• Title/Summary/Keyword: 몰분률

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Risk Assessment of Petrochemical Equipments Using Enhanced RBI Technique (개선된 RBI 기법을 이용한 석유화학설비의 위험도평가)

  • Lee Sang-Min;Song Ki-Hun;Chang Yoon-Suk;Choi Jae-Boong;Kim Young-Jin;Han Sang-In;Choi Song-Chun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.10 s.241
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    • pp.1392-1398
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    • 2005
  • API 581 guideline provides a methodology for calculating the risks of equipments in refinery or petrochemical plant. However, especially in part of the consequence of failure, there is a major limitation of its application to the petrochemical plant directly since only a representative material is considered in calculating the risk while the equipment is composed of numerous materials. The objectives of this paper are to propose an enhanced risk-based inspection (RBI) technique to resolve shortcomings inclusive of the above issue and to assess the risks of typical petrochemical equipments. In this respect, a program incorporating material database was developed to fully incorporate the characteristics of different materials. The proposed RBI program consists of qualitative, semi-quantitative and quantitative risk evaluation modules in which toxic materials as well as representative materials were selected automatically for comparison to those in the current guideline. It has been applied to assess the risks of equipments in ethylene facilities of petrochemical plants. Thereby, more realistic evaluation results were obtained and applicability of the proposed RBI program was proven.

Nucleophilic Displacement at Sulfur Center (XVII). Solvolysis of 2-Anthracenesulfonyl Chloride (황의 친핵성 치환반응 (제17보) 2-염화안트라센 술포닐의 가용매 분해반응)

  • Hyong Tae Kim;Soo Dong Yoh;Ikchoon Lee
    • Journal of the Korean Chemical Society
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    • v.27 no.3
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    • pp.167-177
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    • 1983
  • The kinetics of 2-anthracenesulfonyl chloride in methanol-water, ethanol-water, acetone-water and acetonitrile-water has been studied by electroconductometric method. For media in which water has the same mole fraction, the rate was greater in protic solvent than in dipolar aprotic solvent and it was greater consistently in methanol-water than in ethanol-water over the whole range of solvent composition investigated, while the two rates in acetone-water and acetonitrile-water inverted at about 0.9 of mole fraction of water. Both m value, susceptibility of rate to the ionizing power and n value, solvent participation number in the transition state were much smaller in protic solvent. These values and the activation parameters show that solvolysis of 2-anthracenesulfonyl chloride proceeds by $ S_N2$ mechanism.

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The Effect of Surfactant on Controlled Release of Amino acids Through Poly(2-Hydroxyethyl Methacrylate) Membrane (Poly(2-Hydroxyethyl Methacrylate)막을 통한 아미노산의 방출 조절에 대한 계면활성제의 효과)

  • Kim Ui-Rak;Jeong Bong-Jin;Lee Myung-Jae;Min Kyung-Sub
    • Journal of the Korean Chemical Society
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    • v.37 no.1
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    • pp.22-35
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    • 1993
  • The transport phenomena of the free amino acids through poly(hydroxyethyl methacrylate)[P(HEMA)] have been investigated with and without various kinds of surfactants solution and in the mixed surfactants solution. Glutamine has the highest diffusivity among 4 amino acids at 1CMC of cetyldimethylethylammonium bromide(CTABr) surfactant. Glutamic acid is not affected by the concentration of CTABr. Methionine and Lysine shows slight decreased diffusivity at 0.5 CMC, but increase its diffusivity at 1CMC and 2CMC due to the structure change of membrane and the viscosity change of surfactant solution. Glutamic acid has the highest diffusivity among four amino acids at sodium dodecyl sulfate(SDS) and Triton X-100 surfactant. In mixed surfactant solution, each amino acids shows high diffusivity through 45% water content membrane at the 0.5 mole fraction of SDS in the SDS/TX-100 surfactant mixtures. It has been found that not only the property of membrane but also the effects of solute-solvent interactions and solvent effect are very important as the permeation of amino acids occurs through P(HEMA) membrane. The diffusivities of free amino acids through membrane depend upon their molecular shape, size and charge.

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