• Title/Summary/Keyword: Chemical Change

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The properties of mortar using ground granulated blast-furnace slag (고로슬래그 미분말을 사용한 모르타르의 물성)

  • 김태형;김종인;최영화
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04a
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    • pp.105-110
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    • 1998
  • The propose of this study is to examine the mechanical properties of mortar using ground granulated blast-furnace(GGBF) slag. In this study, the mortar replaced by varying fineness and content of GGBF slag is investigated through the change of compressive strength, chemical resistance and weight loss. As the result, it has been found that GGBF slag increase somewhat higher flow value and compressive strength. In addition, the chemical resistance of motar using GGBF slag shows higher flow that of motar not containing GGBF slag.

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Origin of Exo/Endo Selectivity in the Intramolecular Diels-Alder Reaction

  • Yan, Shihai;Ryu, Do-Hyun;Lee, Jin-Yong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2527-2530
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    • 2010
  • The stereoselectivity of the intramolecular Diels-Alder reactions of 1 and its derivatives were investigated by ab initio calculations. The stereoselectivity mainly originates from the steric repulsion and the orbital interactions. The additional s-cis and s-trans conformations by introducing the carbonyl group at the neighbor of diene or dienophile may change the stereoselectivity, hence this kind of substitution can be utilized for stereoselectivive asymmetric synthesis.

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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The Surface Tension and the C. M. C. of the Solution of Dodecylpyridinium Bromide (Dodecylpyridinium Bromide 溶液의 表面張力과 C. M. C.)

  • Han, Man-Un;Lee, Chong-Man;Kim, Tae-Woo
    • Journal of the Korean Chemical Society
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    • v.9 no.3
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    • pp.124-127
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    • 1965
  • The surface tension of the solution of dodecylpridinium bromide was measured by the ring method over the range $25^{\circ}\; to\; 45^{\circ}C.$ The critical micelle concentration was determined from the change of the surface tension of solution with concentration. The temperature dependence of the critical micelle concentration was also investigated. The result was compared with Adderson and Taylor's data determined by the conductivity method.

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A Process Hazard Analysis using HAZOP in K Chemical Plant (HAZOP에 의한 K화학공장의 공정위험성 평가)

  • 이동형;배기웅;남소영;남경돈;이준열
    • Journal of the Korea Safety Management & Science
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    • v.2 no.1
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    • pp.129-139
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    • 2000
  • Hazard and operability Review(HAZOP) is widely used as a process safety analysis which systematically identifies potential process deviations and settles the problems. In this paper, we carried out a process hazard analysis using HAZOP in K chemical plant. As a result, we showed that the plant could be operated more saftly and be saved a lot of money by eliminating several existing hazardous factors through the change of processes and designs.

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Urea Receptors which Have Both a Fat Brown RR and a Nitrophenyl Group as a Signaling Group

  • Lee, Sung-Kyu;Kang, Jong-Min
    • Bulletin of the Korean Chemical Society
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    • v.30 no.12
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    • pp.3031-3033
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    • 2009
  • A new colorimetric anion sensor 1 has been synthesized based on both Fat brown RR dye and a nitrophenyl group. This new receptor 1 could recognize the presence of fluoride ion effectively and selectively by the change of color of solution. In addition, receptor 1 shows higher affinity for acetate, dihydrogenphosphate, and hydrogensulfate than the other anions such as chloride, bromide, iodide, perchlorate, and nitrate in acetonitrile.

Activated Clay Maunfacturing Studies(II) Studies on the Estimation of Acid Clay Structure (活性白土에 關한 硏究(제II報) 酸性白土의 構造 推定에 關하여)

  • Son, Sun-Kwan;Ko, Myoung-Won
    • Journal of the Korean Chemical Society
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    • v.14 no.4
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    • pp.309-319
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    • 1970
  • Composition of Acid Clay, the raw material for activated clay manufacturing, was investigated to develop useful data in deciding activation condition. Speculations on components and structure of activated clay were also made in order to see how included components of raw materials change during activation process. And a study was made on relations between structure of activated its adsorptivity. For this research, theremogravimetric analysis, X-ray differaction analysis and calculation of adsorptive index were carried out.

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