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International audience; Some of hazardous liquid organic wastes, radioactive or not, are waiting from outlet to be destroyed. The ELIPSE process is a new technology of organic liquid destruction, involving a thermal plasma working under a water column, which ensures the cooling, the filtration and the scrubbing of the gases coming from the degradation. This study deals with the ability of the ELIPSE process to destroy the pure organic liquids and then to reduce the amount of organic matter remaining in the aqueous solution by means of the thermal or radiative properties of plasma. Preliminary test have shown how efficient the process is for the destruction of the organic liquids when they are directly fed in the plasma hearth. Extensive researches have been performed to assess the ability of the submerged plasma to destroy the remaining organic matters either by reinjecting them with the aqueous solution into the plasma or by using the UV ray coming from the plasma itself. A comparison of the experimental results obtained with various mechanisms proposed by the work carried out highlighted that this UV radiation could, by excitation of water molecules, produce radicals OH which may either dimerise to produce hydrogen peroxide H$_2$O$_2$, or react with organic substances present. The calculation of an activation energy of 8.5 $\pm$ 0.9 kJ mol$^{−1}$ during the experiments shows that these radicals OH$^\circ$ act directly after having been formed which explains a low H$_2$O$_2$ content stability when the solution contains organic compounds. Thus, this photo-oxidation taking place in the water column could be used to improve the destruction of residual organic matter in the solution by maintaining the plasma after processing a given amount of organic liquids.

When modeling plasma turbulence, two different means of driving the system out of equilibrium are considered. On one hand, flux driven (FD) approaches are based on the idea that no scale separation can be assumed in a turbulent system. On the other hand, gradient driven (GD) approaches rely on the idea that the back-reaction of fluctuations on the mean profiles is not a critical ingredient for turbulence self-organization and saturation. We find that FD and GD systems strongly differ in regimes close to marginal stability. The characteristic non linear upshift is recovered in GD simulations but no comparable behavior is possible in FD case. Discrepancy between the various analysis in terms of diffusion and pinch velocities and between the models is also discussed.

Ce chapitre fait le point sur les restructurations en cours au sein d'une catégorie d'acteurs spécifiques au système productif nippon, le groupe multisectoriel (GMS). Il rappelle d'abord en quoi les GMS apparaissent au plan national comme les promoteurs d'un mode de gouvernance spécifique des activités productives et comme des acteurs dont la sphère d'influence stratégique demeure considérable. Il voit alors comment, dans la période actuelle, la mondialisation et la crise financière japonaise affectent les GMS. Enfin, il s'interroge sur l'impact des restructurations en cours et sur possibilités du maintien ou non d'un mode de gouvernance spécifique.