Renewable Electricity Potentials in France: A Long Term Perspective

AbstractRenewable energy sources play a role in providing energy services in a sustainable manner. In this paper, we review and estimate the renewable electricity potentials in France in a long term perspective, considering technical as well as social acceptability factors. Previous assessment studies are reviewed, and specific evaluations are conducted to estimate both the solar electricity potential on residential rooftops and the wind electricity potential in likely-developable areas. Potential effects on the grid power balance are examined for typical winter and summer days based on historical data sets. France has the resources to produce a large portion of its annual final electricity consumption with renewable energy. However, further analysis is needed to evaluate more in depth the influence of limiting factors such as the variability of certain resources, the distribution and transmission constraints, and the potential usage conflicts

Effect of surface preparation on the corrosion of austenitic stainless steel 304L in high temperature steam and simulated PWR primary water

The corrosion behavior of 304L grade stainless steel (SS) in high-temperature steam and in a simulated Pressurized Water Reactor (PWR) is studied. The goal was to characterize the nature of the oxide coating generated during 500 h exposure of samples in a 400 °C steam (200 bar) or a 340 °C simulated PWR. Accelerating the effect of the steam environment as well as the influence of surface preparation have been studied. Two initial sample surfaces were used: mechanical polishing and finishing grinding. Oxide coatings were investigated using TEM imaging coupled with EELS spectroscopy and R – SIMS (Secondary Ion Mass Spectroscopy)

On Dwork's p-adic formal congruences theorem and hypergeometric mirror maps

International audienceUsing Dwork's theory, we prove a broad generalisation of his famous p-adic formal congruences theorem. This enables us to prove certain p-adic congruences for the generalized hypergeometric series with rational parameters; in particular, they hold for any prime number p and not only for almost all primes. Along the way, using Christol's functions, we provide an explicit formula for the ''Eisenstein constant'' of any globally bounded hypergeometric series with rational parameters. As an application of these results, we obtain an arithmetic statement of a new type concerning the integrality of Taylor coefficients of the associated mirror maps. It essentially contains all the similar univariate integrality results in the litterature

Passive flow control study in a convoluted intake using Stereo Particle Image Velocimetry

The ability of vortex generators (VG) to reduce the unsteady distortion at the exit plane of an S-duct (AIP) is investigated. The 3 components of the velocity at the AIP were measured using a Stereo Particle Velocimetry system with high spatial resolution. This enabled an assessment of the synchronous swirl distortion at the duct exit. A total of nine VG cases have been investigated with a systematic variation of key design variables. Overall the VGs change the duct secondary flows and separation and are able to substantially restructure the flow field at the AIP. The pressure distortion could be reduced up to 50% and a reduction in pressure loss of 30% was achieved for the mean flow field. The VGs have a substantial influence on the unsteadiness of the flow field with a reduction in peak swirl unsteadiness of 61% and an overall reduction of unsteady swirl distortion of 67%. They also suppress the primary unsteady flow switching mechanism of the datum configuration which is associated with the oscillation of bulk and twin swirl regimes. Consequently, extreme events which leads to high swirl intensity are suppressed which lower by 45% the maximum swirl intensity for the VG cases

Caractérisation de matériaux électrooptiques

National audienceLe problème posé est la caractérisation d'un matériau disponible en très petite quantité. Nous utilisons les propriétés d'une cavité électromagnétique. Nous mesurons la fréquence de résonance de cette structure en présence et en absence de l'échantillon dont nous cherchons la constante diélectrique

Analyse économique du marché du raisin en Champagne en l'absence de régulation

The limited area for producing grapes of champagne and the separated vertical structure where high reputation brands own little of the land induce steadily growing prices of the raw material. Market foreclosure and concentration both upwards (production cooperatives) and downwards (brands) will be the consequence a prohibited regulation of the market for grapes that will injure consumers welfare both on quality segmentation and product prices.Dans un contexte où le potentiel de commercialisation de l'Appellation d'Origine Contrôlée Champagne continue à croître, une absence de régulation du marché intermédiaire entre vignoble et négoce va conduire à la poursuite de l'augmentation des prix de raisin, la fermeture progressive du marché et à un double mouvement de concentration au détriment du consommateur : quelques très grandes marques en aval et quelques très grandes coopératives en amont. Cet exemple repose la question de la légitimité de l'intervention interprofessionnelle sur les prix intermédiaire

