• Title/Summary/Keyword: 염소

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mtDNA Diversity and Phylogenetic Analysis of Korean Native Goats (한국재래염소의 mtDNA 다양성 및 계통유전학적 분석)

  • Kim, Jae-Hwan;Cho, Chang-Yeon;Choi, Seong-Bok;Cho, Young-Moo;Yeon, Seung-Hum;Yang, Boh-Suk
    • Journal of Life Science
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    • v.21 no.9
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    • pp.1329-1335
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    • 2011
  • Korean native goats, which are characterized by black coat color, have existed on the Korean peninsula for a long time. Until now, there has been no comprehensive investigation concerning their genetic diversity, phylogenetic analysis or origin. In this study, we investigated the genetic diversity and verified phylogenetic status of the Korean native goat using the 453-bp fragment of the hypervariable fragment I (HVI) of mitochondrial DNA (mtDNA) D-loop region from 60 individuals among 5 populations. The Korean native goat showed less haplotype diversity when compared with goats from other countries. In addition, 6 haplotypes that had not been previously reported were verified in this study. In phylogenetic analyses with other country's goats, 10 haplotypes from Korean native goats were classified into mtDNA lineage A. Moreover, in a phylogenetic tree for goats which contained mtDNA lineage A, 8 of 10 haplotypes could be included in a subgroup with goats from Vietnam and an area of China. However, none of the remaining haplotypes belonged to a major group of Korean native goats and were located on different independent positions. These results suggest that almost Korean native goats aligned more closely to China and Vietnam breeds in mtDNA lineage A and there was no gene flow from other mtDNA lineages. Our results will contribute to conservation strategies and genetic breeding of Korean native goats.

Influence of Water-Cement Ratios and Curing Conditions on the Diffusion Characteristics of Chloride Ion in Concrete (콘크리트의 염소이온 확산특성에 미치는 물-시멘트비 및 양생조건의 영향)

  • Bae, Su-Ho;Lee, Kwang-Myong;Kim, Jee-Sang;Jung, Sang-Hwa
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4A
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    • pp.753-759
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    • 2006
  • To predict service life of concrete structures exposed to chloride attack, surface chloride concentration, diffusion coefficient of chloride ion, and chloride corrosion threshold value in concrete, are used as important factors. Of these, as the diffusion coefficient of chloride ion for concrete is strongly influenced by concrete quality and environmental conditions of structures and may significantly change the service life of structures, it is considered as the most important factor for service life prediction. The qualitative factors affecting the penetration and diffusion of chloride ion into concrete are water-cement (W/C) ratio, age, curing conditions, chloride ion concentration of given environment, wet and dry conditions, etc. In this paper the influence of W/C ratio and curing conditions on the diffusion characteristics of chloride ion in concrete was investigated through the chloride ion diffusion test. In the test, the voltages passing through the diffusion cell were measured by accelerated test method using potential difference, and then with the consideration of IR drop ratio the diffusion coefficient of chloride ion for concrete with different W/C ratios were estimated by Andrade's model. Furthermore, under different curing conditions formulas for the estimation of the diffusion coefficient of chloride ion have been proposed by the regression analysis considering the effect of W/C ratio and age.

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Effect of various environmental factors such as concentration of NaClO2, relative humidity, temperature, and time on the production of gaseous chlorine dioxide (다양한 환경조건(NaClO2 농도, 상대습도, 온도, 시간)에 따른 이산화염소 기체의 발생량 변화)

  • Lee, Jeongmin;Lee, Nam-Teak;Ryu, Jee-Hoon
    • Korean Journal of Food Science and Technology
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    • v.51 no.4
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    • pp.404-409
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    • 2019
  • This study was performed to determine the optimum conditions for the production of gaseous chlorine dioxide ($ClO_2$) from aqueous $ClO_2$ (HCl+$NaClO_2$). When 1 N HCl was reacted with various concentrations of $NaClO_2$ (50,000-500,000 mg/mL), the highest concentration (695 mg/L) of gaseous $ClO_2$ was obtained from the aqueous $ClO_2$ containing $100,000{\mu}g/mL$ $NaClO_2$. Next, the effects of relative humidity (RH; 43, 85, and 100%) and temperature (4, 12, and $25^{\circ}C$) on the production of gaseous $ClO_2$ were investigated. It was observed that the concentration of gaseous $ClO_2$ was increased as RH was decreased, or the temperature was increased. Finally, it was confirmed that the amount of gaseous $ClO_2$ was highly correlated ($R^2=0.9546-0.9992$) with the volume of aqueous $ClO_2$. The results of this study provide useful information for designing a sanitization program using gaseous $ClO_2$ under various environmental conditions.

