• Title/Summary/Keyword: chlorides

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Estimation of Reduction Rate of Airborne Chlorides base on Coastal Distance and Facilities in Incheon Port, South Korea (인천항의 대기 중 비래염분량의 시설물별 특성 및 해안거리에 따른 감소량 추정)

  • Jahe Jung;Jong-Suk Lee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.13-21
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    • 2023
  • In this study, the coastal airborne chlorides were investigated in the Incheon Port, South Korea. Monthly measurements of coastal airborne chlorides were taken for a total of 2 years from September 2021 to August 2023 at 15 locations in North, South, and New Port. We analyzed the distribution characteristics of airborne chloride based on port facilities and measurement environments, as well as the reduction characteristics of the airborne chloride with respect to coastal distance. As a result, the monthly distribution range of the airborne chloride in the North, South, and New Port varied similarly, ranging from 0.4 to 3.3 mdd. Due to the influence of seasonal winds considering the direction of the coastline, both the North Port and South Port had higher the airborne chloride in winter, while the New Port had higher content in summer. The airborne chlorides were higher at locations inside an inland sea compared to those outside an inland sea. This is because the wind coming from the sea passed through the inland sea. Even in the same region with identical coastal distances, there were variations in airborne chloride levels depending on the height above the ground. In tidal zone, the monthly airborne chlorides were significantly higher in the lower part than in the upper part. The rate of decrease equation of airborne chlorides for each port based on the distance from the coastline was derived, and the results showed that as the distance from the coastline increased, the rate of decrease in airborne chlorides was the highest for New Port and the lowest for South Port.

Effects of Various Salts on the Reheating Behavior of Retrograded Rice Starch and Cooked Rice

  • Han, Sung-Hee;Kim, Bo-Reum;Lee, Seog-Won;Rhee, Chul
    • Preventive Nutrition and Food Science
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    • v.16 no.2
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    • pp.157-164
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    • 2011
  • The influence of sodium salts and chlorides at various concentrations (0.05, 0.10, 0.50, and 1.00%) on the reheating behavior of retrograded rice starch and cooked rice was investigated. The degree of gelatinization of the all retrograded rice starch gels and the cooked rice containing sodium salts and chlorides increased after reheating compared to the starches without salt. Gelatinization also showed an increasing trend as the concentration of sodium salts and chlorides increased. The increase of gelatinization after reheating the samples containing sodium salts and chlorides was greater than 38.0%. The reheated retrograded rice starch and cooked rice containing $Na_3PO_4$ showed the lowest set back value and retrogradation rate constant. Among all the samples, the cooked sample containing $Na_3PO_4$ showed the highest increment of gelatinization after reheating. Also, this same sample showed the lowest retrogradation degree.

Synthesis of Polyphenylene-1,2,4-Owadiazoles and Quinone Polymer by the Reactions of Tere- and Iso-Phthalohydroxamoyl Chlorides with Bisdipolarophiles

  • Suck-Ju Hong
    • Journal of the Korean Chemical Society
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    • v.15 no.3
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    • pp.121-125
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    • 1971
  • Tere-and Isophthalohydroxamoyl chlorides were condensed with 1, 4-benzoquinone to afford quinone type polymer with the oxidation of the ring structure. Similarly, tere-and isophthalohydroxamoyl chlorides were condensed with tere-and isophthaldioximes and terephthalonitrile to give crystalline polyphenylene-1,2,4-oxadiazoles, among which the reaction product of terephthalohydroxamoyl chloride with terephthalonitrile in xylene afforded the highest crystallinity.

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Convenient One-Pot Synthesis of Sulfonamides from Thiols and Disulfides Using 1,3-Dichloro-5,5-dimethylhydantoin (DCH)

  • Veisi, Hojat
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.383-386
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    • 2012
  • A convenient synthesis of sulfonamides from thiols and disulfides is described. In situ preparation of sulfonyl chlorides from thiols is accomplished by oxidation with 1,3-dichloro-5,5-dimethylhydantoin (DCH) under Nbenzyl-trimethylammonium chloride and water. The sulfonyl chlorides are then further allowed to react with excess amine in the same reaction vessel.

A Study on the Corrosion Characteristics of Steel Reinforcements Induced by Internal Chlorides in Concrete (콘크리트 내부염소이온에 의한 철근의 부식특성에 관한 연구)

  • 오병환;장승엽;신용석;차수원;김광수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.197-202
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    • 1998
  • The corrosion of steel reinforcements in concrete is of much concern in recent years. The mechanism of corrosion, however, is not clear yet. This study is focused on the corrosion of steel induced by internal chlorides in concrete at early ages. To examine the critical concentration of steel, half-cell potential, chemical composition of expressed pore solutions of mortars and rate of corrosion area were observed with respect to additions of chlorides, types of binders, water-binders ratio.

