved rate characteristics.09-09-2010

Young-Sik Hahn, Daejeon JP

Patent application numberDescriptionPublished
20100227221Preparation Method of Lithium-Metal Composite Oxides - Disclosed is a method for preparing a lithium-metal composite oxide, the method comprising the steps of: (a) mixing an aqueous solution of one or more transition metal-containing precursor compounds with an alkalifying agent and a lithium precursor compound to precipitate hydroxides of the transition metals; (b) mixing the mixture of step (a) with water under supercritical or subcritical conditions to synthesize a lithium-metal composite oxide, and drying the lithium-metal composite oxide; and (c) subjecting the dried lithium-metal composite oxide either to calcination or to granulation and then calcination. Also disclosed are an electrode comprising the lithium-metal composite oxide, and an electrochemical device comprising the electrode. In the disclosed invention, a lithium-metal composite oxide synthesized based on the prior supercritical hydrothermal synthesis method is subjected either to calcination or to granulation and then calcination. Thus, unlike the prior dry calcination method or wet precipitation method, a uniform solid solution can be formed and the ordering of metals in the composite oxide can be improved. Accordingly, the lithium-metal composite oxide can show crystal stability and excellent electrochemical properties.09-09-2010