• 제목/요약/키워드: Anhydrous

검색결과 313건 처리시간 0.023초

Oxidation of Dibenzothiophene Catalyzed by Surfactant-Hemoprotein Complexes in Anhydrous Nonpolar Organic Solvents

  • Ryu, Keun-Garp;Chae, Young-Rae;Kwon, O-Yul
    • Journal of Microbiology and Biotechnology
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    • 제13권5호
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    • pp.647-650
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    • 2003
  • In anhydrous organic solvents, the complexes formed between AOT (dodecylbenzene sulfuric acid sodium salt) and hemoproteins, such as hemoglobin, myoglobin, or cytochrome c, displayed remarkably higher activity than the hemoprotein powders to oxidize dibenzothiophene, a model compound of organic sulfurs contained in fossil fuels. In slightly hydrophobic organic solvents, such as ethyl acetate and butyl acetate, dibenzothiophene was completely oxidized catalytically by the cytochrome c-AOT complex with cumene hydroperoxide (${\alpha},{\alpha}-dimethylbenzyl$ hydroperoxide) as an oxidant. In highly hydrophobic organic solvents, such as decane and hexadecane, however, the activity of the cytochrome c-AOT complex decreased, presumably due to the aggregation of the hemoprotein-AOT complex in these solvents.

Electrorheology of the Suspension Based on Chitosan Adipate as a New Anhydrous ER Fluid

  • Choi, Ung-Su;Ko, Young-Gun
    • KSTLE International Journal
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    • 제2권2호
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    • pp.142-145
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    • 2001
  • The electrorheology of the chitosan adipnate suspension in silicone oil was investigated. Chitosan adipnate suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the chitosan adipnate suspension exhibited a linear dependence on the volume fraction of particles and an electric field power of 1.88. The experimental results for the chitosan adipnate suspension correlated with the conduction models and this suspension was found to be an anhydrous ER fluid.

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Studies on the Properties of Thexylboronic Acid and Its Derivatives

  • Cha, Jin-Soon;Brown, Herbert C.
    • Bulletin of the Korean Chemical Society
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    • 제26권2호
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    • pp.292-296
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    • 2005
  • Physical and chemical properties of thexylboronic acid and its derivatives such as thexylboroxine and ethylene glycol or diethanolamine thexylboronic ester have been studied. Thexylboronic acid can be extracted from an organic solution with an aqueous sodium hydroxide solution as an “te”complex. It is readily converted into thexylboroxine in the presence of anhydrous magnesium sulfate in pentane. It reacts with simple alcohols only slowly; however, it reacts readily with excess diethanolamine in the presence of anhydrous magnesium sulfate to give the corresponding ester.

Electrorheology of HMDA Coupled Chitosan Succinate Suspension as an Anhydrous ER Fluid

  • Kong, Seong-Wook;Kim, Seung-Wook;Lee, Sang-Soon;Choi, Ung-Su
    • KSTLE International Journal
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    • 제9권1_2호
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    • pp.7-9
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    • 2008
  • The electrorheology of the HMDA coupled chitosan succinate suspension in silicone oil was investigated. HMDA coupled chitosan succinate suspension showed a typical ER response upon application of an electric field. The shear stress for the HMDA coupled chitosan succinate suspension exhibited an electric field power of 2.0. The experimental results for the HMDA coupled chitosan succinate suspension was found to be an anhydrous ER fluid.

Study on the Reaction of Isoxazolidine-3-thione with Anhydrous Aluminum CHloride; Synthesis and Mechanism of the Formation of N-(p-Biphenylyl)-3-aryl-3-phenylpropanothioamides

  • 서영완;김경태
    • Bulletin of the Korean Chemical Society
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    • 제16권4호
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    • pp.356-359
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    • 1995
  • The reaction of 5-aryl-2-phenylisoxazolidine-3-thiones with more than 3 equivalents of anhydrous aluminum chloride in benzene at reflux gave N-(p-biphenylyl)-3-aryl-3-phenylpropanothioamides in good yields. It is conceived that the propanothioamides are formed via the formation of the corresponding N-phenyl-3-aryl-3-phenylpropanothiohydroxamic acids.

