Electrochemistry
Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Volume 80 , Issue 4
Showing 1-18 articles out of 18 articles from the selected issue
Preface
Communications
  • HARIYANTI, Gamal. A. EL-MAHDY, Atsushi NISHIKATA, Tooru TSURU
    2012 Volume 80 Issue 4 Pages 214-217
    Published: April 05, 2012
    Released: April 05, 2012
    JOURNALS OPEN ACCESS
    Effect of scratching of coating surface on the electrochemical behavior of PVD Al-Mg-Si coated steel has been investigated using an open circuit potential (OCP), anodic polarization and galvanic couple test. The OCP monitoring showed a fast ennoblement of OCP then attained a steady state value during the last stage of monitoring. There were two types of corrosion products of scratched coating that protected from continuous corrosion and act as self-healing. The first is passive film that arises from the adjacent coating surface on both sides of scratched area and covering the underlying steel. The second is corrosion product produced by the corrosion of steel on scratched area.
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  • HARIYANTI, Amar P. YADAV, Atsushi NISHIKATA, Tooru TSURU
    2012 Volume 80 Issue 4 Pages 218-221
    Published: April 05, 2012
    Released: April 05, 2012
    JOURNALS OPEN ACCESS
    The corrosion products formed on Zn, Zn-55Al and Al-8.2Mg-4.8Si alloys coating has been investigated by potentiodynamic polarization in a mixture of 0.5 M Na2SO4 and 0.1 M NaCl solution. The anodic current density on Zn and Zn-55Al alloys coating show the existence of dissolution indicated that Zn and Zn-55Al alloy continued to dissolve across the corrosion product formed. The existence of corrosion product on Al-8.2Mg-4.8Si alloys coating shifted the polarization curves to more noble direction and inhibit the dissolution.
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  • Masahiro KUNIMOTO, Kenji SEKI, Hiromi NAKAI, Takayuki HOMMA
    2012 Volume 80 Issue 4 Pages 222-225
    Published: April 05, 2012
    Released: April 05, 2012
    JOURNALS OPEN ACCESS
    The influence of water molecules on the reaction behavior of hypophosphite ion, which acts as a reducing agent for electroless deposition, on metal surfaces was elucidated by calculating the adsorption structure of hydrated hypophosphite ion on a Pd surface using Monte-Carlo simulation and density functional theory calculations. Through geometrical optimization, the most favorable structure of the hydrated hypophosphite ion was obtained, in which six water molecules interact with the oxygen of hypophosphite ion and no water interacts with the hydrogen of hypophosphite ion. Further calculations indicated that the hydrated hypophosphite ion adsorbed on the Pd surface via hydrogen.
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Articles
  • H. H. ABDEL-RAHMAN, A. A. HARFOUSH, A. H. E. MOUSTAFA
    2012 Volume 80 Issue 4 Pages 226-238
    Published: April 05, 2012
    Released: April 05, 2012
    JOURNALS OPEN ACCESS
    Effect of amines as organic additives on copper electrodeposition from acidic sulphate solutions were investigated by different electrochemical methods [potentio-dynamic method, rotating cylinder electrode (RCE) and rotating disk electrode (RDE)] as well as by observation technique [scanning electron microscopy (SEM)] which reveal that the surface morphology was affected by the nature of the organic additives to a large extent. This means that the shape of dendrites depends on the composition of plating solution. The correlation between % inhibition and the molecular structure of amines as group of nitrogen containing organic compounds has been extensively investigated. Different models of adsorption isotherm, thermodynamic parameters, and dimensionless group correlation have been studied to understand the effect of such amines on the electrodeposition process.
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Technological Report
  • Akihiko NOIE, Hidekazu FUJIMURA, Shin TAKAHASHI, Nariyoshi KOBAYASHI, ...
    2012 Volume 80 Issue 4 Pages 239-245
    Published: April 05, 2012
    Released: April 05, 2012
    JOURNALS OPEN ACCESS
    For practical use of the Solid Oxide Fuel Cell (SOFC) cogeneration system, we suggested the direct heating method of SOFC module which could balance the cell performance and the soundness of the cell. From heat flux motion analysis of the equivalence ratio distribution on the burner, the best possible burner for direct heating was assumed to be the surface combustion burner which had many cluster nozzles in order to prevent the back fire and a rectification plate in an air header. The distribution of equivalent ratio φ at the non-combustion of the surface combustion anode burner was 1.09 ≦ φ ≦ 1.25. The residual oxygen concentration in combustion gases was less than 100 ppm, and the soot did not occur. The mean open circuit voltage of the bundle of the 10kW class SOFC module was 5.45V within ±0.7% precision, when the mean central temperature of the bundle was 665.5°C. The difference of the cell temperatures in the axial direction was controlled at less than 66°C and the difference between the temperatures inside and outside of the cells was controlled at less than 4°C. As a result a cell was able to reduce thermal stress and to maintain soundness. We demonstrated the validity of the direct heating method of SOFC module with the combustion gases of the burner.
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