• 제목/요약/키워드: chlorides

검색결과 454건 처리시간 0.022초

고농도 염화물을 함유하는 혼합시멘트 계에서 철근부식에 따른 미세구조의 변화와 전기화학적 특성 (Microstructure modification and electrochemical properties of steel corrosion in the blended cement systems containing internal chlorides)

  • 나종윤;이승헌;김창은
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.131-134
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    • 1999
  • Microstructure modification and electrochemical properties are investigate to estimate the effects of internal chlorides on the steel corrosion in the blended cement systems. According to the test results, slag cement system showed high chloride binding capacity and low corrosion rate. The impedance data showed three distince arcs from lowest(mHz) frequency to highest (MHz) frequency due to product layer, interfacial reaction and bulk matrix. Through the microstructural investigation, fine steel-matrix interface of slag cement system was observed but rough steel-matrix interface of OPC system was observed. Friedel's salt was thought that the substantial material contributed to the chloride binding of slag cement system.

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LiBr와 CaBr2가 흡착된 알루미나상에서 일어나는 염화 알킬의 브롬화반응 (Bromination of Alkyl Chlorides by LiBr and CaBr2 adsorbed on Alumina)

  • 박영훈;신영문;조범준;김창배
    • 공업화학
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    • 제7권5호
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    • pp.1015-1019
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    • 1996
  • 알루미나에 LiBr와 $CaBr_2$를 각각 흡착시켜 용매가 없는 상태에서 여러 가지 염화 알킬과 반응시켜 좋은 수득률로 해당하는 브롬화 생성물을 얻을 수 있었다. 이러한 높은 반응성은 알루미나에 흡착되어 있는 극소량의 물과 브롬화 금속간의 상호작용이 알루미나 상에서 일어날 수 있기 때문이라는 것을 Differential scanning calorimetry (DSC) 열분석 실험과 문헌을 통하여 고찰하였다.

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Spiroacetal을 포함하는 신고분자의 합성(2) (Syntheses and Properties of New Polymers Containing Spiroacetal Moiety (2))

  • 이종문;최두진;이광섭;조순채;안종렬
    • 한국염색가공학회지
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    • 제4권3호
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    • pp.97-115
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    • 1992
  • In order to improve the processability of rigid rod-like polyspiroacetals without significant loss of their good nature, in this work a few new ideas for molecular design were adopted: (1) Copolymerization for breaking the regularity of polymer repeating units. (2) Incorporation of flexible methylene linkages or spacers in rigid spiroacetal polymer main chain. (3) Derivatization of long flexible side chains onto rigid polymer backbone. On the basis of these ideas, a series of polyspiroacetals were prepared, using the phase transfer catalyst, BTMAC, by interfacial polymerization reactions of spiroacetal monomer (SAB) and disubstituted aromatic acid chlorides or aliphatic diacid chlorides. Physical properties of these polyspiroacetals are discussed in relation to their chemical structure and are compared with those of polyspiroacetals synthesized by several other researchers.

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황의 친핵치환 반응 (제5보). 각종 Sulfonyl Chloride에 대한 EHT 계산 (Nucleophilic Displacement at Sulfur Center (V). EHT Calculations on Sulfonyl Chlorides)

  • 이익춘;김의락;배선호
    • 대한화학회지
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    • 제18권3호
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    • pp.171-174
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    • 1974
  • Sulfonyl chloride $ RSO_2Cl,\;R=C6H_5-,\;CH3-,\;OCH3-$$(CH_3)_2N-$에 대하여 EHT계산을 하였으며 바닥상태의 전자구조 특성과 $S_N$반응성을 논의하였다. 특히 $R=OCH_3$의 경우 Buncel이 제안한 Cl에서의 치환가능성을 검토하였다.

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염해 및 황산염의 복합작용에 따른 염소이온 확산특성의 실험적 연구 (Experimental Study of Chlorides Ion Diffusion Characteristics under Combined Condition of Chlorides and Sulfates)

  • 오병환;김선우;정상화;서정문
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.413-418
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    • 2000
  • The test results on the deterioration process of concrete under single and combined action of chloride penetration have been obtained. Within the test period of 15 weeks, it is seen that the internally penetrated chloride ion contents are slightly less in the combined action of NaCI and $Na_2SO_4$ than the single action of NaCI. Also the theoretical prediction of chloride penetration based on measured diffusion coefficient agress well with the test data of single deterioration process but disagress with that of combined process. Therefore it should be needed that improved chloride diffusion model for the combined deterioration process.

