Séminaires

Le séminaire hebdomadaire du laboratoire PMMH a lieu tous les vendredis à 11h, au premier étage Barre Cassan, campus Jussieu (plan).

Mathias Fink (Institut Langevin, ESPCI ParisTech)

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Archives des anciens séminaires  (476)

• 2023

  • Séminaire PMMH - Angela Limare (IPGP)
    Vendredi 24 mars de 11h00 à 12h00 - Salle réunion PMMH 1
    The Earth's mantle in a microwave oven : thermal convection driven by a heterogeneous distribution of heat sources
    Past laboratory experiments of thermo chemical convection have dealt with systems involving fluids with different intrinsic densities and viscosities in a Rayleigh-Bénard setup. Although these experiments have greatly improved our understanding of the Earth's mantle dynamics, they neglect a fundamental component of (...)
  • Séminaire PMMH Jean Cappello (ULB, Bruxelles)
    Vendredi 17 mars de 11h00 à 12h00 - Salle réunion PMMH 1
    Bioinspired shape shifting of liquid-infused ribbed sheets
    At small scales, capillary forces can deform flexible structures. The aggregation of wet hair into bundles is a daily example. With the miniaturization of technologies, these capillary forces have become important in engineering since they can lead to the catastrophic collapse of structures obtained by lithography (...)
  • Séminaire PMMH Jean Cappello (ULB, Bruxelles)
    Vendredi 17 mars de 11h00 à 12h00 - Salle réunion PMMH 1
    Bioinspired shape shifting of liquid-infused ribbed sheets
    At small scales, capillary forces can deform flexible structures. The aggregation of wet hair into bundles is a daily example. With the miniaturization of technologies, these capillary forces have become important in engineering since they can lead to the catastrophic collapse of structures obtained by lithography (...)
  • Séminaire PMMH - Patrice Meunier (IRPHE)
    Vendredi 10 mars de 11h00 à 12h00 - Salle réunion PMMH 1
    Geoinspired bioreactors : from Earth's precession to stem cell production
    Inspired by the precession of the Earth, a new bladeless mixer has been designed, which consists of a tilted and rotating cylinder. I will first present fundamental studies on the transition to turbulence in such rotating flows. At specific aspect ratios, the resonance of eigen modes creates a strong overturning (...)
  • Séminaire PMMH - Patrice Meunier (IRPHE)
    Vendredi 10 mars de 11h00 à 12h00 - Salle réunion PMMH 1
    Geoinspired bioreactors : from Earth's precession to stem cell production
    Inspired by the precession of the Earth, a new bladeless mixer has been designed, which consists of a tilted and rotating cylinder. I will first present fundamental studies on the transition to turbulence in such rotating flows. At specific aspect ratios, the resonance of eigen modes creates a strong overturning (...)
  • Séminaire PMMH - Agnese Seminara, University of Genoa
    Vendredi 17 février de 11h00 à 12h00 - Salle réunion PMMH 1
    A fish with legs and alternation strategies for navigating turbulence
    Sea robins are fishes with sensory appendages (“legs”) that they use to walk and to dig live prey from within the substrate. Their preadation strategy is so effective that they are often followed by other fish trying to steal their prey. I will discuss a set of behavioral experiments suggesting that these animals (...)
  • SEMINAIRE SIMM / PMMH - Cari Dutcher (University of Minnesota)
    Mardi 14 février de 14h00 à 15h00 - Charpak
    
  • Séminaire PMMH - André Estevez-Torres et Guillaume Sarfati - Laboratoire Jean Perrin, SU et CNRS, Paris
    Vendredi 10 février de 11h00 à 12h00 - Salle réunion PMMH 1
    La recherche face à l'anthropocène : retour d'expérience du bilan carbone du laboratoire Jean Perrin
    Les années se suivent et ne se ressemblent pas. Les records de température, été comme hiver, ne cessent d'être battus et les conséquences sur les écosystèmes et le vivant sont de plus en plus constatées, qualitativement par tout un chacun, et quantitativement par une science compilée dans les rapports successifs du GIEC et (...)
  • Séminaire PMMH - Pascal Hersen (Institut Curie)
    Vendredi 3 février de 11h00 à 12h00 - Salle réunion PMMH 1
    Playing with cellular functions and genetic circuits in real time
    Gene expression plays a central role in the orchestration of cellular processes. In the past years, we have developed several methods to dynamically perturb, manipulate and control genetic circuit and cellular functions in yeast and bacteria using microfluidics and optogenetics. We developed an experimental method (...)
  • Séminaire PMMH - Valentin LAPLAUD (Ladhyx Polytechnique)
    Vendredi 20 janvier de 11h00 à 12h00 - Salle réunion PMMH 1
    Growth and mechanics of 'plants on a chip'
    Plant growth is a complex process depending in part on the hydraulics and mechanics of the plant cell, that has been modeled by Lockhart (1965) and Ortega (1985) using a description still used today. To study it experimentally at the cell and organism level we developed a microfluidic system to follow several (...)
  • Séminaire PMMH - Bruno Andreotti (LPENS)
    Vendredi 13 janvier de 11h00 à 12h00 - Salle réunion PMMH 1
    SARS-CoV-2 at the crossroads between epidemiology, biology and aerosol turbulence
    Five epidemic waves have occurred in 2022, with the second autumn wave (BQ.1.1) currently in decline. The 2023 waves will be made up of a soup of sub-variants showing an evolutionary convergence giving them an immune escape in the upper respiratory tract (XBB.1.5 will become the dominant strain in january). I will (...)
  • Séminaire PMMH - Serge Berthier (INSP)
    Vendredi 6 janvier de 11h00 à 12h00 - Salle réunion PMMH 1
    Natural Photonics
    Photonics, the art of manipulating light, is a relatively recent science. To manage light, to confine it, to slow it down, to orient it... you have to put yourself on its scale, that of the wavelength, that is to say, to create periodic structures (like an electromagnetic wave) who's the period is of the order of (...)

• 2022

  • Séminaire PMMH - Antoine Gaillard, University of Amsterdam
    Vendredi 16 décembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Applications and rheological characterisation of polymer solutions
    Polymer solutions, such as saliva or egg white, belong to an important category of non-Newtonian liquids called viscoelastic liquids. Such liquids are known to exhibit a strong “strain-hardening” behaviour in extensional flows, meaning that strong stresses can arise due to the stretching and progressive unravelling (...)
  • Séminaire PMMH - Emmanuèle Helfer (CINAM, Marseille)
    Vendredi 9 décembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Biomimicking red blood cell filtration by the spleen
    Blood circulation in our vascular system is a physical tour de force. To distribute oxygen throughout the body, Red blood cells (RBCs) continuously travel through the microcirculation, through thin capillaries that are smaller than their size, and are thus highly deformable. Their deformability is periodically (...)
  • Séminaire PMMH - Virgile Thiévenaz INRAE, PIAF, Clermont-Ferrand
    Vendredi 2 décembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Pinch-off of complex suspensions drops
    Many fluids of our everyday life, from paint to concrete, actually contain solid particles suspended in a liquid. Applications such as inkjet printing require the fragmentation of such suspensions into droplets. Depending on the scale at which one looks at it, a suspension may seem homogeneous or heterogeneous. (...)
  • Séminaire PMMH - Frédéric Moisy (FAST, Univ. Paris Saclay)
    Vendredi 25 novembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1

    Sillages, vagues et vent

    Le livre "L'impermanence du Monde - La physique de l'éphémère" invite à une promenade à travers quelques phénomènes naturels régis par la physique des fluides : Pourquoi les rivières dessinen(...)
    Sillages, vagues et vent
    Le livre "L'impermanence du Monde - La physique de l'éphémère" invite à une promenade à travers quelques phénomènes naturels régis par la physique des fluides : Pourquoi les rivières dessinent-elles des méandres ? D'où viennent les lignes lumineuses au fond des piscines ? Combien de temps faut-il pour façonner un galet ? (...)

