Suchergebnisse

In the daily life, we are exposed to electromagnetic fields. One of the sources of these fields is the natural environment, but they are also dues to the increasing number of electrical appliances. Thus one is more and more concerned with the issue of the effects of this exposure on human health. The low frequency magnetic fields generate induced currents into the human body. These currents may produce some minor, reversible effects (phosphenes) for J=100mA/m2. On the other hand, the long-term effects of this exposure remain not well known. Basing upon the Principle of Precautions, the governments are upgrading the industrial standards concerning non-ionizing radiations. For low frequency (magnetic) fields, some maximum admissible values are defined for the induced current density into the human body J, and for the flux density B. These limits have been defined on the basis of biological thresholds and simple analytical computations, with some security factors. The knowledge of the sole flux density B is not enough to quantify the induced currents into the human body J, because the magnetic field decreases quickly in proximity of the radiating source (where high exposure is likely to occur), but also owing to the heterogeneity of the human body. Besides, these induced currents J are not measurable in vivo. This Ph.D. thesis is devoted to the development of models and numerical tools to simulate the induced phenomena in the human body, in the frequency range of 50 Hz – 100 kHz. Two main problems are studied: - how to determine the spatial distribution of the magnetic field radiated by an electrical appliance (stray field) - how to compute the induced currents into the human body. To this aim, the influence of several parameters on the distribution of the stray field is first studied, and the different numerical techniques to predict the field radiated by a known source are reviewed. This preliminary study shows that conventional methods are not well adapted to compute the radiated field in the air. Hence, a new 3D model is proposed. This model takes into account only the essential features of the radiating source, and thus it is faster and cheaper than ordinary methods, but still accurate enough. In the proposed model, a system of fictive charges is used to compute the stray field. This model has been validated using some simple geometrical structures (coil + magnetic core + air-gap). The exposure to the field can be also originated by sources, whose inner structure is unknown. Thus, an experimental system has been developed, with the purpose to characterize the stray field with a few measurements. To this aim, several models based on the concept of dipole and multipole have been developed. The problem of estimating the parameters of these models is found to be very ill posed: thus some regularization techniques have been implemented. The feasibility has been shown using simple electrical structures. Finally, a special 3D electromagnetic formulation is presented. This formulation is well adapted to the computation of induced currents into the human body, and has been implemented by the finite elements techniques. The computational domain is bounded to the sole human body: thus, some simple geometrical structures, but also a fine anatomical structure composed of several "materials" (= organs), can be used to describe the human body. Using these tools, several exposure situations have been simulated. Some wire systems, but also more realistic structures, have been chosen as radiating sources. The applications in the normative and industrial context may be very important. ; Ce travail de thèse est consacré au développement de modèles et outils numériques permettant la simulation dans la gamme des fréquences 50 Hz¡100 kHz des phénomènes induits par des champs magnétiques dans le corps humain. Pour cela, il existe deux problématiques principales : - Déterminer la répartition du champ rayonné (ou champ de fuite) par un appareil électrique . - Calculer les courants induits qui en résultent dans le corps humain. Après avoir étudié l'influence de divers paramètres sur la répartition des champs de fuite générés par les systèmes électrotechniques, nous avons recensé les méthodes numériques aptes à calculer ce champ pour des systèmes connus. Cette étude montre que ces méthodes en l'état ne sont pas adaptées au calcul des champs dans l'air, car trop coûteuses. Nous présentons donc un modèle 3D ne prenant en compte que les aspects essentiels de la géométrie du système, beaucoup moins coûteux et suffisamment précis. Dans ce modèle, le champ de fuites est calculé à partir d'une représentation en termes de charges magnétiques fictives. Ce modèle a été validé sur des structures géométriques simples, de type bobine + circuit magnétique + entrefer. L'exposition aux champs en milieu industriel ou domestique est également due à des sources dont la structure est inconnue. Nous avons donc développé un système expérimental, permettant de caractériser le champ de fuites à partir d'un nombre minimum de mesures localisées. Pour cela, nous avons développé divers modèles de la source rayonnante s'appuyant sur les notions de dipôle et multipôles. Nous nous sommes consacrés au divers problèmes d'estimation (influence du choix des mesures, prise en compte du bruit). Le problème étant mal conditionné, des techniques de régularisation ont été mises en oeuvre. La faisabilité a été démontrée sur des structures rayonnantes simples. Enfin, nous présentons une formulation 3D adaptée pour calculer les courants induits dans le corps humain, à partir de la connaissance des champs de fuites. Cette formulation a été implémentée dans un code aux éléments finis, dans lequel le domaine de résolution est limité au seul corps humain : ce code permet de modéliser des structures anatomiques réalistes où les valeurs des conductivités des divers organes sont prises en compte. Différentes situations d'exposition du corps aux rayonnements issus de sources simples filaires, et à des sources réelles ont pu être ainsi simulées, et les applications notamment dans des contextes normatif et industriel sont particulièrement importantes.

