Portail HAL UHA (Université de Haute-Alsace)
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Le passage de la voie sèche à la voie humide. Le cas des argents monnayés et des argents métalliques
No full textInternational audienceThanks to the combined contributions of metallurgical and chemical treatises and anthropology, it is possible to understand the transition from dry to wet analysis. This development is due to the work of Gay-Lussac. It was motivated by the search for precision in the determination of silver in mints. The use of the wet method did not mean the disappearance of the earlier process. Using recent examples from two different environments, a mining context and an urban workshop, we show why a technique rooted in the medieval world, whose imperfections have been identified, has not been abandoned in favour of a more precise assaying technique. Beyond the desire for precision, choosing one or the other depends primarily on how the analytical result is used and the economic sector in which it is applied.Grâce aux apports combinés des traités métallurgiques et de chimie et de l’anthropologie, il est possible d’appréhender la question du passage du procédé d’analyse par voie sèche à celui par voie humide. Cette évolution, que l’on doit aux travaux de Gay-Lussac, a été motivée par une recherche de précision dans le dosage de l’argent des ateliers monétaires enclenchée dès le xviiie siècle. L’usage de la voie humide n’a pas entrainé la disparition du procédé antérieur. À l’aide de deux exemples actuels pris dans des environnements éloignés, un contexte minier et un atelier urbain, nous montrons pourquoi une technique plongeant ses racines dans le monde médiéval et dont les défauts sont identifiés n’a pas été délaissée au profit d’une technique de dosage plus précise. Au-delà de la recherche de précision, le choix de l’une ou de l’autre méthode repose d’abord sur l’usage qui est fait du résultat analytique et de la sphère économique dans lequel il s’inscrit
Impact of easy-care and softener treatments on fabric frictional noise properties: a study on two protective fabrics
No full textInternational audienceThis research aimed to reduce fabric frictional noise to enhance wearing comfort, as such noise can be bothersome. This goal was achieved through chemical surface treatments, specifically cross-linker treatment and silicone softener treatment. Frictional noise from the treated fabrics was generated, recorded, and analyzed using a frictional noise generator, fast Fourier transform, and sixth-band analysis to determine the total noise level. A novel aspect of this work is the use of psychoacoustic characterization to evaluate the fabric frictional noise by calculating Zwicker’s parameters using the Brüel and Kjær application. In addition, the mechanical properties were tested using the Kawabata compression and surface testers, with data comparison achieved using Student’s t-test. The results showed that softeners are more effective than cross-linkers in reducing the total frictional noise level, loudness, and fluctuation strength. However, cross-linkers are better at reducing sharpness. Neither treatment affected the roughness of the frictional noise. In summary, both easy-care and softener treatments help reduce discomfort and produce less loud and sharp fabric frictional noise
Impact of emissive point distribution density in a retinal projection near-eye display
No full textInternational audienceWe investigate an unconventional concept of near-eye display based on sparse aperture imaging principles. In this original approach, a pixel is projected onto the retina through the emission of emissive points randomly distributed on the surface of the glass. In this contribution, we evaluate the impact of the emissive point distribution characteristics on the imaging performances. We highlight the central role of the emissive point density on the contrast of the image projected onto the retinal plane. This result leads us to reconsider our initial display architecture
Essai sur le patrimoine des sciences
No full textInternational audienceThe author invites us to explore the heritage of science through its seven dimensions. The first is that of science as a decipherer, revealer and builder of heritage. This is true of the very places where research is carried out, where a biotope or geotope is encountered. But to build its heritage, science has accumulated collections of objects, extracted from nature in its raw state (a plant from a herbarium, a remarkable mineral or even databases of living organisms) or modified or even reproduced, elementary 'increments' of heritage (a naturalised animal, the glass jellyfish of the Blaschka family, etc,). In addition, those involved in science use instruments for research (whose obsolescence is a source of sacredness, such as those on display at the Optical Instrumentation Museum in Biesheim). This research is carried out on premises dedicated to the practice of science and its transmission (a university, an observatory, or Goethe's house in Weimar). In this vein, the author studies the archives of science produced by the researchers themselves, their correspondents and their supervisory bodies, and which lead to the memory of scientists. Although the achievements of science in all its dimensions are seen in terms of the heritage of mankind, it is in fact a heritage of a very special nature, since it is perpetually renewing itself: a malleable heritage, in permanent generation.L’auteur invite à explorer le patrimoine des sciences à travers ses sept dimensions. La première campe la science comme décrypteur, révélateur et constructeur de patrimoine. Il en va ainsi des lieux même du terrain, de la rencontre d’un biotope ou d’un géotope. Mais pour se construire les sciences ont accumulé des collections d’objets, extraits de la nature à l’état brut (une plante d’herbier, un minéral remarquable ou encore les banques du vivant…) ou modifié voire reproduit, « incréments » élémentaires de patrimoine (un animal naturalisé, les méduses en verre des Blaschka…). Par ailleurs, les acteurs des sciences se servent d’instruments pour la recherche (dont l’obsolescence est source de sacralisation, tels ceux présentés au musée d’instrumentation optique de Biesheim). Celle-ci s’effectue dans des locaux dévolus à la pratique de la science et de sa communication (une université, un observatoire, ou encore la maison de Goethe à Weimar). Poursuivant cette déclinaison, l’auteur en arrive aux archives des sciences, produites par les chercheurs eux-mêmes, leurs correspondants, leurs organismes de tutelle, et qui conduisent à la mémoire de savants. Si les acquis de la science dans toute sa dimension sont perçus en termes de patrimoine de l’humanité, il s’agit en fait d’un patrimoine d’une nature très particulière puisqu’il se renouvelle perpétuellement sur lui-même : un patrimoine malléable, en génération permanente
Les campagnes télévisuelles dans l'expérience de marque : un vecteur potentiel d'authenticité au profit du capital de marque
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Les effets normatifs comparés de l’éco-spiritualité et de la religiosité sur les comportements de recyclage des restes alimentaires dans le foyer.
