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The dynamics of the nonlinear electromechanical device, consisting of a mechanical part with two outputs and an electrical part which acts as the server is strongly investigated in the present work. The mechanical part consists of two nonlinear oscillators with strong irrational nonlinearities having smooth or discontinuous characteristics, where nonlinearity is just due to the inclination of springs, the geometric configuration, which are both elastically coupled. While the electrical part is the Rayleigh equation. By using the Lagrangian formulation, the model equations are established and used to investigate the equilibrium points and their stabilities. Nest by using the multiple time scales method, the analytical solutions are found both for the case of large amplitude and the weak amplitude, leading to interesting bifurcation sets of the equilibria by varying the control parameters, the inclination angles and driven frequency. Finally, numerical investigations of the exact equation of the system are used to justify the validity of analytical results and to find new phenomena such as chaotic impulses, chaotic bursting and the train of kink signal generations.

The excessive consumption of energy in the building sector weighs heavily on the energy bill of the developing countries. It is for this reason that several studies have been carried out at the international level, both at the level of building's envelope and equipments, in order to contribute to the control of energy. In this study, we are interested in studying the effect of cow's dung on the thermo-physical characteristics of materials based on clay in the region of Abeche (Chad). The goal is to obtain light weighs samples with better thermal performance, which can contribute to improve the thermal comfort in traditional constructions in Chad and to reduce the use of cereal's straw and pods. Since these are used to feed livestock. The experimental study that we have conducted has enabled us to determine the conductivity, the effusivity and the thermal diffusivity of our samples. Our experimental data show a good efficiency and a significant decrease in the thermal conductivity of material with cow's dung compared to simple clay material.