Portail HAL UHA (Université de Haute-Alsace)
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Municipales 2026 : l'harmonisation des règles électorales adoptée !
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Concéder les rivières pour coloniser les terres. Le droit de pêche comme outil de développement du Canada sous le Régime français (1663-1759)
No full textInternational audienceAvec la mise en valeur agricole des terres, la pêche devait être l’un des principaux moyens de dynamiser l’économie et la démographie du Canada après sa reprise en main par le pouvoir royal (1663). Le système concessionnaire, qui s’appuie sur le régime seigneurial en vigueur et sur l’octroi gratuit de monopoles, se voulait un moyen aisé d’attirer les entrepreneurs et les habitants de la colonie à développer l’activité halieutique, promettant des bénéfices rapides au regard de l’abondance des espèces et de la diversité des débouchés. Pour cette raison, le pouvoir royal encourage activement son développement, non seulement en multipliant les concessions, mais également en soutenant matériellement et financièrement les entreprises, et en encadrant juridiquement le droit de pêche en cas de conflit. Comment s’est organisée la concession des droits de pêche au Canada français ? Pourquoi le pouvoir royal a-t-il recouru à l’instrument de la concession et avec quelle efficacité ? Le présent article entend étudier les modalités et les conséquences des différents systèmes concessionnaires instaurés directement ou indirectement par le pouvoir royal. L’objectif est de montrer pourquoi, comme beaucoup de politiques coloniales françaises en Nouvelle-France, le développement de l’activité halieutique n’a pas tout à fait eu les moyens de ses ambitions. Malgré quelques succès locaux et un soutien pérenne de la monarchie, elle s’est heurtée à de nombreux obstacles et n’occupe qu’une place mineure dans l’essor limité de la colonie française
Synthesis, Structural Investigation, and Energetic Performance Study of ZIF-25
No full textInternational audienceThe synthesis of ZIF-25 was successfully optimized by using acetic acid as a modulator agent, yielding a highly crystalline material. The product exhibits significant porosity, thermal stability up to 300 °C, and hydrophobicity, making it ideal for use in lyophobic heterogeneous systems (LHSs). Notably, the crystal structure of ZIF-25 was refined for the first time using the Rietveld method and fully reported in space group Pm-3m. Energetic performance evaluation in intrusion−extrusion experi- ments shows that the “ZIF-25−water” system dissipates mechanical energy with adsorbed and released energies of ∼15−19 and ∼10 J g−1, respectively. These features make it an LHS with shock- absorber characteristics. The study highlights that the energetic behavior of ZIFs is topology-dependent, with RHO-type ZIFs such as ZIF-25 and ZIF-71 showing shock-absorber properties, while SOD-type ZIFs (like ZIF-8) exhibit spring-like behavior. Post-experiment characterizations, performed by X-ray diffraction, nitrogen adsorption at 77 K, and scanning electron microscopy, indicate moderate and pressure-dependent degradation when the material is subjected to pressurized water intrusion
Introducing a new electron acceptor for the implementation of photocyclic initiating system for radical photopolymerization
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Influence of carrier gas on pyrolysis and gasification of wood pellets
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Physicochemical properties of carbon-based materials enhance in situ biomethanation performances under organic overload
No full textInternational audienceCarbon-based materials gained attention for their potential to improve anaerobic digestion (AD) performance.Meanwhile, in situ biomethanation, where external H2 is injected into the AD process to enhance the CH4 contentin biogas, is more subjected to process inhibition than AD while facing sudden changes in operational param-eters. This study explored the effects of carbon-based materials on a semi-continuous in situ biomethanationprocess performance and stability. Two biochars and one granular activated carbon were tested at a concen-tration of 10 g⋅L-1. The experiment was conducted in three phases: a one-week start-up phase in AD conditions,an 8-week phase of in situ biomethanation, reaching a steady state, and a 2-week overload phase performed tocreate instability during the in situ biomethanation process. All additives significantly mitigated process failureunder overload conditions, with CH4 production reaching 117 ± 16 vs 160 ± 16 NmL CH4⋅d-1 on the first week oforganic overload (control vs average of all supplemented conditions). Specifically, the use of GAC-BC, with thehighest surface area, pore volume, and diameter, led to a tenfold increase in CH4 production compared to thecontrol in the overload phase. This improvement was associated with higher archaeal diversity and dominance ofthe Bacteroidales class. Conversely, the biochars, with lower surface properties, did not enhance microbial growthor improve final VFA consumption, resulting in final VFA concentrations similar to the control (11 g COD⋅L-1).These findings highlight the importance of surface properties in additives for mitigating VFA accumulation understressed conditions during in situ biomethanation
Le paradoxe de la consommation socialement responsable sur les plateformes de livraison de repas en ligne
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Photoelectrocatalytic response of tris(2,2′-bipyridyl)ruthenium(II)-modified mesoporous silica film on ITO electrode with methyl viologen quencher and EDTA donor
No full textInternational audienceIn the present paper, we investigate the photoelectrochemical behaviour of a tris(bipyridine) derivative (denoted [Ru(bpy)2(bpy')] 2+ ) covalently immobilized in the nanochannels of a vertically aligned mesoporous silica film (VMSF) generated by electrochemically assisted self-assembly (EASA) onto a transparent indium-tin oxide (ITO) electrode, in solutions containing a quencher (methyl viologen, MV 2+ ) and a model substrate partner (ethylenediaminetetraacetate, EDTA). The optimal film loading was first determined according to its solid-state photophysical properties. Then, the electrochemically accessible [Ru(bpy)2(bpy')] 2+ moieties were exploited in the presence of the MV 2+ quencher alone in solution (aerated medium) to demonstrate the possible electrochemical regeneration of the photocatalyst immobilized in VMSF on ITO. This was achieved on the basis of experiments carried out by hydrodynamic amperometry at constant potential under successive sequential illumination (at 400 nm) and dark periods. Finally, the functionalized film was applied to the photoelectrocatalytic oxidation of EDTA in an oxygen-free solution containing also MV 2+ species, thanks to the effective electrochemical regeneration of the quencher, as also evidenced by photocurrent measurements as a function of time with successive switching of light from 'off' to 'on' and vice versa. Such photoelectrocatalytic transformation of EDTA is possible at a much lower potential (-0.1 V) than that observed for its direct electrocatalytic oxidation by the same [Ru(bpy)2(bpy')] 2+ -functionalized film operating without light (+1.2 V).</div