• Corrosion Science and Technology
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• 제16권4호
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• pp.175-182
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• 2017

Galvanic current measurement, polarization curves, electrochemical impedance spectroscopy and weight loss test were used to study the corrosion behavior of carbon steel before and after carbon fibers coupling to the carbon steel in simulated concrete pore solutions, and the film composition on the steel surface was analyzed using XPS method. The results indicate that passive film on steel surface had excellent protective property in pore solutions with different pH values (13.3, 12.5 and 11.6). After coupling with carbon fibers (the area ratio of carbon steel to carbon fiber was 12.31), charge transfer resistance $R_{ct}$ of the steel surface decreased and the $Fe^{3+}/Fe^{2+}$ value in passive film decreased. As a result, stability of the film decreased and the corrosion rate of steel increased. Decreasing of the area ratio of steel to carbon fiber from 12.3 to 6.15 resulted in the decrease in $R_{ct}$ and the increase in corrosion rate. Especially in the pore solution with pH 11.6, the coupling leads the carbon steel to corrode easily.

• JSTS:Journal of Semiconductor Technology and Science
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• 제12권2호
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• pp.219-229
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• 2012

In the course of feasibility study the necessity of implementing electrochemical methods as an inline metrology technique to characterize semiconductor nano structures for a Deep Trench Dynamic Random Access Memory (DT-DRAM) (e.g. ultra shallow junctions USJ) was discussed. Hereby, the state of the art semiconductor technology on the advantages and disadvantages of the most recently used analytical techniques for characterization of nano electronic devices are mentioned. Various electrochemical methods, their measure relationship and correlations to physical quantities are explained. The most important issue of this paper is to prove the novel usefulness of the electrochemical micro cell in the semiconductor industry.

• 대한의용생체공학회:의공학회지
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• 제26권5호
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• pp.271-282
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• 2005

There are strong demands for accurate, fast, and inexpensive devices in the medical diagnostic laboratories, such as biosensors and chemical sensors. Biosensors can provide the reliable and accurate informations on the desired biochemical parameters, which is an essential prerequisite for a patient before going for a treatment. They can be used for continuous measurements of metabolites, blood cations, gases, etc. Of these, electrochemical biosensors play an important role in the improvement of public health, because rapid detection, high sensitivity, small size, and specificity are achievable for clinical diagnostics. In this paper, the clinical applications with electrochemical biosensors are reviewed. An attempt is also made to highlight some of the trends that govern the research and developments of the important biosensors that are associated to clinical diagnosis.

• 센서학회지
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• 제21권5호
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• pp.374-378
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• 2012

Biofouling causes many problem in industrial processes, medical health industries, water utilities and our daily life. So detecting formation of biofilm on the surface of medical appliance, water pipe and industrial utility is highly important to prevent the problem caused by biofouling. In this study, we suggest an electrochemical sensor for detecting biofilm. We fabricated the electrochemical sensor in MEMS process and cultivated two different kinds of Pseudomonas aeruginosa RpoN type and Wild type on the surface of electrochemical sensor. Each group of Pseudomonas aeruginosa was cultivated according to the hours of 2, 4, 6, 8, 12 and 24. Then we investigated changes in degree of biofilm cultivation using cyclic voltammetry. As a result, it was observed that peak of the cyclic voltammetry curve is increased according as the biofilm growth on the surface of electrochemical sensor. Also we can discern between Pseudomonas aeruginosa RpoN type and Wild type.

• 전기화학회지
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• 제14권1호
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• pp.22-26
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• 2011

Polypyrrole (Ppy) nanowire has been electrochemically synthesized via vertically oriented mesoporous silica template. The mesoporous template is also electrochemically deposited on indium tin oxide coated (ITO) glass from tetraethyl orthosilicate (TEOS) and cetyltrimethylammonium bromide (CTAB) surfactant. The highly ordered silica template is demonstrated to be 100~120nm thick with the pores of 4~5 nm diameter by scanning electron microscope (SEM) and transmission electron microscope (TEM). Ppy is formed to fill pores of the silica template from pyrrole solution by electrochemical oxidation. The Ppy in Ppy/silica/ITO composite was found to exhibit reversible electrochemical activity, as characterized by cyclic voltammetry (CV).

