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Les territoires de montagne ont une place particulière dans la transition énergétique, à la fois pour leur sensibilité au changement climatique et pour les ressources qu’elles renferment. La configuration géographique des territoires isolés leur donne un rôle clé dans le développement de solutions énergétiques déconnectées et une autonomie fondée sur le développement d’énergies renouvelables et de dispositifs de stockage efficaces. Ces sites permettent d’analyser les matérialités de ces solutions, les motivations qui les sous-tendent et de questionner la dépendance aux lieux et au sentier socio-technique fondé sur les réseaux électriques. Cet article interroge les matérialités énergétiques dans les sites isolés de montagne des Alpes. Il questionne les modalités de la (dé)connexion ainsi que leurs motivations par une approche multiscalaire, de l’échelle du bâtiment, à celle des hameaux d’altitude jusqu’à l’intégration de vallées. Cette analyse informe plus largement les matérialités de l’isolement dans la transition énergétique, créant des espaces catalyseurs d’innovations et d’expérimentation d’une transition fondée sur un modèle énergétique, sobre, efficace et décentralisé. Mountain territories have a special role in the energy transition, because of their sensitivity to climate change and for the natural resources they contain. The geographical configuration of isolated territories gives them a key role in the development of disconnected energy solutions, through autonomous and renewable ones. These sites enable the study of the solutions’ materiality and authorizes questioning the place dependence and the socio-technical path based on electrical networks. This article aims at exploring the energy materialities in isolated mountain sites in the Alps. It questions the modalities of (de)connection as well as their motivations through a multiscalar approach, from the buildings, to high altitude hamlets, and to the integration of valleys. This analysis informs more broadly the materialities of isolation in the energy transition, creating catalytic spaces for innovation and experimentation of a transition based on a sober, efficient and decentralized energy model.

Les territoires de montagne ont une place particulière dans la transition énergétique, à la fois pour leur sensibilité au changement climatique et pour les ressources qu’elles renferment. La configuration géographique des territoires isolés leur donne un rôle clé dans le développement de solutions énergétiques déconnectées et une autonomie fondée sur le développement d’énergies renouvelables et de dispositifs de stockage efficaces. Ces sites permettent d’analyser les matérialités de ces solutions, les motivations qui les sous-tendent et de questionner la dépendance aux lieux et au sentier socio-technique fondé sur les réseaux électriques. Cet article interroge les matérialités énergétiques dans les sites isolés de montagne des Alpes. Il questionne les modalités de la (dé)connexion ainsi que leurs motivations par une approche multiscalaire, de l’échelle du bâtiment, à celle des hameaux d’altitude jusqu’à l’intégration de vallées. Cette analyse informe plus largement les matérialités de l’isolement dans la transition énergétique, créant des espaces catalyseurs d’innovations et d’expérimentation d’une transition fondée sur un modèle énergétique, sobre, efficace et décentralisé. Mountain territories have a special role in the energy transition, because of their sensitivity to climate change and for the natural resources they contain. The geographical configuration of isolated territories gives them a key role in the development of disconnected energy solutions, through autonomous and renewable ones. These sites enable the study of the solutions’ materiality and authorises questioning the place dependence and the socio-technical path based on electrical networks. This article aims at exploring the energy materialities in isolated mountain sites in the Alps. It questions the modalities of (de)connection as well as their motivations through a multiscalar approach, from the buildings, to high altitude hamlets, and to the integration of valleys. This analysis informs more broadly the materialities of isolation in the energy transition, creating catalytic spaces for innovation and experimentation of a transition based on a sober, efficient and decentralised energy model.

Mountain territories have a special role in the energy transition, because of their sensitivity to climate change and for the natural resources they contain. The geographical configuration of isolated territories gives them a key role in the development of disconnected energy solutions, through autonomous and renewable ones. These sites enable the study of the solutions’ materiality and authorizes questioning the place dependence and the socio-technical path based on electrical networks. This article aims at exploring the energy materialities in isolated mountain sites in the Alps. It questions the modalities of (de)connection as well as their motivations through a multiscalar approach, from the buildings, to high altitude hamlets, and to the integration of valleys. This analysis informs more broadly the materialities of isolation in the energy transition, creating catalytic spaces for innovation and experimentation of a transition based on a sober, efficient and decentralized energy model.

Mountain territories have a special role in the energy transition, because of their sensitivity to climate change and for the natural resources they contain. The geographical configuration of isolated territories gives them a key role in the development of disconnected energy solutions, through autonomous and renewable ones. These sites enable the study of the solutions’ materiality and authorises questioning the place dependence and the socio-technical path based on electrical networks. This article aims at exploring the energy materialities in isolated mountain sites in the Alps. It questions the modalities of (de)connection as well as their motivations through a multiscalar approach, from the buildings, to high altitude hamlets, and to the integration of valleys. This analysis informs more broadly the materialities of isolation in the energy transition, creating catalytic spaces for innovation and experimentation of a transition based on a sober, efficient and decentralised energy model.

