References of "Mathis, François"
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See detailL'utilisation du fer dans la construction médiévale mosane : explications et premiers repères d'une évolution
Maggi, Christophe ULg; Pagès, Gaspard ULg; Hoffsummer, Patrick ULg et al

Conference (2011, April 11)

The development of a new comparative approach establishing a link between the evaluation of the quantity of barks used in a roof frame and the volume of wood present in this same attic allows the ... [more ▼]

The development of a new comparative approach establishing a link between the evaluation of the quantity of barks used in a roof frame and the volume of wood present in this same attic allows the acquisition of essential information for the apprehension of the economical, the technical and the social contexts in which a timber frame was drawn up. By carrying out this kind of comparison in a systematic way in about thirty attics of religious buildings dispersed in the Walloon region (Belgium), the evolution of these contexts develops step by step since 12th until 18thcentury and highlights phenomena which influence the methods of constructions of the carpenters, like the appearance of the saw or the rarefaction of the forest resources. The confrontation of this result with the evolution of the volume of iron considered in the attics reveals the catch of importance of this material in function of the time and of the architectural principles. Iron appears in the roof frames of our areas in the same time that the advent of the Gothic architecture in link with the increase of the roof’s dimensions. Its employment generalizes then knows a real expansion at the 17th century because of the rarefaction of the forest resources but also because the preindustrial techniques allow it. [less ▲]

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See detailCouches d'oxydation et patines intentionnelles des bronzes
Mathis, François ULg

Book published by Editions universitaires europeennes (2011)

Les couches d'oxydation présentes à la surface des alliages cuivreux d'objets du patrimoine culturel sont très riches d'informations. Elles peuvent renseigner sur l'aspect d'origine de l'objet et sur son ... [more ▼]

Les couches d'oxydation présentes à la surface des alliages cuivreux d'objets du patrimoine culturel sont très riches d'informations. Elles peuvent renseigner sur l'aspect d'origine de l'objet et sur son état de conservation. Elles sont souvent de nature très complexe et leur analyse est très délicate car elle est soumise à des contraintes sévères de préservation. Nous nous sommes intéressés aux couches provenant d'oxydations à haute température et aux patines intentionnelles antiques. L'oxydation à haute température du système cuivre-étain a été étudiée de manière approfondie et nous avons proposé un modèle mettant en évidence le rôle inhibiteur de l'étain. Nous avons également étudié les patines intentionnelles antiques qui sont le résultat de traitements chimiques effectués par l'artisan pour modifier l'aspect et la couleur du matériau métallique. Pour cela nous avons analysé un corpus exceptionnel d'objets de musée. Ces analyses ont permis de réaliser des avancées importantes dans la connaissance de ces objets et de ces techniques, mais aussi dans le domaine de l'histoire des techniques et stylistique dans l'Antiquité méditerranéenne. [less ▲]

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See detailTiO2 multilayer thick films (up to 4 μm) with ordered mesoporosity: Influence of template on the film mesostructure and use as high efficiency photoelectrode in DSSCs
Dewalque, Jennifer ULg; Cloots, Rudi ULg; Mathis, François ULg et al

in Journal of Materials Chemistry (2011), 21(20), 7356-7363

Mesoporous templated anatase thin films are very promising materials to act as photoelectrode in dye-sensitized solar cell. Templated-assisted dip-coating techniques are used to obtain thin films with ... [more ▼]

Mesoporous templated anatase thin films are very promising materials to act as photoelectrode in dye-sensitized solar cell. Templated-assisted dip-coating techniques are used to obtain thin films with ordered porosity. However, monolayer films are very thin and suffer from a low quantity of active material, leading to poor photovoltaic performances. In this paper, a dip-coating-based multilayer deposition technique is reported. First, we have studied the influence of the template on the film organization and porosity in terms of long-range order, percentage of porosity, pore size and pores connectivity. Different techniques such as transmission electron microscopy (TEM), atmospheric poroellipsometry (AEP) and UV-visible absorption spectroscopy (UV-vis.) have been used to describe the microstructural features of the films with a thickness of 1 µm. The film exhibiting the highest dye loading was selected and its thickness gradually increased up to 4 µm. Finally, the photovoltaic performances of the thick films (1 to 4 µm) have been evaluated in combination with the N-719 dye and show excellent efficiency (6.1%) when compared to values reported in the literature. Such mesostructured films are compared in terms of photovoltaic performance with TiO2 nanoparticles films, generally used in DSSC. [less ▲]

