• 한국염색가공학회지
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• 제25권1호
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• pp.1-6
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• 2013

Nowdays, the computational simulation of molecular energy potentials and the empirical evidence using electrochemical reduction/oxidation values are very significant factors to predict of molecule's energy potentials. The prepared chemosensor herein consists of spirolactam ring system in the structure, providing intra-structural change with metal cation binding. In this study, rhodamine 6G-Naphthaldehyde chemosensor was determined and compared with HOMO/LUMO energy levels by computational calculation and cyclic voltammogram method.

• Nuclear Engineering and Technology
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• 제32권6호
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• pp.595-604
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• 2000

Flow-Accelerated Corrosion Behavior of SA106 Gr.C steel in room temperature alkaline solution simulating the CANDU primary water condition was studied using Rotating Cylinder Electrode. Systems of RCE were set up and electrochemical parameters were applied at various rotating speeds. Corrosion current density decreased up to pH 10.4 then it increased rapidly at higher pH. This is due to the increasing tendency of cathodic and anodic exchange half-cell current. Corrosion potential shifted slightly upward with rotating velocity. Passive film was formed from pH 9.8 by the mechanism of step oxidation and the subsequent precipitation of ferrous species into hydroxyl compound. Above pH 10.4, the film formation process was active and the film became stable. Corrosion current density showed increment in pH 6.98 with the rotating velocity, while it soon saturated from 1000 rpm above pH 9.8. This seems that activation process which represents formation of passive film on the bare metal surface controls the entire corrosion process

• 자원리싸이클링
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• 제26권4호
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• pp.34-41
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• 2017

황산용액에 함유된 망간(II)의 농도가 Pb-Ag양극의 산화거동에 미치는 영향을 1.8에서 2.0 V의 범위에서 정전위법으로 조사하였다. 산화전위가 높고 망간의 초기 농도가 낮은 조건에서는 망간(III)의 농도가 높았으며, 산화반응 후 용액을 분광학적으로 분석하여 이를 확인하였다. 1.8과 1.9 V에서는 $MnO_2$가 망간(II)의 산화에 의해 생성되나, 2.0 V에서는 망간(III)의 불균등화반응에 의해 형성되었다. 1.8 V에서 용액에 망간(II)이 존재하면 정전위조건에서 산화시킬 때 납이 $PbO_2$로 산화되지 않았다. 그러나 1.9와 2.0 V에서는 망간(II)농도가 증가함에 따라 $PbO_2$가 망간(II)에 의해 화학적으로 환원되어 $PbO_2$의 양이 감소하였다.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1669-1678
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• 2011

Six new binuclear copper(II) complexes have been prepared by template condensation of the dialdehydes 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-a) and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-l,4,8,11-tetraazacyclotetradecane (PC-b) with appropriate aliphatic diamines, and copper(II) perchlorate. The structural features of the complexes have been confirmed by elemental analysis, IR, UV-vis and mass spectra etc. The electrochemical behavior of all the copper(II) complexes show two irreversible one electron reduction process. The room temperature magnetic moment studies depict the presence of an antiferromagnetic interaction in the binuclear complexes. The catechol oxidation and hydrolysis of 4-nitrophenylphosphate were carried out by using the complexes as catalyst. The antimicrobial screening data show good results. The binding of the complexes to calf thymus DNA (CT DNA) has been investigated with absorption and emission spectroscopy. The complex [$Cu_2L^{1a}$] displays significant cleavage property of circular plasmid pBR322 DNA in to linear form. Spectral, electrochemical, magnetic and catalytic studies support the distortion of the copper ion geometry that arises as the macrocyclic ring size increases.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.251-251
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• 2016

For several decades, industrial processes consume a huge amount of raw water for various objects that consequently results in the generation of large amounts of wastewater. Wastewaters are consisting of complex mixture of different inorganic and organic compounds and some of them can be toxic, hazardous and hard to degrade. These effluents are mainly treated by conventional technologies such are aerobic and anaerobic treatment and chemical coagulation. But, these processes are not suitable for eliminating all hazardous chemical compounds form wastewater and generate a large amount of toxic sludge. Therefore, other processes have been studied and applied together with these techniques to enhance purification results. These include photocatalysis, absorption, advanced oxidation processes, and ozonation, but also have their own drawbacks. In recent years, electrochemical techniques have received attention as wastewater treatment process that could be show higher purification results. Among them, boron doped diamond (BDD) attract attention as electrochemical electrode due to good chemical and electrochemical stability, long lifetime and wide potential window that necessary properties for anode electrode. So, there are many researches about high quality BDD on Nb, Ta, W and Si substrates, but, their application in effluents treatment is not suitable due to high cost of metal and low conductivity of Si. To solve these problems, Ti has been candidate as substrate in consideration of cost and property. But there are adhesion issues that must be overcome to apply Ti as BDD substrate. Al, Cu, Ti and Nb thin films were deposited on Ti substrate to improve adhesion between substrate and BDD thin film. In this paper, BDD films were deposited by hot filament chemical vapor deposition (HF-CVD) method. Prior to deposition, cleaning processes were conducted in acetone, ethanol, and isopropyl alcohol (IPA) using sonification machine for 7 min, respectively. And metal layer with the thickness of 200 nm were deposited by DC magnetron sputtering (DCMS). To analyze microstructure X-ray diffraction (XRD, Bruker gads) and field emission scanning electron microscopy (FE-SEM, Hitachi) were used. It is confirmed that metal layer was effective to adhesion property and improved electrode property. Electrochemical measurements were carried out in a three electrode electrochemical cell containing a 0.5 % H2SO4 in deionized water. As a result, it is confirmed that metal inter layer heavily effect on BDD property by improving adhesion property due to suppressing formation of titanium carbide.