Chloranthus serratus is a traditional Chinese medicine for treating arthritis and bruises. The aim of the present study was to investigate the anti-arthritic activities and possible associated mechanisms of different isolated sites of Chloranthus serratus (DISC) in adjuvant-induced arthritis (AA) rats. The therapeutic effects of the extracts were assessed through changes in body weights, swelling rates, arthritis indexes (AI) and organ indexes. The levels of nitric oxide (NO), malondialdehyde and superoxide dismutase were determined using one-step method, TBA method and hydroxylamine method, respectively; the levels of TNF-α, IL-1β, IL-6, prostaglandin E2, macrophage inhibitor factor-1, VEGF, immunoglobulin (Ig) G, IgM and IFN-γ in serum were determined using ELISA. Pathological changes and positive expression of VEGF in the ankle joints were investigated using hematoxylin-eosin staining and immunohistochemical staining, respectively. DISC treatment increased the weight gains and thymus indexes, and decreased the swelling rates, spleen indexes and AI in AA rats. The water isolated site (WA) and ethyl acetate isolated site (EA) significantly reversed complete Freund's adjuvant (CFA)-induced changes in the levels of NO, IL-6, TNF-α, IgG and IFN-γ, while the n-butanol isolated site (NB) only reversed the changes in IL-6 and IgG contents. Some changes in the chloroform isolated site group showed the same trend as those in the model group. The extracts relieved synovial hyperplasia, inflammatory cell infiltration and articular surface defects, and reduced the positive expression rate of VEGF in the synovial tissues of the AA rats to varying degrees. The WA exhibited the most marked effects, followed by the EA and NB, indicating that WA had optimal therapeutic effects on CFA-induced arthritic rats, which may be mediated by the oxidative stress and inhibition of inflammatory factors. C. serratus may serve as a potential candidate for the treatment of rheumatoid arthritis.

The nature of isolated tungsten oxide (WOx) sites in the dispersed phase on the surface of a β-cristobalite (β-SiO2) support in undoped and Na-or Mn-doped WOx/SiO2 model catalysts used for the oxidative coupling of methane (OCM) has not been explored previously. This work provides a computational model for isolated surface WOx sites (doped and undoped) supported on β-cristobalite (β-SiO2) and computationally explores their molecular structure, degree of hydration, and energetics over a wide range of OCM-relevant temperatures from 500 to 1300 K. Ab initio thermodynamic analysis showed that the most stable molecular configuration of the surface sites in all cases (WOx, Na-WOx, Mn-WOx) was the digrafted, dioxo pseudotetrahedral WO4. The thermal stability of the surface WO4 sites was in the order Na-WO4 ≫ WO4 > Mn-WO4 in the OCM-relevant temperature range of 850-1300 K. A spin analysis of an Mn-WO4 isolated surface site indicates a paramagnetic high-spin Mn2+-O-W6+ electronic state, in line with literature reports. The computed frequencies for isolated surface WO4 sites agree well with the experimental in situ Raman spectra of the corresponding model catalysts, proving their existence. Finally, steady-state OCM studies showed that the C2 selectivity was highest for Na-WO4 sites, followed by Mn-WO4 and WO4, a trend mimicking the degree of distortion in the molecular geometry of each site. Na-WO4 exhibited the lowest reactivity toward CH4 and the highest degree of Wâ• O bond elongation.

The nature of isolated tungsten oxide (WOx) sites in the dispersed phase on the surface of a β-cristobalite (β-SiO2) support in undoped and Na-or Mn-doped WOx/SiO2 model catalysts used for the oxidative coupling of methane (OCM) has not been explored previously. This work provides a computational model for isolated surface WOx sites (doped and undoped) supported on β-cristobalite (β-SiO2) and computationally explores their molecular structure, degree of hydration, and energetics over a wide range of OCM-relevant temperatures from 500 to 1300 K. Ab initio thermodynamic analysis showed that the most stable molecular configuration of the surface sites in all cases (WOx, Na-WOx, Mn-WOx) was the digrafted, dioxo pseudotetrahedral WO4. The thermal stability of the surface WO4 sites was in the order Na-WO4 ≫ WO4 > Mn-WO4 in the OCM-relevant temperature range of 850-1300 K. A spin analysis of an Mn-WO4 isolated surface site indicates a paramagnetic high-spin Mn2+-O-W6+ electronic state, in line with literature reports. The computed frequencies for isolated surface WO4 sites agree well with the experimental in situ Raman spectra of the corresponding model catalysts, proving their existence. Finally, steady-state OCM studies showed that the C2 selectivity was highest for Na-WO4 sites, followed by Mn-WO4 and WO4, a trend mimicking the degree of distortion in the molecular geometry of each site. Na-WO4 exhibited the lowest reactivity toward CH4 and the highest degree of Wâ• O bond elongation.

