European Master in Nuclear Energy (EMINE). When academy and industry meet

EMINE master programme is an international education initiative offered by KIC-InnoEnergy under the framework of the European Institute of Innovation and Technology (EIT). Students in the programme have the opportunity to acquire an in-depth knowledge of the nuclear industry, through unique and specialised courses covering a wide range of subjects. Students choose between UPC (Barcelona) and KTH (Stockholm) for the first year and between Grenoble-INP and Paris-Saclay University (France) for the second year. Grenoble École de Management (GEM) completes the list of academic partners: students take a 3-week summer course on energy management issues after their first year in EMINE. EMINE students also benefit from the involvement of our industrial partners (AREVA, EDF, ENDESA, INSTN-CEA, and Vattenfall) in the Programme. For the academic institutions, EMINE is the opportunity to provide a high level education aligned with the industrial needs. The international collaboration among universities helps improving the quality and the adoption of best practices. EMINE attracts good students to our centres whereas the EIT funding and the industrial involvement allows a number of activities that otherwise would have been difficult to carry out, such as the assistance of external industrial experts or field activities. MSc EMINE helps tomorrow’s nuclear engineers take up the challenges the nuclear energy industry faces in terms of safety, social acceptability and waste management. By offering outstanding technical training and addressing the economic, social and political aspects of nuclear energy, the programme broadens the scope of traditional nuclear education.Postprint (published version

Effet de l'ombrage sur le microclimat, la fertilité du sol et la production du caféier au Costa Rica

La culture du café (Arabica) en Amérique centrale est gravement menacée par le changement climatique. L'agroforesterie est présentée comme une solution prometteuse pour lutter contre les événements climatiques extrêmes (températures élevées et fortes pluies) et maintenir un équilibre dans le cycle des nutriments. En revanche aucun type d'agroforêt n'est aujourd'hui connu pour optimiser ces effets. Notre objectif était d'étudier les effets de deux types d'ombrage: E. poeppigiana, couramment utilisé au Costa Rica et un ombrage plurispécifique, sur le microclimat, la fertilité du sol, la croissance végétative et le rendement du caféier, en comparaison à un système plein soleil. L'originalité de cette étude était de quantifier l'énergie cinétique de la pluie dans des systèmes agroforestiers. Nous avons mesuré des énergies cinétiques plus fortes sous ombrage et en particulier sous certains arbres comme Cordia alliodora. D'autres espèces, comme E. poeppigiana ne montrent pas d'effet. De plus en association avec E. poeppigiana, l'effet tampon des températures est plus efficace et la fertilité du sol semble plus favorable, ce qui est cohérent avec le nombre de fruit produit plus élevé que dans les autres plantations. Ce système agroforestier permettrait de mieux s'adapter au changement climatique mais la gestion des caféiers (taille, fertilisation) doit être prise en compte. (Résumé d'auteur

Cooperation, the power of a single word. Some experimental evidence on wording and gender effects in a Game of Chicken

Wording has been widely shown to affect decision making. In this paper, we investigate experimentally whether and to what extent, cooperative behaviour in a Game of Chicken may be impated by a very basic change in the labelling of the strategies. Our within-subject experimental design involves two treatments. The only difference between them is that we introduce either a socially-oriented wording (‘I cooperate'/‘I do not cooperate') or colours (red/blue) to designate strategies. The level of cooperation appears to be higher in the socially-oriented context, but only when the uncertainty as regards the type of the partner is manipulated, and especially among females.Social dilemma, Game of Chicken, cooperation, wording effects, gender effects.

Cooperation in a Game of Chicken with Heterogeneous Agents: An Experimental Study

Using a two-stage Game of Chicken, Cabon-Dhersin and Ramani (2007) examine the impact of population heterogeneity on cooperative behaviour. For that purpose, they introduce two different types of agents, namely those who always cooperate and those who strategically cooperate. The aim of the present experimental study is to investigate the descriptive accuracy of the one-stage version of this model. Even though the level of cooperation appears to be much higher than predicted, our data bring strong support to the main predictions that the structure of the population as well as the structure of the payoffs affect cooperative behaviour

Nanofiltration de solutions de nitrate d'ammonium. Etude des paramètres influents

