Portail HAL UHA (Université de Haute-Alsace)
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A Supervised Variational Auto-encoder for Human Motion Generation Using Convolutional Neural Networks
No full textInternational audienceHuman motion generation is an important research domain addressed by a significant amount of work in the recent years, with the availability of new datasets captured either from sensors or cameras. Most of the existing approaches are based on the Variational Auto-Encoder (VAE) architecture using Recurrent Neural Networks (RNN) or Transformers. In this paper, we propose to handle human motion sequences as Multivariate Time Series (MTS), and construct a VAE based on Convolutional Neural Networks (CNN). Furthermore, the proposed architecture uses an action classification task to add the conditioning aspect to the generative model. Our proposed Supervised VAE (SVAE) achieves competitive results on the HumanAct12 dataset, both in terms of quality and diversity of the generated sequences
Quantum-confined bismuth iodide perovskite nanocrystals in mesoporous matrices
No full textInternational audienceBismuth iodide perovskite nanocrystals are considered a viable alternative to the Pb halide ones due to their reduced toxicity and increased stability. However, it is still challenging to fabricate nanocrystals with a small and controlled size, and their electronic properties are not well understood. Here, we propose the growth of Bi iodide perovskite nanocrystals using different mesoporous silica with ordered pores of controlled diameter as templates. We obtain a series of confined Cs3Bi2I9 and MA3Bi2I9 perovskites with diameters of 2.3, 3.7, 7.4, and 9.2 nm, and precise size control. The complex absorption spectra of the encapsulated perovskites cannot be properly fitted using classical Tauc or Elliott formalisms. By fitting the spectra with a modified Elliott formula, the bandgap values and exciton binding energies (70-400 meV) could be extracted. The calculated bandgaps scale with the pore sizes. Using a combined experimental and theoretical approach, we demonstrate for the first time quantum confinement in 0D Bi-iodide perovskite nanocrystals
Effective removal of toxic dye from wastewater via advanced modified magnetic sepiolite using combined surfactants SDS/CTAB/Fe<sub>3</sub>O<sub>4</sub>@Sep: Empirical and computational analysis studies
No full textInternational audienceIn the present era, the elimination of hazardous dyes from wastewater has emerged as a paramount concern, captivating the interest of scientists globally because their detrimental effect on human health. Adsorption, a well-established and effective separation process, is commonly employed for eliminating various harmful organic pollutants from water, particularly toxic dyes. In this study, a novel magnetic organo-composite was synthesized through an environmentally friendly and easily implementable approach. Subsequently, various analytical techniques, including XRD, FT-IR, SEM, and EDX, were utilized to scrutinize the structure and morphology of the adsorbent. The as-prepared adsorbent demonstrated remarkable efficiency in rapidly removing malachite green dye from aqueous solutions, attaining a peak adsorption capacity of 227.40 mg g−1. Furthermore, several factors affecting the adsorption process were investigated, including adsorbent dosage, medium pH, initial dye concentration, and contact time. The examination of adsorption kinetics data indicated that the process adhered to a pseudo-second-order model (R2 = 0.97), implying that chemisorption constituted the controlling step in the reaction. Additionally, the experimental adsorption isotherms exhibited a close fit to the Langmuir model (R2 = 0.98). Crucially, the SDS/CTAB/Fe3O4@Sep magnetic organo-nanocomposite adsorbent exhibited the capacity for multiple reuses, maintaining its effectiveness over five cycles without notable activity decline. Consequently, the synthesized organo-composite appears to show potential as an effective adsorbent for eliminating harmful cationic dyes present in wastewater. Molecular dynamics (MD) simulations, employing Monte Carlo adsorption locator simulation (MCL) calculations, further supported the elevated adsorption of SDS/CTAB on Sep, Fe3O4 on SDS/CTAB@Sep, and MG molecules on SDS/CTAB/Fe3O4@Sep due to their negative adsorptions
High-pressure intrusion of double salt aqueous solution in pure silica chabazite: searching for cation selectivity
No full textInternational audienceHeterogeneous lyophobic systems (HLSs), i.e. systems composed of a nanoporous solid and a non-wetting liquid, have attracted much attention as promising candidates for innovative mechanical energy storage and dissipation devices. In this work, a new HLS based on a pure silica chabazite (Si-CHA) and a ternary electrolyte solution (KCl + CaCl 2 ) is studied from porosimetric and crystallographic points of view. The combined approach of this study has been fundamental in unravelling the properties of the system. The porosimetric experiments allowed the determination of the energetic behaviour, while high-pressure in situ crystallographic analyses helped elucidate the mechanism of intrusion. The results are compared with those obtained for systems involving the same zeolite but intruded with solutions containing only single salts (CaCl 2 or KCl). The porosimetric results of the three Si-CHA systems intruded by simple and complex electrolyte solutions (KCl 2 M , CaCl 2 2 M and the mixture KCl 1 M + CaCl 2 1 M ) suggest that the intrusion pressure is mainly influenced by the nature of the cations. The CaCl 2 2 M solution shows the highest intrusion pressure and KCl 2 M the lowest, whereas the mixture KCl 1 M + CaCl 2 1 M is almost in the middle. These differences are probably related to the higher