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Showing 1 to 20 of 56 for “"Tafel"”.
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Die NutzerInnen der Oldenburger Tafel - Lebensstandard, Deprivation und Kohäsion einer Subgruppe von Armut betroffener Menschen
… der noch relativ jungen interdisziplinären Tafelforschung und erweitert den bisherigen Diskurs, indem sie sich explizit den NutzerInnen der Tafeln in Deutschland zuwendet. Eine intensive und durch einen quantitativen Ansatz stärker verallgemeinerbare Untersuchung dieser bereits fast eine …
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Investigation and modeling of uranium polarization for the electrorefining of Scrap U-MO foils
… polarization and kinetic parameters such as Tafel constant, transfer coefficient and exchange current density are required. Uranium polarization was investigated at five temperatures and three scan rates in both the anodic and cathodic directions. Anodic polarization of uranium revealed …
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Desenvolvimentos e caracterizações de materiais alternativos para eletrólise da água
… (EDS), difratometria de Raios-x e curvas de Tafel. O levantamento das curvas de Tafel foram realizados em modo galvanostático, aplicando-se saltos sucessivos de correntes monitorados através de um software especificamente desenvolvido para eliminar as contribuições de queda Ôhmica. Os …
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Electrodeposition and characterization of metals and metal oxides for energy conversion and storage
… to be a more active catalyst than CoOOH based on Tafel analysis. However, when the observed current densities are corrected for the measured electrochemically active surface area, the linear region of the two Tafel plots fell on the same line--suggesting the active species, likely Co(IV), for the …
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Study of Faradaic Reactions Occurring At Polycrystalline Platinum Electrode Surfaces in Frozen, Aqueous Acidic Electrolyte
… new results on the comparison of different Tafel plot acquisition methods for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), hydrogen oxidation reaction (HOR), and oxygen reduction reaction (ORR) at polycrystalline Pt (Pt(poly)) in frozen and liquid aqueous H2SO4 …
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Indium-based thiospinels via solid-state pyrolysis of metal-organic precursors for water splitting and supercapacitance
… with an η of 138 mV at 10 mA/cm2 and a Tafel slope of 118 mV/dec. In terms of OER performance, an η of 382 mV at 10 mA/cm2 was obtained along with a Tafel slope of 145 mV/dec. Furthermore, the scalable fabrication of compositionally-tuned Ni1-xCoxIn2S4 solid solutions through the …
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Oxygen evolution mediated by co-based thin film electrocatalysts
… experiments. The catalyst exhibits an OER Tafel slope approximately equal to 2.3 x RT/F, an inverse first order dependence on proton activity, and a zeroth order dependence on phosphate for buffer strengths > 0.03 M. In the absence of phosphate, the Tafel slope increases ~3 fold and the …
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Mesoporous oxides as efficient catalysts for the electrocatalytic oxygen evolution reaction (OER)
… the influence on kinetic parameters such as Tafel slope was investigated. High OER-activities and low Tafel slopes were found for materials with low crystallinity, high surface area, high conductivity and electrocatalytic measurements conducted at moderate overpotentials (ca. η < 0,35 V). In …
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Electro-reduction of bromate on mercury
… The steady state kinetic parameters include Tafel slopes of ca. -0.120 V, approximate first order activity dependences for both BrO⁻₃ and the accompanying cation, and no pH dependence. A reaction scheme is proposed which involves BrO⁻₃ "bridged" to the electrode by the accompanying cation. It …
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Electrochemical Hydrogen Absorption by Zr-Cu-Al-Ni Metallic Glasses
… of amorphous Zr-based alloys as derived from Tafel plots reveals three characteristic potential regions reflecting the different mechanisms of hydrogen on the surface. In the Tafel region, hydrogen discharge and adsorption takes place on the alloy surface as fast steps reactions followed by …
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Fabrication of PtNi and PtV near-surface alloys as improved catalysts for proton exchange membrane hydrogen fuel cells
… in the form of iron, manganese and chromium. Tafel Plot analysis was used to gather electrochemical data for the NSAs. In this regard, the hydrogen reduction (evolution) reaction was analyzed with the exchange current density extracted experimentally therefrom. This technique confirmed that Pt …
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Experimental and Theoretical Investigation of Pitting Corrosion of Nickel in Chloride Solution
… dissolution was simulated with use of the Tafel expression and found to represent adequately the experimental data over the range of potentials studied.
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Kinetic Studies of Sulfide Mineral Oxidation and Xanthate Adsorption
… angle measurements, cyclic voltammetry and Tafel studies have been used to elucidate the depressing action of DETA and SO2. It was observed that DETA and SO2 complement each other in maintaining lower pulp potentials and removing polysulfides. DETA also helps in deactivating pyrrhotite. …
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The Role of Surface Coverage of Reaction Intermediates in Heterogeneous Electrocatalysis
… mechanistic parameters, reaction orders and Tafel slopes. On heterogeneous catalysts, lateral interactions between neighboring intermediates can lead to non-linear correlations between reaction conditions and the overall reaction rate, and complicate the mechanistic analysis. To avoid this …
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The Federal Gamble: The Russian Federation in Comparative Perspective
"In examining the longitudinal processes in countries that experienced simultaneous regime change and federalization, this study adopts a most-different systems research design across the cases of the Soviet Union (confederalism and collapse), Russia (""exclusive bilateralism""), Brazil …
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Structural and mechanistic studies of nickel-borate thin-film oxygen evolving electrocatalysts
… indicate that the as-deposited Ni-Bi exhibits a Tafel slope close to 2.3 x 2RT/F, consistent with a turnover-limiting electron transfer (ET) from the geometrically distorted low-spin d⁷ Ni(III) state. Upon anodization to the mixed valence Ni(III/IV) state and elimination of geometric distortion, …
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Investigation of New, Low-Voltage, Aluminum, Sacrificial Anode Chemistries
… potential, potentiostatic, galvanostatic and Tafel tests were performed on eleven high-purity aluminum-based binary and ternary alloys containing Bi, Ga, In and Zn in an effort to understand the individual effects of each element and the interactions between these elements. The microstructures …
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Electrochemical corrosion testing of boronized and unboronized steels
… tested in these solutions. Linear Polarization, Tafel plots and Cyclic Polarization were the three techniques used to analyze the corrosion resistance of boronized and unboronized steels. Comparative studies revealed increase in corrosion resistance of AISI 1018 by 3-8 times, of AISI 4340 by 3-10 …
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Nikelio ir jo lydinių katalizatorių charakterizavimas ir pritaikymas vandens skaldymo reakcijoje /
… overpotential of 352 mV at 10 mA cm-2 and a Tafel slope of 79 mV dec-1. In the oxygen evolution reaction (OER), Ni80Fe8P12 and Ni75Fe12P12 demonstrated significant efficiency, correlating the catalytic performance to the iron content within the catalyst. This study underscores the critical …
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Reference Electrode Development in Polymer Electrolyte Membrane (PEM) Electrolyzer Assembly for Novel Investigation of Electrodes
… at the anode and cathode, respectively. Tafel slopes were calculated and the rate determining steps were determined that support specific proposed reaction mechanisms reported in literature. This investigation revealed important characteristics of each electrode. In particular, it was …
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