• 제목/요약/키워드: Electrochemical methods

검색결과 571건 처리시간 0.031초

Investigation on Trend Removal in Time Domain Analysis of Electrochemical Noise Data Using Polynomial Fitting and Moving Average Removal Methods

  • Havashinejadian, E.;Danaee, I.;Eskandari, H.;Nikmanesh, S.
    • Journal of Electrochemical Science and Technology
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    • 제8권2호
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    • pp.115-123
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    • 2017
  • Electrochemical noise signals in many cases exhibit a DC drift that should be removed prior to further data analysis. Polynomial fitting and moving average removal method have been used to remove trends of electrochemical noise (EN) in time domain. The corrosion inhibition of synthesized schiff base N,N'-bis(3,5-dihydroxyacetophenone)-2,2-dimethylpropandiimine on API-5L-X70 steel in hydrochloric acid solutions were used to study the effects of drifts removal methods on noise resistance calculation. Also, electrochemical impedance spectroscopy (EIS) was used to study the corrosion inhibition property of the inhibitor. The results showed that for the calculation of $R_n$, both methods were effective in trend removal and the polynomial with m=4 and MAR with p=40 were in agreement.

The Fundamentals of Reduction of UO22+ Ions on a Pt Electrode and Methods for Improving Reduction Current Efficiency

  • Yeon, Jei-Won;Pyun, Su-Il
    • 전기화학회지
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    • 제10권2호
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    • pp.73-81
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    • 2007
  • This review article considered the electrochemical reduction of uranyl ions on a Pt surface. Specifically, we focussed on the improvement in its reduction current efficiency. First, this article briefly explained the fundamentals of the reduction of uranyl ($UO_2^{2+}$) ions on a Pt surface. Namely, they involved the electrochemical behaviour of uranium species, and electrochemical cell configurations for the reduction of $UO_2^{2+}$ ions. In addition, the effects of adsorbed hydrogen atoms were investigated on the reduction of $UO_2^{2+}$ ions. Finally, this article presented the methods for improving current efficiency of the reduction of $UO_2^{2+}$ ions on a Pt surface. Three different kinds of methods are introduced, which include electrochemical surface treatments of Pt electrode involving hydrogenation and anodisation, the use of catalyst poisons, and formation of thin mercury film on a Pt electrode. Moreover, this article provided some clues about how hydrogenation and catalyst poisons work on the reduction of $UO_2^{2+}$ ions.

Implementation of Electrochemical Methods for Metrology and Analysis of Nano Electronic Structures of Deep Trench DRAM

  • Zeru, Tadios Tesfu;Schroth, Stephan;Kuecher, Peter
    • 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.

전기화학 가공을 이용한 마이크로 홈 가공 (Micro Groove Machining for Electrochemical Micro-Machining)

  • 김영민;이은상
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1844-1847
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    • 2003
  • Electrochemical micro-machining(EMM) is used to achieve a desired workpiece surface by dissolving the metal workpiece with an electrochemical reaction. This machining method can be applied to metal that is difficult to machining using other methods. The workpiece dissolves when it is positioned close to the tool electrode in electrolyte and current is applied. This aim of this work is to develop electrochemical micro-machining(EMM) technique for micro groove shape by establishing appropriate electrochemical parameters of machining

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전기화학적 방법에 의한 AISI 304 스테인리스강 용접부의 내식성 평가 (A Corrosion Resistance Evaluation of Welded AISI 304 Stainless Steel by Electrochemical Methods.)

  • 백신영;김관휴
    • Journal of Advanced Marine Engineering and Technology
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    • 제14권1호
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    • pp.83-89
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    • 1990
  • Electrochemical methods have been proposed as non-destructive, rapid and quantitative means for determining the degree of sensitization associated with Chromium depleted zones surrounding precipitates of Cr carbide and formation of secondary phase in stainless steel. In this study, the specimen of AISI 304 stainless steel and its welded sections, which welded by TIG, MIG, $CO_2$ and ARC, were tested corrosion resistance by electrochemical methods in 0.5N HCl and 1N $H_2SO_4$ with or without 0.01N KSCN. The results were confirmed that electrochemical methods could be used as a test method of corrosion resistance evaluation for the welded AISI 304 stainless steel.