In the daily life, we are exposed to electromagnetic fields. One of the sources of these fields is the natural environment, but they are also dues to the increasing number of electrical appliances. Thus one is more and more concerned with the issue of the effects of this exposure on human health. The low frequency magnetic fields generate induced currents into the human body. These currents may produce some minor, reversible effects (phosphenes) for J=100mA/m2. On the other hand, the long-term effects of this exposure remain not well known. Basing upon the Principle of Precautions, the governments are upgrading the industrial standards concerning non-ionizing radiations. For low frequency (magnetic) fields, some maximum admissible values are defined for the induced current density into the human body J, and for the flux density B. These limits have been defined on the basis of biological thresholds and simple analytical computations, with some security factors. The knowledge of the sole flux density B is not enough to quantify the induced currents into the human body J, because the magnetic field decreases quickly in proximity of the radiating source (where high exposure is likely to occur), but also owing to the heterogeneity of the human body. Besides, these induced currents J are not measurable in vivo. This Ph.D. thesis is devoted to the development of models and numerical tools to simulate the induced phenomena in the human body, in the frequency range of 50 Hz – 100 kHz. Two main problems are studied: - how to determine the spatial distribution of the magnetic field radiated by an electrical appliance (stray field) - how to compute the induced currents into the human body. To this aim, the influence of several parameters on the distribution of the stray field is first studied, and the different numerical techniques to predict the field radiated by a known source are reviewed. This preliminary study shows that conventional methods are not well adapted to compute the radiated field in the air. Hence, a new 3D model is proposed. This model takes into account only the essential features of the radiating source, and thus it is faster and cheaper than ordinary methods, but still accurate enough. In the proposed model, a system of fictive charges is used to compute the stray field. This model has been validated using some simple geometrical structures (coil + magnetic core + air-gap). The exposure to the field can be also originated by sources, whose inner structure is unknown. Thus, an experimental system has been developed, with the purpose to characterize the stray field with a few measurements. To this aim, several models based on the concept of dipole and multipole have been developed. The problem of estimating the parameters of these models is found to be very ill posed: thus some regularization techniques have been implemented. The feasibility has been shown using simple electrical structures. Finally, a special 3D electromagnetic formulation is presented. This formulation is well adapted to the computation of induced currents into the human body, and has been implemented by the finite elements techniques. The computational domain is bounded to the sole human body: thus, some simple geometrical structures, but also a fine anatomical structure composed of several "materials" (= organs), can be used to describe the human body. Using these tools, several exposure situations have been simulated. Some wire systems, but also more realistic structures, have been chosen as radiating sources. The applications in the normative and industrial context may be very important. ; Ce travail de thèse est consacré au développement de modèles et outils numériques permettant la simulation dans la gamme des fréquences 50 Hz¡100 kHz des phénomènes induits par des champs magnétiques dans le corps humain. Pour cela, il existe deux problématiques principales : - Déterminer la répartition du champ rayonné (ou champ de fuite) par un appareil électrique . - Calculer les courants induits qui en résultent dans le corps humain. Après avoir étudié l'influence de divers paramètres sur la répartition des champs de fuite générés par les systèmes électrotechniques, nous avons recensé les méthodes numériques aptes à calculer ce champ pour des systèmes connus. Cette étude montre que ces méthodes en l'état ne sont pas adaptées au calcul des champs dans l'air, car trop coûteuses. Nous présentons donc un modèle 3D ne prenant en compte que les aspects essentiels de la géométrie du système, beaucoup moins coûteux et suffisamment précis. Dans ce modèle, le champ de fuites est calculé à partir d'une représentation en termes de charges magnétiques fictives. Ce modèle a été validé sur des structures géométriques simples, de type bobine + circuit magnétique + entrefer. L'exposition aux champs en milieu industriel ou domestique est également due à des sources dont la structure est inconnue. Nous avons donc développé un système expérimental, permettant de caractériser le champ de fuites à partir d'un nombre minimum de mesures localisées. Pour cela, nous avons développé divers modèles de la source rayonnante s'appuyant sur les notions de dipôle et multipôles. Nous nous sommes consacrés au divers problèmes d'estimation (influence du choix des mesures, prise en compte du bruit). Le problème étant mal conditionné, des techniques de régularisation ont été mises en oeuvre. La faisabilité a été démontrée sur des structures rayonnantes simples. Enfin, nous présentons une formulation 3D adaptée pour calculer les courants induits dans le corps humain, à partir de la connaissance des champs de fuites. Cette formulation a été implémentée dans un code aux éléments finis, dans lequel le domaine de résolution est limité au seul corps humain : ce code permet de modéliser des structures anatomiques réalistes où les valeurs des conductivités des divers organes sont prises en compte. Différentes situations d'exposition du corps aux rayonnements issus de sources simples filaires, et à des sources réelles ont pu être ainsi simulées, et les applications notamment dans des contextes normatif et industriel sont particulièrement importantes.