Cet article propose une étude de la rétention du nitrate d'ammonium par une membrane commerciale de nanofiltration (Nanomax 50). Les effets de la pression, de la concentration et de la vitesse d'écoulement tangentiel ont été étudiés avec le souci d'une meilleure compréhension du mécanisme de transport des ions nitrate et en vue d'une optimisation de la rétention. Le taux de rétention des ions nitrate augmente dans un premier temps avec la pression, atteint un maximum puis diminue. La rétention, pour des pressions élevées, peut cependant être améliorée en augmentant la vitesse d'écoulement tangentiel. La séparation résulterait d'un rapport de différentes forces : une force d'entraînement radial dans le pore (illustrée par l'effet de la pression transmembranaire), une force d'entraînement tangentiel vers le rétentat (illustrée par l'effet de la vitesse d'écoulement tangentiel) et une force de surface traduisant les interactions membrane-soluté (illustrée par l'effet de la concentration). L'équation de Spiegler et Kedem est proposée en première approche de modélisation pour une valeur limite de pression.Many water sources deal with the problem of increasing nitrate concentrations above authorised levels for drinking water. In order to minimise this amount of pollution and to achieve high quality of water and reused water in the distribution system, membrane processes are becoming a promising technology. Indeed, they present the major advantages of a small land area requirement, low temperature operation, continuous separation, better effluent quality, little or no sludge production and a large reduction in the quantities of chemical additives. Reverse osmosis has already been used to remove most of the nitrates together with the other solutes, but the disadvantage is that this technique induces a total demineralisation of the treated water. Another possible filtration process, nanofiltration, has been investigated in this study while no extensive research has been carried out on its nitrate removal potential. Theories cannot adequately predict the influence of operating parameters on membrane performance. Consequently, new membranes and modules must be experimentally evaluated for each new application. The main objective of this study was to provide fundamental data for designing an operation of nanofiltration under various operating conditions such as transmembrane pressure, cross-flow velocity and initial feed concentration for drinking water and water reuse purposes.The retention rate rises with an increase of the applied pressure, reaches a maximum and then decreases. Such a result is quite different from those usually mentioned in the literature where the retention increases and reaches a plateau when the pressure grows. The singular decrease of the retention rate observed in this study could be explained in terms of a concentration polarization phenomenon. However, since the volumetric flux increased linearly with the pressure and remained close to the pure water flux, it might be thought that such an assumption is not valid in the case of this work. Therefore, another hypothesis has to be provided to explain the variation of the retention with transmembrane pressure. As the size of NH4+ ion (ionic radius=0.148 nm) is lower than that of the pore of membrane (diameter=1 nm), cations can enter the pores where they are partially retained due to surface forces (electrostatic and friction forces). When the pressure increases, these forces remain constant while drag forces increase due to the flux in the pore. At low pressure (∆P < 5 bars), the surface forces are stronger than the drag forces. Therefore, the solute flux remains low while the solvent flux increases with the pressure, leading to an increase in the solute retention. Above a given pressure (≅ 5 bars), the drag forces become higher than the surface forces. Consequently, the retention rate decreases.As can be observed in the obtained results, the retention rate decreased when the feed concentration was increased regardless of the operating pressure. This effect is mainly attributed to the cation shielding of the effective charge of the membrane. This characteristic can be explained by the fact that the electric repulsion becomes less efficient at higher concentration. It has been recognized that the effective charge density of the membrane decreases with an increase in the feed concentration of an ionic solution. Consequently, the retention rate of the co-ion due to charge effect is reduced. It follows that a greater amount of nitrate ions could permeate when feed solutions of higher concentration are applied.The effect of cross-flow velocity on the fluxes is insignificant since the permeate flux depends only on transmembrane pressure. However, the retention performance increases with velocity. The lower the cross-flow velocity, the higher the interaction between the solute and the membrane. Therefore, at low cross-flow rate, the solute amount that enters the membrane pores is high. When the drag forces become stronger than the surface forces, as explained above, the retention sharply decreases. At high cross-flow velocity, the feed circulation transports a large solute amount and therefore, the solute amount that enters the pores is reduced and is less sensitive to operating pressure. In consequence, the sensitivity of the retention to transmembrane pressure is not so marked. It might be thought that for a very high cross-flow velocity, the retention increases and then remains constant.It was demonstrated in this work that nanofiltration can be successfully used to remove nitrates from water. The retention was shown to depend strongly on operating parameters such as feed solution concentration, applied pressure and circulation cross-flow rate. In fact, the retention is mainly determined by the intensity of the solute / membrane interaction. This interaction comes from two main forces: a tangential one due to the feed solute flow (illustrated by the cross-flow velocity effect) and a radial one in the pores due to drag forces (illustrated by the transmembrane pressure effect). Moreover, it was observed that the valence of the associated ions is an important factor that can affect nitrate retention. It can be expected that the optimization of the separation performance will result of the best combination of all these parameters. Therefore, with a view to a future industrial application, it will be necessary to take into consideration the chemical composition of the resource and to adapt the operating conditions to the desired objectives

Bilan Carbone de l'exploitation forestière sur le domaine forestier permanent de Guyane française

International audienceWe propose a set-valued controller with a signum multifunction nested inside another one. We prove that the controller is well posed and achieves robust ultimate boundedness in the presence of mismatched, non-vanishing disturbances. Even more, the selected output can be made arbitrarily small. Also, by applying an implicit/explicit Euler scheme similar to the one introduced by Acary and Brogliato (2010) for matched disturbances, we derive a selection strategy for the discrete-time implementation of the set-valued control law. Simulations demonstrate that the discrete scheme diminishes chattering substantially, compared with a fully explicit method