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Towards a Personalized Business Services Recommendation System Dedicated to Preventing Frailty in Elderly People
No full textInternational audienceAbstract Frailty is a clinical syndrome associated with ageing that characterizes an intermediate state between robust health and loss of autonomy. To preserve the abilities of older adults and prevent dependency, it is important to identify and evaluate their frailty. This approach is part of a dependency prevention strategy, based on a thorough understanding of their medical, social, and living environment. This understanding is usually acquired through significant data collection using standardized evaluation surveys. The obtained data is then analyzed to provide personalized recommendations for the beneficiaries’ lifestyles. Our article presents the concept of frailty and a personalized recommendation system aimed at helping citizens prevent frailty. This system uses an innovative self-assessment approach designed for older adults, without necessarily involving healthcare professionals
Composite laminates reinforced by vertically aligned carbon nanotubes: Detailed manufacturing process, from nanotubes transfer to composite consolidation
No full textInternational audienceNano-constituent incorporation into composites has been extensively studied in the literature due to its improvement in static and dynamic mechanical properties, as well as its prevention from interlaminar crack initiation and propagation. This work introduces a detailed manufacturing process of nano-engineered composite laminates, from impregnation to consolidation, without damaging the initial morphology of carbon nanotubes transferred on prepreg interfaces. Based on prepreg and vertically aligned carbon nanotubes (VACNTs) synthesized on an aluminium alloy (Al) substrate, the impregnation step allows for the transfer of VACNTs onto the prepreg surface through partial resin-rising capillarity. The Al alloy substrate is then removed from the VACNTs through a separation step, ensuring highly effective and repeatable transfer with more than 80% VACNTs transferred onto the prepreg surface. This paper provides insight into the impregnation and transfer processes and guides the choice of process parameters to ensure minimal VACNTs buckling during the consolidation of the hybrid composites at high pressure in an autoclave
Extensive investigation of geometric effects in sonoreactors: Analysis by luminol mapping and comparison with numerical predictions.
No full textInternational audienceThis investigation focuses on the influence of geometric factors on cavitational activity within a 20kHz sonoreactor containing water. Three vessels with different shapes were used, and the transducer immersion depth and liquid height were varied, resulting in a total of 126 experiments conducted under constant driving current. For each one, the dissipated power was quantified using calorimetry, while luminol mapping was employed to identify the shape and location of cavitation zones. The raw images of blueish light emission were transformed into false colors and corrected to compensate for refraction by the water–glass and glass-air interfaces. Additionally, all configurations were simulated using a sonoreactor model that incorporates a nonlinear propagation of acoustic waves in cavitating liquids. A systematic visual comparison between luminol maps and color-plots displaying the computed bubble collapse temperature in bubbly regions was conducted. The calorimetric power exhibited a nearly constant yield of approximately 70% across all experiments, thus validating the transducer command strategy. However, the numerical predictions consistently overestimated the electrical and calorimetric powers by a factor of roughly 2, indicating an overestimation of dissipation in the cavitating liquid model. Geometric variations revealed non-monotonic relationships between transducer immersion depth and dissipated power, emphasizing the importance of geometric effects in sonoreactor. Complex features were revealed by luminol maps, exhibiting appearance, disappearance, and merging of different luminol zones. In certain parametric regions, the luminol bright regions are reminiscent of linear eigenmodes of the water/vessel system. In the complementary parametric space, these structures either combine with, or are obliterated by typical elongated axial structures. The latter were found to coincide with an increased calorimetric power, and are conjectured to result from a strong cavitation field beneath the transducer producing acoustic streaming. Similar methods were applied to an additional set of 57 experiments conducted under constant geometry but with varying current, and suggested that the transition to elongated structures occurs above some amplitude threshold. While the model partially reproduced some experimental observations, further refinement is required to accurately account for the intricate acoustic phenomena involved
Solid amorphous formulations for enhancing solubility and inhibiting Erlotinib crystallization during gastric-to-intestinal transfer
