WorldWideScience

Sample records for batiment des modeles

  1. Accessibilite des batiments publics aux personnes handicapees

    CERN Document Server

    Colloca, C

    2003-01-01

    Selon les législations suisse et franèaise, les lieux de travail ainsi que les bâtiments recevant du public, doivent être aménagés en tenant compte de la présence de travailleurs et de public handicapés et de manière à favoriser leur autonomie. Les dispositions adoptées pour les accès, les portes, les dégagements et les ascenseurs desservant les postes de travail ou à vocation conviviale, et les locaux annexes tels que locaux sanitaires, locaux de restauration, parcs de stationnement, doivent permettre l'accès et l'évacuation des personnes handicapées, notamment celles circulant en fauteuil roulant.

  2. Reduction of thermal models of buildings: improvement of techniques using meteorological influence models; Reduction de modeles thermiques de batiments: amelioration des techniques par modelisation des sollicitations meteorologiques

    Energy Technology Data Exchange (ETDEWEB)

    Dautin, S.

    1997-04-01

    This work concerns the modeling of thermal phenomena inside buildings for the evaluation of energy exploitation costs of thermal installations and for the modeling of thermal and aeraulic transient phenomena. This thesis comprises 7 chapters dealing with: (1) the thermal phenomena inside buildings and the CLIM2000 calculation code, (2) the ETNA and GENEC experimental cells and their modeling, (3) the techniques of model reduction tested (Marshall`s truncature, Michailesco aggregation method and Moore truncature) with their algorithms and their encoding in the MATRED software, (4) the application of model reduction methods to the GENEC and ETNA cells and to a medium size dual-zone building, (5) the modeling of meteorological influences classically applied to buildings (external temperature and solar flux), (6) the analytical expression of these modeled meteorological influences. The last chapter presents the results of these improved methods on the GENEC and ETNA cells and on a lower inertia building. These new methods are compared to classical methods. (J.S.) 69 refs.

  3. Modeling of delayed strains of concrete under biaxial loadings. Application to the reactor containment of nuclear power plants; Modelisation des deformations differees du beton sous sollicitations biaxiales. application aux enceintes de confinement de batiments reacteurs des centrales nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Benboudjema, F

    2002-12-15

    The prediction of delayed strains is of crucial importance for durability and long-term serviceability of concrete structures (bridges, containment vessels of nuclear power plants, etc.). Indeed, creep and shrinkage cause cracking, losses of pre-stress and redistribution of stresses, and also, rarely, the ruin of the structure. The objective of this work is to develop numerical tools, able to predict the long-term behavior of concrete structures. Thus, a new hydro mechanical model is developed, including the description of drying, shrinkage, creep and cracking phenomena for concrete as a non-saturated porous medium. The modeling of drying shrinkage is based on an unified approach of creep and shrinkage. Basic and drying creep models are based on relevant chemo-physical mechanisms, which occur at different scales of the cement paste. The basic creep is explicitly related to the micro-diffusion of the adsorbed water between inter-hydrates and intra-hydrates and the capillary pores, and the sliding of the C-S-H gel at the nano-porosity level. The drying creep is induced by the micro-diffusion of the adsorbed water at different scales of the porosity, under the simultaneous effects of drying and mechanical loadings. Drying shrinkage is, therefore, assumed to result from the elastic and delayed response of the solid skeleton, submitted to both capillary and disjoining pressures. Furthermore, the cracking behavior of concrete is described by an orthotropic elastoplastic damage model. The coupling between all these phenomena is performed by using effective stresses which account for both external applied stresses and pore pressures. This model has been incorporated into a finite element code. The analysis of the long-term behavior is also performed on concrete specimens and prestressed concrete structures submitted to simultaneous drying and mechanical loadings. (author)

  4. Modeling and experimental study of heat transfer in innovate building components for industrial production; Modelisation et etude experimentale des echanges de chaleur dans des composants innovants de batiment industriels

    Energy Technology Data Exchange (ETDEWEB)

    Lacena-Neildez, A.

    2000-05-15

    The main objective of the thesis is the study of a new roof thermal behaviour with the thermal transfer by radiation and convection in order to propose an alternative to the mechanical air-conditioning in the overseas islands, and to determine the way of improving the energy performance. Two fundamental results were obtained. First, the coating has a great importance in relation with the radiative properties. Secondly, air channel geometries can complete insufficient coatings in their cooling purpose. In this thesis, both experimental and modelling analyses were carried out. A solar simulator was used for the experiment to carry out a comparative study of prototypes. A performance indicator was defined; it is the eliminated flux, because the temperature is not sufficient to describe the heat exchange. At the same time, the radiative properties of coatings were measured and a characterisation of paints allows to start a new research of innovative infrared reflective paints. A mono-dimensional model was developed describing thermal exchanges in an air channel component. A sensibility study was carried out which allows to determine the main parameters. The experimental study validated the model in rear flux, more realistic than stagnation. Finally, the feasibility of this new steel component was concluded by a technical-economical study. (author)

  5. Numerical modelling in building thermo-aeraulics: from CFD modelling to an hybrid finite volume / zonal approach; Modelisation numerique de la thermoaeraulique du batiment: des modeles CFD a une approche hybride volumes finis / zonale

    Energy Technology Data Exchange (ETDEWEB)

    Bellivier, A.

    2004-05-15

    For 3D modelling of thermo-aeraulics in building using field codes, it is necessary to reduce the computing time in order to model increasingly larger volumes. The solution suggested in this study is to couple two modelling: a zonal approach and a CFD approach. The first part of the work that was carried out is the setting of a simplified CFD modelling. We propose rules for use of coarse grids, a constant effective viscosity law and adapted coefficients for heat exchange in the framework of building thermo-aeraulics. The second part of this work concerns the creation of fluid Macro-Elements and their coupling with a calculation of CFD finite volume type. Depending on the boundary conditions of the problem, a local description of the driving flow is proposed via the installation and use of semi-empirical evolution laws. The Macro-Elements is then inserted in CFD computation: the values of velocity calculated by the evolution laws are imposed on the CFD cells corresponding to the Macro-Element. We use these two approaches on five cases representative of thermo-aeraulics in buildings. The results are compared with experimental data and with traditional RANS simulations. We highlight the significant gain of time that our approach allows while preserving a good quality of numerical results. (author)

  6. Automatic generation of zonal models to study air movement and temperature distribution in buildings; Generation automatique de modeles zonaux pour l'etude du comportement thermo-aeraulique des batiments

    Energy Technology Data Exchange (ETDEWEB)

    Musy, M.

    1999-07-01

    This study consists in showing that it is possible to automatically build zonal models that allow to predict air movement, temperature distribution and air quality in the whole building. Zonal models are based on a rough partitioning of the rooms. It is an intermediate approach between one-node models and CFD models. One-node models consider an homogeneous temperature in each room, and for that reason, do not permit to predict the thermal comfort in a room whereas CFD models require a great amount of simulation time To achieve this aim, the zonal model was entirely reformulated as the connection of small sets of equations. The equations describe, either the state of a sub-zone of the partitioning (such sets of equations are called 'cells'), or mass and energy transfers that occur between two sub-zones (then, they are called 'interfaces'). There are various 'cells' and 'interfaces' to represent different air flows that occur in buildings. They all have been translated into SPARK objects that form a model library. Building a simulation consists in choosing the appropriate models to represent the rooms, and connecting them. The last stage has been automated. So, the only thing the user has to do is to give the partitioning and to choose the models to be implemented. The resulting set of equations is solved iteratively with SPARK. Results of simulations in 3D-rooms are presented and compared with experimental data. examples of zonal models are also given. They are applied to the study of a group of two rooms, a building, and a room the geometry of which is complex. (author)

  7. Hygro-thermo-aeraulic modeling of multi-zone buildings. Proposal of a strategy for the resolution of the coupled system; Modelisation hygro-thermo-aeraulique des batiments multizones. Proposition d'une strategie de resolution du systeme couple

    Energy Technology Data Exchange (ETDEWEB)

    Woloszyn-Vallon, M.

    1999-11-01

    The two criteria necessary for the thermal design of buildings - user's comfort and energy efficiency - can lead to contradictory recommendations. In the analyses of both aspects, air moisture content can be an important factor. However, in most existing computer software, moisture is either neglected or represented in a very simplified way. Often only the airborne moisture is represented and the interaction with hygroscopic materials is neglected. We are interested hare in the construction of a comprehensive and reliable tool, able to analyse moisture propagation in a multizone space. All physical phenomena important for correct description of the reality should be integrated. The numerical reliability of the tool should also be ensured in order to enable its industrial use. The results of this work will be applied to CLIM2000, a modular building simulation environment developed by EDF (French Electricity Company). Moisture propagation in a multizone space is a complex phenomenon, especially if the interaction with energy and airflow is represented. However, at the scale of a complete building, four main elements can be distinguished: airborne moisture transport; vapour condensation on cold surface and in the air volume; vapour absorption by hygroscopic materials; sources of vapour (metabolism, housekeeping). In respect to the hypothesis of a multizone model, a consistent set of mathematical models is elaborated. Full interaction among moisture, energy and airflow is represented, enabling simulations of the integrated moisture-energy-airflow behaviour of a multizone building. In order to verify the ability of the proposed model to represent the real situations, its predictions are compared to experimental data. The data were obtained in a fully furnished test house belonging to Building Research Establishment (UK). This experimentation permits analysis of moisture spread in the house and especially the importance of the airborne transport and the influence of

  8. The photovoltaic and the buildings architecture design; Le photovoltaique et la conception architecturale des batiments

    Energy Technology Data Exchange (ETDEWEB)

    Fleuret, J.L. [Conseil Regional Rhone-Alpes (France); Juquois, F.; Beutin, Ph. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France); Jautard, Y. [Office du Tourisme d' Ales, 30 (France); Fromont, R.; Detry, N. [Auberge Royale des Pauvres (Italy); Ferrier, J. [Total 92 - Courbevoie (France); Prignot, I. [Association de Promotion des Energies Renouvelables Wallonie, Bruxelles (APERe) (Belgium); Pellegrin, F. [Union National des Architectes (UNSFA), 75 - Paris (France); Greipmeier, K. [Zentrum fur Rationelle Energieanwendung und Umwelt Gmbh ZREU (Germany); Jedlizka, M.; Lenoire, D. [Cler/ Hespul, 69 - Villeurbanne (France); Mansot, J. [Ademe, 69 - Lyon (France)

    2003-07-01

    This second conference of the thematic work package ''building integrated photovoltaic'' was held exclusively in French. Primarily aimed at architects and technical services of local municipalities, this conference was opened by Jean-Loup FLEURET, Vice President of the Regional Government (Region Rhone Alpes). Following this opening speech, Didier LENOIR, President of the CLER, discussed the current energy context, followed by Fabrice JUQUOIS of the ADEME Renewable Energies Department who presented the French photovoltaic market. Alain GUIAVARCH, from the Ecole des Mines, Paris presented their new software for simulating the thermal impact of photovoltaic on buildings. The first Round Table gave architects the opportunity to discuss their past and future projects, whilst a series of images illustrating their projects were projected. Alain BANSAC, Vice-President of the National Architects Union (UNSFA) summarised the round table. The afternoon session of this conference was opened by PREDAC partner Klaus GREIPMEIER (ZREU) with a stimulating overview of the German BIPV market. Alain RICAUD from Cythelia then presented their software for sizing photovoltaic for building integration. The second Round Table gave the microphone to system owners - from private individuals to local councils and special use buildings, demonstrating the varied motivations and needs of final-end Clients. Marc JEDLICZKA (CLER Vice-president and Hespul General Director) and Philippe BEUTIN (ADEME RES Department Head) summarised the second round tables, before Jose MANSOT, the Regional ADEME Delegate, closed the day. (author)

  9. Thermal and airflow prediction in buildings by associating models with different levels of details within an object-oriented simulation environment; Prediction des performances thermo-aerauliques des batiments par association de modeles de differents niveaux de finesse au sein d'un environnement oriente objet

    Energy Technology Data Exchange (ETDEWEB)

    Mora, L.

    2003-09-01

    The design of innovative HVAC systems, as well as the evaluation of the comfort of occupants requires a detailed estimation of airflows and heat transfers within building zones. Zonal and CFD methods can in principal provide such details, but in practice they are difficult to apply to study a whole building over long periods of time. In this study, we propose a new simulation platform based on the object oriented simulation environment SPARK to treat most of building zones using the nodal approach. This modeling method considers each zone as a fully and instantaneously well mixed volume. In this case, each zone can be characterized by a unique computational node where temperature, pressure and concentration are determined. Then, some specific rooms are studied with more details. In order to see the impact of these details on the entire building model, we propose different coupling methods depending on models associations between the nodal approach, and zonal or CFD room models. After a brief presentation of the different modeling methods used in this study, we attempt to demonstrate the interest to use one method instead of another depending on the room characteristics or the modeler's objectives. We then present the developed platform in which we solve both nodal and zonal models, and we couple detailed room models with the first method. Finally, a few applications demonstrate some capabilities of the developed platform to not only adjust the level of detail for each room model, but also propose new ways of research. In fact, the last application shows a new coupling method between zonal and CFD methods. In this approach, the first method acquires the airflow structure from results obtained using a CFD model in the room. Consequently, the developed platform has numerous applications, to study the dynamics of heat and mass transfers in buildings as well as in their immediate surroundings. (author)

  10. Siloette, Siloe mock-up; Siloette, modele nucleaire de siloe

    Energy Technology Data Exchange (ETDEWEB)

    Delcroix, V.; Jeanne, G.; Mitault, G.; Schulhof, P. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    Siloette is the Siloe mock-up. The main installations are described: various tanks, building, auxiliaries, control systems... Precis ions are given about precautions taken for using spent fuel elements. (authors) [French] Siloette est le modele nucleaire de SILOE. On decrit ses diverses installations: bassins, batiments, auxiliaires, controle... Des precisions sont donnees sur les precautions prises pour y utiliser des elements uses. (auteurs)

  11. Use of air/ground heat exchangers for heating and cooling of buildings - in-situ measurements, analytical modeling, numerical simulation and system analysis[Dissertation 3357]; Utilisation des echangeurs air/sol pour le chauffage et le rafraichissement des batiments. Mesures in situ, modelisation analytique, simulation numerique et analyse systemique

    Energy Technology Data Exchange (ETDEWEB)

    Hollmuller, P.

    2002-07-01

    In this thesis, physical properties and practical implementation of air/ground heat exchangers were studied. These exchangers consist in ducts placed in the upper ground layer (up to a depth of several meters). Air is circulated through the ducts, with heat transfer from and to the surrounding earth/sand/gravel material, with heat diffusion (conductive and capacitive effects) through this material. Air/ground heat exchangers are used to preheat or cool the air needed by the ventilation system of a building (open loop systems), or to heat up or cool the air in a greenhouse (closed loop systems). The reported study consisted in: (i) case studies of built examples, by detailed measuring and monitoring and data analysis. (ii) modeling the basic system. (iii) solving the basic equations both numerically (by computerized simulation) and analytically. (iv) identifying the basic features of these systems. (v) establishing recommendations for the practical implementation, especially in what regards sizing. It turned out that daily and seasonal heat storage/delivery by means of an air/ground heat exchanger have to be considered separately, with ad hoc rules of thumb each. Depending on parameter values a phase shift by as much as half the period may even be observed, with very little damping of the temperature oscillation. In Switzerland the main relevance for these systems is for improving thermal comfort in buildings in the summer time when outdoor temperature is higher than 26 {sup o}C, and for damping the amplitude of day/night temperature variations in horticultural greenhouses. The work carried out can be considered as of basic relevance for all applications of the systems studied.

  12. Modelisation des systemes geothermiques a boucles horizontales pour chauffer les batiments et prevenir la fonte du pergelisol

    Science.gov (United States)

    Fontaine, Pier-Olivier

    2011-12-01

    In northern regions, due to climate change, the increase in the annual mean air temperature increases the depth at which the permanently frozen ground (permafrost) is located. This melting causes soil instability and therefore, the instability of the buildings and transport structures above it. These regions are highly dependent on fossil fuels as a large quantity is used to heat buildings and generate electricity. A solution to these problems is presented in this memoir. It involves using a heat exchanger coupled to a horizontal geothermal heat pump for both heating a building and maintaining the integrity of the permafrost beneath it. A new analytical model for horizontal ground heat exchanger based on the finite line source is presented. This model extends to the transient case in the soil and to any desired pipe layout the steady state results for parallel horizontal pipes of Claesson et Dunand (1983). The heat transfer ratio can change along the pipe. The analytical model can not account for the groundwater phase change given the complexity of the phenomenon. When there is no phase change the analytical model is validated by a 3D finite element numerical model. When the phase change is accounted for in the numerical model, for weather data from northern regions, the analytical model still provides good approximations to the ground temperature during the intensive heating season, hence allowing to compute the heat extracted by the ground heat exchanger (GHE). However, summer ground temperature and thaw depth are overestimated by the analytical model, so that the analytical model gives conservative results. A case study using a geoexchange thermal system is presented. It consists in freezing the ground under a building and heat it at the same time. A typical building in Kuujjuaq (northern Canada) is analyzed. The GHE layout follows a spiral pattern characterized globally by 3 parameters : length L, depth D and spacing S. The influence of each parameter on the

  13. Air flows in big cavity, building aeraulics; ecoulements de l`air en grande cavite, aeraulique des batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This workshop day was jointly organized by the French society of thermal engineers (SFT) and the university group of thermal engineers (GUT). This compilation of proceedings comprises 10 papers dealing with: the use of zonal models for the prediction of the temperature field inside buildings; prediction of the natural ventilation air renewing inside a cavity with a single big aperture using a finite-difference code; experimental validation of the EOL-3D code in industrial ventilating; precise numerical modeling of flows inside ventilated or not-ventilated cavities with pollutant species using a finite difference field code; building aeraulics at Electricite de France (EdF): from the basic research to field applications; experimental study of a heavy vertical jet, influence on the thermal comfort inside a air-conditioned room; study of non-isothermal 3-D free jets: comparison of measurement results with field code modeling; natural air-conditioning of accommodations in humid tropical climate; natural ventilating in humid tropical climate, proposition for a method of evaluation of the velocity coefficients; comparison between measurements and calculations concerning the atmosphere of occupied rooms. (J.S.)

  14. Analyse de vuln\\'erabilit\\'e sismique \\`a grande \\'echelle par utilisation des propri\\'et\\'es dynamiques exp\\'erimentales des b\\^atiments

    OpenAIRE

    Michel, Clotaire; Guéguen, Philippe

    2007-01-01

    Two different way of assessing seismic vulnerability are available nowadays: observed or empirical and calculated vulnerability assessment methods. The first methods are based on observed damage after earthquakes correlated with the structural properties of buildings, whereas the second methods are based on numerical models more or less representing the buildings. In both cases, the trouble is the imperfect knowledge of existing buildings. We propose here a new method for estimating the vulne...

  15. MANAGEMENT DES RISQUES GéOTHECHNIQUES PAR LA MéTHODE « AMDEC » DANS L’AMENAGEMENT URBAIN ET LA CONSTRUCTION:DU PDAU AU PROJET DE BATIMENT

    OpenAIRE

    CHERKI, SAAD; HEMAHMI, MOHAMMED RADWANE

    2014-01-01

    Après avoir cadré les risques géotechniques, nous avons abordé l’essentiel des activités relatives du management des risques et son processus général : l’identification, l’évaluation, et l’analyse pour les risques géotechniques dans un milieu urbain ainsi que l’importance de la cartographie pour ce dernier. Aussi, pour manager les risques géotechniques avec plus d’efficacité et d’efficience, nous avons choisi d’utiliser la méthode de gestion des risques l’AMDEC (Analyse des Mod...

  16. Analyse des transferts de chaleur et de masse transitoires dans un arena a l'aide de la methode zonale

    Science.gov (United States)

    Daoud, Ahmed

    Cette these presente les resultats d'une etude sur le mouvement de l'air et les transferts thermiques et massiques dans les arenas en regime transitoire et en 3D. Pour la partie aeraulique, il a ete question de developper un modele base sur la methode zonale qui permet de calculer les debits de l'air (dus a la ventilation et aux gradients de temperature) et de l'humidite entre les differentes zones du batiment et de determiner l'age de l'air dans chacune des zones. Pour la partie thermique, un modele de calcul du rayonnement entre les surfaces interieures du batiment qui a ete couple a TRNSYS afin de calculer sur une base annuelle les charges de chauffage et de refrigeration; ces dernieres tiennent compte des transferts radiatif et convectif, de la chaleur latente due a la condensation de l'humidite sur la glace et du surfacage. Le document presente est constitue de 7 chapitres qui peuvent etre resumes comme suit: Les chapitres 1, 2 et 3 sont consacres respectivement: a l'introduction generale, a la revue bibliographique et a la description du batiment modelise. Le chapitre 4 decrit l'approche developpee et la contribution importante qui y est apportee. Il presente l'utilisation de la methode zonale comme une alternative pratique aux methodes CFD car elle permet de realiser des simulations dynamiques sur une annee avec des temps de simulation tres courts et une precision acceptable. Il s'agit d'une approche intermediaire entre les modeles CFD et les modeles a un noeud d'air (considerant la temperature homogene dans un local). Le chapitre 5 est consacre a la methode de resolution numerique. L'outil de simulation a ete developpe en utilisant l'interface du logiciel TRNSYS: Le type 56 de ce logiciel a ete adopte comme modele energetique tandis que les autres modeles ont ete developpes et programmes en utilisant le logiciel MATLAB. Le chapitre 6 presente les resultats de simulation pour un arena sans faux plafond et avec un faux plafond et les resultats de mesures

  17. Scenarios of high greenhouse gas emission reduction in transports and buildings by 2050; Scenarios de forte reduction des emissions de gaz a effet de serre dans les transports et les batiments a l'horizon 2050

    Energy Technology Data Exchange (ETDEWEB)

    Teissier, O.; Meunier, L. [Commissariat General au Developpement durable (CGDD/SEEIDD), 75 - Paris (France)

    2008-07-01

    The authors report simulations of different environmental policy measures concerning transports and buildings in France. First, they review measures which may entail a reduction of greenhouse gas emissions, and comment their emission reduction potential and their implementation costs. These measures are then ranked, and only those presenting a significant potential and an economically and technologically feasibility are finally considered. Their impact is then simulated by using different models which are adapted to the both sectors and to time ranges. The obtained results are compared to those obtained with a calibrated trend scenario and with a 'factor 4' scenario.

  18. Methods for estimating residential building energy consumption by application of artificial intelligence; Methode d'estimation energetique des batiments d'habitation basee sur l'application de l'intelligence artificielle

    Energy Technology Data Exchange (ETDEWEB)

    Kajl, S.; Roberge, M-A. [Quebec Univ., Ecole de technologie superieure, Montreal, PQ (Canada)

    1999-02-01

    A method for estimating energy requirements in buildings five to twenty-five stories in height using artificial intelligence techniques is proposed. In developing this technique, the pre-requisites specified were rapid execution, the ability to generate a wide range of results, including total energy consumption, power demands, heating and cooling consumption, and accuracy comparable to that of a detailed building energy simulation software. The method proposed encompasses (1) the creation of various databases such as classification of the parameters used in the energy simulation, modelling using the Department of Energy (DOE)-2 software and validation of the DOE-2 models; (2) application of the neural networks inclusive of teaching the neural network and validation of the neural network's learning; (3) designing an energy estimate assessment (EEA) system for residential buildings; and (4) validation of the EEA system. The system has been developed in the MATLAB software environment, specifically for the climate in the Ottawa region. For use under different climatic conditions appropriate adjustments need to be made for the heating and cooling consumption. 12 refs., tabs., figs., 2 appendices.

  19. OPTIMISATION DES APPORTS D'ENERGIES HYBRIDES DANS L'HABITAT ECONOME

    OpenAIRE

    AMARA, SOFIANE

    2014-01-01

    LA FONCTION THERMIQUE D'UN BATIMENT EST L'UNE DES PRINCIPALES FONCTION DE CELUI-CI : IL EST NØCESSAIRE QUE L'ENVIRONNEMENT DE LA CONSTRCTION SOIT MAINTENU POUR SATISFAIRE UN CONFORT THERMIQUE DE L'HABITANT .......

  20. Contribution to the study of hybrid ventilation system effectiveness in office and educational buildings; Contribution a l'etude de l'efficacite des systemes de ventilation hybride dans les batiments du secteur tertiaire

    Energy Technology Data Exchange (ETDEWEB)

    Cron, F.

    2004-06-15

    This study is part of the International Energy Agency Annex 35, 'Hybrid Ventilation in New and Retro-fitted Office Buildings', also called the HybVent Project. It presents the numerical analyses of a number of hybrid ventilation systems and their potential for several buildings in relation to local climate characteristics. The first part of this work reviews the state-of-the-art of existing ventilation systems and details the principles, expectations and features of hybrid ventilation systems. This first section also examines some examples of hybrid systems extracted from the collection of Annex 35 case studies. A comprehensive bibliography of numerical tools available for this type of analysis is given in the second section. The numerical models for building simulation and the object-oriented environment used to develop our simulation tool are presented in this section as well. Two single-zone studies undertaken in this project are reported in the third section. The first study concerns an experimental cell simulation. Numerical results are compared to experimental data to validate the use of the simulation tool developed. The second single-zone study predicts the potential of a specific hybrid ventilation system in a typical classroom, given climatic conditions. Finally, the last section presents a more complete study - a multi-zone study of the Tonga school, an Annex 35 case study located in Sweden. Three rooms were modelled initially to compare numerical results to experimental data and then to analyse the performance of the existing hybrid ventilation system and two other systems. This final study was completed for three European cities with very different climates. The overall analysis of the potential of the hybrid ventilation systems considered and the perspective for future work are outlined in the conclusion. (author)

  1. Space heating in buildings: thermal diagnosis of an industrial building; Chauffage des batiments: bilan thermique d`un batiment industriel

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, R.

    1996-12-31

    The various heat transfer equations used for calculations in thermal diagnosis of an industrial building are reviewed: calculation of the heat losses through walls as a function of building materials, calculation of the energy consumption for heating fresh air (as a function of the air pollution rate in the building), calculation of the total heat losses, the heating energy demand and the annual energy consumption. Data concerning building materials characteristics, insulation and heating loads in the various regions of France, are also presented

  2. Parameterization des modeles tumoral bases sur des maillages des donnees experimentaux.

    OpenAIRE

    Jagiella , Nick

    2012-01-01

    In order to establish a predictive model for in-vivo tumor growth and therapy, a multiscale model has to be set-up and calibrated individually in a stepwise process to a targeted cell type and di erent environments (in-vitro and in-vivo). As a proof of principle we will present the process chain of model construction and parametrization from di erent data sources for the avascular growth of the EMT6/Ro and the SK-MES-1 cell line. In a rst step, a multiscale and individual-based model has been...

  3. Regulation of heating and air-conditioning systems based on human thermal sensation: impact on the energy consumption in buildings; Regulation des systemes de chauffage et de climatisation basee sur la sensation thermique humaine: impact sur la consommation d'energie dans les batiments

    Energy Technology Data Exchange (ETDEWEB)

    Endravadan, M.

    2006-02-15

    This study is based on the adaptive approach. The thermal comfort of an individual depends on indoor conditions that can be controlled. However, changes in activity or clothing adjustments are difficult to control and measure in the field experiments. Behavioural actions undertaken by the occupant to overcome the discomfort could be varying and may have diverse consequences. Sometimes these actions are beneficial to the occupant, although often they lead to disastrous amounts of energy consumption. Hence, it becomes crucial to consider the human behaviour and the thermal inertia of the building. The creation of numerical models is useful to study the coupling between these two components and to evaluate the effects of the behaviour on comfort and the energy. The simulations were conducted using TRNSYS software. A model such as 'Global Behavioural Regulator' (GBR) was created to evaluate the effects of clothing or thermostat adjustments made by the occupant depending on his thermal sensation (PMV). The energy costs of several types of regulators have been compared in various seasons for example, winter and summer using a light and heavy weight building. The heating of a whole-building may not be necessary in temperate climates or during mid-season. However, comfortable working conditions could be assured for the occupants with the use of an individual heating system such as a 'Local Heating System' (LHS). In such a context, it becomes interesting to evaluate the occupant's behaviour in regards to local heating and its effects on comfort and energy consumption. The LHS consists of three radiant panels; therefore, it is important to evaluate the local heat exchanges with precision. Experiments conducted with the manikin were used to validate the infra-red model; whereas experiments with real subjects were studied to understand the occupant behaviour on the LHS as a function of their local thermal sensations. These analyses led to the creation

  4. Energy consumptions in existing buildings; Les consommations d'energie des batiments existants

    Energy Technology Data Exchange (ETDEWEB)

    Nuss, St. [Ecole Nationale Superieure des Arts et Industries de Strasbourg, 78 - Saint-Remy-Les-Chevreuse (France)]|[Costic, 78 - Sainte Remy les Chevreuses (France)

    2002-05-01

    This document presents a sectoral analysis of the energy consumptions in existing French buildings: 1) - residential sector: social buildings, private dwellings; 2) - tertiary sector: office buildings, hotels, commercial buildings, school buildings, hospitals; 3) - industry; 4) - general status. (J.S.)

  5. Certification of the boilers acoustic performance; Certification des performances acoustiques des chaudieres. Confort et performances du batiment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    In order to control the noise pollution, a certification has been implemented on the heating installations. So a meeting has been devoted to this topic to show that the certification initiative will allow to design new systems in regards to the acoustic regulation. The context and the application domain of the new acoustic regulation, the technical aspects, the implementing of new systems and some examples of solutions are presented. (A.L.B.)

  6. Analyse des interactions energetiques entre un arena et son systeme de refrigeration

    Science.gov (United States)

    Seghouani, Lotfi

    La presente these s'inscrit dans le cadre d'un projet strategique sur les arenas finance par le CRSNG (Conseil de Recherche en Sciences Naturelles et en Genie du Canada) qui a pour but principal le developpement d'un outil numerique capable d'estimer et d'optimiser la consommation d'energie dans les arenas et curlings. Notre travail s'inscrit comme une suite a un travail deja realise par DAOUD et coll. (2006, 2007) qui a developpe un modele 3D (AIM) en regime transitoire de l'arena Camilien Houde a Montreal et qui calcule les flux de chaleur a travers l'enveloppe du batiment ainsi que les distributions de temperatures et d'humidite durant une annee meteorologique typique. En particulier, il calcule les flux de chaleur a travers la couche de glace dus a la convection, la radiation et la condensation. Dans un premier temps nous avons developpe un modele de la structure sous la glace (BIM) qui tient compte de sa geometrie 3D, des differentes couches, de l'effet transitoire, des gains de chaleur du sol en dessous et autour de l'arena etudie ainsi que de la temperature d'entree de la saumure dans la dalle de beton. Par la suite le BIM a ete couple le AIM. Dans la deuxieme etape, nous avons developpe un modele du systeme de refrigeration (REFSYS) en regime quasi-permanent pour l'arena etudie sur la base d'une combinaison de relations thermodynamiques, de correlations de transfert de chaleur et de relations elaborees a partir de donnees disponibles dans le catalogue du manufacturier. Enfin le couplage final entre l'AIM +BIM et le REFSYS a ete effectue sous l'interface du logiciel TRNSYS. Plusieurs etudes parametriques on ete entreprises pour evaluer les effets du climat, de la temperature de la saumure, de l'epaisseur de la glace, etc. sur la consommation energetique de l'arena. Aussi, quelques strategies pour diminuer cette consommation ont ete etudiees. Le considerable potentiel de recuperation de chaleur au niveau des condenseurs qui peut reduire l'energie requise par

  7. CFD simulations in the nuclear containment using the DES turbulence models

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Peng [School of Engineering, Sun Yat-Sen University, Guangzhou (China); Chen, Meilan [China Nuclear Power Technology Research Institute, Shenzhen (China); Li, Wanai, E-mail: liwai@mail.sysu.edu.cn [Sino-French Institute of Nuclear Engineering & Technology, Sun Yat-Sen University, Guangzhou (China); Liu, Yulan [School of Engineering, Sun Yat-Sen University, Guangzhou (China); Wang, Biao [Sino-French Institute of Nuclear Engineering & Technology, Sun Yat-Sen University, Guangzhou (China)

    2015-06-15

    Highlights: • The k-ε based DES model is used in the nuclear containment simulation. • The comparison of results between different turbulent models is obtained. • The superiority of DES models is analyzed. • The computational efficiency with the DES turbulence models is explained. - Abstract: Different species of gases would be released into the containment and cause unpredicted disasters during the nuclear severe accidents. It is important to accurately predict the transportation and stratification phenomena of these gas mixtures. CFD simulations of these thermal hydraulic issues in nuclear containment are investigated in this paper. The main work is to study the influence of turbulence model on the calculation of gas transportation and heat transfer. The k-ε based DES and other frequently used turbulence models are used in the steam and helium release simulation in THAI series experiment. This paper will show the superiority of the DES turbulence model in terms of computational efficiency and accuracy with the experimental results, and analyze the necessities of DES model to simulate the large-scale containment flows with both laminar and turbulence regions.

  8. CFD simulations in the nuclear containment using the DES turbulence models

    International Nuclear Information System (INIS)

    Ding, Peng; Chen, Meilan; Li, Wanai; Liu, Yulan; Wang, Biao

    2015-01-01

    Highlights: • The k-ε based DES model is used in the nuclear containment simulation. • The comparison of results between different turbulent models is obtained. • The superiority of DES models is analyzed. • The computational efficiency with the DES turbulence models is explained. - Abstract: Different species of gases would be released into the containment and cause unpredicted disasters during the nuclear severe accidents. It is important to accurately predict the transportation and stratification phenomena of these gas mixtures. CFD simulations of these thermal hydraulic issues in nuclear containment are investigated in this paper. The main work is to study the influence of turbulence model on the calculation of gas transportation and heat transfer. The k-ε based DES and other frequently used turbulence models are used in the steam and helium release simulation in THAI series experiment. This paper will show the superiority of the DES turbulence model in terms of computational efficiency and accuracy with the experimental results, and analyze the necessities of DES model to simulate the large-scale containment flows with both laminar and turbulence regions

  9. Use of DES Modeling for Determining Launch Availability for SLS

    Science.gov (United States)

    Staton, Eric; Cates, Grant; Finn, Ronald; Altino, Karen M.; Burns, K. Lee; Watson, Michael D.

    2014-01-01

    The National Aeronautics and Space Administration (NASA) is developing new capabilities for human and scientific exploration beyond Earth's orbit. This effort includes the Space Shuttle derived Space Launch System (SLS), the Orion Multi-Purpose Crew Vehicle (MPCV), and the Ground Systems Development and Operations (GSDO). There are several requirements and Technical Performance Measures (TPMs) that have been levied by the Exploration Systems Development (ESD) upon the SLS, Orion, and GSDO Programs including an integrated Launch Availability (LA) TPM. The LA TPM is used to drive into the SLS, Orion and GSDO designs a high confidence of successfully launching exploration missions that have narrow Earth departure windows. The LA TPM takes into consideration the reliability of the overall system (SLS, Orion and GSDO), natural environments, likelihood of a failure, and the time required to recover from an anomaly. A challenge with the LA TPM is the interrelationships between SLS, Orion, GSDO and the natural environments during launch countdown and launch delays that makes it impossible to develop an analytical solution for calculating the integrated launch probability. This paper provides an overview of how Discrete Event Simulation (DES) modeling was used to develop the LA TPM, how it was allocated down to the individual programs, and how the LA analysis is being used to inform and drive the SLS, Orion, and GSDO designs to ensure adequate launch availability for future human exploration.

  10. The trade-off between DES and SD in modelling military manpower

    Directory of Open Access Journals (Sweden)

    Nethal K. Jajo

    2015-04-01

    Full Text Available Operations research techniques have been used widely in simulating the dynamics of workforce systems. Discrete Event Simulation (DES and System Dynamics (SD are among the techniques that have been increasingly used in modelling military workforces. In the last five years, DES has seen more interest in modelling both career management and the training pipeline. Two significant reasons for this are discussed in this paper. This article presents some notes in comparing the two techniques in modelling military workforce. The study found that DES is an appealing method in workforce modelling, especially with a small size population, as it more easily accommodates new personnel attributes and prevents the fractionalisation of personnel through the system.

  11. Integration des sciences et de la langue: Creation et experimentation d'un modele pedagogique pour ameliorer l'apprentissage des sciences en milieu francophone minoritaire

    Science.gov (United States)

    Cormier, Marianne

    Les faibles resultats en sciences des eleves du milieu francophone minoritaire, lors d'epreuves au plan national et international, ont interpelle la recherche de solutions. Cette these avait pour but de creer et d'experimenter un modele pedagogique pour l'enseignement des sciences en milieu linguistique minoritaire. En raison de la presence de divers degres de francite chez la clientele scolaire de ce milieu, plusieurs elements langagiers (l'ecriture, la discussion et la lecture) ont ete integres a l'apprentissage scientifique. Nous avions recommande de commencer le processus d'apprentissage avec des elements langagiers plutot informels (redaction dans un journal, discussions en dyades...) pour progresser vers des activites langagieres plus formelles (redaction de rapports ou d'explications scientifiques). En ce qui a trait a l'apprentissage scientifique, le modele preconisait une demarche d'evolution conceptuelle d'inspiration socio-constructiviste tout en s'appuyant fortement sur l'apprentissage experientiel. Lors de l'experimentation du modele, nous voulions savoir si celui-ci provoquait une evolution conceptuelle chez les eleves, et si, simultanement, le vocabulaire scientifique de ces derniers s'enrichissait. Par ailleurs, nous cherchions a comprendre comment les eleves vivaient leurs apprentissages dans le cadre de ce modele pedagogique. Une classe de cinquieme annee de l'ecole de Grande-Digue, dans le Sud-est du Nouveau-Brunswick, a participe a la mise a l'essai du modele en etudiant les marais sales locaux. Lors d'entrevues initiales, nous avons remarque que les connaissances des eleves au sujet des marais sales etaient limitees. En effet, s'ils etaient conscients que les marais etaient des lieux naturels, ils ne pouvaient pas necessairement les decrire avec precision. Nous avons egalement constate que les eleves utilisaient surtout des mots communs (plantes, oiseaux, insectes) pour decrire le marais. Les resultats obtenus indiquent que les eleves ont

  12. Building Maintenance Mechanic. Apprenticeship Training Standards = Mecanicien d'entretien des batiments. Normes de formation en apprentissage.

    Science.gov (United States)

    Ontario Ministry of Skills Development, Toronto.

    These training standards for building maintenance mechanics are intended to be used by apprentice/trainees, instructors, and companies in Ontario, Canada, as a blueprint for training or as a prerequisite for accreditation/certification. The training standards identify skills required for this occupation and its related training program. They are…

  13. European conferences. Integration of renewable energies in buildings; Conferences europeennes. Integration des energies renouvelables dans le batiment

    Energy Technology Data Exchange (ETDEWEB)

    Bal, J.L. [ADEME, Agence de l' Environnement et de la Maitrise de l' Energie, 75 - Paris (France); Letz, T. [Asder, 73 - Saint Alban Leysse (France); Tuille, F. [Observ' er, 75 - Paris (France)] [and others

    2001-07-01

    This document comprises 2 parts. First part is a detailed program of the exhibition with a press dossier which presents the different topics discussed during conferences and round tables, the market of renewable energies, and a list of agencies and companies involved in renewable energies development and products. The second part is the abstracts of the lectures presented during the European conferences on the integration of renewable energies in buildings (solar-thermal and photovoltaic systems, wood fuel and biomass). (J.S.)

  14. 3D CFD computations of trasitional flows using DES and a correlation based transition model

    DEFF Research Database (Denmark)

    Sørensen, Niels N.; Bechmann, Andreas; Zahle, Frederik

    2011-01-01

    The present article describes the application of the correlation based transition model of Menter et al. in combination with the Detached Eddy Simulation (DES) methodology to two cases with large degree of flow separation typically considered difficult to compute. Firstly, the flow is computed over....... Secondly, the flow is computed over a thick airfoil at high angle of attack, in this case the DU-96-W351 is considered. These computations show that a transition model is needed to obtain correct drag predictions at low angle of attack, and that the combination of transition and the DES method improve...

  15. Civil engineering: EDF needs for concrete modelling; Genie civile: analyse des besoins EDF en modelisation du comportement des betons

    Energy Technology Data Exchange (ETDEWEB)

    Didry, O.; Gerard, B.; Bui, D. [Electricite de France (EDF), Direction des Etudes et Recherches, 92 - Clamart (France)

    1997-12-31

    Concrete structures which are encountered at EDF, like all civil engineering structures, age. In order to adapt the maintenance conditions of these structures, particularly to extend their service life, and also to prepare constructions of future structures, tools for predicting the behaviour of these structures in their environment should be available. For EDF the technical risks are high and consequently very appropriate R and D actions are required. In this context the Direction des Etudes et Recherches (DER) has developed a methodology for analysing concrete structure behaviour modelling. This approach has several aims: - making a distinction between the problems which refer to the existing models and those which require R and D; - displaying disciplinary links between different problems encountered on EDF structures (non-linear mechanical, chemical - hydraulic - mechanical coupling, etc); - listing of the existing tools and positioning the DER `Aster` finite element code among them. This document is a state of the art of scientific knowledge intended to shed light on the fields in which one should be involved when there is, on one part a strong requirement on the side of structure operators, and on the other one, the present tools do not allow this requirement to be satisfactorily met. The analysis has been done on 12 scientific subjects: 1) Hydration of concrete at early ages: exothermicity, hardening, autogenous shrinkage; 2) Drying and drying shrinkage; 3) Alkali-silica reaction and bulky stage formation; 4) Long term deterioration by leaching; 5) Ionic diffusion and associated attacks: the chlorides case; 6) Permeability / tightness of concrete; 7) Concretes -nonlinear behaviour and cracking (I): contribution of the plasticity models; 8) Concretes - nonlinear behaviour and cracking (II): contribution of the damage models; 9) Concretes - nonlinear behaviour and cracking (III): the contribution of the probabilistic analysis model; 10) Delayed behaviour of

  16. Applying the Chaboche model for describing the creep deformation behaviour of screwed connections; Die Anwendung des Chaboche-Modells zur Beschreibung des Kriechverformungsverhaltens von Schraubenverbindungen

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H.; Fischer, R.; Maile, K.; Mayer, K.H.

    1998-09-01

    The work reported was to describe the multiaxial deformation and stress conditions in cyclically loaded screw-and-nut joints, using as a basis a viscoplastic model, and to derive from this approach possible ways of revealing the in-service behaviour of components from first damage to failure. For computation of the stresses and damage affecting the screwed joint, the constitutive equations of Chaboche-Nuoailhs have been integrated with the UMAT user subroutine into the ABAQUS FE calculation code. Parallel examinations have been carried out under conditions of creep fatigue at 550 C. The experimental results and the calculated FE results have been compared. (orig./CB) [Deutsch] Ziel dieser Arbeit war es die mehrachsige Verformungs- und Spannungssituation an instationaer belasteten Schrauben-Mutter-Verbindungen auf der Basis eines viskoplastischen Modells zu beschreiben und hieraus entsprechend Moeglichkeiten zur Ermittlung des Schaedigungs- und Versagensverhaltens dieser Bauteile aufzuzeigen. Fuer die Berechnung des Beanspruchungszustandes der Schrauben-Mutter-Verbindung wurden die konstitutiven Gleichungen von Chaboche-Nouailhas als User-Subroutine UMAT in das FE-Programm ABAQUS implementiert. Parallel wurden Versuche an der erwaehnten Verbindung unter Kriechermuedung bei 550 C durchgefuehrt. Die Ergebnisse der Versuche und der FE-Berechnung wurden einander gegenuebergestellt. (orig./MM)

  17. Mathematical modelling of deuterium transport in field lysimeters; Mathematische Modellierung des Deuteriumtransports in Freilandlysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Maloszewski, P.; Klotz, D.; Trimborn, P. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie; Maciejewski, S. [Polish Academy of Sciences, Gdansk (Poland). Inst. of Hydroengineering

    1999-02-01

    The results yielded by the Variable Flow Model (VFDM) permitted determining water flow velocities and degrees of dispersiveness. It transpired that it is not possible to isolate immobile water, which is to say that the available measuring and modelling data permit no conclusion as to whether or not the system contains immobile water. Comparison with the results obtained with the Dispersion Model (DM) showed that the simpler DM model yields tracer concentration curves in the system output that are almost as good as those of the more complicated VFDM model while entailing less work. The two models yield very similar calculations of lysimeter water content. [Deutsch] Die Ergebnisse der Modellierung mit dem Variable-Flow-Modell (VFDM) ermoeglichten die Bestimmung von Wassergeschwindigkeiten des Wassers und Dispersivitaeten. Es wurde dabei festgestellt, dass eine Abtrennung des immobilen Wassers nicht moeglich ist. D.h. es kann nicht auf Grund vorhandener Messdaten und der Modellierung entschieden werden, ob das System immobiles Wasser beinhaltet oder nicht. Ein Vergleich der Ergebnisse nach dem Variable-Flow- und dem Dispersions-Modell (DM) zeigte, dass das einfache Modell DM mit weniger Aufwand fast so gute Tracerkonzentrationskurven im Output aus dem System liefert wie das komplizierte Modell mit VFDM. Die berechneten Wassergehalte der Lysimeter nach beiden Modellierungen sind sehr aehnlich. (orig.)

  18. 3D CFD computations of transitional flows using DES and a correlation based transition model

    DEFF Research Database (Denmark)

    Sørensen, Niels N.

    The report describes the application of the correlation based transition model of of Menter et. al. [1, 2] to the cylinder drag crisis and the stalled flow over an DU-96-W-351 airfoil using the DES methodology. When predicting the flow over airfoils and rotors, the laminar-turbulent transition...... process can be important for the aerodynamic performance. Today, the most widespread approach is to use fully turbulent computations, where the transitional process is ignored and the entire boundary layer on the wings or airfoils is handled by the turbulence model. The correlation based transition model...

  19. Technical Status Review Appraisal of the Suitability of Turbulence Models in Flow Calculations (Revue Technique - L’Evaluation de l’Applicabilite des Modeles de Turbulence dans de Calcul des Ecoulements)

    Science.gov (United States)

    1991-07-01

    Ingenieros Aeronauticos B- 1040 Brussels, Belgium Departansento de Mecanica de Fluidos Plaza del Cardenal Cisneros 3 M. l’ing. G~n~ral B. Monnerie 28040...ADVISORY REPORT 291 -; "TechniCal Status Review Appraisal of the Suitability of Turbulence Models in Flow Calculations (Revue Technique - L’Evaluation de ...IApplicabilitc des Mod~les de Turbulence dans Ic Ca lcul des Ecoulrments) , NORTH ATLANTIC TREATY ORGANIZATION +CWI/ Votmfa wyAfj Best Available Copy

  20. Reduction of Military Vehicle Acquisition Time and Cost through Advanced Modelling and Virtual Simulation (La reduction des couts et des delais d’acquisition des vehicules militaires par la modelisation avancee et la simulation de produit virtuel)

    Science.gov (United States)

    2003-03-01

    technology to support interactive digital styling reviews (Celsnek, 1989), virtual showroom reviews (Smith & Leigh, 2000), and aerodynamic flow simulations...SEINE CEDEX, FRANCE RTO MEETING PROCEEDINGS 89 Reduction of Military Vehicle Acquisition Time and Cost through Advanced Modelling and Virtual Simulation...MEETING PROCEEDINGS 89 Reduction of Military Vehicle Acquisition Time and Cost through Advanced Modelling and Virtual Simulation (La réduction des

  1. Developpement D'un Modele Climatique Regional: Fizr Simulation des Conditions de Janvier de la Cote Ouest Nord Americaine

    Science.gov (United States)

    Goyette, Stephane

    1995-11-01

    Le sujet de cette these concerne la modelisation numerique du climat regional. L'objectif principal de l'exercice est de developper un modele climatique regional ayant les capacites de simuler des phenomenes de meso-echelle spatiale. Notre domaine d'etude se situe sur la Cote Ouest nord americaine. Ce dernier a retenu notre attention a cause de la complexite du relief et de son controle sur le climat. Les raisons qui motivent cette etude sont multiples: d'une part, nous ne pouvons pas augmenter, en pratique, la faible resolution spatiale des modeles de la circulation generale de l'atmosphere (MCG) sans augmenter a outrance les couts d'integration et, d'autre part, la gestion de l'environnement exige de plus en plus de donnees climatiques regionales determinees avec une meilleure resolution spatiale. Jusqu'alors, les MCG constituaient les modeles les plus estimes pour leurs aptitudes a simuler le climat ainsi que les changements climatiques mondiaux. Toutefois, les phenomenes climatiques de fine echelle echappent encore aux MCG a cause de leur faible resolution spatiale. De plus, les repercussions socio-economiques des modifications possibles des climats sont etroitement liees a des phenomenes imperceptibles par les MCG actuels. Afin de circonvenir certains problemes inherents a la resolution, une approche pratique vise a prendre un domaine spatial limite d'un MCG et a y imbriquer un autre modele numerique possedant, lui, un maillage de haute resolution spatiale. Ce processus d'imbrication implique alors une nouvelle simulation numerique. Cette "retro-simulation" est guidee dans le domaine restreint a partir de pieces d'informations fournies par le MCG et forcee par des mecanismes pris en charge uniquement par le modele imbrique. Ainsi, afin de raffiner la precision spatiale des previsions climatiques de grande echelle, nous developpons ici un modele numerique appele FIZR, permettant d'obtenir de l'information climatique regionale valide a la fine echelle spatiale

  2. Modeling nitrate-nitrogen load reduction strategies for the Des Moines River, Iowa using SWAT.

    Science.gov (United States)

    Schilling, Keith E; Wolter, Calvin F

    2009-10-01

    The Des Moines River that drains a watershed of 16,175 km(2) in portions of Iowa and Minnesota is impaired for nitrate-nitrogen (nitrate) due to concentrations that exceed regulatory limits for public water supplies. The Soil Water Assessment Tool (SWAT) model was used to model streamflow and nitrate loads and evaluate a suite of basin-wide changes and targeting configurations to potentially reduce nitrate loads in the river. The SWAT model comprised 173 subbasins and 2,516 hydrologic response units and included point and nonpoint nitrogen sources. The model was calibrated for an 11-year period and three basin-wide and four targeting strategies were evaluated. Results indicated that nonpoint sources accounted for 95% of the total nitrate export. Reduction in fertilizer applications from 170 to 50 kg/ha achieved the 38% reduction in nitrate loads, exceeding the 34% reduction required. In terms of targeting, the most efficient load reductions occurred when fertilizer applications were reduced in subbasins nearest the watershed outlet. The greatest load reduction for the area of land treated was associated with reducing loads from 55 subbasins with the highest nitrate loads, achieving a 14% reduction in nitrate loads achieved by reducing applications on 30% of the land area. SWAT model results provide much needed guidance on how to begin implementing load reduction strategies most efficiently in the Des Moines River watershed.

  3. batiment SHM|SHM building|Control valves on top of a ´cold box´ for the 4K refrigeration system for the LHC |Valves de contrôle sur le dessus de la ´boite froide´ pour le système de refroidissement 4K du LHC

    CERN Multimedia

    Valeriane Duvivier

    2001-01-01

    batiment SHM|SHM building|Control valves on top of a ´cold box´ for the 4K refrigeration system for the LHC |Valves de contrôle sur le dessus de la ´boite froide´ pour le système de refroidissement 4K du LHC

  4. Modeling and simulation of bus assem-bling process using DES/ABS approach

    Directory of Open Access Journals (Sweden)

    Pawel PAWLEWSKI

    2017-03-01

    Full Text Available This paper presents the results of the project, which goal is to analyze the production process capability after reengineering the assembly process due to expansion of a bus production plant. The verification of the designed work organization for the new configuration of workstations on new production hall is necessary. To solve these  problems authors propose a method based on mixing DES (Discrete Event Simulation and ABS (Agent Based Simulation approach. DES is using to model the main process – material flow (buses, ABS is using to model assembling operations of teams of  workers.One of obtained goal is to build a simulation model, which presents the new assembly line in the factory, taking into ac-count the arrangement of workstations and work teams in the new production hall as well as the transport between workstations. Second goal is to present work organization of work teams and division of individual workers’ labor (who belongs to a particular work team and performs operations on buses in a particular workstation in order to determine the best allocation of tasks and the optimum size of individual work teams. Proposed solution enables to determine the effect of assembly interferences on the work of particular work teams and the efficiency of the whole production system, to define the efficiency of the designed assembly lines and proposing changes aimed at the quality improvement of the created conception. 

  5. CONTROLE DE COHERENCE ET DE FAISABILITE DE PROJETS DANS UN SYSTEME DE C.A.O. BATIMENT

    Directory of Open Access Journals (Sweden)

    M BELACHIA

    2001-06-01

    Full Text Available Le contrôle de la cohérence et de la faisabilité est devenu une préoccupation essentielle pour les développeurs de systèmes de C.A.O, car les concepteurs et les utilisateurs ont besoin d’outils pour vérifier la validité de leur conception. Nous supposons qu’une large partie de ce contrôle est intégrée dans les modules techniques. Cependant, plus particulièrement lors de l’étude des phases précoces de conception, il s’avère indispensable d’identifier les causes des dysfonctionnements. Après une analyse des différents types d’anomalies que nous pouvons rencontrer durant le processus de conception pouvant conduire à des incohérences ou des «non faisabilité» d’un projet, nous avons déduit les méthodes appropriées pour informer les utilisateurs à bon escient. Elles sont généralement basées sur des vérifications automatiques et transparentes avec des possibilités de reports de déclenchement des contrôles.

  6. Models of the Strongly Lensed Quasar DES J0408-5354

    Energy Technology Data Exchange (ETDEWEB)

    Agnello, A.; et al.

    2017-02-01

    We present gravitational lens models of the multiply imaged quasar DES J0408-5354, recently discovered in the Dark Energy Survey (DES) footprint, with the aim of interpreting its remarkable quad-like configuration. We first model the DES single-epoch $grizY$ images as a superposition of a lens galaxy and four point-like objects, obtaining spectral energy distributions (SEDs) and relative positions for the objects. Three of the point sources (A,B,D) have SEDs compatible with the discovery quasar spectra, while the faintest point-like image (G2/C) shows significant reddening and a `grey' dimming of $\\approx0.8$mag. In order to understand the lens configuration, we fit different models to the relative positions of A,B,D. Models with just a single deflector predict a fourth image at the location of G2/C but considerably brighter and bluer. The addition of a small satellite galaxy ($R_{\\rm E}\\approx0.2$") in the lens plane near the position of G2/C suppresses the flux of the fourth image and can explain both the reddening and grey dimming. All models predict a main deflector with Einstein radius between $1.7"$ and $2.0",$ velocity dispersion $267-280$km/s and enclosed mass $\\approx 6\\times10^{11}M_{\\odot},$ even though higher resolution imaging data are needed to break residual degeneracies in model parameters. The longest time-delay (B-A) is estimated as $\\approx 85$ (resp. $\\approx125$) days by models with (resp. without) a perturber near G2/C. The configuration and predicted time-delays of J0408-5354 make it an excellent target for follow-up aimed at understanding the source quasar host galaxy and substructure in the lens, and measuring cosmological parameters. We also discuss some lessons learnt from J0408-5354 on lensed quasar finding strategies, due to its chromaticity and morphology.

  7. Modelling Laser Milling of Microcavities for the Manufacturing of DES with Ensembles

    Directory of Open Access Journals (Sweden)

    Pedro Santos

    2014-01-01

    Full Text Available A set of designed experiments, involving the use of a pulsed Nd:YAG laser system milling 316L Stainless Steel, serve to study the laser-milling process of microcavities in the manufacture of drug-eluting stents (DES. Diameter, depth, and volume error are considered to be optimized as functions of the process parameters, which include laser intensity, pulse frequency, and scanning speed. Two different DES shapes are studied that combine semispheres and cylinders. Process inputs and outputs are defined by considering the process parameters that can be changed under industrial conditions and the industrial requirements of this manufacturing process. In total, 162 different conditions are tested in a process that is modeled with the following state-of-the-art data-mining regression techniques: Support Vector Regression, Ensembles, Artificial Neural Networks, Linear Regression, and Nearest Neighbor Regression. Ensemble regression emerged as the most suitable technique for studying this industrial problem. Specifically, Iterated Bagging ensembles with unpruned model trees outperformed the other methods in the tests. This method can predict the geometrical dimensions of the machined microcavities with relative errors related to the main average value in the range of 3 to 23%, which are considered very accurate predictions, in view of the characteristics of this innovative industrial task.

  8. A Designer’s Guide to Human Performance Modelling (La Modelisation des Performances Humaines: Manuel du Concepteur).

    Science.gov (United States)

    1998-12-01

    humaine et de r6seaux de t~ches. Une description de la logique dont HOMER s’inspire (les crit~res de choix des mod~les par exemple), est incluse dans le...REPORT 356 A Designer’s Guide to Human Performance Modelling ( la Modelisation des performances humaines: manuel du concepteur) This Advisory Report has...DEVELOPMENT BP 25, 7 RUE ANCELLE, F-92201 NEUILLY-SUR-SEINE CEDEX, FRANCE AGARD ADVISORY REPORT 356 A Designer’s Guide to Human Performance Modelling ( la

  9. Evaluation des bassins par modélisation intégrée en deux dimensions des transferts techniques, de l'écoulement des fluides, de la genèse et de la migration des hydrocarbures Basin Evaluation by Integrated Two-Dimensional Modeling of Heat Transfer, Fluid Flow, Hydrocarbon Generation, and Migration

    Directory of Open Access Journals (Sweden)

    Chenet P. Y.