hydration enthalpy and Gibbs energy of Ca 2+ compared with those of K + . It has been demonstrated that partial ion desolvation is needed to promote the penetration of the species, and a higher solvation energy requires higher pressure. The `intermediate' value of intrusion pressure shown by the complex electrolyte solution arises from the fact that, statistically, the second/third solvation cation shells can be assumed to be partially shared between K + and Ca 2+ . The stronger interaction of Ca 2+ with H 2 O molecules thus also influences the desolvation of K + , increasing the pressure needed to activate the process compared with the pure KCl 2 M solution. This is confirmed by the structural investigation, which shows that at the beginning of intrusion only K + , Cl − and H 2 O penetrate the pores, whereas the intrusion of Ca 2+ requires higher pressure, in agreement with the hydration enthalpies of the two cations
Accidents de tramway : la véritable réforme, toujours sur une voie de garage
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Multiplex Evaluation of Biointerface-Targeting Abilities and Affinity of Synthetized Nanoparticles—A Step Towards Improved Nanoplatforms for Biomedical Applications
No full textInternational audienceTo obtain versatile nanoplatforms comparable for various bio-applications, synthesis and functionalization of two inorganic nanoparticles (NPs), i.e., gold (AuNPs) and iron oxide (SPIONs), are described for different NP diameters. Chosen ligands have adapted chemical function to graft to the surfaces of the NPs (thiols and phosphonates, respectively) and the identical frequently used external carboxyl group for comparison of the NPs’ material effect on their final behavior. To further evaluate molecular length effect, AuNPs are functionalized by different ligands. Numerous characterizations highlight the colloidal stability when grafting organic molecules on NPs. The potentiality of the functionalized NPs to react efficiently with a protein monolayer is finally evaluated by grafting them on a protein covered chip, characterized by atomic force microscopy. Comparison of the NPs’ surface densities and measured heights enable observation of different NPs’ reactivity and infer the influence of the inorganic core material, as well as the NPs’ size and ligand length. AuNPs have higher affinities to biomolecules, especially when covered by shorter ligands. NP ligands should be chosen not only based on their length but also on their chemical chain, which affects proteic layer interactions. This original multiplex comparison method using AFM is of great interest to screen the effects of used NP materials and functionalization when developing theranostic nanoplatforms
La figlia prodiga/L’enfant prodigue: «ritorni» di André Gide in Alice Ceresa
No full textInternational audienceWithin the broader framework of research on the reception of Alice Ceresa in France and the relationship of the Ticinese writer with the French intellectual milieu, the name of André Gide, Nobel Prize winner in literature in 1947, has emerged as a fundamental reference point, especially in the choice to revisit the famous parable of the prodigal son. The affinity between the titles of two works, La figlia prodiga by Alice Ceresa, published in 1967, and Le retour de l’enfant prodigue by André Gide, dating back to 1907, has further highlighted the need for a close comparison of the two texts and their respective poetics. Both works refer to a common archetype, the biblical parable, found only in the Gospel of Luke (15:11-32), which boasts an extraordinary legacy in the history of literature, to the extent that Charles Dickens called it “the greatest short story ever written” (DI ROCCO ― MONTORI 2020, 10). Beyond their shared intertext, this essay aims to explore the connections between Ceresa’s text and Gide’s, bringing together different areas of research: Ceresa studies, Gide studies, reception studies, and the hermeneutics of literature. The following pages seek to highlight some points of contact and then define the extent of André Gide’s influence on the Swiss writer, following the thread of unpublished documents from the Ceresa Archive (Swiss National Library) and the publication of Ceresa’s first novel by Einaudi in 1967.Nell’ambito più ampio delle ricerche sulla ricezione di Alice Ceresa in Francia e sui rapporti della scrittrice ticinese con l’ambiente intellettuale francese, il nome di André Gide, Premio Nobel per la letteratura nel 1947, si è imposto come un punto di riferimento fondamentale, soprattutto nella scelta di riprendere la celebre parabola del figliol prodigo. L’affinità tra i titoli di due opere, La figlia prodiga di Alice Ceresa, pubblicato nel 1967, e Le retour de l’enfant prodigue di André Gide, risalente al 1907, ha inoltre imposto la necessità di mettere a confronto serrato due testi e due poetiche. Entrambe le opere rinviano a un archetipo comune, ovvero il racconto biblico, presente solo nel Vangelo di Luca (15, 11-32), che vanta una straordinaria fortuna nella storia della letteratura, al punto che Charles Dickens lo definisce «the greatest short story ever written» (DI ROCCO ― MONTORI 2020, 10). Al di là dell’intertesto comune, il presente saggio si propone di indagare le relazioni che il testo di Ceresa intrattiene con quello di Gide, facendo incontrare ambiti di ricerca diversi: gli studi ceresiani, gli studi gidiani, gli studi sulla ricezione e l’ermeneutica della letteratura. Le pagine che seguono vogliono dunque segnalare alcuni punti di contatto per poi definire i margini di influenza che André Gide ha avuto sulla scrittrice svizzera, seguendo il filo rosso dei documenti inediti del Fondo Ceresa (Biblioteca nazionale svizzera) e della pubblicazione del primo romanzo della scrittrice nel 1967 per Einaudi
