Three-dimensional separation in shock/boundary layer interaction

A Large-eddy simulation of a shock impinging on a turbulent boundary layer is carried out and demonstrates good agreement with the experiments. A special emphasis is put on the analysis of the three-dimensional modulation of the flow in order to clarify the origin of the mean vortices located in the separation region highlighted by the experimen

Fostering Energy Efficiency in manufacturing plants through economical breakthroughs in power and flow rate measurement

International audienceThe ability to measure, monitor and control energy consumption at several key locations in a manufacturing plant is a major prerequisite for any efficient energy management program. To identify and evaluate energy savings, one must get a clear view of how the energy is used. Furthermore, measuring energy flows is one of the necessary conditions for long lasting energy-efficient solutions. Most of the time energy managers are reluctant to put in place power and flow rate measuring devices either because of their cost or because this implies disrupting production. To find acceptable and economical solutions for long lasting energy measurements in Industry, EDF R&D launched a 3-year collaborative research project called CHIC. This project is funded by the French National Research Agency (ANR) and involves 7 partners. Its total budget amounts to 2.55 M€. Because energy measuring devices acceptability relies mostly on their ability to be installed without disrupting production as well as on their installation and maintenance costs, two non intrusive and low cost technologies will be explored within the project: A physical approach is being used to build a clamp-on power meter that could be installed around multi-conductors power cables without interrupting power supply, A software based approach is being used to build power and flow meters that derive the sought-for variable from models and from simple and easy to collect other physical measurements (e.g. command signals, etc...). Introductio

The "Ram Effect": A "Non-Classical" Mechanism for Inducing LH Surges in Sheep

During spring sheep do not normally ovulate but exposure to a ram can induce ovulation. In some ewes an LH surge is induced immediately after exposure to a ram thus raising questions about the control of this precocious LH surge. Our first aim was to determine the plasma concentrations of oestradiol (E2) E2 in anoestrous ewes before and after the "ram effect" in ewes that had a "precocious" LH surge (starting within 6 hours), a "normal" surge (between 6 and 28h) and "late» surge (not detected by 56h). In another experiment we tested if a small increase in circulating E2 could induce an LH surge in anoestrus ewes. The concentration of E2 significantly was not different at the time of ram introduction among ewes with the three types of LH surge. "Precocious" LH surges were not preceded by a large increase in E2 unlike "normal" surges and small elevations of circulating E2 alone were unable to induce LH surges. These results show that the "precocious" LH surge was not the result of E2 positive feedback. Our second aim was to test if noradrenaline (NA) is involved in the LH response to the "ram effect". Using double labelling for Fos and tyrosine hydroxylase (TH) we showed that exposure of anoestrous ewes to a ram induced a higher density of cells positive for both in the A1 nucleus and the Locus Coeruleus complex compared to unstimulated controls. Finally, the administration by retrodialysis into the preoptic area, of NA increased the proportion of ewes with an LH response to ram odor whereas treatment with the α1 antagonist Prazosin decreased the LH pulse frequency and amplitude induced by a sexually active ram. Collectively these results suggest that in anoestrous ewes NA is involved in ram-induced LH secretion as observed in other induced ovulators

Recherche opérationnelle et gestion de la production

Depuis leurs origines, la recherche opérationnelle et la gestion de la production entretiennent des relations privilégiées. Historiquement, la gestion de la production et les domaines connexes de la logistique industrielle ont d'ailleurs rapidement supplanté la gestion des opérations militaires comme champ d’action principal et, simultanément, comme catalyseur du développement de la recherche opérationnelle. L'article offre un très bref aperçu des applications de la recherche opérationnelle en gestion de la production. Il est organisé autour de trois thèmes principaux, à savoir: planification de la production et programmation mathématique, gestion des stocks et conception de systèmes

Ordonnancement de projet

International audienc

Branch and bound algorithm for the simple warehouse location problem with concave cost

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Amélioration continue : quelles démarches et techniques ?

International audienc

Amélioration continue : quelles démarches et techniques ?

International audienc