Publications

Affichage de 871 à 880 sur 1005

ART

Exponential stability of the wave equation on a star shaped network with indefinite sign damping

Farah Abdallah, Denis Mercier, Serge Nicaise

In this paper, we study the stability of the wave equation on a star shaped network in the presence of indefinite sign damping terms. Extending the results of Freitas and Zuazua in [13], we search for sufficient conditions on the damping coefficients for which the problem becomes exponentially…

Palest. J. Math, 2013, 2 (2), pp.113-143. ⟨hal-03134884⟩

ART

A locking-free discontinuous Galerkin method for linear elasticity in locally nearly incompressible heterogeneous media

Daniele Antonio Di Pietro, Serge Nicaise

In this work we consider the problem of numerical locking in composite materials featuring quasi-incompressible and compressible sections. More specifically, we start by extending a classical regularity estimate for the $H^1$-norm of the divergence of the displacement field to the heterogeneous…

Applied Numerical Mathematics: an IMACS journal, 2012, 63, pp.105-116. ⟨10.1016/j.apnum.2012.09.009⟩. ⟨hal-00685020⟩

ART

Crystal structures of Boro-AFm and sBoro-AFt phases

Jean-Baptiste Champenois, Adel Mesbah, Céline Cau Dit Coumes, Guillaume Renaudin, Fabrice Leroux, Cyrille Albert-Mercier, Bertrand Revel, Denis Damidot

Crystal structures of boron-containing AFm (B-AFm) and AFt (B-AFt) phases have been solved ab-initio and refined from X-ray powder diffraction. 11B NMR and Raman spectroscopies confirm the boron local environment in both compounds: three-fold coordinated in B-AFm corresponding to HBO3 2− species,…

Cement and Concrete Research, 2012, 42 (10), pp.1362-1370. ⟨10.1016/j.cemconres.2012.06.003⟩. ⟨hal-02043826⟩

ART

Takacs-Fiksel method for stationary marked Gibbs point processes

Jean-François Coeurjolly, David Dereudre, Rémy Drouilhet, Frédéric Lavancier

This paper studies a method to estimate the parameters governing the distribution of a stationary marked Gibbs point process. This procedure, known as the Takacs-Fiksel method, is based on the estimation of the left and right hand sides of the Georgii-Nguyen-Zessin formula and leads to a family of…

Scandinavian Journal of Statistics, 2012, 39 (3), pp.416-443. ⟨10.1111/j.1467-9469.2011.00738.x⟩. ⟨hal-00502004v2⟩

ART

Existence of Gibbsian point processes with geometry-dependent interactions

David Dereudre, Rémy Drouilhet, Hans Otto Georgii

We establish the existence of stationary Gibbsian point processes for interactions that act on hyperedges between the points. For example, such interactions can depend on Delaunay edges or triangles, cliques of Voronoi cells or clusters of k-nearest neighbors. The classical case of pair…

Probability Theory and Related Fields, 2012, 153 (3-4), pp.643-670. ⟨10.1007/s00440-011-0356-5⟩. ⟨hal-00850422⟩

ART

Stability of tetragonal 〈001〉 oriented PZN-12PT single crystals

S. Touhtouh, A. Hajjaji, Y. Boughaleb, K. Benkhouja, A. Arbaoui, Mohamed Rguiti, D. Guyomar

The present paper reports on the synthesis and electromechanical characterization of tetragonal (1 − x)Pb(Zn1/3–Nb2/3)O3–xPbTiO3 (x = 12) single crystals as a function of various external disturbances. Tetragonal PZN-12PT single crystals were grown using the flux method. The set of piezoelectric…

Optical Materials, 2012, 34 (10), pp.1625-1629. ⟨10.1016/j.optmat.2012.04.002⟩. ⟨hal-04281119⟩

ART

Biomimetic evaluation of β tricalcium phosphate prepared by hot isostatic pressing

Mihaela Mateescu, Emmanuelle Rguitti, Arnaud Ponche, Michel Descamps, Karine Anselme

Two types of completely densified β-TCP tablets were synthesized from a stoichiometric β-TCP powder. The first ones (TCP) were conventionally sintered, while the second ones (TCP-T) were sintered and treated by hot isostatic process (HIP). The HIP produced completely densified materials with…

Biomatter, 2012, 2 (3), pp.103-113. ⟨10.4161/biom.21377⟩. ⟨hal-02584462⟩

ART

Morphotropic phase boundary in the BNT–BT–BKT system

Jean-François Trelcat, Christian Courtois, Mohamed Rguiti, Anne Leriche, Paul-Henri Duvigneaud, Tiriana Segato

Lead-free x Bi0.5Na0.5TiO3–y BaTiO3–z Bi0.5K0.5TiO3 piezoelectric ceramics were synthesized by a conventional solid state reaction method. The microstructure, ferroelectric and piezoelectric properties of the ceramics were investigated. Structure measurements by X-ray diffraction with Rietveld…

Ceramics International, 2012, 38 (4), pp.2823-2827. ⟨10.1016/j.ceramint.2011.11.053⟩. ⟨hal-04281117⟩

ART

Stabilization of non-homogeneous elastic materials with voids

Serge Nicaise, Julie Valein

We study the asymptotic behavior of the solution of the non-homogeneous elastic system with voids and a thermal effect. We first prove the well-posedness of this system under some realistic assumptions on the coefficients. Since this system suffers of exponential stability (as shown in dimension 1…

Journal of Mathematical Analysis and Applications, 2012, 387 (2), pp.1061-1087. ⟨10.1016/j.jmaa.2011.10.018⟩. ⟨hal-00644065⟩

THESE

Elaboration et caractérisations de bioverres Si-Ca-Na-O et Si-Ca-Na-O-F dopés à l'azote, No title in english

Ahmed Bachar

L’étude de l’incorporation de l’azote dans des bioverres du système SiO2-Na2O-CaO, a été abordée selon une approche globale de la synthèse des bioverres oxynitrurés et oxyfluoronitrurés jusqu’à leurs caractérisations physico-chimiques, mécaniques et biologiques. Les protocoles de synthèse de ces…, This work presents the study of nitrogen addition in bioglasses of the system SiO2-Na2O-CaO. The purpose is to determine the effects of nitrogen addition on the physical and mechanical properties and the structure of oxynitride bioglasses based on the system Na2O-CaO-SiO2-Si3N4.In first time, the…

Matériaux. Université de Valenciennes et du Hainaut-Cambresis; Université Mohammed V-Agdal (Rabat, Maroc ; 1993-2014), 2012. Français. ⟨NNT : 2012VALE0008⟩. ⟨tel-00789198⟩