• 한국표면공학회지
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• 제8권1호
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• pp.15-23
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• 1975

Electrodeposition of metals form aqueous solutions (eg, electroplating ) is frequently accompanied, by the discharge of hydrogen ions(in acidic solutions) or water molecules ( in alkaline electrolytes). The atomic hydrogen produced thus may partly diffuse into the interior of the substrate and when this is absorbed by iron/steel substrate, it has detrimental effects on the mechanical properties of the steel, leading to ahydrogen embrittlement. Steels, particularly the high strength steels, are prone to hydrogen embrittlement. In view of the increasing applications of high strength steels in variousindustries, particularly in the aircraft manufacture, there has been renewed interest in the studiesonhydrogen embrittlement during electroplating of metals. In this review, the author summarizes the reports on hydrogen embrittlement during preplating of metals. In this review , the author sumamrizes the hydrogen embrittlement during electroplating of metals. In this review , the author summarizes the reports on hydrogen embrittlement during preplating operations and electroplating of metals like copper, nickel, tin, zinc ,cadimum and chromium. Finally, the effect of degassing by baking to deembrittle the plated high tensile steels and mechanism of hydrogen embrittlement are briefly indicated.

• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.945-949
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• 1994

Mixtures of cyano complexes of palladium(II) and platinum(II) were separated by capillary electrophoresis using a fused silica capillary as a separation column and 30 mM phosphate buffer (pH 7) containing 15 wt. % acetonitrile as a running buffer. By virtue of the high ionic mobilities of the negatively charged cyano complexes of Pd(II) and Pt(II), they were separated using a cathodic injection and anodic detection scheme. The metal complexes eluted through the capillary were detected by direct UV absorption at 214 nm. A linear relationship between peak area and concentration was obtained for both ions and the detection limit was lower than $10^{-14}$ mole. The proposed method was applied to real sample, e.g., anode slime obtained from an electrolytic copper refinary, as a method for the simultaneous determination of palladium and platinum.

• Bulletin of the Korean Chemical Society
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• 제10권6호
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• pp.524-529
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• 1989

A glow discharge mass spectrometric(GDMS) analytical method was developed for direct analysis of impurities in solids. Ions extracted from a glow discharge ion source with a sample as a cathode were analyzed by a quadrupole mass filter. Ion extractions were carried out through differentially-pumped orifices biased to positive and negative potentials. Operating parameters of the glow discharge source such as discharge current, orifice-to-cathode distance, energy analyzer setting and bias voltages have been optimized. The developed GDMS was applied to the analysis of KSS copper-base alloy standards certified by Korea Standards Research Institute(KSRI). In the analysis, the reproducibility and the detection limits were estimated to be about 2.5% RSD, and in the low ppm range, respectively.

• Bulletin of the Korean Chemical Society
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• 제17권7호
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• pp.612-616
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• 1996

The new 1,2-dithiolene, 1,4-butanediyldithioethylene-1,2-dithiolate (BDDT2-), has been isolated. In addition, new monoanionic bis-complexes with nickel and copper have been prepared and characterized. In order to investigate the detailed electronic structure of the metal complexes of the new ligand, BDDT2-, in terms of the oxidation state of the central metal ions, we have carried out molecular orbital (MO) calculations of Ni(BDDT)2-and Cu(BDDT)2- utilizing an Extended Huckel method. Cyclic voltammetry data for both complexes were obtained with a potentiostat. We have also compared these results to the previously synthesized Ni(PDDT)2-, Ni(DDDT)2-,Cu(PDDT)2-, and Cu(DDDT)2-.

• Journal of Plant Biology
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• 제20권1호
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• pp.45-52
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• 1977

During the period of 1975-76, a survey was carried out to find out zinc indicators in the natural vegetation in Korea. The symptoms fo chlorosis were observed in flowering plants in the areas of zinc outcrop of Wolgok-A, Seokgok-9, and Sowolgok. Although 28 species were found to be chlorotic, the total quantity of chlorotic foliage observed was small. Reasons for chlorosis in the areas of zinc are deposits is considered as effects of zinc, lead, copper and calcium ions. Sedum sp. and Dianthus sinensis were confined to soil containing more than exchangeable zinc of 30 ppm and to accumulation in the plants contained at least 1,300-14,000 ppm of zinc. Therefore Sedum sp. and Dianthus sinensis might be used as zinc indicators in Korea.

• Bulletin of the Korean Chemical Society
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• 제12권2호
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• pp.219-224
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• 1991

New binuclear Ni(Ⅱ) and Cu(Ⅱ) complexes with various alkyl derivatives of 1,2-bis(1,3,6,8,10,13-hexaaza-1-cyclotetradecyl) ethane, in which two fully saturated 14-membered hexaaza macrocyclic subunits are linked together by an ethylene chain, have been synthesized by the one step template condensations of formaldehyde with ethylenediamine and appropriate primary alkyl amines in the presence of the metal ions. Each macrocyclic subunit of the double-ring macrocyclic complexes contains one alkyl pendant arm and has a square planar geometry with a 5-6-5-6 chelate ring sequence. The visible spectra and oxidation properties indicate that the metal-metal interaction of the binuclear complexes are not significant. Synthesis, characterization, and the properties of the complexes are presented.

• Molecules and Cells
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• 제20권3호
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• pp.401-408
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• 2005

Reactive oxygen species (ROS) contribute to the development of various human diseases. Cu,Zn-superoxide dismutase (SOD) is one of the major means by which cells counteract the deleterious effects of ROS. SOD activity is dependent upon bound copper ions supplied by its partner metallochaperone protein, copper chaperone for SOD (CCS). In the present study, we investigated the protective effects of PEP-1-CCS against neuronal cell death and ischemic insults. When PEP-1-CCS was added to the culture medium of neuronal cells, it rapidly entered the cells and protected them against paraquat-induced cell death. Moreover, transduced PEP-1-CCS markedly increased endogenous SOD activity in the cells. Immunohistochemical analysis revealed that it prevented neuronal cell death in the hippocampus in response to transient forebrain ischemia. These results suggest that CCS is essential to activate SOD, and that transduction of PEP-1-CCS provides a potential strategy for therapeutic delivery in various human diseases including stroke related to SOD or ROS.

