Businesses as one of the key elements of a regions sustainable development.

International audienceThe regionalization and local development, encouraged by the European Union involves the notion of territory. Today territory or region should be seen as a system of actors. The concept of sustainable development should be taken into account by these actors. Businesses (especially SMEs) whose aim is to assure local development, economic growth and job creation are one of the key elements of territorys sustainability.La régionalisation favorisée par lUnion Européenne implique la notion de territoire. Des acteurs sexpriment dans des systèmes complexes et le concept de développement durable doit être globalement pris en compte. Les entreprises, acteurs de ces territoires pour assurer le développement économique et lemploi, se retrouvent au cur de la problématique de développement durable

Scholte-Stoneley waves on corrugated surfaces and on phononic crystal gratings

International audienc

Tunable waveguide and cavity in a phononic crystal plate by controlling whispering-gallery modes in hollow pillars

International audienceWe investigate the properties of a phononic crystal plate with hollow pillars and introduce the existence of whispering-gallery modes (WGMs). We show that by tuning the inner radius of the hollow pillar, these modes can merge inside both Bragg and low frequency band gaps, deserving phononic crystal and acoustic metamaterial applications. These modes can be used as narrow pass bands for which the quality factor can be greatly enhanced by the introduction of an additional cylinder between the hollow cylinder and the plate. We discuss some functionalities of these confined WGM in both Bragg and low frequency gaps for wavelength division in multiplexer devices using heteroradii pillars introduced into waveguide and cavity structures

Pillar-type acoustic metasurface

International audienceWe theoretically investigate acoustic metasurfaces consisting of either a single pillar or a line of identical pillars on a thin plate, and we report on the dependence on the geometrical parameters of both the monopolar compressional and dipolar bending modes. We show that for specific dimensions of the resonators, a bending and a compressional modes may be simultaneously excited. We study their interaction with an anti-symmetric Lamb wave, whether or not they occur at the same frequency, with particular consideration for the amplitude and phase of waves emitted by the pillars at resonance. Especially, the analysis of both the amplitude and the phase of the wave at the common resonant frequency downstream a line of pillars, demonstrates that the reemitted waves allow for the transmission with phase shift of π

Altered subcellular reactions to stress after a long-term human exposure to antarctic condition

Medical research in Antarctica opens up new horizons to study individual health and reactions under stress and unusual environmental conditions. A long stay in Antarctica can evoke reactions associated with adaptation to hypoxia and mitochondrial dysfunction, determined by a set of molecular-genetic mechanisms. The aim was to study the changes in platelet ultrastructure in Antarctic winterers under hypoxic loading, and the ultrastructure of mitochondria (MT) of leukocytes in winterers, depending on the length of exposure to Antarctic conditions and number of expeditions participated. We included to the study 24 winterers, who once stayed in Antarctica during 1 year (group 1), 3-4 one-year stays (group 2), and 5-7 one-year stays (group 3). The control group included 8 men, who were not exposed to adverse environmental factors and never visited Antarctica.  We assessed the ultrastructure of platelet and leukocytes before and after the hypoxic loading. The background characteristics of the ultrastructure of platelets and leukocytes of winterers. Significant changes developed in the platelet and leukocytes mitochondria ultrastructure after hypoxic loading. The severity of changes in leukocyte mitochondria correlated with number of expeditions participated, and manifested by development of autophagy, apoptosis up to irreversible organelle changes, a partial or complete vacuolization, excessive swelling of organelles after 1 year stay, 3-4, and 5-7 one-year expeditions respectively. So, a long exposure to Antarctic conditions is associated with mitochondrial dysfunction