    2006-11-01

    Full Text Available Le modèle de bassin exposé dans cet article décrit les phénomènes physiques et chimiques qui contrôlent la formation d'accumulations commerciales, dans le cadre évolutif d'un bassin sédimentaire affecté par la subsidence : transfert de chaleur, compaction et écoulement de l'eau, génèse des hydrocarbures, migration diphasique de l'eau et des hydrocarbures. Le modèle tient compte des variations de conductivité et des phénomènes thermiques transitoires pour reconstituer les paléo-températures. Des validations quantitatives de la reconstitution des paléo-températures et du modèle cinétique de formation des hydrocarbures peuvent être obtenues par comparaison avec les températures actuelles et les données géochimiques. Les écoulements et les surpressions induits par la compaction sont décrits en couplant une loi de compaction avec la loi de Darcy, classique pour les écoulements de l'eau, en ajoutant un critère de fracturation hydraulique naturelle. Ceci permet de modéliser les pressions anormales dans des séquences deltaïques récentes (delta de la Mahakam, comme dans des bassins liés à des rifts anciens (mer du Nord. Une adaptation de la loi de Darcy aux écoulements diphasiques permet de reproduire la migration primaire et la migration secondaire. En particulier, le modèle permet d'étudier le rôle des pressions anormales et l'influence des failles sur la migration et le piégeage. Nos résultats confirment que les modèles de bassins peuvent contribuer à synthétiser les données géologiques, géophysiques et géochimiques dans un schéma cohérent. En précisant l'évaluation pétrolière, ces modèles constituent une des principales voies pour améliorer l'efficacité de l'exploration. The basin model discussed in this paper describes the physical and chemical phenomena that control the formation of commercial accumulations of hydrocarbons in the moving framework of a subsiding sedimentary basin : heat

  10. Calcul du flux thermique a travers la liaison batiment- Sol | Diao ...

    African Journals Online (AJOL)

    In this work, we propose analytical models in two dimensions (2D) for the calculation of the thermal transfers through the connection building and ground in steady, witch we determine the linear thermal coefficient, and dynamic method. The methods used hold parameters geometrical and thermal having a great influence on ...

  11. Hydraulic properties of fracture networks; Analyse des proprietes hydrauliques des reseaux de fractures: discussion des modeles d'ecoulement compatibles avec les principales proprietes geometriques

    Energy Technology Data Exchange (ETDEWEB)

    Dreuzy, J.R. de

    1999-12-15

    Fractured medium are studied in the general framework of oil and water supply and more recently for the underground storage of high level nuclear wastes. As fractures are generally far more permeable than the embedding medium, flow is highly channeled in a complex network of fractures. The complexity of the network comes from the broad distributions of fracture length and permeability at the fracture scale and appears through the increase of the equivalent permeability at the network scale. The goal of this thesis is to develop models of fracture networks consistent with both local-scale and global-scale observations. Bidimensional models of fracture networks display a wide variety of flow structures ranging from the sole permeable fracture to the equivalent homogeneous medium. The type of the relevant structure depends not only on the density and the length and aperture distributions but also on the observation scale. In several models, a crossover scale separates complex structures highly channeled from more distributed and homogeneous-like flow patterns at larger scales. These models, built on local characteristics and validated by global properties, have been settled in steady state. They have also been compared to natural well test data obtained in Ploemeur (Morbihan) in transient state. The good agreement between models and data reinforces the relevance of the models. Once validated and calibrated, the models are used to estimate the global tendencies of the main flow properties and the risk associated with the relative lack of data on natural fractures media. (author)

  12. New modelling method for fast reactor neutronic behaviours analysis; Nouvelles methodes de modelisation neutronique des reacteurs rapides de quatrieme Generation

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, P.

    2011-05-23

    Due to safety rules running on fourth generation reactors' core development, neutronics simulation tools have to be as accurate as never before. First part of this report enumerates every step of fast reactor's neutronics simulation implemented in current reference code: ECCO. Considering the field of fast reactors that meet criteria of fourth generation, ability of models to describe self-shielding phenomenon, to simulate neutrons leakage in a lattice of fuel assemblies and to produce representative macroscopic sections is evaluated. The second part of this thesis is dedicated to the simulation of fast reactors' core with steel reflector. These require the development of advanced methods of condensation and homogenization. Several methods are proposed and compared on a typical case: the ZONA2B core of MASURCA reactor. (author) [French] Les criteres de surete qui regissent le developpement de coeurs de reacteurs de quatrieme generation implique l'usage d'outils de calcul neutronique performants. Une premiere partie de la these reprend toutes les etapes de modelisation neutronique des reacteurs rapides actuellement d'usage dans le code de reference ECCO. La capacite des modeles a decrire le phenomene d'autoprotection, a representer les fuites neutroniques au niveau d'un reseau d'assemblages combustibles et a generer des sections macroscopiques representatives est appreciee sur le domaine des reacteurs rapides innovants respectant les criteres de quatrieme generation. La deuxieme partie de ce memoire se consacre a la modelisation des coeurs rapides avec reflecteur acier. Ces derniers necessitent le developpement de methodes avancees de condensation et d'homogenisation. Plusieurs methodes sont proposees et confrontees sur un probleme de modelisation typique: le coeur ZONA2B du reacteur maquette MASURCA

  13. Modelling of fractured reservoirs. Case of multi-scale media; Modelisation des reservoirs fractures. Cas des milieux multi-echelles

    Energy Technology Data Exchange (ETDEWEB)

    Henn, N.

    2000-12-13

    Some of the most productive oil and gas reservoirs are found in formations crossed by multi-scale fractures/faults. Among them, conductive faults may closely control reservoir performance. However, their modelling encounters numerical and physical difficulties linked with (a) the necessity to keep an explicit representation of faults through small-size grid blocks, (b) the modelling of multiphase flow exchanges between the fault and the neighbouring medium. In this thesis, we propose a physically-representative and numerically efficient modelling approach in order to incorporate sub-vertical conductive faults in single and dual-porosity simulators. To validate our approach and demonstrate its efficiency, simulation results of multiphase displacements in representative field sector models are presented. (author)

  14. Analysis and modelling of the fuels european market; Analyse et modelisation des prix des produits petroliers combustibles en europe

    Energy Technology Data Exchange (ETDEWEB)

    Simon, V

    1999-04-01

    The research focus on the European fuel market prices referring to the Rotterdam and Genoa spot markets as well the German, Italian and French domestic markets. The thesis try to explain the impact of the London IPE future market on spot prices too. The mainstream research has demonstrated that co-integration seems to be the best theoretical approach to investigate the long run equilibrium relations. A particular attention will be devoted to the structural change in the econometric modelling on these equilibriums. A deep analysis of the main European petroleum products markets permit a better model specification concerning each of these markets. Further, we will test if any evidence of relations between spot and domestic prices could be confirmed. Finally, alternative scenarios will be depicted to forecast prices in the petroleum products markets. The objective is to observe the model reaction to changes crude oil prices. (author)

  15. Development of renewable energies in the building industry and in the industry in general; Developpement des energies renouvelable dans le batiment et l'industrie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This third issue of the international DERBI conference has permitted to decipher the international actuality of renewable energies, to position the French national projects in this thriving context, and to discover the recent technological innovations. Californian companies were invited to this conference for a comparison of the policies in favor of renewable energy sources on both sides of the Atlantic ocean. This document gathers the transparencies presented at this conference and dealing with technologies, products, projects and realization in the following domains: solar cooling, biomass power plants, photovoltaic power plants and advances in photovoltaic engineering, solar thermal energy, thermodynamic solar power plants, architecture, renewable energies and the Eco-Building European project, biofuels, wood fuels, wind power and small wind power, geothermal energy. Presentations deal also with the financing of renewable energy projects, the competencies, employment and training, the numerical dimension, and the automation in the renewable energies domain. (J.S.)

  16. Conventional method for the calculation of the global energy cost of buildings; Methode conventionnelle de calcul du cout global energetique des batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-05-01

    A working group driven by Electricite de France (EdF), Chauffage Fioul and Gaz de France (GdF) companies has been built with the sustain of several building engineering companies in order to clarify the use of the method of calculation of the global energy cost of buildings. This global cost is an economical decision help criterion among others. This press kit presents, first, the content of the method (input data, calculation of annual expenses, calculation of the global energy cost, display of results and limitations of the method). Then it fully describes the method and its appendixes necessary for its implementation: economical and financial context, general data of the project in progress, environmental data, occupation and comfort level, variants, investment cost of energy systems, investment cost for the structure linked with the energy system, investment cost for other invariant elements of the structure, calculation of consumptions (space heating, hot water, ventilation), maintenance costs (energy systems, structure), operation and exploitation costs, tariffs and consumption costs and taxes, actualized global cost, annualized global cost, comparison between variants. The method is applied to a council building of 23 flats taken as an example. (J.S.)

  17. Methodologie d'evaluation de la demande de chaleur des groupes de batiments dans le cadre d'une etude de faisabilite du chauffage urbain

    Science.gov (United States)

    Quirion-Blais, Olivier

    In the context of energy efficiency improvements to pulp and paper mills, process modifications allow to free low quality steam. This kind of low pressure and temperature steam is often found to be in excess in mills. New opportunities to use this energy could be created by gathering plants along with local communities and other enterprises into eco-industrial clusters. Following this proposition, district heating is an interesting technology that could be developed. It consists in supplying buildings with steam or hot water from one or more central heating plants through a series of canalization, generally underground. The supplied energy is used mostly for space heating but it can also be used with appliances specially designed for this purpose. Under certain conditions, this type of heating is cheaper and more environmentally friendly for several reasons including the facts that one central boiler plant is more efficient and has lower pollutant emissions due to better combustion control. Moreover, it can be adapted to multiple fuels that are locally available such as biomass around some pulp and paper mills. However, to insure that the savings occur, the heat demand must be sufficiently high and concentrated. Therefore, detailed feasibility studies shall be conducted to justify significant investments. Such studies require a lot of time not to mention that they necessitate a lot of data which can be difficult to obtain. The objective of this work is to develop a methodology that can assess the feasibility of district heating quickly and using easily accessible data. It was mainly designed to determine the heat consumption, which is especially critical as to decide whether or not to implement this technology. The focus is primarily directed on residential buildings, but another methodology is also developed to take into account the commercial and institutional buildings demand. An analysis of the sources of data revealed a certain redundancy among them. Therefore, four different computation procedures were developed to obtain the heat consumption of residential buildings: • C1, the first procedure, is the most time consuming one. It is also the one that uses the most specific information from the case: aerial photographs, census data (building year of construction and type (single family detached, single family attached, apartments or mobile homes)) and punctual on-site verification from the target area. National estimates of thermal requirements values are also used. • C2, the second procedure, is less specific than C1, but is much less time consuming to achieve. The local data sources used are: aerial photographs and census data from the case. While the national ones are: estimates of the building heating surfaces and thermal requirements. • C3 and C4, are the easiest procedures. Those two are very similar. The specific data used in these cases are census data from the locations under study. National data used for C3 are building surface estimates and thermal requirements values while C4 only uses thermal requirement values which are slightly different from those of C3. A further analysis revealed later that these two calculations yielded the same results. Therefore, since C3 is slightly more complicated to implement, it was removed from further analysis. Using three procedures thus ensures the stability of the methodology when the three results are the same order of magnitude. An average of the three results gives a good estimation of the consumption. The methodology was then applied to four study cases. One of them has already been the subject of a detailed district heating assessment feasibility study. It is used to validate the results obtained with the new methodology. The three other cases are rather used to test different conditions (number, density, type and year of construction of buildings). The validation results showed that the methodology can determine the heat consumption to about 20% of the baseline value. It also determines the total heating surface to about 5%. The three other study cases, A, B and C, have confirmed that possibility of applying the methodology in various conditions. Case A showed lower gaps between the four procedures when the rate of single family houses is lower. Since this rate is high in the validation case, better results can be expected for cases where the number of single family houses is low, such as in case A. In case B, the global results showed a particularly low gap between the four procedures with a maximum of 5%. However, an analysis of individual dissemination areas showed higher positive and negative gaps, which, when they are summed, compensate for the individual errors. The bigger errors in this case are explained by the fact that the apartments in this city are larger than the national average. Case C presented an additional challenge since no aerial photo was available. It has nevertheless been possible to realize two calculation procedures, C3 and C4, which provided a broad approximation of the consumption. For the commercial sector, a similar methodology to that of the residential sector is developed. However, the lack of global data has prescribed the individual processing of every building. This approach is also justified by the fact that commercial and institutional buildings are less numerous and have higher consumption. Due to the extended duration of this type of approach, only the validation and case Aare realized. The first one confirmed the better results than the ones from the residential sector with a gap of 7% compared to the consumption baseline. The results from case A showed the areas where the heat consumption is higher. Furthermore, it showed that the commercial and institutional demand accounts for 10% to 40% of the total heat demand. The integration of the results obtained into a district heating feasibility study is then discussed. A joint analysis of the residential and the commercial and institutional sectors showed the importance of considering each building's heat consumption for the planning of a district heating network. The profitability of the study cases is considered in relation to the thermal thresholds suggested in the literature.

  18. Poultry farming buildings. Natural gas heating. Guidebook of installation rules; Batiments d`elevage avicole. Chauffage au gaz. Guide des regles d`installation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The technical and economical performances of a poultry farm are greatly influenced by the mastery of ambient temperature during the first days of husbandry. The natural gas space heating installation must answer these requirements and also respect all safety rules concerning the personnel and the animals. In order to answer the questions of poultry farming professionals, the technical association of the natural gas industry (ATG) in France and the Groupama insurance company have redefined the new version of this brochure which integrates the recent technological advances and defines the minimum quality and safety rules required to achieve a natural gas heating installation. The different topics presented are: the gas supply (aerial fixed reservoirs), the general distribution panel (location, command systems, regulation systems for LPG installations, electrical equipments), the distribution pipes (general supply, indoor pipes, flexible pipes, pipe fittings), the heating systems (power, choice, power supply, fastening, air renewal), the check and sign and the start-up of the installation, the periodical control and maintenance operations. (J.S.)

  19. Guidebook of natural gas air conditioning in the buildings of territorial organizations; Guide de la climatisation gaz naturel dans les batiments des collectives territotiales

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    In the framework of the 'common energy' approach, a partnership between Gaz de France (GdF) and the territorial associations (association of French territorial engineers (AITF) and association of French territorial graduate technicians (ATTF)), the publication since 15 years of this book of good practices makes a status of the implementation of natural gas air-conditioning in the buildings of the territorial organizations. Its aim is to supply information about the absorption principle, the existing products, the design of a natural gas air-conditioning system, its implementation, exploitation and maintenance. It presents also some experience feedbacks (town halls, swimming pools..) and three reference files in appendix. (J.S.)

  20. Ein semi-analytisches Modell zur dynamischen Berechnung des gekoppelten Systems Fahrzeug-Fahrweg-Untergrund für das Oberbausystem Feste Fahrbahn

    OpenAIRE

    Dinkel, Jens

    2007-01-01

    Zur dynamischen Berechnung des Oberbausystems Feste Fahrbahn wird ein semi-analytisches Modell entwickelt, das die wesentlichen Elemente des Schienenverkehrs enthält. Das Fahrzeug, der Oberbau und der Untergrund sind durch geeignete mechanische Modelle abgebildet und über dynamische Interaktionsbeziehungen verknüpft. Als Lösungsverfahren kommt die Fouriertransformation zum Einsatz, die eine Betrachtung und Bewertung der dynamischen Effekte im Frequenz- und Wellenzahlraum ermöglicht. Die Tragp...

  1. Advanced modeling of the size poly-dispersion of boiling flows; Modelisation avancee de la polydispersion en taille des ecoulements bouillants

    Energy Technology Data Exchange (ETDEWEB)

    Ruyer, Pierre; Seiler, Nathalie [Cadarache Batiment 700, IRSN/DPAM/SEMCA/LEIDC, BP 3, 13 115 Saint Paul lez Durance cedex (France)

    2008-07-01

    Full text of publication follows: This work has been performed within the Institut de Radioprotection et de Surete Nucleaire that leads research programs concerning safety analysis of nuclear power plants. During a LOCA (Loss Of Coolant Accident), in-vessel pressure decreases and temperature increases, leading to the onset of nucleate boiling. The present study focuses on the numerical simulation of the local topology of the boiling flow. There is experimental evidence of a local and statistical large spectra of possible bubble sizes. The relative importance of the correct description of this poly-dispersion in size is due to the dependency of (i) main hydrodynamic forces, like lift, as well as of (ii) transfer area with respect to the individual bubble size. We study the corresponding CFD model in the framework of an ensemble averaged description of the dispersed two-phase flow. The transport equations of the main statistical moment densities of the population size distribution are derived and models for the mass, momentum and heat transfers at the bubble scale as well as for bubble coalescence are achieved. This model introduced within NEPTUNE-CFD code of the NEPTUNE thermal-hydraulic platform, a joint project of CEA, EDF, IRSN and AREVA, has been tested on boiling flows obtained on the DEBORA facility of the CEA at Grenoble. These numerical simulations provide a validation and attest the impact of the proposed model. (authors) [French] Un programme de Recherche et Developpement dans le domaine de l'Accident de Perte du Refrigerent Primaire, sur un Reacteur a Eau sous Pression, a ete lance par l'Institut de Radioprotection et de Surete Nucleaire, a la Direction de Prevention des Accidents Majeurs. Au cours d'un transitoire accidentel de type APRP, le denoyage du coeur du reacteur conduit a une ebullition locale du fluide sur la paroi des crayons accompagnee d'une montee en temperature des gaines des crayons, terminee par une phase de renoyage

  2. Kinetic Modeling of Complex Catalytic Reactions Modélisation cinétique des réactions catalytiques complexes

    Directory of Open Access Journals (Sweden)

    Froment G. F.

    2006-11-01

    Full Text Available The paper deals with hydrocracking on metal-loaded zeolites. A fundamental approach is presented in which the detailed reaction network of the feed components of a complex feedstock is retained to a maximum extent. The kinetics are developed in terms of the elementary steps and single events involved in the reactions. Plausible assumptions and thermodynamic constraints limit the number of kinetic parameters. These do not depend on the chain length of the hydrocarbons and are not affected by the feed composition. Certainly, chemical analysis still imposes a certain degree of lumping of components and reaction networks, but not to the extent reflected by present day models. L'article traite de l'hydrocraquage sur des zéolites chargés en métaux. Dans l'approche fondamentale qui est présentée, le réseau de réaction des composants d'une charge complexe est retenu au maximum. La cinétique est établie en suivant pas à pas le déroulement et les étapes élémentaires des réactions. Des hypothèses plausibles et des contraintes thermodynamiques limitent le nombre de paramètres cinétiques. Ceux-ci ne dépendent pas de la longueur de la chaîne des hydrocarbures et ne sont pas affectés par la composition de la charge. L'analyse chimique impose bien sûr encore un certain agrégat des composants et des réseaux de réaction, mais moins que ne reflètent les modèles actuels.

  3. Non-Equilibrium Gas Dynamics - From Physical Models to Hypersonic Flights (Dynamique des gaz non- equilibres - Des modeles physiques jusqu’au vol hypersonique)

    Science.gov (United States)

    2009-09-01

    integrate for an efficient energy transfer modelling. Advanced modelling are also proposed including kinetics and radiation in simple application...chimie aéro- thermique . Elle vise, en particulier, à mieux prévoir les charges thermiques qui s’appliquent sur les corps en rentrée atmosphérique

  4. Modelling compressible multiphase flows Quelques résultats concernant la modélisation des écoulements multiphasiques

    Directory of Open Access Journals (Sweden)

    Coquel Frédéric

    2013-07-01

    Full Text Available We give in this paper a short review of some recent achievements within the framework of multiphase flow modeling. We focus first on a class of compressible two-phase flow models, detailing closure laws and their main properties. Next we briefly summarize some attempts to model two-phase flows in a porous region, and also a class of compressible three-phase flow models. Some of the main difficulties arising in the numerical simulation of solutions of these complex and highly non-linear systems of PDEs are then discussed, and we eventually show some numerical results when tackling two-phase flows with mass transfer. Nous présentons dans cet article quelques résultats récents concernant la modélisation et la simulation numérique des écoulements multiphasiques. Nous nous concentrons tout d’abord sur une classe de modèles diphasiques compressibles, en détaillant les lois de fermeture et les principales propriétés du sytème. Nous résumons ensuite brièvement les propositions de modélisation d’écoulements diphasiques en milieu poreux et d’écoulements triphasiques. Quelques difficultés apparaissant dans la simulation numérique de ces modèles sont présentées, et des résultats récents comportant un transfert de masse entre phases sont finalement décrits.

  5. Denomination et categorisation des modeles d'enseignement des langues: entre institution et pratique (Denomination and Categorization of Language Teaching Models: Between Institution and Practice).

    Science.gov (United States)

    Gajo, Laurent; Matthey, Marinette

    1998-01-01

    The process and issues of labeling language program models is discussed insofar as it may affect the objectives, content, and method of instruction. The first section describes the origins, stated objectives, and implementation of a Neuchatel (Switzerland) school program integrating heritage language and culture into the school curriculum, noting…

  6. Gas Well Testing Analysis Using Finite-Difference Models and Optimization Techniques Analyse d'essais de puits de gaz par des modèles utilisant la méthode des différences finies et par des techniques d'optimisation

    Directory of Open Access Journals (Sweden)

    Darderes E. A.

    2006-11-01

    Full Text Available In reservoir engineering studies of gas fields, three important parameters are needed: the permeability-thickness product, the skin factor, and the inertial-turbulent factor. Several methods have been proposed to determine these parameters from gas well tests. The most powerful one is the pseudo-steady state analysis, where a linear dependence on a semilogarithmic plot is found between the real gas pseudo-pressure and time. Another one is the type-curve matching. Both have drawbacks because they can be rigorously applied only to specific cases. An automated type-curve match, which provides a general method to analyze well test data, is presented in this paper. It is based on the adjustment of a numerical model to gas well test data, by means of optimization techniques. The numerical model is the solution of the second order strongly non-linear partial differential equation which rules the radial flow of real gases towards a well. The differential equation is solved by finite-differences, taking into account the variation of gas properties with pressure. In order to simulate any gas well test, appropriate initial and boundary conditions are imposed. The least squares method is used to minimize residual differences between actual pressures measured during test and computed pressures. Two optimization techniques are applied to obtain the best estimate of parameters that minimize the sum of the square of the residuals: the univariate method of Fibonacci [1] and the multivariate method of Marquardt [1, 2]. This procedure is applied to a single-rate and a two-rate drawdown test. Numerical results showed excellent agreement with well test data. Les études de gisements de gaz rendent indispensables la connaissance de trois paramètres importants : la capacité de flux (produit de la perméabilité par l'épaisseur de la couche productrice, l'effet de peau et le facteur d'inertie et de turbulence. On connaît plusieurs méthodes pour déterminer ces

  7. Modélisation des structures chimiques des macromolécules sédimentaires : le logiciel XMOL Software Modeling the Chemical Structures of Sedimentary Macromolecules: the Xmol Software

    Directory of Open Access Journals (Sweden)

    Faulon J. L.

    2006-11-01

    Full Text Available Cet article présente le logiciel XMOL qui prédit et construit, dans un espace tridimensionnel, des structures de macromolécules sédimentaires. La prédiction a pour base une bibliothèque de molécules et un système d'équations. La bibliothèque contient les groupes moléculaires (domaines aromatiques, naphténoaromatiques, naphténiques et chaînes aliphatiques présents dans la matière organique. Elle est générée par l'utilisateur à l'aide d'un éditeur de molécules. La liste des éléments choisis n'est pas exhaustive, toute nouvelle molécule analysée peut et doit être insérée dans la bibliothèque. Le système d'équations linéairement indépendantes traduit les résultats des analyses physico-chimiques ainsi qu'un certain nombre d'hypothèses. Les hypothèses révèlent l'insuffisance des données analytiques; elles devraient à terme disparaître. Les structures macromoléculaires prédites sont des combinaisons linéaires des éléments de la bibliothèque solutions du système d'équations. Elles sont cohérentes d'un point de vue statistique avec les résultats d'analyse. La construction des structures utilise des techniques d'algorithmique graphique et géométrique. Les macromolécules modélisées ont une conformation réaliste. This article describes the XMOL software used for predicting and constructing the structures of sedimentary macromolecules in a 3-D space. Prediction is based on a molecule library and a system of linear equations. The library contains the molecular groups (aromatic, naphtheno-aromatic and naphthenic domains and aliphatic chains present in organic matter. It is generated by the user by means of a molecule editor. The list of elements chosen is not exhaustive. Any new molecule identified by analyses can and must be inserted into the library. The system of linearly independant equations reflects the results of physicochemical analyses as well as a number of hypotheses. The hypotheses

  8. Modelling of the reactive transport of organic pollutants in ground water; Modellierung des reaktiven Transports organischer Schadstoffe im Grundwasser

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, W. [Heidelberg Univ. (Germany). Inst. fuer Umweltphysik

    1999-07-01

    The book describes reactive transport of organic pollutants in ground water and its quantitative monitoring by means of numerical reaction transport models. A brief introduction dealing with the importance of and hazards to ground water and opportunities for making use of ground water models is followed by a more detailed chapter on organic pollutants in ground water. Here the focus is on organochlorine compounds and mineral oil products. Described are propagation mechanisms for these substances in the ground and, especially, their degradability in ground water. A separate chapter is dedicated to possibilities for cleaning up polluted ground water aquifers. The most important decontamination techniques are presented, with special emphasis on in-situ processes with hydraulic components. Moreover, this chapter discusses the self-cleaning capability of aquifers and the benefits of the application of models to ground water cleanup. In the fourth chapter the individual components of reaction transport models are indicated. Here it is, inter alia, differences in the formulation of reaction models as to their complexity, and coupling between suspended matter transport and reaction processes that are dealt with. This chapter ends with a comprehensive survey of literature regarding the application of suspended matter transport models to real ground water accidents. Chapter 5 consists of a description of the capability and principle of function of the reaction transport model TBC (transport biochemism/chemism). This model is used in the two described applications to the reactive transport of organic pollutants in ground water. (orig.) [German] Inhalt des vorliegenden Buches ist die Darstellung des reaktiven Transports organischer Schadstoffe im Grundwasser und dessen quantitative Erfassung mithilfe numerischer Reaktions-Transportmodelle. Auf eine kurze Einleitung zur Bedeutung und Gefaehrdung von Grundwasser und zu den Einsatzmoeglichkeiten von Grundwassermodellen folgt ein

  9. Evaluation des dommages des punaisese( Heteroptera ) et des ...

    African Journals Online (AJOL)

    L'analyse statistique des résultats dans les blocs témoins montre que les punaises occasionnent plus de dommages aux boutons floraux et aux capsules vertes immatures que les chenilles. Sur les jeunes capsules, la moyenne des dommages des punaises et des chenilles reste statistiquement identique. Les traitements ...

  10. Inventory of the French data about the air quality inside buildings; Inventaire des donnees francaises sur la qualite de l'air a l'interieur des batiments

    Energy Technology Data Exchange (ETDEWEB)

    Mosqueron, L.; Nedellec, V.

    2001-12-01

    In the framework of the implementation of the French observatory for the indoor air quality (OQAI), the Vincent Nedellec consulting office (VNC) has carried out an inventory study of the French data relative to the air quality inside buildings on request of the building scientific and technical center (CSTB). Only data relative to dwellings, office and school buildings are considered. The pollutants considered in this study are: nitrogen dioxide (NO{sub 2}), inert particulates, carbon monoxide (CO), volatile organic compounds (VOCs: benzene, glycol ethers, formaldehyde), bacteria, legionella, fungi, moulds, animal allergens, radon, asbestos and artificial mineral fibers, lead, biocides. The objective is to identify the available French data, to collect them and to analyze their validity, in particular in terms of methodology, representativeness and extrapolation. Data are presented separately for each pollutant. (J.S.)

  11. Contamination des eaux souterraines par le lixiviat des décharges ...

    African Journals Online (AJOL)

    La percolation du lixiviat en provenance des dechets des decharges constitue une source de pollution des ressources en eau souterraine par infiltration, constituant ainsi une menace aussi importante que celle liee a l'accentuation du deficit hydrique. La decharge publique de Larache constitue un modele type de ...

  12. Model-Based Throttle Control using Static Compensators and Pole Placement Commande des gaz basée sur un modèle utilisant des compensateurs statiques et un placement de pôles

    Directory of Open Access Journals (Sweden)

    Thomasson A.

    2011-10-01

    Full Text Available In modern spark ignited engines, the throttle is controlled by the Electronic Control Unit (ECU, which gives the ECU direct control of the air flow and thereby the engine torque. This puts high demands on the speed and accuracy of the controller that positions the throttle plate. The throttle control problem is complicated by two strong nonlinear effects, friction and limp-home torque. This paper proposes the use of two, simultaneously active, static compensators to counter these effects and approximately linearize the system. A PID controller is designed for the linearized system, where pole placement is applied to design the PD controller and a gain scheduled I-part is added for robustness against model errors. A systematic procedure for generating compensator and controller parameters from open loop experiments is also developed. The controller performance is evaluated both in simulation, on a throttle control benchmark problem, and experimentally. A robustness investigation pointed out that the limp-home position is an important parameter for the controller performance, this is emphasized by the deviations found in experiments. The proposed method for parameter identification achieves the desired accuracy. Au sein des moteurs à allumage commandé modernes, les gaz sont régulés par le boîtier de commande électronique (ECU; Electronic Control Unit, qui permet la régulation directe par l’ECU du flux d’air et ainsi du couple moteur. Cela conduit à des exigences élevées quant à la vitesse et à la précision du régulateur qui positionne le papillon des gaz. Le problème de commande des gaz est compliqué par deux forts effets non linéaires, le frottement et le couple de mode de secours (“limp-home”. Cet article propose l’utilisation de deux compensateurs statiques, actifs simultanément, pour contrer ces effets et linéariser approximativement le système. Un régulateur PID est conçu pour le système linéarisé, où un

  13. Des interfaces intelligentes pour les modèles de gisements Intelligent Interfaces for Reservoir Models

    Directory of Open Access Journals (Sweden)

    Zucchini P.

    2006-11-01

    Full Text Available Les codes de simulation numérique nécessitent souvent l'entrée de données nombreuses et variées. Nous présentons un programme interactif d'aide à la constitution d'un jeu de données pour un modèle de simulation de l'évolution des fluides dans un gisement d'hydrocarbures pendant son exploitation. Nous avons utilisé un moteur d'inférences et un générateur d'écrans de saisie pour écrire cette interface. Cette approche comporte de nombreux avantages concernant la qualité du logiciel produit : fiabilité, extensibilité, facilité d'utilisation, etc. L'utilisation combinée de règles d'expertise et d'un langage orienté objet offre de nouvelles perspectives qui sont étudiées. En conclusion, nous proposons l'extension de cette démarche pour développer une interface commune aux logiciels en Exploration - Production. Numerical simulation software often needs many input data having different natures. This article describes an interactive software that is of help in building the input data fill needed by oil reservoir simulators. A professional inference engine has been used to build this interface. This approach offers many advantages concerning the quality of the software produced, i. e. reliability, extensibility, user friendliness, etc. New prospects opened up by the mixed use of expertise rules and object-oriented languages are pointed out. The conclusion emphasizes the extension of this approach to the development of a common interface for exploration-production software.

  14. Study on molecular modelling of the selectivity of catalysts for heavy petroleum fractions hydrocracking; Etude sur molecule modele des parametres regissant la selectivite des catalyseurs d'hydrocraquage des charges lourdes

    Energy Technology Data Exchange (ETDEWEB)

    Leite, L.

    2000-10-19

    Hydrocracking is a catalytic petroleum refining process that is commonly applied to upgrade the heavier fractions obtained from the distillation of crude oils. Nowadays the European demand for good quality middle distillates (kerosene and gas-oil) is high and one important goal for the refining is to transform selectively feedstocks into middle distillates. To understand how this transformation occurs, studies on model compounds have been investigated. Numerous studies have been devoted to paraffin hydrocracking. However theses molecules do not fully represent heavy petroleum fraction. Taking into account that the trend in the future will be to treat heavier feedstocks containing a large quantity of PNA (Polynuclear Aromatic hydrocarbons), the understanding of their transformation under hydrocracking conditions is a key point. In this study, we studied hydrocracking of phenanthrene over platinum on acid solids catalysts. Our main aim was to compare hydrocracking catalysts in term of catalytic activity and selectivity toward primary products thanks to our model reaction and to correlate these catalytic performances with acid solid properties and especially to rationalize the effects due to the acidity and the porosity of the acid solids. Catalytic experiments emphasised an effect of the porous structure on the selectivities. The acidity of the catalysts seemed to impose the catalytic activity but did not permit to explain the selectivities. This 'effect of the structure' has been clarified with the simulation of intermediate products adsorption and diffusion in the studied structures thanks to a molecular modelling study. Indeed, the selectivities obtained during phenanthrene hydrocracking have been linked up with the intermediate products adsorption energies in the structures. The results of this study permit to propose that the key-step for selectivities determination is the physical desorption of the primary products. (author)

  15. Modeling Airport Ground Operations using Discrete Event Simulation (DES) and X3D Visualization

    Science.gov (United States)

    2008-03-01

    for Advanced Graphical Environments SMAL Savage Modeling Analysis Language VRML Virtual Reality Markup Language SRTM Shuttle Radar Topography...the successor to the Virtual Reality Modeling Language ( VRML ). X3D features extensions to VRML (e.g. Humanoid Animation, NURBS, GeoVRML etc...formats as for example, it can export into VRML format so the model can be exploited and modeled in other 3D editing tools such as X3D-Edit . Its

  16. Power plant investment cycles in liberalised markets. A model of the German electricity generation market; Zyklen bei Kraftwerksinvestitionen in liberalisierten Maerkten. Ein Modell des deutschen Stromerzeugungsmarktes

    Energy Technology Data Exchange (ETDEWEB)

    Gaidosch, Lars

    2008-07-01

    In the course of the next ten to fifteen years almost half of Germany's installed power plant capacity will need to be replaced by the construction of new facilities. The power plant investments required for this will be made in an environment marked by liberalisation and competition. This is the context of the present article, which analyses the causes behind the cyclical behaviour of power plant investment and identifies factors that influence it. Cycles in this connection are defined as recurring oscillations in power plant capacity and electricity prices. The authors also propose measures that could dampen the cyclical course of power plant investment over time. One of the major outcomes of the present model calculations is that the power production market, similarly to other capital-intensive branches of industry, is expected to experience strong price fluctuations in the future as well. As it has been framed up to now, the German electricity wholesale market will not be able to prevent the occurrence investment cycles in power plant construction. One way to counteract investment cycles would be to greatly expand the time horizon of the liquid spot market through greater activity on the part of trading firms. [German] In den naechsten 10 bis 15 Jahren sind in Deutschland und Europa sowie weltweit knapp die Haelfte der installierten Kraftwerksleistung zu ersetzen bzw. neu zu errichten. Die hierfuer erforderlichen Kraftwerksinvestitionen finden heute unter den veraenderten Rahmenbedingungen der Liberalisierung und des Wettbewerbs statt. In diesem Zusammenhang werden Ursachen von Zyklen bei Kraftwerksinvestitionen analysiert und deren Einflussfaktoren aufgezeigt. Zyklen werden als wiederkehrende Schwankungen der Kraftwerkskapazitaeten und Strompreise definiert. Zusaetzlich werden Massnahmen vorgeschlagen, die eine Zyklenbildung bei Kraftwerksinvestitionen abschwaechen koennen. Zunaechst erfolgt eine Untersuchung unter welchen Bedingungen

  17. A Unified Model for Slug Flow Generation Modélisation de la formation des bouchons : vers un modèle stochastique unifié

    Directory of Open Access Journals (Sweden)

    Bernicot M.

    2006-11-01

    Full Text Available In order to improve the global safety and reliability level of multi-phase production systems and to guarantee their economical efficiency, we need a better understanding and control of hydraulic instabilities observed at the outlet of multi-phase sea-lines. This may be obtained through the development of slug flow stochastic models, which must be able to explain:(a The generation of the various types of slug length distributions which are observed on experimental data sets. (b The evolution of these distributions along the sea-lines up to their outlets, where large hydraulic fluctuations may be dangerous for the treatment installations. Based on experimental as well as theoretical arguments, we present such a model with emphasis on slug generation. We give a detailed theoretical analysis, together with a discussion of the underlying assumptions which justify the introduction of this model. Ce résumé contient des formules (*** qui ne peuvent s'afficher à l'écran. Pour garantir à la fois la sûreté de fonctionnement et la rentabilité des systèmes de production avec transport polyphasique, il est nécessaire de mieux comprendre et maîtriser les phénomènes d'instabilité hydraulique dans les conduites polyphasiques. Ceci suppose la mise au point et l'utilisation de Modèles de Simulation des écoulements portant, non seulement sur l'évolution dans le temps et en tout point de la conduite des valeurs moyennes des diverses variables (cf. le modèle TACITE, mais aussi sur leurs aspects stochastiques en prenant spécialement en compte : - les lois statistiques propres des divers mécanismes fondamentaux de formation des bouchons (distribution des longueurs de bouchons de liquide et de poches de gaz; - l'évolution de ces lois statistiques dans le temps et tout le long de la conduite (et ceci, jusqu'à son extrémité, extrémité dont les caractéristiques intéressent tout spécialement l'opérateur de la conduite. Nous présenterons ici

  18. Discrete modelling of rock-fill: Application to dams; Modelisation discrete des enrochements: Application aux barrages

    Energy Technology Data Exchange (ETDEWEB)

    Deluzarche, R.

    2004-12-15

    In this study, a discrete numerical model for rock-fill is built up and validated. This model is based upon the definition of bidimensional clusters that can break in different ways. The resistance of the inner bonds of the clusters are calibrated by reproducing the size-dependant resistance of rock blocks submitted to crushing tests. Numerical simulations of laboratory tests are performed on samples made of the different clusters. Tests on crushable clusters emphasize the utmost importance of particle crushing on the behaviour. A dam is modelled. The role of the placed-rock face on the stabilisation is underlined. The deformation of the dam during reservoir filling, as well as its good seismic behaviour is well reproduced by the model. The model makes it possible to show the influence of particle breakage on the settlements. (author)

  19. Human Behaviour Representation in Constructive Modelling (Representation du comportement humain dans des modelisations creatives)

    Science.gov (United States)

    2009-09-01

    fashion, etc. A related aspect of a goal-directed task representation (such as Hierarchical Task Analysis, HTA : Annett, 2003; Annett & Duncan, 1967) is...The pandemonium model employs daemons that shriek for attention (a metaphorical prioritisation scheme) although it isn’t necessarily a winner take all...Such phenomena might be better captured with a mixture of HTA and TNO’s pandemonium model, or some other task prioritization scheme, to reflect

  20. The hydro-mechanical modeling of the fractured media; Modelisation hydromecanique des milieux fractures

    Energy Technology Data Exchange (ETDEWEB)

    Kadiri, I

    2002-10-15

    The hydro-mechanical modeling of the fractured media is quite complex. Simplifications are necessary for the modeling of such media, but, not always justified, Only permeable fractures are often considered. The rest of the network is approximated by an equivalent continuous medium. Even if we suppose that this approach is validated, the hydraulic and mechanical properties of the fractures and of the continuous medium are seldom known. Calibrations are necessary for the determination of these properties. Until now, one does not know very well the nature of measurements which must be carried out in order to carry on a modeling in discontinuous medium, nor elements of enough robust validation for this kind of modeling. For a better understanding of the hydro-mechanical phenomena in fractured media, two different sites have been selected for the work. The first is the site of Grimsel in Switzerland in which an underground laboratory is located at approximately 400 m of depth. The FEBEX experiment aims at the in-situ study of the consecutive phenomena due to the installation of a heat source representative of radioactive waste in the last 17 meters of the FEBEX tunnel in the laboratory of Grimsel. Only, the modeling of the hydro-mechanical of the excavation was model. The modeling of the Febex enabled us to establish a methodology of calibration of the hydraulic properties in the discontinuous media. However, this kind of study on such complex sites does not make possible to answer all the questions which arise on the hydro-mechanical behavior of the fractured media. We thus carried out modeling on an other site, smaller than the fist one and more accessible. The experimental site of Coaraze, in the Maritime Alps, is mainly constituted of limestone and fractures. Then the variation of water pressure along fractures is governed by the opening/closure sequence of a water gate. Normal displacement as well as the pore pressure along these fractures are recorded, and then

  1. Mesure et modélisation multidimensionnelle des transferts thermiques gaz-paroi dans le cas des moteurs à allumage commandé Measurement and Multidimensional Modeling of Gas-Wall Heat Transfers in Spark-Ignition Engines

    Directory of Open Access Journals (Sweden)

    Gilaber P.

    2006-11-01

    Full Text Available A cette fin, deux étapes de recherche ont été mises en oeuvre : une phase expérimentale et une phase calcul. Dans la phase expérimentale, des mesures ont été faites sur un moteur monocylindre équipé de flux-mètres à réponse rapide. Chaque flux-mètre est composé d'un cylindre d'acier, contenant deux thermocouples. Dans le but de montrer l'influence de l'aérodynamique sur les échanges thermiques, un anémomètre à Laser a été utilisé à l'aide d'une entretoise placée entre culasse et cylindre. L'entretoise comportait deux hublots et deux flux-mètres permettant la mesure simultanée des flux thermiques et des paramètres aérodynamiques à l'extérieur de la couche limite. Deux flux-mètres supplémentaires ont été placés dans la culasse et le système d'acquisition permettait d'enregistrer simultanément dix voies de mesure à chaque degré vilebrequin, parmi lesquelles deux composantes de vitesse et la pression cylindre. Une étude paramétrique a révélé les tendances suivantes : - les pertes globales aux parois au cours d'un cycle thermodynamique diminuent lorsque le régime augmente, mais la valeur maximale des flux locaux augmente en raison de l'élévation du niveau de turbulence; - le remplissage a peu d'effet sur l'aérodynamique; son influence sur les transferts thermiques est due principalement à l'augmentation de la densité des gaz, qui se traduit par une augmentation des flux. Dans la phase calcul, deux idées de base ont guidé notre travail : - pour des raisons de temps de calcul prohibitif, il est impossible de mailler la couche limite; les échanges thermiques ont donc été estimés à l'aide d'une loi de paroi; - on fait l'hypothèse que les champs locaux de densité, vitesse et turbulence conditionnent fortement les flux thermiques; ce seront les paramètres de la loi de paroi. Dans cet esprit, le modèle de transferts thermiques de DIWAKAR a été introduit dans le code multi-dimensionnel KIVA. Une

  2. Modeling of pollutant emissions from road transport; Modelisation des emissions de polluants par le transport routier

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    COPERT III (computer programme to calculate emissions from road transport) is the third version of an MS Windows software programme aiming at the calculation of air pollutant emissions from road transport. COPERT estimates emissions of all regulated air pollutants (CO, NO{sub x}, VOC, PM) produced by different vehicle categories as well as CO{sub 2} emissions on the basis of fuel consumption. This research seminar was organized by the French agency of environment and energy mastery (Ademe) around the following topics: the uncertainties and sensitiveness analysis of the COPERT III model, the presentation of case studies that use COPERT III for the estimation of road transport emissions, and the future of the modeling of road transport emissions: from COPERT III to ARTEMIS (assessment and reliability of transport emission models and inventory systems). This document is a compilation of 8 contributions to this seminar and dealing with: the uncertainty and sensitiveness analysis of the COPERT III model; the road mode emissions of the ESCOMPTE program: sensitivity study; the sensitivity analysis of the spatialized traffic at the time-aggregation level: application in the framework of the INTERREG project (Alsace); the road transport aspect of the regional air quality plan of Bourgogne region: exhaustive consideration of the road network; intercomparison of tools and methods for the inventory of emissions of road transport origin; evolution of the French park of vehicles by 2025: new projections; application of COPERT III to the French context: a new version of IMPACT-ADEME; the European ARTEMIS project: new structural considerations for the modeling of road transport emissions. (J.S.)

  3. Modeling of turbulent bubbly flows; Modelisation des ecoulements turbulents a bulles

    Energy Technology Data Exchange (ETDEWEB)

    Bellakhal, Ghazi

    2005-03-15

    The two-phase flows involve interfacial interactions which modify significantly the structure of the mean and fluctuating flow fields. The design of the two-fluid models adapted to industrial flows requires the taking into account of the effect of these interactions in the closure relations adopted. The work developed in this thesis concerns the development of first order two-fluid models deduced by reduction of second order closures. The adopted reasoning, based on the principle of decomposition of the Reynolds stress tensor into two statistically independent contributions turbulent and pseudo-turbulent parts, allows to preserve the physical contents of the second order relations closure. Analysis of the turbulence structure in two basic flows: homogeneous bubbly flows uniform and with a constant shear allows to deduce a formulation of the two-phase turbulent viscosity involving the characteristic scales of bubbly turbulence, as well as an analytical description of modification of the homogeneous turbulence structure induced by the bubbles presence. The Eulerian two-fluid model was then generalized with the case of the inhomogeneous flows with low void fractions. The numerical results obtained by the application of this model integrated in the computer code MELODIF in the case of free sheared turbulent bubbly flow of wake showed a satisfactory agreement with the experimental data and made it possible to analyze the modification of the characteristic scales of such flow by the interfacial interactions. The two-fluid first order model is generalized finally with the case of high void fractions bubbly flows where the hydrodynamic interactions between the bubbles are not negligible any more. (author)

  4. Cloud Computing Security Model with Combination of Data Encryption Standard Algorithm (DES) and Least Significant Bit (LSB)

    Science.gov (United States)

    Basri, M.; Mawengkang, H.; Zamzami, E. M.

    2018-03-01

    Limitations of storage sources is one option to switch to cloud storage. Confidentiality and security of data stored on the cloud is very important. To keep up the confidentiality and security of such data can be done one of them by using cryptography techniques. Data Encryption Standard (DES) is one of the block cipher algorithms used as standard symmetric encryption algorithm. This DES will produce 8 blocks of ciphers combined into one ciphertext, but the ciphertext are weak against brute force attacks. Therefore, the last 8 block cipher will be converted into 8 random images using Least Significant Bit (LSB) algorithm which later draws the result of cipher of DES algorithm to be merged into one.

  5. Physical modelling of interactions between interfaces and turbulence; Modelisation physique des interactions entre interfaces et turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Toutant, A

    2006-12-15

    The complex interactions between interfaces and turbulence strongly impact the flow properties. Unfortunately, Direct Numerical Simulations (DNS) have to entail a number of degrees of freedom proportional to the third power of the Reynolds number to correctly describe the flow behaviour. This extremely hard constraint makes it impossible to use DNS for industrial applications. Our strategy consists in using and improving DNS method in order to develop the Interfaces and Sub-grid Scales concept. ISS is a two-phase equivalent to the single-phase Large Eddy Simulation (LES) concept. The challenge of ISS is to integrate the two-way coupling phenomenon into sub-grid models. Applying a space filter, we have exhibited correlations or sub-grid terms that require closures. We have shown that, in two-phase flows, the presence of a discontinuity leads to specific sub-grid terms. Comparing the maximum of the norm of the sub-grid terms with the maximum of the norm of the advection tensor, we have found that sub-grid terms related to interfacial forces and viscous effect are negligible. Consequently, in the momentum balance, only the sub-grid terms related to inertia have to be closed. Thanks to a priori tests performed on several DNS data, we demonstrate that the scale similarity hypothesis, reinterpreted near discontinuity, provides sub-grid models that take into account the two-way coupling phenomenon. These models correspond to the first step of our work. Indeed, in this step, interfaces are smooth and, interactions between interfaces and turbulence occur in a transition zone where each physical variable varies sharply but continuously. The next challenge has been to determine the jump conditions across the sharp equivalent interface corresponding to the sub-grid models of the transition zone. We have used the matched asymptotic expansion method to obtain the jump conditions. The first tests on the velocity of the sharp equivalent interface are very promising (author)

  6. Epidemiological study and spatial modeling of peste des petits ruminants (PPR in central area of Iran

    Directory of Open Access Journals (Sweden)

    Azam Mokhtari

    2017-05-01

    Full Text Available Objective. Estimate the prevalence and spatial modeling of PPR in the small ruminant population of Chaharmahal and Bakhtiari, Iran, during 2009–2014. Materials and methods. Data were collected from veterinary organization and Offices in Chaharmahal and Bakhtiari province and data analysis was carried out using and IBM SPSS version 22 and Office 2010. For spatial modeling geographic information system (QGIS and PCI-Geomatic was used. Results. This study showed that the overall prevalence of PPR during the years 2009 to 2014 was 1.37%. Koohrang, Ardal, Lordegan, Ben, Borougen, Shahrekord, Farsan and Kiar cities had the highest prevalence of PPR, respectively. The highest PPR infection rate was observed in the March and goat more affected rather than other ruminants. Conclusions. Our findings provide evidence of a rather common prevalence of PPR and its spatial distribution in Chaharmahal and Bakhtiari province. Using statistical tests for data analysis of PPR and its spatial modeling researchers can predict the incidence of disease in the future and could select appropriate measures of disease control.

  7. Kinetic modelling of hydrocracking catalytic reactions by the single events theory; Modelisation cinetique des reactions catalytiques d`hydrocraquage par la theorie des evenements constitutifs

    Energy Technology Data Exchange (ETDEWEB)

    Schweitzer, J.M.

    1998-11-23

    Kinetic modelling of petroleum hydrocracking is particularly difficult given the complexity of the feedstocks. There are two distinct classes of kinetics models: lumped empirical models and detailed molecular models. The productivity of lumped empirical models is generally not very accurate, and the number of kinetic parameters increases rapidly with the number of lumps. A promising new methodology is the use of kinetic modelling based on the single events theory. Due to the molecular approach, a finite and limited number of kinetic parameters can describe the kinetic behaviour of the hydrocracking of heavy feedstock. The parameters are independent of the feedstock. However, the available analytical methods are not able to identify the products on the molecular level. This can be accounted for by means of an posteriori lamping technique, which incorporates the detailed knowledge of the elementary step network. Thus, the lumped kinetic parameters are directly calculated from the fundamental kinetic coefficients and the single event model is reduced to a re-lumped molecular model. Until now, the ability of the method to extrapolate to higher carbon numbers had not been demonstrated. In addition, no study had been published for three phase (gas-liquid-solid) systems and a complex feedstock. The objective of this work is to validate the `single events` method using a paraffinic feedstock. First of all, a series of experiments was conducted on a model compound (hexadecane) in order to estimate the fundamental kinetic parameters for acyclic molecules. To validate the single event approach, these estimated kinetic coefficients were used to simulate hydrocracking of a paraffinic mixture ranging from C11 to C18. The simulation results were then compared to the results obtained from the hydrocracking experiments. The comparison allowed to validate the model for acyclic molecules and to demonstrate that the model is applicable to compounds with higher carbon numbers. (author

  8. Materials and electromagnetism. The modeling of composite materials; Materiaux en electromagnetisme. Modelisation des materiaux composites

    Energy Technology Data Exchange (ETDEWEB)

    Priou, A. [Institut Universitaire de Technologie, 92 - Ville-d' Avray (France)

    1999-01-01

    Maxwell laws are briefly described and the different types of electromagnetic materials are presented. Composite materials are made up of at least 2 phases: a host phase and an inclusion. The inclusion is a discontinuous phase coming from a conducting material (metal, carbon based material, semi-conductor, solid electrolytes or conducting polymers) and is spread within the host phase either in an aleatory or organized way. The modeling of such media can be made by 3 different approaches. In the multi-diffusion approach, the size of the particles enclosed in the host material and their mutual interactions are taken into account. The quasi-static approach allows the definition of an equivalent medium in order to describe percolation phenomena. The approach based on cluster theory gives a complete mathematical description of composite materials. The modeling of dielectric-conducting multilayer is also presented. The last part of the article is dedicated to the characteristics and applications of chiral media and of last generation electromagnetic materials. (A.C.)

  9. Contribution to the modelling of gas-solid reactions and reactors; Contribution a la modelisation des reactions et des reacteurs gaz-solide

    Energy Technology Data Exchange (ETDEWEB)

    Patisson, F

    2005-09-15

    Gas-solid reactions control a great number of major industrial processes involving matter transformation. This dissertation aims at showing that mathematical modelling is a useful tool for both understanding phenomena and optimising processes. First, the physical processes associated with a gas-solid reaction are presented in detail for a single particle, together with the corresponding available kinetic grain models. A second part is devoted to the modelling of multiparticle reactors. Different approaches, notably for coupling grain models and reactor models, are illustrated through various case studies: coal pyrolysis in a rotary kiln, production of uranium tetrafluoride in a moving bed furnace, on-grate incineration of municipal solid wastes, thermogravimetric apparatus, nuclear fuel making, steel-making electric arc furnace. (author)

  10. Therapeutischer Effekt des Protein-Tyrosinkinasehemmers Imatinib (STI571) im Modell der Monocrotalin-induzierten pulmonalen Hypertonie der Ratte

    OpenAIRE

    Dony, Eva Maria Marlene

    2006-01-01

    Die pulmonalarterielle Hypertonie (PAH) ist eine schwere, lebensbedrohliche Erkrankung, die durch eine deutliche, anhaltende Erhöhung des pulmonalarteriellen Druckes, charakteristische Umbauprozesse der Pulmonalarterien (Remodelling) und der Entwicklung eines Cor pulmonale gekennzeichnet ist. Das Voranschreiten der pulmonalen Hypertonie ist unter anderem verbunden mit gesteigerter Proliferation und Migration glatter Gefäßmuskelzellen der Lunge. Platelet derived growth factor (PDGF) ist ei...

  11. Simulation des fuites neutroniques a l'aide d'un modele B1 heterogene pour des reacteurs a neutrons rapides et a eau legere

    Science.gov (United States)

    Faure, Bastien

    The neutronic calculation of a reactor's core is usually done in two steps. After solving the neutron transport equation over an elementary domain of the core, a set of parameters, namely macroscopic cross sections and potentially diffusion coefficients, are defined in order to perform a full core calculation. In the first step, the cell or assembly is calculated using the "fundamental mode theory", the pattern being inserted in an infinite lattice of periodic structures. This simple representation allows a precise modeling for the geometry and the energy variable and can be treated within transport theory with minimalist approximations. However, it supposes that the reactor's core can be treated as a periodic lattice of elementary domains, which is already a big hypothesis, and cannot, at first sight, take into account neutron leakage between two different zones and out of the core. The leakage models propose to correct the transport equation with an additional leakage term in order to represent this phenomenon. For historical reasons, numerical methods for solving the transport equation being limited by computer's features (processor speeds and memory sizes), the leakage term is, in most cases, modeled by a homogeneous and isotropic probability within a "homogeneous leakage model". Driven by technological innovation in the computer science field, "heterogeneous leakage models" have been developed and implemented in several neutron transport calculation codes. This work focuses on a study of some of those models, including the TIBERE model from the DRAGON-3 code developed at Ecole Polytechnique de Montreal, as well as the heterogeneous model from the APOLLO-3 code developed at Commissariat a l'Energie Atomique et aux energies alternatives. The research based on sodium cooled fast reactors and light water reactors has allowed us to demonstrate the interest of those models compared to a homogeneous leakage model. In particular, it has been shown that a heterogeneous

  12. Atmospheric pollution. From processes to modelling; Pollution atmospherique. Des processus a la modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Sportisse, B. [Ecole Nationale des Ponts et Chaussees (ENPC), Centre d' Enseignement et de Recherche en Environnement Atmospherique, Lab. Commun ENPC, 75 - Paris (France)

    2008-07-01

    Air quality, greenhouse effect, ozone hole, chemical or nuclear accidents.. All these phenomena are tightly linked to the chemical composition of atmosphere and to the atmospheric dispersion of pollutants. This book aims at supplying the main elements of understanding of 'atmospheric pollutions': stakes, physical processes involved, role of scientific expertise in decision making. Content: 1 - classifications and scales: chemical composition of the atmosphere, vertical structure, time scales (transport, residence); 2 - matter/light interaction: notions of radiative transfer, application to the Earth's atmosphere; 3 - some elements about the atmospheric boundary layer: notion of scales in meteorology, atmospheric boundary layer (ABL), thermal stratification and stability, description of ABL turbulence, elements of atmospheric dynamics, some elements about the urban climate; 4 - notions of atmospheric chemistry: characteristics, ozone stratospheric chemistry, ozone tropospheric chemistry, brief introduction to indoor air quality; 5 - aerosols, clouds and rains: aerosols and particulates, aerosols and clouds, acid rains and leaching; 6 - towards numerical simulation: equation of reactive dispersion, numerical methods for chemistry-transport models, numerical resolution of the general equation of aerosols dynamics (GDE), modern simulation chains, perspectives. (J.S.)

  13. Mise au point d' un modele cartographique pour la description des stations forestieres en Ardenne belge

    Directory of Open Access Journals (Sweden)

    Lejeune P.

    2002-01-01

    Full Text Available Development of a cartographic mdel for the forest site types delineation in the Belgian Ardenne. The paper presents an original method dealing with the forest site types delineation. The suggested method consists in integrating a typological key in a GIS aiming at producing a thematic map that describes forest site types. Data used are the soil map of Belgium (digitized at the scale 1:20,000 and a digital elevation model built from a topographic map (scale 1:10,000. The typological key is mainly based on the methodology used by Thill et al. (1988 in the site types system for central Ardenne, the potential vegetation map of Sougnez and Dethioux (1975 and the ecoregion map of Delvaux and Galoux (1962. In that respect, site types are closely linked to the soil map and the phytosociological classification. So, they can be connected to the afforestation guide and different phytosociological and autecological studies concerning forest species. It is then possible to map the potential habitats or the site potentialities related to tree species. The key is valid for the Ardenne ecoregion located in Southern Belgium (elevation higher than 300 m. It has to be validated through an intensive use in the field, taking into account its imprecision linked to the types of collected data, chieffly those being digitized. The integration of such a tool in a SIG can be considered as an original way in terms of integrated forest management or forest sites description in the context of the project ""Natura 2000"" launched by the European Union. The study has been carried out within the framework of an experimental integrated management project concerning the Saint-Hubert forest (17,000 ha.

  14. Production polyphasique. Modélisation des écoulements à bouchons Multiphase Production Slug-Flow Modeling

    Directory of Open Access Journals (Sweden)

    Drouffe J. M.

    2006-11-01

    Full Text Available L'exploitation des hydrocarbures en mer reste une activité coûteuse et qui peut, même, se révéler, éventuellement dangereuse. Les concepts de production polyphasique tels que Poséidon permettent à la fois : - une réduction importante des coûts de production; - la suppression des risques humains liés à la présence permanente en mer d'équipes importantes. Les programmes de simulation des écoulements diphasiques actuellement disponibles pour la mise en oeuvre de ces concepts, sont tous basés sur une approche déterministeclassique. Cet article présente une nouvelle approche statistiquenon conventionnelle qui devrait nous permettre de mieux préciser les caractéristiques des écoulements à bouchons et donc de pouvoir mieux dimensionner et exploiter nos futures installations de production et transport polyphasique longue distance. Offshore hydrocarbon production remains a costly venture, and even one that might possibly be dangerous. Multiphase production concepts such as Poseidon make for both a considerable reduction in production costs and the elimination of human risks linked to the constant offshore presence of large crews. The two-phase flow simulation programs now available for implementing such concepts are all based on a standard deterministicapproach. This article describes a new and unconventional statisticalapproach that we feel more accurately describes the characteristics of slug flows and hence is more effecting for the sizing and operating of future production and long-distance pipelining installations.

  15. Inversion aided systems for stratigraphic models; Systemes d'aide a l'inversion des modeles stratigraphiques

    Energy Technology Data Exchange (ETDEWEB)

    Dobranszky, G.