17 pages Texte de la présentation effectuée lors du Colloque de l'A.R.F. (Association des Ruralistes Français), Toulouse, octobre 2000 ; The permanent rebuilding of the village through its festivals. The study of the popular rural joyrides (balls and lottos) emphasizes permanence of two territorial structures instances anchored in mentalities In France, the traditionally strong political dimension of the administrative and local authority framework (the "commune", 36 678 on the whole country) has induced an old confusion with lived space (the "village"). This un-determination between both instances of places design remains one of major structuringX of spatiality, particularly in rural places. This confusion is likely to generate divergences whereas have been developed for a few years a dynamic movement of inter-communality (at least, 5 to 7000 on the whole France) to produce a new rational territories management and adapt them to the European context (from the LAU 2, local, to LAU 1, sub-local, but with powers, areas and population of the LAU 2 in most European countries: Spain, Germany, Belgium, Portugal or Italy). This paper reports some studies about these structures and their move induced by the mean of the fetes (balls) like other major ludic activities ("lotos" or public associative bingos). It brings to doubtX the speed of this new frameworks rooting. Indeed, on the contrary, at the same time the considerable widening of life spaces caused by an increasing mobility of rural people causes over-estimation and a complete rebuilding of the representations of the commune/village framework known as "traditional" by adopting behaviours and the models issued from the periurban spaces. Dominique Crozat Lecturer Mutations des Territoires en Europe UMR 5045, CNRS-Universities of Montpellier 3 and Perpignan Department of geography University Paul Valéry Montpellier 3 F-34199 Montpellier Tel . 33- (0)4 67 14 22 49 Mobile 06 32 51 86 42 d.crozat@ades.cnrs.fr dominique.crozat@univ-montp3.fr ...

La crise liée au Covid-19 touche toutes les sphères sociétales et toutes les professions. Dans le domaine de l'éducation, le gouvernement invite les différentes structures éducatives à assurer une forme de continuité pédagogique en lien avec la culture du numérique (Licoppe, 2009). Pour guider ces transformations pédagogiques, l'école, le collège, le lycée, ou encore l'université demandent à leurs équipes pédagogiques de proposer au plus vite des dispositifs d'apprentissage innovants (Caron-Fasan et Parmentier, 2019). La présente recherche étudie la « coprésence à distance » (Relieu et Morel, 2011) induite par une classe virtuelle telle que construite au sein d'un collège du sud de la France. Les représentations du sens, du temps et de l'espace sont questionnées. ; The Covid-19 crisis affects all societal spheres and all professions. In the realm of education, the government invites the different educational structures to ensure a form of educational continuity in connection with digital culture (Licoppe, 2009). In order to guide these educational transformations, the primary school, secondary school, high school, or even university ask their teaching teams to offer innovative learning devices as quickly as possible (Caron-Fasan, Parmentier, 2019). This research studies the "remote co-presence" (Relieu, Morel, 2011) induced by a virtual classroom as constructed within a secondary school in the south of France. The representations of meaning, time and space are being questioned.