  • Séminaire PMMH - Maylis Landeau IPGP
    Vendredi 18 novembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Instability, mixing and fragmentation in planetary collisions
    The Earth formed by high-energy collisions between planetary embryos. I will present laboratory experiments on the fluid dynamics of these collisions. I will show that the impact of a liquid volume onto a liquid pool reproduces the cratering observed in numerical simulations and at the surface of planets. Unlike (...)
  • Séminaire PMMH - Sergei Nechaev (LPTMS, CNRS - Université Paris-Saclay)
    Vendredi 21 octobre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Anomalous scaling in stretching of a fractal polymer around a disc
    While stretching of a polymer along a flat surface is hardly different from the classical Pincus problem of pulling chain ends in free space, the role of curved geometry in conformational statistics of the stretched chain is an exciting open question. We use scaling analysis and computer simulations to examine [1] (...)
  • Séminaire PMMH - Laurent Seuront (LOG, Wimereux))
    Vendredi 14 octobre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    The Behavioral Mandala : a new step towards the understanding of the behavioural complexity behind invertebrates and vertebrates foraging strategies
    Movement is a fundamental characteristic of life. It determines the fate of individuals through its influence on reproduction, feeding and survival, and ultimately populations, communities, and ecosystems. An important open question lies in the quantification of both the geometric and stochastic components of (...)
  • Séminaire PMMH - Lydie STARON (Institut d'Alembert)
    Vendredi 7 octobre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Cohesion-induced weakening ? Clues from the failure of a cohesive granular step
    The failure of 2D numerical cohesive granular steps collapsing under gravity is simulated for a large range of cohesion. Focusing on the cumulative displacement of the grains, we establish a sensible criterion for capturing the failure characteristics. We are able to locate the failure in time and to identify the (...)
  • Séminaire PMMH - (Benjamin Favier, CNRS, IRPHE, Marseille)
    Vendredi 30 septembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Interactions between thermal convection and a melting front
    A pure and incompressible material is confined between two plates such that it is heated from below and cooled from above. When its melting temperature is comprised between these two imposed temperatures, an interface separating liquid and solid phases appears. Depending on the initial conditions, freezing or (...)
  • Séminaire PMMH - Blaise Delmotte, LadHyX
    Vendredi 23 septembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Unexpected trapping of active particles and efficient sorting of flexible fibers with obstacles
    The motion of active or elastic particles through structured environments is ubiquitous in nature and industrial applications. Their dynamics result from the complex interplay between internal elastic stresses, activity, contact forces, thermal fluctuations and hydrodynamic interactions with the obstacles. In (...)
  • Séminaire PMMH - Leonid Berlyand, Penn State
    Vendredi 16 septembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    
  • Séminaire PMMH - M.C. Jullien, U. Rennes 1
    Vendredi 9 septembre 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Phase separation of an ionic liquid mixture assisted by a temperature gradient
    Ionic liquids have remarkable properties and are commonly harnessed for green chemistry, lubrication, and energy applications. In this presentation, we report a thermoresponsive ionic liquid (IL) solution which has the property of phase separating above a critical temperature, an interesting feature for the (...)
  • Séminaire PMMH - Anshuman Pal, University of Chicago, US
    Vendredi 8 juillet 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Faceted wrinkling at a contracted curved boundary : isometry and hysteretic wavelength selection
    Thin elastic sheets are fascinating because they can show a rich variety of patterns and multi-scale physics from the interplay of only a few basic ingredients, viz., stretching, bending, and geometry. In this talk, through the behaviour of a simple system of a circular annulus contracted at the inner boundary, we (...)
  • Séminaire PMMH - Gilles Tessier (Sorbonne Univ.)
    Vendredi 1er juillet 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Measuring and shaping the phase of light : new tools to study materials and biological systems
    Spatially-resolved techniques to control and image the phase of light have deeply transformed microscopy. In this talk, I will briefly clarify the notion of optical phase and present two phase-sensitive techniques, both offering high sensitivity and 3D capabilities. Using holography, individual magnetic nanorods (...)
  • Séminaire PMMH - Al Crosby (U. Mass. Amherst)
    Vendredi 24 juin 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Autonomously Moving and Assembling Soft Matter Systems
    
  • Séminaire PMMH - Maxime Hubert, FAU, Université d'Erlangen-Nürnberg, ALL
    Vendredi 17 juin 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Mesoscale strategies of collective transport on deformable liquid interfaces
    Transport at interfaces is crucial in multiple areas of physics and biology and is observed across a wide range of length scales. In the strategies used in such dynamics, the role of hydrodynamic interactions, interface deformations, and the presence of other agents at the interface provide the means to mediate (...)
  • Séminaire PMMH - Ludovic Moreau, ISTerre Grenoble
    Vendredi 10 juin 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Analysis of the micro-seismicity in sea ice with deep learning and Bayesian inference. Application to the monitoring of sea ice thickness, density, and mechanical properties
    In the context of global warming, monitoring the thickness and mechanical properties of sea ice is a major challenge in modern climatology. In particular, the heavy logistical constraints of polar environments, and the lack of accuracy of satellite remote monitoring methods, are obstacles to improving climate (...)
  • Séminaire PMMH - Jacques Treiner
    Vendredi 3 juin 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Les trajectoires les plus pessimistes du GIEC ne sont pas réalistes : bonne nouvelle ?
    L'anticipation du changement climatique repose en partie sur les scénarios d'émissions de gaz à effet de serre utilisés par le Groupe d'experts intergouvernemental sur l'étude du climat (GIEC). Il apparait que les réserves de combustibles fossiles estimées par le World energy outlook et le Statistical review of world (...)
  • Séminaire PMMH - Bruno Moulia (INRAE)
    Vendredi 20 mai 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    The dimensionless numbers of the shaping of plant axes and crowns through tropism and elasticity : a physicist approach of the biological regulation of plant morphogenesis.
    The shape of plant stems and/or of the whole crown of isolated trees are conspicuous traits of each species, while at the same time-varying a lot depending on the environment in which the plant grew. A major process involved in this shaping is stem tropism, i.e. oriented growth directed by external clues. In plant (...)
  • Séminaire PMMH - Olivier Devauchelle (IPGP, Paris)
    Vendredi 13 mai 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Swimming in a wave field
    When a bath of silicon oil vibrates vertically, a droplet of the same oil can bounce indefinitely on its surface [1]. As it does so, it generates a Faraday wave around itself, which then pushes the droplet across the surface. Guided by this wave, the droplet interacts with its own trajectory, with the boundaries, (...)
  • Séminaire PMMH - Alexandre Nicolas (U. Lyon 1)
    Vendredi 22 avril 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Physical modelling of pedestrian dynamics : Make your way through the crowd !
    Physics has constantly been pushing back its boundaries, so much so that active systems of biological interest have come under its scrutiny in the past decades. At present, among its outermost interfaces, research into the dynamics of pedestrian crowds aspires to provide physical insight into issues of major (...)
  • Séminaire PMMH - Jens Eggers, U. of Bristol, UK
    Vendredi 15 avril 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Theory of bubble tips in strong viscous flows
    A free surface, placed in a strong viscous flow (such that viscous forces overwhelm surface tension), often develops ends with very sharp tips. For example, observe a bubble in a shampoo bottle, turned upside down. We shown that the axisymmetric shape of the ends, non-dimensionalized by the tip curvature,is (...)
  • Séminaire PMMH - Luca Cipelletti (Univ. Montpellier)
    Vendredi 8 avril 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    
  • Séminaire PMMH - Stefan Catheline (INSERM, Univ. Lyon1)
    Vendredi 1er avril 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Wave elastography applied to soft tissues and membrane
    Elastography, sometimes referred as seismology of the human body, is an imaging modality now implemented on medical ultrasound systems, on MRI and recently in optical coherence tomography devices. It allows to measure shear wave speeds within soft tissues and gives a tomography reconstruction of the shear (...)
  • Séminaire PMMH : Raphaël Jeanneret, LPENS
    Vendredi 25 mars 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    
  • Séminaire PMMH - Arnaud Lazarus (Institut d'Alembert, Sorbonne Université)
    Vendredi 18 mars 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    New insights on the dynamic stability of time-periodic systems
    Periodically time-varying systems are a class of mathematical problems that underlie many important phenomena and applications in physics, such as parametric instabilities, acoustic tweezers, mass spectrometers and Paul traps or any Floquet engineered systems in Quantum Mechanics. Eventually, the mechanics (...)
  • Séminaire PMMH : Valentin Leroy, MSC, Université de Paris
    Vendredi 11 mars 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    
  • Séminaire PMMH, Marianne Grognot (LBE - ESPCI)
    Vendredi 11 février 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    A multiscale chemotaxis assay to unravel how motile bacteria navigate their environment(s)
    Flagellated bacteria swim by rotating one or several flagella ; motility alone results in a random walk, but the flagella's rotation can be influenced by an intracellular sensory system that enables cells to climb or descend chemical gradients, in a process called chemotaxis. Altogether, motility and chemotaxis (...)
  • Séminaire PMMH Jasna Brujic
    Vendredi 4 février 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    
  • Séminaire PMMH - Julian Talbot (LPTMC, Sorbonne Univ.)
    Vendredi 21 janvier 2022 de 11h00 à 12h00 - Salle réunion PMMH 1
    Statistics and Optimisation of Random Pan Stacking
    The stacking of objects is a familiar operation. For example, a common conundrum of daily life is how to arrange a collection of pots and pans so that the stack will fit in a kitchen cupboard. Because of the varying form and convex nature of the pans, the height will vary depending on the order in which they are (...)

