• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.77-80
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• 2018

Silver nanoparticles with various sizes were synthesized using ionic liquids. In order to conduct more efficient research, experimental methods and results were analyzed statistically. First, effects of five different parameters including the reaction time, temperature, NaOH concentration, reducing agent and ionic liquid amount on the size of silver particles were investigated. As a result, the effects of time and temperature were negligible. The experimental conditions for the other three factors were then statistically constructed. From XRD analyses, the particles synthesized under all conditions had a pure silver crystal structure. Sizes of the synthesized silver particles were also analyzed by HR-SEM. In the three synthetic conditions, NaOH concentration had the greatest influence on determining the size of silver particles and the reducing agent concentration was relatively minute. Synthesis conditions of silver particles with various sizes were presented by using statistical methods with respect to NaOH and ionic liquids. In addition, the sizes of silver particles according to three experimental conditions were derived by the mixture method.

• Journal of the Korean Ceramic Society
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• v.34 no.1
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• pp.13-22
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• 1997

Water-soluble phosphate glasses containing Ag and Cu ion were prepared through melting process. Dis-solution characteristics, bactericidal effect and cytotoxicity were investigated with composition and time in D. I. water using the powdered sample. Surface change were observed with increasing dissolution time us-ing the bulk specimen. Dissolution amount was maximum at the molar Ag:Cu ratio of 1 and increased with increasing time. The behavior of dissolution was total dissolution from the early stage. But no new layer was observed at the glass surface during dissolution. The bactericidal effect for pseudomonas sp, e. coli, sta-phylococcus aureus, and salmonella increased with increasing dissolution amount and therefore great bac-tericidal effect appeared. The result of cytotoxicity experiment to L929 showed that solution with more than 10 ppm of Ag ion had strong cytotoxicity.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.3
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• pp.15-21
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• 2016

This experiment was conducted to test desorption and recycling characteristics for silver ion adsorbed into waste coffee grounds by using various desorbing agents such as nitric acid, ethylene diamine triacetic acid (EDTA) and nitrilo triacetic acid (NTA). It is appeared that the highest desorption efficiency for silver ions was obtained as about 97.8 % by 1.0 M of nitric acid solution. Also, in the case of less than 1.0 of the ratio of solid and liquid (S/L) (g/L), silver ions adsorbed onto coffee grounds was desorbed as about 98~100 %, and most of desorption process was completed within 60min. In addition, adsorption capacity of reused waste coffee grounds for silver ions was highly maintained as about 43.9 mg/g until the $2^{nd}$ cycle, as compared with the adsorption capacity with 45.9 mg/g of the adsorption capacity for virgin waste coffee grounds.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.223-229
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• 1986

These studies were investigated ionic balance of leaves from different stalk positions of tobacco plant (cv. NC82) grown on pots supplied with nitrate salts solution in the phytotrone. The results of studies are summerized as follows: 1. In comparision with the leaves along the stalk positions, lower position contained higher proportion of total cation and total anion including organic acid, but their concentration lessened gradually at the upper stalk. The ratio in amounts of inorganic cations and anions in leaf laminae depended on their stalk positon, being more than three times in the fifth, but becoming about 1.3 in the tenth. 2. Inorganic cations in the laminae were mostly $K^+$, $Ca^{{+}{+}}$, and $Mg^{{+}{+}}$, comprising about 80% of total with the first two regardless of their stalk positions. Among these two ions $Ca^{{+}{+}}$ tended to become higher at lower stalks, while $K^+$ was higher in younger and became lower when leaves got older and/or more number of leaves were emerged. 3. Total cations were balanced with inorganic and organic acid anions. Composition of inorganic and organic anions were different along stalk positions, ionic balance was governed by organic acid anions dominantly in older leaves, but by inorganic anions in the younger leaves. 4. The discrepancy in the balance between total cations and anions was more pronounced in the older leaves containing higher amount of cations and organic acids. It was suggested that discrepancy was due to precipitation of oxalate as Ca-salt which was not dissolved in the methylation solution of measurement employed.

• Journal of the Korean Chemical Society
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• v.17 no.6
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• pp.439-443
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• 1973

2-Mercaptothiazoline is very sensitive reagent for silver, which have been used for highly selective amperometric determination of silver. A method is described for the determination of micro-quantity of silver by amperometric titration with 2-mercaptothiazoline in ammonical solution. Direct titration of milligram amount of silver (0.05∼1.00mg) is possible in the presence of a number of foreign ions in ammonical solution containing ethylenediaminetetraacetic acid as masking agent under atmosphere. The interfering elements are gold and platinum. The milligram amounts of silver can be determined by the proposed method within an error ${\pm}$5%.

