Portail HAL UHA (Université de Haute-Alsace)
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What does “common” mean? British Civil War Radical Sects and the Commons – The Case of the Levellers, the Diggers and the Ranters
No full textInternational audienceThis essay investigates the sectarian milieu of revolutionary England in the mid-seventeenth century and addresses the new forms of discourse concerning private property and the use of common goods that emerged in the turbulent 1640s culminating in the trial of Charles I and the regicide. It explores the writings of three Civil War radical sects – the Diggers, the Ranters and the Levellers – and brings out the views of the commons expressed in them. Studying these three radical sects through the prism of their approach to the commons helps to form a clearer picture of these dissenting groups and of their thought at a pivotal time in the history of the British Isles. The Diggers, the Ranters and the Levellers became involved in debates as to whether private property was constitutive of society or whether it could be traded for communal practices based on shared goods and resources. This chapter looks into the way each of these sects viewed the commons, before considering what their attitudes to the commons tell us about the English Revolution and deciding how valuable their contributions are to our own understanding of communality.Ce chapitre s’intéresse aux nouvelles formes de discours politique à propos de la propriété et des biens communs qui surgirent dans la sphère radicale à l’époque de la révolution anglaise du milieu du dix-septième siècle. Il prend appui sur les écrits de trois groupes radicaux – les Diggers (« Bêcheurs »), les Ranters (« Divagueurs ») et les Levellers (« Niveleurs ») – publiés dans les années 1640 et, plus particulièrement, au moment du régicide de Charles Ier en 1649, et expose la conception que ces radicaux se faisaient des communs. Dans leurs pamphlets, les Diggers, les Ranters et les Levellers interrogèrent, entre autres sujets, la nature de la propriété : était-elle constitutive de l’ordre social ou pouvait-elle être remplacée par des pratiques communalistes reposant sur le partage des biens et des richesses ? Ce chapitre met en évidence la façon dont la conception des communs telle qu’elle s’exprime dans les écrits des trois groupes radicaux étudiés nous renseigne sur ce que fut la révolution anglaise de la première moitié du dix-septième siècle. Il montre également combien ces contributions à la réflexion sur le sujet sont éclairantes quant à notre propre compréhension de la notion de communs
Modification of nanoporous filtration membranes by cold plasma polymerisation and application to heavy metals removal
No full textInternational audienceCommercial membranes often exhibit difficulties in rejecting specific ionic species, and especially multivalent cations, due to their usual negative charge. To face this drawback, it is proposed here to functionalize the membrane surface by allylamine plasma polymerization. The surface of a thin film composite membrane with polyamide active layer was modified by depositing poly(allylamine) using cold plasma polymerization. The membranes were first characterized in terms of surface charge (by zeta potential measurements) and mean pore size (by fitting neutral solute rejection curve with a steric hindrance model). Tangential filtrations of solutions containing various cationic pollutants, as well as a foulant molecule, were also conducted with both pristine and modified membranes. Zeta potential measurements show that electrical properties are strongly impacted by polly(allylamine) grafting and isoelectric point is moved towards basic pH when polymerization duration increases. This leads to a shift, from negative to positive membrane charge at natural pH = 6, induced by the positive amine groups grafted at the membrane surface. It turns out that structural properties are also impacted by grafting since the mean pore radius is halved from 2.45 to 1.32 nm and the permeability drops by almost 30% due to polymer growth in the form of a layer of nanometric beads. From filtration of multi-ionic solutions, it can be observed that the changes in membrane properties leads to a strong increase in the rejection of multivalent cations (Ba²⁺, Ni²⁺, Co²⁺ and Cr³⁺) up to 95% . Oppositely, monovalent Li+ and divalent Pb2+, which exhibit negative retentions with the pristine membrane, were weakly rejected by the modified membrane. Considering electrostatic interactions between ions and the positive charge of the modified membrane, the weak impact of modification on lithium rejection was expected, but the odd behaviour of lead is disconcerting. A specific investigation of the ion properties tends to show that usual ion properties cannot explain this behaviour. Finally, the fouling study with BSA shows that the poly(allylamine) deposition does not impact the flux decrease during filtration. However, it allows a more efficient removal of fouling deposit during membrane rinsing, which leads to a lower irreversible fouling and a slightly higher normalized flux. Commercial membrane modification by plasma polymerization appears to be a relevant approach to adjust the membrane surface properties to specific applications of ionic contaminant removal
Synthesis of Ag3PO4/g-C3N4/CuO ternary nanocomposite for photocatalytic reduction of Cr(VI) and photocatalytic degradation of Orange G dye
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Adsorption of CO, NO and NO2 with H2O and O2 on nickel-exchanged sodium X- and Y-faujasites: DFT calculation, zeolite synthesis, characterization, isotherms and dynamic experiments – Application to the exhaust diesel gases
No full textInternational audienceThis article investigates the adsorption of NO, NO2 (NOx), CO and H2O on Ni and Na exchanged Y and X zeolites (with Si/Al = 2.55 and 1.23 respectively), to limit the cold start pollutant emissions in diesel exhausts. Ni2+ exchanged Y and X zeolites were synthesized via cation exchange from NaY and NaX. Optical Emission Spec- troscopy was used to determine Ni/Al, Na/Al, and Si/Al ratios. Powder X-ray Diffraction confirmed framework crystallinity, while Brunauer–Emmett–Teller analysis and t-plot methods provided specific surface area and microporous volume, respectively. Adsorption isotherms were developed for CO, NO and H2O at 278 K, 298 K and 318 K and were fitted using the Toth model, to estimate the equilibrium constant, the saturation capacity and Henry’s constant. Adsorption enthalpies were calculated from the Clausius-Clapeyron relationship using data from the isosteres. High hysteresis was identified for NO suggesting chemisorption on Ni exchanged zeolites. Breakthrough experiments were conducted at 303 K and atmospheric pressure for gas mixtures composed of NOx, CO, O2, H2O in N2, to measure breakthrough times and dynamic adsorption capacities. Density functional theory calculations were employed to predict adsorption energies between the gases and the frameworks. The study demonstrates that NiX is the best candidate and suitable for the selective trapping of CO and NO molecules in the the presence of water and oxygen. This work is the first to integrate the density functional theory based molecular screening, targeted synthesis, and experimental validation, for the development of passive NOx adsorbers
