Search results for "CEM"
showing 10 items of 3487 documents
Évolution de la mobilité des personnes gênées dans leurs déplacements entre 1994 et 2008
2015
International audience
La part des cotisations dans le budget des confédérations syndicales
2012
The paper analyses the budget of the seven French trade union confederations (CGT, CFDT, FO, CFTC, CGC, and USS UNSA). Since 2011, these organizations are obliged to publish their budgets according to the principle of transparency. The main purpose was to give the members' dues the higher weight in the total of the trade union budgets. Each organization has defined its reporting entity in terms of this issue. They did "derive" at the federal level the maximum members' contributions - even when these contributions were not intended to the federal level - and they housed most grants and subsidies in satellites outside their perimeter. Finally, the staffs made available, free of charge, to the…
Numerical vibroacoustic analysis of plates with constrained-layer damping patches
2011
International audience; A numerical vibroacoustic model that can manage multilayered plates locally covered with damping patches is presented. All the layers can have an on-axis orthotropic viscoelastic behavior. Continuity of displacements and transverse shear stresses at each interface is enforced, which permits to write the entire displacement field in function of the displacements of the-common-first layer, leading to a two-dimensional plate model. The problem is then discretized by Rayleigh-Ritz's method using a trigonometric basis that includes both sine and cosine functions in order to treat various boundary conditions. The excitation can be of mechanical kind (concentrated or distri…
Influence of aluminates phases hydration in presence of calcium sulfate on silicates phases hydration : consequences on cements optimum sulfate
2012
The mechanical properties of hydrated cements need to be optimized according to the nature of cement products. Among the factors of optimization, the addition of calcium sulphate intended to regulate the reactivity of tricalcium aluminate (C3A), in quantity and quality in cement is an essential parameter.The advancement of knowledge on the mechanisms of hydration of each cement phase allows a study devoted entirely to the concept of optimum of sulphate. We studied simple system that we complicated and we studied the evolution of hydration, porosity and mechanical properties of cement at different age. The first system studied was the mixture C3S/gypsum, the objective was to determine whethe…
Study of parameters endogeneous and exogeneous to ordinary Portland ciment influencing hydration of its main phase : tricalcium silicate
2012
This work devoted to study various parameters influencing hydration of silicate phase main Ordinary Portland Cement (OPC) was performed at the Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB). This study is part of the project "Crystal Growth Control" initiated by BASF in order to monitor and provide the best as possible the hydration of Ordinary Portland Cement. The dissolution of alite, like the pure C3S one, is fast in pure water. Speed decreases with deviation from equilibrium and the concentration of aluminates ions in solution. There is also an adsorption on the surface of the aluminum which is into the alite and released by dissolution. Germination and growth of C-S-H has bee…
Manufacturing and characterization of Al matrix composites with nano reinforcements via cold spraying
2019
This study aims at developing new routes for manufacturing Al matrix composites (AMCs) strengthened with nano reinforcements by solid-state cold spraying (CS) process. Three different AMCs including CNTs/Al, TiB2/AlSi10Mg and TiB2/7075Al were successfully fabricated by CS of the composite powders prepared using different approaches. The microstructure evolution of as-sprayed composite samples was investigated by means of different characterization methods like X-ray diffraction (XRD), scanning (SEM) and transmission electron microscopy (TEM) and electron backscatter diffraction (SEM/EBSD). The adhesion strength, tribological behaviour, corrosion properties as well as the mechanical performa…
A Robust Multi Stage Technique for Image Binarization of Degraded Historical Documents
2017
International audience; Document image binarization is a central problem in many document analysis systems. Indeed, it represents one of the basic challenges, especially in case of historical documents analysis. In this paper, we propose a novel robust multi stage framework that combines different existing document image thresholding methods for the purpose of getting a better binarization result. CLAHE technique is introduced to significantly enhance contrast in some poor images. The proposed method then uses a hybrid algorithm to partition image into foreground and background. A special procedure is finally applied in order to remove small noise and correct characters morphology. Experime…
Determining the effects of Eugenol on the bond strength of resin-based restorative materials to dentin : a meta-analysis of the literature
2020
Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2076-3417/10/3/1070/htm Este artículo pertenece al número especial " Permanent and long-term biodegradable biomaterials". The aim of this study was to determine whether the residual presence of eugenol in coronal dentin may compromise the bond strength of resin-based restorative materials. A search was performed on MEDLINE/Pubmed, Scopus, and by hand search for relevant papers. No restriction was applied for language and publication date. The studies selected for analysis tested specimens with reduced size (micro-shear bond strength ( SBS) and micro-tensile bond strength ( TBS)) of adhesive systems and resin-bas…