Browsing by Issue Date, starting with "2019-04-15"
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- Nickel-cobalt oxide modified with reduced graphene oxide: Performance and degradation for energy storage applicationsPublication . Adan-Mas, Alberto; Moura E Silva, Teresa; Guerlou-Demourgues, Liliane; Bourgeois, L.; MONTEMOR, FATIMANickel-cobalt oxide is synthesized in combination with electrochemically reduced graphene oxide (Er-GO) by one-step electrodeposition on stainless steel followed by thermal treatment. The presence of reduced graphene oxide leads to enhanced electrochemical response, with a capacity increase from 113 mA h g(-1) to 180 mA h g(-1), and to increased faradaic efficiency and rate capability. Compared to Ni-Co oxide, the addition of reduced graphene oxide increases capacity retention from 58% to 83% after 5000 cycles. The material fade during cycling is studied by means of electrochemical impedance spectroscopy, electron diffraction spectroscopy and scanning electron microscopy. As a result, different degradation mechanisms are identified as source of the capacity decay, such as microstructural cracking, phase transformation and parasitic reactions.
- Numerical analysis of the vibration response of skew magneto-electro-elastic plates based on the higher-order shear deformation theoryPublication . Vinyas, M.; Nischith, G.; Loja, Amélia; Ebrahimi, Farzad; Duc, N. D.This work addresses the problem of the three-dimensional free vibration behavior of skew magneto-electro-elastic plates under the framework of a higher order shear deformation theory. To this end, the finite element method was adopted considering the Hamilton's principle. The results obtained from the present finite element model are verified with the simulation results of COMSOL software. Further, a parametric study is carried out to evaluate the influence of boundary conditions, stacking sequence, aspect ratio, and the length-to-width ratio. A special emphasis has been given to the natural frequency characteristics of multiphase skew magneto-electroelastic plates as well. The results from the present analyses allow concluding on the significant influence that the geometrical skewness has on the free vibration behavior of these plates.