Full-Heuslers are a group of materials that have repeatedly attracted the curiosity of scientists and researchers, especially for their use in the field of spintronics. In this work, we undertook a study on the structural, elastic, electronic, magnetic and thermodynamic properties of the full-Heusler Mn2OsGe alloy using the calculations of the first principles. Two approximations are used: the generalized approximation of the Perdew–Burke–Ernzerhof GGA–PBE gradient for electron-correlation exchange and the new modified Tran-Blaha form of the modified Becke-Johnson mBJ–GGA-PBE potential. As important results, we found that the compound Mn2OsGe is stable in the CuHg2Ti structure; on the other hand, we could also verify its mechanical stability at zero temperature and pressure. For the calculation of the electronic properties, we were able to determine the half-metallic ferrimagnetic character of our compound, which exhibits a metallic behavior in the state of the majority spins, and a semiconductor behavior in the state of the minority spins. An integer value of 2[Formula: see text][Formula: see text] has been recorded for a magnetic moment and this conforms to the Slater–Pauling rule.

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An automobile brake disc brought into contact with the pads, mechanical stresses are imposed on the contact surface. These stresses can cause degradation by fatigue, rupture, wear, propagation of cracks. Modeling the numerical results makes it possible to recognize this damage in order to improve the braking system, extend its service life, reduce the cost of maintenance and make it more reliable. The aim of our study concerns modeling and numerical simulation using ANSYS 14.5 software based on the finite element method under the influence of certain essential parameters on the braking behavior of the torque as a function of geometric parameters, properties mechanical, boundary conditions, type of loading applied, type of materials chosen and type of analysis carried out in braking torques (ventilated drilled disc / pads and ventilated grooved disc / pads), upon contact with a disc in rotation with a plate which represents the friction body on the disc. The behavior of the torque during braking was analyzed in terms of stresses and deformations, and displacements, the comparison between the two types of discs was also discussed.  

The present work, constituted a theoretical study of the phenomenon of the electric conductivity of composite conducting polymers. Generally, the polymers are used as electrical insulators. The incorporation of conducting loads in an insulating polymeric matrix makes it possible to obtain materials having at the same time a high electric conductivity and a low density. These materials offer a great number of applications such as the electromagnetic shielding, the protection of metals against corrosion, the adhesives conducting, the connectors, the sensors, etc. The prediction and modelling of the electrical behaviour of these composite materials are needed for the choice of their scope and could therefore reduce the onerous experimental work and the cost of production through an optimized design. We carried out a theoretical study. To make this study, we are based on experimental results existing in the specialized literature and we build a new ideal model which describes the variation of electrical conductivity in function the voluminal fraction of the conducting loads. The comparison between our ideal model suggested and other models of McLachlan, Kirkpatrick and Landauer, shows that the model suggested is in concord with the experimental results.