• 2021

  • Séminaire PMMH - Varda Hagh (Univ. of Chicago)
    Vendredi 10 décembre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Free-then-freeze : transient learning degrees of freedom for introducing function in materials
    Many protocols used in material design and training have a common theme : they introduce new “learning'' degrees of freedom, often by relaxing away existing constraints, and then evolve these degrees of freedom based on a rule that leads the material to a desired state at which point these learning degrees of (...)
  • Séminaire PMMH - Edouard Ravier (Université du Mans)
    Vendredi 3 décembre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    What can we learn from the experimental modelling of subglacial hydrology ?
    The configuration and evolution of the hydrological system under ice sheets is a key control on ice flow dynamics, erosion, sedimentation and bed deformation. Due to the inaccessibility of the subglacial environment, the understanding of subglacial meltwater drainage and its interaction with the ice and the (...)
  • Séminaire PMMH - Tom Witten (University of Chicago)
    Vendredi 26 novembre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Latent sculpture in a curved crease
    Thin sheets have an inherent tendency to shape themselves. When forced, they seek to deform in a way that bends without stretching. Thus a crushed sheet shapes itself into a crumpled shape made of flat facets bounded by sharp edges. These sharp features fail to avoid stretching : the deformation energy of (...)
  • Séminaire PMMH David Richard (Liphy, Grenoble)
    Vendredi 12 novembre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Using soft excitations to predict and understand plastic flow in disordered solids
    Imposing an external driving, amorphous solids can flow via a succession of plastic rearrangement of localized particles. Numerous numerical and experimental studies have shown that loci of plastic instability in glasses are triggered by spatially localized soft spots in direct analogy with dislocations present in (...)
  • Séminaire PMMH Rémi Carminati (Institut Langevin, ESPCI)
    Vendredi 22 octobre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Seeing through disordered scattering materials
    The propagation of coherent light through a scattering medium produces speckle patterns in reflection and transmission. Despite the apparent randomness of the speckle patterns, a statistical correlation between the reflected and transmitted intensities survives even in the multiple scattering regime. This mutual (...)
  • Séminaire PMMH - Marco Faustini (LCMCP, Sorbonne Univ.)
    Vendredi 15 octobre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Evaporation-driven processes towards photonic colloidal assemblies
    Developing patterning methods to obtain periodic and ordered colloidal films could open perspectives for their utilization in fields ranging from electronics, photonics, microfluidics or dew-harvesting (1). For instance, integrating porous nanoparticles (oxides or Metal-Organic Frameworks) in periodic structures (...)
  • Séminaire PMMH Elim Hong (IBPS, Sorbonne Université)
    Vendredi 24 septembre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    The yin yang pathway in the aversive brain
    The habenulo-interpeduncular (Hb-IPN) pathway is an evolutionarily conserved neural pathway mediating diverse pathophysiological behaviors including locomotion, fear, anxiety and nicotine addiction. The left and right habenular nuclei consists of hundreds of neurons that send long axons to project to its target, (...)
  • Séminaire PMMH - Valentina Di Santo (Stockholm University)
    Vendredi 10 septembre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    How fishes save energy : exploring biomechanical and physiological performance of locomotion
    Swimming ability has contributed to the evolutionary success of fishes, and its mechanics have been studied extensively across groups. Fishes exhibit an astounding diversity of locomotor behaviors, from classic swimming with their body and fins to jumping, flying, walking, and collective behaviors such as (...)
  • Séminaire PMMH - Hillel Aharoni (Weizmann Inst.)
    Vendredi 3 septembre 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    On wrinkles, and what they have to do with liquid crystals
    A thin elastic sheet attached to a soft substrate often develops wrinkle patterns when subject to an external forcing or as a result of geometric incompatibility. Such patterns appear spontaneously in a variety of natural systems, ranging from plant tissues to drying paint and from milk skin to human skin. The (...)
  • Séminaire PMMH Lucilla de Arcangelis (Univ. of Naples)
    Vendredi 9 juillet 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Acoustic fluidization and remote earthquake triggering
    Lucilla de Arcangelis, Eugenio Lippiello, Massimo Pica Ciamarra Engineering Department University of Campania “Luigi Vanvitelli” Occasionally, a major earthquake can trigger additional events at distances up to 1000 km away. How that happens is a longstanding puzzle since the amplitude of the seismic waves (...)
  • Séminaire PMMH - Eva Adnan Kanso (Univ. of Southern California)
    Vendredi 25 juin 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    One Fish, Two Fish
    I will tell two short stories of fish hydrodynamics. First, I will argue, based on biological observations and mathematical models, that fish that actively flap their tail in concert with passive hydrodynamic forces can simultaneously improve swimming speed and efficiency. Second, I will show that passive (...)
  • Séminaire PMMH - Thomas Paehtz (Zhejiang University)
    Vendredi 11 juin 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Unified model of sediment transport threshold and rate across subaqueous bedload, windblown sand, and windblown snow
    Loose sedimentary grains cover much of the wind-blown (i.e., aeolian) and water-worked (i.e., fluvial) sedimentary surfaces of Earth and other planetary bodies. To predict how such surfaces evolve in response to aeolian and fluvial flows, one needs to understand the rate at which sediment is transported for given (...)
  • Séminaire PMMH - Philippe Gondret (FAST, Univ. Paris-Saclay)
    Vendredi 30 avril 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Tsunami generation by landslides : From laboratory experiments to geophysical events
    Tsunami waves can arise from significant geological events such as the collapse of a mountain flank or a volcano into a lake or an ocean. We reproduce this situation at the laboratory scale. The landslide is modeled by the sudden release of a rectangular granular column, which then impacts a still water layer and (...)
  • Séminaire PMMH - Jérôme Weiss (ISTerre, Grenoble)
    Vendredi 19 mars 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Is mechanics driving the Arctic sea ice decline ?
    In the Arctic, sea ice is undergoing for several decades a dramatic decline both in terms of spatial extent and average thickness. As sea ice strongly affects the exchanges of energy and momentum between the ocean and the atmosphere, its decline is accompanied by a particularly strong warming in the Arctic. The (...)
  • Séminaire PMMH - Jérémy Hure (CEA Saclay)
    Vendredi 5 mars 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Plasticity and ductile fracture in irradiated metals
    Metals used in nuclear reactors core are subjected to neutron irradiation, leading to different kind of crystallographic defects depending on irradiation conditions. The main irradiation defects include dislocation loops and nano-voids. These defects have a strong influence on plasticity mechanisms, and, in turn, (...)
  • Séminaire PMMH - Matilda Backholm (Aalto Univ., Helsinki, Finland)
    Vendredi 12 février 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    When honey moves faster than water
    The viscosity of a fluid is well known to limit its flow : the more viscous a droplet, the slower it moves [1,2]. Here, we show that this intuitive rule breaks down in a confined liquid-repellent geometry. A gravity-driven, highly viscous glycerol droplet placed in a sealed superhydrophobic capillary moves more (...)
  • Séminaire PMMH - Emmanuelle Rio (LPS-Univ. Paris Saclay)
    Vendredi 5 février 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Rupture of Foam Films and Surface Bubbles
    Surface bubbles are of crucial interest since they favours the transport of material from the bulk to the overlying atmosphere through the production of aerosols. This is important for example in climate models, air pollution studies or in the carbonated beverage industry since the produced aerosols contain most (...)
  • Séminaire PMMH - Joe Tavacoli (München, Germany)
    Vendredi 29 janvier 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Programmable design and performance of modular magnetic microswimmers
    Synthetic microswimmers are promising agents for targeted in-vivo healthcare as well as important frameworks from which to advance the understanding of locomotion strategies at the microscopic scale.[1,2] Nevertheless, constructing these types of devices with flexibility of design and in large numbers remains a (...)
  • Séminaire PMMH - Baptiste Darbois-Texier (FAST)
    Vendredi 22 janvier 2021 de 11h00 à 12h00 - Salle réunion PMMH 1
    Surface instability of shear-thickening suspensions down an inclined plane
    A shear-thickening suspension, such as cornstarch particles in water, exhibits a very strange behavior : it flows as milk when gently stirred but turns rock solid under impact. Despite its notoriety, this phenomenon has been understood only recently. Based on this progress, we decided to explore the behavior of (...)

