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From Silk Biomass to Surface-Active Lipopeptides: Mechanochemical Synthesis and Characterization
No full textInternational audienceSilk is defined as non-food biomass produced by cultured silkworms and it's composed of two types of proteins, fibrous protein called fibroin and a glue-like protein called sericin [1]. Global silk cocoon production is approximately 800,000 tons per year. Traditionally, the main application of silk is the textile industry due to the luster and mechanical properties of fibroin fibers. However, sericin is actually not valorized industrially and release in the environment more than 50,000 tons per year. In this work, we aim to develop new ways for valorizing silk proteins for high value-added applications. Nowadays, bio-based surfactants derived from agricultural biomass have become highly sought after to comply with new regulations that promote natural-based products [2]. In this context, the main objective of the present work is the development of alternative technologies to produce lipopeptide surfactants from silk as nonfood biomass.The first step of silk lipopeptide production involves the separation of silk protein fractions, sericin and fibroin. These proteins were subsequently modified through enzymatic hydrolysis and an acylation reaction. The originality of this study is the development of a mechanochemical approach [3] as an alternative to the conventional lipopeptide synthesis method [4]. Two acylation methods were investigated: pre-activation of fatty acid by 1,1carbonyldiimidazole and amidation of a fatty ester. The obtained results show that the two silk protein fractions can be efficiently separated. Silk sericin and fibroin fractions were hydrolyzed using Alcalase® enzyme with a degree of hydrolysis varying between 20 and 50%. Moreover, the results of functionalization of silk peptides by mechanochemistry show very promising results with acylation rates varying from 50 to 80%. Silk lipopeptides with different fatty chains demonstrated good surface activity with emulsifying and foaming capacities comparable to, or even better than those of commercial surfactants such as SDS and Tween 20. The lipopeptides synthesized under solventless conditions show strong potential to replace petroleum-based surfactants in various formulations, particularly in cosmetics and household detergents.</p
An original approach for multiscale modeling of the skeletal muscle
No full textInternational audienceFinite element (FE) models are increasingly used to analyze the effect of components at different scales on the overall mechanical response of the skeletal muscle [1]. The most critical points lie in modeling the transition from one anatomical scale to the others. We propose to use periodic Representative Volume Elements (RVE) to integrate parameters related to muscle fiber type distribution, geometric and mechanical characteristics. We developed an original approach based on 3D periodic RVE generation for the multiscale FE modeling of the skeletal muscle. By including custom geometrical features (such as component distributions) and material properties (including a smooth transition layer), this model could be used for multiscale, multi-component analysis of different muscle phenotypes
Modeling Access Ergonomics to Daily Life Resources Using Sustainable Modes within the Eurométropole de Strasbourg
No full textInternational audienceSince the 1980s, many cities in Europe, including the Eurométropole de Strasbourg, have implemented policies to reduce transportation and mobility related negative impacts, especially those caused by individual cars. In the Eurométropole de Strasbourg, measures have been introduced to limit car use while promoting sustainable transport. This includes developing public transportation, enhancing shared and active modes (walking, cycling) usage, and urban planning focused on a “proximity metropolis” model to support sustainable mobility.Furthermore, the Eurométropole de Strasbourg has restricted motorized mobility, particularly internal combustion engine vehicles, by creating a Low Emission Zone covering its 33 municipalities. The city also supports energy transition, encouraging the adoption of electric vehicles including electric bikes through purchase subsidies. The central question is how well the Eurométropole de Strasbourg enables its residents to access essential daily-life resources, efficiently, comfortably, and at low cost (financial cost, effort, risk, emissions, energy and time) while using sustainable transport modes.To address this, spatial ergonomics (Saint-Gérand, 2002) which studies the capacity for a territory to fulfil the needs of its inhabitants at least costs, and especially its subdomain access ergonomics (Hached, 2019) which provides an approach through mobility, offer a relevant analytical framework. This approach assesses accessibility while focusing on its conditions not only regarding travel duration but also considering daily-life resources and infrastructure quality (facilities, safety, comfort, environment) adapted to each transport mode.The hypothesis is that a high-quality environment helps to promotes sustainable transport, especially for active modes. Mobility behaviors, including route choices, are influenced by safety, comfort, and environmental factors (Piombini, 2013). Access ergonomics integrates these factors into a synthetic access ergonomics score composed of several sub-indicators to identify socio-spatial inequalities in accessing daily resources.Previous studies (Saint-Gérand et al., 2021) showed significant variability in access across the Eurométropole de Strasbourg; however, they did not consider emerging mobility forms, such as electric vehicles and micromobility. The rise of micromobility and intermodality requires adaptation of these analyses.Activity-based models are used for evaluating accessibility through a trip completion rate by measuring the proportion of the trips below a certain threshold (Somranath et al., 2025). This approach however does not consider key parts of access ergonomics (safety and convenience of trips).Our study aims to improve realism and precision in evaluating access ergonomics. A new methodology has been developed to overcome limitations from previous works. Multi-agent modeling is used to simulate mobility behaviors based on detailed socio-spatial profiles, considering diverse socio-economic and demographic data at a fine scale (200 × 200 m). These profiles are fed to a geographic information system to assess access conditions using various transport modes (active, shared, motorized, intermodal).Trips are analyzed within activity chains, where each activity (work, leisure, services) can be interconnected. The model also considers resource availability and transport service schedules, identifying potential inconsistencies that impact access ergonomics.The study relies on open geographic and statistical data covering the Eurométropole de Strasbourg. The synthetic population is generated using eqasim (Hörl and Balac, 2021), and user profiles are adjusted based on socio-demographic data and mobility surveys.The goal is also to develop a tool which will generate an access ergonomics score for each inhabited grid square, providing a detailed and comprehensive view of socio-spatial inequalities. The synthetic score will be broken down into sub-indicators (travel time, safety, comfort, etc.) and transport modes, enabling comparison across the territory.These results will help to identify actions for improving access ergonomics and for reducing inequalities. In further studies, the developed tool will be improved by considering the aspect of energy transition, especially to take its consequences into account on the access ergonomics