• Journal of the Korean Chemical Society
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• v.20 no.6
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• pp.486-493
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• 1976

The PVC mixed silver iodide pellet was prepared by means of the Infrared Pellet presser and the pellet was used as an indicating membrane electrode, to measure the potentials for various silver ion activities, ranging from $10^{-1}$ to $10^{-6}$ M. The potential responses to silver ion activities were linear and the slope was much close to Nernstian relation as compared with that of the pure silver iodide pellet membrane electrode and the PVC coated silver iodide pellet membrane electrode. The mechanical property and chemical durability of this electrode were found much better than the others. This electrode did not show significant response to the other except silver ion, but had good response to halide ions, i.e., iodide, chloride, bromide and cyanide ions, in the concentration range $10^{-1}$ to $10^{-6}$ M. This electrode could be used as an indicating electrode in potentiometric titrations of single halide ion and also halide mixture with standard solution of silver nitrate.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.135-139
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• 2016

본 연구에서는 동역학적 격자기반 대정준 Monte Carlo (Kinetic Lattice Grand Canonical Monte Carlo, KLGCMC) 모의실험 방법을 이용하여 모델 이온채널 내에서 KCl과 HCl의 이온 전류를 시간의 함수로 구하였다. KLGCMC 모의실험 계산 결과로부터 이온채널의 양이온 선택성이 더 큰 것을 확인 할 수 있었다. 또한 모의실험 결과를 통해 각 이온의 확산계수가 전류에 미치는 영향을 확인 할 수 있었다. $H^+$ 이온은 농도가 매우 작음에도 확산계수가 커 전체 전류에 큰 영향을 미쳤다. 반면에 확산계수가 작은 $K^+$ 이온은 이온채널 안에서 쉽게 흐르지 못하고 정체 되며, $H^+$ 이온의 전류흐름을 방해하는 것을 확인 할 수 있었고, 이로 인해 이온전류의 패턴이 시간에 따라 변화함을 알 수 있었다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.189-194
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• 2000

1) Crab shell의 납 흡착 실험결과 Langmuir 흡착 등온 모델에 잘 적용되었으며 $q_{max}$은 335.4 mg/g이었다. 2) 12시간 흡착 반응시킨 후 초기 농도에 대한 납 이온 제거효율을 고찰한 결과, 초기 납 이온 농도가 207.2 mg/l 이하에서는 97% 이상의 납 이온 제거 효율을 나타내었는데, 414.4 mg/l 이상에서는 제거효율이 60% 이하로 감소하였다. 3) 납 이온 흡착 전과 흡착 후의 crab shell을 전자현미경으로 분석한 결과 crab shell의 표면과 내부의 변화를 관찰할 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.285-285
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• 2013

수산화인회석(Hydroxyapatite, HAP)은 인체 내 뼈와 치아의 주성분으로서 칼슘과 인산염으로 구성된 물질이다. 암모늄을 이용하여 pH를 조절함으로서 hexagonal 형태의 HAP를 수열합성법으로 합성하였다. XRD pattern을 통하여 수산화인회석의 결정구조를 확인하였으며, 전이금속 중의 하나인 Fe(III) 이온을 이온교환반응을 통하여 수산화인회석 표면에 도입하였다. ICP 측정을 통해 Fe 함량을 정량하였고 SEM과 TEM image를 통하여 크기와 형태를 관찰하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.545-545
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• 2012

집속이온빔장치(FIB: Focused Ion Beam System)에 사용하는 액체금속이온원(LMIS: Liquid Metal Ion Source)은 고 전류밀도, 고 휘도, 낮은 에너지퍼짐 등 많은 장점이 있다. 집속이온빔장치는 주로 표면 분석, 집적 회로의 수정, 마스크 교정(Repair) 및 잘못된 부분의 분석(Failure Analysis) 등에 사용되고 있는데 최근에는 고 분해능의 이온빔 리소그래피와 이온 주입의 기술 및 미세가공 기술 등의 분야에 집중되고 있으며 이를 위해서는 집속이온빔장치의 수렴성(Convergence)을 개선해 나가는 것이 중요하다. 집속이온빔장치의 수렴성은 이온빔의 에너지 퍼짐(Energy Spread)과 각 분포(Angular Distribution)에 많은 영향을 받으며 에너지퍼짐 특성은 색수차에 직접적인 영향을 준다. 수렴성을 개선하기 위해 기존의 에미터(Emitter), 저장소(Reservoir), 추출극(Extractor)으로 제작된 액체금속이온원에 서프레서(Suppressor)라는 새로운 전극을 사용하여 이 전극의 유 무에 따른 각 분포의 변화에 대해 연구하였다.