Matériau support des panneaux muraux fontaines en zellige marocain carreaux céramiques

Le domaine de la recherche dans les matériaux composites est encore nouveau dans les universités et les centres de recherche au Maroc. Les applications des matériaux composites dans les différentes branches industrielles couvrent divers secteur d’activités. L'objectif principal de ce travail est la valorisation des tables d'artisanat traditionnel, des panneaux muraux, fontaines en zellige marocain et carreaux céramiques en les rendant plus attrayants, plus légers et plus écologiques par l’élaboration des matériaux composites sur les critères «3E»: économique (sans énergie), écologique (procédé propre) et environnemental (recyclage et valorisation des déchets: la poudre de marbre, la pierre ponce usagée issue des industries de délavage...

Reactions de rearrangement de squelette des hydrocarbures sur catalyseurs Pt-Co/Al2O3 : etude des mecanismes par tracage au carbone 13; caracterisation physique des catalyseurs

SIGLECNRS T 56496 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Modeling effective elastic and thermal conductivity of composite materials reinforced with plastic waste: Analytical and numerical approaches

International audienceThe properties of materials used in building are enhanced by adding nanoparticles for improve energy efficiency. The objective of this study is to offer both numerical and analytical modeling methods of the thermal conductivity and mechanical property of composite materials. Various mineral charges were employed to reinforce the organic matrices of saturated polyester resin (UPR) with calcium carbonate (CaCo3) and expanded perlite particles. The study employs the finite-element software COMSOL to conduct a numerical investigation of thermal transport in an elementary cell. The purpose is to ascertain the thermal conductivity of composites and examine the impact of contact resistance and the volume fraction of nanoparticles on the effective thermal conductivity. The results indicate that the numerical model proposed is consistent with the Hashin-Shtrikman analytical model and experimental measurements. In another hand, the mechanical property is computed based on Mori-tanaka analytical model of homogenization and finite element method by Digimat-MF/FE, which gives enhanced elastic behavior of composite in function of volume fraction of nanoparticles, with high Young modulus and low Poisson ratio. The results indicate the performance of nanoparticles in improving thermomechanical behavior of building materials, and also in other applications

Exploring the Thermophysical Properties of the Thermal Conductivity of Pigmented Polymer Matrix Composites with Barium Titanate: A Comparative Numerical and Experimental Study

This research paper focuses on investigating the thermal conductivity behavior of polymer matrix composite materials, specifically those composed of PSU and BaTiO3, both experimentally and numerically. The thermal conductivity of composites has been studied using a variety of theoretical and semi-empirical methods. However, in cases where the filler concentration is minimal, these models provide a superior estimate. To numerically resolve the thermal heat transfer for an elementary cell, the finite element method is employed in this study. The impact of contact resistance, barium titanate percentage, and quenching temperature on the composite’s effective thermal conductivity and dynamic behavior is given consideration. The results demonstrate that the suggested numerical model is in good agreement with experimental measurements as well as Hatta–Taya and Hashin–Shtrikman’s analytical models. The results provide significant insight into the thermal conductivity behavior of composites, which can inform the development of more effective thermal management solutions for composite materials. Effective thermal management is critical for the successful application of polymer matrix composite materials in various engineering applications. Thermal conductivity is a key factor in thermal management and is influenced by factors such as the concentration of filler particles, their shape, size, and distribution, and the matrix material’s properties

Kinetics of reactions catalyzed by metals: role of surface hydrocarbon residues in conversion of alkanes on Pt

It is shown that the total carbon coverage as measured by AES after reaction of alkanes on platinum surfaces can be broken down into three types of carbon atoms: (i) a small carbon coverage of about 4%, present on the metal surface previous to any reaction, thus independent of the reaction studied and attributed to impurities; (ii) carbon atoms existing in the form of chemisorbed radical hydrocarbon active intermediates in the reaction under the catalytic working conditions, and thus reversibly adsorbed under these conditions. This coverage is quite instantaneously attained; (iii) carbon atoms in the form of highly dehydrogenated and irreversibly adsorbed species, the coverage of which increases slowly but continuously with time. The formation of this type of carbon is attributed to a side reaction. It is clearly shown that these carbon atoms act as a poison for the studied reactions and not as a cocatalyst, as previously proposed by Somorjai. This difference in concept is associated with a difference in point of view of the reaction mechanism. Special attention is paid to experimental procedures, some of which induce an apparent irreversibility in the chemisorbed carbonaceous residues. © 1990.SCOPUS: ar.jinfo:eu-repo/semantics/publishe