Développement durable et agriculture durable : sens du concept de « durabilité » à travers la presse régionale et le discours des agriculteurs

Cette étude porte sur la question du sens des concepts de développement durable et d’agriculture durable à travers, d’une part, une analyse de contenu de leur diffusion dans la presse régionale (presse spécialisée en milieu agricole et presse généraliste). D’autre part, elle s’intéresse à l’appropriation de ces concepts par les agriculteurs. Pour ce faire, des entretiens semi-directifs ont été menés auprès de ces acteurs en prise avec ces questions de « durabilité ». L’objectif est de mettre en parallèle ces deux formes de contenu et de mettre en lumière les représentations sociales liées à ces objets en partant du postulat que ces dernières, en tant que forme de connaissance socialement élaborées, sont un guide pour l’action et que celles-ci se forment, se transmettent, et évoluent au cœur de la communication (Moscovici, 1976).<br>This study focuses on the meaning of the concepts of sustainable development and sustainable agriculture. First, this study deals with a content analysis of their circulation in the regional papers (specialized in agriculture and popular newspaper). Second, it is interested in the appropriation of theses concepts farmers. Semi-structured interviews were carried out with these stakeholders concerned with these issues. The aim of the study is to compare these two content analyses and to highlight the social representations of these concepts. We postulate that these representations are a form of knowledge which is socially constructed. They are a guide to action and that they take shape, they are transmitted and they evolve in the heart of communication (Moscovici, 1976)

Développement durable et agriculture durable : sens du concept de « durabilité » à travers la presse régionale et le discours des agriculteurs

This study focuses on the meaning of the concepts of sustainable development and sustainable agriculture. First, this study deals with a content analysis of their circulation in the regional papers (specialized in agriculture and popular newspaper). Second, it is interested in the appropriation of theses concepts farmers. Semi-structured interviews were carried out with these stakeholders concerned with these issues. The aim of the study is to compare these two content analyses and to highlight the social representations of these concepts. We postulate that these representations are a form of knowledge which is socially constructed. They are a guide to action and that they take shape, they are transmitted and they evolve in the heart of communication (Moscovici, 1976)

Action of a clay suspension on an Fe(0) surface under anoxic conditions: Characterization of neoformed minerals at the Fe(0)/solution and Fe(0)/atmosphere interfaces

International audienceTo better understand the reaction mechanisms involved at the Fe(0)/clay minerals interface, we investigate in the present study the reaction between an Fe(0) surface and a clay suspension extracted from the Callovo-Oxfordian claystone (COx). Batch experiments were carried out under anoxic conditions in sealed autoclave, at 90 degrees C to mimic predicted radioactive waste disposal conditions. An Fe(0) foil was introduced into the autoclave so that the lower part of the foil was immersed in the clay suspension while the upper part was contacted with the atmosphere of the experimental setup. After two months, the mineralogical deposits that precipitated at the surface of the Fe(0) foil were analyzed using multiple techniques, namely X-ray diffraction (XRD), scanning/transmission electron microscopy associated to microanalysis (SEM/TEM-EDXS), and micro-spectroscopic measurements (l-FTIR and l-Raman). Both parts of the Fe(0) foil were then shown to react: magnetite was the main resulting mineral formed at the Fe(0) surface in the atmospheric conditions whereas serpentine 1:1 phyllosilicates were the main end-products in the clay suspension. The analyses performed on the immersed part of the foil revealed a spatial heterogeneity in both serpentine cristallochemistry and morphology, with a gradient from the Fe(0) contact point toward the clay suspension. A pure Fe-Si phyllosilicate ring was observed at the direct contact point with the Fe(0) foil and a progressive incorporation of Al instead of Fe into the clay phases was identified as deposit thickness increased from the Fe(0) surface to the clay suspension. Our findings suggest that reaction mechanisms include several steps, corresponding to successive regimes depending on the availability of the main reactive elements at the Fe(0)/solution interface, namely Fe, Si and Al. Thus, our results provide new information to support the understanding of both mineral organization and composition at the clay/Fe(0) interface