Articles techniques et présentations

The present article presents a method to redistribute the acoustic modes of a rectangular enclosure in the low frequency range using slit resonators. The objective of the present work is to compare different strategies of optimal design in order to determine the dimensions of the ... En savoir plus

Surface breaking cracks in conductive structures can be detected by conventional eddy current techniques. However, it is very difficult to detect inner layer defects in multilayered conductive structures either by conventional eddy current or ultrasonic methods. The transient/pulsed eddy ... En savoir plus

In this paper, PEM fuel cells with serpentine and interdigitated flow channel patterns were studied. The main objective was to analyze the influence of the flow channel design in the current distribution over the cell. A 3D isothermal model comprising the entire 5 cm² cell was developed ... En savoir plus

The objective of this study is to determine the locations where liquid water accumulates at cathode gas flow channels, and the corresponding operating conditions. In such way it is possible to mitigate slug flow, responsible for channel blockage and hindering the diffusion of reactants ... En savoir plus

VRALA is the ideal candidate as an Adaptive Optics actuator at visible wavelengths. Its electric characteristics variations, suitable current commands, and an effective magnetic circuit geometry provide a 2 kHz correction bandwidth and a 25 mm actuator density. The magnetic core allows ... En savoir plus

The technology involved in high performance ultrasound imaging probes needs a reliable model to help in new projects development and performance simulations. To achieve a useful model, it is necessary to use correct values for all material parameters involved in the electro-acoustical ... En savoir plus

The present paper describes the development of a full FEM model for linear array high performance 5MHz ultrasound imaging transducer. As a preliminary design, a mono dimensional electro-acoustical KLM model was realized, then the complete FEM was developed and optimized. The optimized ... En savoir plus

Metacomposites are new class of materials with unusual properties that can be engineered using existing materials with usual properties. The unusual properties of metacomposites are derived from the structure, analogues to atomic arrangement in crystal lattice. These material exhibits ... En savoir plus

This work is concerned with systems possessing cyclic symmetries. In particular, we concentrate on the case in which the medium possesses infinite order cyclic symmetry, while the constitutive relations have cyclic symmetry of a lower order. We investigate the interactions between modes ... En savoir plus

We perform EM simulations of a low-pass microstrip filter consisting of a cross-junction open stub and two unit sections implemented as defected ground structures (DGS). The defect introduced by unit sections corresponds to an etched lattice on the copper backside ground plane. The ... En savoir plus