Using lasers for cleaning ceramic and plaster patrimonial objects

International audienceTraditional cleaning techniques (sandblasting, chemical, ...) turn out to be ineffective or damaging on some ceramics and plaster objects. It's especially true on outdoor ceramics covered with black crust or indoor biscuits wares and plasters exposed to dust and repeated handling. The use of lasers to remove dirt, such as for stone, has then been considered. This paper study the behavior of these materials under the impact of different type of lasers irradiation (Nd:YAG first and third harmonic, excimer,...). According to the type of dirt and underlying material, the effectiveness of cleaning depends on the laser wavelength and its energy density. The results are satisfactory with no damage and no coloration change on plaster cleaning by Nd:YAG third harmoni

Analyse économique du marché du raisin en Champagne en l'absence de régulation

Dans un contexte où le potentiel de commercialisation de l'Appellation d'Origine Contrôlée Champagne continue à croître, une absence de régulation du marché intermédiaire entre vignoble et négoce va conduire à la poursuite de l'augmentation des prix de raisin, la fermeture progressive du marché et à un double mouvement de concentration au détriment du consommateur : quelques très grandes marques en aval et quelques très grandes coopératives en amont. Cet exemple repose la question de la légitimité de l'intervention interprofessionnelle sur les prix intermédiaires

Concurrence internationale dans le secteur viticole : quel avenir au modèle d’appellation d’origine contrôlée ?

Le modèle français des appellations d'origine contrôlée (AOC) viticoles a prouvé qu'il pouvait favoriser une offre particulièrement variée et maintenir une population importante de viticulteurs, avec des effets positifs sur l'emploi et l'aménagement du territoire. Les conditions de succès économique de ce modèle sur le long terme sont néanmoins exigeantes. Deux causes majeures profondément liées permettent d'expliquer les limites rencontrées aujourd'hui par ce système, notamment dans le secteur des AOC génériques : - l'organisation des marchés des vins entre vignerons et négociants est souvent déficiente. Les fortes variations des cours qui en résultent rendent difficile la mise en place de contrats incitatifs garantissant aux metteurs en marché des approvisionnements en vins programmables en quantité et en qualité ; - la structure financière des firmes qui sont devenues les partenaires régionaux des vignobles d'AOC pour la mise en marché est peu propice au développement de stratégies de création de marques et de réseaux de distribution propres. Après une présentation détaillée de ce diagnostic, des propositions opérationnelles sont formulées pour une nouvelle organisation économique favorisant la participation des AOC à des stratégies concertées avec le négoce. Une telle évolution devrait améliorer les capacités de la filière viticole européenne à maintenir et à développer sa position au niveau international.

Natural Language Processing for aviation safety reports: from classification to interactive analysis

International audienceIn this paper we describe the different NLP techniques designed and used in collaboration between the CLLE-ERSS research laboratory and the CFH / Safety Data company to manage and analyse aviation incident reports. These reports are written every time anything abnormal occurs during a civil air flight. Although most of them relate routine problems, they are a valuable source of information about possible sources of greater danger. These texts are written in plain language, show a wide range of linguistic variation (telegraphic style overcrowded by acronyms or standard prose) and exist in different languages, even for a single company/country (although our main focus is on English and French). In addition to their variety, their sheer quantity (e.g. 600/month for a large airline company) clearly requires the use of advanced NLP and text mining techniques in order to extract useful information from them. Although this context and objectives seem to indicate that standard NLP techniques can be applied in a straightforward manner, innovative techniques are required to handle the specifics of aviation report text and the complex classification systems. We present several tools that aim at a better access to this data (classification and information retrieval), and help aviation safety experts in their analyses (data/text mining and interactive analysis). Some of these tools are currently in test or in use both at the national and international levels, by airline companies as well as by regulation authorities (DGAC, EASA , ICAO)