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Development of Sustainable Geopolymer Binders Using Clay and Laterite from Burkina Faso with GGBFS: A Path towards Hybrid Solutions for Low-Carbon Construction
No full textInternational audienceThe reduction of carbon emissions from traditional cement materials, partic-ularly Ordinary Portland Cement (OPC), remains a critical environmentalchallenge. This study explores the potential of locally sourced clays and later-ites from Burkina Faso in the development of geopolymers as sustainable al-ternatives to conventional binders. The objective is to create geopolymers har-denable at room temperature using metakaolin derived from clay and laterite,while evaluating the influence of incorporating Ground Granulated Blast Fur-nace Slag (GGBFS) at varying levels. Different geopolymers formulations wereinvestigated: binders based solely on clay and laterite, and two enhanced with5% and 10% GGBFS, respectively. Microstructural analyses, including X-raydiffraction (XRD), mercury intrusion porosimetry, and Fourier transform in-frared spectroscopy (IRFT), were conducted to assess the stability and perfor-mance of the formulations. The results reveal the formation of amorphousmineral phases, as well as a significant improvement in mechanical strengthreaching 300% and 160% respectively for clay and laterite-based formulations,following the incorporation of 10% GGBFS, compared to formulations with-out GGBFS. In addition, a reduction in porosity of the order of 28% for clayformulations and 45% for hybrid clay/laterite formulations was observed with the addition of 10% GGBFS compared to formulations without this addition.Geopolymers based on Burkina Faso’s clay and laterite, with or withoutGGBFS, demonstrate strong potential as low-carbon alternatives to OPC
La contamination des produits alimentaires par les microplastiques
No full textMicroplastics are present in all environment compartments: air, water and soil, and have even been detected in human body, with food consumption being one of the routes of exposure. However, there is still a few studies and not all food matrices are targeted.The main objective of this thesis work is to develop research on the contamination of various foods by microplastics, in order to supplement current data. In order to meet this objective, the assessment of contamination in various beverages and meat products was a central focus of this thesis. The study on beverages focused on bottled water, non-alcoholic soft drinks (cola, iced tea, and lemonade), and alcoholic beverages (beer and wine) contained in various food packaging materials (plastic, glass, carton, box, can). The results showed contamination in all beverages and packaging, with higher levels of microplastic contamination in glass bottles. The external paint on the capsules was suspected to be the main source of contamination, as the majority of the isolated particles were identical to the color of this paint and shared the same chemical composition. The study on meat products focused on various meats (steak, ground beef, pork stir-fry, roast pork, chicken breast) from supermarket shelves and a supermarket butcher shop. Heterogeneous contamination results were observed, with meat from supermarket butchers proving to be more contaminated. The black and red polyester and cotton fibers found in these samples suggest that the contamination may have come from personal protective equipment for employees. At the same time, a unified methodology for analyzing microplastics in certain food categories (dairy products, fruits, vegetables, legumes, cereals and cereal products, sweet products) has also been developed and implemented, with the aim of harmonizing protocols and ensuring the comparability of results. Various digestion reagents such as KOH, H2O2, HNO3, and HClO4 were applied to these matrices. The impact of the protocols on the integrity of a set of polymers (nylon, polyethylene, polyester, polyvinyl chloride, and polystyrene) was then evaluated using positive controls.Les microplastiques, particules plastiques inférieur à 5 mm, sont présents dans tous les compartiments de l'environnement : l'air, l'eau et le sol. Ils ont même été détectés dans le corps humain, la consommation alimentaire étant l'une des voies d'exposition. Cependant, les études sont encore peu nombreuses et toutes les matrices alimentaires ne sont pas ciblées.L'objectif principal de ces travaux de thèse est de développer la recherche sur la contamination de divers aliments par les microplastiques, afin de compléter les données actuelles. Afin de répondre à cette objectif, l’évaluation de la contamination de divers boissons et produits carnés a constitué un axe central de cette thèse. L’étude sur les boissons a porté sur des eaux embouteillées, des boissons rafraichissantes sans alcool (cola, thé glacé et limonade) et des boissons alcoolisées (bières et vins) contenus dans divers emballages alimentaires (plastique, verre, brique, cubitainer, canette). Les résultats obtenus ont montré une contamination de toutes les boissons et dans tous les emballages, avec cependant une contamination microplastique plus importantes dans les bouteilles en verre. La peinture externe des capsules a été soupçonné d'être la principale source de contamination, car la majorité des particules isolées étaient identiques à la couleur de cette peinture et partageaient la même composition chimique. L’étude sur les produits carnés, quant à elle, porté sur diverses viandes (steak, steak haché, sauté de porc, rôti de porc, filet de poulet) provenant des rayons et d’une boucherie de supermarché. Des résultats de contamination hétérogènes ont été observés, avec les viandes provenant des bouchers de supermarché qui s'est avérée plus contaminée. Les fibres de polyesters et de coton noires et rouges trouvées dans ces échantillons suggèrent que la contamination proviendrait des équipements de protection individuelle des employés. En parallèle, l’élaboration et l’application d’une méthodologie unifiée pour l’analyse des microplastiques dans certaines catégories d'aliments (produits laitiers, fruits, légumes, légumineuses, céréales et dérivés, produits sucrés) a également été mise en place, dans le but d’harmoniser les protocoles et de garantir la comparabilité des résultats. Différents réactifs de digestion tels que le KOH, l’H2O2, l’HNO3 et l’HClO4 ont été appliqués sur ces matrices. L’impact des protocoles sur l'intégrité d'un ensemble de polymères (nylon, polyéthylène, polyester, polychlorure de vinyle et polystyrène) a ensuite été évalués à l'aide de contrôles positifs
