Portail HAL UHA (Université de Haute-Alsace)
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Comment vient l’idée ? Réflexions sur l’accompagnement vers l’invention de soi (Tome 1)Façonner sa présence : Apparaître, Demeurer, Disparaître Regard phénoménologique sur « l’être avec » qui aide l’autre à grandir (Tome 2)
No full textAmong the testimonies given at the end of a period of accompaniment, some express gratitude to such a person who was able to be present. What does such a form of recognition mean? Beyond words and actions, there is the presence that can be edifying. But how to enlighten it to better understand the fruits? We propose to try to see it as a phenomenon, unfolding in three complementary and yet decisive moments each in their own way: that of the first presence, the appearance, that of a dwelling-with where it is shared in time, the one where she slips away to make room for the other and other things. Through this essay of a phenomenological approach to presence, we will try to understand to what extent an educator in the broad sense can shape the quality of his «being-with» others, in the perspective of inspiring elements of an educational or accompanying posture. We will thus develop the idea that an art of knowing how to be present is based on an ethical intention that must inspire the search for an aesthetic specific to each of the three moments of the phenomenon, so that it can help the other to advance on his way.Parmi les témoignages rendus à la fin d’un temps d’accompagnement, certains expriment une gratitude à l’égard de telle personne qui a su être présente. Que signifie une telle formule de reconnaissance ? Au-delà des paroles, des actes, il y a la présence qui peut être édifiante. Mais comment l’éclairer pour mieux en comprendre les fruits ? Nous proposons de tenter de la regarder comme un phénomène, se déployant en trois moments complémentaires et cependant décisifs chacun à leur manière : celui de la première mise en présence, de l'apparition, celui d’un demeurer-avec où elle se partage dans le temps, celui où elle s’éclipse pour laisser place à l’autre et à d’autres choses. À travers cet essai d’une approche phénoménologique de la présence, nous tenterons de comprendre dans quelle mesure un éducateur au sens large peut façonner la qualité de son « être-avec » autrui, dans la perspective d’inspirer des éléments d'une posture éducative ou accompagnante. Nous développerons ainsi l’idée qu’un art de savoir se faire présent repose sur une intention éthique qui doit inspirer la recherche d’une esthétique propre à chacun des trois moments du phénomène, de sorte qu’elle puisse aider l’autre à avancer sur son chemin
Surface Modification of 3D‐Printed Micro‐ and Macro‐Structures via In Situ Nitroxide‐Mediated Radical Photopolymerization
No full textInternational audiencePhoto‐controlled reversible‐deactivation radical polymerization (RDRP) has recently emerged in light‐based 3D printing at macro‐ and micro‐scales, enabling the elaboration of objects with (re‐)configurable surface properties. The authors' previous work exploits nitroxide‐mediated radical photopolymerization (NMP2) in 3D micro‐printing and subsequent surface modification, by employing analkoxyamine‐based photoresist via 3D direct laser writing (DLW). However, this photoresist suffers from its low photosensitivity to wavelengths above 760 nm, limiting its suitability for commercial 3D DLW setups. To tackle these issues, a new strategy—in situ NMP2 based on a photoresist containing acommercial photoinitiator and a photosensitive‐nitroneis proposed. This photoresist is well‐suited for wavelengths commonly used by 3D DLW systems to obtain well‐defined 3D microstructures. Importantly, the in‐situ formation of alkoxyamine during fabrication allows photo‐induced surface modification of microstructures, highlighted by precise and successive surface patterning. Thesurface modification can be conducted at 800 nm or at wavelengths up to 860 nm. Subsequently, the impact of light wavelength and intensity isinvestigated to understand surface modification. The simple preparation of this novel photoresist allows facile adaptation to digital light processing for 3D macro‐printing. This work broadens the scope of photo‐controlled RDRP in 3D printing and greatly facilitates “living” 3D micro‐ and macro‐printing
Le Petit Traite de la marche en plaine : une grande exploration des pouvoirs de la poésie
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André Gide, écrivain traducteur. Suivi d’un choix de textes traduits par l’auteur
No full textInternational audienceThis book reveals an unknown aspect of Gide's, that of translator, parallel to his life as a writer. The first part recounts his life, rich and complex. The second one analyses Gide’s technique and its problems. The third one is an anthology of his translations, not easy to find today.Ce livre révèle un aspect méconnu de Gide, celui de traducteur, parallèle à sa vie d’écrivain. La première partie retrace ce parcours riche et complexe. La deuxième analyse la technique de Gide et ses problèmes. La troisième est une anthologie des textes traduits, aujourd’hui peu accessibles
La belle Polonaise ou les événements de Pologne au prisme du roman français de la fin du XVIIIe siècle (Marat, Louvet)
No full textInternational audienceThis paper examines how the events in Poland and Russia's interference are represented in Jean-Paul Marat's Les Aventures du jeune comte Potowski (The Adventures of the Young Count Potowski) and Jean-Baptiste Louvet's Les Amours du Chevalier de Faublas (The Loves of the Chevalier de Faublas), through a romantic plot that revives the myth of the virtuous Polish woman.L’étude envisage en quels termes et par quel prisme sont représentés les événements de Pologne et l'ingérence de la Russie dans Les Aventures du jeune comte Potowski de Jean-Paul Marat et Les Amours du Chevalier de Faublas de Jean-Baptiste Louvet, à la faveur d’une intrigue amoureuse réactivant le mythe de la vertueuse Polonaise
Eosin Y derivatives for visible light-mediated free-radical polymerization: Applications in 3D-photoprinting and bacterial photodynamic inactivation