• 폴리머
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• 제25권4호
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• pp.568-574
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• 2001

Bisphenol A ethoxylate diacrylate를 가교제로 사용하여 PEO계 고분자 고체전해질을 제조하였으며, 이의 전기화학적 특성 및 기계적인 물성을 조사하였다. 제조된 고분자 고체전해질은 이온전도도를 높이기 위해 비휘발성의 PEGDMe [poly(ethylene glycol) dimethyl ether]를 가소제로 도입하였다. 첨가된 PEGDMe 함량이 높을수록 전기전도도는 증가하였다. 최대 이온전도도는 30에서 1.0 ${\times}$ 10$^{-3}$S/cm [Bisphenol A ethoxylate diacrylate ([EO]/[phenol]=15), PEGDMe250 80 wt%, LiCF$_3SO_3$]이었다. 제조된 고분자 전해질의 인장강도는 0.4 ~ 5 MPa이었으며 ${\phi}$=3 mm 봉에 대해 90$^{\circ}$ 및 180$^{\circ}$ 의 굽힘에도 균열을 발생하지 않았다. 리튬 기준전극에 대해 4.5 V 이상의 산화전위에도 전기화학적으로 안정하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1100-1103
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• 2003

One of the good ways to raise the rate of the electrochemical reaction is to broaden the effective surface area of the electrode by developing cylindrical nano-pores on the surfaces. The numerous pores of several nanometer in diameter can be used to enhance a specific faradaic reaction so that the nano-porous structure attract keen attention in terms of implication of new bio/chemical sensors, in which no chemical modification is involved. Amperometric glucose sensor is a representative example that needs the selective enhancement of glucose oxidation over the current due to physiological interferents such as ascorbic acid. The present paper reports how the ascorbic acid and glucose diffuse around the nano-porous surface by simulation study, for which 2D-FDM (Finite Difference Method) was adopted. The results of the simulation not only consist with those from electrochemical experiments but also reveal valuable potential for more advanced application of the nano-porous electrode.

• 전기화학회지
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• 제17권1호
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• pp.30-36
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• 2014

산화/환원 매개체는 혈당 센서의 구성에서 전극과 효소 반응의 전자 전달 매개체로서 중요한 역할을 담당한다. 본 연구에서는 기존의 산화/환원 매개체보다 전자 전달 반응이 용이하며, 높은 민감도를 위해 페레이트에 아닐린을 결합시켜, 1차 아민기를 갖는 $Fe(CN)_5$-aminopyridine를 합성하였다. 합성된 $Fe(CN)_5$-aminopyridine 는 순환 전압 전류 법과 분광학적 방법을 이용하여 합성 결과를 확인하였다. 합성된 물질과 포도당을 측정하기 위한 당 탈 수소 효소를 ITO 전극위에 고정시켜 효소전극을 제작하였고, 또한 신호 증폭을 위하여 금 나노 입자를 함께 고정시켰다. 금 나노 입자가 고정된 효소 전극은 그렇지 않은 전극에 비해 약 2배 가량의 전류 밀도가 증가함을 확인하였다. 만들어진 효소 전극에서 포도당의 농도 별 산화 촉매 전류를 순환 전압 전류 법으로 측정한 결과 0.4 V (vs. Ag/AgCl)에서 전기적 신호가 발생되었으며, 포도당 0~10 mM의 농도 범위에서 전기적 신호가 선형 증가함을 확인할 수 있었다.

• 환경위생공학
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• 제20권1호
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• pp.32-39
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• 2005

Recently, sanitary landfill was one of the most widely used for disposal of waste in Korea. With increasing of use and public awareness of this method for disposal. there is an increased concern with respect to the pollution potential by the landfill leachate. Especially, an aged landfill leachate contained relatively large amount of the nonbiodegradable substances which could not be removed by biological treatment processes. So, this study was conducted to the removal of nonbiodegradable substances, such as Humic acid and Fulvic acid with the electrolysis. In this study, electrode materials, electrolyte concentration, electrode distance, current density, and pH value were found to have significant effect on both pollutant removal efficiency and current efficiency in electrochemical oxidation process.

• Journal of Advanced Marine Engineering and Technology
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• 제36권3호
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• pp.341-350
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• 2012

In this paper we observe the protective coatings carbon for steel, aluminium and titanium alloys were obtained by plasma electrolytic oxidation (PEO) under unipolar and bipolar conditions. The anticorrosion properties and the thermal stability of the surface layers were studied by electrochemical impedance spectroscopy and potentiodynamic polarization. It was found that the application of the bipolar PEO mode enables one to synthesize the surface layers that possess enhanced anticorrosion and mechanical properties. results of research of antiscale PEO - coatings for marine power equipment are presented. The combined method of prevention of corrosion and scale formation was tested at the industrial plants of Russian Shipyard "Zvezda".