HAL - Université de Franche-Comté
Not a member yet
51444 research outputs found
Sort by
Evaluation of a new modular system for personalised corrective surgery
No full textInternational audienceThe aim of this study is to evaluate the feasibility of using such a system under biomechanical considerations. The combined system will be screwed on a synthetic tube and subjected to compressive loading. Experimental and numerical analyses will be carried out to evaluate its performance
Elaboration of Conductive Hydrogels by 3D Printer for the Development of Strain Sensors
No full textInternational audienceThe development of biocompatible, conductive hydrogels via direct ink writing (DIW) has gained increasing attention for strain sensor applications. In this work, a hydrogel matrix composed of polyvinyl alcohol (PVA) and κ-carrageenan (KC) was formulated and enhanced with polyvinylidene fluoride (PVDF) and silver nanoparticles (AgNPs) to impart piezoelectric properties. The ink formulation was optimized to achieve shear-thinning and thixotropic recovery behavior, ensuring printability through extrusion-based 3D printing. The resulting hydrogels exhibited high water uptake (~280–300%) and retained mechanical integrity. Rheological assessments showed that increasing PVDF content improved stiffness without compromising printability. Electrical characterization demonstrated that AgNPs were essential for generating piezoelectric signals under mechanical stress, as PVDF alone was insufficient. While AgNPs did not significantly alter the crystalline phase distribution of PVDF, they enhanced conductivity and signal responsiveness. XRD and SEM-EDX analyses confirmed the presence and uneven distribution of AgNPs within the hydrogel. The optimized ink formulation (5% PVA, 0.94% KC, 6% PVDF) enabled the successful fabrication of functional sensors, highlighting the material’s strong potential for use in wearable or biomedical strain-sensing applications
Defect-Mediated Pairing and Dissociation of Strongly Correlated Electrons in Low Dimensional Lattices: The Quantum Taxi Effect
No full textWe study the quantum dynamics of a strongly correlated electron pair in a one-dimensional lattice, focusing on the occurrence of local dissociation/pairing mechanisms induced by a site energy defect. To this end, we simulate the time evolution of two interacting electrons on a finite-size chain governed by an extended Hubbard Hamiltonian including on-site Coulomb repulsion U and nearest-neighbor interaction V , along with single-electron hopping J. By introducing a local site energy defect with amplitude ∆, we show that a transition between spatially paired/dissociated electrons can occur in the vicinity of this site. Such mechanisms arise in a strongly correlated regime with non-zero nearest neighbor Coulomb interactions and under the conditions (U ∼ V ∼ ∆) ≫ J. To rationalize these phenomena, we reformulate the two-electron dynamics of the original Hubbard chain as an effective single-particle problem on a two-dimensional network. Within this framework, we show that the pairing/dissociation dynamics are driven by resonances between two distinct families of two-electron eigenstates: (i) states with two spatially well-separated electrons with one located at the site defect, and (ii) states with locally bound electron located away from the defect. At resonance, these states hybridize, allowing transitions from locally paired to dissociated electrons (and vice versa) in the vicinity of the defect. These results provide new insights into exotic pairing phenomena in strongly correlated electronic systems and may have implications for the design of tunable many-body states in low-dimensional quantum materials
« La Mettrie, le devenir matérialiste de la pensée et de la philosophie »
No full textInternational audienceLa Mettrie s’intéresse à l’histoire matérialiste du développement de la pensée dans les êtres sensibles mais il écrit aussi une histoire du matérialisme à un niveau individuel et collectif. Par l’écriture d’autoportraits en particulier, La Mettrie prend la question du devenir-matérialiste par les effets, par ce que le matérialisme nous fait. La question du devenir-pensant est surplombée par la question politique du devenir-philosophe, ou devenir-matérialiste
Evenness peaks in fire-resilient vegetation preceded ecosystem shifts in East Africa
No full textInternational audienceFire is often assumed to be a key driver in shaping tropical vegetation structure and composition in grass-dominated ecosystems, while forests experience infrequent but impactful fires that influence ecosystem resilience. Although short-term interactions between fire and vegetation are well-documented, long-term dynamics remain underexplored. This study examines fire regimes, vegetation dynamics, and its biodiversity over the past 17 000 years in southwest Tanzania, using sedimentary charcoal and pollen. Major ecological transformations of vegetation and fire regimes were recorded, with vegetation changes consistently preceded shifts in fire regimes. Increased grass pollen correlated with more frequent or larger fires, while high tree cover in Miombo woodland reduced fire activity. Interestingly, pollen evenness was a precursor to major ecological transformations as peaks preceded changes in ecosystem states. Changes in precipitation and moisture seems the major top–down drivers of these changes in vegetation and fire. Fire regimes were indirectly controlled by water availability, and vegetation exhibited resilience to fire at centennial timescales before reaching ecosystem shifts at 12 400 and 1700 cal BP. Our results emphasize the critical role of tree and grass cover in shaping fire regimes and highlight the interplay between climate, vegetation structure, and fire in East African ecosystems