The Dassault Aviation Group designs and builds a wide range of aircraft models each year, for both private and military use. Some structural parts of the aircraft, in the form of reinforced stiffener panels machined directly into the bulk of Al2024T351 thick plates are studied. As part of the shaping process, these elements must be cold formed to give their final curvature. This process severely plastified some regions of the structure. In addition, these zones are likely to constitute sites of initiation and propagation of fatigue cracks.This study aims to analyze the interactions between the plastic phenomena induced by cold forming and the propagation of a fatigue crack during fatigue service loading. This thesis is conducted according to the following approach:An instrumented cold forming test has been performed on two self-stiffening technological specimens. From an experimental base of tensile tests, a model of anisotropic plastic behavior of the plate was proposed allowing the development of a cold forming structure simulation and an analysis of the residual state of the material following the process. Using all the results about residual plastic state, a compression and traction test on large test pieces has been performed (54 mm diameter slugs and flat tensile test pieces of 75x55 mm section) whose purpose is to produce a homogeneous volume of pre-deformed material in compression and traction (+/-10 % of plasticity) .A large campaign of fatigue tests has been realized on oligocyclic specimens and specimens of propagation (Compact Tension) extracted from the volumes of original and pre-deformed material allowing the characterization of the effects of the pre-deformation on the fatigue properties. A modified Forman propagation model has been identified from the velocity curves.Finally, self-stiffened structures formed have been subjected to a cyclic loading and the fatigue initiation and propagation behavior has been observed experimentally. A simulation of the fatigue loading of the structure after ...

Document 1: Presentation of the doctoral research dossierThis document presents the general framework of the doctoral research dossier. It intends to briefly explain the research methodology, in order to better understand the dual approach adopted and the structure of this doctoral research. On the one hand, the dossier is based on several articles published on the issue of forest certification schemes political transformations. On the other hand, the dossier includes a research on the issue of environmental effectiveness of rainforest management devices. This first document introduces the critical stand, the issues addressed and the disciplines involved in these two approaches. Finally, the prospects offered by this research are mentioned.Document 2: Political transformations induced by the development of forest management certification: the case of FSC.This document analyses the political impact of a forest management certification device: the Forest Steward Council (FSC). It integrates five articles published in academic/scientific books and journals between 2007 and 2011, which were published in the framework of the NORMES research project "Regulation by standards : the instruments of regulations in the governance of sustainable development", financed by the French National Agency of Research (ANR). The publications are preceded by a framing text which presents the background and the working of the FSC-instrument, and then introduces the texts succinctly.The research activities permit to enhance the understanding of political transformations, induced by the FSC. The institutional innovations which were produced by the FSC will be emphasized, as well as the reach and the limits of this voluntary instrument, the behavorial changes it brings about, and the side-effects it generates, in particular in terms of equity between the concerned players in this field.Finally, the analysis of the public-private relations shows that, far from being a private and isolated instrument, the FSC exerts a certain influence on ...

Document 1: Presentation of the doctoral research dossierThis document presents the general framework of the doctoral research dossier. It intends to briefly explain the research methodology, in order to better understand the dual approach adopted and the structure of this doctoral research. On the one hand, the dossier is based on several articles published on the issue of forest certification schemes political transformations. On the other hand, the dossier includes a research on the issue of environmental effectiveness of rainforest management devices. This first document introduces the critical stand, the issues addressed and the disciplines involved in these two approaches. Finally, the prospects offered by this research are mentioned.Document 2: Political transformations induced by the development of forest management certification: the case of FSC.This document analyses the political impact of a forest management certification device: the Forest Steward Council (FSC). It integrates five articles published in academic/scientific books and journals between 2007 and 2011, which were published in the framework of the NORMES research project "Regulation by standards : the instruments of regulations in the governance of sustainable development", financed by the French National Agency of Research (ANR). The publications are preceded by a framing text which presents the background and the working of the FSC-instrument, and then introduces the texts succinctly.The research activities permit to enhance the understanding of political transformations, induced by the FSC. The institutional innovations which were produced by the FSC will be emphasized, as well as the reach and the limits of this voluntary instrument, the behavorial changes it brings about, and the side-effects it generates, in particular in terms of equity between the concerned players in this field.Finally, the analysis of the public-private relations shows that, far from being a private and isolated instrument, the FSC exerts a certain influence on ...

