Disponibilité des résidus agricoles en Inde en vue d’une valorisation énergétique

This study conducted within the academic Chair called New Energy Strategies" in 2010 and 2011 aims at quantifying the share of crop residues that must be set aside for agricultural needs before assessing the availability of agricultural residues for energy production. In a first section, the uses of crop residue uses are surveyed and characterized in terms of agronomic principles for soil conservation and livestock feeding. This understanding of the agricultural needs for residues leads to differentiate several types of residues and several contexts of agricultural and livestock production. For India, the assessment of agricultural needs for crop residues is done by differentiating four main soil types with their specific needs and by estimating how much and which livestock consumes residues. The needs for soil conservation range from 50 to 100% of residues generated, according to crops. The livestock needs for feed are assessed to 294 million tons per year, that is 51% of the total volume of residues generated by crop cultivation.Ce travail réalisé dans le cadre de la Chaire "Nouvelles Stratégies Energétiques" en 2010 et 2011, cherche à quantifier la part des résidus agricoles qui devrait être réservée aux besoins agricoles avant d'estimer la disponibilité des résidus agricoles pour une valorisation énergétique. Dans une première partie, les usages des résidus de culture sont recensés et caractérisés en termes de principes agronomiques pour la conservation des sols et l'alimentation du cheptel. Cette compréhension des besoins agricoles en résidus conduit à bien distinguer différents types de résidus et différents contextes de production agricole et d'élevage. Pour l'ensemble de l'Inde, l'évaluation des besoins agricoles en résidus de culture est réalisée en y distinguant 4 principaux types de sols avec leurs besoins spécifiques et en y estimant la taille et composition du cheptel consommateur de résidus. Les besoins en matière de conservation des sols sont compris dans un intervalle allant de 50% à 100% des résidus générés selon la culture. Les besoins en matière d’alimentation animale sont évalués à 294 millions de tonnes par an soit 51% du volume total de résidus générés par les cultures

Design optimization and optimal control for hybrid vehicles

International audienceIn the context of growing environmental concerns, hybrid-electric vehicles appear to be one of the most promising technologies for reducing fuel consumption and pollutant emissions. This paper presents a parametric study focused on variations of the size of the powertrain components, and optimization of the power split between the engine and electric motor with respect to fuel consumption. To take into account the ability of the engine to be turned off, and the energy consumed to start the engine, we consider a second state to represent the engine: this state permits to obtain a more realistic engine model than it is usually done. Results are obtained for a prescribed vehicle cycle thanks to a dynamic programming algorithm based on a reduced model, and furnish the optimal power repartition at each time step regarding fuel consumption under constraints on the battery state of charge, and may then be used to determine the best components of a given powertrain. To control the energy sources in real driving conditions, when the future is unknown , a real-time control strategy is used: the Equivalent Consumption Minimization Strategy (ECMS). In this strategy, the battery is being considered as an auxiliary reversible fuel reservoir, using a scaling parameter which can be deduced from dynamic programming results. Offline optimization results and ECMS are compared for a realistic hybrid vehicle application

Un processus formel d'intégration de politiques de contrôle d'accès dans les systèmes d'information

Security is a key aspect in information systems (IS) development. One cannot build a bank IS without security in mind. In medical IS, security is one of the most important features of the software. Access control is one of many security aspects of an IS. It defines permitted or forbidden execution of system's actions by an user. Between the conception of an access control policy and its effective deployment on an IS, several steps can introduce unacceptable errors. Using formal methods may be an answer to reduce errors during the modeling of access control policies. Using the process algebra EB[superscript 3], one can formally model IS. Its extension, EB[superscript 3]SEC, was created in order to model access control policies. The ASTD notation combines Harel's Statecharts and EB[superscript 3] operators into a graphical and formal notation that can be used in order to model IS. However, both methods lack tools allowing a designer to prove or verify security properties in order to validate an access control policy. Furthermore, the implementation of an access control policy must correspond to its abstract specification. This thesis defines translation rules from EB[superscript 3] to ASTD, from ASTD to Event-B and from ASTD to B. It also introduces a formal architecture expressed using the B notation in order to enforce a policy over an IS. This modeling of access control policies in B can be used in order to prove properties, thanks to the B prover, but also to verify properties using ProB, a model checker for B. Finally, a refinement strategy for the access control policy into an implementation is proposed. B refinements are proved, this ensures that the implementation corresponds to the initial model of the access control policy

