F. Millot, Vincent Sarou‐Kanian, J. C. Rifflet, B. Vinet,
The measurement of the surface tension of liquid silicon has a long history with many results but no general agreement between them. Two values at the melting temperature are cited in reviews (749 and 827 mN/m [N. Eustathopoulos, E. Ricci, B. Drevet, Note Technique DEM No. 97/58, CEA, 1997]) but there are few arguments to determine the correct one. In the present study, new data for the surface tension obtained with the analysis of characteristic frequencies of a levitating drop are presented. The ...
Tópico(s): Diamond and Carbon-based Materials Research
2008 - Elsevier BV | Materials Science and Engineering A
Laura Martel, Mathieu Allix, Francis Millot, Vincent Sarou‐Kanian, Emmanuel Véron, Sandra Ory, Dominique Massiot, Michaël Deschamps,
Transparent nanostructured glasses show interesting properties for optical fibers or laser beam applications. Binary calcium silicate glasses are known to undergo phase separation in silica-rich compositions. However, adding up to a few mole percent of alumina seems to inhibit the phase separation. By adjusting the amount of alumina added to demixing calcium silicate glasses, we managed to obtain transparent, but nanostructured, glasses with either silica-rich or calcium aluminosilicate-rich nanodomains ...
Tópico(s): Nuclear materials and radiation effects
2011 - American Chemical Society | The Journal of Physical Chemistry C
Fréderic Roche, Bruno Estour, M. Kadem, L. Millot, Vincent Pichot, David Duverney, Jean‐Michel Gaspoz, Jean Barthélemy,
Myocardial repolarization has been evaluated in patients with anorexia nervosa (AN) with conflicting results. The authors postulated that dynamic alterations in QT interval adaptation could characterize these patients. This study compared QT dynamicity along RR intervals from 24-hour ECG data of patients with and without AN. Twenty-five patients (23 women) fulfilling the Diagnostic and Statistical Manual (DSM IV) criteria for AN were included in the study. All underwent 24-hour ECG Holter recordings, ...
Tópico(s): ECG Monitoring and Analysis
2004 - Wiley | Pacing and Clinical Electrophysiology
Alexandra Aubry, Wladimir Sougakoff, Pamela Bodzongo, Guy Delcroix, Sylvie Armand, G. Millot, Vincent Jarlier, René Courcol, Nadine Lemaître,
Background Tuberculosis (TB) is one of the major public health problems in Congo. However, data concerning Mycobacterium tuberculosis drug resistance are lacking because of the insufficient processing capacity. So, the aim of this study was to investigate for the first time the resistance patterns and the strain lineages of a sample of M. tuberculosis complex (MTBC) isolates collected in the two main cities of Congo. Methods Over a 9-day period, 114 smear-positive sputa isolated from 114 patients ...
Tópico(s): Diagnosis and treatment of tuberculosis
2014 - Public Library of Science | PLoS ONE
R. Dupiol, Katarzyna Krupa, Alessandro Tonello, Marc Fabert, D. Modotto, S. Wabnitz, G. Millot, Vincent Couderc,
We experimentally study the competition between Kerr beam self-cleaning and Raman beam cleanup in a multimode air–silica microstructure optical fiber. Kerr beam self-cleaning of the pump is observed for a certain range of input powers only. Stokes Raman beam generation and cleanup lead to both depletion and degradation of beam quality for the pump. The interplay of modal four-wave mixing and Raman scattering in the infrared domain leads to the generation of a multimode supercontinuum ranging from ...