    2005-12-15

    Stratigraphic modeling aims at rebuilding the history of the sedimentary basins by simulating the processes of erosion, transport and deposit of sediments using physical models. The objective is to determine the location of the bed-rocks likely to contain the organic matter, the location of the porous rocks that could trap the hydrocarbons during their migration and the location of the impermeable rocks likely to seal the reservoir. The model considered within this thesis is based on a multi-lithological diffusive transport model and applies to large scales of time and space. Due to the complexity of the phenomena and scales considered, none of the model parameters is directly measurable. Therefore it is essential to inverse them. The standard approach, which consists in inverting all the parameters by minimizing a cost function using a gradient method, proved very sensitive to the choice of the parameterization, to the weights given to the various terms of the cost function (hearing on data of very diverse nature) and to the numerical noise. These observations led us to give up this method and to carry out the in-version step by step by decoupling the parameters. This decoupling is not obtained by fixing the parameters but by making several assumptions on the model resulting in a range of reduced but relevant models. In this thesis, we show how these models enable us to inverse all the parameters in a robust and interactive way. (author)

  16. Micromechanical modelling of heterogeneous materials in transient conditions: contributions for the study of the ageing of structural components under service; Modelisation micromecanique des materiaux heterogenes en regimes transitoires: contributions en vue de l'etude du vieillissement des structures en service

    Energy Technology Data Exchange (ETDEWEB)

    Masson, R.

    2010-12-20

    The modelling of the mechanical behaviour of structural materials is increasingly based on microstructural parameters. Within this framework, homogenisation methods have the advantage of providing deductive methods which, starting from the properties and space distribution of each constituent, deduce the effective properties of the heterogeneous material. Nevertheless, many applications make still difficult the use of homogenisation methods. It is in particular the case of structural materials presenting elastic-viscoplastic behaviours and subjected to both non-monotone and ageing loadings. To progress on the treatment by homogenisation of these useful situations constitutes precisely the main idea of the various contributions presented in this work.For linear elasticity, new expressions for the computation of the Eshelby tensor are first of all established in order to improve the efficiency of homogenisation methods usually used. Always for linear behaviours but now viscoelastic, various approximations associated with the use of the theorem of correspondence are studied and compared. The equivalence of one of these approximations (the so-called 'collocation method') with an internal variables formulation of the effective behaviour is shown. This internal variables formulation leads to exact results in some situations and strongly simplifies the treatment of ageing linear viscoelastic behaviours. In the case of elastic-viscoplastic behaviours, is added to the previous difficulty (viscoelastic coupling) that of the treatment of nonlinear behaviour. Comparisons made between various families of estimates make it possible to determine the effects of the various approximations needed to deal with these nonlinearities. An improvement is also proposed and implemented in a particular case while the extension of this internal variable formulation to nonlinear behaviours is discussed. Finally, full-field computations of microstructures are also tackled by

  17. Des Connaissances Aux Politiques

    International Development Research Centre (IDRC) Digital Library (Canada)

    Dans beaucoup de pays en développement, la faible capacité du gouvernement est pratiquement la définition des problèmes de développement du pays. ...... Promouvoir l'échange des connaissances émanant des recherches ainsi que des outils et des résultats, et le dialogue entre les pays, institutions et donateurs.

  18. Variabilite des productions et des revenus des exploitations ...

    African Journals Online (AJOL)

    ... sont à dominance céréale et coton avec environ 75 % des assolements. Les revenus nets des EAF montrent en moyenne une prédominance des productions végétales (1 394 976 Fcfa) et animales, (1 420 430 Fcfa) sur les activités de diversification (358 449 Fcfa). Mots clés : production, revenu, économie, performance, ...

  19. Modeling of turbulent flows in cooling channels of turbo-machineries; Modelisation des ecoulements turbulents dans des canaux de refroidissement de turbomachines

    Energy Technology Data Exchange (ETDEWEB)

    Bidart, A.; Caltagirone, J.P.; Parneix, S. [Laboratoire MASTER-ENSCPB, 33 - Talence (France)

    1997-12-31

    The MASTER laboratory has been involved since several years in the creation and utilization of modeling tools for the prediction of 3-D turbulent flows and heat transfers in turbine blades in order to optimize the cooling systems of turbo-machineries. This paper describes one of the test-cases that has been used for the validation of the `Aquilon` calculation code developed in this aim. Then, the modeling performed with the `Fluent` industrial code in order to evaluate the possible improvements of the Aquilon code, is presented. (J.S.) 5 refs.

  20. Integration of dynamical data in a geostatistical model of reservoir; Integration des donnees dynamiques dans un modele geostatistique de reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Costa Reis, L.

    2001-01-01

    We have developed in this thesis a methodology of integrated characterization of heterogeneous reservoirs, from geologic modeling to history matching. This methodology is applied to the reservoir PBR, situated in Campos Basin, offshore Brazil, which has been producing since June 1979. This work is an extension of two other thesis concerning geologic and geostatistical modeling of the reservoir PBR from well data and seismic information. We extended the geostatistical litho-type model to the whole reservoir by using a particular approach of the non-stationary truncated Gaussian simulation method. This approach facilitated the application of the gradual deformation method to history matching. The main stages of the methodology for dynamic data integration in a geostatistical reservoir model are presented. We constructed a reservoir model and the initial difficulties in the history matching led us to modify some choices in the geological, geostatistical and flow models. These difficulties show the importance of dynamic data integration in reservoir modeling. The petrophysical property assignment within the litho-types was done by using well test data. We used an inversion procedure to evaluate the petrophysical parameters of the litho-types. The up-scaling is a necessary stage to reduce the flow simulation time. We compared several up-scaling methods and we show that the passage from the fine geostatistical model to the coarse flow model should be done very carefully. The choice of the fitting parameter depends on the objective of the study. In the case of the reservoir PBR, where water is injected in order to improve the oil recovery, the water rate of the producing wells is directly related to the reservoir heterogeneity. Thus, the water rate was chosen as the fitting parameter. We obtained significant improvements in the history matching of the reservoir PBR. First, by using a method we have proposed, called patchwork. This method allows us to built a coherent

  1. Phenomenological modeling of eddy current signals with a view to characterizing steam generator tube flaws; Modelisation phenomenologique des signaux courants de Foucault en vue de la caracterisation des defauts des tubes de generateurs de vapeur

    Energy Technology Data Exchange (ETDEWEB)

    La, R

    1997-12-31

    This work deals with the eddy current non-destructive test ing. Its long-term goal is to design an `inverse model` for evaluating the geometry an d the dimensions of steam generator tube flaws from eddy current signals. The approach we adopted requires the preliminary knowledge of a `forward model` that estimates the eddy current signal knowing the geometry and the dimensions of the flaws. A quasi-exhaustive study of the existing forward models showed their inadequacy to solve the inverse problem. Hence, we proposed to build a general forward model, appropriate to the inversion. Using a parametric approach, this model is phenomenological, i.e. it is based on observations made from results of a finite element code. For each position of the coil, the proposed forward model fist discretized the eddy current distribution into `tubes of current`. A parametric description of the shape of these tubes is given according the system constituted of the coil and the tubes of current as a `multi-transformer`, their current signal, can then be deduced. The model was validated in the case of an axisymmetric configuration. Comparisons with both analytical and numerical models showed very good agreements. Then, the proposed model was applied to a three-dimensional configuration. Comparisons with experimental results are sufficiently conclusive to validate the approach to the construction of the phenomenological model. However, before envisaging the inverse problem, the computation time, still too long, ought to be reduced and the parametric description needs to be generalized to other three-dimensional configurations. (author). 92 refs.

  2. Modelisation des effets physico-techniques pour la conception des ...

    African Journals Online (AJOL)

    automatisation dans les installations industrielles a besoin d'une régulation automatique des commandes des processus technologiques pour lesquelles certaines contraintes sont à relever compte tenu des exigences des innovations scientifiques de ...

  3. Therapeutischer Effekt des Serotonin-Antagonisten Tergurid im Modell der monocrotalin-induzierten pulmonalen Hypertonie der Ratte

    OpenAIRE

    Kulisch, Corinna

    2011-01-01

    Die pulmonale Hypertension stellt eine seltene, aber schwere, sehr stark einschränkende und lebensbedrohliche Erkrankung dar. Sie ist charakterisiert durch Vasokonstriktion, Umbauprozesse in den Pulmonalarterien und durch eine daraus folgende Erhöhung des pulmonalarteriellen Druckes. Serotonin (5-Hydroxytryptamin, 5-HT) spielt vor allem in der frühen Phase der Krankheitsentwicklung eine große Rolle, aber die pharmakologische Steuerung befindet sich momentan noch im präklinischen Bereich. ...

  4. Therapeutischer Effekt des Guanylatzyklasestimulators BAY 63-2521 im Modell der Monocrotalin-induzierten pulmonalen Hypertonie der Ratte

    OpenAIRE

    Kaulen, Christina

    2009-01-01

    Die pulmonalarterielle Hypertonie ist gekennzeichnet durch eine Erhöhung des pulmonalarteriellen Druckes, Umbauprozesse der Pulmonalarterien und Entwicklung eines Cor pulmonale. Sie stellt eine schwere, lebensbedrohliche Erkrankung dar, die die Lebensqualität der Betroffenen stark einschränkt. In der vorliegenden Arbeit konnte gezeigt werden, dass BAY 63-2521 als Stimulator der löslichen Guanylatzyklase in der Lage ist, die pulmonale Hypertonie im Monocrotalinmodell der Ratte zu s...

  5. Modelling atmospheric circulations for the study of Alpine valleys pollution; Modelisation des circulations atmospheriques pour l'etude de la pollution des vallees alpines

    Energy Technology Data Exchange (ETDEWEB)

    Brulfert, G.

    2004-11-15

    Local weather phenomena observed in alpine valleys frequently lead to the accumulation of emitted anthropogenic airborne species in the low layers of the atmosphere. The development of a numerical model allows reproducing the chemical evolution of air mass during POVA intensive period of observations. In Chamonix and Maurienne valley, computations of photochemical indicators (NO{sub y}, O{sub 3}/NO{sub z}, H{sub 2}O{sub 2}/HNO{sub 3}) prove the ozone regime to be control by volatile organic compounds. Moreover simulation highlighted that the major part of this secondary pollutant is regionally produced. The development of an indicator who localised ozone production sites can help to define abatement scenarios. The chemical mechanism RACM allows describing the evolution of many species. It is possible to conclude that in winter road traffic and heating are the main sources of volatile organic compounds. (author)

  6. Updating the model TREMOD - Mobile Machinery (TREMOD-MM); Aktualisierung des Modells TREMOD - Mobile Machinery (TREMOD-MM)

    Energy Technology Data Exchange (ETDEWEB)

    Helms, Hinrich; Lambrecht, Udo; Knoerr, Wolfram [ifeu - Institut fuer Energie- und Umweltforschung Heidelberg gGmbH, Heidelberg (Germany)

    2010-05-15

    In the context of the project ''Development of a model for the computation of the air pollutant emissions and the fuel consumption of combustion engines in mobile devices and machines'', the Institute for Energy and Environmental Research GmbH (Heidelberg, Federal Republic of Germany) has created the model TREMOD-MM (TREMOD Mobile Machinery). Thus a detailed computation of the emissions from mobile devices and machines in the agriculture, construction industry, forestry and gardening as well as the sport shipping and passenger shipping can be accomplished. Strongly differentiated data are considered to the age structure, engine performance, use and emission behaviour. Thus it is possible to compute the emissions for different scenarios in high degree of detail.

  7. variabilite des productions et des revenus des exploitations

    African Journals Online (AJOL)

    3Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR Innovation,. Montpellier, France. Doubangolo COULIBALY, Email kone_b@yahoo.fr. RESUME. La durabilité des systèmes de production à base de coton dans un contexte de variabilité des prix aux producteurs et de ...

  8. Light ions radiobiological effects on human tumoral cells: measurements modelling and application to hadron-therapy; Mesures et modelisation des effets radiobiologiques des ions legers sur des cellules tumorales humaines: application a l'hadrontherapie

    Energy Technology Data Exchange (ETDEWEB)

    Jalade, P

    2005-11-15

    In classical radiotherapy, the characteristics of photons interactions undergo limits for the treatment of radioresistant and not well located tumours. Pioneering treatments of patients at the Lawrence Laboratory at Berkeley has demonstrated two advantages of hadrons beams: the Relative Biologic Effect (the RBE) and the ballistic of the beams. Since 1994, the clinical centre at Chiba, has demonstrated successfully the applicability of the method. A physics group, managed by G. Kraft, at Darmstadt in Germany, has underlined the advantages of carbon beams. An European pool, called ENGIGHT (European Network for LIGHt ion Therapy) has been created in which the French ETOILE project appeared. The purpose of the thesis concerns measurements and models of 'in vitro' human cells survival. In the first part, the nowadays situation in particles interactions, tracks and cells structures and radiobiology is presented here. The second is devoted to the models based on the beam tracks and localization of the physical dose. Discussion of sensitivity to various parameters of the model has been realized with the help of numerical simulations. Finally the predictions of the improved model has been compared to experimental irradiations of human cells with argon and carbon beams of the GANIL machine. Conclusion of such study shows the performance and limits of a local model for predicting the radiobiological efficiency of light ions in hadron-therapy. (author)

  9. La metamorphose des cypris femelles des Rhizocephales

    NARCIS (Netherlands)

    Veillet, A.

    1964-01-01

    Depuis la découverte de la métamorphose des cypris de Sacculina carcini Thompson par Delage, peu de biologistes se sont intéressés au développement des Rhizocéphales. On admet aujourd'hui que tous les Cirripèdes parasites ont, comme Sacculina carcini, une forme kentrogone qui inocule le parasite au

  10. Modelling of the influence of the 'Flimserstein' tunnel on the Lag Tiert karstic spring in Flims; Modellierung des Einflusses des Flimserstein-Tunnels auf die Karstquelle des Lag Tiert (Flims, GR)

    Energy Technology Data Exchange (ETDEWEB)

    Jeannin, P.-Y.; Haeuselmann, P. [Schweizerisches Institut fuer Spelaeologie und Karstkunde SISKA, La Chaux-de-Fonds (Switzerland); Wildberger, A. [Dr. von Moos AG, Geotechnisches Buero, Zuerich (Switzerland)

    2007-12-15

    This report describes the modelling of the influence of the 'Flimserstein' tunnel on the Lag Tiert karstic spring in Flims, Switzerland. When the tunnel, that provides a by-pass for the mountain village of Flims, was built, a karstic system was broached. As a result, several springs dried up and others had their capacity reduced. Also, the quantity of water available for a local hydropower station was reduced. The report describes how the situation as far as the underground watercourses are concerned was modelled and how exactly the tunnel construction changed the water-quantities at the various springs. The results of the study are presented and discussed and recommendations are made concerning the modelling of such karstic systems.

  11. Neutrino mass and physics beyond the Standard Model; Masse des Neutrinos et Physique au-dela du Modele Standard

    Energy Technology Data Exchange (ETDEWEB)

    Hosteins, P

    2007-09-15

    The purpose of this thesis is to study, in the neutrino sector, the flavour structures at high energy. The work is divided into two main parts. The first part is dedicated to the well known mechanism to produce small neutrino masses: the seesaw mechanism, which implies the existence of massive particles whose decays violate lepton number. Therefore this mechanism can also be used to generate a net baryon number in the early universe and explain the cosmological observation of the asymmetry between matter and antimatter. However, it is often non-trivial to fulfill the constraints coming at the same time from neutrino oscillations and cosmological experiments, at least in frameworks where the couplings can be somehow constrained, like some Grand Unification models. Therefore we devoted the first part to the study of a certain class of seesaw mechanism which can be found in the context of SO(10) theories for example. We introduce a method to extract the mass matrix of the heavy right-handed neutrinos and explore the phenomenological consequences of this quantity, mainly concerning the production of a sufficient baryon asymmetry. When trying to identify the underlying symmetry governing the mixings between the different generations, we see that there is a puzzling difference between the quark and the lepton sectors. However, the quark and lepton parameters have to be compared at the scale of the flavour symmetry breaking, therefore we have to make them run to the appropriate scale. Thus, it is worthwhile investigating models where quantum corrections allow an approximate unification of quark and lepton mixings. This is why the other part of the thesis investigates the running of the effective neutrino mass operator in models with an extra compact dimension, where quantum corrections to the neutrino masses and mixings can be potentially large due to the multiplicity of states.

  12. Modelling of air flows in pleated filters and of their clogging by solid particles; Modelisation des ecoulements d'air et du colmatage des filtres plisses par des aerosols solides

    Energy Technology Data Exchange (ETDEWEB)

    Del Fabbro, L

    2002-07-01

    The devices of air cleaning against particles are widely spread in various branches of industry: nuclear, motor, food, electronic,...; among these devices, numerous are constituted by pleated porous media to increase the surface of filtration and thus to reduce the pressure drop, for given air flow. The objective of our work is to compensate a lack evident of knowledge on the evolution of the pressure drop of pleated filter during the clogging and to deduct a modelling from it, on the basis of experiments concerning industrial filters of nuclear and car types. The obtained model is a function of characteristics of the filtering medium and pleats, of the characteristics of solid particles deposited on the filter, of the mass of particles and of the aeraulic conditions of air flow. It also depends on data on the clogging of flat filters of equivalent medium. To elaborate this model of pressure drop, an initial stage was carried out in order to characterize, experimentally and numerically, the pressure drop and the distribution of air flow in clean pleated filters of nuclear (high efficiency particulate air filter, in fiberglasses) and car (mean efficiency filter, in fibers of cellulose) types. The numerical model allowed to understand the fundamental role played by the aeraulic resistance of the filtering medium. From an non-dimensional approach, we established a semi-empirical model of pressure drop for a clean pleated filter valid for both studied types of medium; this model is used of first base for the development of the final model of clogging. The study of the clogging of the filters showed the complexity of the phenomenon dependent mainly on a reduction of the surface of filtration. This observation brings us to propose a clogging of pleated filters in three phases. Both first phases are similar in those observed for flat filters, while last phase corresponds to a reduction of the surface of filtration and leads a strong increase of the filter pressure drop

  13. Modelling of the flow in the interface of a composite liner at the bottom of a municipal waste landfill; Modelisation des ecoulements dans les interfaces des barrieres d'etancheite composites des installations de stockage de dechets

    Energy Technology Data Exchange (ETDEWEB)

    Cartaud, F

    2004-11-15

    Composite liner at the bottom of waste landfill is based, in France, on a geo-membrane overlapping a compacted clay liner. Defects exist in geo-membranes and leachates, provided by water percolation through the waste, then flow in the interface between the two components of the lining system. The present work consisted in analysis, quantification and modelling of the leakage process in the interface. The experimental study has been carried out on a one-meter scale device in laboratory and allowed to assess the role of normal stress on the flow rate in interface. The case where a geo-textile is present beneath the geo-membrane has been also studied. The modelling allows to take into account more accurately the geometry of the interface and ensures a better quantification of leachate flow rates than using existing methods. (author)

  14. Developments in Spray Modeling in Diesel and Direct-Injection Gasoline Engines Progrès de la modélisation des sprays dans les moteurs Diesel et à essence

    Directory of Open Access Journals (Sweden)

    Kong S. C.

    2006-12-01

    Full Text Available In direct-injection engines, the fuel spray characteristics influence the combustion efficiency and exhaust emissions. The performance of available spray models for predicting liquid and vapor fuel distributions, and their influence on combustion is reviewed for both diesel and gasoline direct injection engines. A phenomenological nozzle flow model is described for simulating the effects of diesel injector nozzle internal geometry on the fuel injection and spray processes. The flow model provides initial conditions for the liquid jet breakup model that considers wave instabilities due to Kelvin-Helmholtz (KH and Rayleigh-Taylor (RT mechanisms. A linearized instability analysis has also been extended to consider the breakup of liquid sheets for modeling pressure-swirl gasoline injectors. Diesel engine predictions have been compared with extensive data from in-cylinder laser diagnostics carried out in optically accessible heavy-duty, DI Diesel engines over a wide range of operating conditions. The results show that the nozzle flow model used in combination with the KH and RT models gives realistic spray predictions. In particular, the limited liquid fuel penetration length observed experimentally and the flame shape details are captured accurately. The liquid sheet breakup model has also been compared favorably with experimental spray penetration and drop size data for gasoline hollow-cone sprays. This model is currently being applied to study stratified charge combustion in GDI engines. Dans les moteurs à injection directe, les caractéristiques du spray de carburant influent directement sur le rendement et les émissions. Les performances des modèles de spray existants et leur influence sur la combustion pour les moteurs Diesel et essence à injection directe sont analysées. Un modèle phénoménologique d'écoulement dans les injecteurs indiquant les effets de la géométrie sur les processus d'injection est présenté. Ce modèle donne les

  15. Spray Atomization Models in Engine Applications, from Correlations to Direct Numerical Simulations Modèles de spray dans les applications moteur, des corrélations aux simulations numériques directes

    Directory of Open Access Journals (Sweden)

    Dos Santos F.

    2011-09-01

    Full Text Available Sprays are among the very main factors of mixture formation and combustion quality in almost every (IC engine. They are of great importance in pollutant formation and energy efficiency although adequate modeling is still on development. For many applications, validation and calibration of models are still an open question. Therefore, we present an overview of existing models and propose some trends of improvement. Models are classified in zero dimensional and dimensional classes ranging from simple formulations aimed at close-to-real-time applications to complete detailed description of early atomization stages. Les sprays sont parmi les principaux facteurs de qualite, dans la formation du melange et la combustion, dans un grand nombre de moteurs (a combustion interne. Ils sont de toute premiere importance dans la formation de polluants et l’efficacite energetique, bien qu’une modelisation adequate soit encore en developpement. Pour un grand nombre d’applications, la validation et la calibration de ces modeles demeurent une question ouverte. Aussi, presentons-nous un apercu des modeles existants et proposons quelques voies d’amelioration. Les modeles sont classes en nondimensionnels et dimensionnels allant de formules simples dediees a des applications proches du temps reel a des descriptions detaillees des premiers stades de l’atomisation.

  16. Microstructural characterization and model of hardening for the irradiated austenitic stainless steels of the internals of pressurized water reactors; Caracterisation microstructurale et modelisation du durcissement des aciers austenitiques irradies des structures internes des reacteurs a eau pressurisee

    Energy Technology Data Exchange (ETDEWEB)

    Pokor, C

    2003-07-01

    The core internals of Pressurized Water Reactors (PWR) are composed of SA 304 stainless steel plates and CW 316 stainless steel bolts. These internals undergo a neutron flux at a temperature between 280 deg C and 380 deg C which modifies their mechanical properties. These modifications are due to the changes in the microstructure of these materials under irradiation which depend on flux, dose and irradiation temperature. We have studied, by Transmission Electron Microscopy, the microstructure of stainless steels SA 304, CW 316 and CW 316Ti irradiated in a mixed flux reactor (OSIRIS at 330 deg C between 0,8 dpa et 3,4 dpa) and in a fast breeder reactor at 330 deg C (BOR-60) up to doses of 40 dpa. Moreover, samples have been irradiated at 375 deg C in a fast breeder reactor (EBR-II) up to doses of 10 dpa. The microstructure of the irradiated stainless steels consists in faulted Frank dislocation loops in the [111] planes of austenitic, with a Burgers vector of [111]. It is possible to find some voids in the solution annealed samples irradiated at 375 deg C. The evolution of the dislocations loops and voids has been simulated with a 'cluster dynamic' model. The fit of the model parameters has allowed us to have a quantitative description of our experimental results. This description of the microstructure after irradiation was coupled together with a hardening model by Frank loops that has permitted us to make a quantitative description of the hardening of SA 304, CW 316 and CW 316Ti stainless steels after irradiation at a certain dose, flux and temperature. The irradiation doses studied grow up to 90 dpa, dose of the end of life of PWR internals. (author)

  17. Dolomitization of carbonated reservoirs of platforms. From geologic data to modeling. Example of the great Bahama bank; La dolomitisation des reservoirs carbonates de plate-forme. Des donnees geologiques a la modelisation. Exemple du Grand Banc des Bahamas

    Energy Technology Data Exchange (ETDEWEB)

    Caspard, E.

    2002-09-01

    Dolomitization has long been one of the most studied geological processes because of its economic interest (dolomitic rocks form a significant share of hydrocarbon reservoirs) as well as its academic interest, based on the fact that dolomite scarcely forms in current and recent marine environments whereas seawater is highly over-saturated; and that it is still not possible to synthesize it in laboratory under the same conditions. We used data collected by the University of Miami (Bahamas Drilling Project, ODP Leg 166) to understand the geological context of complete dolomitization of a Messinian 60 m thick reef unit. Classical methods of petrographic analysis of thin sections (optical microscopy, cathodoluminescence, scanning electron microscopy, in situ isotopic analyze using ionic microprobe) showed that the intensity of dolomitization is not controlled by the initial texture of the sediment, that the key parameter for dolomitization is the conservation of the initial mineralogy of magnesian bio-clasts, and that redox conditions, salinity and/or temperature of the precipitation fluid varied significantly during the process. Hydrodynamic modelling showed that during periods of high sea-level, Kohout thermal convection is a viable mechanism for driving marine fluids through the sediments. The key parameter for fluid circulations is the permeability anisotropy on the platform scale. Geochemical modelling showed that seawater is able to induce a complete dolomitization over durations of around one million years. Sensitivity tests showed that the critical parameter (as well as one of the less well-known) to describe diagenetic processes in carbonates is the water/rock reactions kinetics and in particular the precipitation kinetics of carbonate minerals. We finally propose that the dolomitization of the reef unit of the Unda well took place during the high sea-level period which extended over 1,1 My in the early Pliocene, according to the Kohout thermal convection

  18. Le role du phytoplancton de petite taille (<20 mum) dans les variations des proprietes optiques des eaux du Saint-Laurent

    Science.gov (United States)

    Mas, Sebastien

    Les mesures satellitaires de couleur des oceans sont largement determinees par les proprietes optiques inherentes (IOPs) des eaux de surface. D'autre part, le phytoplancton de petite taille (la contribution du phytoplancton (la variabilite des proprietes optiques observee en milieu naturel. D'autres experiences ont, quant a elles, mis en evidence que les variations des proprietes optiques des cellules phytoplanctoniques dues aux phases de croissance peuvent alterer les IOPs des oceans, particulierement pendant les periodes de floraison. De plus, la presence de bacteries et de particules detritiques peut egalement affecter la variabilite des IOPs totales, notamment la diffusion. Au printemps, dans l'Estuaire et le Golfe du Saint-Laurent, la contribution du phytoplancton la variabilite spatiale, les proprietes optiques cellulaires presentaient des variations journalieres, et ce particulierement pour le picophytoplancton. Enfin, la plupart des differences observees dans les proprietes biooptiques, particulierement l'absorption, etaient attribuables a la contribution du phytoplancton la structure de taille des communautes phytoplanctoniques dans les modeles bio-optiques appliques au Saint-Laurent. L'ensemble des resultats a permis de mettre en evidence l'importance des mecanismes de photoacclimatation et de synchronisation du cycle cellulaire du phytoplancton sur les variations journalieres des IOPs, ainsi que de l'etat physiologique relie au stade de croissance sur les variations temporelles a long terme des IOPs. De plus, le phytoplancton la variabilite des IOPs des oceans.

  19. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    37. Taux des lipides et des protéines et composition en acides gras du tissu comestible des crustacés et des mollusques pêchés en Algérie : Effet du halofénozide (RH-0345) sur la composition en acides gras de. Penaeus kerathurus (Crustacé, Décapode). Samira Gheid. 1. , Safia Nadji. 2 et Mohamed El Hadi Khebbeb. 3.

  20. Methoden Des Fremdsprachenunterrichts

    Directory of Open Access Journals (Sweden)

    Rasa Sklizmantaitė

    2011-04-01

    Full Text Available Beim Unterrichten einer Fremdsprache ist es wichtig, Methoden des Fremdsprachenunterrichts zu kennen, um eine Methode des Unterrichts nach dem Niveau und Bedürfnissen der entsprechenden Gruppe opti-mal zu wählen. Im Artikel wird der Überblick des Fremdsprachenunterrichts im Hinblick auf historische Entwicklung dargeboten sowie die Hauptmerkmale einiger Methoden des Fremdsprachenunterrichts aufgezählt.

  1. Des racines et des ailes

    Directory of Open Access Journals (Sweden)

    Stéphanie Vincent-Geslin

    2012-05-01

    Full Text Available Les mobilités pendulaires semblent être en augmentation en Europe depuis une dizaine d’années. Cette croissance du temps passé à se déplacer amène à remettre en question la conjecture de Zahavi et apparaît relativement inexplicable en regard du paradigme classique de l’acteur rationnel traditionnellement utilisé dans le champ des transports. Si, dans la littérature, les temps de déplacements sont principalement expliqués par le contexte résidentiel, la forme urbaine et le travail, ce cadre explicatif ne dit rien des processus de décision eux-mêmes qui amènent aux pendularités intensives.À partir d’une enquête qualitative menée auprès de pendulaires français, suisses et belges, cette contribution propose d’analyser les arbitrages et les éléments déterminants des processus de la grande pendularité. Les mobilités quotidiennes pendulaires apparaissent comme le résultat de compromis entre activité professionnelle, attachement résidentiel et choix de vie et prennent ainsi la forme de stratégies de conciliation entre vie privée et vie professionnelle. Ces mobilités spatiales permettent alors paradoxalement la préservation des ancrages résidentiels, sociaux et familiaux.Roots and wings. Long-distance commuting patterns, or how to conciliate professional and personal lifeLong-distance commuting patterns appear to be increasing in Europe over the last ten years. These raising mobility patterns lead to reappraise the Zahavi conjecture and appear largely inexplicable by the classical rational actor paradigm traditionally used in transportation research. In literature, commuting is mainly explained by residential contexts, urban forms and job. Nevertheless this theoretical frame says little about the decision-making processes themselves. Based on a qualitative survey conducted in three European countries - France, Belgium and Switzerland – among a population of high commuters, this paper proposes an analysis of

  2. Civili, langue des Baloango

    DEFF Research Database (Denmark)

    Mavoungou, Paul Achille; Ndinga-Koumba-Binza, Hugues Steve

    , Congo, Angola, etc.) issus de la décolonisation. Il présente de façon succincte quelques phénomènes historiques, phonologiques, morphosyntaxiques, homonymiques et analogiques de la langue. Des faits sémantiques des emprunts linguistiques y sont également décrits dans le cadre des changements...

  3. ANALYSE DES PERCEPTIONS LOCALES ET DES FACTEURS ...

    African Journals Online (AJOL)

    AISA

    haies vives) et la valorisation des produits forestiers tels que l'utilisation des tourteaux comme engrais organiques (Francis et al.,. 2005). Plusieurs études ont montré que les perceptions paysannes d'une technologie ou d'une innovation sont déterminantes pour son adoption. (Adesina et Baidu-forson, 1996). Les travaux.

  4. Elaboration of global quality standards for the thermal design of buildings in the french tropical islands; Elaboration d'un label de conception thermique des batiments dans les departements d'outremer francais

    Energy Technology Data Exchange (ETDEWEB)

    Garde, F.; Boyer, H. [Universite de la Reunion (France). Laboratoire de Genie Industriel; Celaire, R.

    2000-04-01

    Electric load profiles of tropical islands in developed countries are characterised by morning, midday and evening peaks arising from all year round high power demand in the commercial and residential sectors, mostly due to air conditioning appliances and bad thermal conception of the building. In early 1995, a DSM pilot initiative has been launched in the french islands of Guadeloupe and Reunion through a partnership between the French Public Utility EDF, institutions involved in energy conservation, environment preservation (ADEME) and construction quality improvement, the University of Reunion Island and several other public and private partners (low cost housing institutions, architects, energy consultant, etc..). To solve this problem, the work presented in this paper has led to the conception of a global quality standards obtained through optimized bio-climatic urban planning and architectural design, the use of passive cooling architectural components, natural ventilation and energy efficient systems such as solar water heaters. We evaluated, with the aid of an airflow and thermal building simulation software (CODYRUN), the impact of each technical solution on thermal comfort within the building. These technical solution have been implemented in 300 new pilot dwelling projects through the year 1996 in Reunion island and in Guadeloupe island. An experimental follow up is still in process in the first ECODOM dwellings to validate experimentally the impact of the passive cooling solutions on the comfort of the occupants and to modify them if necessary. (authors)

  5. Catalog and history of the experiments of criticality Saclay (1958-1964) Valduc / Building 10 (1964-2003); Catalogue et historique des experiences de criticite Saclay (1958 - 1964) Valduc / Batiment 10 (1964-2003)

    Energy Technology Data Exchange (ETDEWEB)

    Poullot, G.; Dumont, V.; Anno, J.; Cousinou, P. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Fontenay aux Roses (France); Grivot, P.; Girault, E.; Fouillaud, P.; Barbry, F. [CEA Valduc, 21 - Is-sur-Tille (France)

    2003-07-01

    The group ' International Criticality Safety Evaluation Benchmark evaluation project ' (I.C.S.B.E.P.) has for aim to supply to the international community experiments of benchmarks criticality, of certified quality, used to guarantee the qualification of criticality calculation codes. Have been defined: a structure of experiments classification, a format of standard presentation, a structure of work with evaluation, internal and external checks, presentation in plenary session. After favourable opinion of the work group, the synthesis document called evaluation is integrated to the general report I.C.S.B.E.P. (N.C.)

  6. Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

    Science.gov (United States)

    Amrani, Salah

    fabriquees industriellement. Cette technique a consiste a determiner le profil des differentes proprietes physiques. En effet, la methode basee sur la mesure de la distribution de la resistivite electrique sur la totalite de l'echantillon est la technique qui a ete utilisee pour localiser la fissuration et les macro-pores. La microscopie optique et l'analyse d'image ont, quant a elles, permis de caracteriser les zones fissurees tout en determinant la structure des echantillons analyses a l'echelle microscopique. D'autres tests ont ete menes, et ils ont consiste a etudier des echantillons cylindriques d'anodes de 50 mm de diametre et de 130 mm de longueur. Ces derniers ont ete cuits dans un four a UQAC a differents taux de chauffage dans le but de pouvoir determiner l'influence des parametres de cuisson sur la formation de la fissuration dans ce genre de carottes. La caracterisation des echantillons d'anodes cuites a ete faite a l'aide de la microscopie electronique a balayage et de l'ultrason. La derniere partie des travaux realises a l'UQAC contient une etude sur la caracterisation des anodes fabriquees au laboratoire sous differentes conditions d'operation. L'evolution de la qualite de ces anodes a ete faite par l'utilisation de plusieurs techniques. L'evolution de la temperature de refroidissement des anodes crues de laboratoire a ete mesuree; et un modele mathematique a ete developpe et valide avec les donnees experimentales. Cela a pour objectif d'estimer la vitesse de refroidissement ainsi que le stress thermique. Toutes les anodes fabriquees ont ete caracterisees avant la cuisson par la determination de certaines proprietes physiques (resistivite electrique, densite apparente, densite optique et pourcentage de defauts). La tomographie et la distribution de la resistivite electrique, qui sont des techniques non destructives, ont ete employees pour evaluer les defauts internes des anodes. Pendant la cuisson des anodes de laboratoire, l'evolution de la resistivite

  7. Appropriation des Tic et performance des entreprises

    OpenAIRE

    Lethiais , Virginie; Smati , Wided

    2009-01-01

    Quatre pages Marsouin; L'utilisation des TIC (Technologies de l'information et de la Communication) se développe dans les entreprises pour assurer des tâches de plus en plus nombreuses : la communication, la recherche d'informations, la commercialisation des produits et services, le travail en groupe, la gestion de l'entreprise, la prospection, etc. Les équipements en TIC ainsi que l'usage qui en est fait diffèrent d'une entreprise à une autre selon de nombreux critères. L'objet de ce quatre ...

  8. Evolution des modèles mathématiques directs appliqués aux moteurs à combustion interne Evolution of Direct Mathematical Models Applied to Internal-Combustion Engines

    Directory of Open Access Journals (Sweden)

    Rumiano N.

    2006-11-01

    Full Text Available Cet article rend compte de l'évolution présente et future des modèles mathématiques directs de simulation dans les moteurs. Ceux-ci sont basés sur la résolution des équations de Navier-Stokes, et deviennent peu à peu une nécessité surtout en ce qui concerne la combustion hétérogène. Après un aperçu sur l'état actuel des algorithmes de calcul et des sous-modèles physiques utilisés, on présente une revue des principaux codes de calcul appliqués au moteur, avec quelques-uns de leurs résultats. Après avoir évoqué les obstacles rencontrés lors de leur mise en oeuvre, on aborde l'évolution prévisible lors des prochaines années, tant pour les techniques de calcul que pour les codes eux-mêmes. This article describes the present and future evolution of direct mathematical models used for engine simulation. These models are based on the solving of Navier-Stokes equations and are gradually becoming an absolute necessity, especially with regard to heterogeneous combustion. Alter briefly describing the present state of the computing algorithms and physical submodels used, the leading computing codes applied to engines are reviewed, with some of their results. Then the stumbling blocks encountered during the implementation of these codes are described, followed by the foresable evolution in the next few years, for both computing techniques and the codes themselves.

  9. Modelization des consequences possibles de la future demande bioenergetique mondiale pour le bois et les forest en France

    Science.gov (United States)

    Joseph Buongiorno; Ronald Raunikar; Shushuai Zhu

    2011-01-01

    L’article présente une exploration, menée au moyen d’un modèle mondial de la filière-bois, de l’effet sur la filière-bois française des modifications actuelles et prévisibles de la demande mondiale en énergie issue de la biomasse. Deux scénarios contrastés sont testés. Les résultats sont mis en perspective et soulignent le conflit potentiel entre usages du bois : bois...

  10. Un modele simple de simulation des relations microclimat-bilan carbone chez la tomate en phase vegetative

    OpenAIRE

    Gary, C.

    1988-01-01

    Un modèle simple simulant la réponse au microclimat (rayonnement, température) des différents termes du bilan carboné de plantes entières de tomate en phase végétative est proposé. Il prend en compte l’existence de réserves glucidiques et leur effet tampon entre photosynthèse et croissance. Il s’appuie sur les hypothèses suivantes : (a) l’activité respiratoire est déterminée essentiellement par la quantité de substrat glucidique disponible et par la température ; (b) la croissance est lim...

  11. Multi-Dimensional Modeling of Combustion and Pollutants Formation of New Technology Light Duty Diesel Engines Modélisation multidimensionnelle de la combustion et de la formation des polluants dans les nouveaux moteurs diesel automobiles

    Directory of Open Access Journals (Sweden)

    Belardini P.

    2006-12-01

    Full Text Available In the present paper some results, obtained by the use of modern numerical CFD tools, are presented. In particular, starting from the experimental characterization of a common rail DI Diesel engine, the empirical constants of the different submodels were tuned to obtain satisfactory results in some key test conditions. The main constraints of numerical models, to obtain a right scaling of pollutants predictions in the different test cases are analyzed. The numerical analysis demonstrates that the numerical CFD tools, at their stage of development, can help the engine designers to define the more promising strategies to obtain tailpipe emission control of common rail Diesel DI engines. Dans cet article, nous présentons les résultats obtenus en utilisant des outils de simulation de la mécanique des fluides numérique (CFD. À partir de résultats expérimentaux issus de la caractérisation d'un moteur Diesel common rail, les constantes empiriques de divers modèles ont été ajustées afin d'obtenir des résultats satisfaisants pour des cas tests représentatifs. Les principales contraintes des modèles numériques pour obtenir une bonne précision dans les différents cas d'études sont ici analysées. Cette analyse numérique montre que la CFD permet déjà, au stade de développement atteint, d'aider les ingénieurs à définir les stratégies les plus prometteuses pour maîtriser les émissions à l'échappement des moteurs Diesel à injection common rail.

  12. Cartographie des directions dominantes des vents au Benin : Outil ...

    African Journals Online (AJOL)

    Cartographie des directions dominantes des vents au Benin : Outil de conception et de dimensionnement des ouvrages. ... nous avons, après la collecte des informations météorologiques, procédé : - à l'analyse des données (directions) des six stations météorologiques principales conformément aux méthodes statistiques.

  13. Analyse de l'évolution et modélisation des besoins énergétiques français. Application du modèle ABEL à des scénarios contrastés aux horizons 2000 et 2020 Evolutionary Analysis and Modeling of French Energy Needs. Applying the ABEL Model to Contrasting Scenarios for the Horizons 2000 and 2020

    Directory of Open Access Journals (Sweden)

    Roncato J. P.

    2006-11-01

    Full Text Available Devant l'enchérissement du pétrole, les pays industrialisés à faibles ressources énergétiques fossiles nationales devront recourir dans le futur à d'autres formes d'énergie (nucléaire, charbon, solaire. La transformation de ces énergies primaires en vecteurs commercialisables est caractérisée par des coûts d'investissement élevés. Cela impose de rechercher le meilleur taux d'utilisation des équipements face à une demande fortement modulée. L'étude de tels systèmes énergétiques procède en deux étapes : analyse des besoins en énergie, puis optimisation des équipements depuis le niveau de production jusqu'à l'utilisation. L'objet de cette communication est de présenter un modèle d'étude de la consommation (ABEL, qui s'appuie sur une analyse du système socio-économique national expliquant la formation et l'évolution des besoins d'énergie. Cette analyse aboutit à la construction de modèles de simulation des consommations d'énergie par secteur. Cette modélisation rend compte des variations saisonnières des besoins. Un modèle macro-économique de cohérence traduit les relations entre niveaux d'activité des différents secteurs, de façon à éviter des distorsions grossières dans une projection à long terme. Des scénarios permettent de simuler diverses hypothèses de développement économique et social. Faced with increasing oil prices, the industrialized countries with smail national fossil energy resources will have to look to other types of energy in the future (nuclear energy, coal, solar energy. The transformation of such primary energy sources into marketable carriers is characterized by high investment costs. This means that the best utilization factor for equipment will have to be sought after in the face of highly modulated demand. A survey of such energy systems is made in two steps: (a analyzing energy needs, and (b optimizing equipment all the way from initial production to end use. The aim of

  14. Applications biotechnologiques des mycorhizes

    OpenAIRE

    Redecker, Dirk

    2012-01-01

    La symbiose mycorhizienne est une association entre un champignon mycorhizogène et une racine de plante-hôte. La mycorrhize à arbuscules (MA) est extrêmement ancienne puisqu’elle est datée de la même époque que l’apparition des plantes terrestres, il y a 460 millions d’années. Elle s’effectue entre un champignon mycorhizogène à arbuscules (CMA, phylum Glomeromycota) et plus de 80% des plantes terrestres. Les CMA sont des microorganismes ubiquitaires du sol et sont des biotrophes obligatoires ...

  15. Gestion des risques

    CERN Document Server

    Louisot, Jean-Paul

    2009-01-01

    Depuis le début du lie siècle, la gestion des risques connaît une véritable révolution culturelle. Jusqu'alors fonction technique, centrée autour de l'achat de couverture d'assurances, elle est devenue une discipline managériale et transversale : une valise d'instruments que chaque manager doit connaître et appliquer quels que soient son domaine de compétence et ses missions au sein de l'organisation. En effet, la gestion des risques est une culture qui doit être assimilée par chacun des acteurs. C'est précisément l'ambition des 101 questions rassemblées dans cet ouvrage : apporter à chaque manager d'entreprise, de collectivité, d'établissement de santé..., des réponses claires au " pourquoi " et au " comment " : Comment identifier les risques ? Comment analyser les risques ? Quels sont les objectifs de la gestion des risques ? Une carte des risques pour quoi faire ? Pourquoi faut-il financer les risques ? Les entreprises ont-elles des responsabilités pénales ? En quoi consiste la gestion...

  16. La gouvernance des risques naturels et la problematique des ...

    African Journals Online (AJOL)

    Depuis quelques années, la gouvernance des risques naturels dus aux inondations remet en cause les processus de mise en oeuvre des politiques urbaines et la qualité de la structure des aménagements dans les grandes villes du Golfe de Guinée. La perception de la gouvernance et l'application des politiques de ...

  17. Modelling of the spallation reaction: analysis and testing of nuclear models; Simulation de la spallation: analyse et test des modeles nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Toccoli, C

    2000-04-03

    The spallation reaction is considered as a 2-step process. First a very quick stage (10{sup -22}, 10{sup -29} s) which corresponds to the individual interaction between the incident projectile and nucleons, this interaction is followed by a series of nucleon-nucleon collisions (intranuclear cascade) during which fast particles are emitted, the nucleus is left in a strongly excited level. Secondly a slower stage (10{sup -18}, 10{sup -19} s) during which the nucleus is expected to de-excite completely. This de-excitation is performed by evaporation of light particles (n, p, d, t, {sup 3}He, {sup 4}He) or/and fission or/and fragmentation. The HETC code has been designed to simulate spallation reactions, this simulation is based on the 2-steps process and on several models of intranuclear cascades (Bertini model, Cugnon model, Helder Duarte model), the evaporation model relies on the statistical theory of Weiskopf-Ewing. The purpose of this work is to evaluate the ability of the HETC code to predict experimental results. A methodology about the comparison of relevant experimental data with results of calculation is presented and a preliminary estimation of the systematic error of the HETC code is proposed. The main problem of cascade models originates in the difficulty of simulating inelastic nucleon-nucleon collisions, the emission of pions is over-estimated and corresponding differential spectra are badly reproduced. The inaccuracy of cascade models has a great impact to determine the excited level of the nucleus at the end of the first step and indirectly on the distribution of final residual nuclei. The test of the evaporation model has shown that the emission of high energy light particles is under-estimated. (A.C.)

  18. Relations de Dispersion et Diffusion des Glueballs et des Mesons dans la Theorie de Jauge U(1)(2+1) Compacte

    Science.gov (United States)

    Ahmed, Chaara El Mouez

    Nous avons etudie les relations de dispersion et la diffusion des glueballs et des mesons dans le modele U(1)_{2+1} compact. Ce modele a ete souvent utilise comme un simple modele de la chromodynamique quantique (QCD), parce qu'il possede le confinement ainsi que les etats de glueballs. Par contre, sa structure mathematique est beaucoup plus simple que la QCD. Notre methode consiste a diagonaliser l'Hamiltonien de ce modele dans une base appropriee de graphes et sur reseau impulsion, afin de generer les relations de dispersion des glueballs et des mesons. Pour la diffusion, nous avons utilise la methode dependante du temps pour calculer la matrice S et la section efficace de diffusion des glueballs et des mesons. Les divers resultats obtenus semblent etre en accord avec les travaux anterieurs de Hakim, Alessandrini et al., Irving et al., qui eux, utilisent plutot la theorie des perturbations en couplage fort, et travaillent sur un reseau espace-temps.

  19. Evaluation of the nuclear cross section variance-covariance matrices issued from the nuclear optical model; Evaluation des matrices de variance-covariance des sections efficaces nucleaires issues du modele optique

    Energy Technology Data Exchange (ETDEWEB)

    Brassart, M. [Ecole Nationale Superieure Ingenieurs de Bourges, 18 - Bourges (France); Mounier, C. [CEA Saclay, Dir. de l' Energie Nucleaire DEN, Service d' Etudes des Reacteurs et de Modelisation Avancee, 91 - Gif sur Yvette (France); Dossantos-Uzarralde, P. [CEA Bruyeres le Chatel, 91 (France). Dept. de Physique Theorique et Appliquee

    2004-07-01

    Nuclear reaction models play an important role in today's nuclear data evaluations. There are, however, difficulties associated with evaluating data uncertainties, both while performing the experimental measurements as well as constructing them by nuclear models. In this general context, our interest is particularly targeted towards the study of the propagation uncertainties within nuclear models. In this report we discuss two distinct ways of calculating the nuclear cross section variance-covariance matrices and then show these can be applied to the nuclear spherical optical model. (authors)

  20. Proprietes Adiabatiques des Naines Blanches Pulsantes de Type ZZ Ceti

    Science.gov (United States)

    Brassard, Pierre

    1992-01-01

    Cette these a pour but d'etudier les proprietes des oscillation non-radiales des etoiles ZZ Ceti, appelees aussi etoiles DA variables, dans le contexte de la theorie adiabatique des petites oscillations. Ces oscillations sont observables, pour ce type d'etoiles, sous forme de variations periodiques de la luminosite. A partir d'une analyse de modeles stellaires, analyse qui consiste principalement a calculer et a interpreter les periodes d'oscillations des modeles, nous voulons mieux connai tre les proprietes physiques fondamentales des ZZ Ceti. Nous developpons tout d'abord divers outils pour entreprendre cette etude. Apres avoir presente le formalisme mathematique de base decrivant les oscillations non-radiales d'une etoile, nous discutons des difficultes pouvant etre rencontrees dans le calcul de la frequence de Brunt-Vaisala, une quantite fondamentale pour le calcul des periodes d'oscillations. Par la suite, nous developpons un modele theorique simple permettant d'analyser et d'interpreter la structure des periodes calculees (ou observees) en termes des proprietes de structure de l'etoile. Nous presentons aussi les outils numeriques tout a fait originaux utilises pour calculer nos periodes a partir de modeles stellaires. Finalement, nous presentons les resultats d'ensemble de l'analyse de nos modeles, et discutons de l'interpretation des observations de periodes et du taux de variation de ces periodes en termes de structure de l'etoile et de composition du noyau de l'etoile, respectivement. Ces resultats representent l'etude la plus complete a ce jour de la seismologie des naines blanches.

  1. Calcul des paramètres de l'équation de Wilson. Analyse comparative des représentations d'équilibres liquide-vapeur isothermes par les modèles de Wilson et NRTL Computing Parameters in the Wilson Equation. Comparatrice Analysis of Representations of Isothermal Liquid-Vapor Equilibria by Wilson and Nrtl Models

    Directory of Open Access Journals (Sweden)

    Desplanches H.

    2006-11-01

    Full Text Available Un programme de calcul des paramètres de l'équation de Wilson est mis au point. II utilise une méthode itérative de minimisation des écarts sur la pression et la composition de vapeur ou sur chaque grandeur prise séparément. Les méthodes utilisées sont testées sur neuf équilibres liquide-vapeur isothermes de mélanges binaires à déviations positives ou négatives. Les écarts moyens entre les valeurs expérimentales : - de la pression; - de la composition de la vapeur; - de l'enthalpie libre d'excès; et les valeurs calculées à partir des paramètres de Wilson sont comparés à ceux obtenus d'après le modèle NRTL. A program has been developed for computing the parameters in the Wilson equation. It uses an iterative method of minimizing the differences in pressure and steam composition or in each magnitude token separately. The methods used are tried out on nine isothermal liquid-vapor equilibria of binary mixtures with positive or negative deviations. The mean differences between experimental values of the : - pressure; - vapor composition; - excess free enthalpy; and values computed from Wilson parameters are compared with those obtained from an NRTL model.

  2. Modelling the Dynamics of Post-Vaccination Immunity Rate in a Population of Sahelian Sheep after a Vaccination Campaign against Peste des Petits Ruminants Virus

    Science.gov (United States)

    Lancelot, Renaud; Lesnoff, Matthieu

    2016-01-01

    Background Peste des petits ruminants (PPR) is an acute infectious viral disease affecting domestic small ruminants (sheep and goats) and some wild ruminant species in Africa, the Middle East and Asia. A global PPR control strategy based on mass vaccination—in regions where PPR is endemic—was recently designed and launched by international organizations. Sahelian Africa is one of the most challenging endemic regions for PPR control. Indeed, strong seasonal and annual variations in mating, mortality and offtake rates result in a complex population dynamics which might in turn alter the population post-vaccination immunity rate (PIR), and thus be important to consider for the implementation of vaccination campaigns. Methods In a context of preventive vaccination in epidemiological units without PPR virus transmission, we developed a predictive, dynamic model based on a seasonal matrix population model to simulate PIR dynamics. This model was mostly calibrated with demographic and epidemiological parameters estimated from a long-term follow-up survey of small ruminant herds. We used it to simulate the PIR dynamics following a single PPR vaccination campaign in a Sahelian sheep population, and to assess the effects of (i) changes in offtake rate related to the Tabaski (a Muslim feast following the lunar calendar), and (ii) the date of implementation of the vaccination campaigns. Results The persistence of PIR was not influenced by the Tabaski date. Decreasing the vaccination coverage from 100 to 80% had limited effects on PIR. However, lower vaccination coverage did not provide sufficient immunity rates (PIR vaccination campaigns in September-October. This model is a first step towards better decision support for animal health authorities. It might be adapted to other species, livestock farming systems or diseases. PMID:27603710

  3. Construction and validation of detailed kinetic models for the combustion of gasoline surrogates; Construction et validation de modeles cinetiques detailles pour la combustion de melanges modeles des essences

    Energy Technology Data Exchange (ETDEWEB)

    Touchard, S.

    2005-10-15

    The irreversible reduction of oil resources, the CO{sub 2} emission control and the application of increasingly strict standards of pollutants emission lead the worldwide researchers to work to reduce the pollutants formation and to improve the engine yields, especially by using homogenous charge combustion of lean mixtures. The numerical simulation of fuel blends oxidation is an essential tool to study the influence of fuel formulation and motor conditions on auto-ignition and on pollutants emissions. The automatic generation helps to obtain detailed kinetic models, especially at low temperature, where the number of reactions quickly exceeds thousand. The main purpose of this study is the generation and the validation of detailed kinetic models for the oxidation of gasoline blends using the EXGAS software. This work has implied an improvement of computation rules for thermodynamic and kinetic data, those were validated by numerical simulation using CHEMKIN II softwares. A large part of this work has concerned the understanding of the low temperature oxidation chemistry of the C5 and larger alkenes. Low and high temperature mechanisms were proposed and validated for 1 pentene, 1-hexene, the binary mixtures containing 1 hexene/iso octane, 1 hexene/toluene, iso octane/toluene and the ternary mixture of 1 hexene/toluene/iso octane. Simulations were also done for propene, 1-butene and iso-octane with former models including the modifications proposed in this PhD work. If the generated models allowed us to simulate with a good agreement the auto-ignition delays of the studied molecules and blends, some uncertainties still remains for some reaction paths leading to the formation of cyclic products in the case of alkenes oxidation at low temperature. It would be also interesting to carry on this work for combustion models of gasoline blends at low temperature. (author)

  4. Modelling and numerical simulation of the General Dynamic Equation of aerosols; Modelisation et simulation des aerosols atmospheriques

    Energy Technology Data Exchange (ETDEWEB)

    Debry, E.

    2005-01-15

    Chemical-transport models are now able to describe in a realistic way gaseous pollutants behavior in the atmosphere. Nevertheless atmospheric pollution also exists as fine suspended particles, called aerosols, which interact with gaseous phase, solar radiation, and have their own dynamic behavior. The goal of this thesis is the modelling and numerical simulation of the General Dynamic Equation of aerosols (GDE). Part I deals with some theoretical aspects of aerosol modelling. Part II is dedicated to the building of one size resolved aerosol model (SIREAM). In part III we perform the reduction of this model in order to use it in dispersion models as POLAIR3D. Several modelling issues are still opened: organic aerosol matter, externally mixed aerosols, coupling with turbulent mixing, and nano-particles. (author)

  5. Structured modeling of systems using bond graphs (Automation); Modelisation structuree des systemes avec les bond graphs (automatique)

    Energy Technology Data Exchange (ETDEWEB)

    Verge, M.; Jaume, D.

    2004-10-01

    The creation of new products requires the knowledge of the physical phenomena involved. Starting from models difficult to design, simple simulations are necessary before the first realizations. This book explains the modeling of dynamical systems from different technologies: mechanical, hydraulic, electric, thermal. The proposed modeling is based on the bond graph approach which is characterized by power conservation. This approach allows to design the model as the encapsulation of several elementary models exchanging energy. The efficiency of softwares and the need of model libraries have contributed to the fast spreading of this method in the industry. After a theoretical first part, the second part of the book presents some industrial examples where the design of models is integrally detailed and for which simulations have been performed. (J.S.)

  6. Photonique des Morphos

    CERN Document Server

    Berthier, Serge

    2010-01-01

    La photonique est déjà présente dans notre vie quotidienne, et on attend maintenant que la manipulation des photons permette aussi le traitement logique des informations. Cependant, l’élément de base qui permet cette manipulation de la lumière, le cristal photonique, est d’une réalisation complexe et mal contrôlée. Dans la course à la maîtrise de la lumière, les structures photoniques naturelles ont beaucoup à nous apprendre. C’est ce que nous montre Serge Berthier qui étudie dans ce livre la structure des écailles des Morphos. Tenant compte de l’essor récent des approches biomimétiques, il présente de manière détaillée plus de dix-huit techniques expérimentales utilisées pour ses analyses, ainsi que les diverses approches théoriques développées pour la modélisation de structures multi-échelles complexes. Première étude quasi-exhaustive des structures fines d’un genre et des propriétés optiques ainsi que colorimétriques générées, ce livre fournit aux entomologiste...

  7. Droit des organisations internationales

    CERN Document Server

    Sorel, Jean-Marc; Ndior, Valère

    2013-01-01

    Cet ouvrage collectif offre aux enseignants et chercheurs en droit international, aux praticiens et aux étudiants, une analyse actualisée du droit des organisations internationales. Il dresse en cinq parties un tableau, illustré par des exemples variés, des problématiques que soulève le phénomène polymorphe d institutionnalisation de la société internationale. La première partie est consacrée au phénomène des « organisations internationales », sous l angle à la fois de l institutionnalisation progressive des relations internationales et de la difficulté à cerner une catégorie unifiée. La deuxième partie rend compte de la création, de la disparition et des mutations des organisations internationales, ici envisagées comme systèmes institutionnels et ordres juridiques dérivés. La troisième partie analyse l autonomie que l acquisition de la personnalité juridique et de privilèges et immunités, un organe administratif intégré, un personnel ou un budget propres confèrent aux organi...

  8. Unsteady Three-Dimensional Simulation of a Shear Coaxial GO2/GH2 Rocket Injector with RANS and Hybrid-RAN-LES/DES Using Flamelet Models

    Science.gov (United States)

    Westra, Doug G.; West, Jeffrey S.; Richardson, Brian R.