Design Optimization and Optimal Control for Hybrid Vehicles

International audienceGrowing environmental and global crude oil supplies concerns are stimulating research on new vehicle technologies. Hybrid-electric vehicles appear to be one of the most promising technologies for reducing fuel consumption and pollutant emissions. Different types of hybrid-electric powertrains exist: from the mild-hybrid vehicle, equipped with a small electric motor, to the combined hybrid like the Toyota prius. This paper presents a parametric study focused on variations of the size of the powertrain components , and optimization of the power split between the engine and electric motor with respect to fuel consumption. To perform this optimization on a prescribed driving cycle (for instance, the New European Driving Cycle), a dynamic programming algorithm based on a reduced model is implemented. This simplified model allows a fast optimization with a fine parameterization of the controller: it furnishes the optimal power repartition at each time step regarding fuel consumption under constraints on the battery state of charge. The obtained results may be used to determine the best components of a given powertrain, for a prescribed vehicle cycle. The optimal split obtained thanks to dynamic programming algorithm can not be used directly on a vehicle as a real time control law, as the future can not be known in advance in normal driving conditions. To overcome this difficulty, we implement, as a real-time strategy, the Equivalent Consumption Minimization Strategy (ECMS): the battery being considered as an auxiliary reversible fuel reservoir, an instantaneous minimization of ECMS is performed. This control law is inferred from Pontryagin's Minimum Principle, where the Lagrange multiplier can be deduced from previous optimization results on given driving cycles. Offline optimization results and real-time control laws are compared for a realistic hybrid vehicle application. 2

12a Bienal Internacional de Arquitetura de São Paulo

Primer premiPostprint (published version

Influence of Language on Colour Perception: A Simulationist Explanation

“How can perception be altered by language?” is the fundamental question of this article. Indeed, various studies have pointed out the influence of colour-related knowledge on object and colour perception, evoked by linguistic stimuli. Here the relevance of the simulationist approach is assumed in order to explain this influence, where the understanding of colour-related words or sentences involves a process of colour simulation that is supported by a neuronal network partially similar to the network involved in colour perception. Consequently, colour-related knowledge and colour perception can interact through a process of pattern interference. In support of this idea, studies are discussed showing priming effects between colour simulation and colour perception, but two limitations are also raised. Firstly, these works all used between-category colour discrimination tasks that allow the intervention of lexical processes that can also explain priming. Secondly, these works control the congruency link between prime and target at the level of ‘colour category’, and no demonstration is made of an influence at the level of specific hues. Consequently, the simulationist view of language/perception interactions seems an interesting way to thinking but more experimens are needed in order to overcome some limitations

Glucose-derived spiro-isoxazolines are anti-hyperglycemic agents against type 2 diabetes through glycogen phosphorylase inhibition

International audienceGlycogen phosphorylase (GP) is a target for the treatment of hyperglycaemia in the context of type 2 diabetes. This enzyme is responsible for the depolymerization of glycogen into glucose thereby affecting the levels of glucose in the blood stream. Twelve new d-glucopyranosylidene-spiro-isoxazolines have been prepared from O-peracylated exo-D-glucals by regio- and stereoselective 1,3-dipolar cycloaddition of nitrile oxides generated in situ by treatment of the corresponding oximes with bleach. This mild and direct procedure appeared to be applicable to a broad range of substrates. The corresponding O-unprotected spiro-isoxazolines were evaluated as glycogen phosphorylase (GP) inhibitors and exhibited IC50 values ranging from 1 to 800 μM. Selected inhibitors were further evaluated in vitro using rat and human hepatocytes and exhibited significant inhibitory properties in the primary cell culture. Interestingly, when tested with human hepatocytes, the tetra-O-acetylated spiro-isoxazoline bearing a 2-naphthyl residue showed a much lower IC50 value (2.5 μM), compared to that of the O-unprotected analog (19.95 μM). The most promising compounds were investigated in Zucker fa/fa rat model in acute and sub-chronic assays and decreased hepatic glucose production, which is known to be elevated in type 2 diabetes. This indicates that glucose-based spiro-isoxazolines can be considered as anti-hyperglycemic agents in the context of type 2 diabetes