No full textNational audienceFaced with the environmental problems posed by food waste, recycling food leftovers within the household is a solution to be encouraged. Within the framework of the model of social norms activation, the present study examines the compared effects of intrinsic religiosity and eco-spirituality of consumers in activating an injunctive social norm favorable to food waste recycling behaviors within the household. The results of a survey conducted among over 500 consumers representative of the French population show that only eco-spirituality would be likely to activate this injunctive norm, thus leading to food leftovers recycling behaviors; the effect of the norm on behaviors being partially mediated by anticipated guilt. Societal recommendations are drawn from these results.Face aux problèmes environnementaux posés par le gaspillage alimentaire, le recyclage des restes alimentaires dans le cadre du foyer est une solution à encourager. Dans le cadre du modèle d’activation des normes sociales, ce travail s’interroge sur les effets comparés de la religiosité intrinsèque et de l’éco-spiritualité des consommateurs pour activer une norme sociale injonctive favorable aux comportements de recyclage des restes alimentaires dans le foyer. Les résultats d’une enquête réalisée auprès de plus de 500 consommateurs représentatifs de la population française montrent que seule l’éco-spiritualité serait susceptible d’activer cette norme injonctive, entrainant ainsi des comportements de consommation des restes alimentaires ; l’effet de la norme sur les comportements étant partiellement médiatisé par la culpabilité anticipée. Des préconisations sociétales sont tirées de ces résultats
Inverse problems based self-calibrated reconstruction for tomographic diffractive microscopy
No full textInternational audienceIn this work we propose an inverse problems based iterative reconstruction method for tomographic diffractive microscopy, involving measurements in off-axis configuration. More precisely, we propose a strategy that aims to eliminate reconstruction errors that can be caused by perturbations in the illumination wave of the reference arm. Our original contribution is to build the inverse problem considering as unknowns both the targeted 3D sample map and the perturbation map, that are jointly reconstructed and unmixed during the iterative process. This self-calibration process is rendered possible by the multiplicity of sample observations from multiple views, where the reference perturbed background remains invariant. We validate the feasibility of our approach on reconstructions from simulated data under different experimental conditions
Smart Design of Highly Luminescent Octupolar Mesogenic Tetra styryl-alkynyl Bipyrimidine-Based Chromophores Presenting Non-Linear Optical Properties
No full textInternational audienceThe research investigations reported in this paper focuses on the influence of rational design on the photophysical properties of new all-organic multifunctional chromophores. Nonlinear optical (NLO) behavior, optical properties and mesogenicity of several new -conjugated octupolar chromophores, presenting alkoxy styryl-alkynyl donor groups carrying aliphatic achiral and chiral chains in the 3,4 / 3,5 / 2,4 position, connected to electron-accepting 2,2-bipyrimidine cores are investigated by various techniques (light-transmission measurements, polarized-light optical microscopy, differential scanning calorimetry measurements, twophoton excited fluorescence and Hyper Rayleigh Scattering). The mesogenic properties were investigated depending on the position of the alkoxy chain and the 3,4 derivatives were found to exhibit liquid-crystal with the formation columnar phases over large temperature ranges which were confirmed by small-angle X-ray scattering analysis. All the molecules exhibit exceptional high fluorescence quantum yields values around 80 % and excellent nonlinear optical properties
Renaissance de l'élément moral en matière de prise illégale d'intérêts
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New monomers or co-monomers based on the alkoxyfuranone Scaffold: Toward new alternatives to Petroleum-Based structures
No full textInternational audienceOver the past decade, the circular economy has become a key component of sustainability due to environmental issues and more stringent environmental regulations. In this connection, the valuation of bio-based monomers possessing innovative structures remains an important challenge. Furthermore, several goals must be achieved: 1) the homopolymerization of such bio-based monomers by free radical photopolymerization which requires small energy inputs with limited emission of volatile organic compounds (COV) and 2) their copolymerization with Elium® thermoplastic resins to increase biogenic carbon in these novel low-viscosity methacrylic resins developed by Arkema. The challenge will be, in this context, to maximize the biomass carbon content while maintaining or even surpassing the properties exhibited by their petrochemical counterpart. In this work, a series of alkoxyfuranones derived from furfural have been synthesized. The four alkoxyfuranones (AF1, AF2, AF3 and AF4) varying by the functionality of the side chains (but-3-en-1-yl, acrylate, isopropyl and ethyl) attached via acetalization of the 5-hydroxy-2(5H)-furanone were studied as potential monomers or co-monomers for free radical polymerization. The synthesis of AF1 and AF2 has never been reported in the literature. The homopolymerization of two of them (AF1 and AF2) was successfully achieved, but only one led to a high-glass transition temperature (T) bio-based polymer. On the other hand, copolymerization with Elium® thermoplastic resins was obtained with different ratios of AF2 as a co-monomer. As a result, the expected gain value, such as faster photopolymerization was successfully obtained. Nevertheless, the copolymerization doesn’t lead to obtaining high-T polymer