• 제목/요약/키워드: Cathodic

검색결과 755건 처리시간 0.043초

A Kinetic Investigation of Ethanol Oxidation on a Nickel Oxyhydroxide Electrode

  • Danaee, I.;Jafarian, M.;Sharafi, M.;Gobal, F.
    • Journal of Electrochemical Science and Technology
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    • 제3권1호
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    • pp.50-56
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    • 2012
  • Nickel modified NiOOH electrodes were used for the electrocatalytic oxidation of ethanol in alkaline solutions where the methods of cyclic voltammetry (CV) and chronoamperometry (CA) were employed. In CV studies, in the presence of ethanol, an increase in the current for the oxidation of nickel hydroxide is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of ethanol is being catalysed through mediated electron transfer across the nickel hydroxide layer comprising of nickel ions of various valence states. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of ethanol was found to be $1{\times}10^7cm^2s^{-1}$.

Study on Electrochemical Properties of TBT(Tributyltin)

  • Park, Chil-Nam;Yang, Hyo-Kyung
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제10권S_4호
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    • pp.173-179
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    • 2001
  • The chemical behavior and properties of the redox state of environmental pollutants was investigated using electrochemical methods. The purpose was to measure the variations in the redox reaction of differential pulse polarograms and cyclic voltammograms. The results observed the influences on redox potential and current of various factors including concentration, temperature, salt, and pH. These were established factors as the effect of the redox reaction. It can be clearly recognized that the electrode reaction are from reversible to irreversible processes. Also, it was mixing with reaction current controlled.

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Corrosion Characteristics with Polarization Curve of Polymers

  • Park, Chil-Nam;Jung, Oh-Jin
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제10권S_4호
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    • pp.181-187
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    • 2001
  • This study was carried out to measure the variations of potential and current density with polymers. The results were particularly examined to identify the influences on potential and rate of various factors including temperature and pH. The Tafel slope for anodic dissolution was determined by the polarization effect depending on these conditions. The optimum conditions were established for each case. The second anodic current density peak and maximum current density were designated as the relative polarization sensitivity$(I_r/I_f)$. The mass transfer coefficient value$(\alpha)$ was determined with the Tafel slope for anodic dissolution based on the polarization effect with optimum conditions.

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가정용 연료전지 시스템의 전기 효율 향상을 위한 연료/공기 이용률 운전 최적화 (Operational Optimization of Anodic/cathodic Utilization for a Residential Power Generation System to Improve System Power Efficiency)

  • 석동훈;김민진;손영준;이진호
    • 한국수소및신에너지학회논문집
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    • 제24권5호
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    • pp.373-385
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    • 2013
  • To obtain higher power efficiency of Residential Power Generation system(RPG), it is needed to operate system on optimized stoichiometric ratios of fuel and air. Stoichiometric ratios of fuel/air are closely related to efficiency of stack, reformer and power consumption of Balance Of Plant(BOP). In this paper, optimizing stoichiometric ratios of fuel/air are conducted through systematic experiments and modeling. Based on fundamental principles and experimental data, constraints are chosen. By implementing these optimum values of stoichiometric ratios, power efficiency of the system could be maximized.

다이어몬드상 탄소/실리콘 이종접합 태양전지의 특성 및 신뢰성 분석에 관한 연구 (A study on the characterization of properties and stabilities of a solar cell using diamond-like carbon/silicon heterojunctions)

  • 박진석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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    • pp.683-687
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    • 1997
  • The purpose of this work is to develop a highly reliable solar cell based on the diamond-like carbon(DLC)/silicon heterojunction. Thin films of DLC have been deposited by employing both filtered cathodic vacuum arc(FCVA) and magnetron plasma-enhanced chemical vapor deposition(m-PECVD) systems. Structural, electrical, and optical properties of DLC films deposited are systematically analyzed as a function of deposition conditions, such as magnetic field, substrate bias voltage, gas pressure, and nitrogen content. The I-V measurement has been used to elucidate the mechanism responsible for the conduction process in the DLC/Si junction. Photoresponse characteristics of the junction are measured and its reliability against temperature and light stresses is also analyzed.