Hazard Assessment on Chlorine Distribution Use of Chemical Transportation Risk Index (화학물질 운송위험지수를 활용한 염소(Chlorine) 유통 위해성 평가)

  • Kim, Jeong Gon;Byun, Hun Soo
    • Korean Chemical Engineering Research
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    • v.52 no.6
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    • pp.755-767
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    • 2014
  • Chlorine is one of the most produced and most used non-flammable chemical substances in the world even though its toxicity and high reactivity cause the ozone layer depletion. However, in modern life, it is impossible to live a good life without using Chlorine and its derivatives since they are being used as an typical ingredient in more than 40 percent of the manufactured goods including medicines, detergents, deodorant, fungicides, herbicides, insecticides, and plastic, etc. Even if Chlorine has been handled and distributed in various business (small and medium-sized businesses, water purification plants, distribution company, etc.), there have been few researches about its possible health hazard and transportation risks. Accordingly, the purpose of this paper is to make a detailed assessment of Chlorine-related risks and to model an index of chemicals transportation risks that is adequate for domestic circumstances. The assessment of possible health hazard and transportation risks was made on 13 kinds of hazardous chemicals, including liquid chlorine. This research may be contributed to standardizing the risk assessment of Chlorine and other hazardous chemicals by using an index of transportation risks.

Diffusion Characteristics of Chloride ion under Single and Combined Attacks in Concrete Structures (콘크리트 구조물의 단일 및 복합열화 환경하에서의 염소이온 확산특성)

  • 오병환;강의영;인광진;이성규;서정문
    • Journal of the Korea Concrete Institute
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    • v.14 no.5
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    • pp.708-717
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    • 2002
  • Durability is a major concern in the design and construction of concrete structures which are located in the sea environments. In particular, the combined action of chlorides, sulfates, and carbonation nay influence greatly the deterioration behavior of concrete structures. The purpose of the present study is to explore the diffusion characteristics of chloride ions in concrete structures under combined deterioration conditions. The present test results indicate that the chloride penetration into concrete structures is more pronounced under combined attacks of chlorides, sulfates and carbonation. The diffusion coefficients and surface chloride contents were found to increase under combined multiple deterioration conditions. The present study provides quantitatively the penetration and diffusion characteristics of chloride ions in concrete structures under various deterioration conditions. The results of present study may be efficiently used for the realistic design of concrete structures under combined deterioration conditions.

Analysis of chloride penetration in the marine concrete pier (해양환경 콘크리트 교각의 염소이온 침투해석)

  • Kim, Ki-Hyun;Cha, Soo-Won;Jang, Sung-Yup;Park, Byoung-Sun;Chang, Sung-Pil
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.549-552
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    • 2008
  • Corrosion of reinforcing steel is prohibited under normal condition by the alkalinity of the pore water in the concrete. But the probability of steel corrosion becomes higher when the chloride ions are introduced into the concrete. Steel corrosion is decisive factor for the determination of service life of the marine concrete structures because chloride ions are abundant in the sea. In this paper, chloride penetration analysis for the rectangular pier in the marine environment is performed considering the diffusion movement of chlorides. Result reveals that the chloride concentration in the corner bar is higher than that of in the side bar with rectangular pier. Also the time to the specified accumulation of chloride in the corner bar is much shorter than that in the side bar. Because the corrosion initiation time of corner bar is half as much as that of side bar, service life for the rectangular pier in marine environment should be determined with respect to the coner bar.

