• Title/Summary/Keyword: chlorine resistance

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Structural Studies of Hydrotalcite Compounds Calcined with Different Temperatures by $^{27}Al$ Solid-state NMR Spectroscopy

  • Park, Tae-Joon;Kim, Yong-Ae
    • Journal of the Korean Magnetic Resonance Society
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    • v.11 no.1
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    • pp.42-47
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    • 2007
  • Several hydrotalcite compounds calcined with different temperature for applications in a chlorine resistant textile were prepared, and its structural changes in dependence on the temperature were studied by using $^{27}Al$ solid-state nuclear magnetic resonance(NMR) spectroscopy. We found that the Al coordination was partly lowered from octahedral to tetrahedral site as the calcined temperature goes up. And we also investigated the hydrotalcite-treated textile for chlorine resistance by using $^{27}Al$ solid-state NMR spectroscopy.

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The Extraordinary Route of Chlorine Pre-Substitutional Doping on Graphene/Copper Substrate

  • Pham, Viet Phuong;Kim, Kyong Nam;Jeon, Min Hwan;Lin, Tai Zhe;Yeom, Geun Young
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.60-60
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    • 2014
  • By the pre-doping technique on graphene/copper foil, we obtained the pristine sheet resistance and optical transmittance of the chlorine doped-single layer graphene $245{\Omega}/sq$ and 97% at 550 nm wavelength, respectively. X-ray photoelectron spectroscopy revealed that an extremely high Cl coverage of 47.3% of monolayer graphene surface was achieved as the highest surface-coverage graphene doping material ever reported.

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A study on the effect of process parameters on the corrosion resistance of ion plated Tin films with Ti and Ni interlayers. (이온플레팅시 공정조건이 Ti 및 Ni 중간층을 갖는층을 갖는 TiN 박막의 내식성에 미치는 영향에 관한 연구)

  • 하희성;이종민;이인행;이정중
    • Journal of the Korean institute of surface engineering
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    • v.30 no.1
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    • pp.33-43
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    • 1997
  • The effects of process parameters substrate such as substrate current and substrate temperature on the corrosion resistance of ion plated TiN film were investigated. TiN fims were deposited on speed steel on which Ti or Ni hed been previously evaporated. Dense TiN films could be obtained under higher substrate current(1A) and substrate temperature($500^{\circ}C$), whereas TiN films deposited with lower substances current(0.5A) and substrate temperature($300^{\circ}C$) showed porous structure. The corrosion resistances of high speed steel was considerably increased when dense TiN films had been formed on it. The effect of Ti and Ni interlayer on the increase of the corrosion resistance was also significant with dense TiN films, while there was little effect of interlayer on the corrosion resistance when TiN films were porous. the effect of interlayer on the corrosion resistance was more outstanding with Ti then with Ni, because Ti reacts more easily with oxygen to form an oxide layer, and it also shows higher resistance against chlorine containing corrosion media.

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Preparation and Properties of Chlorine-Resistance Loose Reverse Osmosis Hollow-fiber Membrane (내염소성 중공사형 역삼투막(Loose RO)의 제조 및 특성)

  • Kim, Se-Jong;Woo, Seung-Moon;Hwang, Hae-Yong;Koh, Hyung-Chul;Ha, Seong-Yong;Choi, Ho-Sang;Nam, Sang-Yong
    • Membrane Journal
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    • v.20 no.4
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    • pp.304-311
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    • 2010
  • In this study, loose RO hollow fiber membranes using CTA polymer were prepared by phase inversion method and their water purification properties were tested. 1,4-dioxane and LiCl was used as a skin layer formation agent and pore formation agent, respectively. Water flux, salt rejection, chlorine resistance, MWCO and membrane morphology were evaluated as a function of the dope composition. When the membrane prepared using the dope solution of CTA/NMP/1,4-dioxane = 18/72/10 (wt%) with air gap of 30 cm, it shows improved RO performance such as $20.5L/m^2hr$ of water flux, 60% of NaCl rejection, 10,000 ppm/hr of chlorine-resistance and around 5,000 Da of MWCO.

Dioxin Distributions from Combustion: Incinerator Data, Thermodynamic Data, and Kinetic Hypotheses

  • James A. Mulholland;Ryu, Jae-Yong
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.225-228
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    • 1999
  • The formation of dioxin (term used here to refer to both polychlorinated dibenzo-p-dioxins, PCDDS, and dibenzofurans, PCBFs) in combustion processes is of concern because of the extreme toxicities of some of these compounds and because of their resistance to degradation in the environment. The number and location of chlorine substituents differentiate dioxin homologues and isomers, respectively. There are a total of 75 PCDD congeners and 135 PCDF congeners.(omitted)

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Development of Acaricide Resistance and Cross-Resistance in Tetranychus urticae(Acarina: Tetranychidae) (점박이응애의 설비제정항성 발달과 교차저항성에 관한 연구)