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선체 부식에 의한 수중 전기장 신호 특성 모델링 기법 연구 (A Study on the Modelling Method of Underwater Electric Field Signature due to Ship's Corrosion)

  • 정현주;양창섭;전재진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.876-878
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    • 2008
  • The galvanic corrosion of a vessel, or systems fitted to minimize the ship's corrosion such as ICCP(Impressed Current Cathodic Protection) system and sacrificial anodes, can lead to significant electrical current flow in the sea. The presence of vessel's current sources associated with corrosion will give rise to detectable electric field surrounding the vessel and can put it at risk from mine threats. For this reason, it is necessary to design corrosion protection systems so that they don't only prevent a hull corrosion but also minimize the electric field signature. In this paper, we describe theoretical backgrounds of underwater electric field signature due to corrosion and corrosion protection system on naval vessels and analysis results of the electric field according to ICCP anode arrangement.

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Synthesis and Characterization of New Nickel Sulfide Precursor

  • Lee, Sang Chan;Park, Bo Keun;Chung, Taek-Mo;Hong, Chang Seop;Kim, Chang Gyoun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.365.2-365.2
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    • 2014
  • Nickel sulfide (NiS) has been utilized in optoelectronic applications, such as transformation-toughening agent for materials used in semiconductor applications, catalysts, and cathodic materials in rechargeable lithium batteries. Recently, high quality nickel sulfide thin films have been explored using ALD/CVD technique. Suitable precursors are needed to deposit thin films of inorganic materials. However, nickel sulfide precursors available for ALD/CVD process are very limited to nickel complexes with dithiocarbamate and alkanethiolate ligands. Therefore, it is essential to prepare novel nickel sulfide suitable for ALD/CVD precesses. Herein we report on the synthesis and characterization of new nickel sulfide complex with designed aminothiolate ligand. Furthermore thin films of NiS have been prepared on silicon oxide substrates by spin coating nickel precursor 10 wt% in THF. The novel complex has been characterized by means of 1H-NMR, elemental analysis, thermogravimetric analysis (TGA), X-ray Diffraction (XRD) and scanning electron microscope (SEM).

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과천지역의 상세 토양비저항도(1/5000) 작성 (Development of Detailed Soil Resistivity Map(1/5000) in Kwachon)

  • 이현구;김대경;배정효;하태현;정성환;최상봉
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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    • pp.315-317
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    • 1999
  • Soil resistivity has a relation with the corrosion of underground buried structures as a water pipeline, gas pipeline and power cable casing. And it's a main factor in the cathodic protection and earth design. This paper presents soil resistivity maps each depth through measuring the soil resistivity in Kwachon, Kyonggi province. Also examines the soil resistivity characteristics on a change of temperature, moisture content and ion content in the laboratory.

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FORMATION OF AMORPHOUS NICKEL-PHOSPHORUS ALLOY FILM

  • Yamashita, Tsugito;Komiyama, Toyohiko
    • 한국표면공학회지
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    • 제29권6호
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    • pp.720-723
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    • 1996
  • The behavior of electrodeposition of amorphous nickel-phosphorus has been studied from the point of deposition mechanism, kinetic parameters, morphology and formation of alloy films. The electorode reaction and electrode kinetics of deposition of nickel were significantly influenced by the content of phosphorus. The cathodic deposition of nickel-phosphorus alloy might be governed by the diffusion process of phosphorous acid. The direction of growth layer of the nickel-phosphorus alloy was different with substrate material. The formation of nickel-phosphorus alloy films was affected considerably by the solution compositions, electrolytic conditions and properties of the material as an underlayer.

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황산크륨(III) 착화합물 스용액으로부터의 크롬전착반응의 전기화학적 거동 (Electrochemical Behaviors of Chromium Electrodeposition from Chromium(III) Sulfate complexes Aqueous Solutions)

  • 고석수;송진태
    • 한국표면공학회지
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    • 제21권4호
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    • pp.160-167
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    • 1988
  • Electrochemical behaviors od chromium electrodeposition from 0.05M chromium (III) sulface complexes in aqueous solutions using sodium formate-glycine mixtures as a complexing agent were studied. In the cathodic current-potential cures, it is found that the intial limiting current of Cr(III) is proportional to square root of scan rate and activiation energy from Arrhenius plot is s obtained 3.05Kcal/mol. From this results, the reaction is considered, Cr3++e longrightarrow Cr2+, which is controlled diffusion of Cr (III). It is also found that the chromium is deposited when the potential reaches to hydrogen evolution potential. Effects of NaSCN as a catalyser in the electrolyte were investigated NCS- anion seems to react strongly by specific absorption at the inner HelmholtZ layer, so that, it is considered to suppress the electrodeposition reaction reaction for chromjum, and also it is considered multipe-bridge such as Cr(III)-NCS---M(M;cathode).

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