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Matériaux hybrides et nanostructurés
(11) Production(s) de l'année 2018
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Gas slippage in fractal porous material 
Auteur(s): Woignier Thierry, Anez Liz, Etienne-Calas S., Primera Juan
(Article) Publié:
Journal Of Natural Gas Science And Engineering, vol. 57 p.11-20 (2018)
Ref HAL: hal-01921072_v1
DOI: 10.1016/j.jngse.2018.06.043
WoS: WOS:000444521300002
Exporter : BibTex | endNote
3 Citations
Résumé: Gas flow through porous media in the slip flow regime is of great significance for the exploitation of undergroundnatural gas and oil. The gas slip effect in porous media plays a very important role in different engineeringfields, because gas slippage is involved in the determination of gas apparent permeability. In thisstudy, the gas slip effect was investigated in model microporous materials: composite silica aerogels. We measuredgas and water permeability in sets of nano composite silica aerogels, fractal materials with a high porevolume and tortuosity, and low permeability. The observed difference in gas and water permeability was analyzedfrom the point of view of the slip regime (Klinkenberg correction), b) and transition regime (Knudsencorrection). The effect of structural parameters of porous media (pore volume, tortuosity, fractal features) on theKlinkenberg and Knudsen corrections are discussed and the different models proposed in the literature aretested. Experimental results showed that: (1) gas permeability is almost two orders of magnitude greater thanwater permeability, (2) Klinkenberg and Knudsen corrections increase with decreasing permeability, (3) theKnudsen corrections calculated from the literature models were almost one order of magnitude lower thanexperimental data, (4) we also tested the Klinkenberg approach for tortuous and fractal porous media, the fractalmodel with second-order slip improved the accuracy of the prediction and agree with the experimental results.
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Mechanical behaviour of aerogels and composite aerogels submitted to specific penetration tests
Auteur(s): Faivre A., Duffours L., Colombel P., Despetis F.
(Article) Publié:
Journal Of Sol-Gel Science And Technology, vol. p. (2018)
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Dynamics of the S(1D)+o-D2 --> SD+D reaction at low collision energies: revisiting the SH2 system
Auteur(s): Lara Manuel, Chefdeville Simon, Larregaray Pascal, Bonnet L., Launay Jean-Michel, Costes Michel, Naulin Christian, Jambrina Pablo G, Aoiz F Javier, Bergeat Astrid
(Affiches/Poster)
MOLEC 2018 (Dinard, FR), 2018-08-26
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Chemical & Nano-mechanical Study of Artificial Human Enamel Subsurface Lesions
Auteur(s): Al-Obaidi R., Salehi H., Desoutter A., Bonnet L., Etienne P., Terrer E., Jacquot B., Levallois B., Tassery Hervé, Cuisinier Frédéric
(Article) Publié:
Scientific Reports, vol. 8 p.4047 (2018)
Texte intégral en Openaccess : 
Ref HAL: hal-01767245_v1
DOI: 10.1038/s41598-018-22459-7
WoS: WOS:000426643600011
Exporter : BibTex | endNote
4 Citations
Résumé: White lesions represent an early phase of caries formation. 20 human sound premolars were subjected to pH cycling procedure to induce subsurface lesions (SLs) in vitro. In addition, 2 teeth with naturally developed white spot lesions (WSLs) were used as references. All specimens characterized by confocal Raman microscopy being used for the first time in examining white & subsurface lesions and providing a high resolution chemical and morphological map based on phosphate peak intensity alterations at 960 cm−1. Nanoindentation technique was used to measure Hardness (H) and Young’s modulus (E) of enamel. Phosphate map of examined samples exhibited presence of intact surface layer (ISL) followed by severe depletion in (PO43−) peak in the area corresponding to the body of the lesion. In all examined groups, the mechanical properties of enamel were decreased in lesion area and found to be inversely related to penetration depth of indenter owing to enamel hierarchical structure. By combining the above two techniques, we linked mechanical properties of enamel to its chemical composition and ensured that the two methods are highly sensitive to detect small changes in enamel composition. Further work is required to bring these two excellent tools to clinical application to perceive carious lesions at an early stage of development.
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