    2015-01-01

    Historically, the analysis and design of liquid rocket engines (LREs) has relied on full-scale testing and one-dimensional empirical tools. The testing is extremely expensive and the one-dimensional tools are not designed to capture the highly complex, and multi-dimensional features that are inherent to LREs. Recent advances in computational fluid dynamics (CFD) tools have made it possible to predict liquid rocket engine performance, stability, to assess the effect of complex flow features, and to evaluate injector-driven thermal environments, to mitigate the cost of testing. Extensive efforts to verify and validate these CFD tools have been conducted, to provide confidence for using them during the design cycle. Previous validation efforts have documented comparisons of predicted heat flux thermal environments with test data for a single element gaseous oxygen (GO2) and gaseous hydrogen (GH2) injector. The most notable validation effort was a comprehensive validation effort conducted by Tucker et al. [1], in which a number of different groups modeled a GO2/GH2 single element configuration by Pal et al [2]. The tools used for this validation comparison employed a range of algorithms, from both steady and unsteady Reynolds Averaged Navier-Stokes (U/RANS) calculations, large-eddy simulations (LES), detached eddy simulations (DES), and various combinations. A more recent effort by Thakur et al. [3] focused on using a state-of-the-art CFD simulation tool, Loci/STREAM, on a two-dimensional grid. Loci/STREAM was chosen because it has a unique, very efficient flamelet parameterization of combustion reactions that are too computationally expensive to simulate with conventional finite-rate chemistry calculations. The current effort focuses on further advancement of validation efforts, again using the Loci/STREAM tool with the flamelet parameterization, but this time with a three-dimensional grid. Comparisons to the Pal et al. heat flux data will be made for both RANS and

  9. Modelling Adsorption of Foam-Forming Surfactants Modélisation de l'adsorption des produits tensio-actifs moussants

    Directory of Open Access Journals (Sweden)

    Mannhardt K.

    2006-11-01

    Full Text Available There is considerable interest in the use of foam-forming surfactants for mobility control in gas flooding enhanced oil recovery processes. The success of any such process is strongly affected by the rate of propagation of the surfactant through the reservoir. A sound understanding of surfactant adsorption on rock surfaces at reservoir conditions is therefore essential. This paper describes a model for the evaluation of adsorption during flow of surfactant solutions through porous media. The adsorption term in the flow equation is expressed in terms of the surface excess which proves to be more generally applicable than, for example, the Langmuir adsorption isotherm. Adsorption isotherms of three types of commercially available foam-forming surfactants are determined from core flooding data at different temperatures and brine salinities. L'utilisation de produits tensio-actifs moussants pour le contrôle de mobilité dans les procédés de récupération assistée du pétrole par injection de gaz suscite actuellement un grand intérêt. Mais le succès d'un tel procédé dépend largement de la vitesse de propagation du tensioactif dans le réservoir. Il est donc indispensable d'avoir une bonne connaissance de l'adsorption du tensio-actif sur les surfaces de la roche, dans les conditions de réservoir. Cet article décrit un modèle qui permet d'évaluer l'adsorption pendant l'écoulement de solutions tensio-actives en milieu poreux. Le terme qui représente l'adsorption dans l'équation de l'écoulement est exprimé en fonction de l'excédent de surface, concept qui s'est révélé d'une application plus générale que, par exemple, l'isotherme d'adsorption de Langmuir. Les isothermes d'adsorption de trois types de tensio-actifs moussants disponibles sur le marché sont déterminées à partir de données obtenues lors d'essais de déplacement dans des carottes, à différentes températures et avec des saumures de différentes salinités.

  10. Analysis and modelling of the energy requirements of batch processes; Analyse und Modellierung des Energiebedarfes in Batch-Prozessen

    Energy Technology Data Exchange (ETDEWEB)

    Bieler, P.S.

    2002-07-01

    This intermediate report for the Swiss Federal Office of Energy (SFOE) presents the results of a project aiming to model the energy consumption of multi-product, multi-purpose batch production plants. The utilities investigated were electricity, brine and steam. Both top-down and bottom-up approaches are described, whereby top-down was used for the buildings where the batch process apparatus was installed. Modelling showed that for batch-plants at the building level, the product mix can be too variable and the diversity of products and processes too great for simple modelling. Further results obtained by comparing six different production plants that could be modelled are discussed. The several models developed are described and their wider applicability is discussed. Also, the results of comparisons made between modelled and actual values are presented. Recommendations for further work are made.

  11. Study of archaeological analogs for the validation of nuclear glass long-term behavior models; Etude d'analogues archeologiques pour la validation des modeles de comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Verney-Carron, A

    2008-10-15

    Fractured archaeological glass blocks collected from a shipwreck discovered in the Mediterranean Sea near Embiez Island (Var) were investigated because of their morphological analogy with vitrified nuclear waste and of a known and stable environment. These glasses are fractured due to a fast cooling after they were melted (like nuclear glass) and have been altered for 1800 years in seawater. This work results in the development and the validation of a geochemical model able to simulate the alteration of a fractured archaeological glass block over 1800 years. The kinetics associated with the different mechanisms (interdiffusion and dissolution) and the thermodynamic parameters of the model were determined by leaching experiments. The model implemented in HYTEC software was used to simulate crack alteration over 1800 years. The consistency between simulated alteration thicknesses and measured data on glass blocks validate the capacity of the model to predict long-term alteration. This model is able to account for the results from the characterization of crack network and its state of alteration. The cracks in the border zone are the most altered due to a fast renewal of the leaching solution, whereas internal cracks are thin because of complex interactions between glass alteration and transport of elements in solution (influence of initial crack aperture and of the crack sealing). The lowest alteration thicknesses, as well as their variability, can be explained. The analog behavior of archaeological and nuclear glasses from leaching experiments makes possible the transposition of the model to nuclear glass in geological repository. (author00.

  12. Terminologie des indices boursiers

    OpenAIRE

    Van der Yeught, Michel

    2013-01-01

    Les indices boursiers sont omniprésents en anglais financier. Les plus importants sont universellement familiers mais leur nature et leur fonctionnement restent largement méconnus. Des distinctions (average/index, narrow index/broad index, price-weighted/market value-weighted, all share/ composite/ subindex) permettront à l’angliciste de spécialité d’adapter à chaque indice la terminologie française ou anglaise qui lui correspond. Des remarques sur des erreurs courantes, un mini-glossaire, un...

  13. Application of cost mathematical models to the determination of investments in the petroleum industry; Application des modeles mathematiques de cout a la determination des investissements dans l`industrie petroliere

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, G.; Ecole Nationale Superieure du Petrole et des Moteurs (ENSPM), 92 -Rueil-Malmaison (France); Univ. de Bourgogne, 21- Dijon (France)

    1997-05-01

    It is today of paramount importance to realistically forecast the cost and time required to design and manufacture a given product, from the very first phase of the project. Furthermore, with the increasingly rapid development of technology, it is often impossible to draw a direct parallel with existing, well known products Mathematical models of cost, and MAP models in particular, have been developed to meet this need. Although one may still refer to former products, they do not automatically have to be `analogous` to the product under consideration, because these methods use `universal relationship` between cost, weight, technology, performance and reliability, and also the nature and experience of the firm manufacturing the product. The purpose of this thesis is to demonstrate the pertinence, and more importantly the potential, of mathematical models of cost for the oil and gas industry, from exploration and production to refining, petrochemicals, and internal combustion engines. After a theoretical examination of estimation methods and a classification of existing ones, emphasis is placed on the logical aspect of these models. In addition, the complementarity between these tools and certain fields such as project management is pointed out, for example with respect to value control. The last chapter of the thesis is devoted to case studies. It aims chiefly at comparing theory with practice in order to identify the limits of mathematical models of cost so that they can be used judiciously. (author). 159 refs.

  14. The multimedia models for the evaluation of exposure bond to the atmospheric emissions of classified installations; Les modeles multimedia pour l'evaluation des expositions liees aux emissions atmospheriques des installations classees

    Energy Technology Data Exchange (ETDEWEB)

    Bonnard, R

    2001-12-15

    Risk assessment and environmental impacts studies are realized to preserve the public health. Today one of the most used approach is the use of an atmospheric dispersion model to assess the risks. The data are then injected in a calculation software of exposure bond to polluted soils, to evaluate the risks of non direct exposure. This report details and evaluates the models corresponding to the need: the methodology for assessing Health Risks associated with multiple pathways of exposure to combustor, human health risk assessment proto col for hazardous waste combustion facilities, EUSES, CALTOX, MEPAS, MEND-TOX, RESRAD, MMSOILS, FRAMES-HWIR, PC-GEMS and TRIM. (A.L.B.)

  15. Strong explosions impact on buildings representative of an industrial facility; Impact de fortes explosions sur les batiments representatifs d'une installation industrielle

    Energy Technology Data Exchange (ETDEWEB)

    Trelat, S

    2006-12-15

    The goal of this study is to focus on the analysis of blast wave damage to structures when blast wave is consequence of explosive charge detonation. The objective is to propose useful tools to predict charges on structure. All experiences are realized in laboratory. The experimental investigation consists in simulating a detonation of a stoichiometric propane-oxygen mixture at ground level or at higher altitude. The study is going to give us experimental data on blast wave effects on a structure. For that, two types of structures frequently found on industrial site are going to be used: a parallelepipedal structure and a cylindrical structure, both with known dimensions. Finally, the important point of the problem is to determine an energetic equivalence between TNT and gas used in the experiments, in order to model TNT explosions at full scale by gaseous explosions at reduced scale. (author)

  16. Dental Encounter System (DES)

    Data.gov (United States)

    Department of Veterans Affairs — Dental Encounter System (DES) is an automated health care application designed to capture critical data about the operations of VA Dental Services. Information on...

  17. Die Wahrheit des Holocaust

    Directory of Open Access Journals (Sweden)

    Michael Stolleis

    2003-01-01

    Full Text Available Rezensiertes Werk: Raul Hilberg, Die Quellen des Holocaust. Entschlüsseln und Interpretieren. Deutsch von Udo Rennert, Frankfurt am Main: S. Fischer 2002, 256 S., ISBN 3-10-033626-7

  18. Modeling of pollution aerosols in Ile-de-France; Modelisation des aerosols de pollution en Ile-de-France

    Energy Technology Data Exchange (ETDEWEB)

    Hodzic, A

    2005-10-15

    The modeling of aerosols is a major stake in the understanding of the emission processes and evolution of particulates in the atmosphere. However, the parameterizations used in today's aerosol models still comprise many uncertainties. This work has been motivated by the need of better identifying the weaknesses of aerosols modeling tools and by the necessity of having new validation methods for a 3D evaluation of models. The studies have been carried out using the CHIMERE chemistry-transport model, which allows to simulate the concentrations and physico-chemical characteristics of pollution aerosols at the European scale and in Ile-de-France region. The validation approach used is based on the complementarity of the measurements performed on the ground by monitoring networks with those acquired during the ESQUIF campaign (study and simulation of air quality in Ile-de-France), with lidar and photometric measurements and with satellite observations. The comparison between the observations and the simulations has permitted to identify and reduce the modeling errors, and to characterize the aerosol properties in the vicinity of an urban area. (J.S.)

  19. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Key words: cathode sputtering magnetron; thin films; nanostructure; corrosion; alloys Fe-Si. 1. INTRODUCTION. Les alliages de fer–Silicium (FexSiy) sont des matériaux importants, largement répandus dans des circuits électroniques et magnétiques, et jouissent d‟un excellent rapport qualité/prix. Ce succès est lie aux.

  20. typologie des parcs agroforestiers

    African Journals Online (AJOL)

    AISA

    AU SENEGAL : TYPOLOGIE DES PARCS AGROFORESTIERS. I. COLY1, L. E. AKPO1, D. SARR1, R. MALOU2, H. DACOSTA3 et F. DIOME4. 1Faculté des Sciences et ... Mots clés : Agro-écologie, parcs agro forestiers, typologie, Bas fonds de la Néma, Sénégal. .... afin d'en distinguer les sous unités, et d'en établir.

  1. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    1 mai 2011 ... microscopie électronique à balayage (MEB) et la diffraction des rayons X (DRX). Nous avons effectué des essais d‟oxydation à haute température sur trois alliages binaires FeAl à 1 000 oC, dans une atmosphère d'air de laboratoire et à pression atmosphérique. Les essais d‟oxydation menés à 1000 °C ...

  2. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    déclin avec le développement de la chimie de synthèse, toutefois les effets indésirables des médicaments ont ravivé l‟intérêt des scientifiques pour les plantes médicinales. C‟est ainsi que de nouvelles recherches ont vu le jour, notamment de l‟espoir de traiter certaines maladies infectieuses par les huiles essentielles.

  3. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    profondes aux fosses abyssales représentant ainsi un important réservoir de biodiversité. .... des animaux menacés de l‟IUCN (Union. Internationale pour la Conservation de la. Nature) comporte plus de 100 ..... lacunes de notre compréhension des capacités de réponses et d‟adaptation de la biodiversité. Jackson et al.

  4. Sorption reactions in groundwater: various aspects to modelling the transport behaviour of zinc; Sorptionsreaktionen im Grundwasser: Unterschiedliche Aspekte bei der Modellierung des Transportverhaltens von Zink

    Energy Technology Data Exchange (ETDEWEB)

    Hadeler, A.

    1999-08-01

    The dispersal of trace substance in groundwater may be limited by dissolution and precipitation and, of particular interest in this paper, by sorption and desorption processes. These surface-active processes, which have a decisive influence on groundwater quality, depend on the concomitant geochemical conditions prevailing in the water, the constituents of the aquifer and on the surface properties of the solids. Taking the geochemical conditions prevailing naturally in brown coal mining areas as a point of departure this study was aimed at examining the influence of acidification processes on the transport behaviour inorganic pollutants for the example of zinc. For this purpose oxic column trials were carried out on sandy aquifer material. The data were supplemented by a detailed characterisation of the solid surfaces and modelled on the basis of a transport-reaction model as well as mechanistically with due regard to surface complexing. [German] Die Ausbreitung von Spurenstoffen im Grundwasser wird ausser durch Loesungs- und Faellungsprozesse vor allem durch Sorptions- bzw. Desorptionsvorgaenge limitiert. Diese fuer die Grundwasserqualitaet entscheidenden oberflaechenaktiven Prozesse sind von den variablen geochemischen Randbedingungen im Wasser, vom Stoffbestand des Aquifers und von den Oberflaecheneigenschaften der Feststoffe abhaengig. In Anlehnung an die natuerlichen im Bereich von Braunkohle-Abbaugebieten herrschenden geochemischen Bedingungen wurde der Einfluss von Versauerungsprozessen auf das Transportverhalten von anorganischen Schadstoffen, am Beispiel von Zink, auf der Basis von oxischen Saeulenversuchen an sandigem Aquifermaterial untersucht. Die Daten wurden durch eine detaillierte Charakterisierung der Feststoff-Oberflaechen ergaenzt und sowohl mit Hilfe eines Transport-Reaktionsmodells als auch mechanistisch unter Einbeziehung der Oberflaechenkomplexierung modelliert. (orig.)

  5. Self-consistent Random Phase Approximation applied to a schematic model of the field theory; Approximation des phases aleatoires self-consistante appliquee a un modele schematique de la theorie des champs

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, Thierry [Inst. de Physique Nucleaire, Lyon-1 Univ., 69 - Villeurbanne (France)

    1998-12-11

    The self-consistent Random Phase Approximation (SCRPA) is a method allowing in the mean-field theory inclusion of the correlations in the ground and excited states. It has the advantage of not violating the Pauli principle in contrast to RPA, that is based on the quasi-bosonic approximation; in addition, numerous applications in different domains of physics, show a possible variational character. However, the latter should be formally demonstrated. The first model studied with SCRPA is the anharmonic oscillator in the region where one of its symmetries is spontaneously broken. The ground state energy is reproduced by SCRPA more accurately than RPA, with no violation of the Ritz variational principle, what is not the case for the latter approximation. The success of SCRPA is the the same in case of ground state energy for a model mixing bosons and fermions. At the transition point the SCRPA is correcting RPA drastically, but far from this region the correction becomes negligible, both methods being of similar precision. In the deformed region in the case of RPA a spurious mode occurred due to the microscopical character of the model.. The SCRPA may also reproduce this mode very accurately and actually it coincides with an excitation in the exact spectrum 40 refs., 33 figs., 14 tabs.

  6. La revolution des savants

    CERN Document Server

    Chavanne, A

    1989-01-01

    Premiere cassette : - 1666 : impact de la creation de l'Academie des Sciences par Colbert, trente ans apres le proces de Galile, et au moment des disparitions de Pascal, Descartes et Fermat. Elle dirigee par le hollandais Huyggens jusqu'a sa fuite de France au moment de la revocation de l'Edit de Nantes. - 1750 : l'Encyclopedie (ou "Dictionnaire raisonne des Sciences, des Arts et des Metiers") de Diderot et d'Alembert, soutenus par Malherbes, Buffon, Condorcet et Rousseau. - 1789 : Revolution francaise. - 8 aout 1793 : l'Assemblee, par une declaration de Marat, dissout l'Academie des Sciences. Celle-ci continue cependant ses travaux pour les poids et mesures jusqu'en 1795. - la Terreur : la condamnation a mort, pas au nom d'une "Revolution qui n'a pas besoin de savants" mais pour d'autres raisons, de trois grands hommes de science : Lavoisier, Bailly et Condorcet. - 1793-1794 : Au printemps 93, le Comite de Salut Publique s'inquiete du demi-million de soldats etrangers de toutes les pays frontaliers qui essai...

  7. Modeling of transports of water and matter in landscape. Proceedings; Modellierung des Wasser- und Stofftransportes in grossen Einzugsgebieten. Beitraege

    Energy Technology Data Exchange (ETDEWEB)

    Bronstert, A.; Krysanova, V.; Schroeder, A.; Becker, A.; Bork, H.R. [eds.

    1998-04-01

    During recent years, the quantitative description of the water fluxes and the coupled transport of physical and chemical matter in the landscape has become steadily more and more important. The reasons for this are an increasing public awareness about the possible impacts of changes of land use, land cover, and of changes in regional and global climatic conditions together with a need for sound, multi-objective management of large river basins. The investigation areas of concern a usually much larger in extent than a typically sized hydrological investigation catchment. The tools primarily used in the quantification of the hydrological fluxes at the large scale are the so-called large-scale hydrological models. These models are comparatively new and still at the stage of development and improvement. The mentioned need for advanced large-scale hydrological models provided the reason for inviting scientists from German-speaking countries with experience in large-scale hydrological and hydro-meteorological models to exchange and discuss their modelling concepts and to identify research needs. The workshop was held at the Potsdam Institute for Climate Impact Research (PIK) on 15 and 16 December 1997, and was jointly organised by PIK, the University of Potsdam and the Centre for Agriculture and Land Use Research (ZALF). The workshop was attended by over 40 scientists, of whom 19 gave a presentation. (orig.)

  8. Modeling and numerical study of transfers in fissured environments; Modelisation et etude numerique des transferts en milieux fissures

    Energy Technology Data Exchange (ETDEWEB)

    Granet, S.

    2000-01-28

    Oil recovery from fractured reservoirs plays a very important role in the petroleum industry. Some of the world most productive oil fields are located in naturally fractured reservoirs. Modelling flow in such a fracture network is a very complex problem. This is conventionally done using a specific idealized model. This model is based on the Warren and Root representation and on a dual porosity, dual permeability approach. A simplified formulation of matrix-fracture fluid transfers uses a pseudo-steady-state transfer equation involving a constant exchange coefficient. Such a choice is one of the main difficulties of this approach. To get a better understanding of the simplifications involved in the dual porosity approach a reference model must be available. To obtain such a fine description, we have developed a new methodology. This technique called 'the fissure element methodology' is based on a specific gridding of the fractured medium. The fissure network is gridded with linear elements coupled with an unstructured triangular grid of matrix. An appropriate finite volume scheme has been developed to provide a good description of the flow. The numerical development of is precisely described. A simulator has been developed using this method. Several simulations have been realised. Comparisons have been done with different dual-porosity dual-permeability models. A reflexion concerning the choice of the exchange coefficient used in the dual porosity model is then proposed. This new tool has permit to have a better understanding of the production mechanisms of a complex fractured reservoir. (author)

  9. ``Statistical treatment of the spectral properties of plasmas in local thermodynamical equilibrium using a screened hydrogenic model``; ``Traitement statistique des proprietes spectrales des plasmas a l`equilibre thermodynamique local dans le cadre du modele hydrogenique ecrante``

    Energy Technology Data Exchange (ETDEWEB)

    Faussurier, G.

    1996-12-31

    A new screened hydrogenic model is presented. The screening constants depend both on the principal n and orbital l quantum numbers. They have been obtained from numerical fits over a large data base containing ionization potentials and one-electron excitation energies of ions. A rapid and original method to compute the bound-bound and bound-free oscillator strengths is proposed. The discrete spectrum and the series continuum are connected by continuity, and the sum rules are respected. The screened hydrogenic average atom is well-adapted to describe multicharged ion plasmas in local thermodynamic equilibrium (LTE). Using the key principle of statistical mechanics, it is shown first that this model is properly defined and thermodynamically coherent. Secondly, a new method of detailed ionization stage accounting of a LTE plasma is explained. It can be used to reconstruct the distribution of integer charge states in such a plasma from any average atom model. The l -splitting allows one-electron transitions between two subshells with the same principal quantum number n. They may be of great importance when the Rosseland opacity is computed. Though, methods of classical statistical mechanics are required to calculate the distribution of the configurations around the average atom one and so to improve the spectral opacities. The splitting in integer ionic stages can be easily included. The formalism is tested by comparisons with theoretical and experimental results published in the literature. From the photoabsorption spectra encountered, the main results are the correct estimations of both the Rosseland opacity and the detailed charge degrees accounting. (author).

  10. Kinetic Modeling using the Single-Event Methodology: Application to the Isomerization of Light Paraffins Modélisation cinétique basée sur la méthodologie des événements constitutifs : application à l’isomérisation des paraffines légères

    Directory of Open Access Journals (Sweden)

    Surla K.

    2011-08-01

    described by a limited number of independent kinetic parameters. The behavior of complex feedstocks can therefore be predicted based on studies conducted on model molecules. This method is applied at IFP Energies nouvelles to several refining processes. The purpose of this article is to describe this methodology in a detailed manner and to present its application to the isomerization of C5-C6 paraffins. L’établissement de modèles cinétiques est une étape importante du développement de procédés de raffinage. En effet, ces modèles peuvent être utilisés pour prédire les performances du procédé, pour optimiser l’opération de l’unité et pour concevoir de façon optimale le réacteur et le procédé associé (choix du réacteur, détermination des conditions de marche optimale, utilisation de recyclages, etc.. La demande actuelle de modèles se focalise particulièrement sur la mise au point de modèles détaillés et prédictifs, qui sont capables de prendre en compte des variations importantes dans la conduite du procédé. De ce fait, ils doivent être extrapolables à des conditions opératoires très différentes ou à des charges très diverses. La modélisation cinétique par événements constitutifs satisfait ces critères car elle permet d’obtenir une prédiction détaillée des effluents des réacteurs. La théorie des événements constitutifs a été initialement développée pour la chimie radicalaire [Clymans et Froment (1984 Comput. Chem. Eng. 8, 2, 137-142; Hillewaert et al. (1988 AIChE J. 34, 1, 17-24; Willems et Froment (1988a Ind. Eng. Chem. Res. 27, 11, 1959-1966; Willems et Froment (1988b Ind. Eng. Chem. Res. 27, 11, 1966-1971] et a été étendue ultérieurement à la catalyse acide [Baltanas et Froment (1985 Comput. Chem. Eng. 9, 1, 71-81; Baltanas et al. (1989 Ind. Eng. Chem. Res. 28, 899-910; Vynckier et Froment (1991 Modeling of the kinetics of complex processes upon elementary steps, in Kinetic and thermodynamic lumping of

  11. Modelling of heterogenous neutron leakages in a nuclear reactor; Modelisation des fuites heterogenes de neutrons dans un reacteur nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Wohleber, X

    1997-11-17

    The TIBERE Model is a neutron leakage method based on B{sub 1} heterogeneous transport equation resolution. In this work, we have studied the influence of the reflection mode at the boundary of the assembly. In particular the White boundary condition has been implemented in the APOLLO2 neutron transport code. We have compared the two TIBERE kinds of boundary conditions (specular and white) with the classical B{sub 1} homogeneous leakage method in the modelling of some reactors. We have remarked the better capability of the TIBERE Model to compute voided assemblies. The white boundary condition is also able to compute a completely voided assembly and, besides, wins a factor 10 in CPU time in comparison with the specular boundary condition. These two heterogenous leakage formalisms have been tested on a partially voided experiment and have shown that the TIBERE Model can compute this kind of situation with a greater precision than the classical B{sub 1} homogeneous leakage method, and with a shorter computational time. (author)

  12. Compositional thermodynamic model of asphaltenes flocculation out of crudes; Modelisation thermodynamique compositionnelle de la floculation des bruts asphalteniques

    Energy Technology Data Exchange (ETDEWEB)

    Szewczyk, V.

    1997-12-02

    The aim of this work is to propose to the oil industry a compositional thermodynamic model able to predict the operating conditions which induce asphaltenes flocculation out of crudes. In this study, various analytical methods (calorimetry, elemental analysis, {sup 13}C nuclear magnetic resonance, neutron diffusion,...) have been used in order to get a better description of the asphaltene fraction to infer its flocculation mechanism. The proposed model describes this flocculation as a thermodynamic transition inducing the formation of a new liquid phase with a high asphaltene content and formed by all the components initially in the crude: the asphaltene deposit. Asphaltenes are represented as a pseudo-component essentially made of carbon and hydrogen. The analytical modelling of the F11-F20 light fraction is the one proposed by Jaubert (1993). The F20+ heavy fraction is represented by four pseudo-components, their physical properties are calculated using the group contribution methods of Avaullee (1995) and of Rogalski and Neau (1990). The Peng-Robinson equation of state (1976) combined with the Abdoul and Peneloux group contribution mixing rules (1989) is used in order to restitute the gas-liquid-asphaltene deposit phase equilibria. This model not being able to compute flocculation conditions on a predictive manner, the method consists in fitting some physical properties of the pseudo-components introduced in the analytical representation of the asphaltene crudes. he obtained results show results show that the proposed flocculation model is then well adapted to the description of the thermodynamic properties (saturation pressures, relative volumes, flocculation curves) of asphaltene crudes within a relatively large range of temperature (30-150 deg C) and pressure (0.1-50 MPa), covering the majority of conditions met in oil production. (author) 109 refs.

  13. Cross section and di-fermionic asymmetry measurements by ALEPH detector at LEP2 - Interpretations beyond Standard Model; Mesures des sections efficaces et des asymetries difermioniques avec le detecteur Aleph a LEP2 - Interpretations au-dela du Modele Standard

    Energy Technology Data Exchange (ETDEWEB)

    Merle, Elsa [Laboratoire d' Annecy-le-vieux de physique des particules, Grenoble-1 Univ., 74 Annecy (France)

    1999-04-22

    The present work is based on the selection of e{sup -}e{sup +} {yields} f f-bar events taken with the ALEPH detector from 1995 to 1998, for an integrated luminosity of 500 pb{sup -}. We first present the selection of dimuon, di-tau and di-electron events that we have been developed for this study. The hadronic selection used in ALEPH is also detailed in a devoted part. In each case, the estimation of systematic uncertainties is described. They are of the same order of magnitude as the statistical errors, ranging between 0.6% (di-electron) and 3.5% (dimuon). From these selections we derive the di-fermionic cross-sections as well as the asymmetries computed for the di-lepton channels. Measurements are found to be in reasonable agreement with the Standard Model expectations. Cross-sections and asymmetries are sensitive to the presence of possible new physics. In this document we use the context of the 4-fermion contact interactions to set limits on the energy scale of new physics. Such limits are found to range between 7 and 15 GeV depending on the modelling used. We also put lower limits on the mass of leptoquarks, 590 GeV/c{sup 2} for vector leptoquarks and 71 GeV/c{sup 2} for scalar leptoquarks. Eventually we also present the limits derived in the context of R-parity violated supersymmetry, putting constraint on the s-neutrino mass. Our study excludes such particles below a few hundred GeV/c{sup 2} mass for high values of their Yukawa coupling assumptions.

  14. Model project to promote cultivation and utilization of renewable resources. Modellvorhaben zur Foerderung des Anbaus und der Verwertung nachwachsender Rohstoffe

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    This revised report on the model projects presents individual projects and measures complementary to each other, documenting, in their totality, an advanced state of development. Moreover it shows the following: that the basic challenge of a model project, especially in the field of the energetic use of biomass, can be met by marrying agriculture to power utilities. So, projects are under way where cultivation of China reed and its utilization in power-and-heat cogeneration plants will, in the future, complement each other. Further questions that are not represented in the research programme of Lower Saxonia are dealt with at the federal level, so that the field of renewable resurces may currently be considered as comprehensively covered. (orig./EF).

  15. Compression-absorption (resorption) refrigerating machinery. Modeling of reactors; Machine frigorifique a compression-absorption (resorption). Modelisation des reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Lottin, O.; Feidt, M.; Benelmir, R. [LEMTA-UHP Nancy-1, 54 - Vandoeuvre-les-Nancy (France)

    1997-12-31

    This paper is a series of transparencies presenting a comparative study of the thermal performances of different types of refrigerating machineries: di-thermal with vapor compression, tri-thermal with moto-compressor, with ejector, with free piston, adsorption-type, resorption-type, absorption-type, compression-absorption-type. A prototype of ammonia-water compression-absorption heat pump is presented and modeled. (J.S.)

  16. Advanced model for poly dispersion in size in boiling flows; Modelisation avancee de la polydispersion en taille des ecoulements bouillants

    Energy Technology Data Exchange (ETDEWEB)

    Ruyer, P.; Seiler, N. [Institut de Radioprotection et Surete Nucleaire Cadarache, 13 - Saint Paul lez Durance (France)

    2009-07-01

    This work has been performed within the Institut de Radioprotection et de Surete Nucleaire that leads research programs concerning safety analysis of nuclear power plants. During a LOCA (Loss Of Coolant Accident), in-vessel pressure decreases and temperature increases, leading to the onset of nucleate boiling. The present study focuses on the numerical simulation of the local topology of the boiling flow. There is experimental evidence of a local and statistical large spectrum of possible bubble sizes. The relative importance of the correct description of this poly-dispersion in size is due to the dependency of (i) main hydrodynamic forces, as well as of (ii) transfer area with respect to the individual bubble size. We study the corresponding CFD model in the framework of an ensemble averaged description of the dispersed two-phase flow. The transport equations of the main statistical moment densities of the population size distribution are derived and models for the mass, momentum and heat transfers at the bubble scale as well as for bubble coalescence are achieved. This model introduced within NEPTUNE-CFD code of the NEPTUNE thermal-hydraulic platform, a joint project of CEA, EDF, IRSN and AREVA-NP, has been tested on boiling flows obtained on the DEBORA facility of the CEA at Grenoble. These numerical simulations provide a validation, check the meshing convergence as well as the impact of the various phenomena onto the local flow topology prediction. (authors)

  17. Quantifizierung des Einflusses der äußeren Produktgestaltung auf die Geschmacksbewertung und auf die Kaufbereitschaft bei Wein mittels eines Charakteristika-Modells

    OpenAIRE

    Szolnoki, Gergely; Hoffmann, Dieter; Herrmann, Roland

    2008-01-01

    Die erhebliche Erweiterung des Weinangebots in den letzten Jahren hat zu einer großen Differenzierung geführt, die nicht nur über eine stärkere Variation der Geschmackseindrücke erkennbar ist, sondern auch durch die zunehmende Verwendung von Qualitätssignalen. Als Qualitätssignale werden verschiedene extrinsische Informationen verwendet, wie Herkunft, Rebsorte oder Markennamen, aber auch das Produktdesign. In diesem Beitrag wird analysiert, inwieweit diese äußere Produktgestaltung des Weines ...

  18. Etude des comportements rheologiques des melanges de farine ble ...

    African Journals Online (AJOL)

    Etude des comportements rheologiques des melanges de farine ble/sorgho sans tanins issue de trois nouvelles varietes cultivees au Senegal et mise au point de pains a base de farines composees (ble/sorgho)

  19. Effets des biomasses vertes de Tithonia diversifolia et des engrais ...

    African Journals Online (AJOL)

    Effets des biomasses vertes de Tithonia diversifolia et des engrais minéraux sur la croissance, le développement et le rendement du manioc ( Manihot esculenta Crantz) en zone forestière du Cameroun.

  20. À propos des occasionnalismes

    Directory of Open Access Journals (Sweden)

    Dal Georgette

    2016-01-01

    Full Text Available Les occasionnalismes (nonce formations ou contextual formations dans la terminologie anglo-saxonne, qu’on définira provisoirement comme de “new complex word[s] created by a speaker/writer on the spur of the moment to cover some immediate need” (Bauer, 1983 : 45 ont, à notre connaissance, peu retenu l’attention des morphologues du domaine francophone. Pourtant, toutes les conditions sont désormais réunies pour que cet objet, invisible lorsqu’il s’agissait de décrire le système morphologique du français (ou d’autres langues à partir de ressources dictionnairiques, émerge en tant qu’observable dans une morphologie puisant ses données dans le réel langagier des locuteurs. Par définition en effet, on s’attend à ce qu’un occasionalisme soit absent des dictionnaires (nous verrons que, dans les faits, la situation est plus complexe que cela, et que ces contextual formations ne puissent pas être étudiées en dehors du contexte dans lequel elles ont été produites. À cet égard, la Toile et les produits qui en dérivent constituent des ressources de choix. C’est particulièrement vrai des forums, dans lesquels les internautes s’expriment librement, laissant libre cours à leur potentiel créatif (ou ce qu’ils pensent tel. Dans la présente communication, après avoir défini la notion d’occasionalisme, nous utiliserons un corpus constitué au fil d’autres recherches pour dégager des motifs récurrents propices à leur apparition, autrement dit pour établir une grammaire des occasionnalismes.

  1. La mobilite internationale des facteurs de production en situation de chomage et de libre-echange commercial: une revue de la problematique.

    OpenAIRE

    Tremblay, R.

    1996-01-01

    Cet article fait un recensement des analyses theoriques et empiriques concernant les effets possibles de la mobilite internationale des facteurs de production. les resultats et les recommendations du modele de base sont etablis quand prevalent le plein-emploi et l'ajustement complet des marches. les resultats des diverses analyses, dans un contexte de chomage structurel, sont ensuite identifies.

  2. Reseau des polygones de bord des indicateurs de performance d ...

    African Journals Online (AJOL)

    La fonction maintenance hospitalière a des composantes spécifiques qui la rendent de plus en plus complexe et fastidieuse. La politique d'une maintenance biomédicale repose sur des piliers et des leviers propres à une meilleure exploitation des dispositifs médicaux dans un système de santé. Trois niveaux de leviers ...

  3. Impact des microcredits sur les conditions sociosanitaires des ...

    African Journals Online (AJOL)

    Cependant, très peu d'étude se focalisent sur leurs impacts réels sur les conditions de vies des bénéficiaires de leurs services. C'est à ce propos que la présente recherche se donne comme objectif de contribuer à une meilleure connaissance des impacts des microcrédits - un des services offert par les IMF - sur les ...

  4. Promouvoir l'entrepreneuriat inclusif des jeunes et des femmes ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le projet vise à analyser la contribution réelle et potentielle de l'entrepreneuriat inclusif au bien-être des jeunes et des femmes en Côte d'Ivoire, au Burkina Faso et au Kenya. Après un état des lieux de la pratique de l'entrepreneuriat inclusif dans chacun des pays ciblés, l'équipe de recherche étudiera son incidence sur ...

  5. Modèle de foration fondé sur le couplage des effets de destruction de la roche et d'évacuation des déblais (bilan solide A Drilling Model Based on Coupling Between Rock Crushing Effects and Bottom Hole Hydraulic Cleaning of Cuttings (Solid Balance

    Directory of Open Access Journals (Sweden)

    Putot C.

    2006-11-01

    Full Text Available Une première partie rappelle les progrès accomplis dans la représentation du phénomène de forabilité et l'insuffisance des modèles actuels négligeant la dimension hydraulique. L'analyse des diagraphies de poids, couple et vitesse de pénétration doit être revue et l'éclairage apporté par la représentation proposée semble de nature à résoudre certaines difficultés d'interprétation. L'ambiguïté soulevée par la présence simultanée de deux mécanismes possibles de colmatage, l'un naissant au contact de l'outil, l'autre au fond du trou, est évoquée. La deuxième partie concerne la description proprement dite du modèle. Il s'agit d'un schéma préliminaire, assorti d'hypothèses physiques dont certaines pourront paraître grossières. Son intérêt est de montrer qu'avec des considérations rudimentaires mais intuitivement satisfaisantes, l'essentiel du phénomène est décrit et notamment l'allure du processus de bourrage tel que le présente D. Close (1993 Ce schéma aux hypothèses assez restrictives appelle donc des améliorations de tout ordre qui seront abondamment commentées. The first part reviews the progress made in representing the phenomenon of drillability and the insufficiency of current models that neglect the hydraulic dimension. The analysis of weight on bit logs, torque and rate of penetration must be revised, and the insight provided by the proposed representation seems to be of help in solving various interpretation difficulties. The ambiguity created by the simultaneous presence of two possible plugging mechanisms - one stemming from the contact of the bit and the other from the bottom of the borehole - is dealt with. The second part describes the model itself. It is a preliminary sketch combined with physical hypotheses, some of which may seem approximate. Its importance lies in showing that, with rudimentary but intuitively satisfactory considerations, the essential of the phenomenon is described, and

  6. Etude theorique et experimentale des evaporateurs de dioxyde de carbone operant dans des conditions de givrage

    Science.gov (United States)

    Bendaoud, Adlane Larbi

    . Dans la partie theorique, un modele traitant les aspects thermique, hydrodynamique et massique a ete elabore. Sur la base de ce modele a ete ecrit un programme informatique en langage FORTRAN 6.6. Il est base sur la discretisation du serpentin en volumes de controle, est entierement automatise et peut traiter des echangeurs de chaleur avec des circuits de refrigerant complexes pouvant avoir des entrees et sorties multiples ainsi que des bifurcations. La presence simultanee des trois phases thermodynamiques du refrigerant (liquide sous refroidi, fluide sature, vapeur surchauffee) dans le serpentin est aussi prise en charge. Le modele a ete valide pour un fonctionnement avec et sans formation de givre en utilisant des donnees experimentales disponibles dans la litterature et celles obtenues sur le banc d'essai de CanmetENERGIE. Celui-ci a ete mis a jour pour les besoins de la presente recherche et pour cela, un systeme de surchauffe et d'injection de la vapeur d'eau dans une enceinte a tres basse temperature a ete dimensionne, fabrique et installe. Un dispositif de visualisation de la formation de givre, ainsi qu'un equipement de mesure de la temperature, de la pression et de l'humidite relative de l'air ont aussi ete ajoutes. Une fois le modele valide, des simulations numeriques sur le serpentin avec et sans formation de givre ont ete effectuees. Un premier cas de base a servi comme reference pour d'autres cas pour lesquels une etude parametrique sur la geometrie et le fonctionnement a ete menee. Il a ete montre par rapport au cas de base que : 1. la diminution de la densite des ailettes sur des rangees specifiques du serpentin donne une surface minimale (Amin) plus grande, retardant ainsi l'obstruction totale du serpentin par le givre et permet donc un temps de fonctionnement plus grand et une frequence de degivrage plus faible. 2. une bonne configuration de circuit de refrigerant augmente le temps de fonctionnement du serpentin de 200 % et delivre une puissance

  7. L'amelioration potentielle des sciages d'epinette noire en tenant compte des noeuds

    Science.gov (United States)

    Lemieux, Hugo

    Cette recherche a pour but de determiner l'amelioration potentielle de la resistance mecanique des sciages d'epinette noire. Un echantillon de billes a ete mesure afin de caracteriser les noeuds en surface. Un sous-echantillon a ete disseque afin de caracteriser les noeuds. Ces mesures ont servi dans un modele de debitage de billes et de classement des planches qui prend en compte les noeuds. Des simulations de sciage et de classement ont ete effectuees sur toutes les billes en faisant des rotations de celles-ci. Les simulations ont determine les positions qui donnent un meilleur et un pire rendement au niveau du classement. La moitie des billes a ensuite ete sciee par rapport a une meilleure position et l'autre moitie par rapport a la pire solution. Les sciages ont ete classes visuellement par rapport aux noeuds seulement et par rapport a tous les defauts. Ils ont ensuite ete testees a destruction. L'analyse a determine que les noeuds n'ont pas d'effet sur le classement visuel des sciages mais qu'ils ont eu un effet marque sur la resistance mecanique.

  8. La fabrique des sciences des institutions aux pratiques

    CERN Document Server

    Benninghoff, Martin; Crettaz von Roten, Fabienne; Merz, Martina

    2006-01-01

    Aujourd'hui, les façons de produire, d'organiser, d'évaluer et d'utiliser les savoirs sont en profond débat. De plus en plus, l'Etat, la société civile et l'économie tentent d'influencer les activités des universités et des laboratoires de recherche. Ces développements mettent à l'épreuve tout à la fois les fondements des systèmes d'enseignement supérieur et de recherche, l'autonomie des institutions scientifiques, la définition des frontières des savoirs et l'acceptation des sciences. Dans des contextes suisses et européens, cet ouvrage s'intéresse aux manières dont les sciences et les technologies sont fabriquées, en analysant leurs institutions et les pratiques. A partir d'une approche relationnelle, les sciences et les technologies sont conçues comme des phénomènes profondément sociaux, culturels et politiques. Une telle démarche déstabilise les visions parfois idéalisées et stéréotypées de la construction des savoirs. Des études de cas détaillées décrivent des phénomè...

  9. Effets des extraits vegetaux sur la dynamique de populations des ...

    African Journals Online (AJOL)

    La présente étude se propose de trouver une alternative de l'utilisation des pesticides chimiques en testant l'effet insecticide des extraits aqueux des feuilles de Hyptis suaveolens, graines de Ricinus communis et de Azadirachta indica contre les ravageurs du niébé en conditions de champ en utilisant le cyperméthrine ...

  10. Costs of treatment of haemophilia A in Italy: comparison of the use of plasma-derived and recombinant FVIII using a discrete event simulation (DES model

    Directory of Open Access Journals (Sweden)

    Mario Eandi

    2013-06-01

    Full Text Available OBJECTIVE: To simulate haemophilia A (HA real-life management and compare the cost of different treatment strategies, both with plasma-derived and recombinant factor VIII (pdFVIII and rFVIII, respectively, from the perspective of the Italian NHS.METHODS: A discrete event (micro-simulation (DES model was developed to reproduce every possible HA patient clinical pathway: on-demand (OD treatment of bleeding, continuous or discontinuous prophylaxis (PRO with FVIII, inhibitors-tolerance-induction treatment (ITI, surgery in case of severe disability. Patient characteristics, treatment indications and disease evolution were modeled basing on data available in clinical literature in order to represent the actual state of art of HA management. In addition to the baseline scenario, reproducing current HA management, alternative strategies were simulated to explore the impact on the cost borne by the Italian NHS for these patients. Only differential direct sanitary costs were considered in the simulation, with a 3.5% discount rate.RESULTS: Baseline scenario results show difference between patients treated with pdFVIII and those treated with rFVIII: mean lifetime HA patient management cost was estimated at € 1,332,373 with pdFVIII treatment, compared with € 2,013,222 for rFVIII. The saving is due mainly to the lower acquisition cost of pdFVIII. Total medical costs are strongly and positively correlated with HA severity: cost per patient increases from € 86,269 (mild HA to € 1,509,231 (severe HA for patients treated with pdFVIII and from € 147,900 to € 2,621,540 in patients treated with rFVIII. All analyses conducted in the study lead to the conclusion that the use of pdFVIII is much less expensive than rFVIII, but therapeutically equivalent.CONCLUSION: Management of HA patients is complex and difficult to optimize; although involving a limited number of patients, lifetime management costs for the Italian NHS are extremely high. The main

  11. Indoor radon; Le radon dans les batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The radon, a natural radioactive gas, is present almost everywhere on the earth's surface. It can be accumulated at high concentration in confined spaces (buildings, mines, etc). In the last decades many studies conducted in several countries showed that inhaling important amounts of radon rises the risk of lung cancer. Although, the radon is a naturally appearing radioactive source, it may be the subject of a human 'enhancement' of concentration. The increasing radon concentration in professional housing constitutes an example of enhanced natural radioactivity which can induce health risks on workers and public. Besides, the radon is present in the dwelling houses (the domestic radon). On 13 May 1996, the European Union Council issued the new EURATOM Instruction that establishes the basic standards of health protection of population and workers against the ionizing radiation hazards (Instruction 96/29/EURATOM, JOCE L-159 of 29 June 1996). This instruction does not apply to domestic radon but it is taken into consideration by another EURATOM document: the recommendation of the Commission 90/143/EURATOM of 21 February 1990 (JOCE L-80 of 27 March 1990). The present paper aims at establishing in accordance to European Union provisions the guidelines for radon risk management in working places, as well as in dwelling houses, where the implied risk is taken into account. This document does not deal with cases of high radon concentration on sites where fabrication, handling or storage of radium sources take place. These situations must be treated by special studies.

  12. Building integrated photovoltaic; Photovaltaique integre aux batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-01-01

    Durable, modular and flexible in use, as demonstrated by the different case studies in this publication, photovoltaic can replace diverse building elements, from glass facades to weather proof roofs. This leaflet towards architects describes aesthetic, technical, economic and environmental interest of building integrated photovoltaic. (author)

  13. Tables of formulae for calculating the mechanics of stacks in gas-graphite reactors; Formulaire pour le calcul de la mecanique des empilements des reacteurs graphite-gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1968-07-01

    This collection of formulae only gives, for nuclear graphite stacks. The mechanical effects due to the strains, thermal or not, of steel structures supporting or surrounding graphite blocks. Equations have been established by mean of experiments made at Chinon with large pile models. Thus, it is possible to calculate displacement, strain and stress in the EDF type stacks of horizontal triangular block lattice. (authors) [French] Le domaine de ce formulaire est strictement limite aux effets mecaniques, pour les empilements, des deformations, thermiques ou autres, des structures metalliques de soutien (aire - support et corset). On propose un ensemble de relations qui ont ete etablies a la suite des essais de CHINON sur des maquettes de grande taille. Ces relations permettent le calcul des mouvements, des deformations et des contraintes dans les empilements du type EDF, a reseau horizontal triangulaire regulier. (auteurs)

  14. Concevoir des modèles de sites Web éducatifs en utilisant IMS Learning Design / Designing educational Web site models using IMS Learning Design

    Directory of Open Access Journals (Sweden)

    Ecaterina Giacomini Pacurar

    2006-02-01

    Full Text Available Dans le cadre de cette recherche, a été développé le guide interactif CEPIAH (Conception et Evaluation des Produits Interactifs pour l’Apprentissage Humain accessible sur le Web, composé de trois modules : Aide à la Conception, Aide à l’Evaluation et Aide à la Conception de structures de cours en ligne. L’objectif de cet environnement interactif est d’aider les auteurs de sites Web éducatif dans la conception et l’évaluation de leurs prototypes. Cet article présente une courte synthèse et analyse des normes relatives à la conception des contenus pédagogiques électroniques; ensuite seront décrits les travaux de recherche concernant le troisième module (Aide à la Conception de structures de cours en ligne du guide CEPIAH. La conclusion présentera des perspectives portant sur la validation de l’outil.

  15. Thermodynamical modeling of nuclear glasses: coexistence of amorphous phases; Modelisation thermodynamique des verres nucleaires: coexistence entre phases amorphes

    Energy Technology Data Exchange (ETDEWEB)

    Adjanor, G

    2007-11-15

    Investigating the stability of borosilicate glasses used in the nuclear industry with respect to phase separation requires to estimate the Gibbs free energies of the various phases appearing in the material. In simulation, using current computational resources, a direct state-sampling of a glassy system with respect to its ensemble statistics is not ergodic and the estimated ensemble averages are not reliable. Our approach consists in generating, at a given cooling rate, a series of quenches, or paths connecting states of the liquid to states of the glass, and then in taking into account the probability to generate the paths leading to the different glassy states in ensembles averages. In this way, we introduce a path ensemble formalism and calculate a Landau free energy associated to a glassy meta-basin. This method was validated by accurately mapping the free energy landscape of a 38-atom glassy cluster. We then applied this approach to the calculation of the Gibbs free energies of binary amorphous Lennard-Jones alloys, and checked the correlation between the observed tendencies to order or to phase separate and the computed Gibbs free energies. We finally computed the driving force to phase separation in a simplified three-oxide nuclear glass modeled by a Born-Mayer-Huggins potential that includes a three-body term, and we compared the estimated quantities to the available experimental data. (author)

  16. Performance Analysis of Compositional and Modified Black-Oil Models For a Gas Lift Process Analyse des performances de modèles black-oil pour le procédé d’extraction par injection de gaz

    Directory of Open Access Journals (Sweden)

    Mahmudi M.

    2013-03-01

    Full Text Available Artificial gas lift is frequently used to boost production rate of mature oil fields. An integrated mathematical model was developed in order to track the spatial and temporal changes in various components of the continuous gas lift process. The computational demand for solving the comprehensive gas lift model highly depends on the thermodynamic treatment of the hydrocarbon fluids involved. A full compositional treatment using an equation of state provides the most accurate results but at a high computational cost. The results of this article showed that the computational cost can be halved without sacrificing accuracy by using reduced parameter stability and flash calculation procedures. It was also demonstrated that a Modified Black-Oil treatment of the fluids can provide reasonable accuracy at a much-reduced computational cost. The Modified Black-Oil treatment provides a valuable tool when the model has to be solved many hundreds of times to find the optimal combination of the gas lift parameters. Les procédés artificiels d’extraction par injection de gaz sont utilisés pour améliorer le taux de récupération des champs pétroliers matures. Un modèle mathématique intégré a été développé pour détecter de faibles changements temporels et spatiaux dans plusieurs composants des procédés continus d’extraction par injection de gaz. La solution numérique utilisée pour résoudre le modèle du procédé d’extraction dépend fortement du comportement thermodynamique des hydrocarbures impliqués. Un traitement complet de la composition utilisant une équation d’état offre les résultats les plus précis, mais à un coût de calcul très élevé. Les résultats de nos travaux de recherche montrent que l’implication des paramètres de stabilité et des procédures de calcul flash, peut diviser par deux le coût du calcul tout en gardant la précision attendue. Ces travaux montrent que la précision admissible peut être

  17. Modelling Adsorption of Foam-Forming Surfactants on Heterogeneous Surfaces Using the Surface Excess Formalism Conception de modèle pour l'adsorption des agents tensio-actifs moussants sur des surfaces hétérogènes en faisant appel au formalisme de l'excès de surface

    Directory of Open Access Journals (Sweden)

    Mannhardt K.

    2006-11-01

    Full Text Available Adsorption at the solid/liquid interface is detrimental to most enhanced oil recovery processes that make use of surfactants. This paper describes several extensions to a previously described surface excess model of adsorption in flow through porous media [7, 8]. It is shown that two parameters of the model, the monolayer coverages of surfactant and water, can be determined independently, thus reducing the number of adjustable parameters in the model from six to four. Experimental evidence suggests that the selectivity, previously assumed constant, should be a function of concentration. A functional form of selectivity that is derived from thermodynamic principles is incorporated into the model. Finally, adsorption on heterogeneous surfaces is discussed, and a simple form of surface heterogeneity (a bimodal distribution of selectivities is incorporated into the model and its benefits in determining adsorption isotherms from core flood data are demonstrated. L'adsorption à l'interface solide/liquide nuit aux procédés de RAH qui utilisent des tensio-actifs. Pour la réussite de ces procédés, il est par conséquent impératif de connaître les niveaux d'adsorption et de bien en comprendre les mécanismes. Le modèle qui fait appel au concept d'excès de surface pour décrire l'adsorption dans les écoulements traversant un milieu poreux a été décrit dans des articles précédents et a été utilisé pour évaluer l'adsorption d'un certain nombre d'agents tensioactifs moussants [7,8]. Le présent article étudie trois développements de ce modèle. Le modèle d'adsorption comporte un ensemble de paramètres ajustables qui sont utilisés pour faire correspondre les concentrations d'effluents simulées et expérimentales lors d'une injection en milieu poreux. Ces paramètres peuvent ensuite être utilisés pour calculer les isothermes d'adsorption de certains systèmes. Deux des paramètres du modèle, les revêtements monocouche de

  18. Les lueurs des sables

    CERN Multimedia

    Les lueurs des sables

    2013-01-01

    Two CERN ladies are getting ready for the “Trophée Roses des Sables” rally adventure: Julie and Laetitia are finalizing the last details before setting off on Monday 7th October 2013. Julie from EN-MEF group and Laetitia from DGS-SEE group, met at the CERN Rugby club. This year, they are participating in the 100 % female rally which will take place in Morocco from 10 to 20 October. They will be carrying along 100 kg of humanitarian donation for children such as some clothes, books and medical material. Do not hesitate to show your support at their farewell party to be held on Monday 7 October, from 4 to 6 pm in front of the St Genis-Pouilly Mairie (city Hall). Follow their exciting adventure on the blog leslueursdessables.trophee-roses-des-sables.org and on their association’s Facebook page Les Lueurs des Sables.

  19. Pore-Scale Flow Simulations: Model Predictions Compared with Experiments on Bi-Dispersed Granular Assemblies Simulation d’écoulements à l’échelle porale : comparaison des prédictions du modèle et d’expériences sur mélanges de billes de verre bi-disperses

    Directory of Open Access Journals (Sweden)

    Tong A.-T.

    2012-11-01

    Full Text Available A method is presented for the simulation of pore flow in granular materials. The numerical model uses a combination of the discrete element method for the solid phase and a novel finite volume formulation for the fluid phase. The solid is modeled as an assembly of spherical particles, where contact interactions are governed by elasto-plastic relations. Incompressible Stokes flow is considered, assuming that inertial forces are small in comparison with viscous forces. Pore geometry and pore connections are defined locally through regular triangulation of spheres, from which a tetrahedral mesh arises. The definition of pore-scale hydraulic conductivities is a key aspect of this model. In this sense, the model is similar to a pore-network model. Permeability measurements on bi-dispersed glass beads are reported and compared with model predictions, validating the definition of local conductivities. Une méthode est présentée pour la simulation de l’écoulement porale dans les matériaux granulaires. Le modèle numérique est basé sur la méthode des éléments discrets pour la phase solide et sur une nouvelle méthode de type volumes finis pour la phase fluide. Le solide est modélisé comme un arrangement de particules sphériques avec des interactions de type élasto-plastique aux contacts. On considère un écoulement de Stokes incompressible en supposant que les forces inertielles sont négligeables par rapport aux forces visqueuses. La géométrie des pores et leur connectivité sont définies sur la base d’une triangulation régulière des sphères qui aboutit à un maillage tétraédrique. La définition des conductivités hydrauliques à l’échelle des pores est un point clef du modèle qui se rapproche sur ce point à des modèles de type pore-network. Des mesures de perméabilités sur des assemblages bi-disperses de billes de verre sont présentées et comparées aux prédictions du modèle ce qui valide la définition des

  20. Screening phytochimique et identification spectroscopique des ...

    African Journals Online (AJOL)

    Le screening phytochimique des feuilles et des fleurs de cette plante, effectuée pour la première fois, a révélé la présence des alcaloïdes, des flavonoïdes, des tanins catéchiques, des terpènes, des coumarines et des composés cyanogénétiques. Quant aux saponines et les quinones libres, ils sont présents chez les fleurs ...

  1. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Résumé. Dans ce travail, on s‟intéresse à l‟effet des concentrations du xanthane, du caséinate de sodium et du tween 20 sur les propriétés rhéologiques, ... macromolécules des deux biopolymères, par effet du volume exclu, auquel cas, les ..... 25 (4), 743-749. [8] Gast A.P., Hall C.K., Russel W.B.,. 1983. Polymer-induced ...

  2. Liste des tableaux

    OpenAIRE

    2014-01-01

    1 – Importations en charbon américain en Europe de l’Ouest de 1946 à 1958 .47 2 – Organisation des demandes d’allocations de charbon allemand auprès de l’eco. 75 3 – Consommations de charbon allemand dans les zones occidentales de l’Allemagne d’octobre à décembre 1945. 86 4 – Production, exportations et consommation nationale apparente du charbon allemand dans la zone britannique en 1945 et 1946. 90 5 – Total des importations de charbons allemand et américain de janvier à avril 1946. 99 6 – I...

  3. Table des tableaux

    OpenAIRE

    2018-01-01

    Tableau 1 : Production nationale d'alcool avant 1919 68 Tableau 2 : Production nationale d'alcool après 1939 (Source : Martraire, 1955, A.D. 77 : Az 7086) 71 Tableau 3 : Les surfaces agricoles disponibles en France en 2004 123 Tableau 4 : Le régime fiscal des carburants et des biocarburants en 2005 et 2006 (source : ADEME) 175 Tableau 5 : Exemple de coût de production de biocarburants (Source : Stéphane His (IFP), Les biocarburants en Europe, 2004) 176 Tableau 6 : L’application de la directiv...

  4. Penerapan Visual Basic for Application (VBA Sebagai Alat Bantu Ajar Enkripsi dan Dekripsi DES

    Directory of Open Access Journals (Sweden)

    Yasri Yasri

    2011-06-01

    Full Text Available The DES encryption/decryption algorithm is quite a popular algorithm due to ease in learning. Calculations for DES using binary numbers however are very difficult, including 16 rounds required for a full encode. Teaching DES encryption manually is difficult since it requires a long time. It also requires high accuracy for the 64-bit binary numbers, the possibility of mistakes are very high. Besides, the students cannot perform self-check, whether the given task is done correctly. Application of Excel and VBA is used to facilitate observation, comparison, and understanding the DES algorithm. The result is a teaching model using DES for modern encryption. 

  5. Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

    African Journals Online (AJOL)

    Face à ce constat, le défi de la recherche serait la détermination du niveau actuel de contamination des légumes feuilles et des eaux du barrage et celui de l'État serait l'initiation de programmes de sensibilisation des producteurs par rapport à une gestion plus rigoureuse des pesticides. Mots-clés : pratiques paysannes, ...

  6. Modeling of radiant heat transfers in non-grey gases using the discrete ordinate method in association with a narrow bands statistical model; Modelisation des transferts radiatifs dans des gaz non gris par la methode des ordonnees discretes associee a un modele statistique a bandes etroites

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, A.B. de; Delmas, A.; Sacadura, J.F. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)

    1996-12-31

    A formulation based on the use of the discrete ordinate method applied to the integral form of the radiant heat transfer equation is proposed for non-grey gases. The correlations between transmittances are neglected and no explicit wall reflexion is considered. The configuration analyzed consists in a flat layer of non-isothermal steam-nitrogen mixture. Cavity walls are grey with diffuse reflexion and emission. A narrow band statistical model is used to represent the radiative properties of the gas. The distribution of the radiative source term inside the cavity is calculated along two temperature profiles in a uniform steam concentration. Results obtained using this simplified approach are in good agreement with those found in the literature for the same temperature and concentration distributions. This preliminary study seems to indicate that the algorithm based on the integration of radiant heat transfer along the luminance path is less sensitive to de-correlation effects than formulations based on the differential form the the radiant heat transfer. Thus, a more systematic study of the influence of the neglecting of correlations on the integral approach is analyzed in this work. (J.S.) 16 refs.

