• 제목/요약/키워드: Crosslinked

검색결과 583건 처리시간 0.033초

A study on the whole cell immobilized glucose oxidase from Aspergillus niger

  • Choe, I.S.;Roh, J.K.;Han, M.H.
    • 한국미생물생명공학회:학술대회논문집
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    • 한국미생물생명공학회 1979년도 추계학술대회 심포지움
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    • pp.245.2-246
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    • 1979
  • Heat treated whole cell of Aspergillus niger containing glucose oxidase-catalase system was entrapped in gelatin matrix crosslinked by glutaral-dehyde. The reaction characteristics of immobilized enzyme was studied in a fludized reactor. Heat treatment enhanced the stability and improved the properties of micellium for the immobilized process. The immobilized enzyme system showed the maximum activity at $35^{\circ}C$ and at pH 5.5. The optimum substrate concentration was 0.04M glucose. The activity of immobilized glucose oxidase was in proportion to the concentration of dissolved oxygen in reaction mixture as other reaction conditions were fixed. It was also demonstrated that the limiting factor for the activity of the immobilized glucose oxidase was the oxygen diffusion resistance which increases proportionally to the glucose concentration.

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Photocrosslinking of Low Molar Mass Poly(ethylene glycol)s

  • Hong, Ki-Chul;Kim, Jinhwan;Bae, Jin-Young
    • Macromolecular Research
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    • 제9권5호
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    • pp.253-258
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    • 2001
  • Crosslinked poly(ethylene glycol)s (PEGs) were prepared by ultraviolet irradiation of low molar mass, liquid PEGs in the presence of benzophenone (BP) as a photoinitiator. The networks obtained have been characterized by DSC, IR, and contact angle measurements, and their water absorption and equilibrium swelling have been examined. The percent of gel formed and degree of swelling of the networks in water were dependent on the amount of BP in the reaction mixture, irradiation time and molar mass of PEG. Gel fraction yield exceeded 84%, and equilibrium swelling in water varied from 49 to 244%.

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난연성 동심중성선 전력 케이블의 재료에 대한 평가 기술 (Assessment of material analysis for Halogen free flame retardant concentric neutral type Power cable)

  • 소진중;심대섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 C
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    • pp.1460-1462
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    • 2002
  • The test methods on materials of electrical power cable are used in accordance with 25 specifications of IEC, ASTM, ICEA, KS and KEPCO Spec. The validation of test methods were checked and stablished by solving the problems occurred during the test. These tests are flammability, degree of acidity of gases, amount of halogen acid gas, smoke density, oxygen index, amount of ion in semiconductor, void, amber, contaminant and water tree, crosslinked density. Then the performance of power cable made by A, B, C and D company were evaluated and compared.

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트리억제제 첨가에 의한 저밀도 폴리에틸렌의 내방사선성 향상 (I) (The Improvement of Radiation Characteristics of Low Density Polyethylene by Adding Treeing Inhibitors (I))

  • 김기엽;이청;류부형;임기조
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.926-928
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    • 1999
  • Treeing inhibitors of barbituric acid derivatives effects on the electrical properties of crosslinked low density polyethylene under radiation environments were investigated. The electrical parameters for tree inception voltage, AC breakdown strength, volume resistivity, capacitance and dissipation factor at 1MHz and thermoluminescence, gel content measurements were discussed as a function of irradiated dosages. From the results, barbituric acid among the treeing inhibitors was shown the best treeing and radiation resistance.

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Sulfa제의 Dual Action에 의한 지속성과 항균성 (Antibiotics and Durability by Action of Sulfa Agents)

  • 공승대;황성규;윤철훈;김진영;이한섭
    • 한국응용과학기술학회지
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    • 제17권4호
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    • pp.267-272
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    • 2000
  • Dual-actions are the most recently used delivery system in drug study. Dual-action agents are unique chemical entities comprised of two different type of antibacterial compounds covalently linked together in a single molecule in such a way that both components are able to exert their bactericidal properties. Crosslinked sulfadiazine-sulfanilamide such as antibiotics is synthesized by synthetic handle with glutaraldehyde. As a result, New synthetic antibacterial agent exhibited the broad antibacterial activities against gram(+) and gram(-) of 4 strains and a long durability supposing that the stomach and blood.

