• Title/Summary/Keyword: Chlorides

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

  • 나종윤;이승헌;김창은
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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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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Bromination of Alkyl Chlorides by LiBr and CaBr2 adsorbed on Alumina (LiBr와 CaBr2가 흡착된 알루미나상에서 일어나는 염화 알킬의 브롬화반응)

  • Park, Yeong Hoon;Shin, Young Mun;Cho, Beom Jun;Kim, Chang Bae
    • Applied Chemistry for Engineering
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    • v.7 no.5
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    • pp.1015-1019
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    • 1996
  • Several alkyl chlorides were brominated using LiBr and $CaBr_2$ adsorbed on alumina in the absence of solvent. The yields of alkyl bromides were fairly high. Such a high reactivity by these bromide salts might be due to the interaction of minute amount of water and the salt on alumina. Differential scanning calorimetry (DSC) thermogram was provided and discussed.

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

  • 이종문;최두진;이광섭;조순채;안종렬
    • Textile Coloration and Finishing
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    • v.4 no.3
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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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Nucleophilic Displacement at Sulfur Center (V). EHT Calculations on Sulfonyl Chlorides (황의 친핵치환 반응 (제5보). 각종 Sulfonyl Chloride에 대한 EHT 계산)

  • Lee Ikchoon;Kim, Ui Rak;Bae, Seon Ho
    • Journal of the Korean Chemical Society
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    • v.18 no.3
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    • pp.171-174
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    • 1974
  • The extended Huckel calculations have been conducted on sulfonyl chlorides $ RSO_2Cl,\;R=C6H_5-,\;CH3-,\;OCH3-$. Results are discussed using ground state electronic structures. $S_N$ reactivity has been discussed using calculated reactivity indices. Particularly, which the substitution of chlorine is take placed or not on $ROSO_2Cl$ in which is suggested by Buncel et al., is discussed by means of some basis on the MO theoretical ground.

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

  • 오병환;김선우;정상화;서정문
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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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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    • v.3 no.4
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    • pp.198-202
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    • 1971
  • Kinetic studies on the halide exchange reactions of some substituted benzyl chlorides have been carried out using radioisotope tracer halide ions. Results are consistent with our previous conclusion that the rates of halide exchange reactions in acetone with arylmethy halides are dictated by the porarizabilities of both substrate and nucleophile.

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

  • 김문식;채기수
    • The Korean Journal of Food And Nutrition
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    • v.5 no.1
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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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Deterioration Properties for the Concrete Decks of Bridge Structure Effected Simultaneously on the Chlorides of De-icing Salts and Freeze-Thaw (제설제의 염화물과 동결융해의 영향을 동시에 받는 교량구조물 콘크리트 바닥판의 열화특성)

  • Shin, Seung-Moon;Park, Ju-Kyung;Sun, Yun-Suk;Choi, Sung-Min;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.04a
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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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    • v.13 no.2
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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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    • v.33 no.1
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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.