Justice et technologie sociale chez Milton Friedman : éléments pour un néolibéralisme analytique
No full textInternational audienc
La réalité virtuelle : les atouts de l'individualisation et de l'effet Protée
No full textNational audienc
John Stuart Mill and Harriet Taylor in Dialogue: France, England, and Beyond
No full textInternational audienceThis special issue seeks to illuminate the social philosophy of John Stuart Mill by exploring its discursivity in two interconnected dimensions. On the one hand, we examine the discourses as intersubjective exchanges that shaped Mill’s intellectual trajectory, highlighting the influence of his private and public engagements on the development of his ideas. On the other, the essays collected here also consider the meta-discursive level, analyzing how different philosophical and socio-political traditions—particularly those of the Anglo-American and French intellectual spheres—have interpreted and contested these influences. By pursuing this dual line of inquiry in the duality of the socio-cultural contexts, this issue aims to illustrate the dual dialectical interplay between competing discourses and meta-discourses, a dynamic that is characteristic of any major intellectual figure’s reception and legacy.1 Mary Lyndon Shanley, “The Subjection of Women”, pp. 396-422, in John Skorrupski, ed., The Cambridge (...)2At the primary level of discursivity—Mill’s own intellectual engagements—our American contributor, Karen Adkins’ cutting-edge paper provides a compelling analysis of how his public commitments were profoundly shaped by personal and intimate conversations. She argues that these interactions enabled Mill’s public discourse to become more expansive, fluid, and exploratory, challenging the conventional distinction between the public and private spheres. Rather than viewing private discussions as distinct from philosophical discourse, Adkins presents friendship as a medium through which Mill was able to articulate ideas in a more nuanced, playful, and experimental manner. In the meantime, she avoids placing too much emphasis on the concept of “marital friendship”1, which clearly describes Mill’s relationship with his wife, Harriet Taylor.3This perspective, viewing friendship as both a public (rational) and private (emotional) bond, may also raise broader theoretical questions about the relationship between rhetoric and philosophy. While public discourse is often framed as a competitive, rational endeavor, private discourse may allow for a more flexible and affective engagement with ideas. Camille Dejardin’s paper builds on this distinction by drawing a parallel with the Socratic challenge of defending philosophy against rhetoric, highlighting the tensions within Mill’s own intellectual commitments. By illustrating how this Socratic mentality was adapted by Mill in response to utilitarianism, Dejardin positions the dynamic of learning and teaching at the heart of her argument on Mill’s lecture of Gorgias. This demonstrates that Mill’s pedagogical interpretation cannot simply be reduced to praise for an institutional form of education like mandatory public school. Instead, Mill seems to demand a form of individual existential growth (an “elevation”) that may be grounded also in intersubjective commitments such as friendship and love. The process of educating oneself to become a better person can lead to the attainment of dignity, which is understood in this context as a sort of merit or quality deemed worthy of admiration. If successful, such an individual accomplishment might be taken as a model to be followed by others
Identification du tempérament de picage chez deux souches commerciales de poules pondeuses
No full textInternational audienc
Stratégie d’influence et réputation de marque : les défis de l’expansion internationale pour Courbet
No full textInternational audienceAccording to a research report by Market Research Future (MRFR), the influencer marketing market is expected to reach US$38.2 billion by 2030, registering a CAGR of 33.20% throughout the forecast period (2022-2030). What are the specifics of influencer marketing? Why are brands increasingly incorporating this lever into their strategies? What are the risks involved? The case in point is that of Courbet, the first Place Vendôme ‘Maison’ to market synthetic diamonds on recycled gold, which has set out to conquer the Chinese Millennials. It illustrates that while the choice of an influencer is crucial to its success in the land of the dragon, it is not without danger. Managerial implications will be highlighted.Selon un rapport de recherche complet de Market Research Future (MRFR), le marché du marketing d’influence devrait atteindre 38,2 milliards de dollars US d’ici 2030, enregistrant un TCAC de 33,20 % tout au long de la période de prévision (2022-2030). Quelles sont les spécificités du marketing d’influence ? Pour quelles raisons les marques intègrent de plus en plus ce levier dans leurs stratégies ? Quels sont les risques encourus ? Le cas retenu est celui de Courbet, première Maison de la Place Vendôme à commercialiser des diamants de synthèse sur or recyclé, partie à la conquête des Milléniaux chinois. Il permet d’illustrer que, si le choix d’un influenceur est déterminant, il n’est pas pour autant sans danger pour la marque qui y recourt. Des implications managériales seront mises en lumière