Anodic Characteristics of Copper, Wrought CuNi10, and CuAl10Ni5Fe4 in Seawater: Part 1—Polarizations Below 200 mV at Rotating Disc Electrodes and Rotating Cylinder Electrodes

CORROSION ◽  
2009 ◽  
Vol 65 (1) ◽  
pp. 24-36 ◽  
Author(s):  
G. Kear ◽  
B. D. Barker ◽  
K. R. Stokes ◽  
F. C. Walsh
2017 ◽  
Vol 829 ◽  
pp. 328-344 ◽  
Author(s):  
V. D. Borisevich ◽  
E. P. Potanin ◽  
J. Whichello

A model of a laminar viscous conducting flow, near a dielectric disc in a uniform magnetic field and in the presence of external rotation, is considered, where there is a uniform suction and an axial temperature gradient between the flow and the disc’s surface. It is assumed that the parameters of the suction or the magnetohydrodynamic (MHD) interaction are such that the nonlinear inertial terms, related to the circulation flow, are negligible in the differential equations of the MHD boundary layer on a rotating disc. Analysis of the motion and energy equations, taking the dependence of density on temperature into account, is carried out using the Dorodnitsyn transformation. The exact analytical solution for the boundary layer and heat transfer equations is obtained and analysed, neglecting the viscous and Joule dissipation. The dependence of the flow characteristics in the boundary layer on the rate of suction and the magnetic field induction is studied. It is shown that the direction of the radial flow in the boundary layer on a disc can be changed, not only by variation of the ratio between the angular velocities in the external flow and the boundary layer, but also by changing the ratio of the temperatures in these two flows, as well as by varying the hydrodynamic Prandtl number. The approximate calculation of a three-dimensional flow in a rotating cylinder with a braking disc (or lid) is carried out, demonstrating that a magnetic field slows the circulation velocity in a rotating cylinder.


2012 ◽  
Vol 80 (11) ◽  
pp. 891-897 ◽  
Author(s):  
Takeshi YANE ◽  
Akira KOYAMA ◽  
Kenta HIRAMATSU ◽  
Yoshitaka ISOGAI ◽  
Keigo ICHINOSE ◽  
...  

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 566 ◽  
Author(s):  
Eliran Hamo ◽  
Avichay Raviv ◽  
Brian A. Rosen

The structure sensitivity of the alkaline oxygen reduction reaction (ORR) on palladium is of great interest as cost considerations drive the need to find a replacement for platinum catalysts. The kinetics of alkaline ORR were investigated on nanocrystalline palladium (Pd) films with domain sizes between 14 and 30 nm that were synthesized by electrodeposition from aqueous electrolytes. Ten Pd films were prepared under varying electrodeposition parameters leading to each having a unique texture and morphology. The sensitivity of initial alkaline ORR kinetics to the Pd surface structure was evaluated by measuring the kinetic current density and number of electrons transferred for each film. We show through scanning electron microscopy (SEM), x-ray diffraction (XRD), atomic force microscopy (AFM), and voltammetry from rotating disc electrodes (RDEs) that the fastest alkaline ORR kinetics are found on Pd surfaces with high surface roughness, which themselves are composed of fine grains. Such a study is useful for developing membrane electrode assemblies (MEAs) based on directly electrodepositing catalyst onto a conductive diffusion layer.


A general computational strategy is presented for the calculation of the chronoamperometric responses arising from potential-step experiments at rotating disc electrodes. The method is applicable to a wide range of electrode reaction mechanisms and theoretical results are given for single- and double-potential-step experiments for ECE, DISP1, DISP2, EC' and CE reactions. For the last, the treatment is extended to cover the case where reactants have grossly unequal diffusion coefficients. Steadystate behaviour is also deduced. The extent to which the various mechanistic pathways can be distinguished is identified and the necessary experiments defined.


Author(s):  
Richard G. Compton ◽  
Richard G. Harland ◽  
Patrick R. Unwin ◽  
Andrew M. Waller

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