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Probing of Electrochemical Reactions for Battery Applications by Atomic Force Microscopy

  • 김윤석
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.98.2-98.2
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    • 2013
  • Electrochemical phenomena underpin a broad spectrum of energy, chemical, and information technologies such as resistive memories and secondary batteries. The optimization of functionalities in these devices requires understanding electrochemical mechanisms on the nanoscale. Even though the nanoscale electrochemical phenomena have been studied by electron microscopies, these methods are limited for analyzing dynamic electrochemical behavior and there is still lack of information on the nanoscale electrochemical mechanisms. The alternative way can be an atomic force microscopy (AFM) because AFM allows nanoscale measurements and, furthermore, electrochemical reaction can be controlled by an application of electric field through AFM tip. Here, I will summarize recent studies to probe nanoscale electrochemical reaction in battery applications by AFM. In particular, we have recently developed electromechanical based AFM techniques for exploring reversible and irreversible electrochemical phenomena on the nanoscale. The present work suggests new strategies to explore fundamental electrochemical mechanisms using the AFM approach and eventually will provide a powerful paradigm for probing spatially resolved electrochemical information for energy applications.

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비금속 자원 재활용을 위한 전해부상 장치를 이용한 고농도 유기질 폐수의 재활용에 관한 연구 (A Study on Recycle of Concreted Organic Waste water by Electroflotation Apparatus for Resource Recycle of Non-Metal)

  • 김기준;남상성
    • 한국응용과학기술학회지
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    • 제29권4호
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    • pp.653-658
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    • 2012
  • 고농도 유기질 폐수처리를 위해 전기화학적 방법의 사용에 있어 관심이 고조되고 있다. 전기화학적 방법의 기술은 음식물폐수 및 공업적 폐수 문제를 해결하는데 이상적 처리 방법이다. 다른 화학적 처리 방법과는 다르게 전기화학적 처리장치는 2차 폐수의 부피를 증가시키지 않고 용수와 유기질 비료로 재활용한다. 전기화학적 방법은 전해부상장치를 무기화학적 약품과 병행하여 더욱 효과적으로 음식물 폐수를 처리한다. 이 연구는 2차 처리로 초음파와 오존처리로 탈색, COD와 BOD가 격감함으로 용수 및 유기질 비료로 활용하도록 실험하였다.

Conversion of a Constant Phase Element to an Equivalent Capacitor

  • Chang, Byoung-Yong
    • Journal of Electrochemical Science and Technology
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    • 제11권3호
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    • pp.318-321
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    • 2020
  • Here I present a formula which converts a constant phase element (CPE) to its equivalent capacitor. Electrochemical impedance spectroscopy is capable of resolving a complex electrochemical processes into its faradaic and non-faradaic elements, and the non-faradaic process is frequently described as a CPE in place of a capacitor due to the non-ideality. Being described as a capacitor, the non-faradaic element provides information by its capacitance, but a CPE cannot provide a physical meaning. In order to solve the problem, the CPE has been dealt with as an equivalent capacitor of which the capacitance provides practical information. Succeeding the two methods previously suggested, a new conversion method is suggested in this report. While the previous ones manipulate only the CPE, the new method takes both the CPE and its related resistor into account for conversion. By comparing the results obtained by the three methods, we learn that the results are nearly the same within tolerable ranges, and conclude that any of the method choices is acceptable depending on the conditions of the system of interest.

전기화학적 수소 압축기 기술 (A Review of Electrochemical Hydrogen Compressor Technology)

  • 김상경
    • 한국수소및신에너지학회논문집
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    • 제31권6호
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    • pp.578-586
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    • 2020
  • There is growing interest worldwide in a hydrogen economy that uses hydrogen as an energy medium instead of hydrocarbon-based fossil fuels as a way to combat climate change. Since hydrogen has a very low energy density per unit volume at room temperature, hydrogen must be compressed and stored in order to use as an energy carrier. There are mechanical and non-mechanical methods for compressing hydrogen. The mechanical method has disadvantages such as high energy consumption, durability problems of moving parts, hydrogen contamination by lubricants, and noise. Among the non-mechanical compression methods, electrochemical compression consumes less energy and can compress hydrogen with high purity. In this paper, research trends are reviewed, focusing on research papers on electrochemical hydrogen compression technology, and future research directions are suggested.

미세 전해가공 기술 동향 (Review of Micro Electro-Chemical Machining)

  • 신홍식
    • 융복합기술연구소 논문집
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    • 제2권2호
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    • pp.25-29
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    • 2012
  • Micro machining technologies have been required to satisfy various conditions in a high-technology industry. Micro electrochemical process is one of the most precision machining methods. Micro electrochemical process has been divided into electrochemical etching through protective layer and electrochemical machining using ultrashort voltage pulses. Micro shaft can be fabricated by electrochemical etching. The various protective layers such as photo-resist, oxide layer and oxidized recast layer have been used to protect metal surface during electrochemical etching. Micro patterning on metal surface can be machined by electrochemical etching through protective layer. Micro hole, groove and structures can be easily machined by electrochemical machining using ultrashort voltage pulses. Recently, the groove with subnanometer was machined using AFM.

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