• 2020

  • Séminaire PMMH - Lorraine Montel (UPMC)
    Vendredi 11 décembre 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    Emulsion droplets as a model biomimetic system
    Emulsion droplets recapitulate the deformability and surface fluidity of biological objects, in a simpler and tunable fashion. Thus, they can be used as a model biomimetic system to study cell-cell interactions. During this talk, I will demonstrate this use in two different systems : the study of phagocytosis, and (...)
  • Séminaire PMMH - A.M. Goryaeva (Université de Rouen)
    Vendredi 27 novembre 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    Reinforcing materials modelling by encoding the structures of defects in crystalline solids into distortion scores
    A perfect crystal is a purely theoretical concept. Real-world crystals contain imperfections, also called defects. Identification and characterization of defects provide the crucial information for interpretation of simulations and experiments that bridge the gap between atomic- and micrometer-scales. But what is (...)
  • Séminaire PMMH - Joseph d'Alessandro
    Vendredi 13 novembre 2020 de 11h00 à 12h00 - Salle réunion PMMH 1

    Eukaryotic cells as interacting living particles

    Cells move. They propel themselves using an internal machinery which endows them with the characteristics of active particles. At the same time, they interact dynamically with (...)
    Eukaryotic cells as interacting living particles
    Cells move. They propel themselves using an internal machinery which endows them with the characteristics of active particles. At the same time, they interact dynamically with their environment and with neigbouring cells, by adhering, exerting forces and exchanging biochemical signals. In this talk, we will first (...)

  • Séminaire PMMH - Costantino Creton (SIMM ESPCI)
    Vendredi 6 novembre 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    Using light to detect molecular forces, chemical bond scission and to understand fracture
    Costantino Creton Soft Matter Science and Engineering, ESPCI Paris, Université PSL, Paris, F Recent advances in chemistry have made it possible to directly optically visualize forces on chemical bonds or even bond scission by using molecules that either emit light or become fluorescent when activated by the (...)
  • Séminaire PMMH-Cécile Sykes (Institut Curie, Paris)
    Vendredi 27 mars 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    Active or passive deformation of the cell membrane supplied by actin assembly. Perpectives on nucleus deformation
    In all cell functions, a common observation is that cytoskeleton assembly correlates with membrane deformation based on active forces. The exact role, in particular, of the actin cytoskeleton in cell membrane deformation, with pushing or pulling forces, is what we address both experimentally and theoretically. We (...)
  • Séminaire PMMH - Chung-Yuen Hui (Cornell University)
    Vendredi 13 mars 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    Mechanical Properties of Fiber-Reinforced Soft Composites
    In this talk I will focus on an emerging class of fiber reinforced composites where the matrix is extremely soft and tough. For example, an upper estimate for fiber/matrix modulus ratio in traditional fiber reinforced polymer composites is at most 100. Matrices made from tough elastic gels can have modulus (...)
  • Séminaire PMMH, Arthur Lebée ENPC
    Vendredi 6 mars 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    Continuum elasticity of Miura Tessellations
    Origami tessellations are curved two-dimensional discrete shells folded out of a periodic crease pattern. Unlike solid shells, Origami tessellations can morph and access a space of configurations each characterized by the list of folding angles of all creases. Due to inextensibility constraints imposed by Origami (...)
  • Séminaire PMMH- Paulo E. Arratia (UPenn)
    Vendredi 28 février 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    A microstructural view of yielding and plasticity in 2D disordered materials
    When stressed sufficiently, amorphous materials yield and deform plastically via reorganization of microscopic constituents. Despite much effort, understanding the interdependence of yielding, plasticity, and microscopic structure in non-equilibrium states (i.e. under stress) remains a major challenge. In this (...)
  • Séminaire PMMH- Elisabeth Guazzelli (MSC)
    Vendredi 7 février 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    Particle motion in vortical flows
    In many natural phenomena or industrial applications, heavy particles are transported in complex flows. The flow structures may happen to promote the stirring and dispersion of the particles. But the opposite can also take place and the flow configuration may contribute to the focussing and accumulation of (...)
  • Séminaire PMMH- Dwight Barkley (University of Warwick)
    Vendredi 31 janvier 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    A fluid mechanic's analysis of the tea-cup singularity
    In 1926 Einstein published a short paper explaining the meandering of rivers. He famously began the paper by discussing the secondary flow generated in a stirred tea cup — the flow now widely known to be responsible for the collection of tea leaves at the center of a stirred cup of tea. In 2014, Luo and Hou (...)
  • Séminaire PMMH- Kristina Davitt (ENS)
    Vendredi 24 janvier 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    Wetting hysteresis and dynamics : interpreting dissipation mechanisms at the contact line
    A liquid moving over a solid substrate is an everyday occurrence, and the hysteresis and dynamics of the three-phase contact line have been measured in innumerable experiments over the years. In addition, the ingredients needed to describe the phenomenon are known : in the most basic picture, there is viscous (...)
  • Séminaire PMMH - Doron Grossman (Collège de France)
    Vendredi 17 janvier 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    From Molecules to Helical Ribbons - Shape and Shape Fluctuations
    * Self assembly of molecules into supramolecular structures is an important process through which non trivial structures are formed in nano-metric scale. The resulting structure depends on chemical and physical principles that govern the process, and may be sensitive to the exact conditions in which they are (...)
  • Séminaire PMMH Nicolas Triantafyllidis (LMS polytechnique)
    Vendredi 10 janvier 2020 de 11h00 à 12h00 - Salle réunion PMMH 1
    STABILITY PROBLEMS IN MECHANICS : MULTIPHYSICS AND MULTISCALE ASPECTS (A MECANICIAN'S PERSPECTIVE…)
    Stability is a fascinating topic in solid mechanics that has its roots in the celebrated Euler column buckling problem, which first appeared in 1744. Over the years advances in technology have led to the study of ever more complicated structures first in civil and subsequently in mechanical engineering applications. (...)