  7. Identification et surveillance des individus

    OpenAIRE

    Aghroum, Christian; Alberganti, Michel; Bonelli, Laurent; Ceyhan, Ayse; Denis, Vincent; Dufief, Vincent; Laurent, Sébastien; Piazza, Pierre; Preuss-Laussinotte, Sylvia; Rousselin, Thierry; Thorel, Jérôme; Tsoukala, Anastassia; Vitran, Jean-Claude; Alberganti, Michel; Alberganti, Michel

    2014-01-01

    « Big Brother is watching you ! » Cet avertissement placardé sur les murs de la cité imaginaire d'Océania dans le roman 1984 de Georges Orwell peut-il s'appliquer à nos sociétés contemporaines ? Passeport biométrique, fichage informatisé des individus, multiplication des caméras de surveillance, utilisation de puce dans des objets de la vie quotidienne, ou pour suivre les criminels en liberté surveillée, les mesures d'identification, de fichage et de surveillance des individus par des techniq...

  8. Models for the control of electric actuators (EGEM, electrical engineering series); Modeles pour la commande des actionneurs electriques (Traite EGEM, serie Genie electrique)

    Energy Technology Data Exchange (ETDEWEB)

    Louis, J.P.

    2004-07-01

    The modeling of a system to be automatized is a key step for the determination of the control laws because these laws are based on inverse models deduced from direct models. The ideal example is the DC actuator, the simpleness of which allows to directly shift from the modeling to the control law. For AC actuators, the modeling tools are based on the classical hypotheses: linearity, first harmonics, symmetry. They lead to very efficient models which allow to study the properties in dynamical and permanent regime of the most important actuators: synchronous motors, asynchronous motors, voltage inverters. Some extensions to other kind of machines which does not fulfill the classical hypotheses are also proposed: synchronous machines with non-sinusoidal field distribution and asynchronous machines in saturated regime. (J.S.)

  9. La structure des solutions aqueuses

    Science.gov (United States)

    Powell, D. H.

    2003-09-01

    En commençant par l'étude par diffraction neutronique de la structure des liquides moléculaires puis de l'hydratation des ions en solution, ce cours montrera comment les principes présentés lors des cours précédents peuvent être appliqués à des systèmes aqueux. Des exemples tirés de la littérature seront utilisés pour illustrer les considérations expérimentales propre à ce domaine et le genre d'informations que nous pouvons obtenir. Ce cours montrera également l'applicaton de la diffraction neutronique à des systèmes d'intérêt biologique et environnemental et se terminera par un examen de la complémentarité fournie par la diffraction des rayons X, l'EXAFS et la RMN.

  10. peste des petits ruminants

    African Journals Online (AJOL)

    HP USER

    Diallo A, Minet C, Le Goff C, Berhe G, Albina E, Libeau. G, Barrett T (2007). The threat of peste des petits ruminants: progress in vaccine development for disease control. Vaccine. 25:5591–5597. Esuruoso GO (1995). The practice of preventive veterinary medicine in a devastated national economy. Being the text of an.

  11. Investir dan des solutions

    International Development Research Centre (IDRC) Digital Library (Canada)

    Gestion du risque. La gestion du risque est une responsabilité partagée entre les gestionnaires du Centre qui est intégrée à tous les processus administratifs importants. .... que préconisent les Normes internationales d'information financière (normes IFRS). TABLEAU 2. RÉPARTITION DES PRODUITS. Crédit parlementaire.

  12. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Plusieurs études cliniques et épidémiologiques ont montré que le diabète est associé à cette ... CMLs responsables de la modulation des fibroblastes en ..... Pagano P.J., 2004. Gene transfer of. NAD(P)H oxidase inhibitor to the vascular adventitia attenuates medial smooth muscle hypertrophy. Circ. Res., 95, 587-. 594.

  13. Praxis des Klebens

    CERN Document Server

    Theuerkauff, Petra

    1989-01-01

    Bei diesem Buch handelt es sich um einen Leitfaden fur Klebepraktiker. Es werden die verschiedenen Einzelschritte beim kleben beschrieben, als auch die vorbereitenden Massnahmen und anschliessenden Prufverfahren auf Festigkeit behandelt. Das Buch sollte an keinem Arbeitsplatz fehlen, wo man sich mit Problemen der Fugetechnik des Klebens beschaftigt.

  14. La physique des infinis

    CERN Document Server

    Bernardeau, Francis; Laplace, Sandrine; Spiro, Michel

    2013-01-01

    Écrire l'histoire de l'Univers, tel est l'objectif commun des physiciens des particules et des astrophysiciens. Pour y parvenir, deux approches s'épaulent : la voie de l'infiniment petit, que l'on emprunte via de gigantesques accélérateurs de particules, et celle de l'infiniment grand, dont le laboratoire est l'Univers. Un Univers qui est bien loin d'avoir livré tous ses secrets. On connaît à peine 4,8 % de la matière qui le constitue, le reste étant composé de matière noire (25,8 %) et d'énergie noire (69,4 %), toutes deux de nature inconnue. Et si la récente découverte du boson de Higgs valide le Modèle standard de la physique des particules, celui-ci est toujours incomplet et doit être étendu à ou dépassé. Est-on arrivé au bout du jeu de poupées russes de la matière ? Quelles sont les particules manquantes ? Faut-il revoir les lois fondamentales ? Quels instruments faut-il mettre en œuvre pour accéder à cette « nouvelle physique » ? Comment parler de Super Big Science aux citoye...

  15. REPRISE DES COURS - Yoga

    CERN Multimedia

    Club de Yoga

    2015-01-01

    REPRISE DES COURS – Venez nombreux ! Yoga, Sophrologie, Tai Chi La liste des cours pour le semestre allant du 1er septembre 2015 au 31 janvier 2016 est disponible sur notre site web : http://club-yoga.web.cern.ch Lieu Les cours ont lieu dans la salle des clubs, à l’entresol du restaurant No 2, Bât. 504 (dans la salle no 3 pour la Sophrologie). Prix des cours Le prix pour le semestre (environ 18 leçons) est fixé à 220 CHF plus 10 CHF d’adhésion annuelle au Club. Couple : 200 CHF par personne. 2 cours par semaine : 400 CHF. Inscriptions Les inscriptions aux cours seront prises directement auprès du professeur, lors de la 1ère séance. Avant de s’inscrire pour le semestre, il est possible d’essayer une séance gratuitement. Informations : http://club-yoga.web.cern.ch ----------------------------------------- cern.ch/club-yoga/

  16. Ein systemtheoretisches Modell des Verkehrsablaufs.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1972-01-01

    To determine the role of public lighting it is necessary to determine the task of the driver theoretically. However, there is not only one theory; only a general theory is in a developing stage. In this lecture a pragmatic theory for the driving task is presented. With that theory information can

  17. Recevabilité des communications par la Commission africaine des droits de l’homme et des peuples

    OpenAIRE

    Nguema, Nisrine Eba

    2014-01-01

    La Commission africaine des droits de l’homme et des peuples constitue le principal organe de protection des droits de l’homme en Afrique. Mise en place en 1987, elle a pour mission principale de recevoir les communications des victimes des violations des droits de l’homme. L’ouverture de la procédure de traitement des communications individuelles devant la Commission africaine est conditionnée par le respect des conditions posée par l’article 56 de la Charte africaine des droits de l’homme e...

  18. Représentation chimique de la structure des kérogènes et des asphaltènes en fonction de leur origine et de leur degré d'évolution Chemical Modeling of the Structure of Kerogens and Asphaltenes As a Function of Their Origin and Evolution Stage

    Directory of Open Access Journals (Sweden)

    Behar F.

    2006-11-01

    Full Text Available Dans cet article nous proposons des modèles de structures chimiques de kérogènes et d'asphaltènes de roche. Nous avons choisi de représenter les kérogènes appartenant aux trois types classiques de matières organiques aux stades d'évolution suivants : - début de la diagenèse sensu-stricto; - début de la catagenèse (formation de l'huile; - fin de la catagenèse (formation du gaz. Les asphaltènes représentés correspondent à la phase de formation de l'huile. Nous avons tenu compte des données d'analyse obtenues sur des échantillons naturels : analyse élémentaire, microscopie électronique, RMN 13C, thermogravimétrie, analyse fonctionnelle, dégradation par pyrolyse. Afin d'obtenir une représentation chimique ayant une valeur statistique suffisante, nous avons choisi une masse moléculaire de 25 000 environ, identique pour les trois kérogènes au début de la diagenèse, et une masse de 8000 environ pour les asphaltènes associés. Nous avons ensuite dessiné à l'échelle moléculaire les structures correspondantes. This paper proposes models for the chemical structures of kerogens and asphaltenes from rocks. The kerogens belonging to the three conventional types of organic matter are represented in the following stages of evolution: (1 beginning of diagenesis sensu stricto,(2 beginning of catagenesis (formation of oil, and (3 end of catagenesis (formation of gas. The asphaltenes represented here correspond to the phase of oil formation. Models are based on analytical data obtained on natural samples, i. e. elemental analysis, electron microscopy, 13C NMR, thermogravimetry, functional analysis and pyrolysis. To get enough statistical value for the chemical modelling, a same molecular mass of about 25 000 was chosen for the three kerogens at the beginning of diagenesis. A molecular mass of about 8000 was chosen for the related asphaltenes. The chemical structures were then constructed at the molecular scale.

  19. Semiconductor device models for circuit simulation power electronics; Modeles de composants semiconducteurs pour la simulation des circuits en electronique de puissance

    Energy Technology Data Exchange (ETDEWEB)

    Berraies, M.O.

    1998-09-10

    In this thesis, an alternative strategy based on a regional approach to modeling and a new partition of the model library in the simulation is proposed. The main objective is to substitute for the usual concept of `one device, on model` that of an adaptable assembly of a limited number of submodels associated with well-identified regions of semiconductor structures. In other words, the library will only contain the primitive building-blocks of the power device models. This strategy guarantees the compatibility of the various semiconductor models in terms of physical concepts, validity domain, accuracy, homogeneity of parameter identification procedures, similarly of implementation in the simulator. This approach has been applied to PIN diodes and IGBTs for experimental validation. The next step consisted on the simulation of circuit involving several interacting devices. A simple IGBT/PIN diode chopper cell has been chosen. The results obtained compare well with experiment. This demonstrates the consistency of the proposed approach. (author) 43 refs.

  20. Thure von Uexkülls semiotisches Modell des Menschen als Grundlage für eine moderne Theorie der Homöopathie

    OpenAIRE

    Schmidt, Josef M.

    2012-01-01

    Während die konventionelle moderne Medizin ihr Selbstverständnis und ihre Praxis weitgehend am Vorbild der konventionellen Naturwissenschaft orientiert, erhebt die Homöopathie den Anspruch, Patienten nicht reduktionistisch, sondern individuell und ganzheitlich zu erfassen und zu behandeln. Gemäss der Lehre Samuel Hahnemanns (1755–1843) ist dazu statt des materialistisch-mechanistischen ein semiotisch-phänomenologischer Ansatz anzuwenden. Während die Anweisungen Hahnemanns für die Praxis klar,...

  1. Injectabilite des coulis de ciment dans des milieux fissures

    Science.gov (United States)

    Mnif, Thameur

    Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

  2. Application of mixture length turbulence models in the domain of condensation; Application des modeles de turbulence de longueur de melange dans le domaine de la condensation

    Energy Technology Data Exchange (ETDEWEB)

    Louahlia, H.; Panday, P.K. [Institut de Genie Energetique, 90 - Belfort (France)

    1997-12-31

    This paper presents a comparison between turbulence models based on Prandtl theory and applied to the problem of pure fluids condensation. A theoretical model is defined which allows to determine the physical characteristics of condensation between two vertical or horizontal flat plates. The total heat flux exchanged at the wall and the mean Nusselt number are calculated using several closure models in the liquid and vapor phases. Calculation results obtained for the R123 condensation between two vertical plates show that the Pletcher`s model or the Groenwald and Kroeger`s one applied to the vapor flow and the Von Karman`s model used for the liquid film predict thermal fluxes close to the measured ones. It has been noticed also that the condensation heat transfer is underestimated in the laminar model. In the case of the R113 condensation on an horizontal flat plate, the mean Nusselt numbers estimated in the Pletcher`s model applied to both phases are close to the measurements performed by Lu and Suryanarayana. (J.S.) 12 refs.

  3. Utilisation des cahiers d'activites dans l'enseignement des sciences ...

    African Journals Online (AJOL)

    Les résultats des entretiens ont mis en exergue des sujets comme l'utilisation abusive des CA par certains enseignants, l'imposition des CA aux apprenants et leur coût, la qualité des contenus des CA et le maintien ou la suppression de la production des CA. D'autre part, le rendement scolaire des apprenants a été ...

  4. Efficacité des néonicotinoïdes et des pyréthrinoïdes utilisés contre le ...

    African Journals Online (AJOL)

    Efficacité des néonicotinoïdes et des pyréthrinoïdes utilisés contre le foreur des tiges du cacaoyer ( Eulophonotus myrmeleon Felder : Lepidoptera, Cossidae). Implications dans la stratégie de protection de la cacaoculture en Côte d'Ivoire.

  5. Dopage et protection des jeunes sportifs : Loin des affaires

    OpenAIRE

    Guy, Daniel

    2002-01-01

    National audience; Loin des affaires et des révélations polémiques de la presse, les jeunes plébiscitent massivement les activités sportives. Sport compétition, sport participation, sport détente... Pourtant, quand la pratique devient intense, que les entraînements et les compétitions s'enchaînent à un rythme soutenu, l'ombre des conduites dopantes vient déchirer la quiétude des uns et des autres. Or, que savons-nous réellement de la pratique des jeunes sportifs ? Comment préparent-ils les co...

  6. Modélisation et caractérisation des joints collés à hautes vitesses de déformation Modeling and characterization of bonded joints at high strain rates

    Directory of Open Access Journals (Sweden)

    Bourel B.

    2013-11-01

    Full Text Available Ce papier traite de la modélisation de joints collés pour les structures soumises à des sollicitations de type crash. Cette nouvelle modélisation basée sur un élément cohésif tient compte du comportement viscoplastique, de l'endommagement ainsi que de la rupture de l'adhésive. Sensible à la vitesse de déformation l'identification du critère de rupture nécessite une base expérimentale allant jusqu'à de très hautes vitesses de déformations. Un nouveau dispositif d'essais a donc été mis en place sur les barres de Hopkinson afin de solliciter des assemblages à haute vitesse et sous différents angles de chargement. This paper deals with the modeling of bonded joints for structures subjected to dynamic crash loading. This new model based on a cohesive element takes into account the viscoelastic behavior, the damage and the failure of the adhesive. Due to the strain rate sensitivity, the identification of failure criterion requires experimental tests, up to very high strain rates. A new testing device has then been set up on the Hopkinson bar in order to load the assemblies with high strain rates and with different angles.

  7. Supplementary investigations on the validation of the atmospheric radionuclide transport model (ARTM); Ergaenzende Untersuchungen zur Validierung des Atmosphaerischen Radionuklid-Transport-Modells (ARTM)

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Cornelia; Thielen, Harald; Sogalla, Martin

    2015-09-15

    In the medium-term time scale the Gaussian plume model used so far for atmospheric dispersion calculations in the General Administrative Provision (AVV) relating to Section 47 of the Radiation Protection Ordinance (StrISchV) as well as in the Incident Calculation Bases (SBG) relating to Section 49 StrISchV is to be replaced by a Lagrangian particle model. Meanwhile the Atmospheric Radionuclide Transportation Model (ARTM) is available, which allows the simulation of the atmospheric dispersion of operational releases from nuclear installations. ARTM is based on the program package AUSTAL2000 which is designed for the simulation of atmospheric dispersion of non-radioactive operational releases from industrial plants and was adapted to the application of airborne radioactive releases. The research project 3612S50007 serves, on the one hand, to validate ARTM systematically. On the other hand, the development of science and technology were investigated and, if reasonable and possible, were implemented to the program system. The dispersion model and the user interface were advanced and optimized. The program package was provided to the users as a free download. Notably t he work program comprises the validation of the approach used in ARTM to model short emission periods, which are of interest in view of the SBG. The simulation results of the diagnostic wind and turbulence model TALdia, which is part of the GO-ARTM program package, were evaluated with focus on the influence of buildings on the flow field. The user interface was upgraded with a wind field viewer. To simplify the comparison with the model still in use, a Gaussian plum e model was implemented into the graphical user interface. The ARTM web page was maintained, user questions and feedback were answered and analysed concerning possible improvements and further developments of the program package. Numerous improvements were implemented. An ARTM user workshop was hosted by the Federal Office for Radiation

  8. A Model of Secondary Hydrocarbon Migration As a Buoyancy-Driven Separate Phase Flow Un modèle de migration secondaire des hydrocarbures considéré comme un écoulement en phases séparées régi par la poussée d'Archimède

    Directory of Open Access Journals (Sweden)

    Lehner F. K.

    2006-11-01

    Full Text Available A mathematical model of secondary migration is described which permits the prediction of hydrocarbon migration and accumulation patterns in a sedimentary basin, if source rock expulsion rates and geometrical and hydraulic properties of major carrier systems are known through geological time. In this model, secondary migration is treated as buoyancy-driven, segregated flow of hydrocarbons in hydrostatic aquifers. Lateral, updip migration is conceived as a Boussinesq-type, free-surface flow, with source and sink terms representing supply from source rocks and leakage through cap rocks and faults. This permits a two-dimensional, map-view mathematical description of a three-dimensional, time-dependent secondary migration system. A nine-point finite difference approximation has been developed to minimize numerical dispersion, and upstream-weighting is used to obtain stable solutions. Example computations for simple, single carrier bed structures are presented. L'article décrit un modèle mathématique de migration secondaire prédisant la migration des hydrocarbures et leur accumulation dans un bassin sédimentaire, lorsque les taux d'expulsion des roches mères et les propriétés géométriques et hydrauliques des principaux systèmes de drainage sont connus à l'échelle du temps géologique. Dans ce modèle, la migration secondaire est traitée comme un écoulement des hydrocarbures en phase séparée, contrôlé par la poussée d'Archimède, dans des aquifères hydrostatiques. La migration latérale est considérée comme un écoulement de type Boussinesq, à surface libre, avec des termes sources et puits représentant les apports venant des roches mères et les fuites à travers les couvertures et les failles. Ceci permet une description mathématique bidimensionnelle cartographiable d'un système de migration secondaire tridimensionnel et dépendant du temps. On utilise une approximation type différences finies à neuf points pour minimiser

  9. Study of the two-dimensional Hubbard model at half-filling through constructive methods; Etude du modele de Hubbard bidimensionnel a demi remplissage par des methodes constructives

    Energy Technology Data Exchange (ETDEWEB)

    Afchain, St

    2005-02-15

    The Hubbard model is the simplest model to describe the behaviour of fermions on a network, it takes into account only fermion scattering and only interactions with other fermions located on the same site. Half-filling means that the total number of fermions is equal to half the number of sites. In the first chapter we show how we can pass trough successive approximations from a very general Hamiltonian to the Hubbard Hamiltonian. The second chapter is dedicated to the passage from the Hamiltonian formalism to the Grassmanian functional formalism. The main idea is to show that the correlation functions of the Hamiltonian approach can be described through fermionic functional integrals which implies the possibility of speaking of the model in terms of field theory. The chapter 3 deals with the main constructive techniques that allow the strict and consistent construction of models inside the frame of field theory. We show by proving the violation of a condition concerning self-energy, that the two-dimensional Hubbard model at half-filling has not the behaviour of a Fermi liquid in the Landau's interpretation. (A.C.)

  10. A gas dynamics scheme for a two moments model of radiative transfer; Un schema de type dynamique des gaz pour un modele a deux moments en transfert radiatif

    Energy Technology Data Exchange (ETDEWEB)

    Buet, Ch.; Despres, B

    2007-07-01

    We address the discretization of the Levermore's two moments and entropy model of the radiative transfer equation. We present a new approach for the discretization of this model: first we rewrite the moment equations as a Compressible Gas Dynamics equation by introducing an additional quantity that plays the role of a density. After that we discretize using a Lagrange-projection scheme. The Lagrange-projection scheme permits us to incorporate the source terms in the fluxes of an acoustic solver in the Lagrange step, using the well-known piecewise steady approximation and thus to capture correctly the diffusion regime. Moreover we show that the discretization is entropic and preserve the flux-limited property of the moment model. Numerical examples illustrate the feasibility of our approach. (authors)

  11. Mathematical study of chemical kinetics schemes. Application to air pollution models; Etude mathematique de schemas de cinetique chimique. Application a des modeles de pollution atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Billette, E.

    1997-06-23

    Complex chemical kinetics modelling is relevant in numerous fields related to the petroleum industry, for instance engine combustion, petrochemistry and atmospheric pollution. Many numerical difficulties are encountered in the computation of these models, mainly due to the large size, the non-linearity and the stiffness of the associated ordinary differential systems. We first studied systems that have an asymptotic behaviour which may be derived from an algebraic analysis. Then we reviewed different methods that make possible the reduction of size and stiffness for chemical kinetics-related differential systems, and suggest possible improvements for some of those methods. We also studied their application to atmospheric chemistry models. Finally, we started to extend those reduction methods to partial differential systems that include, in addition to chemical kinetics, other phenomena such as species emission, advection or diffusion. (author) 44 refs.

  12. Aspects des Onychomycoses chez des patients camerounais de ...

    African Journals Online (AJOL)

    ... biologiques et évolutifs des onychomycoses chez des patients camerounais. Méthode : Il s'agit d'une étude rétrospective et descriptive menée de mars 2011 à mars 2014 dans l'unité de dermatologie de l'hôpital général de Douala (HGD), incluant des patients chez lesquels le diagnostic d'onychomycose avait été posé.

  13. Des dispositions responsables à prendre pour la protection des ...

    African Journals Online (AJOL)

    En considérant l'effet néfaste des maladies, des parasites, du changement climatique et d'autres facteurs environnementaux (les OGM par exemple) sur la survie des abeilles, la baisse de leurs populations dans certaines parties du monde ne saurait être attribuée aux seules pesticides. En plus, l'impact de ces derniers sur ...

  14. Collection d'entretiens avec des chercheurs participant à des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2014-07-07

    Jul 7, 2014 ... Entretien avec…propose des entrevues vidéos avec des chercheurs participant à des projets portant sur l'adaptation aux changements climatiques réalisés en Afrique, en Asie ainsi qu'en Amérique latine et dans les Caraïbes que le CRDI subventionne par le truchement de son programme Changements ...

  15. Etat des controverses des approches cognitive et ecologique en ...

    African Journals Online (AJOL)

    Cette revue de question vise à présenter dans le champ de l'apprentissage moteur, le sens des postulats des approches cognitive et écologique de même que les critiques formulées à leur encontre. Des documents scientifiques et articles de revues indexées et publiés dans la banque de données MEDLINE, ont été ...

  16. Determination of species activities in organic phase. Modelling of liquid-liquid extraction system using uniquac and unifac models; Determination des activites des especes en phase organique. Application d`uniquac et unifac a la modelisation des systemes d`extraction liquide-liquide

    Energy Technology Data Exchange (ETDEWEB)

    Rat, B. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche en Retraitement et en Vitrification]|[Paris-6 Univ., 75 (France)

    1998-12-31

    The aim of nuclear fuel reprocessing is to separate reusable elements, uranium and plutonium from the other elements, fission products and minor actinides. PUREX process uses liquid-liquid extraction as separation method. Numerical codes for modelling the extraction operations of PUREX process use a semi-empirical model to represent the partition of species. To improve the precision and precision and predictive nature of the models, we looked for a theoretical tool which permits to quantify medium effects, especially in the organic phase, for which few models are available. The Sergeivskii-Dannus model permits to quantify deviations from ideality in organic phase equilibrated with aqueous phase, but with parameters depending on extractant/diluent ratio. We decided to investigate UNIQUAC and UNIFAC models which permit to estimate activity coefficients in non-electrolytic phases taking account of the mutual interactions of molecules and their morphology. UNIFAC is based on UNIQUAC but molecules are considered as structural groups assemblies. Before applying these model to extraction systems, we investigate their abilities to describe simple systems, binary and ternary systems. UNIQUAC has been applied to TBP/diluent mixtures and permits to estimate activity coefficients for diluents whose interactions with TPB are very different in nature and strength. Group contribution (UNIFAC) applied to TBP/alkane mixtures permits to represent the effect of lengthening alkane chain but not the effect of branching. UNIQUAC fails to describe the TBP/diluent/water/non-extractable-salt systems in case of strong TBP diluent interactions. In order to obtain a correct description of these systems, we used the Chem-UNIFAC model, where the INIFAC equation is supplemented with chemical equilibria allowing explicitly for complexes formation and where group contribution is used to describes complexes. We have with Chem-UNIFAC a model available which can take the effect of the diluent into

  17. Fourrages ligneux des savanes du Tchad : Etat actuel des ...

    African Journals Online (AJOL)

    Une meilleure méthode d'aménagement et de gestion des ligneux fourragers en vue de leur utilisation optimale a été proposée. Mots clés ...... Toutefois, la présence massive des rejets de souches observée au niveau des classes supérieures à [0-0,5 m[ est une forme d'adaptation et une stratégie de survie des espèces ...

  18. Underwater behaviour of bitumen coated radioactive wastes: experimental validation of the Colonbo degradation model; Comportement sous eau des dechets radioactifs bitumes: validation experimentale du modele de degradation Colonbo

    Energy Technology Data Exchange (ETDEWEB)

    Gwinner, B

    2004-03-01

    In the release scenario considered for geologic repository, water is thought to be the main aggressive agent with regards to bituminized radioactive waste (composed in general of 60 weight % of bitumen, 40% of soluble/insoluble salts and a few ppm of radionuclides). Since liquid water can diffuse in pure bitumen, leaching of bituminized waste results in the dissolution of the most soluble salts and leads to the development of a more or less concentrated saline solution-filled pore structure (called permeable layer). In consequence of the generation of a porous layer in the bituminized waste, leaching of salts and radionuclides can then take place. Research performed at the Atomic Energy Commission (CEA) aims therefore at understanding the consequences of ground-water immersion on the transport properties and radionuclides leaching of bituminized waste materials. To this end, a constitutive model (called COLONBO) which describes mathematically the leaching of bituminized waste has been developed. The COLONBO model is based on the following assumptions: 1. Water and dissolved salts migrate in the permeable layer according to Fick's first law. The diffusion of water and salts are quantified by effective diffusion coefficients which are unknown. 2. The mechanical properties of the bitumen matrix are not considered during leaching (free swelling). Up to now, the COLONBO model has been used only to model experimental water uptake and salt leach curves, leading (theoretical) estimates of the effective diffusion coefficients of water and salts in the permeable layer. The aim of this work was to validate experimentally the numerical results obtained with the COLONBO model. First, the correspondence between experimental and simulated water uptake and salt leach rates obtained on various bituminized waste materials is checked, leading estimates of the effective diffusion coefficients of water and salts in the permeable layer. Second, the evolution of the thickness and of

  19. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Unité de Recherche des Matériaux et des Energies Renouvelables (U.R.M.E.R). Université Abou –Baker Belkaid B.p : 119 Tlemcen 13000 Algerie. 2. Unité de Développement de la Technologie Du Silicium. UDTS, BP 399, Alger, Algérie. Accepté le : 08/06/2011. صخلم. داوﻣﻟا نﻣ ﻲﺗﻟا ﺔﺻﺎﺧو ،ﺔﻋﺎﻧﺻ يأ رﯾوطﺗ ﻲﻓ ﺎﯾﺳﯾﺋر ﻼﻣﺎﻋ ةرﯾﺧﻷا تاوﻧﺳﻟا ...

  20. Table des tableaux

    OpenAIRE

    2017-01-01

    1. District de l’Inquisition de Tolède. Distances depuis le siège 19 2. District de l’Inquisition de Tolède. Répartition de la population par régions géographiques en 1591 24 3. District de l’Inquisition de Tolède. Évolution de la population au XVIe siècle par régions géographiques 25 4. Inquisition de Tolède. Origine des étrangers vieux-chrétiens jugés par le tribunal 27 5. Inquisition de Tolède. Répartition des clercs selon le type d’agglomération 55 6. District de l’Inquisition de Tolède, ...

  1. Wave Propagation in the Effective Model of Alternating Porous and Impermeable Solid Layers Propagation des ondes dans un modèle effectif constitué de couches solides alternativement poreuses et imperméables

    Directory of Open Access Journals (Sweden)

    Molotkov L.

    2006-12-01

    Full Text Available Elastic properties of finely layered media are of great interest for seismic exploration. Theoretical models give a dependence of overall properties on constituent parameters. On the one hand they help geophysicists to estimate possible ranges of anisotropy and on the other hand they provide a basis for interpretation of measured anisotropic parameters in terms of microstructure. Last forty years such models with elastic constituents have been extensively used. Recently they have been updated for describing fractured rocks (Hsu and Schoenberg, 1993. In this case thin, and soft elastic layer models fracture. However reservoir rocks are porous and permeable. Porosity and permeability are taken into account by well-known Biot model. Finely layered porous sequences have some distinctive properties which are the topic of modern research (Schoenberg, 1996. Therefore it is important to update developed concepts to porous medium. Bakulin and Molotkov (1998, 1997 who generalized Backus averaging on poroelastic medium have done first step. Here we pay attention to one special case when there is only one preferential direction of fluid flow in porous rock. This may be caused by presence of impermeable barriers or lenses, which are modeled as set of solid layers intersecting porous medium. Such model corresponds to highly hydraulically anisotropic rock, which has very strong anisotropy of pore space structure and permeability. Les propriétés élastiques des milieux finement stratifiés présentent un grand intérêt pour l'exploration sismique. Les modèles théoriques donnent les propriétés générales en fonction des paramètres des constituants. D'une part, ils aident les géophysiciens à évaluer les gammes d'anisotropie possibles, et d'autre part, ils offrent une base pour l'interprétation des paramètres d'anisotropie mesurés en termes de microstructure. De tels modèles, élastiques, ont été largement utilisés ces quarante dernières ann

  2. Liste des figures

    OpenAIRE

    2015-01-01

    Claudine Fabre-Vassas, Identification d'un rite 1. Ordonnance de 1779 interdisant «la méthode de guérir les hernies par la castration» 66 Christian Bromberger, Pour une ethnologie du spectacle sportif 1. La popularité relative de deux vedettes de l'Olympique de Marseille 228 2. Répartition des spectateurs marseillais dans le stade d'après leur origine résidentielle 232

  3. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    7 sept. 2011 ... D‟autre part une approche statistique sera menée à partir de l‟analyse en composantes principales (ACP) afin de déterminer les processus géochimiques responsables de l‟évolution de la salinité des sols. 2. Matériel et méthodes. 2.1 Cadre physique. Le lac Fetzara est situé à 18 km au Sud-. Ouest de ...

  4. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Notre objectif est d‟élaborer des couches minces en Fe-Si par copulvérisation cathodique magnétron à différent pourcentage de silicium dans une atmosphère inerte d‟Argon et de les caractériser du point de vue physique. (composition chimique, microstructure…). Ces couches peuvent servir comme capteur magnétique.

  5. Des Ogle's old stump

    International Nuclear Information System (INIS)

    Jones, M.; Sutton, D.; Wallace, R.

    1998-01-01

    On 17 October 1997 Sylvia Bryan of RD4 Kaitaia wrote to 'Dear Somebody-Everybody' at the Anthropology Department, University of Auckland, urging further examination of an adzed stump found by Des Ogle during planting out of the Te Aupouri forest. The authors have since sought out relevant information and present it here for the interests of our readers. (author). 7 refs., 1 fig

  6. Author Details

    African Journals Online (AJOL)

    Ayite, YMXD. Vol 13, No 2 (2011): Series E - Articles Determinatin dúne application des betons de balles de riz dans le batiment au Togo Abstract · Vol 16, No 3 (2014) - Articles Influence du taux de balles de riz sur la resistance a la compression des briques en terre. Abstract. ISSN: 2413-354X. AJOL African Journals ...

  7. Study of the permeability up-scaling by direct filtering of geostatistical model; Etude du changement d'echelle des permeabilites par filtrage direct du modele geostatistique

    Energy Technology Data Exchange (ETDEWEB)

    Zargar, G.

    2005-10-15

    In this thesis, we present a new approach, which consists in directly up-scaling the geostatistical permeability distribution rather than the individual realizations. Practically, filtering techniques based on. the FFT (Fast Fourier Transform), allows us to generate geostatistical images, which sample the up-scaled distributions. In the log normal case, an equivalence hydraulic criterion is proposed, allowing to re-estimate the geometric mean of the permeabilities. In the anisotropic case, the effective geometric mean becomes a tensor which depends on the level of filtering used and it can be calculated by a method of renormalisation. Then, the method was generalized for the categorial model. Numerical tests of the method were set up for isotropic, anisotropic and categorial models, which shows good agreement with theory. (author)

  8. Climate change and land use. Towards the Nexus Land Use model; Changement climatique et usage des terres. Vers le modele Nexus Land Use

    Energy Technology Data Exchange (ETDEWEB)

    Mazas, C

    2007-07-01

    The objective of this study is to examine the impacts of arbitrations on land use (choice between urban development, agriculture, infrastructures, forests, free spaces, and so on, which are concurrent and exclusive) on greenhouse gas emissions. The first part highlights the complexity of this issue as land use can both generate important greenhouse gas emissions (through deforestation, methane emission by cattle, nitrogenous fertilizers) and absorb large quantities of CO{sub 2}. The second part analyses and discusses the extent and the reasons of deforestation, commenting the situation in developed countries and in the case of the tropical forest. The third part describes the competition between land uses, reviews existing economical models, and presents the Nexus Land Use model which could be able to integrate agricultural and forestry challenges at the planet scale.

  9. Dictionnaire des risques psychosociaux

    CERN Document Server

    Zawieja, Philippe

    2014-01-01

    Stress, suicide, harcèlement, épuisement professionnel, workaholism... Au-delà de la souffrance qu'elles désignent, ces notions souvent récentes constituent une approche inédite, et demandent à mieux être comprises, dans leur ensemble et isolément. C'est tout l'enjeu de ce dictionnaire, pionnier en son genre. Le lecteur y trouvera représentés, avec les 314 entrées (rédigées par 251 contributeurs) qui le composent, tous les champs disciplinaires s'intéressant à la souffrance au travail : psychologie du travail et des organisations, psychologie sociale et psychosociologie, psychanalyse, psychopathologie et psychiatrie, ergonomie, sociologie du travail et des organisations, médecine du travail, droit du travail et de la sécurité sociale, sciences de gestion, philosophie... Y sont détaillés les principaux concepts, notions, approches, méthodes, théories, outils, études, etc., ayant cours dans l'étude des risques psychosociaux, mais aussi certaines professions emblématiques (infirmières,...

  10. Administrateur de programme, Application des connaissances ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Supervision. Supervision directe : Consultants et personnel temporaire, au besoin. Supervision indirecte : Consultants chargés de préparer des sommaires des résultats de recherche et des communications internes, et personnel temporaire au besoin.

  11. Analysis and exploitation of bacterial population from natural uranium-rich soils: selection of a model specie; Analyse et exploitation des populations bacteriennes de sols riches en uranium: selection d'une espece modele

    Energy Technology Data Exchange (ETDEWEB)

    Mondani, L.

    2010-11-23

    It is well known that soils play a key role in controlling the mobility of toxic metals and this property is greatly influenced by indigenous bacterial communities. This study has been conducted on radioactive and controls soils, collected in natural uraniferous areas (Limousin). A physico-chemical and mineralogical analysis of soils samples was carried out.The structure of bacterial communities was estimated by Denaturing Gradient Gel Electrophoresis (DGGE). The community structure is remarkably more stable in the uranium-rich soils than in the control ones, indicating that uranium exerts a high selection from the soils was constructed and screened for uranium resistance in order to study bacteria-uranium interactions. Scanning electron microscopy revealed that a phylo-genetically diverse set of uranium-resistant species ware able to chelate uranium at the cell surface. (author) [French] On sait que les sols et les populations bacteriennes indigenes ont une influence sur la mobilite des metaux, donc sur leur toxicite. Cette etude a ete menee sur des sols uraniferes et controles collectes dans le Limousin (regions naturellement riches en uranium ). Une analyse physico-chimique et mineralogique des echantillons de sol a ete realisee. La structure des communautes bacteriennes a ete etudiee par electrophorese en gradient de denaturant (DGGE). La structure des communautes est remarquablement stable dans les sols uraniferes, ce qui indique que l'uranium exerce une forte pression de selection. D'autre part, une collection de bacteries cultivables a ete realisee a partir des sols, puis criblee pour la resistance a l'uranium, dans le but d'etudier les interactions entre bacteries et uranium. Des observations en Microscopie electronique a Balayage ont mis en evidence differents mecanismes de chelation de l'uranium a la surface cellulaire

  12. Projektmanagement in Zeiten des Wandels

    OpenAIRE

    Papesch, Gerti

    2003-01-01

    Projektmanagement in Zeiten des Wandels : 2. Fachtagung Projektmanagement, 1. Oktober 2003 / ZWW, Zentrum für Weiterbildung und Wissenstransfer. Gerhard Wilhems ... - Augsburg : ZWW, 2003. - VI, 190 S.

  13. Energy demand modelling: pointing out alternative energy sources. The example of industry in OECD countries; Modelisation de la demande d`energie: mise en evidence des substitutions energetiques. Application au secteur industriel des pays de l`OCDE

    Energy Technology Data Exchange (ETDEWEB)

    Renou, P.

    1992-02-19

    This thesis studies energy demand and alternative energy sources in OECD countries. In the first part, the principal models usually used for energy demand modelling. In the second part, the author studies the flexible functional forms (translog, generalized Leontief, generalized quadratic, Fourier) to obtain an estimation of the production function. In the third part, several examples are given, chosen in seven countries (Usa, Japan, Federal Republic of Germany, France, United Kingdom, Italy, Canada). Energy systems analysis in these countries, can help to choose models and gives informations on alternative energies. 246 refs., 24 figs., 27 tabs.

  14. Modeling Chemical EOR Processes: Some Illustrations from Lab to Reservoir Scale Modélisation des procédés EOR chimiques : du laboratoire au réservoir

    Directory of Open Access Journals (Sweden)

    Douarche F.

    2013-02-01

    Full Text Available Chemical flooding, SP (Surfactant Polymer or ASP (Alkali-Surfactant-Polymer, are of increasing interest due to the need to increase oil production. Design of chemical processes is very project specific and requires case by case studies including various steps among which reservoir data analysis, chemical formulations, coreflood validations and reservoir simulation. Every step is dependent on the preceding ones and the last reservoir simulation step gathers all the information collected during the project. In this paper, we present a chemical simulator describing two phase flow with chemical transport of alkali, surfactant, polymer and salinity. Two phase flow is related to capillary desaturation curve through the decrease of oil-water interfacial tension. Physical chemistry reactions are described either with a thermodynamic approach or a simplified one using tables or simplified physics to be compatible with large scale reservoir simulations. In this paper, we describe the simulator and present results of numerous experiments specially designed to validate the model: alkaline injections of carbonates and borates, surfactant adsorption experiments at different salinities and pH, systematic effect of salinity on interfacial tension and oil recovery with/without salinity gradient. The good agreement between the experimental and numerical oil recoveries and chemical compositions is very encouraging and supports the validity of the physics implemented in the simulator. In particular, the dominant effect of pH on adsorption and the importance of a salinity gradient on oil recovery is highlighted by numerical simulation. Finally, a sensitivity study at the reservoir scale is presented to illustrate relevant factors for the implementation of an economic surfactant-based process. Les procédés de récupération tertiaire par voie chimique, SP (Surfactant Polymer ou ASP (Alkali-Surfactant-Polymer, sont en plein essor du fait d’une demande croissante

  15. Balancing of rotating machines using influence coefficients calculated by numerical models; Equilibrage des machines tournantes par coefficients d`influence a l`aide de modeles numeriques

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, R.; Bigret, R.; Karajani, R.; Vialard, S.

    1995-09-01

    The balancing of large rotating machines (turbine-generator sets and reactor coolant pumps) is generally carried out at Electricite de France using a influence coefficient method. For this, the influence of unbalances in the balancing planes have to be ascertained and, as a consequence, involves stopping and starting the machines several times. The purpose of the presented study is to analyse the possibility of reducing machine unavailability through the use of influence coefficients calculated with the help of a adjusted numerical (unbalance response) model for the balancing process. The principles of this method are shown and applied to a mock-up of a shaft line fitted with a full set of instruments (bearings and shaft) and having modal characteristics similar to common machines. The results are encouraging. They show the feasibility of the method.

  16. From the validation of the standard model to the search for gravitational waves; Des tests du modele standard a la recherche d'ondes gravitationnelles

    Energy Technology Data Exchange (ETDEWEB)

    Tournefier, E

    2006-09-15

    The author reviews his activities concerning particle physics at Lep and LHC (Large Hadron Collider - CERN) and his latest works in the domain of gravitational waves. He has contributed first to the measurement of the parameters of the Z boson resonance and then to the extraction from experimental data of the standard model parameters like boson Higgs mass, top quark mass or the strong coupling constant. He has also worked on the development and testing of a LHC detector that will be useful to search for the Higgs boson via its decay in 2 photons. The Virgo experiment aims at detecting gravitational waves through interferometry, the author describes his contribution to the design of the detection system and gives a detailed review of the expected technical background noises. (A.C.)

  17. Micro-seismicity induced by hydrocarbon production: contribution to localization of events and identification of the source mechanisms through the use of dynamic friction models; Contribution a la localisation des evenements et l'identification des mecanismes au foyer en micro-sismicite induite par l'exploitation d'hydrocarbures. Utilisation des modeles de frottement dynamique

    Energy Technology Data Exchange (ETDEWEB)

    Mohammedi, H.

    2002-11-01

    Oil production or any injection of fluid in a geological medium is likely to impose variations of stresses which might generate micro-seismicity. We examine whether the use of dynamic friction models could allow for a better determination of mechanics on the fault plane from borehole seismometers. We sought to identify the friction law model from seismogram observation. Before dealing with this inverse problem, we examined the direct problem generating synthetic seismograms at virtual stations, on the basis of a postulated friction law using the FD3D earthquake simulation code and the AXITRA radiation computation code. Treatment of two different laws, one of which is an original variation of the Dietrich-Ruina law, leads to similar seismograms. This might indicate that systematic inversion for the friction law only from seismogram observation might reveal difficult. (authors)

  18. Meconnaissance des traumatismes des voies urinaires dans un ...

    African Journals Online (AJOL)

    Meconnaissance des traumatismes des voies urinaires dans un contexte de poly traumatisme: a propos de deux observations. ... They insist on good clinical assessment of abdominal trauma doubled the achievement of imaging tests to not overlook lesions of the urinary tract that can put patient's life threatening. Keywords: ...

  19. Composition chimique et effet Acaricide des huiles essentielles des ...

    African Journals Online (AJOL)

    La composition chimique et l\\'effet acaricide des huiles essentielles des feuilles de Chenopodium ambrosioides et Eucalyptus saligna vis-à-vis de Rhipicephalus lunulatus ont été évalués au Laboratoire de Chimie Appliquée et Environnementale de l\\'Université de Dschang dans l\\'Ouest du Cameroun. Cinq doses de ...

  20. Culture du bambou : diversification des moyens de subsistance des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Culture du bambou : diversification des moyens de subsistance des petits producteurs de tabac du sud de la province de Nyanza, au Kenya - phase II. Au cours de la première phase du projet (projet no 103765), les chercheurs ont effectué une analyse de marché pour le bambou et les produits du bambou, comparé les ...

  1. Diversification des moyens de subsistance des petits producteurs de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    L'économie du Malawi repose essentiellement sur la culture du tabac, qui représente plus de 70 % des revenus d'exportation. Pour 60 % des 100 000 membres de la National Smallholder Farmers' Association of Malawi (NASFAM), le tabac est la seule et unique source de revenus. Les cultivateurs de tabac, au Malawi ...

  2. Etude des interactions entre les differents acteurs des interventions ...

    African Journals Online (AJOL)

    Etude des interactions entre les differents acteurs des interventions sous directives communautaires et changements obtenus au Benin et au Togo. P.V. Malou Adom, Ch. P. Makoutode, T Gnaro, A.R. Ouro-Koura, E.M. Ouendo, G Napo-Koura, M Makoutode ...

  3. Effets des biomasses vertes de Tithonia diversifolia et des engrais ...

    African Journals Online (AJOL)

    Innovation (MINRESI) pour avoir financé l'intégralité des activités relatives à cette étude. RESUME. L'amélioration de la productivité des sols ferralitiques en zone forestière peut être possible grâce aux intrants locaux en complément à la fertilisation ...

  4. Gestion des ressources naturelles : des solutions avantageuses à ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    environnement et l'accès aux ressources naturelles est un enjeu crucial. Ces 40 dernières années, des chercheurs appuyés par le CRDI ont trouvé des moyens novateurs de réduire la pauvreté tout en protégeant les ressources naturelles dont ...

  5. La recherche en action : des solutions locales, des effets durables ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    15 déc. 2010 ... Le Centre de recherches pour le développement international (CRDI) appuie la production et l'application de connaissances qui améliorent de façon notable la situation des habitants des pays en développement.

  6. Roles et taches des accompagnateurs des patients hospitalises ...

    African Journals Online (AJOL)

    Roles et taches des accompagnateurs des patients hospitalises dans le service de pneumo-phtysiologie au Centre Hospitalier Universitaire Yalgado Ouedraogo de ... Logistical support represented by material support, drug supply, cleaning of premises, and littering occupied respectively 100%, 91%, 42% and 73%.

  7. Electromagnetic and thermal modelling of induction motors, by accounting for space harmonics; Modelisation electromagnetique et thermique des moteurs a induction, en tenant compte des harmoniques d'espace

    Energy Technology Data Exchange (ETDEWEB)

    Mezani, S.

    2004-07-15

    This work is interested in the study of the electromagnetic and thermal behaviors of the induction motor. A state of the art is initially drawn up, where we have presented and discussed the current methods dealing with electromagnetic and thermal modeling of induction motors. An electromagnetic model, that uses the 2D complex finite element method to solve the field equations, is developed. The rotor movement is accounted for by coupling the air gap field, for each space harmonic, using the double air gap method. The superposition principle permits the determination of the final solution. To deal with non linear problems, an approach that introduces equivalent reluctivities, is proposed. We have assumed that the saturation is only due to the first space harmonic. A thermal model is elaborated by using the nodal method. The machine is cut up into 11 cylindrical lumped elements, the thermal model represents the juxtaposition of these lumped elements. The electromagnetic and thermal models are, weakly, coupled together for a more precise determination of the temperature distribution inside the motor. In the validation phase of our work, we have designed a test bench that allows specific torque and temperature measurements. The comparison of the calculations and the measurements is satisfactory. (author)

  8. Etude des phenomenes dynamiques ultrarapides et des caracteristiques impulsionnelles d'emission terahertz du supraconducteur YBCO

    Science.gov (United States)

    Savard, Stephane

    Les premieres etudes d'antennes a base de supraconducteurs a haute temperature critique emettant une impulsion electromagnetique dont le contenu en frequence se situe dans le domaine terahertz remontent a 1996. Une antenne supraconductrice est formee d'un micro-pont d'une couche mince supraconductrice sur lequel un courant continu est applique. Un faisceau laser dans le visible est focalise sur le micro-pont et place le supraconducteur dans un etat hors-equilibre ou des paires sont brisees. Grace a la relaxation des quasiparticules en surplus et eventuellement de la reformation des paires supraconductrices, nous pouvons etudier la nature de la supraconductivite. L'analyse de la cinetique temporelle du champ electromagnetique emis par une telle antenne terahertz supraconductrice s'est averee utile pour decrire qualitativement les caracteristiques de celle-ci en fonction des parametres d'operation tels que le courant applique, la temperature et la puissance d'excitation. La comprehension de l'etat hors-equilibre est la cle pour comprendre le fonctionnement des antennes terahertz supraconductrices a haute temperature critique. Dans le but de comprendre ultimement cet etat hors-equilibre, nous avions besoin d'une methode et d'un modele pour extraire de facon plus systematique les proprietes intrinseques du materiau qui compose l'antenne terahertz a partir des caracteristiques d'emission de celle-ci. Nous avons developpe une procedure pour calibrer le spectrometre dans le domaine temporel en utilisant des antennes terahertz de GaAs bombarde aux protons H+ comme emetteur et detecteur. Une fois le montage calibre, nous y avons insere une antenne emettrice dipolaire de YBa 2Cu3O7-delta . Un modele avec des fonctions exponentielles de montee et de descente du signal est utilise pour lisser le spectre du champ electromagnetique de l'antenne de YBa 2Cu3O7-delta, ce qui nous permet d'extraire les proprietes intrinseques de ce dernier. Pour confirmer la validite du modele

  9. La diffraction des neutrons et des rayons X pour l'étude structurale des liquides et des verres

    Science.gov (United States)

    Fischer, H. E.; Salmon, P. S.; Barnes, A. C.

    2003-02-01

    La compréhension de mainte propriété physique d'un verre ou d'un liquide nécessite la connaissance des facteurs de structure partiels (PSFs) qui décrivent chacun la distribution d'une espèce atomique autour d'une autre. La technique de diffraction des neutrons avec substitution isotopique (NDIS) [1,2,3], ayant bien réussi a déterminer les PSFs de certains composés [4,5], est pourtant restreinte aux isotopes présentant un contraste suffisant en longueur de diffusion. D'un autre cote, la technique de diffusion anomale des rayons X (AXS ou AXD) [6] permet de faire varier la longueur de diffusion d'une espèce atomique pourvu que son énergie d'absorption soit à la fois accessible et suffisamment élevée pour donner un assez grand transfert du moment. La combinaison des techniques de diffraction des neutrons (avec ou sans substitution isotopique) et de diffraction des rayons X (avec ou sans diffusion anomale) peut donc permettre d'obtenir un meilleur contraste en longueurs de diffusion pour un système donné, mais exige une analyse de données plus soignée pour pouvoir bien tenir compte des erreurs systématiques qui sont différentes pour les 2 techniques [7]. Pour les atomes ayant des distributions électroniques quasi-sphériques, e.g. dans le cas d'un alliage liquide, la combinaison des techniques de NDIS et de diffraction des rayons X s'est déjà montrée très avantageuse pour la détermination des PSFs [8,9]. Dans le cas des verres ayant d'importantes liaisons covalentes, l'effective combinaison des 2 techniques peut être moins directe mais facilitée lorsqu'il s'agit des atomes de grand Z [10,11]. Nous présentons ici un sommaire du méthode et quelques exemples des résultats.

  10. Modélisation de la combustion de fuels lourds prenant en compte la dispersion des asphaltènes Modeling Heavy Fuel-Oil Combustion (While Considering Or Including Asphaltene Dispersion

    Directory of Open Access Journals (Sweden)

    Audibert F.

    2006-11-01

    difficultés relevant du mode d'exploration et de la non adéquation entre les structures asphalténiques et fractales. On a finalement opté pour une détermination visuelle s'appuyant sur les clichés sur lesquels les agglomérats d'asphaltènes sont clairement visualisés tels qu'ils sont dans le fuel. Ce mode d'exploration laborieux a cependant permis de déterminer un modèle construit sur une série de 25 fuels dont 10 ont été brûlés sur une chaudière de 2 MW, et 15 sur un four de 100 kW. Ce modèle fait intervenir les teneurs en carbone Conradson et en métaux, ainsi que le taux de dispersion des asphaltènes. Le perfectionnement des moyens d'exploration aidant, on peut s'attendre à ce que soient disponibles des techniques d'évaluation de la dispersion sur les clichés. Ce paramètre pourra alors être pris en considération pour une meilleure prédiction de résultats de combustion insuffisamment expliqués avec les paramètres classiques. Various models aiming to predict the amount of unburned particles (solids during heavy fuel-oil combustion have been developed. The parameters taken into consideration are generally asphaltenes precipitated by normal heptane or pentane and Conradson carbon as well as the metals content having a known catalytic effect on cenosphere combustion in the combustion chamber. The Exxon and Shell models can be mentioned, which were developed respectively in 1979 and 1981 (Chapter II. Other models also give consideration to the fuel-oil composition, the way it is atomized and diffused in the chamber and the combustion kinetics (research done by the MIT Energy Laboratory published in 1986. However, the above parameters are not the only ones involved. For some fuel oils, experience has shown that the state of dispersion of asphaltenes may also play an important role particularly for combustion installations with mechanical injection for which the dispersion of fuel-oil droplets is not very great and does not affect the structures built

  11. Assimilation of Polder aerosol optical thickness into LMD2-Inca model in order to study aerosol-climate interactions; Etude des interactions entre aerosols et climat: assimilation des observations spatiales de Polder dans LMDz-Inca

    Energy Technology Data Exchange (ETDEWEB)

    Generoso, S.

    2004-12-15

    Aerosols influence the Earth radiative budget both through their direct (scattering and absorption of solar radiation) and indirect (impacts on cloud microphysics) effects. The anthropogenic perturbation due to aerosol emissions is of the same order of magnitude than the one due to greenhouse gases, but less well known. To improve our knowledge, we need to better know aerosol spatial and temporal distributions. Indeed, aerosol modeling still suffers from large uncertainties in sources and transport, while satellite observations are incomplete (no detection in the presence of clouds, no information on the vertical distribution or on the chemical nature). Moreover, field campaigns are localized in space and time. This study aims to reduce uncertainties in aerosol distributions, developing assimilation of satellite data into a chemical transport model. The basic idea is to combine information obtained from spatial observation (optical thickness) and modeling studies (aerosol types, vertical distribution). In this study, we assimilate data from the POLDER space-borne instrument into the LMDz-INCA model. The results show the advantage of merging information from different sources. In many regions, the method reduces uncertainties on aerosol distribution (reduction of RMS error). An application of the method to the study of aerosol impact on cloud microphysics is shown. (author)

  12. Modeling of gas condensates properties using continuous distribution functions for the characterization of the plus fraction; Modelisation des proprietes thermodynamiques des gaz a condensat par representation de la fraction lourde a l`aide de fonctions de distribution

    Energy Technology Data Exchange (ETDEWEB)

    Sportisse, M.

    1996-12-20

    The modeling of thermodynamic behaviour for gas condensates is not yet satisfactory and it involves an adjustment of thermodynamic models. We propose here a fitting based on the characterization of the plus fraction using three continuous distribution functions associated to the following families: n-alkanes, n-alkylbenzenes and poly-aromatics. No continuous thermodynamic model is used and PVT calculations are made with the Peng-Robinson equation of state. For poly-aromatics, a simple correlation of {l_brace} T{sub c}, P{sub c}, {omega} {r_brace} is given. The parameters of the distributions are fitted in order to improve the accuracy of the liquid deposit curve calculation. A continuous minimization by simulated annealing has been used to avoid local minima. Good results on fitting PVT properties have been obtained with more than twenty gas condensates from different areas. Moreover, the prediction of tank liquid and heavy-plus fraction densities are given with an average deviation of 1.2 % and 3.6 %. Tests on temperature extrapolation show that our modeling yields a good representation of pressure and temperature influence on gas condensates behaviour. (author) 89 refs.

  13. Adsorption of gaseous pollutants on activated carbon filters. Modelling of the coupled exchanges of heat and mass; Adsorption de polluants gazeux sur des filtres de charbon actif. Modelisation des echanges couples de matiere et de chaleur

    Energy Technology Data Exchange (ETDEWEB)

    Fiani, E.

    2000-01-27

    The aim of this work is to remove gasoline and odorous molecules vapors. Thermodynamics and kinetics studies have been carried out; they concern the fixation of representative gases on activated carbons. Hydrogen sulfide and n-butane are chosen to represent the odorous molecules. Different activated carbons are considered: only the adsorbent impregnated by KOH has satisfying performance. The adsorption of hydrocarbons on a granulated activated carbon is studied on four original devices specifically perfected for this work: gravimetry, calorimetry, thermal measurements and gaseous phase chromatography. The gravimetric measurements are coupled to thermal measurements inside the granulates. Strong temperature variations have then been observed inside a granulate during the adsorption. These experimental results have been taken into account to adapt the classical Langmuir kinetic model. This new model allows to predict all the curves: setting / internal temperature variation for the adsorption of the hydrocarbons alone. The competitive nature of the adsorption sites allows then to explain qualitatively the adsorption of binary mixtures of hydrocarbons. At last, the classical Langmuir model allows to explain correctly the thermodynamic results, for the hydrocarbons alone or in binary mixture. The proposed modelling allows then to treat both on a kinetic and thermodynamic way the case of a non isothermal adsorption at the scale of an activated carbon granulate and to predict the phenomena at the filter scale. (O.M.)

  14. La cogestion des Ressources naturelles

    International Development Research Centre (IDRC) Digital Library (Canada)

    Comprend des réf. bibliogr. ISBN 1-55250-329-1. 1. Cogestion des ressources naturelles—Pays en voie de développement—Cas, Études de. 2. Conservation ...... De fait, les villageois en imputaient la faute aux fonctionnaires nationaux et locaux qui n'avaient pas su mettre efficacement en oeuvre les politiques forestières.

  15. Global Methodology to Integrate Innovative Models for Electric Motors in Complete Vehicle Simulators Méthodologie générale d’intégration de modèles innovants de moteurs électriques dans des simulateurs véhicules complets

    Directory of Open Access Journals (Sweden)

    Abdelli A.