마그네슘 용융염전해(溶融鹽電解)를 위한 무수(無水)염화마그네슘 제조(製造) (Preparation of Anhydrous Magnesium Chloride for a Fused Salt Electrolysis of Magnesium)

  • 엄형춘;박형규;윤호성
    • 자원리싸이클링
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    • 제16권1호
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    • pp.37-43
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    • 2007
  • 본 연구에서는 함수염화마그네슘 탈수를 통하여 마그네슘 용융염전해의 원료 물질인 무수염화마그네슘을 제조하였으며, 탈수는 관상로를 이용하여 $350{\sim}580^{\circ}C$ 범위에서 수행하였다. 함수염화마그네슘을 대기중에서 탈수할 경우 모두 산화마그네슘으로 산화되는 것을 알 수 있었으며, 염화수소가스 분위기에서 탈수시켜 무수염화마그네슘을 제조할 수 있음을 확인하였다. 그리고 탈수 온도와 시간이 증가함에 따라 탈수된 무수염화마그네슘의 결정성이 증가하였다. 염화수소가스 분위기에서 탈수가 일어나는 동안 발생되는 미반응 염화수소가스는 모두 염산으로 회수할 수 있었으며, 회수한 염산은 산화마그네슘으로부터 함수염화마그네슘을 제조하는 데에 재사용 가능할 것으로 판단된다.

무가습 가교 가지형 공중합체 전해질 막의 제조 (Preparation of Anhydrous Crosslinked Graft Copolymer Electrolyte Membrane)

  • 노동규;고주환;박정태;서진아;김종학
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.270-273
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    • 2009
  • A comb-like copolymer consisting of a poly(vinylidene fluoride-co-chlorotrifluoro-ethylene) backbone and poly(hydroxy ethyl acrylate) side chains, i.e. P(VDF-co-CTFE)-g-PHEA, was synthesized through atom transfer radical polymerization (ATRP) using CTFE units as a macroinitiator. Successful synthesis and a microphase-separated structure of the copolymer were confirmed by proton nuclear magnetic resonance (1H-NMR), FT-IR spectroscopy, and transmission electron microscopy (TEM). This comb-like polymer was crosslinked with 4,5-imidazole dicarboxylic acid (IDA) via the esterification of the -OH groups of PHEA and the -COOH groups of IDA. Upon doping with phosphoric acid ($H_3PO_4$) to form imidazole-$H_3PO_4$ complexes, the proton conductivity of the membranes continuously increased with increasing $H_3PO_4$ content. A maximum proton conductivity of 0.015 S/cm was achieved at $120^{\circ}C$ under anhydrous conditions. In addition, these P(VDF-co-CTFE)-g-PHEA/IDA/$H_3PO_4$ membranes exhibited good mechanical properties (765 MPa of Young's modulus), and high thermal stability up to $250^{\circ}C$, as determined by a universal testing machine (UTM) and thermal gravimetric analysis (TGA), respectively.

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유류오염 토양에서 발생되는 VOCs 제거를 위한 분변토의 활용 가능성에 관한 기초연구 (A Fundamental Study on the Application of Cast for Removal of VOCs Produced in the Oil-contaminated Soil)

  • 손희정;천미희;김철
    • 한국환경보건학회지
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    • 제33권5호
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    • pp.456-461
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    • 2007
  • This study was carried out two point view that reuse of sludge and adsorption of benzene, toluene and o-xylene of VOCs in cast, carbonized cast and activated carbon. The cation exchange capacity of cast and carbonized cast were 59.2, 112 meq/100g, respectively. The specific surface were 560, $800m^2/g$, respectively. The average removal rates of benzene by 50g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 15.0, 41.2, 88.2, 99.4% in 60min of retention time. The average removal efficiency of toluene by 50 g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 12.5, 34.2, 88.2, 99.5% in 60 min of retention time. The average removal rates of o-xylene 50 g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 8.8, 28.5, 84.8, 98.1% in 60min of retention time. The adsorption efficiency of test absorbent was in order of Activated Carbon > Carbonized Cast > Cast.

Electrical and rheological properties of chitosan malonate suspension

  • Ko, Young-Gun;Choi, Ung-Su
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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    • pp.345-346
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    • 2002
  • The electrical and rheological properties of a chitosan malonate suspension in silicone oil was investigated by varying the electric fields, volume fractions of particles, and shear rates, respectively. The chitosan malonate susepnsion showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of multiple chains upon application of an electric field. The shear stress for the suspension exhibited a linear dependence on the volume fraction and an electric field power of 1.88. On the basis of the results, the newly synthesized chitosan malonate suspension was found to be an anhydrous ER fluid.

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