Tópico(s): Advanced Fiber Laser Technologies
2018 - Optica Publishing Group | Optics Letters
Alioune Niang, Tigran Mansuryan, Katarzyna Krupa, Alessandro Tonello, Marc Fabert, Philippe Leproux, D. Modotto, O. N. Egorova, A.E. Levchenko, Denis S. Lipatov, S. L. Semjonov, G. Millot, Vincent Couderc, S. Wabnitz,
We experimentally demonstrate spatial beam self-cleaning and supercontinuum generation in a tapered Ytterbium-doped multimode optical fiber with parabolic core refractive index and doping profile when 1064 nm pulsed beams propagate from wider (120 micrometers) into smaller (40 micrometers) diameter. In the passive mode, increasing the input beam peak power above 20 kW leads to a bell-shaped output beam profile. In the active configuration, gain from the pump laser diode permits to combine beam self- ...
Tópico(s): Optical Network Technologies
2019 - Optica Publishing Group | Optics Express
Vincent Millot, Adriano Pisante,
We classify nonconstant entire local minimizers of the standard Ginzburg–Landau functional for maps in H^1_{\mathrm{loc}} (ℝ^3;ℝ^3) satisfying a natural energy bound. Up to translations and rotations, such solutions of the Ginzburg–Landau system are given by an explicit solution equivariant under the action of the orthogonal group.
Tópico(s): Advanced Differential Geometry Research
2010 - European Mathematical Society | Journal of the European Mathematical Society
Irene Fonseca, Nicola Fusco, Giovanni Leoni, Vincent Millot,
This work discusses the role of highly anisotropic interfacial energy for problems involving a material void in a linearly elastic solid. Using the calculus of variations it is shown that important qualitative features of the equilibrium shape of the void may be deduced from smoothness and convexity properties of the interfacial energy. Ou discute dans cet article du rôle joué par une énergie d'interface fortement anisotrope pour des problèmes faisant intervenir un vide matériel dans un solide linéairement ...
Tópico(s): Mechanical Behavior of Composites
2011 - Elsevier BV | Journal de Mathématiques Pures et Appliquées
Nicola Fusco, Vincent Millot, Massimiliano Morini,
Recently Frank and Seiringer have shown an isoperimetric inequality for nonlocal perimeter functionals arising from Sobolev seminorms of fractional order. This isoperimetric inequality is improved here in a quantitative form.
Tópico(s): Mathematical Inequalities and Applications
2011 - Elsevier BV | Journal of Functional Analysis
We continue the analysis started in [14] on a model describing a two-dimensional rotating Bose–Einstein condensate. This model consists in minimizing under the unit mass constraint, a Gross–Pitaevskii energy defined in ℝ 2 . In this contribution, we estimate the critical rotational speeds Ω d for having exactly d vortices in the bulk of the condensate and we determine their topological charge and their precise location. Our approach relies on asymptotic energy expansion techniques developed by Serfaty [ ...
Tópico(s): Physics of Superconductivity and Magnetism
2006 - World Scientific | Reviews in Mathematical Physics
We investigate a model corresponding to the experiments for a two-dimensional rotating Bose–Einstein condensate. It consists in minimizing a Gross–Pitaevskii functional defined in R2 under the unit mass constraint. We estimate the critical rotational speed Ω1 for vortex existence in the bulk of the condensate and we give some fundamental energy estimates for velocities close to Ω1.
Tópico(s): Quantum, superfluid, helium dynamics
2005 - Elsevier BV | Journal of Functional Analysis
Tópico(s): Differential Equations and Numerical Methods
2014 - Springer Science+Business Media | Archive for Rational Mechanics and Analysis
Jean‐François Babadjian, Vincent Millot,
Motivated by models of fracture mechanics, this paper is devoted to the analysis of a unilateral gradient flow of the Ambrosio–Tortorelli functional, where unilaterality comes from an irreversibility constraint on the fracture density. Solutions of such evolution are constructed by means of an implicit Euler scheme. An asymptotic analysis in the Mumford–Shah regime is then carried out. It shows the convergence towards a generalized heat equation outside a time increasing crack set. In the spirit ...