    2011-11-01

    . Comment reduire les emissions moyennes de CO2 des vehicules particuliers a 120 g/km en 2012 et 95 g/km en 2020 comme le prevoit l’accord conclu entre la Commission Europeenne et les constructeurs europeens ? Cette question a reponses multiples preoccupe a l’heure actuelle l’ensemble du monde automobile. L’electrification des vehicules semble etre une des solutions les plus pertinentes, ce qui pousse les constructeurs a envisager des vehicules hybrides de plus en plus innovants. Cette solution, theoriquement tres interessante, complexifie encore un peu plus les groupes moto-propulseurs des vehicules, ce qui necessite l’utilisation d’outils de simulation adequats pour reduire les couts et les durees de developpement. La simulation systeme, outil deja primordial dans le processus de developpement des moteurs a combustion interne, devient alors incontournable. Pour etudier ce type d’architectures hybrides complexes, et a l’instar des modeles physiques developpes pour le moteur a combustion interne, la simulation systeme doit se doter de modeles predictifs comparables pour les machines electriques. Des leurs specifications, ces modeles doivent integrer certaines contraintes tres exigeantes sur les temps de simulation, contrainte garantissant par la suite une plus large utilisation des simulateurs, notamment pour le developpement et la validation de strategies de controle. L’objectif de ce papier est donc de presenter une methodologie generale de developpement de modeles de machines electriques, modeles ayant pour objectif final d’etre integres dans un simulateur vehicule complet. Cette methodologie met en scene differents types de modelisations (modeles elements finis, modeles de caracterisation, modele de simulation permettant un compromis temps de calcul – precision adequat. Cette methodologie a ete deployee avec succes pour la modelisation d’un moteur synchrone a aimants permanents. A l’issue du processus de modelisation, ce dernier a ete integre

  16. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    diabète et le tabagisme sont des facteurs de risque reconnus [2-4]. Les données épidémiologiques recueillies au cours de ces trente dernières années laissent ... réduction d‟expression du gène LOX-1 et de la libération de TNFα stimulée par les. LDL-oxydées [22]. Chez l‟homme, in vivo, Voutilainen et al. [23] ont mis en ...

  17. COMPLICATIONS CHIRURGICALES DES AVORTEMENTS ...

    African Journals Online (AJOL)

    1 janv. 2004 ... liquide purulent, sérosanguinolent, ou fécaloïde. Les lésions retrouvées étaient classées en lésions utérines et annexielles (Tableau I), lésions ... femmes par an dans le Monde d'après l'Organisation. Mondiale de la Santé [15]. Leur fréquence élevée dans notre série impose une prise systématique des ...

  18. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    Revue Synthèse N° 22, Décembre 2010. N. Benrachou et al. 19. Tableau 3. Composition en triglycérides des trois huiles d'olive). Blanquette. Limli. Bouricha. Variétés. Triglycérides. N° pic. NCE. 3,24 ± 0,01. 2,86± 0,02. 1,06 ± 0,03. LLL. 1. 42. 2,97 ± 0,01. 2,15 ± 0,07. 1,71 ± 0,06. OLLn +PoLL. 2. 0,21 ± 0,01. 0,66 ± 0,02.

  19. Liste des auteurs

    OpenAIRE

    2016-01-01

    Garry Apgar The Voltair Society of America, New York Jean Balcou Université de Bretagne occidentale, Brest Annie Becq Université de Caen Paul Benhamou. Purdue University, West Lafayette, Indiana Reed Benhamou Indiana University, Bloomington, Indiana Jacqueline Biard-Millerioux Université de Poitiers Françoise Bléchet Bibliothèque nationale de France, département des manuscrits, Paris Nicolas Brucker Université de Metz Else-Marie Bukdahl The Royal Danish Academy of Fine Art, Copenhague Christo...

  20. Gestion des ressources naturelles

    International Development Research Centre (IDRC) Digital Library (Canada)

    Mais la situation évolue grâce aux travaux du Réseau international sur le bam- bou et le rotin (INBAR), créé par le CRDI dans les années 1990. À Allahabad, en Inde, la culture du bam- bou a permis de rétablir la fertilité des sols dégradés par l'extraction de l'argile nécessaire à la fabrication de briques, et les agriculteurs.

  1. 3D modeling of stratigraphic units and simulation of seismic facies in the Lion gulf margin; Modelisation 3D des unites stratigraphiques et simulation des facies sismiques dans la marge du golfe du Lion

    Energy Technology Data Exchange (ETDEWEB)

    Chihi, H.

    1997-05-12

    This work aims at providing a contribution to the studies carried out on reservoir characterization by use of seismic data. The study mainly consisted in the use of geostatistical methods in order to model the geometry of stratigraphic units of the Golfe du Lion margin and to simulate the seismic facies from high resolution seismic data. We propose, for the geometric modelling, a methodology based on the estimation of the surfaces and calculation afterwards of the thicknesses, if the modelling of the depth is possible. On the other hand the method consists in estimating the thickness variable directly and in deducing the boundary surfaces afterwards. In order to simulate the distribution of seismic facies within the units of the western domain, we used the truncated Gaussian method. The used approach gave a satisfactory results, when the seismic facies present slightly dipping reflectors with respect to the reference level. Otherwise the method reaches its limits because of the problems of definition of a reference level which allows to follow the clino-forms. In spite of these difficulties, this simulation allows us to estimate the distribution of seismic facies within the units and then to deduce their probable extension. (author) 150 refs.

  2. Heat and mass transfer in multi-scale porous structures: application to Diesel particulate filters modelling; Transferts de chaleur et de masse dans des structures poreuses multi-echelles: application a l'etude des filtres a particules Diesel

    Energy Technology Data Exchange (ETDEWEB)

    Oxarango, L.

    2004-09-15

    Ceramic filters appear to be the most promising solution to deal with the future emission standard requirements for diesel powered vehicles. Indeed, this type of Diesel Particulate Filters provides suitable characteristics for high efficiency soot collection. However, this filtration process is characterised by a dramatic increase of the pressure drop imposed in the exhaust line. Thus, the filter has to be cleaned periodically to insure the proper engine operating conditions. This regeneration phase is based on the oxidation of the carbon particles within the apparatus. This complex thermal process is critical for the safety working of Diesel Particulate Filters. Indeed, thermal stresses induced by the heat released during soot oxidation are involved in most of the filter breaking scenario. Numerous geometrical parameters defining the complex multi-scale structure of the apparatus could influence its thermal response. Thus, the geometrical optimization of these filters is a major problematic for the development of new products. This study aims at modelling heat and mass transfer phenomenon within Diesel Particulate Filters. The studied geometrical configuration is based on a ceramic honeycomb with porous walls and alternately plugged channel known as wall-flow DPF. In a first part, the gas flow, particles transport and collection are considered. Given the apparatus particular structure, the problem has to be treated considering various spatial length-scales. The filtering walls are characterised by a micrometric porous structure. The flow modelling with the Darcy law requires determining a particular effective permeability. The laminar flow problem in millimetric channels with wall suction (or injection) is studied. The asymptotic solution for flow in two-dimensional channels is used to derive a one-dimensional system preserving mass and momentum balances. This approach is then extended to the square channel configuration using direct numerical simulations. The

  3. Modelisations des effets de surface sur les jets horizontaux subsoniques d'hydrogene et de methane

    Science.gov (United States)

    Gomez, Luis Fernando

    Le developpement des codes et de normes bases sur une methodologie scientifique requiert la capacite de predire l'etendue inflammable de deversements gazeux d'hydrogene sous differentes conditions. Des etudes anterieures ont deja etabli des modeles bases sur les lois de conservation de la mecanique des fluides basees sur des correlations experimentales qui permettent de predire la decroissance de la concentration et de la vitesse d'un gaz le long de l'axe d'un jet libre vertical. Cette etude s'interesse aux effets de proximite a une surface horizontale parallele sur un jet turbulent. Nous nous interessons a son impact sur l'etendue du champ de la concentration et sur l'enveloppe inflammable en particulier. Cette etude est comparative : l'hydrogene est compare au methane. Ceci permet de degager l'influence des effets de difference de la densite sur le comportement du jet, et de comparer le comportement de l'hydrogene aux correlations experimentales, qui ont ete essentiellement etablies pour le methane. Un modele decrivant l'evolution spatio-temporelle du champ de concentration du gaz dilue est propose, base sur la mecanique des fluides computationnelle. Cette approche permet de varier systematiquement les conditions aux frontieres (proximite du jet a la surface, par exemple) et de connaitre en detail les proprietes de l'ecoulement. Le modele est implemente dans le code de simulations par volumes finis de FLUENT. Les resultats des simulations sont compares avec les lois de similitudes decoulant de la theorie des jets d'ecoulements turbulents libres ainsi qu'avec les resultats experimentaux disponibles. L'effet de la difference des masses molaires des constituantes du jet et des constituantes du milieu de dispersion est egalement etudie dans le contexte du comportement d'echelle de la region developpee du jet.

  4. Graph Machine Based-QSAR Approach for Modeling Thermodynamic Properties of Amines: Application to CO2 Capture in Postcombustion Approche QSAR Graph Machines pour la modélisation des propriétés thermodynamiques des amines : application au captage du CO2 en postcombustion

    Directory of Open Access Journals (Sweden)

    Porcheron F.

    2013-03-01

    Full Text Available Amine scrubbing is usually considered as the most efficient technology for CO2 mitigation through postcombustion Carbon Capture and Storage (CCS. However, optimization of the amine structure to improve the solvent properties requires to sample a large number of possible candidates and hence to gather a large amount of experimental data. In this context, the use of QSAR (Quantitative Structure Activity Relationship statistical modeling is a powerful tool as it performs a mapping of a set of input vectors (i.e. the characteristics or the properties of the molecules under consideration to a set of output vectors (i.e. their targeted properties. In this work, we used a high throughput screening experimental device to measure CO2 solubility data on a set of 46 amine aqueous solutions. Absorption isotherms are represented using a thermodynamic model based on two thermodynamic constants, pKa*  and pKc* , accounting for the main chemical reactions occurring in the liquid phase between amine and CO2. Then, we used a statistical approach named Graph Machines at the same time to cluster the molecules and to model the variation of the acidity constant pKa*  as a function of the molecular structure. The originality of our approach is the use of graphs to represent molecules in multidimensional spaces and simultaneously construct predictive models of their physicochemical properties based on these graphs. This approach is applied in this paper to predict the thermodynamic properties of a set of 5 new molecules. Le procédé d’absorption aux amines est considéré comme la technologie la plus efficace pour limiter les rejets de CO2 dans le cadre du captage en postcombustion puis du stockage du CO2. Cependant, l’optimisation des propriétés du solvant nécessite d’évaluer un grand nombre de candidats potentiels et donc de collecter une quantité importante de propriétés expérimentales. Dans ce contexte, l’utilisation de méthodes de mod

  5. Utilisation sans risque des eaux usées, des excréta et des eaux ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les responsables de ce projet piloteront l'application et l'adaptation des principes directeurs relatifs à l'utilisation sans risque des eaux usées, des excreta et des eaux grises en agriculture et en aquaculture (Guidelines for the Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture), que ...

  6. Thermal Evolution of Crude Oils in Sedimentary Basins: Experimental Simulation in a Confined System and Kinetic Modeling Evolution thermique des huiles dans les bassins sédimentaires : simulation expérimentale par pyrolyse en milieu confiné et modélisation cinétique

    Directory of Open Access Journals (Sweden)

    Behar F.

    2006-11-01

    coefficients alphaij were optimized with reference to a dataset comprising the final compositions resulting from oil pyrolysis experiments. This optimization was carried out successively on each distillate and each residue, on both distillate and residue from the same oil, then on the two distillates and two residues altogether. The model accounts satisfactorily for the specific kinetics of cracking of both each oil and of the two oils together, suggesting that it is now possible to predict the thermal behavior of a given oil provided the proportions of the ten fractions selected for the model are known. The wide temperature range in which the model is valid, supports its extrapolation to the temperature range of sedimentary basins. Une meilleure connaissance des mécanismes du craquage thermique des huiles doit permettre de mieux comprendre leur évolution naturelle dans les bassins sédimentaires et donc d'améliorer les modèles actuels utilisés pour prédire la formation du gaz. Bien que les mécanismes de craquage soient bien connus pour des composés modèles ou des mélanges simples d'hydrocarbures, il n'existe pas à l'heure actuelle, à l'exception des modèles empiriques, de méthode pour rendre compte de la dégradation thermique des mélanges complexes, surtout, lorsque ces derniers sont enrichis en produits lourds. Au cours du craquage thermique, une huile produira à la fois des composés plus légers et des composés plus lourds que la charge initiale. En conséquence, les produits de pyrolyse seront un mélange complexe contenant des produits nouveaux et des composés non encore dégradés. Afin de pouvoir faire la distinction entre réactifs et produits, nous avons choisi de fractionner chaque huile en deux grandes fractions : la première (distillat 300- contenant des hydrocarbures légers de C6 à C16 et la seconde (résidu 300+ contenant des hydrocarbures et des produits polaires. Afin de simuler l'évolution thermique des huiles, nous avons réalisé une

  7. A Mechanistic Model for Predicting and Optimising Oil-Sand Flow in Horizontal Wells Modèle mécanistique pour la prévision et l’optimisation des écoulements huile-sable dans des puits horizontaux

    Directory of Open Access Journals (Sweden)

    Bello O.

    2011-05-01

    Full Text Available Smart well completion technology for sand management is being used more and more in the petroleum industry to increase productivity and cumulative hydrocarbon production over that of classical sand control techniques. While an understanding of the geomechanics aspects of sand production has begun to emerge, predicting and optimising two-phase oil-sand flow performance characteristics in horizontal wellbores remains a challenge. This theoretical study analysed two-phase, oil-sand suspended flow in a horizontal well by developing a new phenomenological model to predict lift velocity and pressure drop profiles, which are key parameters for designing optimal deployment of horizontal wells in an unconsolidated reservoir. Computations of average pressure drop for two-phase oil-sand flow in a horizontal well are in reasonable agreement with values predicted by a previous model for a relatively wide range of operating conditions. However, the new model eliminates the need for empiricism in predicting the wellbore hydraulics for oil-sand multiphase flow in horizontal wells and is applicable to different wellbore geometries. The proposed computational methodology has been applied to a hypothetical case study to demonstrate its field applicability. Les techniques de complétions intelligentes de puits avec gestion de venues de sable sont de plus en plus utilisées dans l’industrie pétrolière. Comparées aux techniques classiques de gestion de venues de sable, elles améliorent la productivité et la production cumulée d’hydrocarbures. Cependant, alors que les aspects géomécaniques de la production de sable sont de mieux en mieux appréhendés, la prévision et l’optimisation des écoulements diphasiques huile-sable dans les puits horizontaux posent toujours problème. Dans cette étude, une analyse théorique de l’écoulement d’un mélange huile-sable en suspension dans un puits horizontal a été effectuée. Pour ce faire, des modèles ph

  8. Review of progress in modelling for the assessment of the operating life of a nuclear power plant; Panorama des progres de la modelisation au service de la duree de vie des centrales

    Energy Technology Data Exchange (ETDEWEB)

    Monnier, B. [Electricite de France (EDF/RD), 78 - Chatou (France); Gilles, Ph. [FRAMATOME ANP, 92 - Paris-La-Defence (France); Chauliac, Ch. [CEA Saclay, Dir. de l' Energie Nucleaire DEN/DSOE, 91 - Gif sur Yvette (France)

    2004-07-01

    This article reviews the contributions of simulation and modelling to the assessment of the service life of a nuclear power plant. 4 aspects are considered. The first aspect concerns the operating life of the reactor vessel, in order to evaluate its aging a series of more or less intertwined modelling is necessary, they concern thermal-hydraulic transients, neutron fluences, damages due to irradiation and thermal-mechanical behaviour. The second aspect is the use of simulation to optimize non-destructive testing (NDT) particularly to assess the performances and limits of NDT methods in order to assure safety in any situation. The third aspect concerns the simulation of welding in order to assess the risk of defect occurrence, the pile-up of residual stresses and the feasibility of a complex welding. The last aspect is a global simulation of a nuclear unit as a whole involving its main components such as vessel, pumps, steam generators, turbine...; their maintenance, their failure risks in order to define indicator parameters that are relevant to the real state of the plant. (A.C.)

  9. Chirurgie des grassmanniennes

    CERN Document Server

    Lafforgue, Laurent

    2003-01-01

    Les compactifications diverses de variétés de modules sont un thème important et récurrent des mathématiques modernes, et elles connaissent un grand nombre d'applications. Ce livre traite le cas de cellules de Schubert minces, qui sont de sous-variétés naturelles de grassmanniennes. L'auteur a été amené à traiter ces questions par un cas particulier lié à ses travaux sur le programme de Langlands. Dans cette monographie, il en développe une théorie plus systématique, présentant le fortes similarités avec celle des modules du courbes stables. The various compactifications of moduli spaces are an important recurrent theme of modern mathematics, and they have a large number of applications. This book treats the case of thin Schubert varieties, which are natural subvarieties of Grassmannians. The author was led to these questions by a particular case linked to his work on the Langlands program. In this monograph, he develops the theory in a more systematic way, which exhibits strong similarities...

  10. Mécanique des sols et des roches

    CERN Document Server

    Vullier, Laurent; Zhao, Jian

    2016-01-01

    La mécanique des sols et la mécanique des roches sont des disciplines généralement traitées séparément dans la littérature. Pour la première fois, un traité réunit ces deux spécialités, en intégrant également les connaissances en lien avec les écoulements souterrains et les transferts thermiques. A la fois théorique et pratique, cet ouvrage propose tout d'abord une description détaillée de la nature et de la composition des sols et des roches, puis s'attache à la modélisation de problèmes aux conditions limites et présente les essais permettant de caractériser les sols et les roches, tant d'un point de vue mécanique qu'hydraulique et thermique. La problématique des sols non saturés et des écoulements multiphasiques est également abordée. Une attention particulière est portée aux lois de comportement mécanique et à la détermination de leurs paramètres par des essais in situ et en laboratoire, et l'ouvrage offre également une présentation détaillée des systèmes de classi...

  11. Perception des producteurs sur l'utilisation des déjections de ...

    African Journals Online (AJOL)

    Objectif: L'étude vise à analyser la perception des producteurs sur la contribution des chenilles dans la gestion de la fertilité des sols et dans la production des ... Les producteurs enquêtés ont par ailleurs, identifié les facteurs anthropiques, climatiques et édaphiques comme les facteurs pouvant influencer la dynamique des ...

  12. Modelling of the hydrogen effects on the morphogenesis of hydrogenated silicon nano-structures in a plasma reactor; Modelisation des effets de l'hydrogene sur la morphogenese des nanostructures de silicium hydrogene dans un reacteur plasma

    Energy Technology Data Exchange (ETDEWEB)

    Brulin, Q

    2006-01-15

    This work pursues the goal of understanding mechanisms related to the morphogenesis of hydrogenated silicon nano-structures in a plasma reactor through modeling techniques. Current technologies are first reviewed with an aim to understand the purpose behind their development. Then follows a summary of the possible studies which are useful in this particular context. The various techniques which make it possible to simulate the trajectories of atoms by molecular dynamics are discussed. The quantum methods of calculation of the interaction potential between chemical species are then developed, reaching the conclusion that only semi-empirical quantum methods are sufficiently fast to be able to implement an algorithm of quantum molecular dynamics on a reasonable timescale. From the tools introduced, a reflection on the nature of molecular metastable energetic states is presented for the theoretical case of the self-organized growth of a linear chain of atoms. This model - which consists of propagating the growth of a chain by the successive addition of the atom which least increases the electronic energy of the chain - shows that the Fermi level is a parameter essential to self organization during growth. This model also shows that the structure formed is not necessarily a total minimum energy structure. From all these numerical tools, the molecular growth of clusters can be simulated by using parameters from magnetohydrodynamic calculation results of plasma reactor modeling (concentrations of the species, interval between chemical reactions, energy of impact of the reagents...). The formation of silicon-hydrogen clusters is thus simulated by the successive capture of silane molecules. The structures formed in simulation at the operating temperatures of the plasma reactor predict the formation of spherical clusters constituting an amorphous silicon core covered by hydrogen. These structures are thus not in a state of minimum energy, contrary to certain experimental

  13. La Flore Des Adventices Des Cultures Cotonnieres De La Region ...

    African Journals Online (AJOL)

    A partir de relevés itinérants réalisés dans des cultures cotonnières de la région du Worodougou, en Côte d\\'Ivoire, précisement à Mankono, Dianra et Séguéla, 230 espèces d\\'adventices ont été recensées. Dans chacune des trois localités inventoriées, il apparaît que les familles des Poaceae, Fabaceae et Asteraceae ...

  14. Evaluation de la gestion des dechets issus des activites de ...

    African Journals Online (AJOL)

    Le moyen d'élimination des déchets utilisé est l'incinération. Tous les agents impliqués dans la vaccination ont une connaissance des risques de contamination liés aux déchets vaccinaux. La gestion des déchets reste un système global dont tous les aspects méritent d'être considérés. Chaque étape de l'élimination est ...

  15. Characterization and modelling of fluid flows in fissured and fractured media. relation with hydrothermal alterations and paleo-stress quantification; Caracterisation et modelisation des ecoulements fluides en milieu fissure. relation avec les alterations hydrothermales et quantification des paleocontraintes

    Energy Technology Data Exchange (ETDEWEB)

    Sausse, J.

    1998-10-15

    the modelization of the space-time evolution of the Brezouard granite crack permeability during fluid-rock interactions. The two used permeability models (geometrical or statistical) remain very dependent on the definition of the characteristic opening of fracture or fissure. Real fractures in a rocky mass are characterised by non parallel, flat and thus overlapped walls. The study of these natural fracture surfaces at micro and macroscopic scale is completed by a theoretical modelization of their hydro-mechanical behaviour. This work indicates the influence of the surface roughness on the fluid flow as well as the propagation of the alteration. These fractures were formed and percolated under a particular tectonic regime that controls their orientation. Numerous quartz veins in the Soultz granite are opened and sealed during the Oligocene extension. The characteristic fluid pressure of these opening - sealing stages are quantified thanks to fluid inclusion studies. These inclusions are located in secondary quartz which seal the veins. A new method of paleo-stress quantification is proposed, based on the knowledge of this fluid pressure. It takes i) the geometrical distribution of the vein poles, ii) some empirical considerations of rupture criteria, and iii) the fluid pressures into account. (author)

  16. Radiative transfer modelling in combusting systems using discrete ordinates method on three-dimensional unstructured grids; Modelisation des transferts radiatifs en combustion par methode aux ordonnees discretes sur des maillages non structures tridimensionnels

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, D.

    2004-04-01

    The prediction of pollutant species such as soots and NO{sub x} emissions and lifetime of the walls in a combustion chamber is strongly dependant on heat transfer by radiation at high temperatures. This work deals with the development of a code based on the Discrete Ordinates Method (DOM) aiming at providing radiative source terms and wall fluxes with a good compromise between cpu time and accuracy. Radiative heat transfers are calculated using the unstructured grids defined by the Computational Fluid Dynamics (CFD) codes. The spectral properties of the combustion gases are taken into account by a statistical narrow bands correlated-k model (SNB-ck). Various types of angular quadrature are tested and three different spatial differencing schemes were integrated and compared. The validation tests show the limit at strong optical thicknesses of the finite volume approximation used the Discrete Ordinates Method. The first calculations performed on LES solutions are presented, it provides instantaneous radiative source terms and wall heat fluxes. Those results represent a first step towards radiation/combustion coupling. (author)

  17. Modeling of polarization phenomena due to RF sheaths and electron beams in magnetized plasma; Modelisation de phenomenes de polarisation par des gaines rf et des faisceaux electroniques dans un plasma magnetise

    Energy Technology Data Exchange (ETDEWEB)

    Faudot, E

    2005-07-01

    This work investigates the problematic of hot spots induced by accelerated particle fluxes in tokamaks. It is shown that the polarization due to sheaths in the edge plasma in which an electron beam at a high level of energy is injected, can reach several hundreds volts and thus extend the deposition area. The notion of obstructed sheath is introduced and explains the acceleration of energy deposition by the decreasing of the sheath potential. Then, a 2-dimensional fluid modeling of flux tubes in front of ICRF antennae allows us to calculate the rectified potentials taking into account RF polarization currents transverse to magnetic field lines. The 2-dimensional fluid code designed validates the analytical results which show that the DC rectified potential is 50% greater with polarization currents than without. Finally, the simultaneous application of an electron beam and a RF potential reveals that the potentials due to each phenomenon are additives when RF potential is much greater than beam polarization. The density depletion of polarized flux tubes in 2-dimensional PIC (particles in cells) simulations is characterized but not yet explained. (author)

  18. Validation of Rheological Models of Typical Structures : an Attempt to Work Out an Insurance-Quality Procedure Validation des modèles rhéologiques sur ouvrages types : une tentative de démarche d'assurance-qualité

    Directory of Open Access Journals (Sweden)

    Meimon Y.

    2006-11-01

    Full Text Available For four years now, a validation of models for typical structuresgroup has been constituted inside the GRECO group on Rheology of Geomaterialssponsored by CNRS (French National Research Council. It has been working on the development of a methodology for validating rheological models of geomaterials. The aim was to reduce the gap between the theory and the practice of geomechanical computing. In a first step, the group work has been applied to shallow fondations. A complete validation process, which can be understood as an insurance-quality procedure, has been worked out, ranging from validation on the basis of homogeneous laboratory tests to validation based on boundary problems. Partial computerization of validation has been achieved with the help of a suitable software environment. A databank of laboratory and centrifuge tests has been created. An attempt has been made to define qualification criteria for models. Numerous rheological models have been applied, including some relatively sophisticated ones. This work has reached the point where the generalization of the procedure can been foreseen within the wider setting of the validation of geomechanical programs. Les travaux de validation Durant quatre ans (1986-1989, le groupe Validation des Modèles sur Ouvrages Typesdu GRECO CNRS Rhéologie des Géomatériaux , s'est efforcé de développer une méthodologie de validation des modèles rhéologiques de géomatériaux dans le but de réduire le décalage entre théorie et pratique des calculs en géomécanique, en appuyant son travail sur l'ouvrage type fondation superficielleet sur une collaboration étroite entre des équipes universitaires et des centres techniques et industriels. Les principaux travaux du groupe, constitué, d'une part de laboratoires universitaires français ou européen (École Centrale de Lyon (ECL, École Centrale de Paris (ECP, École Nationale des Travaux Publics de l'État (ENTPE, Institut de Mécanique de

  19. Evaluation des activites antihyperglycemiantes d'extraits aqueux de ...

    African Journals Online (AJOL)

    écorce de Casuarina equisetifolia révèle la présence des alcaloïdes, des tanins, des flavonoïdes, des leucoanthocyanes, des dérivés anthracéniques, des coumarines et des composés réducteurs, composés aux propriétés médicales multiples, ...

  20. Engagements contractuels et performances des organisations de ...

    African Journals Online (AJOL)

    amélioration des performances des organisations des producteurs (OP) à l'Ouest Cameroun. Il est basé sur des enquêtes par questionnaires auprès des délégués de 33 OP de maïs bénéficiaires de l'encadrement du Programme d'Amélioration de la ...

  1. Médecine des voyages

    Science.gov (United States)

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  2. Influence des facteurs agro-écologiques et des herbicides sur le ...

    African Journals Online (AJOL)

    Influence des facteurs agro-écologiques et des herbicides sur le rendement et les caractéristiques technologiques des grains et farines de blés tendres ( Triticum aestivum L.) et durs ( Triticum durum Desf.)

  3. Evaluation des pratiques de gestion des adventices en riziculture ...

    African Journals Online (AJOL)

    Le riz est l'aliment principal pour la quasi-totalité des populations vivant en Côte d'Ivoire. Cependant, les adventices sont considérées comme la contrainte biologique la plus importante faisant obstacle à la production rizicole. L'objectif de cette étude menée en 2015 était d'évaluer différentes techniques de gestion des ...

  4. Des agriculteurs trouvent des moyens d'exploiter les avantages ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    19 sept. 2013 ... Le tout dernier prototype sera adapté en vue de son utilisation dans les collectivités et les villages. On continuera d'y apporter des améliorations pour lui permettre de moudre d'autres mils (le pied de coq et l'herbe à épée ou kodo). Des chercheurs de la Tamil Nadu Agricultural University s'emploient aussi ...

  5. Modernisation des marchés agroalimentaires - inclusion des petits ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les marchés agroalimentaires connaissent de rapides changements dans les pays en développement et les pays en transition. Sous l'influence de la libéralisation du commerce et des nouvelles technologies de transformation des aliments et de commerce de détail, les marchés agroalimentaires évoluent vers une plus ...

  6. Therapie des Harnwegsinfekts

    Directory of Open Access Journals (Sweden)

    Stoiser B

    2010-01-01

    Full Text Available Harnwegsinfektionen gehören zu den häufigsten entzündlichen Erkrankungen im niedergelassenen Bereich. Eine intelligente Therapiestrategie stellt damit nicht nur eine klinische Herausforderung dar, sondern ermöglicht rasche Heilung, Vermeidung von Resistenzbildungen sowie oft unnötiger, teurer diagnostischer Schritte. Der erste entscheidende Schritt ist die genaue Klassifizierung des Harnweginfektes – asymptomatische Bakteriurie bis zur komplizierten Pyelonephritis. Hier entscheiden sich bereits Aggressivität der Behandlung sowie diagnostischer Aufwand. Für die Entwicklung einer empirischen antimikrobiellen Therapie ist die Kenntnis der häufigsten Erreger sowie lokaler Resistenzmuster wichtig. Bei gezieltem Vorgehen können die meisten Harnwegsinfekte ohne erhöhten diagnostischen Aufwand therapiert werden.

  7. Code des baux 2018

    CERN Document Server

    Vial-Pedroletti, Béatrice; Kendérian, Fabien; Chavance, Emmanuelle; Coutan-Lapalus, Christelle

    2017-01-01

    Le code des baux 2018 vous offre un contenu extrêmement pratique, fiable et à jour au 1er août 2017. Cette 16e édition intègre notamment : le décret du 27 juillet 2017 relatif à l’évolution de certains loyers dans le cadre d’une nouvelle location ou d’un renouvellement de bail, pris en application de l’article 18 de la loi n° 89-462 du 6 juillet 1989 ; la loi du 27 janvier 2017 relative à l’égalité et à la citoyenneté ; la loi du 9 décembre 2016 relative à la transparence, à la lutte contre la corruption et à la modernisation de la vie économique ; la loi du 18 novembre 2016 de modernisation de la justice du xxie siècle

  8. Les derives conscients des mecanismes de defense au questionnaire de Bond (DSQ 40) : stabilite ou variabilite entre une situation non anxiogene et une situation anxiogene

    OpenAIRE

    2010-01-01

    Resume L?objectif de cette recherche est de tester la stabilite ou la variabilite des derives conscients des mecanismes de defense evalues a l?aide du questionnaire de Bond (DSQ 40) dans deux situations differemment anxiogenes afin de les integrer dans le modele transactionnel du stress de Lazarus et Folkman. Pour tester l?instabilite intersituationnelle des derives conscients des mecanismes de defense, une population de 161 etudiantes a complete le questionnaire de Bond (DSQ 40) e...

  9. Prise en compte du gonflement des terrains dans le dimensionnement des revêtements des tunnels

    OpenAIRE

    Bultel, Frédéric

    2001-01-01

    Travail préparé au Laboratoire Central des Ponts et Chaussées (LCPC-Paris) dans le cadre d'une convention CIFRE avec la société Scetauroute,Composition du jury : MM. R. KASTNER professeur à l'Institut National des Sciences Appliquées de Lyon (rapporteur),I. SHAHROUR professeur à l'Ecole Universitaire Des Ingénieurs de Lille (rapporteur), P. EGGER professeur à l'Ecole Polytechnique Fédérale de Lausanne (Examinateur), B. GAUDIN expert géotechnique à Scetauroute-DTTS (Examinateur), J.P. MAGNAN D...

  10. Digitalisierung des Kulturellen Erbes (Europas)

    NARCIS (Netherlands)

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland.

  11. Physically founded modelling of transient heat transfer in diesel engine combustion chambers with application of 3D-CFD calculations. Final report; Physikalisch fundierte Modellierung des instationaeren Wandwaermeueberganges im Brennraum von Dieselmotoren mit Applikation an 3D-CFD-Rechnungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Merker, G.P.; Lettmann, H.

    2003-05-01

    A phenomenological wall heat transfer model was developed for diesel engines, enhanced for application of the 3D-CFC code KIVA-3V, and implemented in the code. Further, the heat flow was measurement near the cylinder head, bushel and piston of a DI one-cylinder experimental diesel engine. The influence of soot radiation and convective heat transfer on the wall are modelled separately. The insulating effect of soot deposits on the walls during engine operation is taken into acount as well. The multizone model and the 3D model are in good agreement with the models by Han and Reitz (1997) and with experimental findings. The spatial resolution of heat flow at the wall further shows that both the radiative and convective heat flow are strongly locally dependent. The model presents a physically correct description of the heat flow at the wall of a diesel engine combustion chamber. [German] Im Rahmen des gesamten Forschungsvorhabens wurden ein phaenomenologisches Wandwaermeuebergangsmodell fuer Dieselmotoren entwickelt, dieses wurde fuer die Anwendung in den 3D-CFD-Code KIVA-3V erweitert und in den Code implementiert. Zusaetzlich sind Waermestrommessungen im Brennraum an Zylinderkopf, Laufbuchse und Kolben durchgefuehrt worden. Dafuer stand ein direkteinspritzender Einzylinder-Versuchsdieselmotor zur Verfuegung. Das im Rahmen dieses Vorhabens entwickelte Waermeuebergangsmodell bildet den Einfluss der Russstrahlung und des konvektiven Wandwaermeueberganges separat ab. Die isolierende Wirkung von Russwandablagerungen waehrend des gefeuerten Motorbetriebes wird dabei ebenfalls beruecksichtigt. Das Mehrzonenmodell sowie das 3D-Modell zeigen sehr gute Uebereinstimmungen des raeumlich gemittelten Wandwaermestroms mit den Modellen von Han und Reitz (1997) und den experimentellen Ergebnissen. Die raeumliche Aufloesung der Wandwaermestroeme zeigt weiter, dass auf der Brennraumoberflaeche die Strahlungswaermestroeme und die konvektiven Waermestroeme stark ortsabhaengig sind. Damit

  12. La cogestion des Ressources naturelles

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le Liban — les conflits sur les ressources et la modification des moyens de subsistance à Arsaal . 71. Chapitre ..... Ainsi, un seul arbre d'une forêt peut fournir des fruits, du bois de chauffage, du fourrage et de l'ombrage; constituer un stabilisateur du sol et un habitat faunique et représenter un lien avec l'identité ancestrale.

  13. CONTRAINTES INSTITUTIONNELLES ET LABELLISATION DES ...

    African Journals Online (AJOL)

    de labellisation des produits algériens (particulièrement le vin et les dattes) par le biais des indications géographiques et les contraintes institutionnels et territoriales qui contrarient ce processus. Le contexte algérien, très marqué par une économie mono-ex- portatrice et très dépendante à l'égard d'un seul type de produit, ...

  14. Modelisation des emissions de particules microniques et nanometriques en usinage

    Science.gov (United States)

    Khettabi, Riad

    La mise en forme des pieces par usinage emet des particules, de tailles microscopiques et nanometriques, qui peuvent etre dangereuses pour la sante. Le but de ce travail est d'etudier les emissions de ces particules pour fins de prevention et reduction a la source. L'approche retenue est experimentale et theorique, aux deux echelles microscopique et macroscopique. Le travail commence par des essais permettant de determiner les influences du materiau, de l'outil et des parametres d'usinage sur les emissions de particules. E nsuite un nouveau parametre caracterisant les emissions, nomme Dust unit , est developpe et un modele predictif est propose. Ce modele est base sur une nouvelle theorie hybride qui integre les approches energetiques, tribologiques et deformation plastique, et inclut la geometrie de l'outil, les proprietes du materiau, les conditions de coupe et la segmentation des copeaux. Il ete valide au tournage sur quatre materiaux: A16061-T6, AISI1018, AISI4140 et fonte grise.

  15. Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

    African Journals Online (AJOL)

    SARAH

    30 sept. 2017 ... sont le barrage, les puits à faible profondeur (1 à 2 m) et les tranchées creusées dans la cuvette par les maraîchers. 22 % des producteurs utilisent l'eau du barrage directement, 60 % l'eau des puits (figure 2) uniquement et 18 % utilisent les deux types de ressources (figure 3). Toutes les cultures en saison ...

  16. Étude des caractéristiques des peuplements et des noix de Cocos ...

    African Journals Online (AJOL)

    Cocos nucifera est l'un des arbres cultivés le plus répandu. Il se propage par graine avec un long cycle biologique. Cette étude qui avait pour objectif de caractériser les populations naturelles de cocotiers des Niayes (Sénégal), notamment leur structure et leur fruit, a montré que les arbres sont âgés et leur régénération ...

  17. L'accumulation des métaux lourds au niveau des cultures : Cas des ...

    African Journals Online (AJOL)

    Le Bassin de Sebou présente une importance socio-économique pour le Maroc. En effet, il est sujet de diverses utilisations ; eau potable, eau d'irrigation et eau industrielle. Toutefois, ce bassin subit des pressions multiples, notamment par la pollution métallique. Considérant le risque de bioaccumulation des métaux par ...

  18. Minimisation des inductances propres des condensateurs à film métallisé

    Science.gov (United States)

    Joubert, Ch.; Rojat, G.; Béroual, A.

    1995-07-01

    In this article, we examine the different factors responsible for the equivalent series inductance in metallized capacitors and we propose structures for capacitors that reduce this inductance. After recalling the structure of metallized capacitors we compare, by experimental measurements, the inductance due to the winding and that one added by the connections. The latter can become preponderant. In order to explain the experimental evolution of the winding impedance vs. frequency, we describe an analytical model which gives the current density in the winding and its impedance. This model enables us to determine the self resonant frequency for different types of capacitors. From where, we can infer the influence of the height of capacitors and their internal and external radius upon performances, It appears that to reduce the equivalent series inductance, it is better to use flat windings and annular windings. Dans cet article nous examinons les différents facteurs responsables de l'inductance équivalente série dans les condensateurs à film métallisé et proposons des géométries de condensateurs qui réduisent cette inductance. Après avoir rappelé la structure des condensateurs à film métallisé, nous comparons, par des mesures expérimentales, l'inductance due au bobinage et l'inductance ajoutée par les connexions. Cette dernière peut devenir prépondérante. Afin d'expliquer l'évolution de l'impédance du bobinage en fonction de la fréquence, nous décrivons un modèle analytique qui donne la densité du courant dans le bobinage et l'impédance de ce dernier. En outre, ce modèle permet de déterminer la fréquence de résonance série de divers types de condensateurs ce qui permet de déduire l'influence de la hauteur des condensateurs et de leurs rayons interne et externe sur les performances. Il apparaît ainsi que, pour diminuer l'inductance équivalente série, il vaut mieux employer des bobinages plats et des bobinages annulaires.

  19. Poissons Characoïdes des Guyanes. I. Généralités. II. Famille des Serrasalmidae

    NARCIS (Netherlands)

    Géry, J.

    1972-01-01

    TABLE DES MATIÈ RES ENGLISH PREFACE AND SUMMARY......... 5 AVANT-PROPOS................. 8 RESUME ................... 9 PREMIERE PARTIE : GENERALITES SUR LES GUYANES ET LES POISSONS CHARACOÏDES................. 12 Chapitre 1. Introduction 1-1. Historique.................. 12 1- 2. Sources et

  20. Onlinespieler abseits des Mainstreams

    Directory of Open Access Journals (Sweden)

    Harald Baumgartlinger

    2012-12-01

    Full Text Available MMO(RPGs „Massively Multiplayer Online (Role-Playing Games“ nehmen einen Sonderstatus unter den Onlinespielen ein, welcher durch den wachsenden wirtschaftlichen Erfolg, insbesondere durch den „breakthrough hit“ (Duchenaut et al. 2006: 407 World of Warcraft (WoW, auch an Bedeutung für die Medien- und Kommunikationswissenschaft gewinnt (vgl. Inderst 2009: 15; vgl. Seifert/Jöckel 2008: 297. Der Primus des Genres, WoW, repräsentiert gemeinsam mit einigen nahezu identen Titeln insgesamt 85 Prozent der gespielten MMOGs (vgl. Williams et al. 2008: 999. Daher befasst sich auch die Mehrheit der vorliegenden Studien mit eben diesen Spielen. Neue Formen von MMO(Gs können jedoch zu ebenso neuartigen Spielerfahrungen führen und damit unterschiedliche Nutzungsmotive befriedigen (vgl. Seifert/Jöckel 2008: 309 und folglich zu einem gänzlich anderen Spielerleben führen. Während im Mainstream die kooperativen Spielerbeziehungen überwiegen, dominiert in Darkfall Online der soziale Wettbewerb. Der von Williams et al. 2008 verwendete Fragebogen diente als Rohling für die Kreation eines für die speziellen Anforderungen adaptierten Erhebungstools zur Erforschung der Spielertypologie und der Motive der Darkfall-Online-SpielerInnen. Die in der Onlinebefragung (N = 506 gesammelten Daten belegen, dass sich sowohl die Spielerdemographie, als auch die Motive der Spieler von den Mainstream MMOs unterscheiden. Zudem konnten realweltliche Eigenschaften der Spieler als signifikante Einflussfaktoren für die Spielzuwendung identifiziert werden.

  1. Terre des hommes

    CERN Multimedia

    Staff Association

    2012-01-01

    Transformez votre téléphone portable en geste de solidarité ! Collecte du 12 au 23 novembre 2012   Faites un geste simple et utile en déposant vos téléphones portables inutilisés dans les urnes installées dans les trois restaurants du CERN. En Suisse, une personne change tous les 12 à 18 mois de téléphone portable. La plupart de nos vieux appareils sont simplement laissés à l’abandon avec comme seule fonction de parer une éventuelle panne à venir. On  estime ainsi que 8 millions de portables sont inutilisés, alors qu'entre 30 et 50% peuvent être réutilisés. L'action Solidarcomm leur offre une deuxième vie ! Terre des Hommes Suisse, dans le cadre de la campagne Solidarcomm, collecte et valorise vos téléphones inutilis&...

  2. Modélisation du comportement et des couplages HMC des milieux poreux

    OpenAIRE

    Hoang , Ha

    2012-01-01

    Modelling of the behavior and the couplings HMC of the porous circles; La modélisation du comportement hydromécanique chimique des milieux poreux saturés et non saturés est abordée au niveau microscopique et mésoscopique. Au niveau microscopique la modélisation des écoulements diphasiques est basée sur une représentation du réseau poral comme un ensemble de tubes dont les orientations et les rayons sont choisis sur un principe d’équivalence avec les pores. L’algorithme régissant la génération...

  3. Recoupement des politiques: renforcer les initiatives de reddition de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Au cours des dernières années, les acquisitions massives (achats, locations ou autres arrangements) de terres agricoles dans les pays en développement par des particuliers, des entreprises et des gouvernements étrangers ont eu des effets économiques positifs tout comme des effets négatifs sur les moyens de ...

  4. 107 Etude des facteurs de variation des prix d'intérêt des matières ...

    African Journals Online (AJOL)

    DELL

    Imen BELHADJ SLIMEN et Taha NAJAR. Etude des facteurs de variation des prix d'intérêt des matières premières de substitution utilisées dans les aliments concentrés des animaux d'élevage. Imen BELHADJ SLIMEN1,2* et Taha NAJAR1,2. 1Institut National Agronomique de Tunisie, Département Ressources Animales, ...

  5. Risks of a coastal region in case of climate changes: economic evolution and spatial modelling of the damage potential in the lower Weser region; Risiko einer Kuestenregion bei Klimaaenderung: Oekonomische Bewertung und raeumliche Modellierung des Schadenspotentials in der Unterweserregion

    Energy Technology Data Exchange (ETDEWEB)

    Kiese, M.; Leineweber, B.

    2001-07-01

    An accelerated increase of the sea-level causes the coastal protection to change from an absolute necessity (coastal protection at any price) to a decision problem due to empty public cash boxes. In order to guarantee an efficient distribution of the scarce financial means the most urgent coastal protection investments must be assessed by means of a cost-benefit analysis. The benefit of a coastal protection measure corresponds to the avoided damage in case of failure (''if the flood comes''). Taking into account equal conditions extension measures must be carried out where the damage potential to the hinterland is the highest. The part of the project ''Risks of a coastal region in case of climate changes: Economic evaluation and spatial modelling of the damage potential in the Lower Weser region Bremerhaven - Butjadingen - Land Wursten'' worked on by the Department of Economic Geography of the Geographic Institute of the University Hanover, is supposed to assess the ''protected values'' located behind the dike, evaluate the monetary value and develop a spatial model. The obtained protected values, which are related with damage functions, indicate the damage potential that would have to be expected in case of flooding. The results of this project are incorporated in the research project ''Risks of a coastal region in case of climate changes'' that is carried out by the Franzius Institute for water construction and coastal engineering in cooperation with the Department of Economic Geography. (orig.) [German] Ein beschleunigter Meeresspiegelanstieg macht den Kuestenschutz angesichts leerer oeffentlicher Kassen zunehmend von einer Unbedingtheit (Kuestenschutz um jeden Preis) zu einem Entscheidungsproblem. Um eine effiziente Allokation der knappen Mittel zu gewaehrleisten, sind die vordringlichsten Kuestenschutzinvestitionen mit Hilfe von Kosten-Nutzen-Analysen zu ermitteln. Dabei entspricht

  6. Die Rolle des Gerichtsdolmetschers - Experte oder notwendiges Übel?

    DEFF Research Database (Denmark)

    Christensen, Tina Paulsen

    2012-01-01

    vorstelle, ist es zu untersuchen, welche normative Rolle die dänischen Richter Gerichtsdolmetschern zumessen. Mein Beitrag stellt die Ergebnisse einer online-Befragung unter sämtlichen dänischen Richtern vor. Die Richter wurden gebeteten ihre Erwartungen an und erlebten Probleme mit Gerichtsdolmetschern...... mittels der Storytelling-Methode zu erläutern. In meinem Beitrag unterscheide und analysiere ich die qualitativen Kommentare der Richter unter Heranziehung des Modells von Niska (2002) über die Rollen des Kommunaldolmetschers als entweder conduit, clarifier, culture broker und advocate, um so zu ermitteln...... Konzeption erfolgreicher Maßnahmen dienen, die eine effektive mehrsprachige Interaktion unterstützen....

  7. Gyrodactylidae et Gyrodactylose des Salmonidae

    Directory of Open Access Journals (Sweden)

    MALMBERG G.

    1993-01-01

    Full Text Available Vingt et une espèces de Gyrodactylus de Salmonidae arrangées en six groupes sont présentées. Les observations concernant ces espèces dans les milieux naturels et en pisciculture sont résumées. Sur la base de données générales relatives aux espèces de Gyrodactylus en milieu naturel en Scandinavie et Baltique, les observations biologiques, écologiques et comportementales de G. salaris Malmberg, 1957 et G. derjavini MALMBERG et MALMBERG (1987 des salmonidae sauvages des rivières norvégiennes et suédoises sont présentées. La viviparité unique, la reproduction asexuée et sexuée et le pouvoir de reproduction chez les Gyrodactylus sont développés. La Gyrodactylose à G. salaris est abordée en milieu naturel, dans les rivières norvégiennes et en pisciculture, en Suède et au Danemark. L'étude ultrastructurale des blessures causées par G. salaris ainsi que les résultats expérimentaux sur les espèces norvégiennes et canadiennes sont présentés. La distribution géographique naturelle des Salmonidae, les modifications liées à l'homme et à l'activité économique ainsi que les Salmonidae élevés sont revus. La présence de six groupes d'espèces de Gyrodactylus en Amérique du Nord et Eurasie est discutée en fonction de la distribution géographique des espèces hôtes. Il est souligné qu'une propagation intercontinentale des espèces de Gyrodactylus de Salmonidae a dû être impossible à cause de leur origine limnique d'une part et de la salinité élevée des océans atlantique et pacifique d'autre part. Les exigences micro et macro environnementales des espèces sont discutées dans les conditions naturelles et les variations saisonnières, préférendums et tolérances du parasitisme sont signalés. L'effet des conditions de pisciculture sur les espèces de Gyrocactylus sont discutées : la capacité reproductrice et de propagation ainsi que la spécificité — stricte dans la nature — peuvent être influenc

  8. Promouvoir l'inclusion économique des jeunes et des femmes par l ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    entrepreneuriat à Madagascar. Le projet vise à promouvoir l'entrepreneuriat des femmes et des jeunes à Madagascar à travers le renforcement des capacités locales de recherche et des analyses pertinentes et utiles. En particulier les objectifs sont de ...

  9. Contamination des moules ( Mytilus galloprovincialis ) des côtes de ...

    African Journals Online (AJOL)

    Dans ce travail, nous avons etudie la contamination par les Hydrocarbures Aromatiques Polycycliques des moules recoltees au niveau des cotes de la region de Dakar. Les sites ont ete choisis en fonction des activites qui y sont developpees. Lfextraction des HAPs a ete faite au moyen dfun extracteur Soxhlet avec un ...

  10. Taux des lipides et des protéines et composition en acides gras du ...

    African Journals Online (AJOL)

    Taux des lipides et des protéines et composition en acides gras du tissu comestible des crustacés et des mollusques pêchés en Algérie : Effet du halofénozide (RH-0345) sur la composition en acides gras de Penaeus kerathurus (Crustacé, Décapode).

  11. Étude des impacts écologiques du dynamisme spatio-temporel des ...

    African Journals Online (AJOL)

    changement, (iv) élaborer une prospective des changements en 2050 et (v) évaluer les impacts du changement. Le change- ment des habitats naturels s'est déroulé au cours des temps mais il n'a ... assesses the impacts of habitat change on the resident glob- ... La gestion des changements, qui se manifestent presque.

  12. Model based simulation of alternative transmission concepts in early stages of product development process; Einsatz von Simulationsmodellen zur Beurteilung von alternativen Getriebekonzepten in fruehen Phasen des Produktentstehungsprozesses

    Energy Technology Data Exchange (ETDEWEB)

    Albers, A.; Ott, S.; Seifermann, A. [Karlsruhe Univ. (Germany). IPEK - Inst. fuer Produktentwicklung

    2006-07-01

    The contribution describes a method for assessing the new transmission concepts and investigate their advantages in alternative powertrain systems. Simulation models of different powertrains were used in order to make the different concepts comparable in an early stage of the product developmentprocess. Further, it is shown how the Contact and Channel Model (C and CM) can be used for modelling individual transmission concepts. These models can help to identify and assess interdependences between part systems and components. (orig.)

  13. Ostéosynthèse des fractures des métacarpiens et des phalanges de ...

    African Journals Online (AJOL)

    Ostéosynthèse des fractures des métacarpiens et des phalanges de la main par mini plaque: à propos de 12 cas. Erraji Moncef, Derfoufi Abdelhafid, Kharraji Abdessamad, Agoumi Omar, Abdeljaouad Najib, Daoudi Abdelkrim, Yacoubi Hicham ...

  14. Geochemical and numerical modelling of interactions between solid solutions and an aqueous solution. Extension of a reactive transport computer code called Archimede and application to reservoirs diagenesis; Modelisation geochimique et numerique des interactions entre des solutions solides et une solution aqueuse: extension du logiciel de reaction-transport archimede et application a la diagenese des reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Nourtier-Mazauric, E.

    2003-03-15

    This thesis presents a thermodynamic and kinetic model of interactions between a fluid and ideal solid solutions represented by several end-members. The reaction between a solid solution and the aqueous solution results from the competition between the stoichiometric dissolution of the initial solid solution and the co-precipitation of the least soluble solid solution in the fluid at considered time. This model was implemented in ARCHIMEDE, a computer code of reactive transport in porous media, then applied to various examples. In the case of binary solid solutions, a graphical method allowed to determine the compositions of the precipitating solid solutions, with the aid of the end-member chemical potentials. The obtained program could be used to notably model the diagenesis of clayey or carbonated oil reservoirs, or the ground pollutant dispersion. (author)

  15. La convergence des rôles respectifs des relationnistes et des journalistes influence-t-elle la perception qu'ils ont les uns des autres?

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    la convergence des rôles respectifs des praticiens des relations publiques et des journalistes a un effet favorable sur la perception qu’ils ont les uns des autres. L’effet est plus marqué chez les praticiens des relations publiques, car leur vision de la profession en journalisme correspond à celle...... profession et de celle de leurs contreparties? Comment perçoivent-ils leurs rôles, leurs méthodes de travail et leurs interactions? Nous avons employé une méthode mixte, comprenant des entretiens en personne et des enquêtes en ligne, afin de recueillir et d’analyser les données. Les résultats indiquent que...

  16. Journal de la Recherche Scientifique de l'Université de Lomé - Vol 7 ...

    African Journals Online (AJOL)

    Approche conceptuelle pour un systeme expert distine a la modelisation des systemes aerosolaires autonomes avec batterie de stockage · EMAIL FULL TEXT EMAIL FULL ... realisation d'un programme de simulation du comportement thermique d'un batiment a usage d'habitation · EMAIL FULL TEXT EMAIL FULL TEXT

  17. Effets des extraits des feuilles de Alchornea cordifolia ...

    African Journals Online (AJOL)

    Faisant suite à deux études préliminaires, le but de cette étude est de rechercher, un effet antioxydant des feuilles de Alchornea cordifolia vis-à-vis du H2O2 relargué par le polynucléaire neutrophile stimulé. Deux extraits ont été préparés à partir des feuilles séchées : un macérât aqueux et un extrait à l'acétate d'éthyle.

  18. Promouvoir l'entrepreneuriat inclusif des jeunes et des femmes ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Un débat d'experts organisé par le CRDI s'attaque au mariage précoce lors du forum sur la condition des femmes à l'ONU. Des chercheurs appuyés par le CRDI parlent de leurs expériences au Comité sur les ONG lors du forum de la Commission de la condition de la femme. Voir davantageUn débat d'experts organisé par ...

  19. Impact des proprietes physicochimiques des sols de culture du ...

    African Journals Online (AJOL)

    La proportion moyenne de spores non-viables (55 %) est élevée. Il a été noté des corrélations positives entre les communautés de CMA et le magnésium (R = 0,65), la CEC (R = 0,69), l'argile (R = 0,74) et le limon grossier (R = 0,79). Par contre des corrélations négatives ont été obtenues avec le sable fin (R = -0,60) et le ...

  20. Evaluation economique des performances des services d'eau ...

    African Journals Online (AJOL)

    Abstract. En Algérie, le recours à des entreprises spécialisées dans la production et la distribution d'eau potable implique la nécessité de disposer d'évaluations du coût de ces activités. Cet article propose une étude micro-économétrique de la fonction de coût de l'alimentation en eau potable sur des données de panel, ...

  1. Evolution des intensites maximales annuelles des pluies horaires ...

    African Journals Online (AJOL)

    Ces résultats ne sont pas suffisants pour établir une relation entre les variations graduelles observées et le phénomène de changement climatique. La complexité du système climatique de l'Afrique de l'Ouest, la variabilité naturelle des données extrêmes et la longueur des séries utilisées suggèrent une prudence en la ...

  2. Evaluation des connaissances des enseignants du secondaire de l ...

    African Journals Online (AJOL)

    Evaluation des connaissances des enseignants du secondaire de l'atlantique au Benin sur les facteurs de risques du cancer du col de l'uterus en 2014. ... Les données ont été collectées à l'aide d'un questionnaire auto-administré. Une régression logistique pas à pas descendante a été faite. L'adéquation du modèle a été ...

  3. Comportement des polluants des eaux pluviales urbaines en ...

    African Journals Online (AJOL)

    C'est dans ce contexte que s'inscrit le présent travail qui porte sur la dégradation des paramètres organiques (DBO5, DCO, MES, O2, NO-3, pH, T, Fer, turbidité) dans différents milieux : naturel (rivière), canal artificiel, rivière (aux rives revêtues). Le traitement des données, effectué sur les trois sites d'observation sur deux ...

  4. Labellisation des miels et valorisation des spécifications régionales ...

    African Journals Online (AJOL)

    régionaux qui pilote les activités dénommé « Plate Forme Miel de Boeny ». Des outils ont été également conçus : des guides, des manuels, des supports de communication permettant de mieux gérer et de contrôles la qualité des miels. Des dispositifs de suivis et de contrôle sont en vue, mais aussi la création des ...

  5. Facteurs climatiques et environnementaux des risques palustres ...

    African Journals Online (AJOL)

    La santé des populations est tributaire des conditions climatiques et environnementales dans lesquelles elles vivent. La présente étude analyse les liens entre le climat, l'environnement et la prévalence du paludisme dans le Département des Collines. L'analyse des données pluviométriques, thermométriques et ...

  6. Etude des potentialites germinatives pour une regeneration ...

    African Journals Online (AJOL)

    Les différents aspects germinatifs du fruit de Neocarya macrophylla, ressource génétique fruitière spontanée du Niger, ont fait l'objet d'analyses. L'étude des performances germinatives de cette espèce a donc porté sur des graines récentes et des graines conservées à la température ambiante dans des flacons en verre ...

  7. Integration et exclusion des communautes : La curieuse ...

    African Journals Online (AJOL)

    Le sport s'est imposé aujourd'hui comme un puissant vecteur d'intégration. C'est par la médiation du sport que des individus et des cultures différentes se rencontrent, communient ensemble au cours des compétitions et finissent par se socialiser ou se « resocialiser ». C'est donc dire que le sport contribue à construire des ...

  8. ETUDE DE LA DISTRIBUTION DES CATIONS ECHANGEABLES

    African Journals Online (AJOL)

    SEI Joseph

    déterminé les pourcentages en silice et carbonates. Nous avons aussi mis au point la présence des ions chlorures en pourcentage assez important pouvant être responsable de la corrosion des aciers de frettage des tuyaux en béton précontraint et par conséquent des dégradations affectant ces tuyaux. La présence d'un.

  9. ETUDE DE LA DISTRIBUTION DES CATIONS ECHANGEABLES

    African Journals Online (AJOL)

    SEI Joseph

    pollution. L'objectif du présent travail est l'étude de la qualité des eaux superficielles et souterraines pour évaluer le degré de pollution provenant des lixiviats de la décharge et des cours d'eaux dans lesquels les ..... Les métaux lourds dosés ont montré une pollution métallique des eaux souterraine par rapport à la norme.

  10. Zur odonatenfauna des Fintlandsmoores (Landkreis ammerland)

    OpenAIRE

    Gueffroy, Daniel; Liekweg, Tammo

    2000-01-01

    Zur Untersuchung der Libellenfauna des Fintlandsmoores im Landkreis Ammerland wurden 1999 zehn Exkursionen durchgeführt. Der Untersuchungsschwerpunkt lag im bereich der dystrophen Torfstiche im süden sowie des unabgetorften Hochmoorrestes im Zentrum des Naturschutzgebietes. Insgesamt wurden 15 Libellenarten als bodenständig nachgewiesen. Aufgrund früherer Untersuchungen aus den Jahren 1973-78 und 1986 läßt sich die zunehmende Eutrophierung anhand der Veränderung des Artenspektr...

  11. ETUDE DE LA DISTRIBUTION DES CATIONS ECHANGEABLES

    African Journals Online (AJOL)

    SEI Joseph

    D'autre part, à cause de la corrélation directe entre l'étendue des inondations et les quantités de poissons et de pâturages fournies par la plaine, il y a eu dégradation des ... aux changements climatiques en zone sahélienne du Cameroun. Un des objectifs de notre étude était de préciser le comportement des agriculteurs ...