• 2019

  • Séminaire PMMH - Jean-Philippe Bouchaud
    Vendredi 20 décembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Crises et phénomènes socio-économiques collectifs
    Comme l'écrivait P. W. Anderson en 1972 dans « More is different », le comportement de grandes assemblées d'individus ne peut pas être compris à partir de l'extrapolation du comportement d'individus isolés. Au contraire, des comportements complètement nouveaux, parfois spectaculaires et difficiles à anticiper, peuvent (...)
  • Séminaire PMMH - Séverine Atis (Harvard University)
    Vendredi 13 décembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    On Growth and Form of Range Expansions at Liquid Interfaces
    Range expansions coupled with fluid flows are of great importance in understanding the organization and competition of microorganism populations in liquid environments. However, combining growth dynamics of an expanding assembly of cells with hydrodynamics leads to challenging problems, involving the coupling of (...)
  • Séminaire PMMH, Vinod Kumar Saranathan (Yale NUS College)
    Vendredi 6 décembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Biomimetic and Bio-inspired Potential of Self-assembled Biophotonic Nanostructures
    Colors in Nature can be produced either chemically, by the selective light bsorption by pigments, or physically, by light interference from biophotonic nanostructures. Intriguingly, there are almost no known violet, blue or green pigments in animals. And yet these structurally produced colors are ubiquitous in (...)
  • Séminaire PMMH — Miguel Fernandez (équipe-projet Commedia, INRIA Paris)
    Vendredi 22 novembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Numerical methods for fluid-structure interaction with immersed elastic bodies
    The mechanical interaction of an incompressible fluid flow with an elastic structure is a multi-physic problem omnipresent in nature and in many engineering fields. One can think, for instance, of the opening/closing dynamics of heart valves when blood is propelled into the arteries and of the wings of a bird (...)
  • Séminaire PMMH - Jérôme Fresnais (PHENIX, UPMC)
    Vendredi 15 novembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Making superhydrophobic surfaces with magnetic elastomer : towards controlled droplet movement
    In the field of superhydrophobic surfaces, natural surfaces exhibiting non-wetting filament networks remain a challenge to understand. Indeed, if classical superhydrophobic surfaces developed roughness at different scales, superhydrophobicity on hairy surfaces shows elastic behavior that is more difficult to (...)
  • Séminaire PMMH -Julien Bobroff (LPS, Univ. Paris-Sud/Paris-Saclay)
    Vendredi 8 novembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    La physique autrement
    Pourquoi vulgariser la physique autrement ? Et surtout comment ? Voilà les deux questions au coeur des activités de notre équipe de recherche. Nous y explorons de nouvelles formes de vulgarisation en lien avec le monde du design et de la création. Parmi nos dernières productions, un objet de médiation sur la (...)
  • Séminaire PMMH- Pedro Saenz (University of North Carolina at Chapel Hill)
    Vendredi 25 octobre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Hydrodynamic Spin Lattices
    Mesoscale and macroscale analogs of electronic spin systems, such as ultra-cold fermionic lattice gases and mechanical metamaterials, offer direct insights into fundamental physical prin ciples while simultaneously promising groundbreaking applications, from quantum computation and simulators to photonic and (...)
  • Séminaire PMMH - Jean Comtet (EPFL)
    Vendredi 4 octobre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Soft matter and mechanics at the molecular scale : from the rheology of few-atoms gold junctions to the observation of single proton transport at solid/water interfaces.
    Jean Comtet École Polytechnique Fédérale de Lausanne, Département Sciences et Techniques de l'Ingénieur, CH-1015 Lausanne New paradigms are expected to emerge at the nanometer scale for soft matter and mechanics, stemming from the breakdown of continuum concepts and the appearance of new force scales. I will present (...)
  • Séminaire PMMH - Natsuhiko Yoshinaga (Tohoku University)
    Lundi 30 septembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Model Selection of PDE for Pattern Forming Systems
    Partial differential equations (PDE) have been widely used to reproduce patterns in nature, and to give an insight on the mechanism underlying pattern formation. Although enormous number of PDE models have been proposed, they rely on pre-request knowledge of physical laws and symmetries, and one has difficulties (...)
  • Séminaire PMMH-Arezki Boudaoud (ENS Lyon)
    Vendredi 27 septembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    From tissue mechanics to plant morphogenesis
    The form of organisms relies on the mechanical properties of their cells and tissues. In order to help understanding how plants grow and reach well-defined shapes, we developed a set of experimental and theoretical approaches to quantify tissue mechanics in living plants at multiple scales and to relate such (...)
  • Séminaire PMMH - David Saintillan (University of California San Diego)
    Vendredi 20 septembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Viscous dynamics of passive and active microfilaments
    Elastic filaments and semiflexible polymers are ubiquitous in biology, where they play a role in cell mechanics and locomotion as well as for fluid transport on the microscale. In this talk, I will discuss two problems involving the interaction of such filaments with fluid flows. The first problem focuses on the (...)
  • Séminaire PMMH - Patrick Bot (Institut de Recherche de l'Ecole Navale)
    Vendredi 13 septembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    From sails aerodynamics to the Lift Crisis (and other results on the lift generated by a highly curved plate)
    Yacht sails show some peculiarities among aerodynamic systems. Rather flat sails are used to sail upwind, and the flow remains mostly attached. To sail downwind, highly cambered sails may be used where flow separation is significant. Some results will be shown on the flow around a spinnaker and the related fluid (...)
  • Séminaire PMMH - Yukitaka Ishimoto (Akita Prefectural University)
    Vendredi 6 septembre 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Biomechanical excursions : from cell shapes to dragonfly wings
    In the last decade, much attention has been paid to the physical/mechanical aspects of biological phenomena inside/outside living bodies, owing to the latest technological developments. For example, it becomes possible to directly measure the forces generated by cells on specially designed substrates, or to infer (...)
  • Seminaire Yahya Modarres-Sadeghi
    Lundi 26 août 2019 de 11h00 à 12h00 - Salle réunion PMMH 3
    
