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Une affaire de lignages ? Chambellanies et chambellans des ducs capétiens de Bourgogne (XIIe-XIVe siècle)
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« La Cinquième République à l’épreuve du “fait minoritaire” », corrigé du sujet de dissertation donné à l’Université Le Havre Normandie au second semestre 2024-2025
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Development of a Microwave‐Driven Large‐Area and Uniform Plasma Device With Dual‐Frequency
No full textInternational audienceABSTRACT In this paper, a dual‐frequency (915 MHz and 2450 MHz) microwave low‐pressure plasma source based on a rectangular cavity and feeding waveguides equipped with slot‐array antennas was designed. A large‐area, uniform plasma was obtained. Experiments showed that plasma discharge was much more uniform under dual‐frequency compared to single‐frequency. Plasma volume uniformity of argon plasma under dual‐frequency could achieve up to 80.2% when incident power was 800 W and pressure was 100 Pa, while its line uniformity achieved 99.6%. Dependence of incident power, power ratio of dual‐frequency, and various working gases with plasma uniformity were investigated. Adjusting sliding shorts, energy coupling efficiency of the cavity was effectively enhanced. Overall, the dual‐frequency plasma device offered a novel approach to improve plasma uniformity
Wearable Smart Gloves Based on Laser-induced Graphene for Multimodal Sensing and AI-Enhanced Recognition
No full textInternational audienceThis study presents a comprehensive investigation of laser-induced graphene (LIG) for multimodal sensing applications. LIG, synthesized through direct laser irradiation of polyimide substrates, offers unique advantages such as high throughput, programmable patterning, and environmental friendliness. We explore the effects of laser intensity and scanning speed on the microstructure and sensing performance of LIG. Various LIG patterns are designed and tested for bending, tactile, temperature, humidity, and sweat sensing experiments. The results demonstrate that LIG-based sensors exhibit high sensitivity, linearity, and repeatability. Specifically, the R2-LIG sensor shows optimal performance for bending sensing with 873.1% resistance change at 30 N and 97.5% accuracy for 8 materials via a CNN deep learning model, enabled by a four-stage signal preprocessing, e.g., data augmentation, resolution unification, ImageNet channel standardization and dynamic dimension calculation. Furthermore, by coating LIG with PEDOT: PSS, we enhance its temperature sensing properties, enabling temperature-sensitive sensing applications. Based on these findings, we developed a smart glove incorporating these LIG sensors, which can monitor hand joint movements, recognize tactile inputs, and sense temperature changes in real time. This study highlights the versatile sensing potential of LIG and its promising applications in wearable devices and the Internet of Things
Can Operations Research Bring You to the Next Level? Basics and Applications
No full textInternational audienceWe focus on some intersections between two research fields: data management and operations research (OR). More precisely, we consider how advanced OR techniques can be used to solve optimization problems occurring in databases. We recall the basics of OR, introduce a few advanced approaches and, next, present two uses cases: (i) a heuristic stemming from OR for solving the graph edit distance problem and (ii) a detailed use case on Exploratory Data Analysis (EDA) where a heuristic stemming from OR is used to cope with large instances of a database exploration optimization problem
Development of a Relative Rate Technique to Measure Criegee Intermediate Reactivity
No full textInternational audienceCriegee intermediates (CIs) play a major role in atmospheric chemistry, contributing to aerosol formation and oxidizing capacity. To assess this contribution, the kinetics of bimolecular reactions of CIs must first be established. However, few techniques are available for this purpose, limiting our understanding of CIs in the atmosphere. Accordingly, we develop a precise, economical, and highly accessible strategy for acquiring kinetic data using a relative rate approach. This method exploits highly symmetrical alkenes that produce a single type of CI through ozonolysis. By suppressing other reactive species (e.g., OH radical) formed in these systems, we probe the reactivity of CIs toward a selection of acids and alcohols, where decays of reactants were tracked using proton-transfer reaction mass spectrometry. In this proof-of-principle paper, we find that this approach can be applied to a broad variety of compounds, allowing us to access reactions with lower volatility species, extending and augmenting the CI kinetic database toward a class of reaction that may be significant for aerosol formation
B3GALT6 mutations lead to compromised connective tissue biomechanics in Ehlers-Danlos syndrome
No full textInternational audienceEhlers-Danlos syndromes (EDS) comprise a genetically and clinically heterogenous group of rare diseases that cause severe, often fatal, damage to connective tissue. The molecular basis of EDS implicates defects in extracellular matrix components, including various fibrillar collagens and glycosaminoglycans (GAGs). However, the precise pathogenic mechanisms behind EDS remain elusive. Here, we have implemented a multi-tiered approach to demonstrate the functional impact of B3GALT6 mutations on biochemical and developmental processes, ultimately leading to the spondylodysplastic subtype of EDS (spEDS), characterized by severe musculoskeletal symptoms. We show that the loss of function of β1,3-galactosyltransferase 6 (β3GalT6) is partially compensated by β1,3-glucuronosyltransferase 3 (GlcAT-I), the next enzyme in the GAG biosynthetic pathway. In addition, results from transcriptomics, collagen analysis, and biophysical experiments revealed that impaired collagen maturation, including defective glycosylation of collagen XII, contributes to altered tissue structure and biomechanics, the hallmarks of spEDS. Our findings unravel a new pathogenic mechanism of spEDS and bring us one step closer to therapeutic strategies, including cell and tissue engineering
