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Multidisciplinary science funding is more than ever a planetary priority: reflections from the Make Our Planet Great Again (MOPGA) program
No full textInternational audienceGlobal change poses “wicked problems” that have become ever more complex, pervasive, and damaging. Developing innovative solutions increasingly require diverse research approaches. The Franco-German Make Our Planet Great Again (MOPGA) program was designed to create a unique international network of top-level research, from fundamental to solution-oriented projects. MOPGA stands out from other large research initiatives by focusing not on a singular central research challenge but on facilitating multidisciplinary interactions between traditionally separated fields. MOPGA recognized that social, natural and engineering sciences share a unifying aim to address global change. In addition to addressing timely and innovative research questions within disciplines, MOPGA worked to improve communication across disciplines via annual meetings for all laureates and their research groups, scientific board exchanges, and public online seminars. Drawing on our MOPGA experiences, we discuss how such exchanges should be extended to meet the needs identified by the scientific community, international policy-makers, and regional stakeholders. In the current political landscape of scientific suppression and heightened mistrust in scientific expertise, the need for such bold, independent and collaborative scientific initiatives is greater than ever
Advancing Holonic Systems in the Era of Artificial Intelligence and Digital Twins for Trustworthy and Effective Human-Centric Intelligent Systems
No full textInternational audienceHolonic systems provide a powerful paradigm for modeling complex, distributed, and autonomous systems. However, their deployment in large-scale, heterogeneous environments raises challenges related to coordination, semantic alignment, bias migration, ethical reasoning, and real-time adaptation. This paper extends classical holonic architectures by introducing five complementary holon dimensions: effective, understanding, unbiased, vigilant, and ethical holons. Each dimension targets a specific capability required for resilient and socially responsible system behavior. These capabilities range from sustainability-aware decision-making and contextual understanding to bias mitigation and situation awareness. To enable coherent operation across autonomous and heterogeneous holons, this paper proposes to integrate federated interoperability as a foundational architectural principle. A dedicated federated interoperability holon (FIH) is proposed to dynamically manage technical and semantic interoperability. It also supports on-the-fly ontology alignment through short-lived ontologies as well as orchestrates coordination among specialized holons without centralized control. The framework is analyzed through a holon-based simulation approach, where holons act as autonomous simulation entities and are instantiated as High Level Architecture (HLA) federates. The applicability of the proposed framework is illustrated through a rural mobility use case focused on transportation systems. In this scenario, holonic coordination supports decision-making regarding multimodal integration, routing strategies, and the identification of mobility deserts. Overall, this work advances holonic system design by proposing an integration of specialized holon roles with federated interoperability mechanisms. It provides a scalable foundation for adaptive and socially aligned systems in domains such as mobility, smart territories, and enterprise ecosystems
Selective mechanochemical conversion of post-consumer polyethylene terephthalate waste into hcp and fcu UiO-66 metal–organic frameworks
No full textInternational audienceSingle-use plastics strongly contribute to plastic pollution, and less than 10% of plastic waste is recycled globally. Here, we present a selective mechanochemical protocol for converting post-consumer polyethylene terephthalate (PET) transparent bottles and coloured textile waste into the porous metal–organic framework (MOF) UiO-66 materials. We used time-resolved in situ (TRIS) synchrotron powder X-ray diffraction and Raman spectroscopy to monitor the depolymerization of PET during ball milling. To convert disodium terephthalate to UiO-66, we developed base and base-free synthetic routes that lead to fcu and hcp UiO-66 phases, respectively, including the first ever synthesis of hcp UiO-66 by mechanochemistry. Our results demonstrate the potential of mechanochemistry to selectively access fcu and hcp UiO-66 phases using post-consumer PET waste
Residual stresses and strains during laser assisted tape placement of thermoplastic composite: Multi-physical modelling and experimental validation
No full textInternational audienceThe prediction of residual stresses and strains during laser-assisted tape placement of thermoplastic composite has been investigated by numerous studies in the literature. They are however rarely validated compared to experimental results and based on simplifications of the material thermomechanical behaviour. This study proposes a multi-physical model to address the heat transfer, crystallization kinetics, the induced thermal and crystallization strains as well as the mechanical behaviour of the material during processing. The thermal and crystallization models were already validated in a previous study, and the mechanical behaviour is described with an incremental linear elastic constitutive law and the Classical Lamination Theory. The thermomechanical properties are based on values from the literature and the supplied datasheet. Without any fine tuning of the model, predicted curvatures of cross ply laminates are well described, as well as their evolution with the temperature after manufacturing and during annealing. The measured and calculated curvatures are found in excellent agreement with errors comprised between 2% and 13%. A sensitivity analysis demonstrates that the developed model is more able to correctly reproduce the experimentally observed material behaviour compared to simplified approaches found in the literature
