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Postface « L’Éloge du fugace : le rêve et le monde de Ruike Han »: Postface à « Île en fleurs », recueil de poèmes franco-chinois composé par Ruike Han
No full textCurcumin-modified gelatin nanocomplexes as novel food foaming Agents: Impact on foamability and interfacial properties
No full textInternational audienceAlthough polyphenol modification can enhance the foaming properties of hydrophilic gelatin, the mechanisms by which polyphenols affect gelatin interfacial and foaming behavior are not well understood. In this study, hydrophobic curcumin was used to modify gelatin (Type A), forming a nanocomplex designed as a novel foaming agent. In this study, we investigated the adsorption of curcumin/gelatin nanocomplexes at the air/water interface and the resulting foaming properties. Nanocomplexes were prepared at curcumin to gelatin mass ratios of 0, 0.05, 0.1, 0.15, and 0.2. Their bulk behavior was assessed based on particle size, zeta potential, complexation efficiency, and surface hydrophobicity. As the mass ratio of curcumin to gelatin increased from 0:1 to 0.2:1, the diameter of the nanocomplexes gradually increased from 32 nm to 279 nm, whereas their negative surface charge decreased from −3.4 mV to −1.3 mV. Additionally, surface hydrophobicity increased with curcumin addition, as indicated by the amount of bound bromophenol blue sodium, which rose from 11 μg to 30 μg. The interfacial properties were evaluated using dynamic surface pressure and dilatational rheology. The presence of curcumin increased the nanocomplex surface pressure, leading to enhanced foamability. The interfacial behavior was predominantly elastic; whereas, as the curcumin concentration increased, the elastic modulus did not improve significantly, resulting in no significant enhancement in foam stability. These findings suggest that curcumin/gelatin nanocomplexes are potential excellent foaming agents to be used in food, pharmaceutical, and other industries
FNOPT: Resolution-Agnostic, Self-Supervised Cloth Simulation using Meta-Optimization with Fourier Neural Operators
No full textInternational audienceWe present FNOPT, a self-supervised cloth simulation framework that formulates time integration as an optimization problem and trains a resolution-agnostic neural optimizer parameterized by a Fourier neural operator (FNO). Prior neural simulators often rely on extensive ground truth data or sacrifice fine-scale detail, and generalize poorly across resolutions and motion patterns. In contrast, FNOPT learns to simulate physically plausible cloth dynamics and achieves stable and accurate rollouts across diverse mesh resolutions and motion patterns without retraining. Trained only on a coarse grid with physics-based losses, FNOPT generalizes to finer resolutions, capturing fine-scale wrinkles and preserving rollout stability. Extensive evaluations on a benchmark cloth simulation dataset demonstrate that FNOPT outperforms prior learning-based approaches in out-ofdistribution settings in both accuracy and robustness. These results position FNO-based meta-optimization as a compelling alternative to previous neural simulators for cloth; thus reducing the need for curated data and improving cross-resolution reliability.</div
DataLAC : intelligence artificielle dans un lac de données pour valoriser les archives archéologiques
No full textDémoNational audienceThe DataLAC project focus on the use of artificial intelligence for the alignment, annotation and interpretation of heterogeneous documents enriched with semantic metadata and aggregated within a data lake. This project seeks to digitize, unify and make accessible over thirty years of field notes (1947–1977), scientific publications, and archives related to the Iberian archaeological site of Ullastret. These diverse materials are integrated into an interoperable data lake designed to manage the heterogeneity of sources and to support complex research queries. The DataLAC project thus constitutes a generalizable proof of concept, demonstrating the potential of data lake architectures and AI-driven methodologies for the exploitation and interpretation of archaeological archives.Notre travail dans le cadre du projet DataLAC explore comment l'extraction automatisée de métadonnées depuis des carnets de fouille manuscrits, au sein d'un lac de données intégrant des sources de données hétérogènes, peut transformer l'exploitation d'archives archéologiques. En s'appuyant sur le cas du site ibérique d'Ullastret en Catalogne et ses trente années de documentation de terrain (1947-1977), le projet vise à démontrer l'apport d'un lac de données dont l'architecture comprend quatre phases : (a) numérisation des carnets manuscrits et de la documentation scientifique ; (b) transcription automatique par apprentissage automatique ; (c) extraction et modélisation des métadonnées enrichies sémantiquement ; (d) interrogation sémantique des documents et métadonnées. L'enjeu central réside dans la capacité du lac de données à réunir des sources documentaires dispersées et à en extraire automatiquement des informations structurées permettant de nouvelles formes d'analyse. DataLAC constitue ainsi une preuve de concept sur la manière dont l'intelligence artificielle appliquée à l'extraction de métadonnées peut renouveler les pratiques de recherche en archéologie, en rendant exploitables et interrogeables des corpus jusqu'alors difficiles d'accès
Le Jeune dessinateur de Jan Lievens : support d’une réflexion sur la contemporanéité éducative
