Developement of a dislocation-based constitutive law for fcc crystal on a wide range of deformation amplitude

International audienceAn original description for crystal plasticity is presented in this work. It is built on a reduced set of constitutive laws whose writing is fully based on physical mechanisms responsible for plasticity in fcc crystal. Dislocation microstructures and their effect on the macroscopic behavior have been studied using 3D Dislocation Dynamics simulations. The result is a model that introduces both isotropic hardening and kinematic hardening without using any phenomenological consideration. Remarkable results are obtained in a wide range of imposed plastic strain amplitude (from small amplitude cyclic loading (10-5) to large strain monotonic loading)

9 - Mesures agro-environnementales et paiements pour services environnementaux

Les mesures agro-environnementales ont été introduites comme mesures d’accompagnement de la réforme de la politique agricole commune de 1992. Cette réforme a profondément modifié la politique européenne de soutien à l’agriculture : des aides directes aux agriculteurs ont été instaurées à la place du soutien des prix. En coupant le lien entre le montant des aides reçues par un agriculteur et ses rendements, ceci a limité les ..

La gestion du changement institutionnel en matière d'épandage agricole des boues d'épuration en France

"Independent Organizations" (IO) are an institutional change promoted by the french government to manage in a better the spreading in agriculture of sewage sludge from urban areas. It is shown that the emergence of such an institutional change, throughout a territory depends on both exogenous and endogenous factors. Two complementary approaches have been used: a quantitative first phase at a national scale, a second phase which is based on four case studies (departments: Ain, Haut-Rhin, Haute-Garonne, Aveyron) characterized by a variety of agricultural contexts, rural-urban linkages and water agencies. Exogenous factors including political decisions result in a supra-territorial, national and European levels. National water agencies exert indeed an important role in the setting-up of IO in two different ways: the strategy adopted by the agency or agencies involved in the water department and geographical location department covered by one, two or three water agencies. This phenomenon can be described as an induced institutional change, embodied in the ability of local action within specific territories such as learning effects resulting from past experiences nearby. The territorial coordination built under specification of agricultural and urban-rural relations represents a major endogenous explanatory factor. The activation process specific resources can play on two determinants of coordination between actors: the registers of the organizational and institutional coordination. Departmental case studies have confirmed that the vast diversity of local situations (especially in departments) in terms of the emergence of institutional innovations related to sludge management is explained well in the double pressure of endogenous and exogenous factors

Émergence de la notion de service environnemental et des dispositifs de rémunération des fournisseurs: le cas du Cambodge

The definition of environmental policies in developing countries is affected by globalization of such issues and the change in governments’ interventions. Based on regulatory approaches for ages, environmental policy tends nowadays to promote more incentive tools called market-bases instruments.This article aims at illustrating the trend in Cambodia from data field surveys conducted in 2010 with a sample of local stakeholders: policy makers, NGO officers and donors. The objective is to understand the emergence of the pair of notions eco-system services (ES) and payment for environmental services (PES) in conservation policies implemented in the country (areas of biodiversity and carbon sequestration mainly) and international influence in this process.The paper shows that the initial conservation strategies based on regulatory approaches with the establishment of protected areas, have had mixed success in particular to reduce deforestation. Over the recent years, the concept of SE has been quickly circulated within government offices (Forestry Administration, Ministry of Environment). Number of conservation projects conducted by international NGOs (such as CI, WCS) has also sought to recognize the value of protected ecosystems. In this objective, they have experienced payment devices to rural/forest communities sitting on environmentally-friendly practices related to the conservation of fragile habitats. Cambodian legal framework has not yet recognized, so far, the concept of PES (based on the beneficiary pays principle) and significant obstacles remain in the development of such mechanisms on a large scale

The emergence of the Biodiversity/Health nexus: making biodiversity a health issue

International audienceAbstractBefore the COVID-19 pandemic, a French epistemic community has forged and promoted a Biodiversity/Health nexus, which legitimizes biodiversity as a health issue. The relationship between biodiversity and health is now part of French local government agendas, after being included in new international programs. Based on observation of this nexus’s epistemic community and 35 semi-structured interviews conducted in France between 2017 and 2020, this article aims to show which actors and groups have been forging and promoting this nexus, and to understand how such an emergent environmental nexus challenges the governance of the present biomedical- and technical expertise-based health system. This article discusses environmental nexus from the perspective of building a new cause by reconstituting chains of causality to “demonstrate” the new problem (Barthe, Politix, 23(91), 77–102, 2010), and the growing importance of integration of concepts as a new ideal of policy-making (Cairns & Krzywoszynska, Environmental Science and Policy, 64, 164–170, 2016). As well as a justification (Boltanski & Thevenot, 1991) of their effectiveness in legitimizing the cause of defending biodiversity, environmental nexuses contain a challenge to recognize knowledge, calling for a change in governance methods in a One Health approach

The conditions of emergence of cooperation to prevent the risk of diffuse pollution from agriculture: a case study comparison from France

International audienceGroundwater resources are essential for the supply of drinking water in the European Union but significant uncertainties surround their quality. In this context, our article analyzes the factors that influence the cooperation of key stakeholders to prevent the risk of diffuse pollution from agriculture. We built on the institutional rational choice approach and the social-ecological system framework to design our analytical framework and hypotheses. We applied this analytical framework to two cases of cooperation involving drinking water suppliers and farmers in the management of the risk of non-point source pollution from agriculture in France. Our results show that cooperation emerges when the water resource is important for water suppliers to take on the leadership. Our results also characterize the role played by uncertainties and risk in getting stakeholders involved, and finally, suggest that cooperation depends on the size and predictability of the resource system