Collage Hyperbare: Collage par diffusion or-or sous pression hydrostatique
No full textInternational audienc
Real-Time Weather-Aware Navigation for Enhanced Travel Safety
No full textInternational audienceReal-Time Weather-Aware Navigation for Enhanced Travel Safet
Le discours narrativisé dans un corpus de presse anglophone : entre discours rapporté et fiction journalistique
No full textInternational audienceThe aim of this paper is to analyse narrativised reported speech as a phenomenon of reporting the speech of others, within a corpus of British press dealing with the Brexit. Starting from the definition of this particular mode to report speech, examples from the corpus will illustrate the variety of effects generated to show the utterer-centered strategies of the journalist when he uses it.L’objet de cette contribution est d’analyser le discours narrativisé en tant que phénomène de report du discours d’autrui, au sein d’un corpus de presse anglophone traitant du Brexit. Partant de la définition de ce mode de report au statut particulier, des exemples issus du corpus illustreront la variété d’effets engendrés pour dégager les stratégies énonciatives du journaliste lorsqu’il en fait usage
Impacts sur la santé publique de la dynamique des populations de renards
No full textOpinion and report approved by the Expert Committee Socio-economic analysis in its plenary session on 11 May 2023 and the Expert Committee Animal health and welfare (CES SABA) in its plenary session on 06 June 2023. The French Agency for Food, Environmental and Occupational Health & Safety provides independent scientific opinions and reports. The original version of the ANSES opinion and report in French is available on the website of ANSES at https://www.anses.fr/fr/system/files/SABA2022SA0049Ra.pdf.Suggested citation: ANSES. (2023). Avis et rapport de l'Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail relatif à l'évaluation des impacts sur la santé publique de la dynamique des populations de renards (Saisine 2022-SA-0049). Maisons-Alfort: ANSES, 200 p.International audienceThe Red Fox (Vulpes vulpes) can be hunted as a game species. It may also be listed as a “species likely to cause damage” (ESOD – the acronym in French), for public health reasons among others. Conversely, benefits linked to the presence of foxes are also put forward, such as the predation of rodents carrying zoonotic agents. In this context, ANSES was asked to: (1) list the zoonoses present in France for which foxes play an epidemiological role, (2) identify other public health impacts associated with changes in fox populations, (3) explain the relative importance of the effects of changes in fox populations for humans and/or the environment, (4) analyse the feasibility of a cost‐benefit analysis (CBA) of the prevention and impacts associated with these zoonoses. In France, the fox is a source of zoonotic pathogens, with a major role for Echinococcus multilocularis, a parasite for which the fox is the main source of environmental contamination. However, reducing fox populations does not reduce the risk of transmission of E. multilocularis to humans or domestic animals, and may even have the opposite effect to the one intended. The main levers for action are those relating to exposure to environmental contamination. The fox is part of complex trophic networks, in which its specific role in regulating prey populations is impossible to determine because (i) several predators share the same prey, with a variable role for the fox among the predators, (ii) the dynamics of prey populations is also conditioned by factors other than predation. The relationship between the abundance of rodents and the risk of disease for humans has not been demonstrated either, due to the complexity of the trophic and epidemiological networks, their highly probable variability from one ecosystem to another, and the multiplicity of hosts. As a result, the data currently available does not allow any conclusions to be drawn about the epidemiological role of the fox as a predator of rodents hosting zoonotic agents. Finally, there is no public health justification for culling foxes, particularly for ESOD classification, except in the very specific and localised context of the fight against bovine tuberculosis, for which the selective culling of foxes in and around the livestock buildings of a domestic outbreak has been proposed. In addition, the expertise concluded to the feasibility of a CBA targeted at assessing the burden of alveolar echinococcosis and measures to prevent its transmission. The feasibility study shows the partial nature of a CBA targeting zoonoses, without taking into account other roles played by the fox in the ecosystem