Document 1: Presentation of the doctoral research dossierThis document presents the general framework of the doctoral research dossier. It intends to briefly explain the research methodology, in order to better understand the dual approach adopted and the structure of this doctoral research. On the one hand, the dossier is based on several articles published on the issue of forest certification schemes political transformations. On the other hand, the dossier includes a research on the issue of environmental effectiveness of rainforest management devices. This first document introduces the critical stand, the issues addressed and the disciplines involved in these two approaches. Finally, the prospects offered by this research are mentioned.Document 2: Political transformations induced by the development of forest management certification: the case of FSC.This document analyses the political impact of a forest management certification device: the Forest Steward Council (FSC). It integrates five articles published in academic/scientific books and journals between 2007 and 2011, which were published in the framework of the NORMES research project "Regulation by standards : the instruments of regulations in the governance of sustainable development", financed by the French National Agency of Research (ANR). The publications are preceded by a framing text which presents the background and the working of the FSC-instrument, and then introduces the texts succinctly.The research activities permit to enhance the understanding of political transformations, induced by the FSC. The institutional innovations which were produced by the FSC will be emphasized, as well as the reach and the limits of this voluntary instrument, the behavorial changes it brings about, and the side-effects it generates, in particular in terms of equity between the concerned players in this field.Finally, the analysis of the public-private relations shows that, far from being a private and isolated instrument, the FSC exerts a certain influence on ...

Document 1: Presentation of the doctoral research dossierThis document presents the general framework of the doctoral research dossier. It intends to briefly explain the research methodology, in order to better understand the dual approach adopted and the structure of this doctoral research. On the one hand, the dossier is based on several articles published on the issue of forest certification schemes political transformations. On the other hand, the dossier includes a research on the issue of environmental effectiveness of rainforest management devices. This first document introduces the critical stand, the issues addressed and the disciplines involved in these two approaches. Finally, the prospects offered by this research are mentioned.Document 2: Political transformations induced by the development of forest management certification: the case of FSC.This document analyses the political impact of a forest management certification device: the Forest Steward Council (FSC). It integrates five articles published in academic/scientific books and journals between 2007 and 2011, which were published in the framework of the NORMES research project "Regulation by standards : the instruments of regulations in the governance of sustainable development", financed by the French National Agency of Research (ANR). The publications are preceded by a framing text which presents the background and the working of the FSC-instrument, and then introduces the texts succinctly.The research activities permit to enhance the understanding of political transformations, induced by the FSC. The institutional innovations which were produced by the FSC will be emphasized, as well as the reach and the limits of this voluntary instrument, the behavorial changes it brings about, and the side-effects it generates, in particular in terms of equity between the concerned players in this field.Finally, the analysis of the public-private relations shows that, far from being a private and isolated instrument, the FSC exerts a certain influence on ...

Document 1: Presentation of the doctoral research dossierThis document presents the general framework of the doctoral research dossier. It intends to briefly explain the research methodology, in order to better understand the dual approach adopted and the structure of this doctoral research. On the one hand, the dossier is based on several articles published on the issue of forest certification schemes political transformations. On the other hand, the dossier includes a research on the issue of environmental effectiveness of rainforest management devices. This first document introduces the critical stand, the issues addressed and the disciplines involved in these two approaches. Finally, the prospects offered by this research are mentioned.Document 2: Political transformations induced by the development of forest management certification: the case of FSC.This document analyses the political impact of a forest management certification device: the Forest Steward Council (FSC). It integrates five articles published in academic/scientific books and journals between 2007 and 2011, which were published in the framework of the NORMES research project "Regulation by standards : the instruments of regulations in the governance of sustainable development", financed by the French National Agency of Research (ANR). The publications are preceded by a framing text which presents the background and the working of the FSC-instrument, and then introduces the texts succinctly.The research activities permit to enhance the understanding of political transformations, induced by the FSC. The institutional innovations which were produced by the FSC will be emphasized, as well as the reach and the limits of this voluntary instrument, the behavorial changes it brings about, and the side-effects it generates, in particular in terms of equity between the concerned players in this field.Finally, the analysis of the public-private relations shows that, far from being a private and isolated instrument, the FSC exerts a certain influence on ...