• Journal of Electrochemical Science and Technology
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• 제12권2호
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• pp.266-271
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• 2021

A commercial PbO₂ electrode was adopted as the anode for the electrochemical degradation of the real textile effluent with the initial COD of 56.0 mg L^-1 and the stainless steel plate as the cathode. The effect of the initial pH, the electrolyte flow rate and the cell voltage on the COD, the current efficiency and the energy consumption were investigated without the addition of NaCl or Na₂SO₄. The experimental results illustrated that the PbO₂ electrode can reduce the COD of the textile effluent from 56.0 mg L^-1 to 26.0 mg L^-1 with the current efficiency of 86.1% and the energy consumption of 17.5 kWh kg^-1 (per kilogram of degraded COD) under the optimal operating conditions. Therefore PbO₂ electrode as the anode was promising to further electrochemically degrade the real textile effluent.

• Journal of Electrochemical Science and Technology
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• 제13권1호
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• pp.148-158
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• 2022

The electrochemical CO₂ reduction (ECR) to produce value-added fuels and chemicals using clean energy sources (like solar and wind) is a promising technology to neutralize the carbon cycle and reproduce the fuels. Presently, the ECR has been the most attractive route to produce carbon-building blocks that have growing global production and high market demand. The electrochemical CO₂ reduction could be extensively implemented if it produces valuable products at those costs which are financially competitive with the present market prices. Herein, the electrochemical conversion of CO₂ obtained from flue gases of a power plant to produce diesel and formic acid using a consistent techno-economic approach is presented. The first scenario analyzed the production of diesel fuel which was formed through Fischer-Tropsch processing of CO (obtained through electroreduction of CO₂) and hydrogen, while in the second scenario, direct electrochemical CO₂ reduction to formic acid was considered. As per the base case assumptions extracted from the previous outstanding research studies, both processes weren't competitive with the existing fuel prices, indicating that high electrochemical (EC) cell capital cost was the main limiting component. The diesel fuel production was predicted as the best route for the cost-effective production of fuels under conceivable optimistic case assumptions, and the formic acid was found to be costly in terms of stored energy contents and has a facile production mechanism at those costs which are financially competitive with its bulk market price. In both processes, the liquid product cost was greatly affected by the parameters affecting the EC cell capital expenses, such as cost concerning the electrode area, faradaic efficiency, and current density.

• 전기화학회지
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• 제12권1호
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• pp.68-74
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• 2009

본 연구에서는 탄소성형 분리판의 물리화학적, 전기화학적 특성을 분석하여 수소 및 개미산연료 전지의 성능에 미치는 영향을 알아보았다. 기존 기계가공 탄소분리판과 탄소복합소재 탄소성형 분리판의 접촉저항, 부식특성, 소수성을 비교 평가하였다. 특히, 현재 연구개발 중인 탄소복합소재 성형분리판의 경우 계면접촉저항이 기계가공 분리판보다 1.5배 높게 나타났으며, 내식성 실험에서는 산에 취약하여 분리판 표면이 거칠어지고 결정성이 감소하였다. 연료전지의 성능은 분리판의 계면접촉저항에 크게 영향을 받았으며, 계면저항이 적은 기계가공 분리판이 수소 및 개미산 연료 전지에서 높은 성능을 나타냈다.

• 한국생산제조학회지
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• 제22권5호
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• pp.795-799
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• 2013

This paper describes a novel hybrid surface polishing process combining non-traditional electrochemical polishing (ECP) with external artificial ultrasonic vibration. The purpose of this study is to develop an easier method for improving stainless steel surfaces. To this end, vibration electrochemical polishing (VECP), a novel ultrasonic manufacturing process, for enhancing electrochemical reaction and surface quality compared with that achieved using conventional ECP is suggested. In addition, for finding the optimized experimental conditions, the two methods are compared under various current densities. Localized roughness of the work material is measured with atomic force microscopy (AFM) and scanning electron microscopy (SEM) for obtaining detailed surface information.

• 전기화학회지
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• 제3권2호
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• pp.76-80
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• 2000

Electrochemical oxidation of ethanol has been studied at nickel and $RuO_2-modified$ nickel electrodes in 1 M KOH using electrochemical impedance spectroscopy. Equivalent circuits have been worked out from simulation of impedance data to model oxidation of ethanol as well as the passivation of the electrode. The charge-transfer resistances for oxidation of these electrodes became smaller in the presence of ethanol than in its absence. The nickel substrate facilitated ethanol oxidation at $RuO_2-modified$ nickel electrodes. We also describe the Performance of nanosized electrocatalysts of the same composition in comparison to those of the bulk electrodes. The nanosized electrodes were obtained by electrode-positing the alloy from complexed form of these metal ions with fourth and fifth generation polyamidoamine dendrimers.