Pulsed laser photopolymerization: Kinetics, modeling and application in holography

International audienc

Influencer marketing: The role of Z followers’ emotions

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Influence of cation nature on high pressure intrusion of aqueous salt solutions in pure silica MFI-type zeolite

International audienceHigh pressure intrusion-extrusion of water and aqueous salt solutions in hydrophobic porous solids such as pure silica zeolites (zeosils) is a promising way to absorb and store mech. energy. The intrusion pressure has already been shown to be increased with salt concentration, but the influence of cation nature is not yet fully understood. The intrusion-extrusion experiments of aqueous chloride solutions of alkali, alk.-earth and transition metals (MCln, where Mn+ = Li+, Na+, K+, Rb+, Cs+, Ca2+, Mg2+, Sr2+, Al3+, Mn2+, Ni2+ Co2+, Cu2+, Zn2+, Cd2+) in MFI-type zeosil (silicalite-1) have been performed to study this effect. In contrast to the anions, the reported results indicate that the cation nature does not have a significant influence on intrusion behavior. All the systems demonstrate a spring behavior with fully reversible intrusion except the ones with highly concentrated ZnCl2 and CsCl solutions, where a small part of the liquid remains trapped in the pores in the first intrusion-extrusion cycle. At fixed H2O/salt molar ratio, a strong influence of cation nature on intrusion pressure is observed For alkali, alk.-earth metal and aluminum cations, the intrusion pressure rises with cation charge, whereas the increase of cation size leads to a pressure decrease. These trends are also in agreement with cation hydration enthalpy value for alkali and alk.-earth metal cations, but no correlation is observed for the most part of the transition metal ones except Zn and Cd

Development of White Light-Emitting Textiles Using Inorganic Phosphor-Loaded Photopolymers for Potential Lighting Applications

International audienceThe development of flexible textile-based lighting systems remains challenging, usually requiring the combination of light-emitting diodes (LEDs) with polymer optical fibers to achieve 2 large emission areas. However, the overall emission remains point-based, leading to possible glare issues and shadowed zones. In this context, the present work proposes the development of light-emitting textiles that uniformly distribute white light when excited by a blue LED source. Simple cotton substrates were coated with a flexible photoluminescent phosphor-loaded polymer composite. The yellow and/or red phosphors were efficiently incorporated into the polymer matrix via a fast and easy-to-implement UV-induced polymerization reaction, conducted in air and in the absence of any toxic organic solvents. Under blue light, the yellow phosphor-coated textile produced cold white light but the color temperature was easily tuned to warmer nuances by adjusting the amount of red-emitting phosphor, with high color rendering indexes (>70) and luminance values over 500 cd/m². Stability and structural measurements were then carried out to assess possible scale-up options. The versatility of the polymer matrix also expanded the possible applications to 2D surface functionalization and 3D printing

A greedy algorithm for the estimation of instantaneous frequencies in the time-frequency plane

In this paper, we propose to study mode recovery in the time-frequency plane from a parametric perspective. Formulating the inverse problem to solve, we seek to retrieve the number of components as well as their parameter. To that end, we propose a greedy algorithm that iteratively add new components to the solution, while providing at each step a coarse-to-fine optimization to avoid local minima. Numerical results allows to assess the performance of our method, with respect to component and instantaneous frequency retrieval.Dans cette contribution, nous proposons d'étudier l'estimation de modes dans le plan temps-fréquence en adoptant un modèle paramétrique. Le problème inverse à résoudre est celui de l'estimation du nombre, et des paramètres, des composantes. Pour le résoudre, nous proposons un algorithme glouton qui ajoute de manière itérative des composantes, tout en effectuant une optimisation coarse-to-fine à chaque étape. Les résultats numériques permettent d'illustrer les performances de la méthode proposée, pour la restitution des composantes comme des fréquences instantanées

Characterizing particulate and condensable emissions from a wood burning insert

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In Situ Synthesis of Molecularly Imprinted Polymers by Near-Field Photopolymerization for Ultrasensitive PFOA Plasmonic Plastic Fiber Optic Sensors

International audiencePer-and polyfluoroalkylated substances (PFAS), in particular perfluorooctanoic acid (PFOA), are persistent environmental pollutants that constitute major health risks due to their toxicity and bioaccumulation potential. Their detection is therefore a crucial and immediate challenge.This study presents an innovative nanofabrication approach for preparing highly sensitive sensors to detect PFOA. This approach is based on molecularly imprinted polymers (MIPs) obtained by near-field photopolymerization (NFPP). These MIPs are grafted onto a gold-coated plastic optical fiber (POF), thanks to near-field light enhancement by surface plasmon resonance (SPR). This approach enables nanoscale functionalization of POFs by MIPs, promoting accessibility to specific sites and optimizing coupling with surface plasmon. By adjusting the thickness of the MIPs through light irradiation, scalable limits of detection (LOD) from 53 aM to 6.3 pM were obtained, enabling coverage of concentrations ranging from attomolar to nanomolar scales, with a response time of only 10 minutes. POF@MIP sensors also show excellent selectivity, with no response in the presence of two analogues even at concentrations 100 times higher than that of PFOA. This PFAS sensor, exploiting SPR, is the first to achieve an LOD in the attomolar range, paving the way for advanced monitoring of these environmental contaminants.</div

How deep is your love? Explore user attachment to digital sharing platforms

International audienceWhile sharing platforms have shown their continued rise and growing importance in recent years, they now operate in competitive market conditions and a changing environment: scam issues (Vinted platform), legal evolution (Airbnb issue). Today, it is becoming essential for digital sharing platforms to develop strong and durable relationships with users. In this context, platform attachment is the key to success (Li et al., 2022). This study explores a concept widely used in marketing literature, brand attachment, within the context of sharing platforms. A qualitative study was conducted among users of the HomeExchange platform to identify andbetter understand the platform attachment construct. Our exploratory study reveals five user profiles and suggests that while user experiences impact satisfaction, which leads to platform attachment, user compatibility remains the key factor. This study contributes to the marketing literature by investigating the role of user attachment to sharing platforms and provides a holistic understanding of how platform attachment develops

Confirmation de la compétence extraterritoriale de l'AMF en matière d'abus de marché

International audienceNote sous Cour de cassation, com., 12 mars 2025, no 23-20.432 (FS-B

Devoir de vigilance : confirmation de la condamnation de La Poste pour insuffisance de son plan de vigilance - CA Paris, Pôle 5 chambre 12, 17 juin 2025, n° 24/05193

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