Tableaux de bord des Organismes de gestion de destination face aux défis de l'Anthropocène : entre normes environnementales globales et logiques institutionnelles locales
No full textInternational audienceCet article explore les tensions entre les normes environnementales globales et les logiques locales des Organismes de gestion de destination (OGD) dans le contexte de l'Anthropocène. Alors que les OGD sont de plus en plus confrontées à des ambitions environnementales internationales, ils doivent aussi tenir compte des réalités et des contraintes spécifiques de leur territoire. Ces tensions se révèlent parfois dans des tableaux de bord, qui ne sont pas seulement des instruments de mesure, mais aussi des lieux de compromis et de négociation. Les résultats montrent que ces tableaux de bord, souvent perçus comme des outils techniques, deviennent des dispositifs hybrides où les normes environnementales globales sont adaptées aux logiques institutionnelles locales. Ce processus d’hybridation permet de concilier les impératifs de durabilité avec les besoins et priorités des acteurs locaux. En ce sens, les tableaux de bord jouent un rôle clé dans la maintenance institutionnelle des OGD. Ils permettent aux OGD de préserver leur légitimité et leur capacité d’action face aux enjeux écologiques tout en ajustant les exigences externes aux spécificités locales. L’étude met en lumière l’importance de repenser les outils de gestion, en particulier les tableaux de bord, pour qu’ils soient plus flexibles et collaboratifs, capables de répondre aux défis complexes et multi-échelles de l’Anthropocène. La maintenance institutionnelle devient ainsi un levier stratégique pour les OGD, leur permettant de naviguer entre les normes globales et les logiques locales, tout en légitimant leur rôle dans la transition écologique du secteur
Heteroleptic Copper(I) Complexes with Pyridine-Benzothiazole Ligands as Photocatalysts for Free Radical Photopolymerization and 3D Printing
No full textInternational audienceCopper(I) complexes have attracted considerable attention as efficient redox photocatalysts (PCs) in photopolymerization. In this study, two copper(I) complexes bearing a pyridine-benzothiazole ligand were thoroughly investigated as photocatalysts for the free radical photopolymerization of ethoxylated trimethylolpropane triacrylate under violet and green light irradiation. A threecomponent system comprising a copper complex, di-tert-butyl-diphenyl iodonium hexafluorophosphate, and ethyl dimethylaminobenzoate as additives was investigated under various conditions. The copper complexes exhibited remarkable photoinitiation capabilities, achieving high monomer conversion rates and highlighting significant structure-reactivity relationships. Based on free energy calculations and spectroscopic analyses, a mechanistic pathway was proposed. The optimal conditions were successfully applied in 3D printing, producing smooth and uniform 3D structures
L'ingénierie des esprits : Le système éducatif de l'État islamique comme dispositif totalitaire (2014-2017)
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Modèle anisotropique de marche aléatoire persistante simule la migration des cellules T sur des substrats courbés
No full textInternational audienceCell migration is an important cellular process to study, as it plays a fundamental role in tissue structuring and development, while abnormal cell migration may be the cause of certain diseases. Among the known factors influencing cell migration, substrate curvature is one, with cells naturally moving towards concave areas while avoiding convex ones. The underlying causes of migration guidance by curvature remain unclear, and in particular, the way in which cell persistence is affected is still not well understood. We introduce an anisotropic persistent random walk model which includes cell heterogeneity to simulate T-cell migration across various corrugate landscapes. We compared the trajectories generated by the model with in vitro T-cells trajectories over the same topographies. The model accurately captures key features of cell trajectories on flat surfaces as well as on curved surfaces, such as a directional bias toward concave regions. The model also reveals a superdiffusive behavior on curvature, demonstrating more efficient movement compared to flat surfaces. The anisotropic randomness incorporated in the model appears as a critical feature which shapes T-cells persistence mechanisms by increasing cellular activity in the axis of concave valleys and promoting migration towards concave areas
Innovative Elaboration of Polyvinylidene Fluoride Thin Films via Dip-Coating: Beta Phase Optimization, Humidity Control, Nanoparticles Addition, and Topographic Analysis
No full textInternational audiencePolyvinylidene fluoride (PVDF) is a multifunctional polymer renowned for its unique electrical, mechanical, and piezoelectric properties, making it an attractive candidate for various applications. Although the spin-coating method has been the conventional method for fabricating PVDF thin films, this work is the first to apply the dip-coating technique with humidity control, which is a largely unexplored method in the literature on PVDF thin films. This novel approach offers great prospects for improved control and performance adjustments, as well as expanding the range of film deposition procedures. Here, we examine the phase composition of PVDF thin films; adjust different parameters to optimize the electroactive phases fraction, especially the Beta phase; and examine how relative humidity affects the properties of the film. Moreover, we test the impact of different nanoparticles' addition on the phases fraction and characteristics of the film. Furthermore, we analyze the topography of the resultant films using several approaches, providing fresh insights into their structural features