No full textInternational audienceThis study reports the design and the subsequent use of mono-allylated (EY-MA) and di-allylated (EY-DA) derivatives of eosin Y (EY) as highly efficient visible light-sensitive photosensitizers (PS) of bio-based H-donor molecules (cysteamine (Cys) or N-acetyl-L-cysteine (NAC)) and an electron donor (N-methyldiethanolamine, MDEA) for free-radical and thiol-acrylate polymerizations of a biobased monomer derived from soybean oil (SOA) upon exposure to visible light. High final acrylate conversions for SOA polymerization (up to 80 %) evidence the efficient photoinitiating properties of the eosin derivatives systems under irradiation with light emitting diodes (LEDs) centred at 405, 455 and 505 nm, and outperform those obtained with EY and other common photosensitizers such as camphorquinone or benzophenone. As described by fluorescence and phosphorescence analyses, laser flash photolysis (LFP) and electron paramagnetic resonance spin-trapping (EPR-ST) experiments, EY-MA and EY-DA can react via a proton/proton-coupled electron transfer reaction with Cys (or NAC) and MDEA respectively. The efficient singlet oxygen generation of the EY-MA-based materials upon exposure to visible light leads to excellent antibacterial properties, against both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). A 3-log decrease of E. coli adhesion on the surface of the materials is observed and 100 % adhesion inhibition of S. aureus is also demonstrated. The co-polymerization of the eosin-derived PS with the polymer matrix ensures sustainable antibacterial properties against both bacteria strains upon visible light exposure as it prevents their leakage out of the polymer network. Finally, finely complex 3D structures are successfully obtained by a 3D-photoprinting technology with the investigated EY-MAbased formulation using LED@405 nm
Thermal degradations of biomass with different scales
No full textInternational audienceThe thermal degradations of biomass are usually performed first on powder to avoid the presence of thermal diffusional limits inside the sample. Different biomass have been analyzed around the world, for a long time, and under different experimental conditions. Performing thermal degradations on biomass pieces is less common, but more representative of bioprocesses involving biomass. Different experimental conditions may be applied on pieces of biomass, such as wood pellets. The presentation will focus on the differences between similar experiments performed on different scales of biomass samples. The mass and mass rate curves indeed differ when changing the scale. Gaseous and particulate emissions measured during thermal degradations on biomass pieces are certainly representative of bioprocesses
Pyrolyse et combustion de granulés sous fortes rampes de température et émissions de gaz et de particules associées
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Adsorption and Structuration of PEG Thin Films: Influence of the Substrate Chemistry
No full textInternational audienceThis study investigates polyethylene glycol (PEG) homopolymer thin film adsorption on gold surfaces of controlled surface chemistry. The conformational states of physisorbed PEG are analyzed through polarization modulation infrared reflection–absorption spectrometry (PM-IRRAS). The PM-IRRAS principle is based on specific optical selection rules allowing the detection of surface-specific FTIR response of thin polymer films on the basis of differential reflectivity at the polymer/substrate interface for p- and s-polarized light. The intensification of the electric field generated at the PEG/substrate interface for p-polarized IR light in comparison with s-polarized light permits the analysis of PEG chain anisotropy and conformational changes induced by the adsorption. Results showed that PEG adsorbs on model substrates having a rather hydrophilic character in a way that the PEG chains spread parallel to the surface. In the case of a very hydrophilic substrate, the adsorbed PEG chains are in a stable thermodynamic state which allows them to arrange and crystallize as stacked crystalline lamellae after adsorption. The surface topography and morphology of the PEG thin films were also investigated by atomic force microscopy (AFM). While in the bulk state, PEG crystallizes in the form of large spherulites; on substrates whose adsorption is favored by surface chemistry, PEG crystallizes in the form of stacked lamellae with a thickness equal to 20 nm. Conversely, on a hydrophobic substrate, the PEG chains do not crystallize and adsorption occurs in the statistical coil state
UV ‐A photodegradation of vanillin in aqueous solutions: Direct photolysis and photosensitized degradation
No full textInternational audiencePhototoxicity of skin due to the application of skincare products or fragrances is increasing from day to day, since a lot of natural extracts, with low or no toxicity in the dark, are being used in the skin exposed to solar radiation. In particular, the use of 4‐hydroxy‐3‐methoxy benzaldehyde, known as vanillin, in the pharmaceutical, food, and cosmetic industries has increased in the last years. This compound is generally considered as safe for humans, and it has been used in a wide range of applications. Significant beneficial properties, such as antioxidant, anticancer, antimicrobial, among others, have been described for vanillin, along with low toxicity. However, although vanillin is used as an ingredient in cosmetic formulations that are applied to the skin, there are few studies on the photochemistry of vanillin degradation. The degradation of vanillin in aqueous solutions exposed to UV‐A radiation (365 nm), both by direct absorption and by means of a photosensitized mechanism, was evaluated in different experimental conditions. On the bases of the experimental results, direct photodegradation of vanillin seems unlikely; however, photosensitized degradation of vanillin was observed in the presence of pterin, and vanillin dimers (6,6‐dihydroxy‐5,5‐ dimethoxy‐[1,1‐biphenyl]‐3,3‐dicarboxaldehyde) were detected as products. The mechanistic analysis indicates that the long‐lived pterin triplet excited state is responsible of vanillin degradation, while the contribution of reactive oxygen species, such as superoxide anion, hydrogen peroxide, or singlet oxygen, is negligible. The thermodynamic feasibility of the potential reactions involved in the degradation mechanism was evaluated with the Rehm–Weller equation. Considering both the thermodynamic and kinetic evidence, we proposed a mechanism for the photosensitized degradation of vanillin