• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.264-266
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• 2007

• Food Science of Animal Resources
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• v.28 no.3
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• pp.301-305
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• 2008

This study was carried out to develop an accurate and rapid analysis method to measure the contents of iodide and chloride in infant formula using an ion selectivity electrode. The infant formula SRM 1846 (Standard Reference Material 1846, NIST, USA) was used as a CRM (Certified reference material). Samples were dissolved in water with 3% acetic acid and filtered through filter paper and adjusted to pH 7.0 with 0.1N NaOH. At pH 7.0, the iodide content of the CRM was $1.04{\pm}0.03\;mg/kg$ compared to the specification of $1.11{\pm}0.1\;mg/kg$ of CRM, and the recovery was $93.7{\pm}2.7%$. The chloride content was $5114.3{\pm}240\;mg/kg$ compared to the specification of $4,920{\pm}300mg/kg$ of CRM, and the recovery was $103.9{\pm}4.9%$. Ion selectivity electrodes could be successful1y used to determine the concentration of iodide and chloride ions in infant formula by a simple and rapid pretreatment of sample matrixes.

• Journal of the Korean GEO-environmental Society
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• v.12 no.8
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• pp.51-57
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• 2011

Surface water at the lower part of the Seom-jin river has a high salinity because the erosion at river bottom has made sea water move upstream continuously since 1978. The effect of underground dam on the prevention of sea water intrusion was modelled in this study. Present chloride concentration in surface water decreases exponentially along a river and in groundwater is about one-tenth of surface water's. The finite element method model, FEFLOW, was conducted on the assumption that the underground dam with a height of 25m over a bedrock is located under a water surface at the site of 4.6km from an estuary. The result shows that the position with chloride concentration of 0.25psu moves downstream from the sites of 25km to 22km, if an enough sedimentation with 5m thickness happens in the upper reservoir of underground dam. On the other side, the underground dam is little effective for the prevention of sea water intrusion in case of non-sedimentation.

• Journal of the Korea Concrete Institute
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• v.16 no.4 s.82
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• pp.485-492
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• 2004

In this study, ASTM C 1202 which is most commonly used for evaluating the penetration resistance into the concrete is reviewed. The test results by ASTM C 1202 showed that the passed charge could be underestimated as the $OH^-$ ion concentration in the concrete is lowered when the concrete is mixed with the admixtures. Therefore, the modified method using the distilled water was proposed in the paper. According to the test results, the modified method is not susceptible to $OH^-$ ion and temperature rise. In addition, the long term emersion test for the concrete mixed with the admixtures in the NaCl solution showed that the chloride diffusion coefficient tested by the modified method have higher correlation compared to the conventional ASTM method.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.206-213
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• 2024

The present study concerns the inhibition of Calcium Nitrite Inhibitor(Ca(NO₂)₂) in mortar contaminated by chloride ions. Thus, the corrosion resistance and chloride transport were measured for the mortar containing calcium nitrite inhibitor. As a result, an increase in the dosage of calcium nitrite inhibitor resulted in an increase in the chloride threshold concentration for reinforcement corrosion, while the rate of chloride transport was accelerated. However, the calcium nitrite inhibitor could not guarantee the time to corrosion, due to the increased mobility of chlorides. To ensure the passivity of steel, the dosage of calcium nitrite inhibitor must exceed a certain dosage, ranging from 2.0~3.0 % by cement weight.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.156-158
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• 1998

원자력 발전소에서 사용하는 1차 냉각수에 대해 살펴보면, 일차냉각수의 pH는 5~8 범위이며, 수질기준은 염소이온과 불소이온이 0.15 ppm, 현탁고형물 이 0.2 ppm이나 실제 농도는 기준치보다 훨씬 낮은 매우 순수한 상태로 유지된다. 다만, 핵분열 반응도를 제어하기 위해 주입되는 붕소가 수백 ppm정도, pH를 조절하기 위해 부가되는 리튬의 1 ppm정도 포함되며, 그밖에 1ppm 정도의 실리카가 포함될 수 있다. 붕산으로 포화 운전되는 이온교환 수지탑 내에서는 붕산보다 이온선택도가 낮은 실리카는 이온교환수지에 흡착되지 않기 때문에 발전소의 가동년수의 증가에 ㄷ아라 원자로 냉각제의 실리카 농도는 점차 증가하게 되었다.

• Journal of the Korean Electrochemical Society
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• v.2 no.4
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• pp.195-201
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• 1999

The repassivation characteristics of Fe-Cr steels in deaerated 0.1 M $Na_2SO_4$ solution have been investigated with the variation of Cr content, applied potential and Cl- concentration. In the absence of chloride ion, abrading electrode test showed that, slope -n, of log i=k -n log t, a parameter of repassivation rate, approached to -1, regardless of Cr content but as Cr content increased, repassivation current density decreases with increasing Cr content. A.C. Impedance spectroscopy showed that the charge transfer resistance of passive film became higher as Cr content and applied potential increased. However, in the presence of chloride ion, it was observed that chloride ion suppressed the passive film formation, whose effect became greater with increasing applied potential.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.265-265
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• 2015

Zinc Oxide 층은 역구조 유기 태양전지(Inverted Organic Photovoltaics, IOPV)에서 전자 수집 층으로 사용되는데, 전자 수집 및 전기 전도도 증가를 위하여 일반적으로 3차원 나노 구조체 및 양이온이 도핑된 Zinc Oxide 층이 사용된다. 본 연구에서는 저온 3차원 나노 구조체 및 음이온이 도핑된 Zinc Oxide 층을 적용하였으며, 그 결과 전자 수집 향상, 전기 전도도의 증가에 의하여 광전변환 효율(Power Conversion Efficiency, PCE)이 향상됨을 확인할 수 있었다.

• Journal of Life Science
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• v.20 no.12
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• pp.1906-1909
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• 2010

Acid and halide ion catalyses for the hydrolysis of benzenesulfinamides were kinetically investigated. The rates of hydrolysis increased with increasing concentration of both acid and halide ions and also showed to speed up as the electron donating ability of the benzenesulfinyl moiety and the electron withdrawing ability in the leaving group increased. The reactivity of halide ions was in the order of $Br^-$ > $Cl^-$. The reaction mechanism may be accommodated by including a hypervalent intermediate and sulfonium cation.

• Clean Technology
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• v.21 no.1
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• pp.45-52
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• 2015

We have introduced switching poles in the conventional electrolysis for the removal of ammonia in aquaculture wastewater to prevent the fouling on the electrode surface by the deposition of insoluble metallic compounds. We have also tried to locate the optimal period of switching poles considering the effect of the current loss during switching poles on the free chlorine generation. First, we have observed the decrease of free chlorine generation with the decrease of the period of switching poles due to the expected current loss, and this would lead to the decrease of ammonia removal efficiency. Meanwhile, the measurement of calcium and magnesium concentration in wastewater vs. the period of switching poles have demonstrated that a properly low level of fouling on the electrode surface could be retained with a period of switching poles of less than 60 sec by the decomposition of metallic compounds during switching poles. In a summary, we have optimized the period of switching poles to gain a high level of free chlorine generation and a high level of fouling prevention on the electrode at the same time.