• 제목/요약/키워드: Reaction media

검색결과 605건 처리시간 0.029초

A Facile One-Pot Operations of Reduction and Allylation of Nitrobenzaldehydes Mediated by Indium and Their Applications

  • Cho, Yong-Seo;Kang, Kyung-Ho;Cha, Joo-Hwan;Choi, Kyung-Il;Pae, Ae-Nim;Koh, Hun-Yeong;Chang, Moon-Ho
    • Bulletin of the Korean Chemical Society
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    • 제23권9호
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    • pp.1285-1290
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    • 2002
  • Various nitrobenzaldehydes were simultaneously allylated and reduced using indium in the presence of HCl in aqueous media to give compounds having both functionality of homoallylic alcohol and aromatic amine. Sequential protection of the amino gro up and oxidation of the anilinyl homoallylic alcohol provided useful precursors of heterocyclic compounds such as dihydroindolones and dihydroquinolones, which could be efficiently synthesized through intramolecular cyclization reaction.

각종 적혈구에 대한 장염비브리오의 용혈성에 관한 연구 (Studies on Hemolysis of Vibrio Parahaemolyticus to Various Erythrocytes)

  • 주진우;김영희
    • 대한미생물학회지
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    • 제19권1호
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    • pp.49-54
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    • 1984
  • The authors isolated Vibrio parahaemolyticus from sea water, sea mud and various marine products in Busan shore area from 1981 to 1982, Among 100 isolated strains, 66 strains showed positive reaction in Kanagawa phenomenon. With the above 66 strains, the authors carred out test for detecting hemolysis activity of V.parahaemolyticus on human, rabbit, chicken, pig, goat, sheep and cow erythrocytes, in different media, such as modified Wagatsuma, nutrient, peptone and brain heart infusion agar plates media. The following results were obtained: 1. The media which can be used for Kanagawa phenomenon of V. parahoemolyticus were modified Wagatsuma, nutrient, peptone agar media, but not brain heart infusion agar medium. 2. The erythrocytes which showed positive Kanagawa phenomenon were those of human, rabbit, chicken and pig, but sheep, goat and cow erythrocytes showed no sensitivities.

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바이오필터 담체 모델링 및 운전자료 비교에 대한 연구 (Biofiltration Modeling for Packing Media Compared To a Small-scale Operation)

  • 허남수;조대철;권성현
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2004년도 추계학술대회
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    • pp.272-273
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    • 2004
  • Filter media are one of themost important choices when bilfiltration is applied. Filter media provide adsorbing microbes with available sites for residence and the residential cells grow to degrade or decompose target waste gases. Up to date, filter media were only qualitatively analyzed. As a quantitative approach to filter material for biofiltration, a simple model based on reaction kinetics and mass action law (Ottengraf's Model in 1983) was presented. Cork, zeolite, and granulated activated carbon were tested in terms of effective surface area, cell covered fraction of adsorbing sites, surface roughness, and pore size distribution. The cell covered fraction, surface roughness and hydrophilicity was found to be closely related to the efficiency of gas degradation in biofiltration. The cork was the best candidate for cell residence and growth in this work.

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Montmorillonite K-10 Clay as an Efficient Reusable Heterogeneous Catalyst for the Solvent-Free Microwave Mediated Synthesis of 5-Substituted 1H-Tetrazoles

  • Marvi, Omid;Alizadeh, Abdolhamid;Zarrabi, Saeid
    • Bulletin of the Korean Chemical Society
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    • 제32권11호
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    • pp.4001-4004
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    • 2011
  • Various 5-substituted 1H-tetrazole derivatives were synthesized in a simple and environmentally benign method from the reaction of aryl and benzyl nitriles with sodium azide in solvent-free media using montmorillonite K-10 clay as solid recyclable heterogeneous acidic catalyst and microwave irradiation in good yields and short reaction times.

Condensed Tannin을 포함한 접착제에서 Tannin과 Formaldehyde의 반응에 관한 연구 (Reaction Study of Tannin with Formaldehyde in the Adhesive Containing Condensed Tannin)

  • 정경호
    • 한국염색가공학회지
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    • 제4권3호
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    • pp.116-121
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    • 1992
  • This paper is on for a material to replace the petroleum-based resins used as adhesives for the fiber in rubber composite materials. The study limited to the reaction properties of tannin with formaldehyde. Tannin-formaldehyde(TF) reactions were carried out in aqueous media. Rates of reaction were strongly dependent on concentration, temperature, pH, and the mole ratio of tannin to formaldehyde. Viscosities of reaction mixtures were followed up to gelation. The reactivity of tannin-formaldehyde resins was greater than that of resorcinol-formaldehyde resins. To formulate an adhesive, a styrene-butadiene-vinyl pyridine terpolymer latex(L) was added to the TF. This preliminary results suggest that the condensed tannins have considerable promise as substitutes for resorcinol used in resin formulation for bonding of fiber to rubber.

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효율적 수소 생산을 위한 메탄 수증기 개질 반응기에서의 불연속적 가스 유입의 영향 (Effect of discontinuous mixture gas feeding on effective hydrogen production in a steam reformer frommethane)

  • 이신구;박준근;임성광;배중면
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 추계학술대회 논문집
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    • pp.25-28
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    • 2008
  • Steam reforming reaction is a matured technology to get hydrogen from hydrocarbon fuels compared with other reforming reactions such as partial oxidation(POX), autothermal reforming(ATR). It is so endothermic that it needs heat source to activate the reaction. Due to the reaction characteristics, heat transfer limitation phenomena generally occur in the steam reformer. As one of new ideas, the effect of discontinuous gas feeding is investigated based on heat transfer characteristics. The new operating method is usually favorable at high GHSV region(i.e. over $10,000h^{-1}$). In order to numerically simulate the physical issues, numerical approach is adopted based on heterogeneous reaction model, two-equation model in energy equation, and other constitutive models in porous media.