  • Séminaire PMMH - Farzam Zoueshtiagh (IEMN, Lille)
    Vendredi 5 juillet 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Dynamics and stability of a liquid-gas interface in the presence of micro-particles
    This French-Japan-US collaborative study examines the influence of the micro-particles on the stability of the liquid-air interface. We will first revisit the effect of these particles on the dynamics of the interface in a confined "1D" geometry [1] with the formation of armored bubbles (fig. 1(a)) and will show (...)
  • Séminaire PMMH - Allbens Atman (Centro Federal de Educação Tecnológica de Minas Gerais, Brasil)
    Vendredi 28 juin 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Experimental validation of nonextensive scaling law in confined granular media : emergence of shear bands
    The statistics of grain displacements probability distribution function (pdf) during the shear of a granular medium displays an unusual dependence with the shear increment upscaling as recently evinced [Phys. Rev. Lett. 115 238301 2015]. Basically, the pdf of grain displacements has clear nonextensive (q-Gaussian) (...)
  • Séminaire PMMH-Nicolas Vandewalle (Université de Liège)
    Vendredi 21 juin 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Milliswimmers : Self-assembling complex and functional structures at the (sub)millimeter scale
    When soft ferromagnetic particles are suspended at air-water interfaces in the presence of a vertical magnetic field, dipole-dipole repulsion competes with capillary attraction such that structures self-assemble. The complex arrangements of such floating bodies are emphasized. By adding a horizontal and (...)
  • Séminaire PMMH - Denis Guthleben (CNRS)
    Vendredi 7 juin 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Le CNRS, 80... et quelques années d'histoire
    Créé par un décret du 19 octobre 1939, le CNRS voit le jour dans un monde qui vient de basculer dans l'abîme : six semaines plus tôt, l'Allemagne nazie a envahi la Pologne et, dans la foulée, l'Angleterre et la France lui ont déclaré la guerre. Dans ce contexte, le nouvel établissement doit piloter la mobilisation (...)
  • Séminaire PMMH- Tom Mullin (Univ Oxford)
    Vendredi 31 mai 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Levitation by Thin Viscous Layers
    The results of experimental investigations into balancing cuboids, cylinders and spheres‘ on a vertical moving wall which is covered a thin layer of viscous fluid are discussed. It is found that balance can be achieved over a narrow range of speeds in all cases. Systematic results for spheres and cylinders have (...)
  • Séminaire PMMH - Corrado Rainone (ITP Univ. of Amsterdam)
    Vendredi 24 mai 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Addressing the protocol dependence of glass plasticity and yielding
    The glassy slowdown is a phenomenon whereupon a liquid, when supercooled below its melting point, exhibits a dramatic slowdown of its dynamics, such that it rapidly becomes impossible to maintain it equilibrated on feasible experimental timescales. The resulting out-of-equilibrium system is referred to as a glass, (...)
  • Séminaire PMMH - Michaël Baudoin (IEMN - Université de Lille)
    Vendredi 17 mai 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Manipulation of fluid and particles at microscales with selective acoustical tweezers
    The selective contactless manipulation and assembly of physical and biological objects and fluids at micrometric down to nanometric scales promises tremendous development in fields as diverse as microrobotics, microfluidics, tissue engineering or micro/nano- medicine. In this regard, acoustical tweezers is a (...)
  • Séminaire PMMH-Bertrand Maury (Dpt maths, ENS)
    Vendredi 10 mai 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Faster is Slower effect in crowds
    The so-called Faster is Slower (FiS) effect is commonly observed in real-life or experimental situations. In the context of evacuation processes, it expresses that increasing the speed (or, more generally, the eagerness to egress) of individuals may induce a reduction of the flow through the exit door. We propose (...)
  • Séminaire PMMH - Barakat Abdul (Ladhyx, Polytechnique)
    Vendredi 19 avril 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Optimizing the Performance of Endovascular Stents : Cells, Vessels, and Connected Devices
    The pathological complications of atherosclerosis, namely heart attacks and strokes, are the leading cause of mortality in the world. The most common treatment for atherosclerosis is the implantation of a stent, a wire-mesh structure that is deployed on a balloon catheter and expanded at the location of arterial (...)
  • Séminaire PMMH - Priya Subramanian (Univ. of Leeds)
    Vendredi 12 avril 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Modal Interactions and Superlattice Patterns
    Pattern formation in systems in many real world systems such as neural-field models, reaction-diffusion systems and fluid systems such as the Faraday wave system have separation of scales leading to nonlinear modal interactions. A general analysis of possible terms that can arise via modal interactions is subject (...)
  • Séminaire PMMH Michaël Berhanu (MSC)
    Vendredi 5 avril 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Nonlinear interactions and turbulence of capillary surface waves
    The dynamics of the waves propagating on a water surface is often influenced by nonlinear effects. The complex and disordered patterns of gravity waves seen on a choppy sea are indeed interpreted as a statistical dynamic equilibrium of waves in interaction. Using among some others the hypothesis of weak non (...)
  • Séminaire PMMH-Elim Hong (IBPS, Sorbonne Université)
    Vendredi 29 mars 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    The yin yang pathway in the aversive brain
    The habenulo-interpeduncular (Hb-IPN) pathway is an evolutionarily conserved neural pathway mediating diverse pathophysiological behaviors including locomotion, fear, anxiety and nicotine addiction. The left and right habenular nuclei consists of hundreds of neurons that send long axons to project to its target, (...)
  • Séminaire PMMH - Corrado Maurini (Inst. J.-L. d'Alembert UPMC)
    Vendredi 22 mars 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Nucleation and propagation of cracks in the variational approach to fracture
    Damage and fracture in brittle materials are associated to a loss of stiffness and an energy dissipation. These phenomena can be modelled as a minimisation problem on the sum of the elastic and the dissipated energies. This view led a fecund variational theory of fracture and to efficient numerical approximation (...)
  • Séminaire PMMH - Shreyas Mandre (Brown Univ., Providence)
    Vendredi 15 mars 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Surfactants driven out of equilibrium by a flow
    A surfactant is a chemical compound that adsorbs onto a fluid-fluid interface and reduces its surface tension. A non-uniform distribution of such compounds at the interface causes a Marangoni stress that drives a flow, which in turn transports the surfactant. Estimating in situ the degree to which the adsorbed (...)
  • Séminaire PMMH Jean-Arthur Olive (ENS)
    Vendredi 22 février 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    From micro-crack to crustal fault
    Major fault systems dissect the Earth's crust at the boundaries of tectonic plates. On human time scales, faults may slip catastrophically during earthquakes, but fault lines remain steady features of tectonic landscapes. On geological time scales, new fault lines can form, shape mountains and basins as they (...)
  • Séminaire PMMH - Tobias Schneider (EPFL)
    Vendredi 15 février 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    A network of invariant solutions underlying spatio-temporal patterns in inclined layer convection
    Thermal convection in a fluid between two horizontal plates, a lower hot plate and an upper cold plate, exhibits chaotic dynamics and turbulence. If such a convection cell is inclined against gravity, buoyancy forces drive hot and cold fluid up and down the incline leading to a shear flow in the base state and the (...)
  • Séminaire PMMH - Marie Le Merrer (ILM, Univ. Lyon 1)
    Vendredi 8 février 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Flow and surfactant dynamics in bubble rearrangements in foams
    Liquid foams are assemblies of gas bubbles in a soapy solution, found in many applications from cosmetics to oil drilling. The nature of surfactants changes the properties of the liquid-gas interfaces, and consequently the macroscopic properties of the foam like its stability and rheology. However, the flow (...)
  • Séminaire PMMH - Christophe Gissinger (ENS)
    Vendredi 1er février 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Instabilités dans les écoulements entraînés par forçage magnétique
    La conversion d'énergie électromagnétique en énergie cinétique par un fluide conducteur de l'électricité est un phénomène omniprésent que l'on trouve dans plusieurs systèmes naturels ainsi que dans de nombreuses applications industrielles. Malgré l'importance de ces applications, plusieurs aspects des écoulements (...)
  • Séminaire PMMH - Sophie Ramananarivo (LadHyX, École Polytechnique)
    Vendredi 18 janvier 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Emergent order, from fish schools to colloidal crystals
    It has long been thought that fish form into schools and birds into flocks so that each individual can take advantage of the flows produced by others. Using physical experiments that mimic the movements of fins or wings, we discover that flapping bodies not only swim or fly faster when grouped together but that (...)
  • Séminaire PMMH - Bernadette Bensaude-Vincent (Univ. Paris 1)
    Vendredi 11 janvier 2019 de 11h00 à 12h00 - Salle réunion PMMH 1
    Dialogue avec les matériaux
    Cette intervention est une invite à penser les matériaux comme des partenaires de nos aventures techniques. Après un bref historique des conditions d'émergence de la science des matériaux on montrera en quel sens les matériaux sont des hybrides de nature, de technique et de société. Et on illustrera cette condition (...)

