Articles techniques et présentations

COMSOL Multiphysics® has proven to be an invaluable “virtual laboratory” tool in assisting our development of a new generation of efficient analytical models describing the acoustics of highly porous fibre and foam materials. From the definition of the physical relations describing the ... En savoir plus

A concept of an adaptive sound absorbing material is proposed and investigated numerically using the COMSOL Multiphysics® Software suitable for the required advanced dual-scale modelling which involves solution of various problems of physics at the microscopic and macroscopic levels. A ... En savoir plus

One of the main design questions in loudspeaker enclosures concern vibrations reduction. An ideal cabinet would be infinitely rigid, so a section of an engineer work is focused on this goal. Solutions depend by loudspeaker system audio field: Line Arrays, Automotive environments or hi ... En savoir plus

Microfabricated planar interdigitated electrodes can detect and analyze cells or particles giving an impedance-based characterization. This method presents several advantages: real-time detection, label-free analysis, non-invasive sensing, easiness of integration and high-throughput ... En savoir plus

For automotive applications, simulations are used to optimize the position and orientation of a subwoofer (loudspeaker) in a very constrained space to get the best acoustic performances. One solution is to use particular part of the BIW volume as the subwoofer enclosure. The acoustical ... En savoir plus

Various types of FI-Relays are built in electrical protective residual current devices (RCD). They are all electromechanical assemblies that trip at appearance of residual currents (i.e. fault or earth leakage current) and consequently break main contacts of RCD. FI relays are very ... En savoir plus

Snow can exist in a wide range of temperatures. Its behavior changes especially around its melting point. A better understanding for wet snow is essential for snow pack stability, the effect of water percolation and friction between ski and wet snow surface. Technical details about ... En savoir plus

The growing demand for efficient transmission (1), including refurbishing of existing lines, requires technological advances beyond the actual methodologies, basically electric parameters and electromagnetic fields estimation. Some analytical models developed at CEPEL (2, 3) provide ... En savoir plus

Finite element modelling of surgical transducers has been performed and is described. Ultrasonic transducers vibrating at around 25 kHz are used in orthopaedic surgery to cut bone. The high acoustic impedance of the metal blades used in these devices couples energy more efficiently to ... En savoir plus

Ultrasonic acoustic waves usually encounter interfaces with significant impedance mismatch in practical medical or industrial imaging applications. A transparent interface can help to improve the performance of medical and industrial imaging and overall innovative applications. ... En savoir plus