  12. L'atténuation intrinsèque des ondes sismiques. Deuxième partie : Théorie et modèles Intrinsic Attenuation of Seismic Waves. Part Two: Theory and Models

    Directory of Open Access Journals (Sweden)

    Bourbie T.

    2006-11-01

    Full Text Available Le comportement d'une roche plus ou moins saturée est assimilé à un comportement visco-élastique linéaire. Cette théorie est examinée pour un milieu à une ou trois dimensions d'espace. Il est montré que les ondes planes se propageant dans un milieu visco-élastique linéaire sont des ondes inhomogènes c'est-à-dire des ondes pour lesquelles les plans de phase constante ne sont pas parallèles aux plans d'amplitude constante. La notion de facteur de qualité est définie en fonction de l'énergie perdue par cycle. Les calculs montrent que le facteur de qualité n'est plus seulement fonction des caractéristiques anélastiques du milieu traversé mais aussi de l'inhomogénéité de l'onde considérée, cette dépendance étant négligeable loin de l'angle critique. Enfin, il est montré l'effet du contraste d'atténuation sur les réflexions à l'interface entre deux milieux visco-élastiques. Quelques modèles importants sont examinés en détail à savoir les modèles élémentaires de ressorts et pots visqueux, le modèle de Zener et le modèle à Q-constant. Il est montré comment le modèle à Q-constant peut être considéré comme une somme de modèles de Zener, chacun d'entre eux caractérisant une inclusion particulière. The mechanical behavior of a more or less saturated rock is assumed to be linear visco-elastic. This theory is examined for a one- or three-dimensional space medium. Plane waves propagating in a linear visco-elastic medium are shown to be inhomogeneous waves, i. e. waves for which the constant-phase planes are not parallel to the constant-amplitude planes. The concept of quality factor is defined as a function of the energy loss per cycle. It is shown that the quality factor is a function not only of the anelastic properties of the medium crossed through but also of the inhomogeneity of the wave considered. This dependence is negligible far from the critical angle. The effect of attenuation contrast on

  13. Joint Inversion of Fracture Model Properties for CO2 Storage Monitoring or Oil Recovery History Matching Inversion conjointe des propriétés d’un modèle de fractures pour le monitoring d’un stockage de CO2 ou le calage d’un historique de production

    Directory of Open Access Journals (Sweden)

    Verscheure M.

    2012-06-01

    Full Text Available For oil recovery or CO2 storage, “reservoirs” are commonly used to designate geological structures where oil can be found or CO2 can be stored. All reservoirs present a heterogeneity in terms of rock type and properties (such as porosity and permeability. In addition, some of these reservoirs present fractures and faults. Fractured reservoirs are an important part of the oil reserves in the world (Middle East, Gulf of Mexico, etc. and some of them are important reservoirs in terms of oil volume and productivity in spite of the fractures. In addition, studies of reservoirs for geologic storage of CO2 have shown the existence of diffuse fractures and faults and their strong impacts on flow. A key point in fractured reservoirs is to understand the geometry and hydraulic conductivity of the network formed by the fractures. This requires the construction of a reservoir model that integrates all available conceptual knowledge and quantitative data. The topic of the present paper deals with a new methodology able to perform the history matching of a fractured reservoir model by adapting the sub-seismic fault properties and positions. The main difficulty of this work is to generate a sub-seismic fault network whose fault positions can be easily modified while respecting the statistical fault model. The sub-seismic fault model we have chosen allows us to obtain a sub-seismic fault network that is consistent with the seismic fault network and that succeeds in capturing the specific spatial organization of the faults. In a first step, the geometry of the seismic fault network is characterized using fractal methods. Sub-seismic faults are then generated according to a stochastic algorithm. Finally, the geometry of this discrete fracture network is optimized in order to match the hydrodynamic data about the reservoir. The optimization algorithm modifies the sub-seismic fault positions, leading to the history matching of the reservoir model. Fractal

  14. LES APPROCHES PSYCHOSOCIOLOGIQUES DES ORGANISATIONS

    Directory of Open Access Journals (Sweden)

    Deaconu Alecxandrina

    2008-05-01

    Full Text Available Les préoccupations pour bien comprendre la complexité des organisations sont bien connues dans la théorie et la pratique du management. La motivation la plus fréquente pour toutes les recherches et les investigationes faites a été fondée sur le besoin de savoir gérer les situations diverses en vue de maximiser la performance organisationnelle. En ce qui nous concerne, pour enrichir les informations disponibles, nous voulons élargir, dans notre communication, les approches traditionelles, focaliser l’attention sur la dimension psychologiques des organisations et présenter les mécanismes qui favorisent l’implication des salariés.

  15. Parasites et parasitoses des poissons

    OpenAIRE

    De Kinkelin, Pierre; Morand, Marc; Hedrick, Ronald; Michel, Christian

    2014-01-01

    Cet ouvrage, richement illustré, offre un panorama représentatif des agents parasitaires rencontrés chez les poissons. S'appuyant sur les nouvelles conceptions de la classification phylogénétique, il met l'accent sur les propriétés biologiques, l'épidémiologie et les conséquences cliniques des groupes d'organismes en cause, à la lumière des avancées cognitives permises par les nouveaux outils de la biologie. Il est destiné à un large public, allant du monde de l'aquaculture à ceux de la santé...

  16. L’Internet des objets

    OpenAIRE

    Benghozi, Pierre-Jean; Bureau, Sylvain; Massit-Folléa, Françoise

    2012-01-01

    L’ « internet des objets » est une dimension majeure de l’internet du futur. Mais tout le monde ne s’accorde pas encore sur sa définition, ni sur la mesure de son importance économique ou des risques qu’il induit. L’étude de nombreux rapports prospectifs et l’observation des innovations d’ores et déjà engagées a permis de mettre en relief les incertitudes techniques, économiques et socio-politiques qui pèsent sur cette véritable mutation programmée de l’internet et de proposer une approche eu...

  17. Aux origines des Jeux olympiques.

    Directory of Open Access Journals (Sweden)

    Isabelle Debilly

    2005-11-01

    Full Text Available Si les Jo modernes sont régulièrement sous les feux de l’actualité, soit par la répétition temporelle des Olympiades elle-même, soit par les enjeux économiques féroces qui découlent du choix des lieux, ceux de l’Antiquité sont en général cantonnés au domaine scolaire ou universitaire. Néanmoins, ils bénéficient tous les quatre ans d`un éclairage médiatique. L’ouvrage Olympie. La victoire pour les dieux est au croisement des deux domaines. En effet, écrit par un ...

  18. Agent des projets et des partenariats (h/f) | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    appuie la coordination des activités de mobilisation de ressources et des bailleurs de fonds (politiques et planification, etc.) et l'appui au Comité de gestion de la haute direction et au Conseil des gouverneurs;; facilite des relations clés entre la DPDA et des clients (programmes et bureaux régionaux), le conseiller juridique ...

  19. Quantification des apports et des exores d'un lac : cas du lac Fetzara ...

    African Journals Online (AJOL)

    ... permet de déterminer l'impact des facteurs environnementaux sur les variations de la composition chimique des eaux aux entrées et à la sortie du lac. Les résultats des analyses chimiques couplés aux débits mesurés dans différents points des Oueds Zied, Mellah, Hout et Meboudja ont permis le calcul des flux transitant ...

  20. Potentiel en biogaz des résidus agropastoraux et des excréments ...

    African Journals Online (AJOL)

    La potentialité en biogaz des excréments humains et des résidus agropastoraux du bassin versant du fleuve Sassandra (BVS) a été évaluée à partir des statistiques agricoles et de la population, ainsi que des indices de productivité de biogaz. Egalement, la mise en oeuvre des technologies de production de biogaz dans ...

  1. Prise en charge des urgences au service d'accueil des urgences ...

    African Journals Online (AJOL)

    Introduction: La prise en charge des patients dans les services d'accueil des urgences est une des meilleures vitrines d'un système de santé. En Afrique subsaharienne, la gestion des urgences se heurte à des difficultés humaines et matérielles. Le but de ce travail était d'évaluer les difficultés de prise en charge au Service ...

  2. Synthèse des faits empiriques et des leçons : Comment l ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    5 déc. 2013 ... and Flora Hewlett Foundation, le programme Croissance de l'Économie et Débouchés Économiques des Femmes ... des enseignements tirés au sujet des liens qui existent entre l'autonomisation économique des femmes ..... examens systématiques à l'aide des principes Cochrane/Campbell/3iE. Toutefois ...

  3. Récupération des eaux grises et des eaux pluviales pour l ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Récupération des eaux grises et des eaux pluviales pour l'agriculture urbaine et périurbaine à La Soukra, dans le gouvernorat d'Ariana (Tunisie). Jusqu'à la fin des années 1960, la plaine de la Soukra était une zone de verdure adjacente à Tunis. Au début des années 1970, les agriculteurs utilisaient des eaux usées ...

  4. Kodifikation des Privatrechts in Ungarn und die Tradition des römischen Rechts

    OpenAIRE

    Hamza, Gabor

    2015-01-01

    Das erste ungarische Zivilgesetzbuch wurde im Jahre 1959 verabschiedet. Das ungarische Zivilgesetzbuch ist am 1. Mai 1960 in Kraft getreten. Das ZGB spiegelt den Einfluss des schweizerischen Zivilgesetzbuches, des schweizerischen Obligationenrechts, des deutschen BGB und des Entwurfes des ungarischen Bürgerlichen Gesetzbuches aus dem Jahre 1928 wider. Das ungarische ZGB hat keinen Allgemeinen Teil, sondern nur in sieben Paragraphen gegliederte einleitende Bestimmungen. Der Kodex gliedert sic...

  5. Étude des politiques relatives à l'établissement des prix et à la ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Étude des politiques relatives à l'établissement des prix et à la taxation de l'alcool en Inde. L'Inde est le troisième marché mondial pour les ... Les données proviendront de sources multiples, dont le National Sample Survey Office et les départements des taxes d'accise des dix États. En fonction des résultats obtenus, les ...

  6. Architecture, des normes et des systèmes d'information libres, phase ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Architecture, des normes et des systèmes d'information libres, phase II (OASIS II) - Renforcement des capacités dans l'ensemble de l'Afrique. Sur presque tout le continent africain, la prestation des services de santé est limitée en raison des maigres ressources disponibles et de la charge de morbidité de plus en plus ...

  7. Intensifier l'inclusion financière des femmes et des jeunes en Afrique ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Intensifier l'inclusion financière des femmes et des jeunes en Afrique subsaharienne. Bien que d'énormes progrès aient été accomplis en vue d'offrir des services financiers à un plus large éventail de clients dans de nombreux pays de l'Afrique subsaharienne, des femmes et des jeunes marginalisés sont toujours laissés ...

  8. Perceptions locales de la manifestation des changements ...

    African Journals Online (AJOL)

    SARAH

    . PRPR. ERMA. DC. UD cluster 1 cluster 2. Pauvres. Riches et moyens. Figure 4. Positionnement des classes d'impacts socio-économiques des changements climatiques dans un système d'axes de l'analyse factorielle des ...

  9. Die Problematik des Begriffes hebraica veritas

    African Journals Online (AJOL)

    p1243322

    Nach ihm waren sowohl der Text des Tanak als auch sein Umfang Ausdruck der wahren Offenbarung Gottes an Israel, daher konnte nur diese Form des Alten Testaments die Wahrheit erhalten. Folgerichtig betrachtete er sie als Bibel der Verfasser des Neuen. Testaments und Norm für Lehre und Leben. Untersucht man die.

  10. Pecheries maritimes artisanales Togolaises : analyse des ...

    African Journals Online (AJOL)

    Pecheries maritimes artisanales Togolaises : analyse des debarquements et de la valeur commerciale des captures. K.M. Sedzro, E.D. Fiogbe, E.B. Guerra. Abstract. Description du sujet : La connaissance scientifique de la pression des pêcheries artisanales sur les ressources marines togolaises s'avère nécessaire pour ...

  11. Migration transnationale des Vietnamiennes en Asie | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Souvent, cependant, les pays d'origine ne disposent pas des politiques ni des lois ayant force exécutoire qui permettraient d'assurer des pratiques d'embauche ... Women's movements in India are struggling to address problems arising from rapidly changing social relations and vulnerabilities associated with, among other ...

  12. Verona Coding Definitions of Emotional Sequences (VR-CoDES): Conceptual framework and future directions.

    Science.gov (United States)

    Piccolo, Lidia Del; Finset, Arnstein; Mellblom, Anneli V; Figueiredo-Braga, Margarida; Korsvold, Live; Zhou, Yuefang; Zimmermann, Christa; Humphris, Gerald

    2017-12-01

    To discuss the theoretical and empirical framework of VR-CoDES and potential future direction in research based on the coding system. The paper is based on selective review of papers relevant to the construction and application of VR-CoDES. VR-CoDES system is rooted in patient-centered and biopsychosocial model of healthcare consultations and on a functional approach to emotion theory. According to the VR-CoDES, emotional interaction is studied in terms of sequences consisting of an eliciting event, an emotional expression by the patient and the immediate response by the clinician. The rationale for the emphasis on sequences, on detailed classification of cues and concerns, and on the choices of explicit vs. non-explicit responses and providing vs. reducing room for further disclosure, as basic categories of the clinician responses, is described. Results from research on VR-CoDES may help raise awareness of emotional sequences. Future directions in applying VR-CoDES in research may include studies on predicting patient and clinician behavior within the consultation, qualitative analyses of longer sequences including several VR-CoDES triads, and studies of effects of emotional communication on health outcomes. VR-CoDES may be applied to develop interventions to promote good handling of patients' emotions in healthcare encounters. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Development of a thermal hydraulic modelling of ground water of the Malm in the Munich metropolitan area; Entwicklung einer thermisch-hydraulischen Grundwassermodellierung des Malm im Grossraum Muenchen

    Energy Technology Data Exchange (ETDEWEB)

    Dussel, M.; Lueschen, E.; Thomas, R. [Leibniz-Institut fuer Angewandte Geophysik, Hannover (DE)] (and others)

    2011-10-24

    The mutual potential influence of geothermal duplicates and the scientific investigation of the relationship between seismic and hydraulic parameters are investigated in the joint research project 'Geothermal characterization of fractured karst limestone aquifers in the Munich metropolitan area'. Thirteen doublets and triplets being in production or sunk illustrate the great geothermal potential and provide important data on the development of a thermal-hydraulic modeling of the reservoir. 3D seismic Unterhaching, 3D structural model, hydrogeological model and a high-resolution 3D temperature model form the basis of the numerical modeling. Different seismic signatures, seismic attributes and variations in the interval velocities characterize the ground geophysically, and were interpreted under consideration of geological and hydrogeological background information as well as borehole measurements in terms of hydraulically conductive homogeneous areas. For the Munich metropolitan area, the numerical modeling is a decision aid for the future optimized and sustainable hydrothermal utilization of the Malm aquifer.

  14. Extraction of overlapping radiation-induced magnetoresistance oscillations and bell-shaped giant magnetoresistance in the GaAs/AlGaAs 2DES using a multiconduction model

    Science.gov (United States)

    Samaraweera, R. L.; Liu, H. C.; Wang, Z.; Wegscheider, W.; Mani, R. G.

    2017-06-01

    We present an experimental study aimed at extracting the microwave radiation-induced magnetoresistance oscillations from the bell-shape giant magnetoresistance in high mobility GaAs/AlGaAs devices using a multi-conduction model. The results show that the multi-conduction model describes the observed giant magnetoresistance effect and the model helps to extract radiation-induced magnetoresistance oscillations, over a wider parameter space.

  15. Modeling of the water gap in BWR fuel elements using SCALE/TRITON; Modellierung des Wasserspalts bei SWR-BE mit SCALE/TRITON

    Energy Technology Data Exchange (ETDEWEB)

    Tittelbach, S.; Chernykh, M. [WTI Wissenschaftlich-Technische Ingenieurberatung GmbH, Juelich (Germany)

    2012-11-01

    The authors show that an adequate modeling of the water gap in BWR fuel element models using the code TRITON requires an explicit consideration of the Dancoff factors. The analysis of three modeling options reveals that considering the moderating effects of the water gap coolant for the peripheral fuel elements the resulting deviations of the U-235 and Pu-239 concentrations are significantly reduced. The increased temporal calculation efforts are justified with respect to the burnup credits for criticality safety analyses.

  16. Modeling and numerical study of two phase flow; Modelisation et etude numerique d'ecoulements diphasiques: 1- Modelisation d'un ecoulement homogene equilibre 2- Modelisation des collisions entre gouttelettes a l'aide d'un modele simplifie de type BGK

    Energy Technology Data Exchange (ETDEWEB)

    Champmartin, A.

    2011-02-28

    This thesis describes the modelization and the simulation of two-phase systems composed of droplets moving in a gas. The two phases interact with each other and the type of model to consider directly depends on the type of simulations targeted. In the first part, the two phases are considered as fluid and are described using a mixture model with a drift relation (to be able to follow the relative velocity between the two phases and take into account two velocities), the two-phase flows are assumed at the equilibrium in temperature and pressure. This part of the manuscript consists of the derivation of the equations, writing a numerical scheme associated with this set of equations, a study of this scheme and simulations. A mathematical study of this model (hyperbolicity in a simplified framework, linear stability analysis of the system around a steady state) was conducted in a frame where the gas is assumed baro-tropic. The second part is devoted to the modelization of the effect of inelastic collisions on the particles when the time of the simulation is shorter and the droplets can no longer be seen as a fluid. We introduce a model of inelastic collisions for droplets in a spray, leading to a specific Boltzmann kernel. Then, we build caricatures of this kernel of BGK type, in which the behavior of the first moments of the solution of the Boltzmann equation (that is mass, momentum, directional temperatures, variance of the internal energy) are mimicked. The quality of these caricatures is tested numerically at the end. (author) [French] Cette these decrit la modelisation et la simulation de systemes a deux phases composees de particules evoluant dans un gaz. Les deux phases interagissent entre elles et le type de modele a considerer depend directement du type de simulations envisagees. Dans une premiere partie, les deux phases sont considerees comme des fluides, elles sont decrites a l'aide d'un modele de melange avec une relation de derive (permettant de

  17. Modelling the high temperature behaviour of a technical relevant TiAl-alloy; Modellierung des Hochtemperaturverhaltens einer technisch relevantenTiAl-Legierung

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, R.; Brocks, W. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

    2000-07-01

    The design of components of metallic high-temperature materials by the finite element method requires the application of phenomenological viscoplastic material models. The route from the choice of a convenient model, the numerical integration of the equations and the parameter identification to the design of components is described. The Chaboche-model is used whose evolution equations are explicitly integrated. The parameters are determined by graphical and numerical methods in order to use the material model for describing the deformation behaviour of an intermetallic titanium aluminide alloy. (orig.)

  18. Models for the Behavior of Offshore Structure Foundations. Part Two: Applications to Structural Design and Quality Assurance Processes Modèles pour le comportement des fondations d'ouvrages types marins. Deuxième partie : applications au calcul d'ouvrage et processus d'assurance qualité

    Directory of Open Access Journals (Sweden)

    Meimon Y.

    2006-11-01

    Full Text Available Designing the foundations of offshore structures is a complex task, requiring both expert experience and the use of numerical models for safety insurance and design cost optimization. In fact, forecasting foundation behavior demands a correct evaluation of the combined effects of construction phasing, spatial variability of the soil mechanical properties, uncertainties on the applied loadings and due to the geomaterial mechanical modeling techniques. For offshore platforms, this is compounded by the hazardous nature of environmental loadings. These loadings, which are often very severe, could have disastrous effects on structure behavior. This dissertation presents the synthesis of a ten-year research program, developed by a team of Institut Français du Pétrole, with the cooperation of university teams, technical centers and industrial companies. The objective was to set up methodologies and numerical tools for the behavior of typical offshore structure foundations, spanning their entire life. It is presented in two distinct parts. The first part presents specific methodologies for the soil/structure interaction analysis of offshore platforms, and discusses the development of rheological models for soil behavior under non-monotonous loading. The second part considers the use of these sophisticated models for analyzing offshore structure foundations. It shows how these models are integrated in the FONDOF/IFP software, by using the finite element method coupled with algorithms specific to the problems posed by offshore foundations. Several applications are presented, demonstrating the ability of these methods to describe observed phenomena. A special place is reserved for the description of a quality assurance process developed by the French GRECO CNRS 'Geomaterials' Group of university teams, technical centers and industrial companies. The steps of a process for validating constitutive models are applied to a typical shallow foundation

  19. Caractérisation des plantes médicinales à flavonoïdes des marchés ...

    African Journals Online (AJOL)

    Les plantes à flavonoïdes constituent un atout majeur pour le maintien de la santé. Le présent travail a été conduit dans deux marchés de la ville de Douala afin de valoriser l'utilisation des plantes à flavonoïdes dans la médecine traditionnelle. Des enquêtes ethnobotaniques réalisées auprès de 40 vendeurs des plantes ...

  20. Cardiotoxicité des psychotropes

    OpenAIRE

    TAHIRI, Abdallah

    2013-01-01

    Même à dose thérapeutique, les médicaments psychotropes sont susceptibles d'engendrer des troubles du rythme cardiaque graves avec risque létal concourant à expliquer la pré valence de la mort subite dans la population psychiatrique. Les situations cliniques à risque telles que poly médication (des psychotropes entre eux ou d'un psychotrope avec un non psychotrope allongeur de QTc), interactions médicamenteuses aussi bien pharmacodynamiques que pharmacocinétiques, traitement pa...

  1. (AJST) BIOSTRATIGRAPHIE DES FORAMINIFERES ET ...

    African Journals Online (AJOL)

    2Département de Géologie, Faculté des Sciences, Université d'Ibadan, Ibadan, Nigeria. 3Département de Géologie et Sciences de l'Environnement, Université de Buea, Cameroun. ARESUME:- 115 déblais de sondage et des ..... Cette méthode a été appliquée au lieu de la première apparition et de la denière apparition ...

  2. Contribution des radios communautaires a l'education des ...

    African Journals Online (AJOL)

    TIC » ont sur l'éducation des adolescents. Par une démarche d'étude essentiellement transversale, quantitative et qualitative, nous avons interrogé 160 sujets et les données collectées ont fait découvrir autant d'influences positives que ...

  3. Cartographie des zones d'intervention des partenaires techniques et ...

    African Journals Online (AJOL)

    Il s'agit des Communes ayant 7 à 10 partenaires (niveau 1), les. Communes ayant 11 à 14 (niveau 2) et les Communes ayant plus de 15 partenaires (niveau 3). Mots clés : Cartographie, Bénin, zones d'intervention, partenaires techniques et financiers (PTF), taux spatial d'intervention (TSI), taux de population couverte ...

  4. Traits morphologiques des graines et vigueur des jeunes plants de ...

    African Journals Online (AJOL)

    écologique du Sénégal afin de pouvoir sélectionner une meilleure semence qui sera destinée aux programmes de développement des énergies renouvelables. Morphological traits of seeds and seedling vigor of two sources of Jatropha curcas L. in ...

  5. Traits morphologiques des graines et vigueur des jeunes plants de ...

    African Journals Online (AJOL)

    SARAH

    écologique du Sénégal afin de pouvoir sélectionner une meilleure semence qui sera destinée aux programmes de développement des énergies renouvelables. Journal of Applied Biosciences 88:8249– 8255. ISSN 1997–5902 ...

  6. Evaluation des conditions de germination des noyaux de Grewia ...

    African Journals Online (AJOL)

    personnel

    31 janv. 2014 ... 1Laboratoire de Physiologie et Production Végétales, Université Marien NGOUABI,. Faculté des Sciences et Techniques, BP.69. Brazzaville, Republique du Congo. 2Ecole Nationale Supérieure d'Agronomie et Forestérie, Université Marien NGOUABI,. BP. 69. Brazzaville, Republique du Congo.

  7. An Integrated Model for Computer Aided Reservoir Description : from Outcrop Study to Fluid Flow Simulations Un logiciel intégré pour une description des gisements assistée par ordinateur : de l'étude d'un affleurement aux simulations de l'écoulement des fluides

    Directory of Open Access Journals (Sweden)

    Guerillot D.

    2006-11-01

    Full Text Available An accurate understanding of the internal architecture of a reservoir is required to improve reservoir management for oil recovery. Geostatistical methods give an image of this architecture. The purpose of this paper is to show how this lithological description could be used for reservoir simulation. For this purpose, scale averaging problems must be solved for non-additive variables. A method giving a full effective permeability matrix is proposed. The integrated software described here starts from core analysis and lithologic logs to provide data for reservoir simulators. Each of the steps of this interactive and graphic system is explained here. Pour faire de bonnes prévisions de production pour un gisement pétrolifère, il est nécessaire de connaître précisément son architecture interne. Les méthodes géostatistiques donnent une représentation de cette architecture. L'objectif de cet article est de montrer une façon d'utiliser cette description lithologique pour la simulation des réservoirs. Il faut alors résoudre des problèmes de changement d'échelle pour les variables qui ne sont pas additives. On propose une méthode d'estimation de la perméabilité effective sous la forme d'une matrice pleine. Le logiciel intégré que l'on décrit part de l'analyse des carottes et des diagraphies en lithologies et fournit des données pour les simulateurs de gisement. On détaille ici chaque étape de ce système interactif graphique.

  8. Mechanical disequilibria in two-phase flow models: approaches by relaxation and by a reduced model; Modelisation des desequilibres mecaniques dans les ecoulements diphasiques: approches par relaxation et par modele reduit

    Energy Technology Data Exchange (ETDEWEB)

    Labois, M

    2008-10-15

    This thesis deals with hyperbolic models for the simulation of compressible two-phase flows, to find alternatives to the classical bi-fluid model. We first establish a hierarchy of two-phase flow models, obtained according to equilibrium hypothesis between the physical variables of each phase. The use of Chapman-Enskog expansions enables us to link the different existing models to each other. Moreover, models that take into account small physical unbalances are obtained by means of expansion to the order one. The second part of this thesis focuses on the simulation of flows featuring velocity unbalances and pressure balances, in two different ways. First, a two-velocity two-pressure model is used, where non-instantaneous velocity and pressure relaxations are applied so that a balancing of these variables is obtained. A new one-velocity one-pressure dissipative model is then proposed, where the arising of second-order terms enables us to take into account unbalances between the phase velocities. We develop a numerical method based on a fractional step approach for this model. (author)

  9. Models for the Behavior of Offshore Structure Foundations. Part One: Methodologies and Rheological Models for Soils Modèles pour le comportement des fondations d'ouvrages types marins. Première partie : Méthodologies et modèles rhéologiques de sols

    Directory of Open Access Journals (Sweden)

    Meimon Y.

    2006-11-01

    Full Text Available Designing the foundations of offshore structures is a complex task, requiring both expert experience and the use of numerical models for safety insurance and design cost optimization. In fact, forecasting foundation behavior demands a correct evaluation of the combined effects of construction phasing, spatial variability of the soil mechanical properties, uncertainties on the applied loadings and due to the geomaterial mechanical modeling techniques. For offshore platforms, this is compounded by the hazardous nature of environmental loadings. These loadings, which are often very severe, could have disastrous effects on structure behavior. This dissertation presents the synthesis of a ten-year research program, developed by a team of Institut Français du Pétrole, with the cooperation of university teams, technical centers and industrial companies. The objective was to set up methodologies and numerical tools for the behavior of typical offshore structure foundations, spanning their entire life. It is presented in two distinct parts. The first part presents specific methodologies for the soil/structure interaction analysis of offshore platforms, and discusses the development of rheological models for soil behavior under non-monotonous loading. The second part considers the use of these sophisticated models for analyzing offshore structure foundations. It shows how these models are integrated in the FONDOF/IFP software, by using the finite element method coupled with algorithms specific to the problems posed by offshore foundations. Several applications are presented, demonstrating the ability of these methods to describe observed phenomena. A special place is reserved for the description of a quality assurance process developed by the French GRECO CNRS 'Geomaterials' Group of university teams, technical centers and industrial companies. The steps of a process for validating constitutive models are applied to a typical shallow foundation

  10. Applicability of reference grid models for regulation of German electricity grids. An exemplary approach; Eignung von Referenznetzmodellen fuer die Regulierung deutscher Stromnetze. Beispiel des KeL-Ansatzes

    Energy Technology Data Exchange (ETDEWEB)

    Lieb-Doczy, E. [Economic Consulting, Deloitte and Touche LLP, London (United Kingdom)

    2006-11-20

    Regulation by incentives is to ensure long-term efficient and reliabile operation of power grids. The contribution disputes whether reference grid models should be part of the incentives regulation model of the German power sector. As an example, it is discussed whether the principles applied in telecommunication networks, i.e. cost of efficient service, may be applicable in the elctricity sector as well. (orig.)

  11. Deformable object model and simulation. Application to lung cancer treatment; Modelisation et simulation parametrable d'objets deformables. Application aux traitements des cancers pulmonaires

    Energy Technology Data Exchange (ETDEWEB)

    Baudet, V

    2006-06-15

    Ionising treatment against cancers such as conformal radiotherapy and hadron therapy are set with error margins that take into account statistics of tumour motions, for instance. We are looking for reducing these margins by searching deformable models that would simulate displacements occurring in lungs during a treatment. It must be personalized with the geometry obtained from CT scans of the patient and also it must be parameterized with physiological measures of the patient. In this Ph. D. thesis, we decided to use a mass-spring system to model lungs because of its fast and physically realist deformations obtained in animation. As a starting point, we chose the model proposed by Van Gelder in order to parameterize a mass-spring system with rheological characteristics of an homogeneous, linear elastic isotropic material in two dimensions (2D). However, we tested this model and proved it was false. Hence we did a Lagrangian study in order to obtain a parametric model with rectangular in 2D (cubic in 3D) elements. We also determined the robustness by testing with stretching, inflating, shearing and bending experiments and also by comparing results with other infinite element method. Thus, in this Ph.D. thesis, we explain how to obtain this parametric model, and how it will be linked to physiological data and how accurate it will be. (author)

  12. La maison des mathématiques

    CERN Document Server

    Villani, Cédric; Moncorgé, Vincent

    2014-01-01

    Comment travaillent les mathématiciens ? C'est peut-être en se promenant dans les couloirs de la première des " maisons des mathématiques " de France, l'institut Henri Poincaré, que l'on trouvera quelques réponses. Le mathématicien Cédric Villani et le physicien Jean-Philippe Uzan nous invitent à découvrir cette discipline et ses acteurs. Au fil des pages on suit, à travers de superbes images signées du photographe Vincent Moncorgé, la façon dont se fabrique cette science qui reste souvent mystérieuse. Toutes les dimensions, scientifique, esthétique et poétique, des mathématiques sont convoquées grâce à des regards croisés : la diversité des inspirations des chercheurs, la source de leur créativité, l'imaginaire littéraire et artistique des mathématiques, la drôle de tribu des mathématiciens. Un voyage au cœur de cette " auberge espagnole " des mathématiques, campus " à la française " accueillant des centaines de chercheurs du monde entier, devenu un lieu d'émulation et d'éc...

  13. Etude des erreurs d'estimation des populations par la méthode des captures successives (DeLURY, 2 captures et des captures-recaptures (PETERSEN

    Directory of Open Access Journals (Sweden)

    LAURENT M.

    1978-01-01

    Full Text Available L'estimation des populations naturelles par capture-recapture et par captures successives est souvent entachée d'erreur car, dans de nombreux cas, l'hypothèse fondamentale d'égalité des probabilités de captures pour tous les individus dans le temps et dans l'espace n'est pas respectée. Dans le cas des populations de poissons envisagés ici, les captures ont lieu par la pêche électrique. On a pu chiffrer l'ordre de grandeur des erreurs systématiques faites sur l'estimation des peuplements, en fonction des conditions particulières, biotiques et abiotiques, des différents milieux inventoriés.

  14. REPARTITION BRANCHIALE DES MONOGENES Gotocotyla ...

    African Journals Online (AJOL)

    AISA

    Sur la base des données recoltées, nous avons défini et discuté de la localisation branchiale de ces deux monogènes dans le cas d'infestations monospécifiques et .... et Pyragraphorus hollisae. Monospecific infections of Trachinotus ovatus with Gotocotyla acanthura and. Pyragraphorus hollisae. Nbre = Nombre ...

  15. Les parcs des porcelainiers Haviland

    Directory of Open Access Journals (Sweden)

    Colette Chabrely

    2012-04-01

    Full Text Available Les parcs du Reynou et de Mont-Méry en Limousin, anciennes propriétés des porcelainiers Haviland, présentent l’un et l’autre un grand intérêt paysager et botanique. Dans les deux cas, l’attribution de la création est incertaine. Cet article propose pour le Reynou une analyse de documents figurés anciens permettant de préciser la chronologie des travaux du château et du parc. Pour Mont-Méry il s’agit de poser de nouveaux jalons pour une étude plus approfondie des sources et de la composition des jardins afin d’envisager de nouvelles pistes pour leur attribution.The Reynou and Mont-Méry parks near Limoges originally belonged to the city’s porcelain manufacturers, the Havilands. Both parks are of considerable interest in terms of their landscaping and their botany. In both cases, there is some uncertainty as to the identity of their designers. This article offers an analysis of the graphic representations of the Reynou park, clarifying the chronology of the creation of the château and its park. For the Mont-Méry park, the aim is to offer some guidelines for further research in the source material and on the design of the park itself, perhaps allowing for the designer to be identified.

  16. Reduction des effectifs ou licenciements

    CERN Multimedia

    Maiani, Luciano

    2002-01-01

    "Vous faites un amalgame entre la reduction en cours des effectifs du CERN (organisation europeenne pour la recherche nucleaire) et les economies que le laboratoire doit realiser dans les cinq ans a venir pour financer le projet de grand collisionneur de hadrons (Le Monde du 4 septembre)" (1/2 page).

  17. Neue Lycaeniden des Leiderner Museums

    NARCIS (Netherlands)

    Fruhstorfer, H.

    1916-01-01

    Einige Exemplare aus der Lycaena cleotas Guér.-Gruppe des Leidener Museums veranlassten mich das Material meiner Sammlung und meine Übersicht übe die Formen der Gattung Luthrodes, Iris 1915, pp. 47-49, nochmals nachzuprüfen. Bei dieser Gelegenheit fand ich, dass die unbedeutende Chilades laius Cram,

  18. Globalisation des marchés de capitaux et valorisation des actifs financiers

    OpenAIRE

    Dominique Pepin

    2000-01-01

    Ce papier examine les effets de la libéralisation ou globalisation des marchés de capitaux sur les prix des actifs financiers. La comparaison des modèles de segmentation (douce) et d'intégration des marchés montre que la libéralisation des marchés a pour effet de favoriser la hausse des prix des actifs. Nous montrons que ce résultat ne résiste pas à une généralisation de l'analyse. La prise en compte du caractère multiple et simultanée des processus de libéralisation des marchés de capitaux a...

  19. Marine and fluvial facies modelling at petroleum reservoir scale; Modelisation des heterogeneites lithologiques a l'echelle du reservoir petrolier en milieu marin et fluviatile

    Energy Technology Data Exchange (ETDEWEB)

    Leflon, B.

    2005-10-15

    When modelling a petroleum reservoir, well data are very useful to model properties at a sub-seismic scale. Petrophysical properties like porosity or permeability are linked to the rock-type. Two methods based on well data have been developed to model facies. The first one is used to model marine carbonates deposits. The geometry of sedimentary layers is modelled through a special parameterization of the reservoir similar to Wheeler space. The time parameter is defined along the well paths thanks to correlations. The layer thickness is then extrapolated between wells. A given relationship between facies and bathymetry of sedimentation makes it possible to compute bathymetry along the well paths. Bathymetry is then extrapolated from wells and a reference map using the concept of accommodation. The model created this way is stratigraphically consistent. Facies simulation can then be constrained by the computed bathymetry. The second method describes a novel approach to fluvial reservoirs modelling. The core of the method lies in the association of a fairway with the channels to be simulated. Fairways are positioned so that all data are taken in account; they can be stochastic if unknown or explicitly entered if identified on seismic data. A potential field is defined within the fairway. Specifying a transfer function to map this potential field to thickness results in generating a channel inside the fairway. A residual component is stochastically simulated and added to the potential field creating realistic channel geometries. Conditioning to well data is obtained by applying the inverse transfer function at the data location to derive thickness values that will constrain the simulation of residuals. (author)

  20. Modelling of the ultrasonic inspection of steel tubes with longitudinal defects; Modelisation du controle ultrasonore de tubes d`acier presentant des defauts de type ``entaille longitudinale``

    Energy Technology Data Exchange (ETDEWEB)

    Mephane, M

    1998-12-31

    A model has been developed in order to simulate the ultrasonic inspection of steel tubes in the Vallourec control configuration. The model permits to simulate the control of steel tubes showing longitudinal defects located near the internal or external surface of tubes which appear during the rolling process. To detect this kind of defect, the probe is placed in an incident place perpendicular to the tube`s axis. The probe is in front of the external surface of the tube. The main characteristics of the model is to assume that the field radiated in the material does not depend on the probe`s position. This assumption permits to treat separately the field retracted in the material and the interaction between the defect and the ultrasonic beam. The focal plane is located in the material, so the plane waves approximation is applied where the waves front are assumed plane and parallel. The parallel refracted beam becomes divergent after reflection on the internal surface of tube. To treat the beam divergence, an amplitude weighting coefficient is then calculated by mean of the energy conservation of a tube of rays before and after reflection, following the Snell laws. This model can predict the edge diffraction echoes, the echoes issued from the corner effect, and also the mode conversion echoes. It has been validated on artificial notches, and on some natural defects. A comparison between experimental and modelling results shows a good agreement. (author) 39 refs.

  1. Amelioration de l'implementation des volets dans un modele de dynamique et controle de vol de l'avion L1011-500

    Science.gov (United States)

    Saafi, Kais

    The aerodynamic model of the aircraft L1011-500 was designed and simulated in Matlab and Simulink by Bombardier to serve the Esterline-CMC Electronics Company in its goals to improve the Flight Management System FMS. In this model implemented in FLSIM by CMC-Electronics Esterline, a longitudinal instability appears during the approach phase and when flaps have a higher or equal angle to 4 degrees. The global project at LARCASE consisted in the improvement of the L1011-500 aerodynamic model stability under Matlab / Simulink and mainly for flaps angles situated between 4 degrees and 22 degrees. The L1011-500 global model was finalized in order to visualize and analyze its dynamic behavior. When the global model of the aircraft L1011-500 was generated, corrections were added to the lift coefficient (CL), the drag coefficient (CD) and the pitching moment coefficient (CM) to ensure the trim of the aircraft. The obtained results are compared with the flight tests data delivered by CMC Electronics-Esterline to validate our numerical studies.

  2. Biologie des populations des Monogènes Polystomatidae

    Directory of Open Access Journals (Sweden)

    TINSLEY R. C.

    1993-01-01

    Full Text Available Les cycles des monogènes polystomatidae montrent une très grande diversité. Parmi ceux qui infestent des amphibiens anoures, on devrait s'attendre à ce que la taille des populations parasites montre des différences prononcées, selon que des réinfestations interviennent régulièrement chaque année, ou qu'il n'y en ait qu'une dans la vie de l'hôte. Toutefois, à quelques exceptions près, les niveaux d'infestation sont généralement bas, quelle que soit la durée de vie de l'hôte. Les facteurs susceptibles de réguler les populations de polystomatidae parasites d'amphibiens anoures sont récapitulés ici, et nous nous penchons plus particulièrement sur les mécanismes contrôlant l'infestation et, par voie de conséquence, la survie post-infestation. Les effets d'un éventail de facteurs sont envisagés, parmi lesquels les contraintes environnementales externes (en particulier, la température, les facteurs liés à l'hôte (dont le comportement et la durée de vie et les facteurs propres au parasite (dont la compétition intraspécifique. Deux genres de Polystomatidae témoignent d'une régulation densité-dépendante des infrapopulations unique, contrôlée par la production de deux types de larves. Il existe des données de terrain et de laboratoire qui permettent de quantifier les effets de ces différents paramètres pour un certain nombre d'espèces de Polystomes. Les résultats obtenus pour Pseudodiplorchis americanus suggèrent que, même lorsqu'ils sont combinés, les effets de ces différents facteurs ne suffisent pas à rendre compte de la puissante régulation que l'on observe dans les populations naturelles où, malgré de massives infestations annuelles, les populations de parasites adultes sont faibles en effectif et remarquablement stables d'une année à l'autre. C'est la preuve indirecte qu'une importante régulation intervient par l'intermédiaire de l'immunité-hôte. Pour pouvoir pousser plus loin l

  3. Osteoporose und Genetik des Knochenstoffwechsels

    Directory of Open Access Journals (Sweden)

    Obermayer-Pietsch B

    2002-01-01

    Full Text Available Osteoporose ist in hohem Maß genetisch determiniert. Neue Wege der molekularbiologischen Forschung haben sich in den letzten Jahren auf diesem Gebiet etabliert. "Gene mapping" mit polymorphen genetischen Markern auf der Suche nach Phänotyp-assoziierten Genen ist ein aufwendiges, aber vielversprechendes Verfahren und wird durch die Erkenntnisse des Human Genome Projects beschleunigt. So wurde jüngst u. a. das Low-density Lipoprotein 5-Gen als wichtig für den Knochenstoffwechsel identifiziert. Kandidaten-gene wie Hormonrezeptor-, Cytokin- oder Kollagen-Gene werden hinsichtlich ihrer Gen-Gen- und Gen-Umwelt- Interaktionen untersucht und erlauben neue funktionelle Einsichten in Erkrankungen des Knochenstoffwechsels. Mutationen der Kollagen-Gene sind bei einigen seltenen Erkrankungen, wie dem Osteoporose-Pseudogliom-Syndrom oder der Osteogenesis imperfecta gefunden worden, könnten aber auch für häufige Varianten von Bindegewebsstörungen wie der congenitalen Hüftdysplasie verantwortlich sein, die etwa 10 % der weiblichen kaukasischen Bevölkerung in unterschiedlichem Ausmaß betrifft. Osteoporose am Schenkelhals und erhöhte Gelenkslaxizität sowie andere generalisierte Veränderungen des Knochen- und Kollagenstoffwechsels können hier möglicherweise ebenfalls durch Störungen des Kollagen I alpha 1-Gens erklärt werden. In Summe können wir zahlreiche neue Einsichten in die Pathophysiologie des Skelettsystems erwarten, die uns auch neue Zugangswege für Diagnostik und Therapie unserer Patienten ermöglichen werden.

  4. Contribution to the modeling and the identification of haptic interfaces; Contribution a la modelisation et a l'identification des interfaces haptiques

    Energy Technology Data Exchange (ETDEWEB)

    Janot, A

    2007-12-15

    This thesis focuses on the modeling and the identification of haptic interfaces using cable drive. An haptic interface is a force feedback device, which enables its user to interact with a virtual world or a remote environment explored by a slave system. It aims at the matching between the forces and displacements given by the user and those applied to virtual world. Usually, haptic interfaces make use of a mechanical actuated structure whose distal link is equipped with a handle. When manipulating this handle to interact with explored world, the user feels the apparent mass, compliance and friction of the interface. This distortion introduced between the operator and the virtual world must be modeled and identified to enhance the design of the interface and develop appropriate control laws. The first approach has been to adapt the modeling and identification methods of rigid and localized flexibilities robots to haptic interfaces. The identification technique makes use of the inverse dynamic model and the linear least squares with the measurements of joint torques and positions. This approach is validated on a single degree of freedom and a three degree of freedom haptic devices. A new identification method needing only torque data is proposed. It is based on a closed loop simulation using the direct dynamic model. The optimal parameters minimize the 2 norms of the error between the actual torque and the simulated torque assuming the same control law and the same tracking trajectory. This non linear least squares problem dramatically is simplified using the inverse model to calculate the simulated torque. This method is validated on the single degree of freedom haptic device and the SCARA robot. (author)

  5. Discrete kinematic modeling of the 3-D deformation of sedimentary basins; Modelisation cinematique discrete de la deformation 3D des bassins sedimentaires

    Energy Technology Data Exchange (ETDEWEB)

    Cornu, T.

    2001-01-01

    The present work deals with three-dimensional deformation of sedimentary basins. The main goal of the work was to propose new ways to study tectonic deformation and to insert it into basin-modeling environment for hydrocarbon migration applications. To handle the complexity of the deformation, the model uses kinematic laws, a discrete approach, and the construction of a code that allows the greatest diversity in the deformation mechanisms we can take into account. The 3-D-volume deformation is obtained through the calculation of the behavior of the neutral surface of each basin layer. The main idea is to deform the neutral surface of each layer with the help of geometrical laws and to use the result to rebuild the volume deformation of the basin. The constitutive algorithm includes three characteristic features. The first one deals with the mathematical operator we use to describe the flexural-slip mechanism which is a combination of the translation of the neutral surface nodes and the rotation of the vertical edges attached to these nodes. This performs the reversibility that was required for the basin modeling. The second one is about. the use of a discrete approach, which gives a better description of the global deformation and offers to locally control volume evolutions. The knowledge of volume variations can become a powerful tool in structural geology analysis and the perfect complement for a field study. The last one concerns the modularity of the developed code. Indeed, the proposed model uses three main mechanisms of deformation. But the architecture of the code allows the insertion of new mechanisms or a better interaction between them. The model has been validated first with 2-D cases, then with 3-D natural cases. They give good results from a qualitative point of view. They also show the capacity of the model to provide a deformation path that is geologically acceptable, and its ability to control the volume variations of the basin through the

  6. Report of the seminar modeling of pollutants emissions by road transport; Compte-rendu du seminaire modelisation des emissions de polluants par le transport routier

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This seminar was organised by A.D.E.M.E. around the following themes: uncertainties and sensitivity analysis of the C.O.P.E.R.T. 3 model (computer programme to calculate emissions from road transport), presentation of studies using the C.O.P.E.R.T. 3 model for the estimation of road transport emissions, the future of the modeling of transport emissions from C.O.P.E.R.T.3 to A.R.T.E.M.I.S. (assessment and reliability of transport emission models and inventory systems). The interventions were as follow: uncertainties and sensitivity analysis of the C.O.P.E.R.T. 3 model, emissions from road transport in the E.S.C.O.M.P.T.E. programme (study of sensitivity), analysis of sensitivity at the level of temporal aggregation of the spatialized traffic (to evaluate the sensitivity of an inventory at the level of temporal aggregation of traffic data on an important geographic area) application in the case of the I.N.T.E.R.R.E.G. project (Alsace), the road transport part of the regional plan for air quality in Bourgogne taking into account the road network, intercomparison of tools and inventory methods of road transport emissions, evolution of the French automobile park until 2005 and new projections, application of C.O.P.E.R.T. 3 to the French context a new version of I.M.P.A.C.T.- A.D.E.M.E., the European project A.R.T.E.M.I.S. structures novelties considered for the road transport emissions modeling. (N.C.)

  7. Tirer parti des données massives des réseaux mobiles pour établir ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Tirer parti des données massives des réseaux mobiles pour établir des politiques de développement. Nombre de pays en développement sont dépourvus des capacités et des ressources requises pour recueillir et analyser des données aux fins de l'élaboration de politiques basées sur des données probantes.

  8. Pilot study on diffusive ground heat storage in the SUVA 'D4' building complex in Root, Switzerland; Etude pilote pour le stockage diffusif des batiments du centre D4 de la SUVA a Root, Lucerne. Analyse de 2 tests de reponse geothermique et integration du stockage diffusif dans le systeme

    Energy Technology Data Exchange (ETDEWEB)

    Pahud, D.

    2001-07-01

    This report for the Swiss Federal Office of Energy (SFOE) presents, in a first part, the results of two thermal response tests made on a geothermal heat storage system that forms part of a heating and cooling system for a complex of buildings comprising the 'D4' centre of the Swiss Accident Insurance Institution (SUVA) in Root, near Lucerne, Switzerland. These in situ response tests on two borehole heat exchangers confirmed the laboratory measurements, indicating that no significant ground water flow is present. In a second part the heat storage dimensioning and the heating/cooling system evaluation by means of computerized simulation are described, which used simulated data for the heating and cooling requirements of the new buildings and the ground heat storage parameters. The PILESIM thermal simulation tool is described, a computer code used to simulate heating and cooling systems that use heat-exchanger piles or borehole heat exchangers. The evaluations made on three system concepts are discussed that permitted the optimal design of the diffusive ground storage system. The construction of the actual system is also described.

  9. R and D levers for an abatement of industrial CO{sub 2} emissions by 2030 in the building industry sector; Leviers R and D pour une reduction des emissions industrielles de CO{sub 2} a l'echeance de 2030 dans le secteur du batiment

    Energy Technology Data Exchange (ETDEWEB)

    Capmas, A.

    2006-03-15

    This document presents in a series of transparencies: the regulatory framework of CO{sub 2} emissions (Kyoto protocol, CO{sub 2} trading market), the CO{sub 2} emissions in the cement industry and the actions implemented to limit them (energy conservation, fuel substitution, recycling of by-products from other industries), the life cycle analysis in the building industry (construction stage and entire life of the building), the energy saving potentialities in existing buildings (double-glazing, mineral wools, space heating system, thermal inertia, insulation etc..), the use of the thermal inertia of concrete and cement to save energy, and some examples of implementation in municipal buildings. (J.S.)

  10. Building envelope design for renewal of air by natural ventilation in moderate climates. Proposition of a designing methodology; Conception des enveloppes de batiments pour le renouvellement d'air par ventilation naturelle en climats temperes. Proposition d'une methodologie de conception

    Energy Technology Data Exchange (ETDEWEB)

    Mansouri, Y.

    2003-12-01

    The subject of this research is to produce methods and methodological tools for the architects to support the integration of natural ventilation systems in the building envelope design. Our research is situated to the interface between the architectural practice and the physical research on natural ventilation. We are interested in phenomena that can influence or force the strategy of ventilation. A morphological analysis of naturally ventilated buildings concerning the integration modes of natural ventilation systems is done permitting US to propose a typology and a topology of ventilation systems. We define criteria in relation to the thermal comfort, to the quality of air and the economy of energy to assess air renewal techniques. In complement of the sizing tool, we elaborate a methodology of conception for the integration of passives ventilation systems. Design guidelines permit US to conclude on an effective natural ventilation system which is well adapted to collective habitat. (author)

  11. Radiative modeling and characterization of aerosol plumes hyper-spectral imagery; Modelisation radiative et caracterisation des panaches d'aerosols en imagerie hyperspectrale

    Energy Technology Data Exchange (ETDEWEB)

    Alakian, A

    2008-03-15

    This thesis aims at characterizing aerosols from plumes (biomass burning, industrial discharges, etc.) with hyper-spectral imagery. We want to estimate the optical properties of emitted particles and also their micro-physical properties such as number, size distribution and composition. To reach our goal, we have built a forward semi-analytical model, named APOM (Aerosol Plume Optical Model), which allows to simulate the radiative effects of aerosol plumes in the spectral range [0,4-2,5 {mu}m] for nadir viewing sensors. Mathematical formulation and model coefficients are obtained from simulations performed with the radiative transfer code COMANCHE. APOM is assessed on simulated data and proves to be accurate with modeling errors between 1% and 3%. Three retrieval methods using APOM have been developed: L-APOM, M-APOM and A-APOM. These methods take advantage of spectral and spatial dimensions in hyper-spectral images. L-APOM and M-APOM assume a priori knowledge on particles but can estimate their optical and micro-physical properties. Their performances on simulated data are quite promising. A-APOM method does not require any a priori knowledge on particles but only estimates their optical properties. However, it still needs improvements before being usable. On real images, inversion provides satisfactory results for plumes above water but meets some difficulties for plumes above vegetation, which underlines some possibilities of improvement for the retrieval algorithm. (author)

  12. Kinetic modelling of hydro-treatment reactions by study of different chemical groups; Modelisation cinetique des reactions d`hydrotraitement par regroupement en familles chimiques

    Energy Technology Data Exchange (ETDEWEB)

    Bonnardot, J.

    1998-11-19

    Hydro-treatment of petroleum shortcuts permits elimination of unwanted components in order to increase combustion in engine and to decrease atmospheric pollution. Hydro-desulfurization (HDS), Hydro-denitrogenation (HDN) and Hydrogenation of aromatics (HDA) of a LCO (Light Cycle Oil)-Type gas oil have been studied using a new pilot at a fixed temperature with a NiMo/Al{sub 2}O{sub 3} catalyst. A hydrodynamic study showed that reactions occurring in the up-flow fixed bed reactor that has been used during the experiments, were governed exclusively by chemical reaction rates and not by diffusion. Through detailed chemical analysis, height chemical groups have been considered: three aromatics groups, one sulfided group, one nitrogenized and NH{sub 3}, H{sub 2}S, H{sub 2}. Two Langmuir-Hinshelwood-type kinetic models with either one or two types of sites have been established. The model with two types of site - one site of hydrogenation and one site of hydrogenolysis - showed a better fit in the modeling of the experimental results. This model enables to forecast the influence of partial pressure of H{sub 2}S and partial pressure of H{sub 2} on hydro-treatment reactions of a LCO-type gas oil. (author) 119 refs.

  13. Etats des lieux des e-services internes dans les organisations

    OpenAIRE

    Orru, Fiona

    2017-01-01

    A l’heure actuelle, les techniques de communication interne ont évoluées. Au fil des années, la communication passe des outils dit classiques vers une communication de plus en plus orientée vers des outils virtuels et informatisés tels que l’internet, l’intranet, les réseaux sociaux, … Ce mémoire consistait à faire un « Etat des lieux des e-services internes existants dans les organisations ». La recherche de ce travail, soutenue par une étude quantitative, a permis d’analyser l’impact des e-...

  14. Estimation et validation des derivees de stabilite et controle du modele dynamique non-lineaire d'un drone a voilure fixe

    Science.gov (United States)

    Courchesne, Samuel

    Knowledge of the dynamic characteristics of a fixed-wing UAV is necessary to design flight control laws and to conceive a high quality flight simulator. The basic features of a flight mechanic model include the properties of mass, inertia and major aerodynamic terms. They respond to a complex process involving various numerical analysis techniques and experimental procedures. This thesis focuses on the analysis of estimation techniques applied to estimate problems of stability and control derivatives from flight test data provided by an experimental UAV. To achieve this objective, a modern identification methodology (Quad-M) is used to coordinate the processing tasks from multidisciplinary fields, such as parameter estimation modeling, instrumentation, the definition of flight maneuvers and validation. The system under study is a non-linear model with six degrees of freedom with a linear aerodynamic model. The time domain techniques are used for identification of the drone. The first technique, the equation error method is used to determine the structure of the aerodynamic model. Thereafter, the output error method and filter error method are used to estimate the aerodynamic coefficients values. The Matlab scripts for estimating the parameters obtained from the American Institute of Aeronautics and Astronautics (AIAA) are used and modified as necessary to achieve the desired results. A commendable effort in this part of research is devoted to the design of experiments. This includes an awareness of the system data acquisition onboard and the definition of flight maneuvers. The flight tests were conducted under stable flight conditions and with low atmospheric disturbance. Nevertheless, the identification results showed that the filter error method is most effective for estimating the parameters of the drone due to the presence of process noise and measurement. The aerodynamic coefficients are validated using a numerical analysis of the vortex method. In addition, a

  15. Évaluation de la valeur nutritive et recherche des substances ...

    African Journals Online (AJOL)

    SARAH

    30 juin 2016 ... et des lipides. Puis, l'évaluation a été effectuée sur ces échantillons pour rechercher la présence des alcaloïdes, des saponines, des quinones, des stéroïdes, des terpenoïdes, des flavonoïdes, des leucoanthocyanes, des tannoïdes et des hétérosides cyanogénétiques. Les teneurs moyennes en humidité ...

  16. Multistatic Surveillance and Reconnaissance: Sensor, Signals and Data Fusion (Surveillance et Reconnaissance Multistatiques : Fusion des capteurs, des signaux et des donnees)

    Science.gov (United States)

    2009-04-01

    capteurs , des signaux et des données) Research and Technology Organisation (NATO) BP 25, F-92201 Neuilly-sur-Seine Cedex, France RTO-EN-SET-133...Multistatiques : Fusion des capteurs , des signaux et des données) The material in this publication was assembled to support a Lecture Series under the...Surveillance et Reconnaissance Multistatiques : Fusion des capteurs , des signaux et des données (RTO-EN-SET-133) Synthèse Les systèmes radar

  17. La territorialisation des politiques environnementales

    Directory of Open Access Journals (Sweden)

    Amédée Mollard

    2010-10-01

    Full Text Available Le point de départ de cet article est la grande variabilité de la pollution nitrique diffuse de l’eau due à l’agriculture. Celle-ci dépend en particulier du climat, des types de sol et des systèmes de production agricole. Nos recherches réalisées de façon interdisciplinaire à partir de deux sites différents en France, montrent que cette hétérogénéité spatio-temporelle conditionne les pratiques agricoles mises en œuvre pour réduire la pollution au niveau de la norme admise. De ce fait, les pratiques les plus « coût-efficaces » diffèrent d’un territoire à l’autre, en fonction des caractéristiques locales. Ces résultats mettent donc en évidence une efficacité potentielle d’une territorialisation des politiques publiques. En théorie, de telles politiques sont considérées comme optimales par les économistes, car elles incitent les agents à moduler leurs efforts en fonction de la sensibilité du milieu. Mais, selon les études empiriques, cet avantage serait annulé par un coût élevé de mise en œuvre, de contrôle et de surveillance. Pour maintenir leur avantage sur des politiques uniformes, les politiques territorialisées devraient être mises en œuvre à un niveau spatial optimal. Un tel niveau devrait au minimum atteindre un compromis entre l’économie réalisée grâce à une modulation adaptée aux conditions locales et les sur-coûts dus à la décentralisation des solutions mises en œuvre. Cet article analyse la pertinence d’une prise en compte de ces spécificités par des politiques territorialisées. L’efficacité d’une régulation différenciée de la pollution nitrique est étudiée ici en évaluant l’importance de la variabilité spatiale des paramètres physiques et des coûts de la territorialisation.The paper starts with the wide variability of nonpoint water nitrogenous pollution generated by agriculture. This variability depends especially on climate, soil types and farming

  18. Kinetic modeling of the thermal evolution of crude oils in sedimentary basins; Modelisation cinetique de l'evolution thermique des petroles dans les gisements

    Energy Technology Data Exchange (ETDEWEB)

    Bounaceur, R.