As policies to fight greenhouse gas emissions are more and more demanding and as the global energy demand is constantly increasing, renewable energies are currently seen as an important contribution to the global energy mix. Among them, tidal energy has the advantage of a perfectly known and highly predictable intermittency. The present work is part of the PoHyCA (Hydrodynamic Pump for Air Compression) project led by Segula Technologies, consisting in the realization of an innovative hydrodynamic pump for air compression and storage. The final objective is the production of electrical energy. PoHyCA technology captures the energy of sea currents using an oscillating hydrofoil that moves under the effect of hydrodynamic forces from the surrounding flow. This work focus on the evaluation of the dynamics of the deformable hydrofoil. A fluid-structure interaction (FSI) approach, using an implicit coupling scheme, is implemented to account for the deformations of the structure, induced by hydrodynamic forces. The numerical model also takes into account the large pitching and heaving displacements of the structure. It is first applied to a rigid oscillating plate experimentally documented in the literature, and similar results are obtained. We show that the flexibility of the profile leads in particular to a reduction in propulsion capability. The model is then applied to a hydrofoil subjected to an oscillating heaving and pitching motion. We show that in certain configurations, blade deformations can improve energy efficiency. ; Les politiques de lutte contre les émissions de CO2 étant de plus en plus exigeantes et la demande énergétique étant en constante augmentation, les énergies renouvelables sont perçues actuellement comme devant être un apport important dans le mix énergétique mondial. Parmi elles, l'énergie hydrolienne présente l'avantage d'une intermittence parfaitement connue et très prédictible. La recherche de cette thèse s'inscrit dans le cadre du projet PoHyCA (Pompe Hydrodynamique pour la Compression ...

As policies to fight greenhouse gas emissions are more and more demanding and as the global energy demand is constantly increasing, renewable energies are currently seen as an important contribution to the global energy mix. Among them, tidal energy has the advantage of a perfectly known and highly predictable intermittency. The present work is part of the PoHyCA (Hydrodynamic Pump for Air Compression) project led by Segula Technologies, consisting in the realization of an innovative hydrodynamic pump for air compression and storage. The final objective is the production of electrical energy. PoHyCA technology captures the energy of sea currents using an oscillating hydrofoil that moves under the effect of hydrodynamic forces from the surrounding flow. This work focus on the evaluation of the dynamics of the deformable hydrofoil. A fluid-structure interaction (FSI) approach, using an implicit coupling scheme, is implemented to account for the deformations of the structure, induced by hydrodynamic forces. The numerical model also takes into account the large pitching and heaving displacements of the structure. It is first applied to a rigid oscillating plate experimentally documented in the literature, and similar results are obtained. We show that the flexibility of the profile leads in particular to a reduction in propulsion capability. The model is then applied to a hydrofoil subjected to an oscillating heaving and pitching motion. We show that in certain configurations, blade deformations can improve energy efficiency. ; Les politiques de lutte contre les émissions de CO2 étant de plus en plus exigeantes et la demande énergétique étant en constante augmentation, les énergies renouvelables sont perçues actuellement comme devant être un apport important dans le mix énergétique mondial. Parmi elles, l'énergie hydrolienne présente l'avantage d'une intermittence parfaitement connue et très prédictible. La recherche de cette thèse s'inscrit dans le cadre du projet PoHyCA (Pompe Hydrodynamique pour la Compression ...

