In this paper, we propose the modeling of an industrial gas sensor “MQ-9”, where our modeling is based on ANNs “artificial neural networks The gas sensor model, obtained, operated under a dynamic environment and expresses accurately the MQ-9 gas sensor behavior. Accordingly, it takes into account the nonlinearity and the cross sensitivity in gas selectivity, temperature and humidity. This model is implemented into PSPICE “performance simulation program with integrated circuit emphasis” simulator as an electrical circuit in order to prove the similarity of the analytical model output with that of the MQ-9 gas sensor.

In this paper, we propose a new numerical method for acoustics microwaves detection of an acoustics microwaves signal during the propagation of acoustics microwaves in a piezoelectric substrate Zinc oxide (ZnO) . We have used Support Vector Machines (SVM) ,the originality of this method is the accurate values that provides .this technic help us to identify undetectable waves that we can not identify with the classical methods; in which we classify all the values of the real part and the imaginary part of the coefficient attenuation with the acoustic velocity in order to build a model from which we note the types of microwaves acoustics( bulk waves or surface waves or leaky waves) . By which we obtain accurate values for each of the coefficient attenuation and acoustic velocity. This study will be very interesting in modeling and realization of acoustics microwaves devices (ultrasound ,Radiating structures , Filter SAW ….) based on the propagation of acoustics microwaves.

Dans l’étude présentée dans ce travail, on a mené une étude numérique de la convection naturelle dans une enceinte rectangulaire verticale simulant un thermosiphon. La cavité étant remplie de métal liquide. En se basent sur les approximations de Boussinesq et les équations de conservation de masse, de quantité de mouvement et d’énergie, on a développé le modèle mathématique décrivant notre problème. On a mené les simulations numériques en utilisant le code FLUENT qui se base sur la méthode des volumes fins. Un premier travail de validation a été réalisé en comparant nos résultats avec ceux d'autres auteurs. Une étude paramétrique de la convection naturelle dans une cavité avec ailette a été également menée.

Bone, like any other material, is subject to mechanical fatigue when subjected to repetitive cyclic loading. Cyclic loading in vivo occurs either in workplaces exposed to mechanical vibration or during handling operations or during leisure and sports activities. As an example, the continuous exposure of the human body to intense global vibration can be, in the long run, cause problems of lumbar lesions due to dynamic stresses (mainly compression) in the spine. Bone and microcracks in cancellous bone. Fatigue rupture of vertebral bone is clinically and biologically important. From a clinical point of view, permanent damage and deformity, under cyclic loading, can probably weaken the vertebral body by inducing the migration of joint replacements. The mechanism of fatigue damage in cortical and trabecular bone can cause cracks and their propagation to final rupture. Microcracks observed in the vertebrae contributed to the decrease in vertebral rupture strength. In order to analyze the biomechanical behavior of the vertebrae and to assess the risk of fracture, an in vivo characterization method is applied based on the micro-MRI, aiming to focus on the evaluation the force at rupture of the vertebral body in compression. The method of extracting the shape of cancellous bone by special filters (adaptive filter, Robert's filter, etc.) will be applied, allowing it to be modelled as a slice (2D). This micro slice are created by edge configuration generation and triangulated cube configuration generation in capturing section contour points from medical image per slice, creating B-spline curve with the control points in each layer, producing solid model construction in Planar Contours method. Medical rapid prototyping models are performed in SolidWorks. Layered manufacturing techniques are used for producing parts of arbitrary complexity, which will then be modelled by finite element in fatigue