Tópico(s): Numerical methods in engineering
2013 - Elsevier BV | Annales de l Institut Henri Poincaré C Analyse Non Linéaire
Vincent Millot, Yannick Sire, Kelei Wang,
This article is mainly devoted to the asymptotic analysis of a fractional version of the (elliptic) Allen–Cahn equation in a bounded domain $${\Omega \subseteq \mathbb{R}^{n}}$$ , with or without a source term in the right hand side of the equation (commonly called chemical potential). In contrast to the usual Allen–Cahn equation, the Laplace operator is here replaced by the fractional Laplacian $${(-\Delta)^s}$$ with $${s \in (0,1/2)}$$ , as defined in Fourier space. In the singular limit $${\varepsilon \to 0}$$ , we show that ...
Tópico(s): Differential Equations and Numerical Methods
2018 - Springer Science+Business Media | Archive for Rational Mechanics and Analysis
Katarzyna Krupa, R. Fona, Alessandro Tonello, Alexis Labruyère, Badr Mohamed Ibrahim Shalaby, S. Wabnitz, Fabio Baronio, Alejandro B. Aceves, G. Millot, Vincent Couderc,
Abstract We experimentally demonstrate the spatial self-cleaning of a highly multimode optical beam, in the process of second-harmonic generation in a quadratic nonlinear potassium titanyl phosphate crystal. As the beam energy grows larger, the output beam from the crystal evolves from a highly speckled intensity pattern into a single, bell-shaped spot, sitting on a low energy background. We demonstrate that quadratic beam cleanup is accompanied by significant self-focusing of the fundamental beam, ...
Tópico(s): Laser-Matter Interactions and Applications
2020 - Nature Portfolio | Scientific Reports
Catherine Guillou, Nicolas Millot, Vincent Reboul, Claude Thal,
Tópico(s): Carbon dioxide utilization in catalysis
1996 - Elsevier BV | Tetrahedron Letters
Federico Luigi Dipasquale, Vincent Millot, Adriano Pisante,
We study global minimizers of a continuum Landau-De Gennes energy functional for nematic liquid crystals, in three-dimensional domains. Assuming smooth and uniaxial (e.g. homeotropic) boundary conditions and a corresponding physically relevant norm constraint (Lyuksyutov constraint) in the interior, we prove full regularity up to the boundary for the minimizers. As a consequence, in a relevant range (which we call the Lyuksyutov regime) of parameters of the model we show that even without the norm ...
Tópico(s): Nonlinear Waves and Solitons
2020 - Springer Science+Business Media | Archive for Rational Mechanics and Analysis
Michel Manfait, Hamid Morjani, Jean‐Marc Millot, Vincent Debal, Jean‐François Angiboust, Igor Nabiev,
Optical microspectroscopic techniques - both powerful and nondestructive - are particularly suited to the study within a single living cell of molecular interactions between drugs (anticancer agents or xenobiotics) and their pharmacological targets. These techniques include vibrational spectroscopy : Raman spectroscopy (conventional resonance SERS) and Fourier transform infrared microspectroscopy together with fluorescence microspectroscopy. Applications are given Ci) in the subcompartmental quantitative ...
Tópico(s): Spectroscopy and Chemometric Analyses
1991 - SPIE | Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Jean‐François Babadjian, Vincent Millot,
Homogenization of integral functionals is studied under the constraint that admissible maps have to take their values into a given smooth manifold. The notion of tangential homogenization is defined by analogy with the tangential quasiconvexity introduced by Dacorogna et al. [Calc. Var. Part. Diff. Eq. 9 (1999) 185–206]. For energies with superlinear or linear growth, a Γ-convergence result is established in Sobolev spaces, the homogenization problem in the space of functions of bounded variation ...
