Search results for "Engineering sciences"
showing 10 items of 2347 documents
Study and Simulation of Helicopter Gearboxes Noise
2010
International audience; Main gearbox is one of the main noise sources in helicopter cabin. In order to improve the comfort of customers and reduce the health impact, acoustic and vibration mechanisms of gearboxes have to be understood and simulated during development phases. Thus, we first present the global methodology chosen to compute main gearboxes noise in helicopter cabins. Secondly, we described the way we compute mechanical excitation sources induced from gear mesh, static transmission error and meshing stiffness. Depending on the type of gear, we compute those using either analytical specially developed code or EC codes. Thirdly, we propose a modeling to compute dynamic loads on be…
Aliasing-Free and Additive Error in Mixed Spectra for Stable Processes. Application: Sound of a Bird just captivated in stress
2022
Consider a symmetric continuous time α stableprocess observed with an additive constant error. Theobjective of this paper is to give a non-parametric estimatorof this error by using discrete observations. As the time ofprocess is continuous and the observations are discrete, weencountered the aliasing phenomenon. Our process sampleis taken in a way to circumvent the difficulty related toaliasing and we smoothed the periodogram by using JacksonKernel. The rate of convergence of this estimator is studiedwhen the spectral density is zero at origin. Few long memoryprocesses are taken here as examples. We have applied ourestimator to the concrete case of modeling noise of a birdcaptured under st…
Fiber-based optical functions for high-bit-rate transmissions
2008
oral
Récents développements des fibres microstructurées en verres de chalcogénure
2009
oral
Recent advances in chalcogenide holey fibres
2010
oral
Recent advances in chalcogenide holey fibres
2009
oral
Elaboration by casting method of low losses chalcogenide microstructured fibers for near and mid infrared applications
2010
oral session C " Preparation and Property ", oral [TuA-16]; International audience
Chewing simulation: a way to understand the relationships between mastication, food breakdown and flavour release
2010
International audience; Understanding in-mouth mechanisms is necessary to understand flavour release and perception phenomena. To overcome the limitations of in-vivo flavour release measurements, we developed a chewing simulator that faithfully reproduced many mouth functions. Using brittle foods, we showed that in-vitro food breakdown was very comparable to that obtained in-vivo. We also studied on model cheeses in-vitro flavour release by connecting on-line the chewing simulator to APCI-MS. Preliminary results are discussed.
Comportement en fatigue des composites en lin/époxy
2011
International audience; Le travail présenté s'intéresse à la caractérisation des propriétés mécaniques quasi-statiques et en fatigue d'un composite stratifié en lin/époxy. Les éprouvettes fabriquées par thermocompression ont des séquences d'empilement de 0/90° et ±45° pour les essais de traction uniaxiale et cisaillement plan respectivement. Les essais quasi-statiques révèlent une variabilité des propriétés mécaniques de l'ordre de 10%. Les essais de fatigue en traction et en cisaillement plan ont été réalisés pour des niveaux de contraintes compris entre 40 et 80% des valeurs ultimes du composite (US). L'étude des boucles d'hystérésis a mis en évidence une plastification plus importante en…
Piecing together the taste signaling puzzle
2010
International audience; The identification of the genes coding for bitter, umami, sweet and sour taste receptors has provided us with unique tools to investigate the gustatory system. As a consequence, tremendous progress towards our understanding of the functional organization of the peripheral taste system has been achieved over the past decade. In particular, key components of the taste receptors signaling cascades have been identified as well as populations of chemosensory cells in the olfactory, respiratory and digestive systems expressing taste receptors. Besides sharing receptors and signaling molecules (gustducin, phospholipase-C b2…) with taste bud cells, these cells display a simi…