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Kinetic Studies on the Halide Exchange Reactions of Some Substituted Benzyl Chlorides

  • Lee, Ikchoon;Lee, Bon-Su;Yie, Jae-Eui
    • Nuclear Engineering and Technology
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    • 제3권4호
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    • pp.198-202
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    • 1971
  • 방사성동위원소로 표지된 할라이드 이온과 염화벤질간의 할로겐 교환반응을 아세톤 용액에서 반응속도론적으로 연구하였다. 결과로 전보에서 얻은 결론대로 교환반응속도가 기질과 할라이드 이온의 편극화율에 의하여 좌우됨을 알았다.

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Dansyl, Bansyl, Dsbsyl Chloride의 친핵성 치환반응 (Necleophilic Substitution Reaction of Dansyl, Bansyl, Dabsyl Chloride)

  • 김문식;채기수
    • 한국식품영양학회지
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    • 제5권1호
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    • pp.23-32
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    • 1992
  • Kinetic studies of nucleophilic substitution reactions of dansyl, bansyl, dabsyl chlorides with pyridines have been investigated at $0^{\circ}C$ in a range of methanol-acetonitrile binary solvent mixtures. The order of magnitude for reactivity of substrates with pyridines in the same reaction condition is dabsyl chloride>dansyl chloride> bansyl chloride. The value of $\rho$n(-2.29~ -4.66) and $\beta$(0.537~0.901) associated with a change substituent in the nucleophile are large and indicate a relatively advanced bond formation in the transition state. Solvatochromic correlations were predicted the increase of bond formation transition state according to the increasing MeCN contents, showing the greater contribution of polarity polarizability ($\pi$*) than hydro-gen bond donar acidity($\alpha$). We conclude that the reactions of dansyl, bansyl, dabsyl chlorides with pyridines proceed via associative Sn2 type reaction mechanism.

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제설제의 염화물과 동결융해의 영향을 동시에 받는 교량구조물 콘크리트 바닥판의 열화특성 (Deterioration Properties for the Concrete Decks of Bridge Structure Effected Simultaneously on the Chlorides of De-icing Salts and Freeze-Thaw)

  • 신승문;박주경;선윤숙;최성민;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2007년도 춘계학술논문 발표대회
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    • pp.137-139
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    • 2007
  • Recently, the research on durability of concrete proceed rapidly in the building industry. Deterioration due to do-icing salts occurs in practice in bridge structure, dike, barrier and similar structure. This paper reports the results of effect of chlorides on the freeze-thaw properties of concrete bridge deck in winter. The case fresh water condition where the concrete will receives a freez-thaw effect compared to decrease of durability quotient a lot occurs is a possibility of knowing from brine condition.

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Synthesis and Cycloaddition Reactions of N-Aryl-2-furohydrazonyl Chlorides

  • S, Shawali-Ahmad;M, Hassaneen-Hamdi;A, Ibrahim-Hossin
    • Archives of Pharmacal Research
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    • 제13권2호
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    • pp.126-131
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    • 1990
  • The novel N-phenyl-2-furohydrazonyl chloride 4A and its p-nitro analog 4B have been prepared and identified. The cycloaddition reactions of nitrilimines 5A and 5B, derived by base catalyzed dehydrochlorination of 4A and 4B respectively, to a variety of dipolarophiles were investigated. The results showed that 4A and 4B are usuful precursors for synthesis of differently substituted 3-(2-furyl)-2-pyrazoline derivatives and their pyrazoles and analogs.

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Solid-phase Parallel Synthesis of a Novel N-[Alkylsulfonamido-spiro(2H-1-benzopyran-2,4-piperidine)-6-yl] substituted Amide and Amine Drug-like Libraries

  • Kim, Ji-Hye;Gong, Young-Dae;Lee, Gee-Hyung;Seo, Jin-Soo
    • Bulletin of the Korean Chemical Society
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    • 제33권1호
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    • pp.128-136
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    • 2012
  • We report the solid-phase library construction of 222 number of a novel N-[alkyl sulfonamido-spiro(2H-1-benzopyran-2,4-piperidine)-6-yl] substituted amide 1A and amine 1B derivatives. The polymer-bound N-[alkylsulfonamido-spiro(2H-1-benzopyran-2,4-piperidine)-6-yl] substituted amide 9 and amine 10 derivatives were obtained by first diversity generation with various acid chlorides and alkyl halides. Further reactions on the resins 9 and 10 with substituted sulfonyl chlorides produced the desired N-[alkylsulfonamido-spiro(2H-1-benzopyran-2,4-piperidine)-6-yl] substituted amide 1A and amine 1B analogues.