Coarsening in inhomogeneous systems

This article is a brief review of coarsening phenomena occurring in systems where quenched features—such as random field, varying coupling constants or lattice vacancies—spoil homogeneity. We discuss the current understanding of the problem in ferromagnetic systems with a non-conserved scalar order parameter by focusing primarily on the form of the growth law of the ordered domains and on the scaling properties.     

Modélisation du transport réactif en milieu poreux : schéma itératif associé à une combinaison d'éléments finis discontinus et mixtes-hybridesModelling reactive transport in porous media: iterative scheme and combination of discontinuous and mixed-hybrid finite elements

The sequential iterative approach (SIA) scheme is the most efficient method for modelling reactive transport in porous media with the operator-splitting approach. A combination of finite discontinuous and finite mixed-hybrid elements is a powerful method for solving solute transport in porous media, but the use of this method for SIA scheme induces numerical difficulties. In this paper, a new method is developed to solve reactive transport by using both the SIA scheme and a combination of finite discontinuous and finite mixed elements. The proposed method is tested by modelling a column experiment. To cite this article: J. Carrayrou et al., C. R. Mecanique 331 (2003).     

Sorption Technique of Separation of Thallium-201 from Proton-Irradiated Thallium

A sorption technique is developed for radiochemical separation of thallium-201 from proton-irradiated targets of metallic thallium. The technique consists in separation of ²⁰¹Pb with the PbSO₄ precipitate followed by separation of ²⁰¹Pb and ²⁰¹Tl in the column with ammonium 12-molybdophosphate fixed in the matrix of porous Teflon (AMP-sorbent). The chemical yield of radiothalium is 98%, the duration of chemical procedures is 2.5 … 3 hours.     

On the Navier–Stokes equations simulation of the head-on collision between two surface solitary waves

The scope of this Note is to show the results obtained for simulating the two-dimensional head-on collision of two solitary waves by solving the Navier–Stokes equations in air and water. The work is dedicated to the numerical investigation of the hydrodynamics associated to this highly nonlinear flow configuration, the first numerical results being analyzed. The original numerical model is proved to be efficient and accurate in predicting the main features described in experiments found in the literature. This Note also outlines the interest of this configuration to be considered as a test-case for numerical models dedicated to computational fluid mechanics. To cite this article: P. Lubin et al., C. R. Mecanique 333 (2005).     

Synthesis of Novel Core Cross‐Linked Star‐Based Polyrotaxane End‐Capped via “CuAAC” Click Chemistry

The first example of core cross‐linked star (CCS) polyrotaxane was prepared using the poly(ϵ‐caprolactone) (PCL) CCS three‐dimensional (3D) scaffold. The 3D CCS polymer was firstly prepared through the “arm‐first” approach. Then, the “arms” of the resultant PCL CCS polymer were threaded with α‐cyclodextrins (α‐CDs). The threaded α‐CDs were permanently locked by the “click” reaction of terminal alkyne functionalities of the star polymers with the azide‐functionalized end caps to afford the CCS polyrotaxanes. All analytical results confirm the formation of the CCS polyrotaxanes and reveal their characteristics, including fluorescence under UV, a channel‐type crystalline structure, a two‐step thermal decomposition, and a unique core‐shell structure in great contrast to the polymer precursors.