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Study on the long-term change of Chlorides in the tidal area of river (하천 감조부에 있어서 염분의 장기변동에 관한 연구)

  • 김원규
    • Journal of Environmental Science International
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    • v.3 no.1
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    • pp.11-16
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    • 1994
  • Generally, it is difficult to predict water quality in a tidal river, because tidal flows make the transport phenomena more complicated. The purpose of this study is to clarify long-term mass transport in a tidal river through suggestion of simulation model. A simulation model based on a Lagrangian coordinate system, which has the advantage reducing numerical dispersion, was used to calculate changes in concentration of chlorides. Several field surveys were conducted to verify calculated results. Concludingly, long-term behavior of mas transport in a tidal river can be represented using the model.

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Solvent Effect on the Reactions of DANSYL and BANSYL Chlorides with Substituted Pyridines

  • 성대동;강동효;장정아;박성배;류준하
    • Bulletin of the Korean Chemical Society
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    • v.19 no.5
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    • pp.561-564
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    • 1998
  • Solvent effects on the reactions of DANSYL and BANSYL chlorides with substituted pyridines have been investigated using two parameters of Taft's solvatochromic correlation and four parameters of Kirkwood-Onsager, Parker, Marcus, Hildebrand equation. The acetonitrile molecules accelerate charge separation of the reactants and stabilize the transition state. The coefficient of the solvent parameters provide a good information to predict and to analyze the reaction mechanism. The nucleophilic substitution reaction of DANSYL and BANSYL chlorides with substituted pyridines are ruled by the contribution of the change in dipole moment term and polarity-polarizability term.

Effect of Chlorides on Nitrification Process in a Tidal Section of the River (하천 감조역에서의 질소변환에 있어서 염분의 영향)

  • 김원규
    • Journal of Environmental Science International
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    • v.2 no.3
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    • pp.227-233
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    • 1993
  • Laboratory batch experiments were conducted, using suspended solids and sediments taken. from a tidal section of the Rokkaku river, to study the effect of salinity on nitrification and to estimate kinetic parameters of it. Experimental results indicated much more inhibitation of ;$NO_2$-N oxidation by chlorides than that of $NH_4$-N oxidtion. Nitrifying bactema in sediments were less sensitive to chlorides than those in SS. The change of nitrogen concentration with time was clearly explained with the Monod growth model and the kinetic parameters were obtained by the curve fitting method.

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A Study on the Scaling Deterioration and Resistance to Freezing of Concrete by Containing Chlorides (염화물 함유에 의한 콘크리트의 내동해성 및 표면열화에 관한 연구)

  • Park Joo Houn;Kim Gyu Yong;Kim Han Jun;Kwon Yeong Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.372-375
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    • 2004
  • Scaling deterioration and resistance to freezing of port concrete structures due to the combined effects of chemical actions by containning chlorides and the freeze-thaw action is also a problem which has not yet been fundamentally solved. Furthermore, deterioration of concrete surface was considered as accelerate factor of concrete durability tended to decrease. Therefore, we considered the scaling measuring method and decreasing influence of durability of concrete according to kind of binders, such as OPC, Slag, Slag+Fa, due to freeze and thaw of concrete by containing chlorides. As a results of this study, it was effective method of scaling deterioration and resistance freewing of concrete, and confirmed the salt deterioration resistance effect to use slag binder against to containing chlorides.

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Poly(N,N'-Dichloro-N-ethyl-benzene-1,3-disulfonamide) and N,N,N',N'-Tetrachlorobenzene-1,3-disulfonamide as Efficient Reagents to Direct Oxidative Conversion of Thiols and Disulfide to Sulfonyl Chlorides

  • Veisi, Hojat;Ghorbani-Vaghei, Ramin;Mahmoodi, Jafar
    • Bulletin of the Korean Chemical Society
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    • v.32 no.10
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    • pp.3692-3695
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    • 2011
  • Poly(N,N'-Dichloro-N-ethyl-benzene-1,3-disulfonamide) (PCBS) and N,N,N',N'-Tetrachlorobenzene-1,3-disulfonamide (TCBDA) were found to be a mild and efficient reagent for the direct oxidative conversion of sulfur compounds to the corresponding arenesulfonyl chlorides in good to excellent yields through the oxidative chlorination. The overall process is simple, practical, and it provides convenient access to a variety of aryl or heteroarylsulfonyl chlorides. The mild reaction conditions and the broad substrate scope render this method attractive, and complementary to existing syntheses of aryl or heteroarylsulfonyl chlorides.