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Reactivity of Superoxide Ion with Halogenonitriles and Dihalocarbons in Aprotic Media

  • 전승원;최용국
    • Bulletin of the Korean Chemical Society
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    • 제16권11호
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    • pp.1060-1064
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    • 1995
  • The reactivity of superoxide ion (O2-.) with halogenated substrates is investigated by cyclic voltammetry and rotated ring-disk electrode method in aprotic solvents. The more positive the reduction potential of the substituted nitrile, the more facile is nucleophilic displacement by O2-.. The reaction rates of halogenonitriles with O2-. vary according to the leaving-group propensity of halide (Br > Cl > F). The relative reaction rates of other substituted nitriles are in the order of electron-withdrawing propensity of the substituent group (CN > C(O)NH2 > Ph ≒ CH2CN). The reaction of O2-. with dihalocarbons indicates that five-membered rings can be rapidly formed by the cyclization of substrate and O2-., and the relative rates of cyclization depend on the number of methylenic carbons {Br(CH2)nBr, [n=1 < 2 < 3 > 4 > 5]}. Mechanisms are proposed for the reaction of O2-. with halogenated substrates.

The Role of Sense of Belonging in Social Media Usage: A Tale of Two Types of Users

  • Liu, Chung-Tzer;Guo, Yi Maggie
    • Asia pacific journal of information systems
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    • 제25권2호
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    • pp.403-422
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    • 2015
  • Social media websites have continued to proliferate, and the way in which people stay connected has also evolved. The issue of user loyalty a website remains crucial given that the competition is severe. Websites need loyal users who continue to use their sites to survive and be successful. In this research, we applied self-regulation framework to investigate the factors leading to user loyalty to a social media site. In particular, the role of sense of belonging, which is a common emotional reaction to a social media site, is examined. A survey of users in a popular social media site in Taiwan was conducted. Results show that both sense of belonging and service quality have direct effect on loyalty, whereas trust affects loyalty indirectly by fostering a sense of belonging. Service quality affects loyalty through trust and sense of belonging. Notably, trust has insignificant effect on loyalty as originally proposed. Users are then classified into two groups, namely, heavy and light users, based on their usage. Among light users, service quality has no direct effect on loyalty. Therefore, sense of belonging has sole direct impact on loyalty. Both service quality and sense of belonging contribute to loyalty in users who spend more time online. Implications of this study are also discussed.

Optimal Media Conditions for the Detection of Extracellular Cellulase Activity in Ganoderma neo-japonicum

  • Jo, Woo-Sik;Park, Ha-Na;Cho, Doo-Hyun;Yoo, Young-Bok;Park, Seung-Chun
    • Mycobiology
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    • 제39권2호
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    • pp.129-132
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    • 2011
  • To determine the optimal media conditions for the detection of the extracellular cellulase activity in Ganoderma neo-japonicum, we varied three media conditions: dye reagent, pH, and temperature. We evaluated the use of four dyes, Congo red, phenol red, remazol brilliant blue, and trypan blue. To observe the effect of pH on the chromogenic reaction, we tested media ranging from 4.5 to 8.0. To research the effect of temperature on the clear zone and the fungus growing zone, we tested temperatures ranging from 15 to $35^{\circ}C$. On the whole, the best protocol called for Ganoderma neo-japonicum transfer onto media containing Congo red with a pH of 7.0, followed by incubation at $25^{\circ}C$ for 5 days. Our results will be useful to researchers who study extracellular enzyme activity in Ganoderma neo-japonicum.

식물병원성세균의 약제저항성에 관한 연구 III. 벼 흰빛잎마름병균에 있어서 Streptomycin 내성균주의 몇 가지 변이 (Studies on the Chemical Resistance of Phytopathogenic Bacteria III. Some Variations on the Streptomycin Resistant Isolates of the Rice Bacterial Leaf Blight Pathogen, Xanthomonas oryzae(Uyeda et Ishiyama) Dowson)

  • 조원철;심재욱
    • 한국응용곤충학회지
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    • 제16권4호
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    • pp.235-239
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    • 1977
  • 선발에 의하여 얻은 벼 흰빛잎마름병균 Xanthomonas oryzae의 Streptomycin 내성균에 대하여 병원성, 배지내에서의 생장량 및 자외선 감수성에 대한 변이성을 조사하여 다음과 같은 결과를 얻었다. (1) SM 내성균은 Wase-Aikoku-3, Rant Emas-2 황옥 및 Kimmase의 4개 판별품종에 대한 병원성 비교에서 75-6의 내성균주가 황옥에 대하여 감수성 반응이 모균과 달리 중정도의 저항성을 나타내었다. 2) SM-내성균은 정상배지에서 모균보다 약간 높은 생장량을 보였고 100ug/ml Agrepto 첨가 배지에서는 접종후 60시간까지 생장이 조지되었으나 70시간 이후에는 모균의 생장량을 능가하였다. (3) SM-내성균은 254mu 파장의 자외선 조사에서 모균과 동일한 감수성을 나타내어 내성인자는 안정된 것으로 생각되었다.

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