• 한국방재안전학회논문집
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• 제14권1호
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• pp.23-40
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• 2021

세계적인 코로나19 대유행의 시대에, 현재 치료제·백신이 개발, 시판 중인 단계에서 병원내 교차감염의 위험성이 있는 상황이므로, 개인적으로는 후천적인 면역력을 제고하고 사회환경적으로 구리이온의 성능에 의한 생활방역체제를 일반화해야 한다. 감염확산방지를 위해 동서고금의 연구개발사례를 근거로 항균동 필름의 필요성 및 항바이러스 성능실험을 통해 효능성을 분석했다. 한국건설생활환경시험연구원(KCL)에서 항균성능인증 및 "국가승인 성능인증기관"에서 항바이러스 시험성적 인증을 받게 되었다. 당시 질병관리본부의 허가를 받은 실험재료인 NCCP 43326 Human corona virus(BetaCoV/Korea/KCDC03/2020)을 분양받아 생물안전기준에 맞게 생체외 실험실에서 In Vitro시험 결과, 항바이러스 성능시험에서 감염된 세포의 활성제거율이 만족할만한 결과를 도출하고 성능을 인증받게 되었다. 항후 코로나19 바이러스 확산방지대책으로 항바이러스 동필름이 시공된 유리창 공간내에서의 실험군과 항균동필름이 없는 동일조건의 대조군을 비교하는 질(質)적인 임상실험연구가 추가 필요하다.

• Applied Biological Chemistry
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• 제20권3호
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• pp.300-309
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• 1977

The information related to the heavy metal pollution in the environment was obtained from studies on the effects of pH, phosphate and soil properties on the adsorption of metal ions (Cd, Cu, Ni, and Zn) by soils. Three soil materials; soil 1 with low CEC (8.2 me/100g) and low organic carbon content (0.34%); soil 2 with high CEC (36.4 me/100g) and low organic carbon content (1.8%) and soil 3 with high CEC (49.9 me/100g) and high organic carbon content (14.7%) were used. Soils were adjusted to several pH's and equilibrated with metal ion mixtures of 4 different concentrations, each having equal equivalents of each metal ion (0.63, 1.88, 3.12 and 4.38 micromoles per one gram soil with and without 10 micromoles of phosphate per one gram soil). Reported here are the results of the equilibrium study on soil I. The rest of the results on soil 2 and soil 3 will be repoted subsequeutly. Generally higher metal ion concentration solution resulted in higher final metal ion concentrations in the equilibrated solution and phosphate had minimal effect except it tended to enhance removal of cadmium and zinc from equilibrated solutions while it tended to decrease the removal of copper and nickel. In soil 1, percentages of added metal ions removed at pH 5.10 were; Cu 97, Ni 69, Cd 63, and Zn 55, while increasing pH to 6.40, they were increased to Cu 90.9, Zn 99, Ni 96, and Cd 92 per As initial metal ion concentration increased, final metal ion concentrations in the equilibrated solution showed a relationship with pH of the system as they fit to the equation $p[M^{++}]=a$ pH+b where $p[M^{++}]=-log$[metal ion concentration in Mol/liter]. The magnitude of pH and soil effects were reflected in slope (a) of the equation, and were different among metal ions and soils. Slopes (a) for metal ions in the aqueous system are all 2. In soil 1 they were; Zn 1.23, Cu 0.99, Ni 0.69 and Cd 0.59 at highest concentration. The adsorption of Cd, Ni, and Zn in soil 1 could be represented by the Iangmuir isotherm. However, construction of the Iangmuir isotherm required the correction for pH differences.

• 대한화학회지
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• 제53권3호
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• pp.368-376
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• 2009

이 연구는 고등학교 화학I에서 이루어지는 금속의 반응성 실험에서 발견되는 문제점을 살펴보 고 이에 대한 이해를 목적으로 한다. 금속의 반응성 실험에서 제기된 문제는 세 가지로, 첫째 Al(s)이 전혀 반응하지 않는 이유와 반응을 관찰할 수 있는 방안, 둘째 Zn(s)과 FeS$O_4$(aq)의 반응에서 기포가 관찰 되는 이유, 셋째 FeS$O_4$(aq)와 Zn(s)의 반응에서 나타나는 침전의 정체 확인이다. 연구 결과 다음과 같은 결론을 내릴 수 있었다. 첫째, Al(s)은 산화피막 생성속도가 매우 빨라 반응을 관찰할 수 없으며, 강한 염산을 이용한 경쟁 반응을 이용하여 산화막 생성이 억제된 상태에서 알루미늄과 다른 금속 이온과의 반응을 관찰할 수 있다. 둘째, 발생하는 기포는 수소이온의 환원에 의한 수소기체로, 금속과 금속이온의 반응과 함께 물속의 수소이온이 특정한 농도범위에서 경쟁적으로 금속과 반응하고 있음을 확인하였다. 셋째, FeS$O_4$(aq)와 Zn(s)의 반응에서 Fe(s)은 관찰되지 않으며 Zn(s) 표면에 생성되는 검은색의 자성을 띠는 물질은 Fe3$O_4$(s)이고 용액 속에서 침전되는 적갈색의 고체는 $Fe_2O_3$(s)임을 광전자분광(X-Ray Photoelectron Spectroscopy) 분석으로 확인하였다.