고온 연료전지용 새로운 형태의 고분자 전해질막의 합성과 특성연구 (Synthesis and Properties of New Type of Proton Conducting Polymer Membrane for High Temperature Fuel Cells)

  • 이중희;삼부 바드라;김남훈;이홍기;김홍건
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 추계학술대회 논문집
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    • pp.166-169
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    • 2009
  • Poly(benzimidazole-co-aniline) (PBIANI), a self-crosslinked, net-structured, proton conducting polymer has been synthesized for the membrane of high temperature proton exchange membrane fuel cells (HT-PEMFC) with improved proton conductivity and mechanical strength. The stress at break (26$\pm$3MPa)and proton conductivity (167 mS cm-1)of the phosphoric acid doped PBIANI (DPBIANI)membrane is much higher than those of other doped polybenzimidazole(PBI) type membranes.

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전기투석공정을 위한 Poly(ethylene)과 poly(tetrafluoroethylene)다공성 필름을 이용한 가교된 poly(vinylbenzyl trimethyl ammonium chloride)복합막 제조 (Crosslinked poly(vinylbenzyl trimethy ammonium chloride)-impregnated poly(ethylene) and poly(tetrafluoroethylene) composite membranes using for electrolysis process)

  • 이정수;장봉준;김정훈;이수복;강호
    • 한국막학회:학술대회논문집
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    • 한국막학회 2008년도 춘계 총회 및 학술발표회
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    • pp.180-184
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    • 2008
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Effect of Coloration on the Hydrophilicity and Swelling Properties of Poly-HEMA Hydrogels

  • Jang, Jin-Ho;Park, Hwa-Sung;Jeong, Yong-Kyun
    • 한국염색가공학회지
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    • 제19권2호
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    • pp.7-13
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    • 2007
  • Photopolymerization of 2-hydroxyethyl methacrylate(HEMA), in the presence of ethyleneglycol dimethacrylate(EGDMA) and 1-Hydroxycyclohexyl phenyl ketone as crosslinker and photoinitiator, respectively, produced crosslinked poly-HEMA hydrogels. The hydrogels were colored by the exhaustion of vinylsul-phone-type reactive dyes. Good colorfastness to laundering was achieved when colored with C.I. Reactive Black 5. We investigated that the effect of coloration on the hydrophilicity and swelling properties of the films. More hydrophilic gel-surfaces were generated with in increase in coloration and crosslinking. Higher surface energy was observed with higher crosslinking level. The more rapid and higher water swellability of poly-HEMA gels after coloration may be resulted from a more opened gel structure by the easier hydration of the hydrophilic sulphonic acid groups of the reacted dyes in water.

Tracer diffusion in a polymer network: influence of network flexibility

  • Kim, Haein;Kim, Jun Soo
    • EDISON SW 활용 경진대회 논문집
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    • 제6회(2017년)
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    • pp.39-45
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    • 2017
  • We present a Brownian dynamics simulation study on the diffusion of a neutral tracer particle confined in a regularly crosslinked polymer network, especially, when the tracer size is comparable to the mesh size of the network. Polymer networks with different mesh sizes are prepared and compressed to the extent that the total polymer densities become the same. Irrespective of the network mesh size, the tracer diffusion in the networks is slowed down, showing the subdiffusion on intermediate time scales followed by the normal diffusion at long times. However, the confinement effect on the tracer diffusion becomes more significant when network strands are tightly stretched with smaller mesh size. The time scales of dynamic transitions are analyzed in terms of the probability distribution of time-correlated particle displacements.

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