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See detailTiO2 mesoporous thin films studied by Atmospheric Ellipsometric Porosimetry: A case of contamination
Dubreuil, Olivier ULg; Dewalque, Jennifer ULg; Chene, Grégoire ULg et al

in Microporous & Mesoporous Materials (2011), 147

Anatase mesoporous TiO2 thin films are frequently prepared by surfactant templating to control porosity development and Atmospheric Ellipsometric Porosimetry is a reliable and fast technique allowing the ... [more ▼]

Anatase mesoporous TiO2 thin films are frequently prepared by surfactant templating to control porosity development and Atmospheric Ellipsometric Porosimetry is a reliable and fast technique allowing the determination of the porosity of such films. After prolonged exposition to high-vacuum (6×10-6 mbar), the films porosity exhibits a degraded behavior during porosimetric measurements, indicating a vacuum-induced modification. The main effect resulting from such exposition to high-vacuum is a wet- tability modification of the films, resulting in an increase of the hydrophobic character of the TiO2 surface. This evolution induces non-correct results in porosimetric measurements due to the fact that the contact angle parameter needed to calculate the pore size distribution is highly different from the reference films. A surface contamination explains such modifications and a restoration of the films is obtained by using ultraviolet treatment. [less ▲]

Detailed reference viewed: 106 (38 ULg)
See detailLes grenats dans l’orfèvrerie mérovingienne
Mathis, François ULg; Vrielynck, Olivier; Annaert, Henrica et al

Conference (2010, August)

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See detailDendrochronology to date mettalic reinforcements in roof frames
Maggi, Christophe ULg; Pagès, Gaspard ULg; Hoffsummer, Patrick ULg et al

Poster (2010, June 17)

Studies about metallic reinforcements in historical monuments multiply themselves. Thanks to building archaeology and dendrochronology, we are able to determine the archaeological contexts to which the ... [more ▼]

Studies about metallic reinforcements in historical monuments multiply themselves. Thanks to building archaeology and dendrochronology, we are able to determine the archaeological contexts to which the metallic elements belong and to date them. One of the objectives of the research is to list the different appearances of iron in roof frames and to identify the function of each. At the end, the principal aim is to create a typo-chronological inventory which will index all the iron reinforcements met in medieval roof frames of the Meuse basin (Belgium). [less ▲]

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See detailGlass production in Merovingian time
Van Wersch, Line ULg; Mathis, François ULg; Othmane, G. et al

Poster (2010, May)

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See detailIntentional patina of metal archaeological artefacts; a non-destructive investigation of Egyptian and Roman museum treasures
Aucouturier, Marc; Mathis, François ULg; Robcis, Dominique et al

in Corrosion Engineering, Science & Technology (2010), 45(5), 314-321

This paper describes microstructural analyses by X-ray portable diffraction and microdiffraction on intentional patina of the bronze museum objects from antique Egypt and the Roman Empire. They bring ... [more ▼]

This paper describes microstructural analyses by X-ray portable diffraction and microdiffraction on intentional patina of the bronze museum objects from antique Egypt and the Roman Empire. They bring evidence of the presence in the true black bronze patinas of metallic gold and/or silver presumably as nanoparticles. Three other Egyptian patinas not belonging to black bronze are characterised. Apparent black patination on a Roman scalpel handle is discussed. The discovery of a new patination procedure on Roman artefacts from the Louvre museum is also related, based on intentional high temperature oxidation to obtain a dark patina on a lead bronze object. A presence of lead carbonate cerussite is an important observation. [less ▲]

Detailed reference viewed: 27 (3 ULg)