Fatigue à faible amplitude dans l'acier 316L : étude en dynamique des dislocations

National audienc

Analyse exploratoire de quelques stratégies de fourniture ‘non publique’ des biens ‘publics’

Le caractère ‘collectif’ de certains biens et services a souvent légitimé, parfois indûment, l’intervention de la ‘main visible’ de l’Etat. L’économie néo-institutionnelle initiée par Coase conteste cette vision en interrogeant la nature même des biens et en resituant le débat sur le terrain de l’efficience économique. Prenant acte, nous définissons le concept de bien en référence à son mode de financement, de production et d’accès, ce qui fait apparaître son caractère construit. L’approche coasienne cherche, dans une perspective comparative, à identifier les arrangements institutionnels réels susceptibles de minimiser l’ensemble des coûts de production et de transaction. Une telle approche n’aboutit pas nécessairement à la négation de l’intervention étatique, mais plutôt à une redéfinition des modalités de son intervention afin de permettre la réalisation des bénéfices propres aux arrangements privés. La mobilisation de la grille d’analyse de l’économie des coûts de transaction nous permet de mettre en évidence la diversité des arrangements possibles sur un continuum allant du ‘tout-Etat’ au ‘tout-marché’. Nous étudions trois arrangements institutionnels susceptibles d’aboutir à la production non publique stricto sensu de biens publics d’environnement : l’association de bénéfices privés, l’organisation collective, la contractualisation. Les modalités d’implication des pouvoirs publics sont mentionnées, en insistant sur le degré de mixité des arrangements institutionnels. Les exemples évoqués concernent essentiellement le secteur agricole, où la nature collective de certaines productions environnementales a considérablement servi à justifier l’intervention de l’Etat

Analyse exploratoire de quelques stratégies de fourniture ‘non publique’ des biens ‘publics’

The ‘ non-public’ provision of ‘ public’ goods : an exploratory analysis The ‘ public’ or ‘ collective’ nature of some goods and services has often legitimated the intervention of the ‘ visible hand’ of the state. The new institutional economics, initiated by Coase, raises objections against this rationale. First, several heterodox authors question the nature of goods and they show that the ‘ public or private nature’ is socially constructed at several stages, i. e. financing, production and access. Consequently, economics implications resulting from this distinction are seriously contested. Second, Coase and his followers challenge the public goods rationale for government production based on economic efficiency grounds. The new institutional economics proposes to identify, in a comparative way, the real institutional arrangements likely to minimize the whole production and transaction costs. Coasean economics does not mean the absence of state intervention, but rather redefines the modalities of this intervention, to enable the achievement of benefits proper to private arrangements. Government intervention does not necessarily imply that public authorities will deal with all the aspects that can be distinguished in the provision of ‘ public’ goods. Transaction costs economics show the diversity of arrangements that may emerge on a continuum ranging from the ‘ all-state’ to the ‘ all-market’ approach. We study three institutional arrangements likely to lead to non-public provision of public goods : the association of private benefits, collective organization and contractualisation. We analyze the modalities of public intervention and stress the degree of mixing in institutional arrangements. Some examples are presented, mainly in the agricultural sector, where the ‘ collective’ nature of some environmental productions has considerably justified the ‘ heavy’ intervention of the state.Le caractère ‘ collectif’ de certains biens et services a souvent légitimé, parfois indûment, l’intervention de la ‘ main visible’ de l’Etat. L’économie néo-institutionnelle initiée par Coase conteste cette vision en interrogeant la nature même des biens et en resituant le débat sur le terrain de l’efficience économique. Prenant acte, nous définissons le concept de bien en référence à son mode de financement, de production et d’accès, ce qui fait apparaître son caractère construit. L’approche coasienne cherche, dans une perspective comparative, à identifier les arrangements institutionnels réels susceptibles de minimiser l’ensemble des coûts de production et de transaction. Une telle approche n’aboutit pas nécessairement à la négation de l’intervention étatique, mais plutôt à une redéfinition des modalités de son intervention afin de permettre la réalisation des bénéfices propres aux arrangements privés. La mobilisation de la grille d’analyse de l’économie des coûts de transaction nous permet de mettre en évidence la diversité des arrangements possibles sur un continuum allant du ‘ tout-Etat’ au ‘ tout-marché’. Nous étudions trois arrangements institutionnels susceptibles d’aboutir à la production non publique stricto sensu de biens publics d’environnement : l’association de bénéfices privés, l’organisation collective, la contractualisation. Les modalités d’implication des pouvoirs publics sont mentionnées, en insistant sur le degré de mixité des arrangements institutionnels. Les exemples évoqués concernent essentiellement le secteur agricole, où la nature collective de certaines productions environnementales a considérablement servi à justifier l’intervention de l’Etat.Déprés Christophe, Grolleau Gilles, Mzoughi Naoufel. Analyse exploratoire de quelques stratégies de fourniture ‘non publique’ des biens ‘publics’. In: Cahiers d'Economie et sociologie rurales, N°74, 1er trimestre 2005. Normes et marchés : le cas de la viande (XVIIIe-XXe siècles) pp. 27-45