No full textInternational audienceThe objective of this study was to improve the solubility and inhibit the crystallisation during the gastric-to-intestinal transfer of Erlotinib (ERL), a small molecule kinase inhibitor (smKI) compound class, which is classified as class II drug in the Biopharmaceutical Classification System (BCS). A screening approach combining different parameters (solubility in aqueous media, inhibitory effect of drug crystallisation from supersaturated drug solutions) was applied to selected polymers for the development of solid amorphous dispersions of ERL. ERL solid amorphous dispersions formulations were then prepared with 3 different polymers (Soluplus®, HPMC-AS-L, HPMC-AS-H) at a fixed drug: polymer ratio (1:4) by two different production methods (spray drying and hot melt extrusion). The spray-dried particles and cryo-milled extrudates were characterized by thermal properties, shape and particle size, solubility and dissolution behavior in aqueous media. The influence of the manufacturing process on these solid characteristics was also identified during this study. Based on the obtained results, it is concluded that the cryo-milled extrudates of HPMC-AS-L displayed better performance (enhanced solubility, reduced ERL crystallization during the simulated gastric-to-intestinal transfer) and represents a promising amorphous solid dispersion formulation for oral administration of ERL
Implémentation d'une interopérabilité fédérée supportée par la transformation automatisée à la volée de modèles de données hétérogènes : application aux problèmes d'appariement des schémas
No full textToday, the industrial world is experiencing advances in information and communication technologies under the umbrella of Industry 4.0 and 5.0. Organisations are continuously looking for adaptability and flexibility in a competitive and dynamic context. These technologies are often called upon by these organisations to improve their performance and their ability to achieve their objectives. The adoption of these technologies is not uniform and leads to an increase in the amount of heterogeneous data. Interoperability is therefore crucial, as it enables the exchange and use of this data. Interoperability is an essential mechanism when it comes to software upgrades, technical migrations or connector implementations to ensure communication with third party services, software or companies. The work carried out within the framework of this thesis focuses on the implementation of a generic and adaptable approach based on the principles of federated interoperability between databases. The federated approach does not impose any data model or format. Interoperability is implemented on-the-fly and is most likely to meet the requirements of adaptability and flexibility in dynamic environments. The thesis presents and analyses the current state of the art on the notion of interoperability. The transposition of this analysis has allowed to propose a general framework that gathers the literature and describes the different concepts of interoperability. This framework has motivated the development of a federated approach that aims to exploit the available information to the maximum. To this end, the thesis draws on techniques from natural language processing, optimisation and graph theory. The approach has been applied to two case studies of schema matching problems.Aujourd'hui, le monde industriel connaît des avancées des technologies de l'information et de la communication sous l'ombrelle de l'industrie 4.0 et 5.0. Les organisations sont à la recherche continue d'adaptabilité et de flexibilité dans un contexte compétitif et dynamique. Ces technologies sont souvent sollicitées par ces organisations pour améliorer leurs performances et leurs capacités à atteindre leurs objectifs. L'adoption de ces technologies n'est pas uniforme et entraîne une augmentation de la quantité de données hétérogènes. L'interopérabilité est alors cruciale, car elle permet l'échange et l'utilisation de ces données. Les travaux menés dans le cadre de cette thèse s'intéressent à la mise en œuvre d'une approche générique et adaptable sur les principes d'une interopérabilité fédérée entre des bases de données. L'approche fédérée n'impose aucun modèle ou format de données. L'interopérabilité est mise en œuvre à la volée et est la plus à même à répondre aux exigences d'adaptabilité, de flexibilité dans des environnements dynamiques. La thèse présente et analyse l'état de l'art actuel sur la notion de l'interopérabilité. La transposition de cette analyse a permis de proposer un cadre général qui rassemble la littérature et décrit les différents concepts de l'interopérabilité. Ce cadre a motivé le développement d'une approche fédérée qui vise à exploiter au maximum les informations disponibles. Pour cela, la thèse s'inspire des techniques issues du traitement automatique des langues, l'optimisation et la théorie des graphes. L'approche a été appliquée sur deux cas d'étude pour des problèmes d'appariement des schémas
Vers une estimation de la demande adaptée aux systèmes de transports hyperconnectés en milieu régional
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Challenges and Concept for an Interoperable Digital Twin Architecture for PV-Integrated Heating Networks
No full textInternational audienceExisting data-driven approaches are not always supported, or only partly implemented, by existing tools, platforms, and services. The study focuses on proposing a novel, theoretical and general model to describe the heating network of buildings. This study will consolidate and abstract access to standardized interfaces, using a transparent interoperability mechanism, the “meta” interface, supporting translation modules to translate from different components or hardware that are commonly used in current heating networks of buildings in Europe. The ICT architecture will be based on state-of-the-art digital twin technologies and methodologies, offering a unified ecosystem for orchestrated deployment of different input/output configurations, and data flow and energy exchanges. This study will further validate the reference ICT architecture using data-driven approaches, applied in a use case that could be considered a typical low-temperature district heating network
