Search results for "GLASS"
showing 10 items of 1153 documents
Effect of thermocycling with or without 1 year of water storage on retentive strengths of luting cements for zirconia crowns
2015
Abstract Statement of problem Bond stability between zirconia crowns and luting cement and between cement and dentin is a main concern; however, only limited evidence is available as to its longevity. Purpose The purpose of this in vitro study was to measure the retentive strengths of 7 self-adhesive cements (RelyX Unicem Aplicap, RelyX Unicem Clicker, RelyX Unicem 2 Automix, iCEM, Maxcem Elite, Bifix SE, SpeedCem), 2 adhesive cements with self-etch primers (Panavia 21, SEcure), 1 glass ionomer cement (Ketac Cem), 1 resin-modified glass ionomer cement (Meron Plus), and 1 zinc phosphate cement for luting zirconia crowns (LAVA) to extracted teeth after thermocycling with or without 1 year of …
Determination of hydrogen peroxide using glassy carbon and graphite/polyester composite electrodes modified by vanadium-doped zirconias
2002
Abstract Synthetic monoclinic and tetragonal vanadium-doped zirconias (VZrO2) with vanadium loading ranging from 0.5 to 15 mol% are used to modify glassy carbon and graphite/polyester composite electrodes able to detect oxygen and hydrogen peroxide in neutral aqueous media. Electrodes modified by monoclinic VZrO2 decrease the overpotential for the reduction of oxygen and hydrogen peroxide in neutral and alkaline media and enhance their reduction currents with respect to unmodified carbon electrodes. This is associated to seven-coordinated vanadium centers isomorphously substituting zirconium ones in the ZrO2 lattice. The catalytic effect shows site-selectivity, since it is almost entirely a…
Influence de l'orientation des fibres sur un essai Arcan = Influence of fiber orientation on Arcan test data
2009
National audience; Ce papier présente les résultats d'une étude expérimentale portant sur le comportement d'éprouvettes ‘papillon' en verre/époxy, soumises à des chargements de cisaillement pur et de traction-cisaillement combinés, au moyen d'un dispositif Arcan. Des éprouvettes dont les fibres sont orientées parallèlement à la direction des entailles et d'autres pour lesquelles les fibres sont perpendiculaires à cette direction, respectivement désignées Mat31 et Mat32, ont été testées pour différents angles de sollicitation, dans une plage comprise entre 0° et 90°. Le mode de rupture observé pour les éprouvettes Mat31 est répétitif, alors qu'il dépend de la direction de la sollicitation po…
High third and second order non linearities of chalcogenide glasses and fibers for compact infrared non linear devices.
2008
Due to their intrinsic nature, chalcogenide glasses present attractive nonlinearities from third and second order, with values reaching between 10 and 1000 times those of silica. We present a study of their properties and their shaping with the purpose to reach efficient devices in the near-mid infrared.
Study of supercontinuum sources based on tellurite glass optical fibers for mid-infrared absorption spectroscopy applied to gas sensing
2015
This work focuses on the development of mid-infrared supercontinuum light sources and their application for gas detection through absorption spectroscopy. The study of supercontinuum sources is based on nonlinear ultrashort pulse propagation in tellurite glass (80TeO2-10ZnO-10Na2O) and used in three different forms, namely a thin bulk sample, a microstructured suspended-core fiber, and a tapered suspended-core fiber. These technical means adapt themselves to distinct laser sources commercially available, thus optimizing the implementation of ultrawide-band infrared light sources. Experimental observations are compared to corresponding numerical simulations, thus pointing out the different u…
Le cimetière du second Âge du fer de la Tournière à Lailly (Yonne) : nouvelle analyse des fouilles anciennes
2021
International audience; Cette étude présente de manière critique les découvertes qui ont été faites à la fin du xix e siècle et au début du xx e siècle à Lailly La Tournerie (Yonne). Elle propose un classement typologique et chronologique de tous les objets mis au jour par catégorie fonctionnelle, ainsi que la reconstitution, pour la première fois, de plusieurs ensembles clos. Elle a ainsi permis de proposer une évolution de ce cimetière entre le second quart du v e siècle (La Tène A ancienne) et la première décennie du ii e siècle avant J.-C. (La Tène C1). L'analyse des pratiques funéraires a également été abordée à l'aide d'un dépouillement systématique des rares données existantes. Leur …
The Glass Tiles from Saint-Sauveur ( Burgundy, France)
2018
International audience; Eight glass tiles from Saint-Sauveur in Burgundy, which are considered to be of early medieval date, were investigated. These tiles, which are in a good state of preservation, are 10 centimeters square and nearly two centimeters thick. They are made of dark glass with red and white glass inlays. These glass tiles have often been compared with those from the early medieval monastery of Corvey in Germany. However, because they lack an archaeological context, their date is uncertain.PIXE-PIGE and LA-ICP-MS analyses revealed a wood-ash glass composition, close to that of High Lime Low Alkali (HLLA) glass dating from the 14th century and later. The authors’ trace analyses…
Şeffaf cisimlerim 3B taranması
2010
Many practical tasks in industry, such as automatic inspection or robot vision, often require scanning of three-dimensional shapes with non-contact techniques. However, transparent objects, such as those made of glass, still pose difficulties for classical scanning techniques. The reconstruction of surface geometry for transparent objects is complicated by the fact that light is transmitted through, refracted and in some cases reflected by the surface. Current approaches can only deal relatively well with sub-classes of objects. The algorithms are still very specific and not generally applicable. Furthermore, many techniques require considerable acquisition effort and careful calibration. T…
A contribution to the study of staling of white bread: effect of water and hydrocolloid
1996
Abstract Staling of white bread at ambient temperature was studied using differential scanning calorimetry and dynamic mechanical thermal analysis. During storage, sample hydration varied slightly, from 0 to 0.4% per day, depending on packaging conditions. An increase in rigidity was observed, which was attributed both to starch retrogradation and to changes in the organization of the amorphous part of crumb. The glass transition temperature of crumb was not significantly modified by these structural changes. Hydrocolloids did not affect the overall shape of the viscoelastic behavior of crumb in the temperature range from −40°C to 80°C, and had a limited influence on the kinetics of starch …
Un conjunto de materiales arqueológicos del Morrón del Cid (La Iglesuela del Cid, Teruel)
2018
In this paper we present a new iberic and roman archaeological assemblage from Morron del Cid. We pretend add new data for the acknowledgment of this important site.