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Improvement of Sinapine Extraction from Mustard Seed Meal by Application of Emerging Technologies
No full textInternational audienceSinapine is a phenolic compound found in mustard (Brassica juncea) seed meal. It has numerous beneficial properties such as antitumor, neuroprotective, antioxidant, and hepatoprotective effects, making its extraction relevant. In this study, the extraction of sinapine was investigated using three methods: (i) from a mustard seed meal defatted by a supercritical CO 2 (SC-CO 2) pretreatment, (ii) by the implementation of high-voltage electrical discharges (HVEDs), (iii) and by the use of ultrasound. The use of SC-CO 2 pretreatment resulted in a dual effect on the valorization of mustard seed meal, acting as a green solvent for oil recovery and increasing the yield of extracted sinapine by 24.4% compared to the control. The combination of ultrasound and SC-CO 2 pretreatment further increased the yield of sinapine by 32%. The optimal conditions for ultrasound-assisted extraction, determined through a response surface methodology, are a temperature of 75 • C, 70% ethanol, and 100% ultrasound amplitude, resulting in a sinapine yield of 6.90 ± 0.03 mg/g dry matter. In contrast, the application of HVEDs in the extraction process was not optimized, as it led to the degradation of sinapine even at low-energy inputs
Coupling electrical parameters of a battery equivalent circuit model to electrodes dimensions
No full textInternational audienceThe design of a battery-powered system ideally requires the simultaneous sizing of all its components. To contribute to this purpose, we propose a physical approach to couple the electrical parameters of a battery equivalent-circuit-model (ECM) to the electrodes dimensions of the battery. Because it only requires non-invasive measurements, it can be easily used by system integrators. To test the proposed approach, we choose three commercial coin cells with different sizes and nominal capacities (25 mAh, 60 mAh and 120 mAh). Only the electrodes length of these cells varies, and this study is therefore focused on creating dependency-models that predict the ECM parameters values with respect to this specific dimension. The proposed ECM brings accurate voltage simulations and the dependency-models predictions are satisfactory for the three cells, with a mean accuracy of 6.3%. Thanks to the proposed approach, the parameters of any cell size and capacity can be predicted in the characterization range (between 25 mAh and 120 mAh here). It is thus a promising tool for developing custom-made cells
Towards Ready-to-Use Iron-Crosslinked Alginate Beads as Mesenchymal Stem Cell Carriers
No full textInternational audienceMicro-carriers, thanks to high surface/volume ratio, are widely studied as mesenchymal stem cell (MSCs) in vitro substrate for proliferation at clinical rate. In particular, Ca-alginate-based biomaterials (sodium alginate crosslinked with CaCl2) are commonly investigated. However, Ca-alginate shows low bioactivity and requires functionalization, increasing labor work and costs. In contrast, films of sodium alginate crosslinked with iron chloride (Fe-alginate) have shown good bioactivity with fibroblasts, but MSCs studies are lacking. We propose a first proof-of-concept study of Fe-alginate beads supporting MSCs proliferation without functionalization. Macro- and micro-carriers were prepared (extrusion and electrospray) and we report for the first time Fe-alginate electrospraying optimization. FTIR spectra, stability with various mannuronic acids/guluronic acids (M/G) ratios and size distribution were analyzed before performing cell culture. After confirming literature results on films with human MSCs, we showed that Macro-Fe-alginate beads offered a better environment for MSCs adhesion than Ca-alginate. We concluded that Fe-alginate beads showed great potential as ready-to-use carriers
Excellent Balance of Ultimate Tensile Strength and Ductility in a Ti–6Al–2Sn–4Zr–2Mo–Si Alloy Having Duplex α + α′ Microstructure: Effect of Microstructural Factors from Experimental Study and Machine Learning
No full textInternational audienceThis research focuses on the systematic study of a Ti–6Al–2Sn–4Zr–2Mo–Si titanium alloy and the characterization of α + β (equiaxed and bimodal) and α + α′ (duplex) microstructures. It provides more insights on the outstanding advantages of the duplex (α + α′) microstructure, especially on its exceptional work hardening and strength-ductility balance. The heat treatment conditions required to form equiaxed, bimodal and duplex microstructures and their effects on the grain size and the phase proportion are discussed. It shows how the microstructural parameters can be controlled thanks to the heat treatment temperatures, the holding times and possible aging processes. The influence of such microstructural factors on the tensile properties of each alloy is investigated, especially on strength (proof stress, ultimate tensile strength), ductility (plastic elongation) and work hardening properties. The duplex (α + α′) microstructure is compared with the equiaxed and bimodal microstructures and its advantages are displayed, highlighting the better strength-ductility balance and superior work hardening properties of the duplex microstructure. Indeed, the deformed microstructure of the duplex (α + α′) microstructure reveals more homogeneous strain partitioning than that of the bimodal (α + β) microstructure. Thus, this work proved the potential of an optimized duplex (α + α′) microstructure for the enhanced tensile properties at room temperature. Finally, a machine learning model using gradient boosting regression trees is used to quantify the importance of the microstructural factors (type of microstructure, grain size and phase ratio) on the mechanical properties