Modelling of Nanocrystalline Common-Mode Chokes with Custom Shape by Simulation-Based Extraction of Effective Permeability
No full textInternational audienceKnowing the complex relative permeability of a ferrite or nanocrystalline core material is crucial to predict the insertion impedance of common-mode chokes. In practice, however, the material properties are often not known across the full desired frequency range. Additionally, factors like core shape, lamination and strip thickness influence the effective permeability and consequently the choke's impedance behaviour. This paper presents a workflow to create core material models that can be used in electromagnetic simulations to estimate the impedance behaviour of common-mode chokes. The core's material characteristics are determined by iteratively fitting model parameters to an impedance measurement using a generic laboratory setup. The resulting core model is then employed to predict the impedance of a common-mode choke in the intended application
Predictive maintenance and control tool for hydrogen-energy systems in an industrial framework
No full textInternational audienceIn this paper, the structure and different axes for the realization of an efficient predictive tool have been defined, to improve durability, availability, reliability, performance, safety and operating costs of hydrogen-energy systems. The predictive tool based on predictive maintenance and predictive control is intended to be marketed economically
Influence of Controller Parameters on Open-Circuit Fault Localization Time in Full-Bridge Modular Multilevel Converter
No full textInternational audienceModular Multilevel Converters (MMCs) have gained significant attention in academia and industry due to their versatility in various applications. MMCs are known for their high efficiency, superior harmonic performance, scalability, and modularity. However, their complexity in control, reliability issues, and many components present challenges. Numerous submodule (SM) configurations have been proposed in the literature, each with advantages and disadvantages. The full-bridge (FB) configuration stands out for its robustness against DC link faults. Nevertheless, the FB SM containing four switches is susceptible to open-circuit failures (OCF). Few studies have explored such failures in FB MMCs. This paper investigates the impact of controller parameters on fault localization time in the event of an OCF in any of the four switches. The study uses two different modulation strategies, and the results are validated through simulation
Current Sensor-free Transfer Window Alignment for Current Transformer Energy Harvesting
No full textThis paper was presented at the EPE 2025 conference and was subsequently selected for publication in the special issue of Elsevier's PEDC journal. Therefore, only the abstract appears on the conference website.International audienceAn energy harvesting circuit has been developed to power an IoT network which measures energy consumption at the outlet level. This work integrates the rectification and down-stream voltage regulation stages, allowing the capacitor voltage to be used to measure current. An experimental prototype is developed to demonstrate the proposed algorithm
Design Optimization of Integrated CM/DM Inductors for Power Drive Input Filter
No full textThis paper was presented at the EPE 2025 conference and was subsequently selected for publication in the special issue of Elsevier's PEDC journal. Therefore, only the abstract appears on the conference website.International audienceMore electric aircraft face many challenges regarding weight and losses of power quality and EMI filters. A solution to reduce weight and losses is integrating the Differential Mode (DM) and Common Mode (CM) inductances of filters in the same component. This integration can be accomplished by adding extra magnetic paths and windings to a CM choke to increase its leakage inductance further. This paper proposes a design optimization of an integrated CM/DM inductor for EMI input filters of Power Drive Systems used in more electric aircraft. The integrated solution is then compared to an optimized discrete solution, showing significant reductions in weight and losses
Amélioration de l'expérience utilisateur du secteur automobile grâce à l'orchestration dynamique des services embarqués pour les véhicules définis par logiciel
No full textPreprint for submission at IEEE Transactions on Intelligent Transportation Systems.International audienceWith the increasing demand for dynamic behaviors in automotive use cases, Software Defined Vehicles (SDVs) have emerged as a promising solution by bringing dynamic onboard service management capabilities. While users may request a wide range of services during vehicle operation, background tasks such as cooperative Vehicle-to-Everything (V2X) services can activate on-the-fly in response to real-time road conditions. In this dynamic environment, the efficient allocation of onboard resources becomes a complex challenge, in order to meet mixed-criticality onboard Quality-of-Service (QoS) network requirements while ensuring an optimal user experience. Additionally, the ever-evolving real-time network connectivity and computational availability conditions further complicate the process. In this context, we present a dynamic resource-based onboard service orchestration algorithm that considers real-time in-vehicle and V2X network health, along with onboard resource constraints, to select degraded modes for onboard applications and maximize user experience. To enable dynamic orchestration, we introduce the concept of Automotive eXperience Integrity Level (AXIL) which expresses a runtime priority for non-safety-critical applications. This algorithm produces near-optimal solutions while significantly reducing execution time compared to straightforward methods as demonstrated by simulation results. With this approach, we aim to enable efficient onboard execution for a user experience-focused service orchestration
From Space to Industrial Applications: the Latching Current Limiter as Active Current Protection
No full textInternational audienceThis paper presents the Industrial Latching Current Limiter, a converter topology for fast fault detection and management and inrush current limiting in industrial power systems. By integrating a bypass transistor and switching elements in a synchronous buck converter configuration, it enhances efficiency supporting continuous operation under overload conditions