  • 김상수;이승찬
    • Korean journal of applied entomology
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    • v.28 no.3
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    • pp.146-153
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    • 1989
  • These studies were conducted to investigate development of chemical resistance in two-spotted spider mite (Tetranychus urticae Koch) trough single selection for a given period of time with five acaricides including carbophenothion and ethion of organo-phosphate compound, dicofol of organo-chlorine compound, cyhexatin of organo-tin compound, biphenthrin of synthetic pyrethroid compound; and to examine cross-resistance among the acaricides to the selected populations. The development of chemical resistance of two-spotted spider mite was greatly varied under single selection of the each five acaricides. The carbophenothion- and the ethion-populations at the 22nd and the 24th selected generations showed 156- and 64.1-fold resistant levels, respectively, as compared with the susceptible population. However, the dicofol population at the 28th selected generation exhibited 39.7-fold resistant level, and the biphenthrin population at the 24th selected generation revealed 25.2-fold resistant level, while the cyhexatin population at the 20th selected generation showed 13-fold resistant level. The carbophenothion-selected population showed high cross-resistance to ethion, and low cross-resistance to dicofol and biphenthrin. The ethion-selected population revealed also high cross-resistance to carbophenothion. The dicofol-or the biphenthrin-selected populations, however, exhibited moderate cross-resistance to carbophenothion and ethion. Meantime, the cyhexatin-selected population showed high cross-resistance to ethion and carbophenothion.

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Generation of Free Chlorine Using $RuO_2$/ Ti Electrode with Various Amount of Ru (Ru 코팅량에 따른 $RuO_2$/Ti 전극의 염소 발생)

  • Lee, JunCheol;Pak, DaeWon
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.11
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    • pp.715-719
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    • 2012
  • We investigated the effects of electrochemical characteristics and generation of chlorine by the different amount of Ru coating which was prepared for $RuO_2$/Ti electrode coated with 1.5 mg, 2.5 mg, 5.5 mg, 8.5 mg Ru per unit area ($cm^2$). As a Result of the cycle voltammetry experiments, chlorine overvoltage of Ru-coated electrodes showed to be the nearly sustained value of approximately 1.15V (vs. Ag/AgCl). By contrary, According to the results of the AC impedance spectroscopy and potentiodynamic polarization tests, the amount of Ru per unit area ($cm^2$) included 2.5 mg, 3.5 mg as $RuO_2$/Ti offered the highest levels of durability which was electrode resistance and corrosion rate appeared to be $0.4582{\Omega}$, $0.5267{\Omega}$ and 0.082 mm/yr, 0.058 mm/yr, respectively. It was also observed that generation of chlorine coated with 3.5 mg per unit area ($cm^2$) was the highest value of 15.2 mg/L.

Property Evaluation of Breathable Blend Fabric of MPCE Copolymer and Wet Coagulated Polyurethane (MPCE copolymer와 습식 폴리우레탄의 블렌드에 의한 투습방수 나일론 직물의 제반 물성변화에 관한 연구)

  • Yi, Jong-Woo;Chae, Ei-Jung;Bae, Jin-Seok
    • Textile Coloration and Finishing
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    • v.26 no.4
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    • pp.322-330
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    • 2014
  • The phospholipid-based MPCE(2-Methacryloxyethyl Phosphoryl Chlorine) copolymer was mixed with wet polyurethane for coating of nylon fabrics. The substitution rate of water in coagulation bath with DMF was changed under control of the size of formed hydrophilic microporous cell enable to manufacture excellent breathable, anti-bacterial and moisture control fabrics. Biocompatible property, vapor permeability, hydrostatic pressure, moisture management and anti-bacterial property were investigated for treated nylon fabrics. In result, increased moisture transmission rates, decreased water resistance and outstanding moisture control property could be confirmed by enhanced hydrophilicity of wet-coated nylon fabric with MPCE copolymer.

Detection and Distribution of the Pathogenic Bioagent Aeromonas (Gamma-Proteobacteria) in Water Supplies of Seoul (서울시 상수계통에서 병원성균 Aeromonas (감마-프로테오박테리아) 분포연구)

  • Lee, Eun-Sook;Lee, Mok-Young;Han, Sun-Hee;Ka, Jong-Ok
    • Korean Journal of Microbiology
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    • v.43 no.2
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    • pp.106-110
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    • 2007
  • The detection and distribution of Aeromonas in water supplies were investigated by using the USEPA Method 1605. Water samples were collected from the Han River, finished waters and tap waters supplied from Water Treatment Plants in Seoul monthly from July 2002 to December 2003. Aeromonas species in each water sample were quantified based on the development of yellow colonies on the surface of membrane filter using a selective medium (Ampicillin-Dextrin Agar with Vancomycin). The Quality Control (QC) for this study met the acceptance criteria of Method 1605. The concentrations of Aeromonas species in surface water samples ranged from $1.0{\times}10^{0}\;to\;9.8{\times}10^{3}\;CFU/ml$. Aeromonas species were found only in one tap water sample with concentration of 1 CFU/500 ml. No Aeromonas species were found in any finished water samples. Aeromonas species detected here were identified as A. salmonicida(51%), A. caviae(4.7%), A. schubertti(3.4%), A. sobria(3.8%), A. hydrophila(2.1%), and A. ichithiosmia(0.4%). A. salmonicida was the dominant species, which is of no significance to human health. Chlorine resistance of A. salmonicida was evaluated and as a result, 99.99% of A. salmonicida decreased after 30 seconds exposure at residual free chlorine 0.2 mg/L. These suggest that the waters supplied in Seoul may be safe against the pathogenic agent Aeromonas.