Overview of Numerical Simulation of Solid-State Anaerobic Digestion Considering Hydrodynamic Behaviors, Phenomena of Transfer, Biochemical Kinetics and Statistical Approaches
No full textInternational audienceAnaerobic digestion (AD) is a promising way to produce renewable energy. The solid-state anaerobic digestion (SSAD) with a dry matter content more than 15% in the reactors is seeing its increasing potential in biogas plant deployment. The relevant processes involve multiple of evolving chemical and physical phenomena that are not crucial to conventional liquid-state anaerobic digestion processes (LSAD). A good simulation of SSAD is of great importance to better control and operate the reactors. The modeling of SSAD reactors could be realized either by theoretical or statistical approaches. Both have been studied to a certain extent but are still not sound. This paper introduces the existing mathematical tools for SSAD simulation using theoretical, empirical and advanced statistical approaches and gives a critical review on each type of model. The issues of parameter identifiability, preference of modeling approaches, multiscale simulations, sensibility analysis, particularity of SSAD operations and global lack of knowledge in SSAD media evolution were discussed. The authors call for a stronger collaboration of multidisciplinary research in order to further developing the numeric simulation tools for SSAD
Extracting the diffusion resistance and dynamic of a battery using pulse tests
No full textInternational audienceThe modeling of a battery by an equivalent circuit model requires the determination of its parameters. This determination can be done by exploiting the transient response of a battery to a current pulse (often called GITT: galvanostatic intermittent titration technique). A classical approach is to first separate the open circuit voltage (OCV) and the overvoltage, and then to extract the model parameters from the latter. However, the estimation of the OCV can be difficult, which can lead to errors on the overvoltage, especially for slow dynamics such as diffusion. We propose here a method to estimate the OCV during GITT and a method to estimate the overvoltage which allow the extraction of parameters associated with slow dynamics. The results brought by the proposed method are compared with more classical approaches
Teachers Facing Psychosocial Risks: Adaptation of a French Context Questionnaire to Egypt
No full textInternational audienceThe internationalization of university studies has led to reforms which may have produced significant changes in the working conditions of teachers. This situation can lead to the development of factors promoting the emergence of psychosocial risks (PSRs) that can have significant implications on the health of these teachers. One of the well-known PSRs is the stress that teachers may experience due to heavy workloads, lack of social support and limited resources. This can lead to frustration, lack of motivation and/or burnout, which can affect the quality of teaching and student outcomes. Although many studies exist in France to identify the PSRs in order to prevent them, it is yet limited in Egypt. This work is in line with the objectives of the Imhotep project in order to prevent teachers from psychosocial risks at work. The aim of this study is to present the process of adapting and validating a French questionnaire for assessing psychosocial risks in the Egyptian context
Planification de ressources et ordonnancement de tâches dans la chaîne inter et intra logistique hospitalière
No full textHospitals must take into account logistics to improve the connections between healthcare systems (between facilities and within hospital divisions) in order to promote consistency and efficiency. Hospital logistics involves effectiv coordination of patient care services. Patients in emergency situations typically first go to the emergency department. A visit to the emergency department may reveal that a patient needs a surgical intervention to be scheduled later. This creates elective surgery patients. As part of the ANR OIILH project, we proposed solutions to the patient care pathway scheduling problem. We also studied the problem of scheduling surgical interventions. For the emergency department problem, we first considered the static case. We developed an instance generator based on real data from the emergency department at CHU Jeanne de Flandres in Lille. We implemented a constructive heuristic approach to manage resources following two business rule used by practitioners. We proposed a mathematical modeling of the problem. The model was implemented and used to obtain reference solutions for generated instances. We developed an iterative