Tópico(s): Composite Material Mechanics
2009 - EDP Sciences | ESAIM Control Optimisation and Calculus of Variations
R. Guenard, Katarzyna Krupa, R. Dupiol, Marc Fabert, A. Bendahmane, Vincent Kermène, Agnès Desfarges‐Berthelemot, Jean‐Louis Auguste, Alessandro Tonello, Alain Barthélémy, G. Millot, S. Wabnitz, Vincent Couderc,
We experimentally demonstrate that Kerr spatial self-cleaning of a pulsed beam can be obtained in an amplifying multimode optical fiber. An input peak power of 500 W only was sufficient to produce a quasi-single-mode emission from the double-clad ytterbium doped multimode fiber (YMMF) with non-parabolic refractive index profile. We compare the self-cleaning behavior observed in the same fiber with loss and with gain. Laser gain introduces new opportunities to achieve spatial self-cleaning of light ...
Tópico(s): Photonic Crystal and Fiber Optics
2017 - Optica Publishing Group | Optics Express
R. Guenard, Katarzyna Krupa, R. Dupiol, Marc Fabert, A. Bendahmane, Vincent Kermène, Agnès Desfarges‐Berthelemot, Jean‐Louis Auguste, Alessandro Tonello, Alain Barthélémy, G. Millot, S. Wabnitz, Vincent Couderc,
We study a coupled cavity laser configuration where a passively Q-switched Nd:YAG microchip laser is combined with an extended cavity, including a doped multimode fiber. For appropriate coupling levels with the extended cavity, we observed that beam self-cleaning was induced in the multimode fiber thanks to nonlinear modal coupling, leading to a quasi-single mode laser output. In the regime of beam self-cleaning, laser pulse duration was reduced from 525 to 225 ps. We also observed a Q-switched ...
Tópico(s): Optical Network Technologies
2017 - Optica Publishing Group | Optics Express
Florence Brossier, Christophe Sola, G. Millot, Vincent Jarlier, Nicolas Véziris, Wladimir Sougakoff,
Fifty-two multidrug-resistant isolates of Mycobacterium tuberculosis representative of the currently predominant lineages in France were analyzed using repetitive-sequence-based PCR (rep-PCR) DiversiLab (DL), spoligotyping, 24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat typing (MIRU-VNTR), and restriction fragment length polymorphism of IS6110 (IS6110-RFLP). DL, as opposed to MIRU-VNTR and IS6110-RFLP analysis, did not allow discrimination among half of the isolates, ...
Tópico(s): Infectious Diseases and Tuberculosis
2014 - American Society for Microbiology | Journal of Clinical Microbiology
Marc Fabert, Maria Săpânţan, Katarzyna Krupa, Alessandro Tonello, Yann Leventoux, Sébastien Février, Tigran Mansuryan, Alioune Niang, Benjamin Wetzel, G. Millot, S. Wabnitz, Vincent Couderc,
A low intensity light beam emerges from a graded-index, highly multimode optical fibre with a speckled shape, while at higher intensity the Kerr nonlinearity may induce a spontaneous spatial self-cleaning of the beam. Here, we reveal that we can generate two self-cleaned beams with a mutual coherence large enough to produce a clear stable fringe pattern at the output of a nonlinear interferometer. The two beams are pumped by the same input laser, yet are self-cleaned into independent multimode fibres. ...
Tópico(s): Optical Network Technologies
2020 - Nature Portfolio | Scientific Reports
Gaël A. Millot, Adeline Berger, Vincent Lejour, Jean-Baptiste Boulé, Claude Bobo, Christophe Cullin, Judith Lopes, Dominique Stoppa‐Lyonnet, Alain Nicolas,
A large number of missense mutations have been identified within the tumor suppressor gene BRCA1. Most of them, called "variants of unknown significance" (VUS), cannot be classified as pathogenic or neutral by genetic methods, which complicates their cancer risk assessment. Functional assays have been developed to circumvent this uncertainty. They aim to determine how VUS impact the BRCA1 protein structure or function, thereby giving an indication of their potential to cause cancer. So far, three ...
