• Title/Summary/Keyword: p-xylene

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유기용매내성세균에 의한 INDIGO 와 INDIRUBIN의 생산

  • Jang, Jin-Seong;Gang, Jeong-Hwan;Lee, Hui-Jeong;Choe, Yeong-Hwan;Lee, Yeong-Geun;Jeong, Yeong-Gi;Ju, U-Hong
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.590-592
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    • 2000
  • The indole tolerance level of Pseudomonas savastanoi BCNU 106 was as high as 300 mg/ml when toluene or p-xylene was added to the medium to 20% by volume. Pseudomonas savastanoi BCNU 106 grown in a two-phase system containing the various concentrations of indole and solvents produced indigo and indirubin. The optimal condition in the production of indigo and indirubin was also studied.

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Viscosities of Supercooled Water and Other Liquids

  • Bahng, Jun-Su;Hahn, Sang-Joon;Jhon, Mu-Shik
    • Journal of the Korean Chemical Society
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    • v.15 no.4
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    • pp.171-175
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    • 1971
  • Significant structure theory has been applied to the viscosities of supercooled liquids with success. In the supercooled region, the effect of free volume decrease is so significant that the thermal effects on the solid-like volume must be considered properly. In addition, the two state theories proposed by Jhon and Eyring for water and Litovitz et al. for boron trioxide have been successfully applied to the structure change in the liquid state. Considered liquids are benzene, carbon tetrachloride, p-xylene, water and boron trioxide.

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Characterization of Pseudomonas putida 1K1 Capable of Growing on Extremely High Concentration of Toluene (고농도 Toluene에서 생육 가능한 Pseudomonas putida 1K1의 특성)

  • Cho, Kyung-Yun;Chun, Hyo-Kon;Han, Dong-Cho;Kho, Yung-Hee
    • Microbiology and Biotechnology Letters
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    • v.17 no.3
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    • pp.236-240
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    • 1989
  • The isolated bacterial strain 1K1 able to grow on extremely high concentration of toluene was morphologically and physiologically best described as Pseudomonas putida. This strain could grow on at least eight aromatic compounds, e.g., benzene, benzoate, phenol, o-cresol, m-cresol, toluene, m-tolunte, and xylene, but did not Brow on alkanes, such as hexane, octane, decane, and cyclohexane. Strain 1K1 could grow on above 95% toluene, but it could not grow on above 1% of other aromatic compounds. In the point of survival, strain 1K1 was resistant to high concentration of alkanes, appreciably resistant to toluene and xylene, and damaged by to other aromatic compounds. Strain 1K1 which grew on high concentration of toluene had irregular cell shape in comparing with normal cell shape of the genus Pseudomonas. Strain 1K1 was shown to have at least two aromatic compound dissimilation pathway, one for benzoate and the other for toluene.

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Comparison of the Quality Characteristics and Aroma of M. Longissimus from Korean Native Black Pigs and Modem Genotype Pigs during Vacuum Packaged-Chilling (재래종 및 개량종 돼지 등심의 진공포장 냉장중 품질특성 및 향기비교)

  • Kang, Sun-Moon;Lee, Sung-Ki
    • Food Science and Preservation
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    • v.14 no.3
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    • pp.247-255
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    • 2007
  • This study compared the quality characteristics, including aroma, of M. longissimus from five Korean native black barrows(64 kg, KNP) and five modem genotype barrows($Landrace{\times}Yorkshire{\times}Duroc$, 114 kg, MGP), during vacuum packaged-chilling. The samples were vacuum packaged, stored at $2{\pm}0.3^{\circ}C$ for 12 days, and then subjected to quality measurement. The KNP had higher fat content than did MGP(p<0.05), but KNP contained lower C14:0, C18:3 and C20:5 concentrations than did MGP(p<0.05). The KNP showed lower pH values(p<0.05) and water-holding capacities than did MGP, and were redder in color than MGP during storage. The TBARS increased more quickly in KNP than in MGP samples during storage. In texture, KNP showed firmer muscle tone than did MGP during storage(p<0.05). Various aroma compounds including 3-methyl-l-butanol, 2-ethyl hexanol and m-xylene were detected with SPME-GC/MS after 12 days of storage, and aroma patterns of KNP and MGP, obtained with an electronic nose, differed during storage.

Iron Catalyzed Atom Transfer Radical Polymerization of Methyl Methacrylate Using Diphenyl-2-pyridylphosphine as a Ligand

  • Xue, Zhigang;Noh, Seok-Kyun;Lyoo, Won-Seok
    • Macromolecular Research
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    • v.15 no.4
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    • pp.302-307
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    • 2007
  • The living radical polymerization of methyl methacrylate (MMA) by atom transfer radical polymerization, (ATRP) employing a $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine (PyP) catalytic system (X=Cl, Br), was investigated using several initiators and solvents at various temperatures. Most of the polymerizations with the PyP ligand were well controlled, with a linear increase in the number average molecular weights ($M_n$) vs. conversion, with relatively low molecular weight distributions ($M_w/M_n=1.2-1.4$) throughout the reactions. The measured weights matched those of the predicted values. The ethyl-2-bromoisobutyrate (EBriB) initiated ATRP of MMA, with the $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine catalytic system (X=Cl, Br), was better controlled in p-xylene at $80^{\circ}C$ than the other solvents used in this study.

Polymerization of Tetrahydrofuran with New Transition Metal Catalyst and Its Mechanism: (p- Methylbenzyl)- o -cyanopyridinium Hexafluoroantimonate

  • 강준원;한양규
    • Bulletin of the Korean Chemical Society
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    • v.18 no.4
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    • pp.433-438
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    • 1997
  • (p-Methylbenzyl)-o-cyanopyridinium hexafluoroantimonate, a new catalyst, was synthesized by the reaction of o-cyanopyridine with α-bromo-p-xylene followed by exchange of counteranion with SbF6θ. We examined the effect of the catalyst on the bulk polymerization of tetrahydrofuran under various conditions. The catalytic activity was best in the presence of 1 : 1 of epichlorohydrin used as cocatalyst versus catalyst concentration. The resulting polymers had relatively low conversions in 1.0-40%. Their number average molecular weights were in the range of 800 to 5300. Propagation rate increased with increase in temperature according to an Arrhenius expression giving an activation energy of 62 KJ/mol. We also found catalyst proceeds via a cationic mechanism.

Isolation and Characterization of Denitrifying Phenol-Degrading Bacterium Pseudomonas sp. HL100. (탈질화성 페놀 분해균 Pseudomonas sp. HL100의 분리 및 특성)

  • 박수동;김연희;이흥식
    • Microbiology and Biotechnology Letters
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    • v.26 no.4
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    • pp.303-308
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    • 1998
  • A bacterial strain which utilizes phenol under denitrifying condition was isolated from the industrial waste water collected from the Chong-ju Industrial Complex. The strain was identified as Pseudomonas species from the morphological, physiological, and biochemical characteristics and designated as HL100. The strain can utilize phenol as the sole source of carbon and energy when nitrate is provided as the terminal electron acceptor. The isolated strain completely degraded 3 mM of phenol within 110 hour with concomitant reduction of nitrate to nitrite. The observed maximum doubling time was 20 hours. Under appropriate condition, complete reduction of nitrate to atmospheric N$_2$ was observed indicating that the isolated strain could perform complete steps of denitrification. The strain showed optimal growth at pH 7.0 and temperature of 37$^{\circ}C$ under denitrifying phenol-degrading condition. The strain can also utilize toluene as the sole carbon and energy source under the same growth condition. However, no growth was detected on xylene and benzene.

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