Molecular dynamics simulation of Eu3+ in aqueous solution comparison with experimental luminescence spectra

Using molecular dynamics simulations, we have studied the environment of Eu3+ salts in aqueous solution. In the case of hydration number of 8, the symmetry of the first hydration shell is found to be very close to the D4d. We have therefrom calculated the ligand field parameters according to the point charge model. The luminescence spectra were reconstructed from this set of computed Bkq, and finally compared with experimental spectra

Comparaison de techniques d'absorptions vibro-acoustiques

National audienceThis study presents the design of a test-rig built to caracterize a vibro-acoustical absorber. This experimental system is based on the properties of a short Kundt tube allowing low frequencies studies (below the first natural frequency of the tube). A precise measure method (surdetermined two-microphones method) is proposed in order to obtain the desired acoustical parameters of the absorber. Finally, we propose an energy balance of the obtanied frequency response (excitation frequency and its harmonics).Cette étude propose la conception d'un banc d'essai servant à la caractérisation d'absorbeurs vibro-acoustiques. Ce banc est conç u sur la propriété d'un tube de Kundt court permettant le travail en basses fréquences (en-dessous de la première fréquence de résonance du tube). Une méthode de me-sure fine (méthode à deux microphones surdéterminée) est mise en place afin d'extraire les paramètres acoustiques souhaités de l'absorbeur et in fine proposer un bilan énergétique résultant et sa répartition spectrale (fréquence d'excitation et ses harmoniques)

Magnetic Skyrmions Under Confinement

We present a variational treatment of confined magnetic skyrmions in a minimal micromagnetic model of ultrathin ferromagnetic films with interfacial Dzylashinksii-Moriya interaction (DMI) in competition with the exchange energy, with a possible addition of perpendicular magnetic anisotropy. Under Dirichlet boundary conditions that are motivated by the asymptotic treatment of the stray field energy in the thin film limit we prove existence of topologically non-trivial energy minimizers that concentrate on points in the domain as the DMI strength parameter tends to zero. Furthermore, we derive the leading order non-trivial term in the Gamma\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Gamma$$\end{document}-expansion of the energy in the limit of vanishing DMI strength that allows us to completely characterize the limiting magnetization profiles and interpret them as particle-like states whose radius and position are determined by minimizing a renormalized energy functional. In particular, we show that in our setting the skyrmions are strongly repelled from the domain boundaries, which imparts them with stability that is highly desirable for applications. We provide explicit calculations of the renormalized energy for a number of basic domain geometries

Query Analyzer and Manager for Complex Event Processing as a Service

Complex Event Processing (CEP) is a set of tools and techniques that can be used to obtain insights from high-volume, high-velocity continuous streams of events. CEP-based systems have been adopted in many situations that require prompt establishment of system diagnostics and execution of reaction plans, such as in monitoring of complex systems. This article describes the Query Analyzer and Manager (QAM) module, a first effort toward the development of a CEP as a Service (CEPaaS) system. This module is responsible for analyzing user-defined CEP queries and for managing their execution in distributed cloud-based environments. Using a language-agnostic internal query representation, QAM has a modular design that enables its adoption by virtually any CEP system

Molecular dynamics simulation of silver nanoparticles in a europium doped sodosilicate glass

Molecular dynamics simulation is applied to an europium doped sodosilicate glass containing silver [(Na–Ag)2O–SiO2–Eu2O3]. The silver is implanted in substitution of Na, simulating an ionic exchange. For ionic interactions a modified Born–Mayer–Huggins potential was employed. For the Ag–Ag interaction, a Lennard-Jones (LJ) potential is applied, while for the Eu–Ag interaction, a modified LJ potential is introduced. The particle size increases with the annealing treatment and follows a lognormal law. After 75 ps the average particle size reaches 5.8 atoms (4.8 for Ag and 1.0 for Eu), and it is found that the europium is preferentially situated on these nanoclusters

The complexity of tangent words

In a previous paper, we described the set of words that appear in the coding of smooth (resp. analytic) curves at arbitrary small scale. The aim of this paper is to compute the complexity of those languages.Comment: In Proceedings WORDS 2011, arXiv:1108.341