heuristic approach based on the destruction and construction of a solution. The results show that solutions of higher quality compared to the constructiv heuristic can be obtained in reasonable time frames. Optimal solutions can be found for small instances. Then, we developed a more efficient Adaptive Large Neighborhood Search (ALNS) metaheuristic. Experimental results demonstrat the effectiveness of this approach With Iow computing times suitable for the required responsiveness in dynamic proble cases. We proposed a predictive and reactive planning approach for the dynamic case. We build, modify, and improve the plan using static case resolution methods. For the surgery service, non-urgent and non-immediate surgical interventions need to be scheduled in advance. We developed two resolution approaches for this problem downstream from the emergency department. We proposed a two-phase heuristic and an ALNS approach that produce results strictly better than those in the literature.Les hôpitaux doivent prendre en compte la logistique pour améliorer les liens entre les systèmes de santé (entre les établissements et entre les divisions au sein d’un hôpital) afin de promouvoir la cohérence et l’efficacité. La logistique hospitalière implique une bonne coordination des services de prise en charge des patients. Les patients en situation d’urgence se rendent généralement en premier lieu au service des urgences. Une visite aux urgences peut révéler qu’un patient a besoin d’une intervention chirurgicale à programmer plus tard. Cela crée des patients en chirurgie élective. Dans le cadre de l’ANR OIILH, nous avons proposé des solutions pour le problème d’ordonnancement des tâches de parcours de soins de patients. Nous avons également étudié le problème de planification d’interventions chirurgicales. Pour le problème des urgences, nous avons considéré en premier lieu le cas statique. Nous avons réalisé un générateur d’instances basé sur les données réelles du service d’urgence du CHU Jeanne de Flandres de Lille. Nous avons implémenté une approche heuristique constructive permettant de gérer les ressources en suivant deux règles métier utilisées par les praticiens. Nous avons proposé une modélisation mathématique du problème. Le modèle a été implémenté et utilisé pour obtenir des solutions de références pour les instances générées. Nous avons élaboré une approche heuristique itérative basée sur la destruction et la construction d’une solution. Les résultats montrent que des solutions de meilleure qualité par rapport à l’heuristique constructive peuvent être obtenues en des temps raisonnables. Des solutions optimales peuvent être trouvées pour les petites instances. Ensuite, nous avons élaboré une méta-heuristique « Adaptive Large Neighborhood Search (ALNS) » plus efficace. Les résultats expérimentaux montrent l’efficacité de cette approche avec des temps de calcul faibles qui sont adéquats par rapport à la réactivité requise dans le cas dynamique du problème. Nous avons proposé une approche de planification prédictive et réactive pour le cas dynamique. Nous construisons, modifions et améliorons le planning en utilisant les méthodes de résolution du cas statique. Pour le service de chirurgie, des interventions chirurgicales non urgentes et non immédiates doivent être programmées à l’avance. Nous avons développé deux approches de résolution pour ce problème en aval du service des urgences. Nous avons proposé une heuristique en deux phases et une approche ALNS qui donnent des résultats strictement meilleurs que ceux de la littérature
Proofs of Network Quantum Nonlocality in Continuous Families of Distributions
No full textInternational audienc
Iodixanol as a New Contrast Agent for Cyanoacrylate Embolization: A Preliminary In Vivo Swine Study
No full textInternational audienceN-butyl cyanoacrylate (NBCA) is a lipophilic, permanent embolic glue that must be opacified for fluoroscopic guidance. Empirically, lipophilic Lipiodol Ultra Fluid ® (LUF) has been added to produce a single-phase physically stable mixture. Varying the dilution ratio allows control of glue polymerization kinetics. LUF is far more costly than water-soluble iodinated contrast agents (ICAs). Our purpose was to evaluate whether a water-soluble nonionic iso-osmolar ICA could be used instead. We embolized both renal arteries of six swine using 1:3 NBCA-LUF or NBCA-iodixanol in 1:1, 1:3, and 1:7 ratios. We used both micro-computed tomography to assess the distality of glue penetration and indexed cast ratio and histology to assess distality, arterial obliteration, vesselwall damage, and renal-parenchyma necrosis. Glue-LUF produced significantly greater indexed cast ratio and renal-artery ROI values and a significantly shorter cast-to-capsule distance. The injected volume was significantly greater with 1:7 iodixanol than with the other mixtures. No significant differences were found for histological evidence of artery obliteration, vessel-wall damage, or renal-parenchyma necrosis. This is the first study dealing with ICA alone as a contrast agent for cyanoacrylate embolization, compared to LUF. More research is needed to determine whether water-soluble nonionic iodinated agents can be used for human NBCA embolization given the good safety profile, availability, and low cost of ICA.</div