No full textInternational audienceCet article propose une réflexion sur la contemporanéité de l’éducation à partir d’une analyse du tableau Le Jeune dessinateur de J. Lievens (1607-1674). En s’appuyant notamment sur les travaux de G. Agamben et H. Arendt, il envisage la peinture non comme un objet historique, mais comme un déclencheur intempestif de pensée éducative. À rebours d’une pédagogie centrée sur la transparence, la lumière et l’efficacité, l’article défend une pensée de l’ombre comme puissance éducative, valorisant la suspension, l’indétermination et l’inachèvement propres à l’atelier en tant que dispositif de formation. L’ombre, loin d’être un simple défaut de lumière, devient ici un espace de création et de profanation des usages scolaires dominants. À travers une lecture philosophique du tableau, l’article invite à penser l’éducation comme une expérience – entendue au sens de skholé – ouvrant un autre rapport au savoir, aux objets et au temps
Regioselective C-alkylation in a series of functionalized 1,2,3-triazoles: An unexpected preference over O-alkylation
No full textInternational audienceA series of novel 1,2,3-triazole derivatives were synthesized via Cu(I)-catalyzed click chemistry, introducing structural diversity at positions 1 and 4 of the triazole ring, to explore their reactivity toward alkylation. Attempts to perform O-alkylation on hydroxymethyl-substituted triazoles unexpectedly led to unreported regioselective C-alkylation at the methylene adjacent to the triazole ring. The C-alkylation was optimized using DBU and choline acetate in acetonitrile and subsequently examined across a range of alkyl and benzyl bromides to establish its scope and generality. The resulting racemic C-alkylated products were fully characterized, including confirmation of the regioselectivity by X-ray crystallography, and their enantiomers were separated by supercritical fluid chromatography. This work reveals a novel and synthetically valuable C-alkylation pathway for 1,2,3-triazoles, offering new opportunities for the development of structurally diverse and potentially bioactive triazole derivatives
Electronic structure origins of radical character in triangular fused acenes: sextet stabilization vs. antiaromaticity release
No full textInternational audienceTriangular acenes display size-dependent radical character arising from the interplay between Clar's sextet stabilization and the release of cyclobutadiene antiaromaticity
Measurement of small linear birefringences in chiral photonic devices
No full textInternational audienceWe present a straightforward and accurate method for measuring the birefringence of chiral waveguides. Due to the chiral nature of these devices, the supported modes are elliptical, enabling direct access to their linear birefringence characteristics. Consequently, determining the linear birefringence reduces to measuring the device’s Mueller matrix. This method is particularly effective when the linear birefringence is comparable in magnitude to the circular birefringence (on the order of 10−5). The technique is applied to study the impact of humidity on sol-gel-based chirowaveguides. Four distinct linear birefringence contributions are identified and measured: (1) Opto-geometrical birefringence, resulting from the waveguide geometry and modal TE/TM decomposition; (2) tensile stress-induced birefringence (∼ 10−4), linked to the waveguide fabrication process; (3) compressive stress-induced birefringence, which increases with humidity due to material swelling; and (4) residual diagonal birefringence (∼ 10−6), attributed to slight asymmetries in the rib waveguide cross-section
Backstepping for partial differential equations: A survey
No full textInternational audienceSystems modeled by partial differential equations (PDEs) are at least as ubiquitous as those by nature finite-dimensional and modeled by ordinary differential equations (ODEs). And yet, systematic and readily usable methodologies, for such a significant portion of real systems, have been historically scarce. Around the year 2000, the backstepping approach to PDE control began to offer not only a less abstract alternative to PDE control techniques replicating optimal and spectrum assignment techniques of the 1960s, but also enabled the methodologies of adaptive and nonlinear control, matured in the 1980s and 1990s, to be extended from ODEs to PDEs, allowing feedback synthesis for systems that are uncertain, nonlinear, and infinite-dimensional. The PDE backstepping literature has since grown to hundreds of papers and nearly a dozen books. This survey aims to facilitate the entry into this thriving area of overwhelming size and topical diversity. Designs of controllers and observers, for parabolic, hyperbolic, and other classes of PDEs, in one or more dimensions, with nonlinear, adaptive, sampled-data, and event-triggered extensions, are covered in the survey. The lifeblood of control are technology and physics. The survey places a particular emphasis on applications that have motivated the development of the theory and which have benefited from the theory and designs: flows, flexible structures, materials, thermal and chemically reacting dynamics, energy (from oil drilling to batteries and magnetic confinement fusion), and vehicles
A hybrid memetic metaheuristic for medical staff assignment in major public health emergencies
No full textInternational audienceDuring major public health emergencies, effective assignment of medical staff is crucial for saving lives andcontrolling the spread of epidemics. This work focuses on the assignment of doctors and nurses to hospitals toform treatment groups that carry out patient treatment tasks. We consider the practical constraints of skilltypes of medical staff and the severity of patients’ conditions and propose a mixed integer programmingmodel with the objective of maximizing demand satisfaction and personnel skill matching. To solve thisproblem, we introduce a hybrid memetic search algorithm that combines a specialized crossover operatorfor generating promising offspring solutions and a variable neighborhood search procedure to improvetheir quality. Computational results demonstrate that our algorithm outperforms the general mixed integerprogramming solver GUROBI. The key components of the proposed algorithm are experimentally analyzedand managerial insights are derived