As part of the energy transition, the French government is planning the construction of eight Offshore Wind Farms (OWF) along the English Channel and Atlantic coasts including the Courseulles-sur-mer OWF. Until now, there is no holistic study on the OWF construction and operation effects on an ecosystem taken as a whole. This thesis is the first study to lay the foundations for an ecosystem approach of Marine Renewable Energy (MRE) through the Courseulles-sur-mer OWF example. For that a combination of innovative modelling tools was applied to 1) characterise the ecosystem structure and functioning before the OWF construction; 2) simulate the impacts of this future OWF on the ecosystem structure and functioning. A food-web model and three scenarios were constructed to investigate the "reef" and "reserve" effects induced by the OWF on the ecosystem. Ecological Network Analysis indices, other ecosystem attributes and Mean Trophic Level were derived to investigate the ecosystem health and state.However, being aware that this ecosystem is threatened by multiple perturbations, there is a need to understand how human activities interact to influence ecosystem functioning in a long term climate change context. Thus, a holistic view of cumulated impacts on the Courseulles-sur-mer' ecosystem through the use of an oriented signed digraph was also developed. Results highlighted a combination of significant changes in the food-web structure and ecosystem functioning. These results can play a vital role in both decision making by improving long term planning for the marine environment but also as tool for communication with the public and so contribute to a better acceptability of MRE project. ; ans le cadre de la transition énergétique, le gouvernement Français prévoit la construction de huit parcs éoliens en mer (offshore) le long des côtes Manche-Atlantique parmi lesquels le futur parc éolien au large de Courseulles-sur-mer. A ce jour, il n'existe pas d'étude globale et intégrée des effets de la construction et de ...

As part of the energy transition, the French government is planning the construction of eight Offshore Wind Farms (OWF) along the English Channel and Atlantic coasts including the Courseulles-sur-mer OWF. Until now, there is no holistic study on the OWF construction and operation effects on an ecosystem taken as a whole. This thesis is the first study to lay the foundations for an ecosystem approach of Marine Renewable Energy (MRE) through the Courseulles-sur-mer OWF example. For that a combination of innovative modelling tools was applied to 1) characterise the ecosystem structure and functioning before the OWF construction; 2) simulate the impacts of this future OWF on the ecosystem structure and functioning. A food-web model and three scenarios were constructed to investigate the "reef" and "reserve" effects induced by the OWF on the ecosystem. Ecological Network Analysis indices, other ecosystem attributes and Mean Trophic Level were derived to investigate the ecosystem health and state.However, being aware that this ecosystem is threatened by multiple perturbations, there is a need to understand how human activities interact to influence ecosystem functioning in a long term climate change context. Thus, a holistic view of cumulated impacts on the Courseulles-sur-mer' ecosystem through the use of an oriented signed digraph was also developed. Results highlighted a combination of significant changes in the food-web structure and ecosystem functioning. These results can play a vital role in both decision making by improving long term planning for the marine environment but also as tool for communication with the public and so contribute to a better acceptability of MRE project. ; ans le cadre de la transition énergétique, le gouvernement Français prévoit la construction de huit parcs éoliens en mer (offshore) le long des côtes Manche-Atlantique parmi lesquels le futur parc éolien au large de Courseulles-sur-mer. A ce jour, il n'existe pas d'étude globale et intégrée des effets de la construction et de ...

As part of the energy transition, the French government is planning the construction of eight Offshore Wind Farms (OWF) along the English Channel and Atlantic coasts including the Courseulles-sur-mer OWF. Until now, there is no holistic study on the OWF construction and operation effects on an ecosystem taken as a whole. This thesis is the first study to lay the foundations for an ecosystem approach of Marine Renewable Energy (MRE) through the Courseulles-sur-mer OWF example. For that a combination of innovative modelling tools was applied to 1) characterise the ecosystem structure and functioning before the OWF construction; 2) simulate the impacts of this future OWF on the ecosystem structure and functioning. A food-web model and three scenarios were constructed to investigate the "reef" and "reserve" effects induced by the OWF on the ecosystem. Ecological Network Analysis indices, other ecosystem attributes and Mean Trophic Level were derived to investigate the ecosystem health and state.However, being aware that this ecosystem is threatened by multiple perturbations, there is a need to understand how human activities interact to influence ecosystem functioning in a long term climate change context. Thus, a holistic view of cumulated impacts on the Courseulles-sur-mer' ecosystem through the use of an oriented signed digraph was also developed. Results highlighted a combination of significant changes in the food-web structure and ecosystem functioning. These results can play a vital role in both decision making by improving long term planning for the marine environment but also as tool for communication with the public and so contribute to a better acceptability of MRE project. ; ans le cadre de la transition énergétique, le gouvernement Français prévoit la construction de huit parcs éoliens en mer (offshore) le long des côtes Manche-Atlantique parmi lesquels le futur parc éolien au large de Courseulles-sur-mer. A ce jour, il n'existe pas d'étude globale et intégrée des effets de la construction et de ...