• 2018

  • Séminaire PMMH - Emmanuel Virot (EPFL - Harvard University)
    Vendredi 21 décembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Non-destructive prediction of the buckling load of soda cans and space rockets
    What is the critical load required to crush a soda can or a space rocket shell ? Surprisingly, there is no good way to estimate it, because of the high defect-sensitivity of the buckling instability. Here we measure the response of (imperfect) empty Coca-Cola cans to lateral poking and identify a generic stability (...)
  • Séminaire PMMH - Ory Schnitzer ( Imperial College London)
    Vendredi 14 décembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Asymptotic models of wave propagation and resonance in micro-structured media
    The study of microstructured media in acoustic settings is undergoing a considerable revival, with ideas originating from electromagnetism, photonic crystals and metamaterials influencing structured acoustic devices. Fundamentally, these advancements rely on incorporating resonances to effectively control wave (...)
  • Séminaire PMMH - Dimitry Kolomenskiy (JAMSTEC, Japon)
    Vendredi 7 décembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Bumblebee in flight and in digit
    Flight as a mode of animal locomotion emerges from interaction of internal biological systems with the external environment. Although it is currently, or even generally, unrealistic to fully reduce this problem to first principles, it proves possible and useful to combine low-dimensional models of biological (...)
  • Séminaire PMMH - Nicolas Taberlet (UCBL - ENS Lyon)
    Vendredi 30 novembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Morphogenèse glaciaire induite par ablation différentielle
    Les processus d'ablation de la glace sont multiples, la sublimation et la fonte étant dépendantes des conditions climatiques (ensoleillement, température, humidité, précipitations, vent…). Nous avons étudié la morphogenèse des « Zen Stones » qui se forment essentiellement sur le lac Baïkal au cours de la saison hivernale. (...)
  • Séminaire PMMH - Pierre Jop (SVI, Saint-Gobain)
    Vendredi 23 novembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Vers un matériau granulaire humide : quand la capillarité contrôle les interfaces
    Le mélange de grains avec un liquide est souvent la première étape d'un processus industriel, mais la nature triphasique du milieu rend la description globale difficile [1] : la cohésion des ponts capillaires [2] et la progression du liquide dans le système créent des zones de comportements mécaniques différents. De (...)
  • Séminaire PMMH - Lucio Isa (ETH, Zurich)
    Vendredi 16 novembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Breaking the symmetry : Designing colloidal motors and swimming at oil-water interfaces
    Breaking symmetry is at the very core of achieving propulsion at the microscale, where viscous forces dominate. Nature has perfected a range of different strategies to reach this goal for swimming microorganisms, which scientists have taken inspiration from to produce artificial micro-swimmers [1]. A common way to (...)
  • Séminaire PMMH - Mark Pauly (EPFL)
    Vendredi 9 novembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Light, Matter, Form - Computational Design of Functional Geometry
    In this talk, I will outline a general computational approach for material-aware design of complex 3D models. The key step is to identify suitable geometric abstractions of physical properties that enable effective computations with high predictive accuracy. I will show several examples of this approach for (...)
  • Séminaire PMMH - Thomas Lessinnes (EPFL)
    Vendredi 19 octobre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    New tools for the mechanics of biofilaments
    Many biological objects present themselves as elongated slender structures. One may for instance mention proteins, polymers, DNA, bacterial fibres, fungi, stems, roots, arteries or neurons to cite but a few. It so happens that these bio-filaments are often organised as bundles of sub-filaments. The interplay of (...)
  • Séminaire PMMH- Nicolas FRANCOIS (The Australian National University)
    Vendredi 12 octobre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Surfing wave driven turbulence at a fluid surface
    Nicolas FRANCOIS, Hua XIA, Horst PUNZMANN, Michael SHATS Physics of Fluids Laboratory, The Australian National University When a laminar flow becomes turbulent, its energy is spread over a range of scales in a process named energy cascade. It has recently been discovered that turbulent flows can be forced by (...)
  • Séminaire PMMH - Laurent Duchemin (IRPhE, Marseille)
    Vendredi 5 octobre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Deux écoulements capillaires impulsionnels
    Dans cet exposé, je présenterai deux études expérimentales et théoriques sur des écoulements ayant une dynamique rapide à une échelle capillaire. La première concerne l'étirement impulsionnel d'un ligament liquide millimétrique. Dans le contexte général de la fragmentation, cette expérience modèle permet à la fois d'étudier (...)
  • Séminaire PMMH - Sara Jabbari Farouji (Gutenberg University, Mainz, Germany)
    Vendredi 28 septembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Controlling stability and transport of magnetic microswimmers by an external field
    Inspired by intriguing dynamics of magnetotactic bacteria, we present a minimal kinetic model for magnetic swimmers in an external magnetic field to investigate their collective behavior. Our kinetic model couples a Fokker-Planck equation for active particles in an external magnetic field to the Stokes flow. (...)
  • Séminaire PMMH - Marc Durand (MSC, Univ. Paris Diderot)
    Vendredi 21 septembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Milieux cellulaires fluides et réseaux : microstructure et propriétés effectives
    Les propriétés structurelles (géométrie, topologie, désordre) d'un matériau à l'échelle de ses constituants affectent profondément ses propriétés effectives, telles que sa réponse mécanique ou acoustique. Au cours de ce séminaire, je présenterai diverses études visant à caractériser - de manière exacte ou statistique - les (...)
  • Séminaire PMMH - Hans Herrmann (ETH, Zürich)
    Vendredi 14 septembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Structures granulaires renforcées par un fil et éjections granulaires d'un milieu poreux
    Je vais présenter deux sujets granulaires : Le premier c'est la stabilisation d'une colonne granulaire avec un fil. Il s'agit de comprendre avec des expériences et des simulations numériques pourquoi et comment stabilisent des piliers renforcés par ficelle selon une nouvelle technique développée par des architectes. (...)
  • Séminaire PMMH - Fernando Peruani (Univ. de Nice)
    Vendredi 7 septembre 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Towards a non-equilibrium statistical mechanics of biological and biomimetic systems
    Collective phenomena are observed in biological and biomimetic systems at all scales, from bacterial systems to sheep herds in biology, and from Quincke rollers to bristlebots or kilobots in man-made, active systems. Provided that these non-equilibrium systems consist of independent units without a central control (...)
  • Séminaire PMMH : Antonio de Simone (Trieste)
    Vendredi 13 juillet 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Biological and bio-inspired motility at microscopic scales : locomotion by shape control
    Locomotion strategies employed by unicellular organism are a rich source of inspiration for studying mechanisms for shape control. In fact, in an overwhelming majority of cases, biological locomotion can be described as the result of the body pushing against the world, by using shape change. Motion is then a (...)
  • Séminaire PMMH - Federico Toschi (Technische Universiteit, Eindhoven)
    Vendredi 6 juillet 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Turbulence and plastic events in fluid emulsions
    Emulsions made of immiscible fluids can display an very rich phenomenology. In this talk we will discuss how to numerically model fluid emulsions and we will present results from recent numerical studies. The numerical model that we employ is based on the multi-component Lattice Boltzmann method as it provides a (...)
  • Séminaire PMMH - Philippe Marcq (Institut Curie)
    Vendredi 29 juin 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    From cells to tissue : A continuum model of epithelial mechanics
    A continuum model of epithelial tissue mechanics is formulated using cellular-level mechanical ingredients and cell morphogenetic processes, including cellular shape changes and cellular rearrangements. This model incorporates stress and deformation tensors, which can be compared with experimental data. Focusing (...)
  • Séminaire PMMH - Alexander Alexeev (Georgia Tech)
    Vendredi 22 juin 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Biomimetic flapping and beating in viscous fluid
    We probe interactions of elastic structures with viscous fluids to investigate biomimetic approaches for fluid manipulation. We consider two systems : fish-like elastic fines and artificial cilia. Fish displays incredible agility and speed using oscillating flexible fins. We represent fins as thin elastic plates (...)
  • Séminaire PMMH - Ludovic Bellon (ENS Lyon)
    Vendredi 15 juin 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Interrupteur optique, ondes gravitationnelles et physique statistique hors d'équilibre : des microleviers à tout faire
    Dans cette présentation, je montrerai comment le bruit thermique, loin d'être une simple nuisance, peut être un outil de précision dans l'exploration des matériaux autant qu'une porte ouverte sur des phénomènes de physique statistique intrigants. Guidée par la sérendipité, cette marche aléatoire de la physique à l'échelle (...)
  • Séminaire PMMH : Thomas Engels (LMD, ENS)
    Vendredi 8 juin 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    The impact of turbulence on flying insects in tethered and free flight : high-resolution numerical experiments
    Flapping insects are remarkably agile fliers, adapted to a highly turbulent environment. We present a series of high resolution numerical simulations of a bumblebee interacting with fully developed turbulent inflow. We consider both tethered and free flight, the latter with all six degrees of freedom coupled to (...)
  • Séminaire PMMH - John Kolinski (EPFL)
    Vendredi 1er juin 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Wetting and contact line propagation on solid surfaces
    John M. Kolinski, EMSI, EPFL, Lausanne Switzerland The propagation of a contact line at the interface between liquid and a dry solid is of great fundamental and practical importance. We experimentally probe the dynamics of wetting that occur when an impacting drop first contacts a dry surface. We show that the (...)
  • Séminaire PMMH - Alba Marcellan (SIMM, ESPCI)
    Vendredi 25 mai 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Some strategies for hydrogel toughening, from polymer adsorption onto NPs to responsive toughening by phase-separation
    Based on gel's remarkable features of absorption, storage or release of water (or solvent), gels have become essential in engineering applications like superabsorbent, soilless agriculture or tissue engineering and regeneration. Gels could also be key players for the design of flexible actuators, valves or (...)
  • Séminaire PMMH - Aleksandra Walczak (ENS - LPT)
    Vendredi 18 mai 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Learning how bird flocks coordinate
    Flocking is a typical example of emergent collective behavior, where interactions between individuals produce collective patterns on large scales. I will discuss how by analysing different aspect of this motion based on quantitative data we can learn about the origins of these interactions. Specifically I will (...)
  • Séminaire PMMH - Giuseppe Zurlo (National University of Ireland)
    Vendredi 13 avril 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Manufacturing of information-rich elastic bodies through surface deposition.
    In this talk I will discuss a recent theory, developed in collaboration with Lev Truskinovsky, that describes how desired distributions of residual stress can be achieved in bodies that are manufactured though the local addition of mass on their boundary [1],[2]. The source of residual stresses in elastic bodies (...)
  • Séminaire PMMH - Etienne Guyon
    Vendredi 6 avril 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Une brève histoire des musées de sciences jusqu'au Palais de la Découverte aujourd'hui et demain (?)
    Au-delà de la diversité des conditions de leurs créations et de leurs fonctionnements dans l'histoire, on retrouve dans l'histoire des Musées des composantes universelles. Tout en faisant références à d'autres expériences culturelles scientifiques, nous axerons notre présentation sur quatre grands musées français. Tout (...)
  • Séminaire Charlotte K. Hemelrijk (Univ. Groningen)
    Mercredi 4 avril 2018 de 11h00 à 12h00 - Salle réunion PMMH 2
    