Intensification of a continuous powder mixing process by distributed and/or delayed feeding
No full textInternational audienceIntensification of the continuous powder mixing process is intended to limit the effects of segregation, such as poor mixture homogeneity and long transient phases. Process intensification has mainly been developed for fluid processes, for example with staged or distributed feeding. In this work, we study the impact of distributed feeding of a segregating component along the entire length of a lab-scale continuous powder mixer. For this, a specificdevice is developed and tested for different feed configurations. We show that starting one of the feeders a few tenths of seconds after the beginning of the experiment reduces the mass of mixture produced during the transient regime at start-up. When using the optimal time delay, this mass is always lower than that obtained with conventional feeding. The feed configuration and the time delay of a feeder also have an impact on the homogeneity of the mixture at steady-state, due to the mixing and segregation mechanisms at play during process start-up
Micro-Tapered-Tubes Flow Analysis via DSMC and Experimental Methods
No full textInternational audienceAbstract A numerical and experimental analysis was performed on pressure-driven flows through micro-tapered tubes, which were fabricated using Two-Photon Polymerization additive manufacturing. Special emphasis was placed on the crucial role of uncertainties associated with the geometric size characterization. The constant volume technique was employed for experimental characterization, and nitrogen was used as the working gas. The DSMC method was utilized for the numerical part. The mass flow rate results show a good agreement between experiments and DSMC, within the numerical and experimental uncertainties. This study highlights the importance of DSMC as an effective tool for flow characterization in 3D microscale structures and of the TPP as a novel manufacturing technique for complex microfluidic devices working with rarefied gas flows
Approche Heuristique pour un Partitionnement Territorial Équilibré, Compact et Contigu.
No full textInternational audienceApproche Heuristique pour un Partitionnement Territorial Équilibré, Compact et Contigu
Lumped and distributed activation energy modelling of biomass pyrolysis
No full textInternational audienceThe Distributed Activation Energy Model (DAEM) is applied to a semi-detailed degradation scheme, demonstrating its effectiveness in describing the complex kinetics of biomass pyrolysis. DAEM is a widely used tool for modelling the complex reaction rates and capturing the heterogeneous nature of lignocellulosic decomposition. First, the review provides the theoretical background to DAEM, highlighting its statistical basis and the assumptions underlying the distribution of activation energies. It then analyses advances in parameter estimation, numerical methods, and optimisation techniques that improve the reliability of DAEM fitting. Comparative studies with the constant activation energy model has been considered to clarify the strengths and limitations of DAEM. A significant part of the research paper summarises how DAEM has been applied to the main constituents of biomass: cellulose, hemicelluloses, and lignins. The model was validated using external data that was not used in the fitting procedure. Applications to real biomass has been discussed alongside recent efforts to extend the model to secondary reactions and gas formation. Finally, the study explores ways to extend DAEM towards more mechanistic degradation schemes by incorporating secondary reactions and pathways that lead to gas formation and levoglucosan degradation
Experimental measurements of acetone diffusion coefficients in gas mixtures by molecular tagging
No full textInternational audienc
Upcycling waste paper into carbon dot; AgI composites for efficient pesticide degradation
No full textInternational audienceOrganic pesticides are persistent pollutants that accumulate in the environment, posing serious risks to eco-systems and human health, particularly through contamination of water resources. Photocatalytic degradation offers a sustainable and efficient approach for eliminating these pesticides, providing a green solution for environmental remediation. In this study, we report a sustainable, eco-friendly approach to synthesizing carbon dots (CDs) from waste paper and incorporating them into silver iodide (AgI) to form highly efficient visible-light photocatalyst composites. The CDs, derived from waste paper, offer advantages of low cost, low toxicity, andexcellent water solubility. The integration of CDs into AgI significantly enhances charge transfer and suppresses electron–hole recombination. The resulting AgI–CD composites exhibited superior photocatalytic activity (97% in 150 min) for the degradation of the pesticide Thiram, with the composite containing 10 wt% CD achieving the highest performance. This study not only provides a green recycling route for waste paper but also demonstrates the potential of AgI–CD composites for effective environmental remediation