    2001-01-15

    The aim of this work is to obtain a better understanding of the reactions involved in the thermal cracking of crude oil in sedimentary basins, and to study its kinetics as a function of temperature and pressure. We study the kinetics of pyrolysis of alkanes at low temperature, high pressure and high conversion and we propose three methods of reduction of the corresponding mechanisms. Several compounds having an inhibiting or accelerating effect on the rate of decomposition of alkanes were also studied. This research led to the construction of a general kinetic model of 5200 elementary steps representing the pyrolysis of a complex mixture of 52 molecules belonging to various chemical families: 30 linear alkanes (from CH{sub 4} to C{sub 30}H{sub 62}), 10 branched-chain alkanes (including pristane and phytane), 2 naphthenes (propyl-cyclo-pentane and propyl-cyclohexane), tetralin, 1-methyl-indan, 4 aromatics (benzene, toluene, butyl-benzene and decyl-benzene), 3 hetero-atomic compounds (a disulfide, a mercaptan and H{sub 2}S). This model is compared to experimental data coming from the pyrolysis of two oils: one from the North Sea and the other from Pematang. The results obtained show a good agreement between the experimental and simulated values. Then, we simulated the cracking of these two oils by using the following burial scenario: initial temperature of 160 degrees, 50 m per million years (ma) in a constant geothermal gradient of 30 degrees C/km, implying a heating rate of 1.5 degrees C/ma. Under these conditions, our model shows that these two oils start to crack only towards 210-220 degrees C and that their time of half-life corresponds to a temperature around 230-240 degrees C. The model also makes it possible to simulate the evolution of geochemical parameters such as the GOR, the API degree... (author)

  19. Contribution to modeling and dynamic risk hedging in energy markets; Contribution a la modelisation et a la gestion dynamique du risque des marches de l'energie

    Energy Technology Data Exchange (ETDEWEB)

    Noufel, Frikha

    2010-12-15

    This thesis is concerned with probabilistic numerical problems about modeling, risk control and risk hedging motivated by applications to energy markets. The main tool is based on stochastic approximation and simulation methods. This thesis consists of three parts. The first one is devoted to the computation of two risk measures of the portfolio loss distribution L: the Value-at-Risk (VaR) and the Conditional Value-at-Risk (CVaR). This computation uses a stochastic algorithm combined with an adaptive variance reduction technique. The first part of this chapter deals with the finite dimensional case, the second part extends the results of the first part to the case of a path-dependency process and the last one deals low discrepancy sequences. The second chapter is devoted with risk minimizing hedging strategies in an incomplete market operating in discrete time using quantization based stochastic approximation. Theoretical results on CVaR hedging are presented then numerical aspects are addressed in a Markovian framework. The last part deals with joint modeling of Gas and Electricity spot prices. The multi-factor model presented is based on stationary Ornstein process with parameterized diffusion coefficient. (author)

  20. 3-D modeling of parietal liquid films in internal combustion engines; Modelisation tridimensionnelle des films liquides parietaux dans les moteurs a combustion interne

    Energy Technology Data Exchange (ETDEWEB)

    Foucart, H.

    1998-12-11

    To simulate the air-fuel mixing in the intake ports and cylinder of an internal combustion engines, a wall fuel liquid film model has been developed for integration in 3D CFD codes. Phenomena taken into account include wall film formation by an impinging spray without splashing effect, film transport such as governed by mass and momentum equations with hot wall effects, and evaporation considering energy equation with an analytical mass transfer formulation developed here. A continuous-fluid method is used to describe the wall film over a three dimensional complex surface. The basic approximation is that of a laminar incompressible boundary layer; the liquid film equations are written in an integral form and solved by a first-order ALE finite volume scheme; the equation system is closed without coefficient fitting requirements. The model has been implemented in a Multi-Block version of KIVA-II (KMB) and tested against problems having theoretical solutions. Then in a first step, it has been compared to the measurements obtained in a cylindrical pipe reproducing the main characteristics of SI engine intake pipe flow and in a second step, it has been compared to the Xiong experiment concerning the film evaporation on a hot wall. The film behaviour is satisfactory reproduced by the computations for a set of operating conditions. Finally, engine calculations were conducted showing the importance of including a liquid film model for the simulations. (author) 54 refs.

  1. Proposal of a numerical modeling of reactive flows in combustion chambers of turbojet engines; Proposition d`une modelisation numerique des ecoulements reactifs dans les foyers de turboreacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Ravet, F. [Rouen Univ., 76 - Mont-Saint-Aignan (France)]|[SNECMA, 77 - Moissy-Cramayel (France); Baudoin, Ch.; Schultz, J.L. [SNECMA, 77 - Moissy-Cramayel (France)

    1996-12-31

    Simplifying hypotheses are required when combustion and aerodynamic phenomena are considered simultaneously. In this paper, a turbulent combustion model is proposed, in which the combustion chemistry is reduced to a single reaction. In this way, only two variables are needed to describe the problem and combustion can be characterized by the consumption of one of the two reactive species. In a first step, the instantaneous consumption rate is obtained using the Lagrangian form of the mass fraction equation of the species under consideration, and by considering the equilibrium state only. This state is determined in order to preserve the consistency with results that should be obtained using a complete kinetics scheme. In a second step, the average rate is determined using the instantaneous consumption term and a probabilistic density function. This model was tested on various configurations and in particular on an experimental main chamber and on a reheating chamber. Results indicate that this model could be used to predict temperature levels inside these combustion chambers. Other applications, like the prediction of pollutant species emission can be considered. (J.S.) 12 refs.

  2. Modelling and numerical simulation of liquid-vapor phase transitions; Modelisation et simulation numerique des transitions de phase liquide-vapeur

    Energy Technology Data Exchange (ETDEWEB)

    Caro, F

    2004-11-15

    This work deals with the modelling and numerical simulation of liquid-vapor phase transition phenomena. The study is divided into two part: first we investigate phase transition phenomena with a Van Der Waals equation of state (non monotonic equation of state), then we adopt an alternative approach with two equations of state. In the first part, we study the classical viscous criteria for selecting weak solutions of the system used when the equation of state is non monotonic. Those criteria do not select physical solutions and therefore we focus a more recent criterion: the visco-capillary criterion. We use this criterion to exactly solve the Riemann problem (which imposes solving an algebraic scalar non linear equation). Unfortunately, this step is quite costly in term of CPU which prevent from using this method as a ground for building Godunov solvers. That is why we propose an alternative approach two equations of state. Using the least action principle, we propose a phase changing two-phase flow model which is based on the second thermodynamic principle. We shall then describe two equilibrium submodels issued from the relaxations processes when instantaneous equilibrium is assumed. Despite the weak hyperbolicity of the last sub-model, we propose stable numerical schemes based on a two-step strategy involving a convective step followed by a relaxation step. We show the ability of the system to simulate vapor bubbles nucleation. (author)

  3. Experimental approach and micro-mechanical modeling of the mechanical behavior of irradiated zirconium alloys; Approche experimentale et modelisation micromecanique du comportement des alliages de zirconium irradies

    Energy Technology Data Exchange (ETDEWEB)

    Onimus, F

    2003-12-01

    Zirconium alloys cladding tubes containing nuclear fuel of the Pressurized Water Reactors constitute the first safety barrier against the dissemination of radioactive elements. Thus, it is essential to predict the mechanical behavior of the material in-reactor conditions. This study aims, on the one hand, to identify and characterize the mechanisms of the plastic deformation of irradiated zirconium alloys and, on the other hand, to propose a micro-mechanical modeling based on these mechanisms. The experimental analysis shows that, for the irradiated material, the plastic deformation occurs by dislocation channeling. For transverse tensile test and internal pressure test this channeling occurs in the basal planes. However, for axial tensile test, the study revealed that the plastic deformation also occurs by channeling but in the prismatic and pyramidal planes. In addition, the study of the macroscopic mechanical behavior, compared to the deformation mechanisms observed by TEM, suggested that the internal stress is higher in the case of irradiated material than in the case of non-irradiated material, because of the very heterogeneous character of the plastic deformation. This analysis led to a coherent interpretation of the mechanical behavior of irradiated materials, in terms of deformation mechanisms. The mechanical behavior of irradiated materials was finally modeled by applying homogenization methods for heterogeneous materials. This model is able to reproduce adequately the mechanical behavior of the irradiated material, in agreement with the TEM observations. (author)

  4. Géographie des interfaces. Une nouvelle vision des territoires

    Directory of Open Access Journals (Sweden)

    Marie Redon

    2011-07-01

    Full Text Available Littéralement, une interface est une surface de séparation entre deux états distincts de la matière. Le terme, ayant cheminé de la physique à la biologie, et aussi désormais d’usage répandu en informatique. En géographie, l’usage du mot s’est développé dans les années 1980 et peut être défini comme un espace permettant la mise en relation de deux espaces/territoires différents, influencé par des échanges entre l’un et l’autre, et se distinguant par là-même des deux espaces contigus. Intégrant...

  5. Enquête de satisfaction des restaurants

    CERN Multimedia

    Staff Association

    2016-01-01

    Comité de surveillance des restaurants L’Association du personnel est représentée dans plusieurs comités dont le Comité de surveillance des restaurants (CSR) qui a pour mandat : de donner son avis sur toute question relative à la politique générale de l’Organisation en matière de restauration sur le site, y compris en ce qui concerne les termes et l’attribution des contrats d’exploitation des restaurants ; de définir dans le cadre des contrats d’exploitation des restaurants, les prestations correspondant aux besoins et, dans la mesure du possible, aux désirs du personnel ; de surveiller les prestations des restaurants, y compris en ce qui concerne la qualité et la préparation des produits ; de négocier avec les concessionnaires des restaurants au sujet des tarifs et de surveill...

  6. Administration et gestion des contrats XL

    CERN Document Server

    Senouf, J

    2000-01-01

    Les grands contrats de travaux génèrent un grand nombre de commandes (OSVC) passées par un grand nombre de responsables techniques. Ils sont généralement basés sur des bordereaux de prix associés à un éventail de conditions économiques adaptées aux besoins complexes et variés des multiples utilisateurs du CERN nécessitant des calculs sophistiqués. L'administration des commandes, le suivi des travaux et de la facturation doivent répondre aux besoins de tous les acteurs. Les responsables techniques doivent jouir de la plus large indépendance administrative dans le respect des règlements CERN et des conditions contractuelles. Le contrôle des métrés et décomptes doit être rigoureux et d'une traçabilité complète. L'utilisation des bases de données Oracle a déjà permis l'intégration des données administratives et techniques. Le Web nous invite à une communication totale et transparente entre les utilisateurs, les services techniques et les contractants. De nouveaux types de contrat so...

  7. Simulation de la formabilite des alliages d'aluminium AA5754 et AA6063

    Science.gov (United States)

    Eljaafari, Samira

    Les besoins de reduction du poids se sont concretement traduits par l'introduction de nouvelles nuances plus legeres dans les structures automobiles. Ainsi, des alliages d'aluminium ont commence a etre integres dans les pieces de structure de plusieurs vehicules. La faible masse volumique des alliages d'aluminium (2,7g/cm3) permet d'alleger le poids du vehicule qui entraine une diminution de la consommation de carburant et, donc, des emissions de gaz a effet de serre. La striction et la rupture sont les principaux modes de defaillance qui entrainent le rebut systematique des pieces. C'est pourquoi, ameliorer la prediction d'apparition de ces defauts lors de la simulation va dans le sens d'une meilleure maitrise du procede. Dans le cadre de ce travail doctoral, deux modeles sont developpes pour simuler le comportement a grandes deformations d'alliages d'aluminium: un modele polycristallin de type Taylor et un modele a un ou plusieurs elements finis par grain. Les diagrammes limites de formage (DLF) pour les deux alliages d'aluminium AA5754 et AA6063 ont ete simules numeriquement en utilisant une formulation par elements finis pour les polycristaux basee sur l'hypothese de Taylor. Les DLF conventionnels et de l'hydroformage ont ete traces. L'effet des chemins de deformation sur la formabilite des alliages d'aluminium a aussi ete etudie. Finalement, des simulations numeriques avec les donnees de diffraction des electrons retrodiffuses (EBSD) pour 1'alliage d'aluminium AA5754 ont ete effectuees en utilisant le modele a un ou plusieurs elements par grain. Ces simulations sont executees avec differents modeles du durcissement (Asaro, Bassani et puissance). Mots-cles: Formabilite; Alliage d'aluminium; Hydroformage; Glissement cristallographique; Durcissement; Calcul parallele; Diagramme limite de formage (DLF); Diffraction electron.

  8. Regroupement des statistiques sur le secteur des TIC et analyse ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    La présence et l'influence des technologies de l'information et de la communication (TIC) continuent de s'élargir et de s'accroître, tout comme leurs répercussions sur le développement économique. Toutefois, il reste encore beaucoup de travail à faire avant de pouvoir comprendre d'une manière systématique et ...

  9. Analyse des caractéristiques structurelles et des performances ...

    African Journals Online (AJOL)

    SARAH

    28 févr. 2014 ... 4p. Depieu ME, Doumbia S, Keli ZJ et Zouzou M, 2010. Typologie des exploitations en riziculture de la région de Saïoua, en zone forestière de la Côte d'Ivoire. Journal of Applied Biosciences. 35 :2301-2309. Doumbia, S et Depieu, M.E. 2013. Perception paysanne du changement climatique et stratégies.

  10. Planification optimisee des reseaux electriques par la methode des ...

    African Journals Online (AJOL)

    L'objectif principal de cette planification est l'optimisation des coûts de production de ces sources d'énergie électrique renouvelables et de transit de puissance dans les lignes du réseau lors de leur insertion dans le réseau électrique en tenant compte de la quantité maximale de tonne de CO2 évitée pour la protection de ...

  11. Étude cytogenetique des aberrations chromosomiques chez des ...

    African Journals Online (AJOL)

    Ces techniciens et volontaires témoins ont été soumis à l'épreuve de prélèvement de 5 ml de sang veineux au pli du coude dans des tubes d'héparine sodique. Après 48 ... These technicians and Volunteers (controls) were subjected to the test sample of 5 ml of venous blood to the elbow crease in sodium heparin tubes.

  12. Comportement des polluants des eaux pluviales urbaines en ...

    African Journals Online (AJOL)

    échange de l'oxygène de l'air avec les eaux usées [20]. 5. CONCLUSION. Ce travail a pour objectif d'évaluer le degré de dégradation de la pollution des eaux usées dans différents milieux (naturel, artificiel et semi naturel) en période humide.

  13. Prevision des ventes et efficacite des chaines logistiques - Essai de ...

    African Journals Online (AJOL)

    L'application de ces méthodes se fera dans une entreprise algérienne (la laiterie de RIO) spécialisée dans la production du yaourt. On étudiera les caractéristiques de la production et on estimera les ventes hebdomadaires en utilisant la méthode de Box et Jenkins. La modélisation des chaines logistiques se fera grâce à la ...

  14. DES EFFETS DURABLES DES VIES TRANSFORMÉES

    International Development Research Centre (IDRC) Digital Library (Canada)

    Son but est simple : veiller à ce que les personnes les plus vulnérables dans le monde, en particulier ... Simple et pourtant très efficace, le filtre biosable fournit de l'eau potable dans plus de 300 000 foyers de par le ... de rétablir la fertilité des sols dégradés par l'extraction de l'argile nécessaire à la fabrication de briques, ...

  15. Influence du mode de pollinisation et des caracteristiques des fruits ...

    African Journals Online (AJOL)

    La graine est l'organe principal de propagation du papayer (Carica papaya), chez qui les problèmes de germination sont récurrents. L'influence du mode de pollinisation et de la conservation des papayes sur la qualité de leurs semences est étudiée. Six cents fleurs hermaphrodites, de la lignée Solo n°8, sont marquées au ...

  16. Etudes des mecanismes de dissolution des phosphates naturels de ...

    African Journals Online (AJOL)

    Dans le cadre de la recherche sur la dissolution du phosphate calcique apatitique, une étude du mécanisme de cette dissolution basé sur la complexation des ions métalliques du minerai par deux acides humiques extraits d'un sol (AHS) et d'un compost (AHC) a été réalisée. L'ion calcium (Ca2+), ion majoritaire dans les ...

  17. Mesoscale modeling of the production and the three-dimensional transport of nitrogen oxides in thunderstorms; Mesoskalige Modellierung der Produktion und des dreidimensionalen Transports von Stickoxiden durch Gewitter

    Energy Technology Data Exchange (ETDEWEB)

    Fehr, T.

    2000-07-01

    Nitrogen oxides, NO{sub x} = NO + NO{sub 2}, play a fundamental role in tropospheric chemistry. Compared to other sources, the contribution of lightning induced NO{sub x} (LNO{sub x}) is known with considerable uncertainties and difficult to determine experimentally. The distribution of nitrogen oxides in an isolated thunderstorm is investigated using a modified version of the Penn State/NCAR Mesoscale Model (MM5) with cloud-scale resolution. A Lagrangian particle model has been developed to represent the NO{sub x} released by individual flashes. The position of the flash, the flash type, the geometrical properties of the channel, and the amount of emitted NO{sub x} are introduced to the MM5 in a parameterized form. On July 21, 1998, during the European lightning nitrogen oxides project (EULINOX) field campaign, a supercell development was observed in the German alpine foreland. Anvil penetrations by the DLR Falcon aircraft contributed high resolution profiles of NO{sub x}. DLR radar observation covered the complete life cycle of the thunderstorm. The lightning activity was recorded with a lightning positioning and tracking system (LPATS) run by local power suppliers, while radiosonde and aircraft measurements supplied detailed information on the atmospheric stratification ahead of the thunderstorm. This meteorological information was used to initalize a cloud-scale MM5 simulation. The modeled thunderstorm reproduces many observed properties, e.g. cell splitting, propagation speed and direction, anvil and overshooting top height, and WER (weak echo region). The number of simulated cloud-to-ground flashes, as well as the temporal evolution of the lightning activity are comparable to the LPAT observations. The general transport properties of the model thunderstorm are investigated using an inert PBL-tracer, as well as trajectory analysis. The simulated lightning activity leads to the release of approximately 1 000 000 NO{sub x}-particles. The thunderstorm produces 28

  18. Thermo-mechanical behaviour modelling of particle fuels using a multi-scale approach; Modelisation du comportement thermomecanique des combustibles a particules par une approche multi-echelle

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, V.

    2009-12-15

    Particle fuels are made of a few thousand spheres, one millimeter diameter large, compound of uranium oxide coated by confinement layers which are embedded in a graphite matrix to form the fuel element. The aim of this study is to develop a new simulation tool for thermo-mechanical behaviour of those fuels under radiations which is able to predict finely local loadings on the particles. We choose to use the square finite element method, in which two different discretization scales are used: a macroscopic homogeneous structure whose properties in each integration point are computed on a second heterogeneous microstructure, the Representative Volume Element (RVE). First part of this works is concerned by the definition of this RVE. A morphological indicator based in the minimal distance between spheres centers permit to select random sets of microstructures. The elastic macroscopic response of RVE, computed by finite element has been compared to an analytical model. Thermal and mechanical representativeness indicators of local loadings has been built from the particle failure modes. A statistical study of those criteria on a hundred of RVE showed the significance of choose a representative microstructure. In this perspective, a empirical model binding morphological indicator to mechanical indicator has been developed. Second part of the work deals with the two transition scale method which are based on the periodic homogenization. Considering a linear thermal problem with heat source in permanent condition, one showed that the heterogeneity of the heat source involve to use a second order method to localized finely the thermal field. The mechanical non-linear problem has been treats by using the iterative Cast3M algorithm, substituting to integration of the behavior law a finite element computation on the RVE. This algorithm has been validated, and coupled with thermal resolution in order to compute a radiation loading. A computation on a complete fuel element

  19. Creep and damage in argillaceous rocks: microstructural change and phenomenological modeling; Fluage et endommagement des roches argileuses: evolution de la microstructure et modelisation phenomenologique

    Energy Technology Data Exchange (ETDEWEB)

    Fabre, G

    2005-06-15

    The underground radioactive waste disposal far exceeds the period of exploitation of common civil engineering works. These specific projects require to predict the irreversible deformations over a large time scale (several centuries) in order to assess the extension and to forecast the evolution of the EDZ (Excavation Damage Zone) around the cavity. In this study, the viscosity of three sedimentary argillaceous rocks has been studied under different conditions of uniaxial compression: static or cyclic creep tests, monotonic and quasistatic tests, performed across various strata orientations. Argillaceous rocks are studied as a possible host layer for radioactive waste disposals. Indeed, they present some of the physical characteristics and mechanical properties, which are essential for being a natural barrier: low permeability, high creep potential and important holding capacity of radioactive elements. The purpose of the experimental study was to shed some light over the mechanisms governing the development of delayed deformations and damage of argillaceous rocks. It relates three rocks: an argillite from East of France, a Tournemire argillite and a marl from Jurassic Mountains. On atomic scale, viscoplastic deformations are due to irreversible displacements of crystalline defects, called dislocations. The experimental study was also supplemented with observations on thin sections extracted from the argillite and marl samples using a SEM. The aim was to identify the mechanisms responsible for the time-dependent behaviour on a microstructural scale. Analytical simulations of the mechanical behaviour of the three rocks gave parameters used in different viscoplastic models. The best modeling was obtained with the viscoplastic model which takes account of the development of volumetric strains and of the damage anisotropy. (author)

  20. Micromechanical simulation of Uranium dioxide polycrystalline aggregate behaviour under irradiation; Modele numerique micro-mecanique d'agregat polycristallin pour le comportement des combustibles oxydes

    Energy Technology Data Exchange (ETDEWEB)

    Pacull, J.

    2011-02-15

    In pressurized water nuclear power reactor (PWR), the fuel rod is made of dioxide of uranium (UO{sub 2}) pellet stacked in a metallic cladding. A multi scale and multi-physic approaches are needed for the simulation of fuel behavior under irradiation. The main phenomena to take into account are thermomechanical behavior of the fuel rod and chemical-physic behavior of the fission products. These last years one of the scientific issue to improve the simulation is to take into account the multi-physic coupling problem at the microscopic scale. The objective of this ph-D study is to contribute to this multi-scale approach. The present work concerns the micro-mechanical behavior of a polycrystalline aggregate of UO{sub 2}. Mean field and full field approaches are considered. For the former and the later a self consistent homogenization technique and a periodic Finite Element model base on the 3D Voronoi pattern are respectively used. Fuel visco-plasticity is introduced in the model at the scale of a single grain by taking into account specific dislocation slip systems of UO{sub 2}. A cohesive zone model has also been developed and implemented to simulate grain boundary sliding and intergranular crack opening. The effective homogenous behaviour of a Representative Volume Element (RVE) is fitted with experimental data coming from mechanical tests on a single pellet. Local behavior is also analyzed in order to evaluate the model capacity to assess micro-mechanical state. In particular, intra and inter granular stress gradient are discussed. A first validation of the local behavior assessment is proposed through the simulation of intergranular crack opening measured in a compressive creep test of a single fuel pellet. Concerning the impact of the microstructure on the fuel behavior under irradiation, a RVE simulation with a representative transient loading of a fuel rod during a power ramp test is achieved. The impact of local stress and strain heterogeneities on the multi

  1. A DES Procedure Applied to a Wall-Mounted Hump

    Directory of Open Access Journals (Sweden)

    Radoslav Bozinoski

    2012-01-01

    Full Text Available This paper describes a detached-eddy simulation (DES for the flow over a wall-mounted hump. The Reynolds number based on the hump chord is Rec=9.36×105 with an in-let Mach number of 0.1. Solutions of the three-dimensional Reynolds-averaged Navier-Stokes (RANS procedure are obtained using the Wilcox k−ω equations. The DES results are obtained using the model presented by Bush and Mani and are compared with RANS solutions and experimental data from NASA's 2004 Computational Fluid Dynamics Validation on Synthetic Jets and Turbulent Separation Control Workshop. The DES procedure exhibited a three-dimensional flow structure in the wake, with a 13.65% shorter mean separation region compared to RANS and a mean reattachment length that is in good agreement with experimental measurements. DES predictions of the pressure coefficient in the separation region also exhibit good agreement with experiment and are more accurate than RANS predictions.

  2. Characterisation, modelling and control of advanced scenarios in the european tokamak jet; Caracterisation, modelisation et controle des scenarios avances dans le tokamak europeen jet

    Energy Technology Data Exchange (ETDEWEB)

    Tresset, G

    2002-09-26

    The advanced scenarios, developed for less than ten years with the internal transport barriers and the control of current profile, give rise to a 'new deal' for the tokamak as a future thermonuclear controlled fusion reactor. The Joint European Torus (JET) in United Kingdom is presently the most powerful device in terms of fusion power and it has allowed to acquire a great experience in these improved confinement regimes. The reduction of turbulent transport, considered now as closely linked to the shape of current profile optimised for instance by lower hybrid current drive or the self-generated bootstrap current, can be characterised by a dimensionless criterion. Most of useful information related to the transport barriers are thus available. Large database analysis and real time plasma control are envisaged as attractive applications. The so-called 'S'-shaped transport models exhibit some interesting properties in fair agreement with the experiments, while the non-linear multivariate dependencies of thermal diffusivity can be approximated by a neural network, suggesting a new approach for transport investigation and modelling. Finally, the first experimental demonstrations of real time control of internal transport barriers and current profile have been performed on JET. Sophisticated feedback algorithms have been proposed and are being numerically tested to achieve steady-state and efficient plasmas. (author)

  3. Modelling of nuclear glasses by classical and ab initio molecular dynamics; Modelisation de verres intervenant dans le conditionnement des dechets radioactifs par dynamiques moleculaires classique et ab initio

    Energy Technology Data Exchange (ETDEWEB)

    Ganster, P

    2004-10-15

    A calcium aluminosilicate glass of molar composition 67 % SiO{sub 2} - 12 % Al{sub 2}O{sub 3} - 21 % CaO was modelled by classical and ab initio molecular dynamics. The size effect study in classical MD shows that the systems of 100 atoms are more ordered than the larger ones. These effects are mainly due to the 3-body terms in the empirical potentials. Nevertheless, these effects are small and the structures generated are in agreement with experimental data. In such kind of glass, we denote an aluminium avoidance and an excess of non bridging oxygens which can be compensated by tri coordinated oxygens. When the dynamics of systems of 100 and 200 atoms is followed by ab initio MD, some local arrangements occurs (bond length, angular distributions). Thus, more realistic vibrational properties are obtained in ab initio MD. The modelling of thin films shows that aluminium atoms extend to the most external part of the surface and they are all tri-coordinated. Calcium atoms are set in the sub layer part of the surface and they produce a depolymerization of the network. In classical MD, tri-coordinated aluminium atoms produce an important electric field above the surface. With non bridging oxygens, they constitute attractive sites for single water molecules. (author)

  4. Material characterization and non destructive testing by ultrasounds; modelling, simulation and experimental validation; Caracterisation des materiaux et controle non destructif par ultrasons; modelisation, simulation et validation experimentale

    Energy Technology Data Exchange (ETDEWEB)

    Noroy-Nadal, M.H

    2002-06-15

    This memory presents the research concerning the characterization of materials and the Non Destructive Testing (N.D.T) by ultrasonics. The different topics include three steps: modeling, computations and experimental validation. The studied materials concern mainly metals. The memory is divided in four parts. The first one concerns the characterization of materials versus temperature. The determination of the shear modulus G(T) is especially studied for a large temperature range, and around the melting point. The second part is devoted to studies by photothermal devices essentially focused on the modeling of the mechanical displacement and the stress field in coated materials. In this particular field of interest, applications concern either the mechanical characterization of the coating, the defect detection in the structure and finally the evaluation of the coating adhesion. The third section is dedicated to microstructural characterization using acoustic microscopy. The evaluation of crystallographic texture is especially approached, for metallic objects obtained by forming. Before concluding and pointing out some perspectives to this work, the last section concerns the introduction of optimization techniques, applied to the material characterization by acoustic microscopy. (author)

  5. Energy transition and security: which voluntary codes? Energy efficiency: IEA, IEC and ISO dialogue. The European Commission's safety, solidarity and efficiency measures. Securing natural gas supplies and favoring cogeneration. Less energy consuming buildings: rework of the energy efficiency directive. Energy efficiency inside buildings: GDF Suez report; Transition et securite energetiques: quels codes volontaires? Efficacite energetique: dialogue AIE, CEI et ISO. Les mesures de securite, solidarite et efficacite de la commission europeenne. Securiser l'approvisionnement en gaz naturel et favoriser la cogeneration. Des batiments moins gourmands en energie: refonte de la directive sur la performance energetique. Efficacite energetique dans les batiments: GDF Suez au rapport (volontaire)

    Energy Technology Data Exchange (ETDEWEB)

    Tourneur, J.C

    2009-10-15

    This dossier gathers a series of short articles about energy security and efficiency in a context of policy transition. The first paper deals with the use of international standards to promote energy efficiency thanks to efficient public policies and private sector actions. This was the main topic of the mixed workshop organized by the International electrotechnics Commission (IEC) in spring 2009. The second paper presents the new strategic analysis of the European commission in the domain of energy which stresses on the '20-20-20' climate change proposals approved in December 2008. A new European action plan for energy security and solidarity defines 5 domains requiring an extra action to warrant a sustainable energy supply. The commission is also examining the challenges that Europe will have to face between 2020 and 2050. The third article treats of the security of natural gas supplies which represents a quarter of the European Union (EU) energy mix. The supply crises susceptible to occur may have serious economic and social consequences. Therefore, the EU must be prepared to warrant its security of supplies. Cogeneration allows the EU to stay close to its energy goals. Buildings play a key role in the realisation of the EU's energy saving objectives and fight against climate change. The new directive on buildings energy efficiency (2002/91/CE) will allow to exploit this potential of saving and to stimulate sustainable investment and employment as well. Finally, the publication of the second WBCSD (World business council for sustainable development) international report on buildings energy efficiency has led GDF Suez utility to reaffirm its commitment in favour of energy saving and efficiency. (J.S.)

  6. Isolement des bactéries lactiques à partir des produits laitiers ...

    African Journals Online (AJOL)

    Isolement des bactéries lactiques à partir des produits laitiers traditionnels Marocains et formulation d'un lait fermenté proche du Kéfir. S Lairini, N Beqqali, R Bouslamti, R Belkhou, F Zerrouq ...

  7. Poser et reposer des choix.

    Directory of Open Access Journals (Sweden)

    Corinne Van Hauwermeiren- Echement

    2009-10-01

    Full Text Available IntroductionEn 1955, le legs de la collection Franckignoul – composée notamment d’un ensemble de quatre panneaux du XVIe siècle – vient enrichir les collections du Musée des Beaux-Arts de la Ville de Liège (Belgique. La fermeture de ce dernier en 1976 débouche sur  la scission des collections. Une partie est donnée au Musée de l’Art Wallon, l’autre partie allant au Musée d’Art Moderne et d’Art Contemporain (Mamac. Toutes les œuvres n’entrant pas dans ces deux collections sont reléguées en r...

  8. Signature spectrale des grains interstellaires.

    Science.gov (United States)

    Léger, A.

    Notre connaissance de la nature des grains interstellaires reposait sur un nombre très restreint de signatures spectrales dans la courbe d'extinction du milieu interstellaire. Une information considérable est contenue dans les 40 bandes interstellaires diffuses dans le visible, mais reste inexploitée. L'interprétation récente des cinq bandes IR en émission, en terme de molécules d'hydrocarbures aromatiques polycycliques, est développée. Elle permet l'utilisation d'une information spectroscopique comparable, à elle seule, à ce sur quoi était basée jusqu'alors notre connaissance de la matière interstellaire condensée. Différentes implications de cette mise en évidence sont proposées.

  9. Rapport officiel des Jeux COVAN

    OpenAIRE

    2011-01-01

    Le rapport officiel de Vancouver 2010 se présente sous une forme inédite : un livre commémoratif officiel publié par Wiley, “Des plus brillants exploits” et un coffret multimédia, “Guide du rapport après les Jeux: le rapport officiel des Jeux Olympiques et Paralympiques d'hiver de 2010 à Vancouver”. Ce dernier contient une brochure explicative, deux CD-ROM comprenant les textes et résultats officiels, ainsi que le DVD d’un film commémoratif, “Le Canada à l’échelle 2010”. Les deux volumes sont...

  10. Des maux pour le taire

    OpenAIRE

    Dussy, Dorothée; Caisne, Léonore Le

    2011-01-01

    Cette enquête ethnographique effectuée dans une association parisienne d’entraide aux victimes d’inceste montre que les enfants sexuellement abusés par un familier doivent se construire sur une double approche de la réalité sociale : d’un côté un discours dominant qui prône l’interdit de l’inceste et le respect des valeurs ordinaires, de l’autre l’expérience quotidienne des viols perpétrés par un de ceux qui transmettent ces valeurs. Grâce à un annonciateur, l’inceste perd son caractère anomi...

  11. Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, A

    2004-10-15

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  12. Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte-Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, A

    2004-10-01

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  13. La caravane des animaux. Circulation des « orangs-outans » et des savoirs, reconfigurations des frontières de l’humain

    OpenAIRE

    Sebastiani, Silvia

    2018-01-01

    L’article interroge la présence des animaux exotiques dans la Grande-Bretagne des Lumières, et en particulier des « orangs-outans ». Il retrace la mobilité de ces bêtes, met en lumière les réseaux au long cours de leur circulation, dessine les multiples espaces de sociabilité de leur mise en observation et le foisonnement des registres de discours dont ils font l’objet. Mis au cœur des travaux d’anatomie comparée dès la fin du xviie siècle, les orangs-outans deviennent l’une des grandes attra...

  14. Zukunft des IT-Sourcing

    OpenAIRE

    von Jouanne-Diedrich, Holger; Zarnekow, Rüdiger; Brenner, Walter

    2006-01-01

    Im Oktober 2005 wurden in Kooperation mit der Analystenfirma Gartner zwei Workshops in Frankfurt am Main und in München zum Thema Sourcing & Benchmarking durchgeführt. Diese wurde vom Autor H. v. Jouanne-Diedrich mit moderiert und wissenschaftlich begleitet. Thema war die Zukunft des IT-Sourcing, deren Management sich zunehmend den Herausforderungen einer Industrialisierung der IT stellen muss. Die 30 teilnehmenden Personen stammten dabei sowohl aus den Geschäftsbereichen als auch aus Bereich...

  15. Aspects echocardiographiques et etiologiques des ...

    African Journals Online (AJOL)

    Buts: Décrire les aspects échocardiographiques et étiologiques des cardiomyopathies chez le noir africain. Patients et méthodes: Il s'est agit d'une étude prospective réalisée à la clinique cardiologique du CHUCampus de Lomé du 1er janvier 2007 au 31 décembre 2009. Etaient inclus dans l'étude, les patients consultants ...

  16. Déplacements des gouverneurs

    International Development Research Centre (IDRC) Digital Library (Canada)

    André Lavoie

    Transit. Tout endroit qui n'est pas considéré comme la destination où l'on se rend par affaires. Voyageur. Désigne un gouverneur dans le contexte du présent règlement. 5. Rôles et responsabilités. 5.1. Personnes participant au processus lié aux déplacements des gouverneurs. Toutes les personnes, dont les gouverneurs, ...

  17. Biostratigraphie des foraminiferes et interpretation ...

    African Journals Online (AJOL)

    Les résultats montre que du bas vers le haut de l'intervalle, les sédiments sont des argiles noires qui passent progresssivement aux sables argileux et finallement au grés au sommet du puits. Les grès sont plus ou moins bien triés, anguleux à subanguleux, fins à grossiers. La présence de la pyrite diagénétique dans toute ...

  18. Renforcement des capacités d'adaptation des acteurs ruraux ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Renforcement des capacités d'adaptation des acteurs ruraux béninois face aux changements climatiques. Ce projet de recherche-action cherche à réduire la vulnérabilité des populations et les amener à mieux s'adapter aux changements climatiques. Le projet agit à trois niveaux hiérarchiques de décision, en facilitant des ...

  19. Perceptions locales des déterminants de la fragmentation des îlots ...

    African Journals Online (AJOL)

    SARAH

    30 juin 2013 ... Bariba estiment que l'érosion hydrique est le principal facteur de la fragmentation des forêts denses. Tandis que pour les Lokpa, et les Peulh, la fragmentation des forêts denses a pour cause la pauvreté des sols. De même, les groupes socioculturels estiment que la durée de la fragmentation des forêts ...

  20. Incidence des prix et des taxes sur la consommation de produits du ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Incidence des prix et des taxes sur la consommation de produits du tabac en Argentine, en Bolivie et au Chili. Partout en Amérique du Sud, les adultes et les enfants font une grande consommation de tabac. Un nouveau projet de recherche se penchera sur les avantages et les limites des stratégies de fixation des prix et de ...

  1. Renforcement de l'autonomie des collectivités au moyen des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cette subvention permettra au ministère des Communications et des Technologies de l'information de l'Égypte ainsi qu'au fonds spécial réservé aux TI de consolider le modèle actuel des clubs de TI en Égypte, par l'entremise de services d'assistance sur demande, d'activités de formation à l'intention du personnel des ...

  2. L'enrichissement des sols et des semences permet d'améliorer la ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    nutritifs des sols (par un engrais à base de zinc) et les méthodes de transformation des aliments utilisées par les ménages. Le bioenrichissement est un moyen .... rapport coût-efficacité d'ajouter des micronutriments à l'alimentation et d'améliorer l'état nutritionnel. L'accroissement de la fertilité des sols et du rendement.

  3. La participation des femmes à la vie politique se traduit par des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    La participation des femmes à la vie politique se traduit par des économies locales plus vigoureuses. 08 juin 2016. Image. Des femmes assistent à une réunion d'un groupe d'entraide près d'. Edgard Rodriguez - IDRC. Des femmes assistent à une réunion d'un groupe d'entraide près d'Hyderabad, en Inde. Keenara ...

  4. Gestion des côtes marocaines : renforcement des capacités d ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Gestion des côtes marocaines : renforcement des capacités d'adapter aux changements climatiques. Les répercussions de la hausse du niveau de la mer, de l'inondation des côtes et des ondes de tempête constituent un enjeu de plus en plus important en matière de politiques pour les planificateurs, les autorités locales ...

  5. Respect des normes de salubrité des aliments privées chez les ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Depuis quelques années, les petits exploitants agricoles des pays en développement se tournent vers l'étranger pour élargir leur marché. C'est pourquoi le respect des diverses normes de salubrité des aliments a gagné en importance. Le référentiel GLOBALGAP (anciennement EUREPGAP) est l'un des ensembles de ...

  6. OASIS : une architecture, des normes et des systèmes d'information ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    OASIS : une architecture, des normes et des systèmes d'information libres pour les services de santé en Afrique. Ce projet a pour but d'aider certains pays africains à concevoir puis à gérer des systèmes d'information sur la santé peu coûteux, viables et répondant aux besoins des établissements de santé et du secteur de ...

  7. Connaissances, attitudes et pratiques des prestataires de santé des ...

    African Journals Online (AJOL)

    ... des prestataires interrogés avaient respectivement une bonne connaissance des facteurs de risque et des moyens de dépistage. Les signes évocateurs et les examens complémentaires nécessaires au diagnostic du cancer du sein étaient connus par 15,3 % des prestataires. La définition du cancer du sein et les moyens ...

  8. Evaluation de l'abondance des kystes des protozoaires flagellés ...

    African Journals Online (AJOL)

    Les analyses statistiques montrent des corrélations significatives (P ≤ 0,05) entre la densité des kystes des protozoaires flagelles identifiées et les paramètres physico-chimiques tels que les MES, l'oxydabilité et la turbidité. Conclusions et application des resultsts: Les plantes doivent être bien lavées, désinfectées et bien ...

  9. Accès à l'eau : des solutions techniques et sociales aident des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Grâce à la modélisation par ordinateur faisant appel à des techniques de pointe et à la consultation des collectivités, l'organisme bolivien Agua Sustentable a trouvé des solutions politiques à des conflits qui auraient pu s'avérer désastreux au sujet de l'accès à l'eau. Cet organisme de recherche subventionné par le CRDI a ...

  10. Diagnostic des capteurs pour la commande des entrainements électriques

    OpenAIRE

    Diao , Sidath; DIALLO , Demba; MAKNI , Zaatar; Marchand , Claude

    2014-01-01

    Ce papier traite de la détection des défauts sur les capteurs pour un ensemble Machine Synchrone et Onduleur par des méthodes d'estimation d'état. Les capteurs à surveiller dans notre cas sont ceux de la position/vitesse et des courants de phase. Des résultats expérimentaux illustrent l'approche utilisée.

  11. Contribution des TICs à l'abandon des mutilations génitales ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le projet sera mené au Burkina Faso, au Mali et au Sénégal avec des collectifs de jeunes de communautés excisantes, disposant d'infrastructure de TIC et où sont menées des actions sur l'excision. Il permettra de sensibiliser des jeunes, des décideurs communautaires et le public à travers de rencontres réelles et ...

  12. Inventaire floristique et écologie des algues des rivières Kambo et ...

    African Journals Online (AJOL)

    L'objectif général de l'étude est de contribuer à la connaissance des algues des rivières Kambo et Longmayagui de Douala. Les objectifs spécifiques ont consisté à mesurer les paramètres physico-chimiques des rivières, de faire les inventaires des algues et d'en dégager les variations spatio-temporelles en relation avec ...

  13. Des collectivités forestières du Nigeria prennent des mesures pour ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Des collectivités forestières du Nigeria prennent des mesures pour réduire les émissions de carbone. 08 juin 2016. Image. Deforestation in Nigeria. Foreign and Commonwealth Office. En Afrique subsaharienne, il est crucial de conserver et de protéger les forêts pour assurer la durabilité des moyens de subsistance des ...

  14. Effets des changements socio-économiques sur les stratégies des ...

    African Journals Online (AJOL)

    Effets des changements socio-économiques sur les stratégies des agriculteurs des zones cotonnières d'Afrique Centrale. ... Cameroon Journal of Agricultural Science ... défensive de diversification des activités monétaires dès qu'un créneau économique peut être exploité, créant ainsi de nouvelles filières économiques.

  15. Sécurité des femmes et des personnes lesbiennes, gaies ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Sécurité des femmes et des personnes lesbiennes, gaies, bisexuelles, transgenres, intersexuées dans les régions touchées par les conflits en Colombie. La Colombie est en train de conclure les négociations de paix avec le groupe de rebelles des Forces armées révolutionnaires de Colombie (FARC). Une des attentes ...

  16. Évaluation des caractéristiques des stomates chez le palmier à huile ...

    African Journals Online (AJOL)

    SARAH

    31 août 2016 ... stomates chez le palmier à huile normal diploïde afin d'appliquer dans le futur les méthodes de la. Biotechnologie. Les objectifs spécifiques portent sur l'évaluation de la densité, de la longueur et de la largeur des stomates des feuilles de palmier à huile en fonction des variétés, de l'âge de la plante et des.

  17. Caractérisation des peuplements ligneux des parcs à Faidherbia ...

    African Journals Online (AJOL)

    SARAH

    31 oct. 2015 ... 1Département de Gestion des Ressources Naturelles (DGRN), Institut National de la Recherche Agronomique du. Niger (INRAN), BP 240 Maradi, Niger .... faciliter la gestion de ces ressources au profit des populations. Cette étude ...... très peu des rejets des souches relatifs à ces espèces ont été observés.

  18. Des pommes de terre plus saines et plus nutritives contribuent à la ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    De plus, les activités de recherche impliquant des femmes ont permis de redécouvrir des recettes ancestrales et des connaissances culinaires pour assaisonner des aliments avec des produits naturels plutôt qu'avec des condiments artificiels à haute teneur en sodium. Des institutions et des universités publiques ont.

  19. Modeling of the re-starting of waxy crude oil flows in pipelines; Modelisation du redemarrage des ecoulements de bruts paraffiniques dans les conduites petrolieres

    Energy Technology Data Exchange (ETDEWEB)

    Vinay, G.

    2005-11-15

    Pipelining crude oils that contain large proportions of paraffins can cause many specific difficulties. These oils, known as waxy crude oils, usually exhibit high 'pour point', where this temperature is higher than the external temperature conditions surrounding the pipeline. During the shutdown, since the temperature decreases in the pipeline, the gel-like structure builds up and the main difficulty concerns the issue of restarting. This PhD attempts to improve waxy crude oil behaviour understanding thanks to experiment, modelling and numerical simulation in order to predict more accurately time and pressure required to restart the flow. Using various contributions to the literature, waxy crude oils are described as viscoplastic, thixotropic and compressible fluid. Strong temperature history dependence plays a prevailing role in the whole shutdown and restart process. Thus, waxy crude oils under flowing conditions correspond to the non-isothermal flow of a viscoplastic material with temperature-dependent rheological properties. Besides, the restart of a waxy crude oil is simulated by the isothermal transient flow of a weakly compressible thixotropic fluid in axisymmetric pipe geometry. We retain the Houska model to describe the thixotropic/viscoplastic feature of the fluid and compressibility is introduced in the continuity equation. The viscoplastic constitutive equation is involved using an augmented Lagrangian method and the resulting equivalent saddle-point problem is solved thanks to an Uzawa-like algorithm. Governing equations are discretized using a Finite Volume method and the convection terms are treated thanks to a TVD (Total Variation Diminishing) scheme. The Lagrangian functional technique usually used for incompressible viscoplastic flows, is adapted to compressible situations. Several numerical results attest the good convergence properties of the proposed transient algorithm. The non-isothermal results highlight the strong sensitivity of

  20. ETUDE DE LA DISTRIBUTION DES CATIONS ECHANGEABLES

    African Journals Online (AJOL)

    SEI Joseph

    ces formations, la nature des phases minérales, les différentes phases de métamorphisme ayant affecté les corps minéralisés et les roches encaissantes, ainsi qu'une mise en évidence des différentes paragenèses entrant dans la composition des corps minéralisés [2,3]. Dans cette note, nous proposons la discussion de.

  1. Parasitisme des loranthaceae et association culturale en ...

    African Journals Online (AJOL)

    Cependant, quelques exceptions existent, liées notamment à la présence des arbres qui leur sont associés et qui sont densément parasités avec un degré moyen d'infestation de 32,65 p.c. et de 14,04 touffes/plante. Hevea brasiliensis, Mangifera indica et Myrianthus arboreus ont été épargnées des attaques des ...

  2. Developpement des systemes de production innovants d ...

    African Journals Online (AJOL)

    Pourtant, les associations maïs/légumineuses ont l'avantage d'améliorer la production et l'alimentation animale. Elles représentent une alternative dans la gestion des risques et des incertitudes pour les agro-éleveurs, confrontés aux changements globaux (climatiques, pression foncière, dégradation des ressources ...

  3. (TEC) et ciblage des pauvres au Mali

    International Development Research Centre (IDRC) Digital Library (Canada)

    Comment est-ce que c'est vrai. La preuve par … □ Différentiel de ciblage entre P et NP. □ Part normalisée de consommation/achat des Pauvres. □ Part normalisée de la pression fiscale. (totale et de porte) sur les achats des P. □ Part normalisée des "exonérations" revenant aux Pauvres ...

  4. La Gestion des Déchets Urbains

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le Service d'inspection des installations classées évolue actuellement en conformité avec les règlements français de 1926 régissant les établissements malsains, dérangeants ou dangereux. En effet, la loi ivoirienne, adoptée à la hâte en 1988 pendant la crise du transport des déchets radioactifs en provenance des pays ...

  5. Adaptation des organismes communautaires d'approvisionnement ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les villes connaissent également une croissance rapide, ce qui augmente la demande en eau. Ces changements réduisent la capacité des organismes communautaires à combler la demande en eau potable, la stabilité des sources d'eau étant menacée. Ce projet de recherche vise à étudier les effets des changements ...

  6. Hybrid meshes and domain decomposition for the modeling of oil reservoirs; Maillages hybrides et decomposition de domaine pour la modelisation des reservoirs petroliers

    Energy Technology Data Exchange (ETDEWEB)

    Gaiffe, St.

    2000-03-23

    In this thesis, we are interested in the modeling of fluid flow through porous media with 2-D and 3-D unstructured meshes, and in the use of domain decomposition methods. The behavior of flow through porous media is strongly influenced by heterogeneities: either large-scale lithological discontinuities or quite localized phenomena such as fluid flow in the neighbourhood of wells. In these two typical cases, an accurate consideration of the singularities requires the use of adapted meshes. After having shown the limits of classic meshes we present the future prospects offered by hybrid and flexible meshes. Next, we consider the generalization possibilities of the numerical schemes traditionally used in reservoir simulation and we draw two available approaches: mixed finite elements and U-finite volumes. The investigated phenomena being also characterized by different time-scales, special treatments in terms of time discretization on various parts of the domain are required. We think that the combination of domain decomposition methods with operator splitting techniques may provide a promising approach to obtain high flexibility for a local tune-steps management. Consequently, we develop a new numerical scheme for linear parabolic equations which allows to get a higher flexibility in the local space and time steps management. To conclude, a priori estimates and error estimates on the two variables of interest, namely the pressure and the velocity are proposed. (author)

  7. Interdiffusion of the aluminum magnesium system. Quantitative analysis and numerical model; Interdiffusion des Aluminium-Magnesium-Systems. Quantitative Analyse und numerische Modellierung

    Energy Technology Data Exchange (ETDEWEB)

    Seperant, Florian

    2012-03-21

    Aluminum coatings are a promising approach to protect magnesium alloys against corrosion and thereby making them accessible to a variety of technical applications. Thermal treatment enhances the adhesion of the aluminium coating on magnesium by interdiffusion. For a deeper understanding of the diffusion process at the interface, a quantitative description of the Al-Mg system is necessary. On the basis of diffusion experiments with infinite reservoirs of aluminum and magnesium, the interdiffusion coefficients of the intermetallic phases of the Al-Mg-system are calculated with the Sauer-Freise method for the first time. To solve contradictions in the literature concerning the intrinsic diffusion coefficients, the possibility of a bifurcation of the Kirkendall plane is considered. Furthermore, a physico-chemical description of interdiffusion is provided to interpret the observed phase transitions. The developed numerical model is based on a temporally varied discretization of the space coordinate. It exhibits excellent quantitative agreement with the experimentally measured concentration profile. This confirms the validity of the obtained diffusion coefficients. Moreover, the Kirkendall shift in the Al-Mg system is simulated for the first time. Systems with thin aluminum coatings on magnesium also exhibit a good correlation between simulated and experimental concentration profiles. Thus, the diffusion coefficients are also valid for Al-coated systems. Hence, it is possible to derive parameters for a thermal treatment by simulation, resulting in an optimized modification of the magnesium surface for technical applications.

  8. A New Model to Calculate Three-Phase Relative Permeabilities: Application and Validation for a Sandstone Un nouveau modèle pour le calcul des perméabilités relatives en écoulement triphasique : application et validation dans le cas d'un grès

    Directory of Open Access Journals (Sweden)

    Moulu J. C.

    2006-12-01

    Full Text Available Three-phase flow in a porous medium is usually described by the Stone model (1970. This model is based on two-phase data and relies on empirical correlations. It is valid only under strong water wettability and recognized as being a poor predictor. The goal of the present study is to develop a mathematical model for three-phase flow avoiding any empirical correlations. In this paper, only strong water-wet and spreading conditions are considered. However the model could be relatively easily extended to oil-wet or even mixed-wet conditions. The model is based on a physically relevant description of phase distribution and flow mechanisms at the pore scale. The porous medium is described as a set of fractal pores, whose linear fractal dimension and size distributions are derived from a mercury intrusion capillary pressure curve. The fluids are allowed to flow together in the same fractal pore, gas in the center, water near the walls and oil in an intermediate phase. The relative permeabilities are evaluated by calculating the flow of each fluid applying Poiseuille's law. The model results are compared to relative permeabilities obtained by history matching of gas injection experiments. The same experiments are also simulated using Stone's model and laboratory measured two-phase data. Les écoulements triphasiques en milieu poreux sont généralement décrits par le modèle de Stone (1970. Ce modèle est basé sur des corrélations empiriques appliquées à des résultats d'écoulements diphasiques. Il n'est valable que dans le cas de mouillabilité franche à l'eau et ne peut pas être utilisé comme outil de prédiction. L'objectif de la présente étude est de développer un modèle mathématique d'écoulement triphasique en évitant toute corrélation empirique. Dans cet article, les conditions de mouillabilité franche à l'eau et d'étalement sont seules étudiées, mais le modèle pourrait être aisément étendu aux cas de mouillabilité à l

  9. Contribution des TICs à l'abandon des mutilations génitales ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Contribution des TIC à l'abandon des MGF en Afrique de l'Ouest francophone : rôle des jeunes citoyennes; rapport technique no. 5 (rapport technique final), 18 octobre 2008 - 31 mars 2009. Download PDF. Related content. New website will help record vital life events to improve access to services for all. A new website ...

  10. Etat des lieux de la gestion des insecticides au Togo, Afrique de l ...

    African Journals Online (AJOL)

    Pour parvenir à une gestion optimale des maladies à transmission vectorielle ou tout au moins la nuisance culicidienne, une surveillance permanente des facteurs de risque devient nécessaire. Le principal facteur de risque est le vecteur qui transmet la maladie, et le contrôle du vecteur passe par des stratégies de lutte qui ...

  11. Qualité microbiologique des eaux des fleuves Nyong et Wouri ...

    African Journals Online (AJOL)

    Qualité microbiologique des eaux des fleuves Nyong et Wouri (Cameroun) et impact potentiel sur la santé des populations riveraines. Larissa Abologo Azeme, Claudine Mireille Ntsama Essomba, Lucie Leme Banock, Charles Félix Bilong Bilong ...

  12. Evaluation de l\\'activité hémagglutinante des lectines des graines de ...

    African Journals Online (AJOL)

    % de saturation, de l\\'extrait brut de Csp présente l\\'activité hémagglutinante la plus élevée (512). Le traitement thermique à 100°C pendant 15 minutes réduit significativement l\\'activité hémagglutinante des lectines des extraits bruts des graines ...

  13. Association des universités africaines - section des TIC pour les ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Association des universités africaines - section des TIC pour les réseaux nationaux de recherche et d'éducation. L'Association ... Africa's New Frontier : Innovation. Technology. ... L'Initiative des conseils subventionnaires de la recherche scientifique en Afrique subsaharienne remporte le prix de la diplomatie scientifique.

  14. Emploi des jeunes et autonomisation économique des femmes en ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Emploi des jeunes et autonomisation économique des femmes en Afrique : le rôle des petites et moyennes entreprises dans le secteur du tourisme ... le secteur du tourisme menées par les gouvernements et leurs partenaires, participera à la formulation de recommandations stratégiques fiables, et renforcera les capacités ...

  15. Vivre et survivre au bord des villes

    Directory of Open Access Journals (Sweden)

    Michel Péraldi

    1996-04-01

    Full Text Available De quels revenus vivent, ou plutôt survivent, les populations des quartiers dits défavorisés ? Telle est, malgré son apparente banalité, la question qui initie aujourd'hui une partie de nos recherches. Question banale en effet puisque les médias et le débat politique nous donnent une réponse sans appel, statistiquement fiable : dans ces univers sociaux où se croisent des communautés issues des plus récentes migrations et les fractions les plus fragiles économiquement des classes populaires fr...

  16. Modalites de consommation et valeur nutritionnelle des ...

    African Journals Online (AJOL)

    Les légumineuses niébé, voandzou et zamnè sont consommées sous forme de ragout et de plats associés à des céréales respectivement par 99%, 93% et 76%. L'arachide et le soja sont utilisés comme des ingrédients ou comme des collations. Les légumineuses ont des teneurs importantes en protéines, 35,76%, 31,04%, ...

  17. Fusion des bourses : analyse de cas

    OpenAIRE

    Frunz, Dylan; Tuchschmid, Nils

    2013-01-01

    Dans le cadre de mon travail de Bachelor, je vais tenter de déterminer les raisons et conséquences des importantes fusions actuelles entre bourses historiques mondiales. Les bourses, représentées par leurs différents indices, représentent le niveau actuel de l’économie des pays par le biais des nombreuses sociétés y étant cotées. Le regroupement des activités entre bourses traditionnelles s’est dessiné avec pour objectif de contrer la nouvelle concurrence, apparue suite à la nouvelle directiv...

  18. Liste des abréviations

    OpenAIRE

    2014-01-01

    AI : Amnesty International CADH : Convention américaine des droits de l'homme CEDH : Commission européenne des droits de l'homme CIDH : Commission interaméricaine des droits de l'homme CIJ : Cour internationale de Justice ECOSOC : Economic and Social Council (UN) IACHR : Inter-American Commission on Human Rights IIJ :Instituto de Investigaciones Jurídicas (UNAM) IIDH : Instituto Interamericano de Derechos Humanos LGDJ : Librairie générale de droit et de jurisprudence OEA : Organisation des Ét...

  19. Évaluation de la valeur nutritive et recherche des substances ...

    African Journals Online (AJOL)

    Puis, l'évaluation a été effectuée sur ces échantillons pour rechercher la présence des alcaloïdes, des saponines, des quinones, des stéroïdes, des terpenoïdes, des flavonoïdes, des leucoanthocyanes, des tannoïdes et des hétérosides cyanogénétiques. Les teneurs moyennes en humidité, en cendres, en protéines, en ...

  20. Modeling of engine hydrodynamics equations on hybrid unstructured meshes; Modelisation des equations de l`hydrodynamique moteur sur maillage non structure hybride

    Energy Technology Data Exchange (ETDEWEB)

    Durand, A.

    1996-10-10

    In this thesis, we are interested in the modeling of the compressible Navier-Stokes equations in 2-D moving domains with hybrid meshes. This work, far from being restricted to these equations, could be generalized to any other convection-diffusion system written in conservative vector form. After having described the mathematical equations and elaborated on finite volume (FV) methods, numerical schemes and various meshes, we have selected the Galerkin FV method. This method consists in locating the unknowns at the mesh nodes, then in solving the convective terms by means of VF method - quasi 1-D by edge approximation - and the diffusive terms by means of the finite element (FE) method - P{sub 1} for the triangular and Q{sub 1} for the quadrilateral. The equivalence between the Galerkin FV method and a mass-lumped FE method for temporal terms allows the construction of a new control volume constructed by means of medians. Then, show its interest in comparison to the classical control volume constructed by means of medians. Then first-order in comparison to the classical control volume constructed bu means of medians. Then, the first-order Roe scheme and its extension to second-order by the MUSCL method are detailed Emphasis is laid on two calculations oF the Gradient integral. Numerous numerical tests as well as the comparison with another code validate the approach. In particular, we show that triangular meshes lead to less precise results compared to quadrilateral meshes in certain cases. Afterward, we switch to the dimensionless Navier-Stokes equations and we describe a simplified (Bubnov)-Galerkin FE method in the case of the quadrilaterals. The newly deduced computer code is validated bu the means of a vortex convection-diffusion for different Reynolds numbers. This test shows that only highly viscous flows give rise to equivalent solutions for both meshes. (author)