Sintering of particles: grain-growth and non-sphericity treated with DEM
No full textInternational audienceSintering of ceramic powders is a high-temperature process that aims to densify an initially particulate material. The driving force is the reduction of the interfacial energy of the system. The same driving force leads to grain growth, which is generally considered detrimental. Here we explore the coupling between densification and grain growth at the particle scale. Simultaneously occurring shrinkage, surface diffusion, grain migration and particle coalescence are implemented in a DEM framework. The adopted model treats the main fluxes of matter through physics-based interaction laws. Small particles are gradually eaten away by larger ones, leading to coalescence and grain growth. The results of these simulations are compared to experimental data with good accordance of key features of microstructure evolution (densification kinetics, grain size-density trajectory, average grain size evolution). By taking advantage of the possibility to simulate initially a large number of particles (which gradually disappear with coalescence), the model elucidates the influence of the initial particle size distribution on the grain growth kinetics. Because ceramic particles are seldom spherical, we also implemented non-spherical particles using the Level-Set method. This is particularly important for sintering, as it is a curvature driven process. Contact detection, which is the critical step, is treated as an optimization problem, to reduce computational costs. The proposed implementation of LS-DEM is a proof of concept of its potential effectiveness for sintering. For illustration, simulations of packings of ellipsoidal particles with elastic and sintering interactions are described. The sintering simulations are used to analyze the influence of the particle aspect ratio, in particular on the shrinkage rate
Élaboration de mousses biopolymères par procédés assistés par CO2 supercritique (thèse sous embargo)
No full textPolylactic acid (PLA) is a commercially available biopolymer that is of great interest in various industrial fields, especially for the production of polymer foams. With the development of technologies that seek to reduce the environmental impact of processes, chemical foaming agents are being replaced by physical agents, mainly supercritical fluids (SCF) such as carbon dioxide (sc-CO2). Currently, the mass production of low-density PLA foams with uniform microcellular morphology using SCFs as foaming agents is a challenge. This is mainly due to the low melt strength of PLA and its slow crystallisation kinetics. Among the different options to improve the characteristics of PLA, combining it with different types of fillers has great potential to improve the foaming but also the performance of the final composites. Moreover, the operating conditions and the characteristics of the fillers such as their size, aspect ratio, and surface chemistry play an important role in the final foam morphology. In this context, this work focused on the fabrication of composite foams from PLA and cellulose fibres usingsupercritical CO2 (sc-CO2) as foaming agent. The first part of the work was devoted to the formulation of the composites and the study of their properties, in particular the effect of the fibres on crystallinity. These composites were then foamed by a batch process and a continuous sc-CO2 assisted extrusion process. The effect of cellulose content and aspect ratio (length/diameter) on the solidification and crystallisation kinetics of PLA was studied. These results are used as a means of understanding the morphology and characteristics of the PLA-cellulose composite foams produced.L'acide polylactique (PLA) est un biopolymère disponible dans le commerce qui suscite un grand intérêt dans divers domaines industriels, notamment pour la production de mousses polymères. Avec l'essor des technologies qui cherchent à réduire l'impact environnemental des procédés, les agents moussants chimiques sont remplacés par des agents physiques, principalement des fluides supercritiques (FSC) comme le dioxyde carbone (sc-CO2). Actuellement, la production de masse de mousses PLA à faible densité avec une morphologie microcellulaire uniforme en utilisant des FSC comme agents moussant est un défi. Ceci est principalement dû à la faible résistance à l'état fondu du PLA et à sa cinétique de cristallisation lente. Parmi les différentes options pour améliorer les caractéristiques du PLA, le combiner avec différents types de charges a un grand potentiel pour améliorer le moussage mais également les performances des composites finaux. De plus, les conditions opératoires et les caractéristiques des charges telles que leur taille, leur rapport d'aspect et leur chimie de surface jouent un rôle important dans la morphologie finale de la mousse. Dans ce contexte, ce travail s'est intéressé à la fabrication de mousses composites à partir de PLA et de fibres de cellulose en utilisant le CO2 supercritique (sc-CO2) comme agent moussant. Une première partie du travail a été consacrée à la formulation des composites et à l'étude de leurs propriétés, notamment l'effet des fibres sur la cristallinité. Ces composites ont ensuite été moussés par un procédé discontinu et un procédé continu d'extrusion assistée par sc-CO2. L'effet de la teneur en cellulose et du rapport d'aspect (longueur/diamètre) sur la cinétique de solidification et de cristallisation du PLA a été étudié. Ces résultats sont utilisés comme un moyen de comprendre la morphologie et les caractéristiques des mousses composites de PLA-cellulose produites