Tópico(s): DNA Repair Mechanisms
2011 - Wiley | Human Mutation
Katarzyna Krupa, Alessandro Tonello, Badr Mohamed Ibrahim Shalaby, Marc Fabert, Alain Barthélémy, G. Millot, S. Wabnitz, Vincent Couderc,
The Kerr effect in graded-index multimode fibres drives a spatial beam self-cleaning phenomenon that withstands fibre bending and does not necessitate dissipative processes such as stimulated scattering. Multimode optical fibres are enjoying renewed attention, boosted by the urgent need to overcome the current capacity crunch of single-mode fibre (SMF) systems and by recent advances in multimode complex nonlinear optics1,2,3,4,5,6,7,8,9,10,11,12,13. In this work, we demonstrate that standard multimode ...
Tópico(s): Optical Network Technologies
2017 - Nature Portfolio | Nature Photonics
Etienne Deliancourt, Marc Fabert, Alessandro Tonello, Katarzyna Krupa, Agnès Desfarges‐Berthelemot, Vincent Kermène, G. Millot, Alain Barthélémy, S. Wabnitz, Vincent Couderc,
come from teaching and research institutions in France or abroad, or from public or private research centers.L'archive ouverte pluridisciplinaire
Tópico(s): Laser-Matter Interactions and Applications
2019 - Optica Publishing Group | OSA Continuum
Etienne Deliancourt, Marc Fabert, Alessandro Tonello, Katarzyna Krupa, Agnès Desfarges‐Berthelemot, Vincent Kermène, G. Millot, Alain Barthélémy, S. Wabnitz, Vincent Couderc,
We report experimental results, showing that the Kerr beam self-cleaning of many low-order modes in a graded-index multimode fiber can be controlled thanks to optimized wavefront shaping of the coherent excitation beam. Adaptive profiling of the transverse input phase was utilized for channeling the launched power towards a specific low-order fiber mode, by exploiting nonlinear coupling among all guided modes. Experiments were carried out with 7 ps pulses at 1064 nm injected in a five meters long ...
Tópico(s): Photonic Crystal and Fiber Optics
2019 - Optica Publishing Group | Optics Express
Yann Leventoux, Alexandre Parriaux, Oleg Sidelnikov, G. Granger, Mathieu Jossent, Laure Lavoute, Dmitry Gaponov, Marc Fabert, Alessandro Tonello, Katarzyna Krupa, Agnès Desfarges‐Berthelemot, Vincent Kermène, G. Millot, Sébastien Février, S. Wabnitz, Vincent Couderc,
We experimentally demonstrate that spatial beam self-cleaning can be highly efficient when obtained with a few-mode excitation in graded-index multimode optical fibers. By using 160 ps long, highly chirped (6 nm bandwidth at -3dB) optical pulses at 1562 nm, we demonstrate a one-decade reduction of the power threshold for spatial beam self-cleaning, with respect to previous experiments using pulses with laser wavelengths at 1030-1064 nm. Self-cleaned beams remain spatio-temporally stable for more than ...
Tópico(s): Optical Network Technologies
2020 - Optica Publishing Group | Optics Express
F. Millot, J. C. Rifflet, Vincent Sarou‐Kanian, Guillaume Wille,
Tópico(s): High-pressure geophysics and materials
2002 - Springer Science+Business Media | International Journal of Thermophysics
Michaël Goldman, Benoît Merlet, Vincent Millot,
Nous étudions un modèle variationnel en deux dimensions qui combine les caractéristiques des fonctionnelles de Ginzburg–Landau et de Mumford–Shah. Comme dans la théorie classique de Ginzburg–Landau (et dans le régime de faible énergie) un nombre prescrit de vortex apparaît ; le modèle autorise aussi la formation de lignes de discontinuité dont l’énergie pénalise la longueur. Le phénomène nouveau est que les vortex ont un degé fractionnaire 1/m prescrit et qu’ils doivent être connectés par les lignes ...
Tópico(s): Caveolin-1 and cellular processes
2021 - Association of the Annals of the Fourier Institute | Annales de l’institut Fourier