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Leaching of Ruthenium by Electro-generated Chlorine Gas by Electrochemical Method (전기화학법(電氣化學法)에 의해 생성(生成)된 전해생성(電解生成) 염소(鹽素)를 이용한 루테늄의 침출(浸出))

  • Ahn, Jong-Gwan;Lee, Ah-Rum;Kim, Min-Seuk;Ahn, Jae-Woo;Lee, Jae-Ryeoung
    • Resources Recycling
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    • v.22 no.6
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    • pp.55-63
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    • 2013
  • In this study, a electrochemical-chemical combined dissolution technology was conducted by electro-generated chlorine to obtain ruthenium solution from ruthenium metal. To find out the optimum leaching conditions of ruthenium in chloride solution, this leaching process was carried out on the variation of pH, reaction time, temperature and applied voltage at the electro-generated chlorine system in the reaction bath. Also, ozone generator was used to obtain ruthenium(III) chloride solution to increase the leaching rate. The optimum condition was observed at pH 10.0, $40^{\circ}C$ within 1 hr of reaction time that more than 88% of ruthenium(III) chloride dissolved.

Influence of Dissolved Organic Nitrogen on Organic Chloramine Formation during Chlorination (염소 소독시 DON이 유기성 클로라민 생성에 미치는 영향)

  • Lee, Won-Tae
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.7
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    • pp.481-484
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    • 2011
  • Although formation of organic chloramines have been studied for decades, most of them have involved model organic compounds (e.g., amino acids) but not naturally occurring organic nitrogen in water. This study investigated formation of organic chloramines during chlorination of 16 natural organic matters (NOM) solutions which were isolated from surface water and contained dissolved organic nitrogen (DON). Organic chloramine yields per chlorine consumption was $0.25mg-Cl_2/mg-Cl_2$. Upon chlorination of NOM solutions, organic chloramines were rapidly formed within 10 minutes. The average organic chloramine yields upon addition of chlorine in to NOM solutions were $0.78mg-Cl_2/mg-DON$ at 10 minutes and $0.16mg-Cl_2/mg-DON$ at 24 hours. Organic chloramine yields increased as the dissolved organic carbon/dissolved organic nitrogen (DOC/DON) ratios decreased. Chlorination of molecular weight (10,000 Da) fractionated samples showed that the influence of DON molecular weights on the organic chloramine formation was minimal.

Disinfection Effects of Chlorine and Monochloramine on Campylobacter jejuni (Campylobacter jejuni에 대한 염소 및 Monochloramine의 살균효과)

  • 윤만석;오학식;김치경
    • Microbiology and Biotechnology Letters
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    • v.17 no.6
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    • pp.539-544
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    • 1989
  • Campylobacter jejuni, bacterial agent causing human diarrhea, were studied for their disinfection effects with chlorine and monochloramine. The cells treated with the chemical agents were observed by scanning electron microscopy to know their morphological and structural changes. The proteins and DNA in the chemical-treated cells were also examined by gel electrophoresis for structural changes. When C. jejuni were chlorinated at concentrations of 0.5 and 1.0 mg/l for 15 minutes, the organisms were disinfected by 4 and 6 log, respectively. Those disinfection effects were higher at acidic pH, while lowered at neutral and alkaline values of pH. The effects of monochloramine were lower than those of chlorine at the game concentration for the same period of reaction time. The shapes of C. jejuni cells treated with the agents appeared to be deformed from spiral rod into spherical forms, showing some destruction in surface structure of the cells. Some of the proteins and DNA of the chlorinated cells did not appear in the gel electrophoresis when the chlorination was at concentration of 10 mg/l or higher.

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Disposable Strip-type Sensors for Detection of Free Chlorine (유리염소 측정을 위한 일회용 스트립 센서)

  • Kim, Seung Ki;Kang, Tae Young;Cha, Geun Sig;Nam, Hakhyun;Shin, Jae Ho
    • Journal of the Korean Electrochemical Society
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    • v.15 no.4
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    • pp.242-248
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    • 2012
  • The measurement of residual chlorine as a disinfectant is very important to ensure the safety against the pathogenic microbes and to suppress injection. The portable free chlorine sensor was fabricated with a disposable strip format by a screen printing method. The strip sensors prepared with a carbon-Ag/AgCl(cathode-anode) combination exhibited less interfering responses towards combined chlorine species(especially $NHCl_2$) and oxygen than the sensors prepared with other metals(i.e., gold and platinum). Free chlorine was determined chronoamperometrically with carbon-based electrodes at an applied potential of -0.3 V(vs. Ag/AgCl). A channel was built on the strip-type electrode for easy sampling, and the resulting strip sensors were employed to determine the concentrations of residual free chlorine.