This research presents a kinetic investigation of the selective oxidation of propane to acrylic acid over a MoVTeNb oxide (M1 phase) catalyst. The paper contains both an overview of the related literature, and original results with a focus on kinetic aspects. Two types of kinetic experiments were performed in a plug flow reactor, observing (i) steady-state conditions (partial pressure variations) and (ii) the catalyst evolution as a function of time-on-stream. For this, the catalyst was treated in reducing atmosphere, before re-oxidising it. These observations in long term behaviour were used to distinguish different catalytic routes, namely for the formation of propene, acetic acid, acrylic acid, carbon monoxide and carbon dioxide. A partial carbon balance was introduced, which is a &lsquo, kinetic fingerprint&rsquo, that distinguishes one type of active site from another. Furthermore, an &lsquo, active site&rsquo, was found to consist of one or more &lsquo, active centres&rsquo, A rational mechanism was developed based on the theory of graphs and includes two time scales belonging to (i) the catalytic cycle and (ii) the catalyst evolution. Several different types of active sites exist, at least as many, as kinetically independent product molecules are formed over a catalyst surface.

The energy crisis characterized by the oil products price rising and the imperatives of sustainable development do that renewable energies are an alternative today witch attract the interest of several research teams. Senegal, sub-Saharan country, not oil producer is not spared by this crisis. The consequence of this is a low coverage of the country (especially rural areas) by the national grid. For solving this, the new orientation of the energy policy focuses on the use of renewable energy particularly solar and wind.The main objective of this thesis is to identify a methodology of design of an isolated site of electrical energy production from alternative energies It is consists on, from site characteristics (energy resources, energy requirements):- to develop an approach that allows the choice of network architecture and sizing optimally all components of the network (machines, sources and storage devices) taking into account all the constraints- to design a device for controlling components and managing the energy flowsThis thesis contains three chapters:- Chapter 1 - poses the problem of energy in Senegal. The institutional organization of the electricity sub-sector and the ongoing projects are presented. Also, a study of micro- architectures networks is made.- Chapter 2 deals with tools and software. A comparative study of the main software of analysis, design and simulation of micro- network is realized. The components of our system have been modeled. Optimization methods and tools for graphical representation (Bond Graph, GIC and EMR) systems were presented. A survey and a literature review allowed us to evaluate the energy potential of the site and the needs of populations.- Chapter 3: This is the application of our tool on an isolated site identified in Senegal (MBoro / Mer). Optimization through the Annualized Cost of the System (ACS) objective function has allowed us to scale our system optimally. As the control system with Energetic Macroscopic Representation (EMR) has been designed.For further work should be considered a treatment of problems of availability of the system through monitoring and supervision of the system. The socio- economic component is also integrated in the future to meet the changing needs and habits of the population., La crise énergétique marquée par une flambée des prix du pétrole et les impératifs d’un développement durable font des énergies renouvelables une alternative qui suscitent aujourd'hui l’intérêt de plusieurs équipes de recherches. Le Sénégal, pays subsaharien, non producteur de pétrole n’est pas épargné par cette crise. Celle-ci se traduit par, une faible couverture du pays (en particulier les zones rurales) par le réseau électrique national. Pour faire face à cela, la nouvelle orientation en matière de politique énergétique met l’accent sur l’utilisation des énergies renouvelables notamment, le solaire et l’éolienne. L'objectif principal de cette thèse est de dégager une méthodologie de conception d’un site isolé de production d’énergie électrique à partir des énergies alternatives. Il s'agit à partir des caractéristiques d’un site (ressources d’énergie disponibles, besoins énergétiques) de :- mettre en place une démarche qui permette le choix d’une architecture du réseau et de dimensionner de façon optimale l’ensemble des constituants du réseau (machines, sources et dispositifs de stockage) en tenant compte de toutes les contraintes- concevoir un dispositif de commande des composantes et de gestion des flux d’énergie Cette thèse comprend trois chapitres :- Chapitre 1 : pose la problématique de l’énergie au Sénégal. L’organisation institutionnelle du sous-secteur de l’électricité, les réalisations et les projets en cours sont présentés. Aussi, une étude sur les architectures de micro-réseaux est faite. - Chapitre 2 : traite des outils et logiciels. Une étude comparative des principaux logiciels d’analyse, de conception et simulation des micro-réseaux est réalisée. L’ensemble des composants de notre système ont été modélisées. Les méthodes d’optimisation et des outils de représentation graphique (Bond Graph, GIC et REM) des systèmes ont été présentés. Une enquête menée et une recherche bibliographique nous ont permis d’évaluer le potentiel énergétique du site et les besoins des populations.- Chapitre 3 : il s’agit de l’application de notre outil sur un site isolé identifié au Sénégal (MBoro/Mer). L’optimisation à travers la fonction objectif coût annualisée du système (ACS) nous a permis de dimensionner de façon optimale notre système. Aussi la commande du système avec la Représentation Energétique Macroscopique (REM) a été conçue.Pour la suite du travail, il faudrait envisager une prise en charge des problèmes de disponibilité du système à travers une surveillance et une supervision du dispositif. Le volet socio-économique aussi est à intégrer dans le futur afin de satisfaire l’évolution des besoins et des habitudes des populations.