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Grenoble, France

Stendhal University, Grenoble III is a French university located in the outskirts of Grenoble offering courses in foreign languages and cultures, ancient and modern literature, language and communication science. Having traditionally focused on training educators, it has more recently become known for preparing students for careers in journalism, communication and culture.Each year, the CUEF educates over 3,000 foreign students through various exchange programs in fields covering the entire spectrum of French studies.The current president is Lise Dumasy. Wikipedia.

Xue K.-H.,Stendhal University | Blaise P.,CEA Grenoble | Fonseca L.R.C.,University of Campinas | Nishi Y.,Stanford University
Physical Review Letters | Year: 2013

Tetragonal semimetallic phases are predicted for Hf2O 3 and Zr2O3 using density functional theory. The structures belong to space group P4̄m2 and are more stable than their corundum counterparts. Many body corrections at first order confirm their semimetallic character. The carrier concentrations are very similar for both materials, and are estimated as 1.8×1021 cm-3 for both electrons and holes, allowing for electric conduction. This could serve as a basic explanation for the low resistance state of hafnia-based resistive random access memory. © 2013 American Physical Society. Source

Ghibaudo G.,Stendhal University
Solid-State Electronics | Year: 2012

The variability performance of JAM devices is studied owing to an analytical formula for V t variance and to 2D numerical simulation doping sensitivity analysis. Both approaches clearly indicate that JAM devices exhibit 2-5 times larger V t and drain current variability than in inversion mode Trigates. This suggests that the optimization of JAM transistors should carefully take into account this aspect in their technological design. © 2012 Elsevier Ltd. All rights reserved. Source

Fries P.H.,Stendhal University
Journal of Chemical Physics | Year: 2010

We present a two-particle Monte Carlo method for computing the outer-sphere (OS) dipolar time correlation function (DTCF) of the relative position of a nuclear spin I on a diamagnetic molecule MI with respect to a nuclear or electronic spin S on a molecule MS when both molecules are anisotropic and undergo translational and rotational diffusion. As a first application, we question the validity of the appealing interspin procedure [L. P. Hwang, Mol. Phys. 51, 1235 (1984); A. Borel, Chem. Eur. J. 7, 600 (2001)] based on the solutions of a Smoluchowski diffusion equation, which conserve the interspin radial distribution function in the course of time. We show that the true random spatial motion of the interspin vector obtained by simulation can be very different from that given by the Smoluchowski solutions and lead to notable retardation of the time decay of the OS-DTCF. Then, we explore the influence of the solvation properties of MS on the decay rate of the DTCF. When MS is significantly larger than MI, its rotation accelerates the decay only weakly, even if MI follows M S in its Brownian tumbling. By contrast, viscous solvation layers in OS pockets of MS can yield an important local slowdown of the relative translational diffusion of MI, leading to a decay retardation of the DTCF, which adds to that due to the shape anisotropy of MS. When MS is a Gd3+ -based contrast agent, this retardation leads to a notable increase of the OS contribution to relaxivity even at rather high imaging field. © 2010 American Institute of Physics. Source

Fries P.H.,Stendhal University | Belorizky E.,Joseph Fourier University
Journal of Chemical Physics | Year: 2010

We present a theoretical model for calculating the relaxivity of the water protons due to Gd3+ complexes trapped inside nanovesicles, which are permeable to water. The formalism is applied to the characterization of apoferritin systems [S. Aime, Angew. Chem., Int. Ed. 41, 1017 (2002); O. Vasalatiy, Contrast Media Mol. Imaging 1, 10 (2006)]. The very high relaxivity due to these systems is attributed to an increase of the local viscosity of the aqueous solution inside the vesicles and to an outer-sphere mechanism which largely dominates the inner-sphere contribution. We discuss how to tailor the dynamic parameters of the trapped complexes in order to optimize the relaxivity. More generally, the potential of relaxivity studies for investigating the local dynamics and residence time of exchangeable molecules in nanovesicles is pointed out. © 2010 American Institute of Physics. Source

Fries P.H.,Stendhal University
European Journal of Inorganic Chemistry | Year: 2012

In a molecular frame rigidly bound to the contrast agent, the instantaneous zero-field splitting (ZFS) Hamiltonian acting on the Gd 3+ electronic spin, S, has a constant mean value, named static ZFS (Hamiltonian). Expressed in the laboratory frame, the static ZFS has a random variation with time, which stems from the Brownian rotation of the complex and can be the source of a fast electronic spin relaxation that significantly quenches the relaxivity at low field. Except in a few cases, the static ZFS is too large and the Brownian rotation is too slow for the electronic relaxation to be described by Redfield analytical equations. Here, we present a formalism for simulating the quantum time correlation functions (TCFs) of the electronic spin operators, which properly account for relaxivity quenching by electronic relaxation. Though the formalism can be used at all field values, the interpretation of the high-field relaxivity with the help of simple justified analytical equations is recommended. The simulation procedure is illustrated by the case study of a model of the complex Gddtpa {[Gd 3+(dtpa)(H 2O)] 2- (dtpa 5- = diethylenetriamine pentaacetate)}. The numerical implementation of the simulation at several levels of parallel computing is examined. Simulated time correlation functions of the fluctuating intramolecular local dipolar field created by Gd 3+ in a Gddtpa-like complex giving rise to inner sphere relaxivity at 0 and 1.25 T. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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