  • Séminaire PMMH - Leonardo Gordillo (Universidad De Santiago de Chile)
    Vendredi 30 mars 2018 de 11h00 à 12h00 - Salle réunion PMMH 1
    Drop-impact dynamics on solid surfaces : Evolution of impact force
    In this talk, I will give an overview of our latest advances in understanding the dynamics of drop impacts on dry solid surfaces. By synchronizing high-speed photography with fast force sensing, we simultaneously measured the temporal evolution of the shape and impact force of impacting drops over a wide range of (...)
  • Séminaire PMMH - Falko Ziebert (Universität Heidelberg)
    Vendredi 9 mars 2018 de 11h00 à 12h00 - A1 (Urbain)
    Self-propelled motion of biological cells and polymeric fibers
    Self-propulsion, i.e. self-organized motion in the absence of external forces, is an active research topic in non-equilibrium physics. Depending on the system, open questions span from the propulsive force generation and transfer over guiding mechanisms to collective effects in ensembles of self-propellers. The (...)
  • Séminaire PMMH - Sébastien Neukirch (Institut d'Alembert, Sorbonne Université)
    Vendredi 16 février 2018 de 11h00 à 12h00 - A1 (Urbain)
    Le treuil élastocapillaire en une et deux dimensions
    Nous parlerons d'élasto-capillarité, domaine mêlant la déformation des structures élastiques et les forces de tension de surface. En effet, les forces capillaires que développent les gouttes liquides peuvent être suffisamment intenses pour plier des filaments ou des membranes, voire même enrouler des fibres. Plus (...)
  • Séminaire laboratoire PMMH - José Eduardo Wesfreid
    Vendredi 9 février 2018 de 11h00 à 12h00 - A1 (Urbain)
    Henri BENARD : convection thermique et tourbillons derrière un obstacle
    Henri Bénard, physicien français né en 1874 et décédé en 1939, a été le précurseur des études expérimentales systématiques de deux sujets majeurs de la mécanique des fluides : la convection thermique des fluides chauffés par le bas (convection de Rayleigh-Bénard et de Bénard-Marangoni) et du lâché tourbillonaire derrière un (...)
  • Séminaire PMMH - Matthieu Roché (MSC, Univ. Paris Diderot)
    Vendredi 2 février 2018 de 11h00 à 12h00 - A1 (Urbain)
    Effet Marangoni induit par des tensioactifs solubles
    La présence d'un gradient thermique ou d'un gradient de concentration de surface en molécules tensioactives le long d'une interface entre deux liquides conduit à l'existence d'un gradient de tension interfaciale et à l'établissement d'un écoulement dans le volume de chaque liquide : c'est l'effet Marangoni, thermique (...)
  • Séminaire laboratoire PMMH Alexandre NICOLAS (LPTMS - Psud)
    Vendredi 19 janvier 2018 de 11h00 à 12h00 - A3 (Joliot)
    Écoulements particulaires en géométrie confinée et au passage d'une constriction : De la microfluidique aux lâchers de taureaux
    Si l'on force des particules discrètes à s'écouler dans un canal étroit ou à travers une constriction, des effets assez surprenants peuvent se produire. J'aborderai quelques exemples de tels écoulements. Dans le domaine de la microfluidique, la mise au point de laboratoires sur puce demande de transporter des émulsions (...)

• 2017

  • Séminaire PMMH : Jean-Pierre Hulin (FAST, Orsay)
    Vendredi 22 décembre 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Tracer spreading at low Reynolds numbers : reversible or not ?
    The reversibility of fluid velocity fields at low Reynolds numbers with respect to a change of the flow direction is well established : its may result in the reversibility of tracer spreading and mixing as may be demonstrated spectacularly in simple geometries such as Couette flows. However, at long times, this (...)
  • Séminaire PMMH - Hiroaki Katsuragi (Nagoya University)
    Vendredi 15 décembre 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Solid projectile impact onto a porous dust aggregate consisting of micrometer-sized particles
    Porous dust aggregates consisting cohesive monomer grains are considered materials to build planetesimals in a protoplanetary disk. In order to reveal the history of planet formation, mechanical properties of dust aggregates have to be quantitatively understood. In this study, we perform a simple impact experiment (...)
  • Séminaire PMMH - Frédéric Moisy (Laboratoire FAST - Université Paris Sud
    Vendredi 24 novembre 2017 de 11h00 à 12h15 - A3 (Joliot)
    Anti-rotation dans un verre de bière ou une tasse de café
    Pour aérer un vin avant de le déguster, on imprime au verre un mouvement de translation circulaire. En plus de créer une onde de surface se propageant circulairement (onde de ballottement, ou sloshing), il est bien connu que ce mouvement engendre une rotation du fluide, dans la même direction que la vitesse de phase (...)
  • Séminaire PMMH - Gergely Molnár (Laboratory 3SR, Univ. Grenoble Alpes)
    Vendredi 17 novembre 2017 de 11h00 à 12h00 - Bureau d'étude
    Multiscale methods for the analysis of plastic deformation of amorphous materials
    Silicate glasses are used for many technical purposes, especially where stiffness and transparency are required. These glasses are brittle on the macroscopic scale but ductile at the micron level. The study deals with the analysis of the elasto-plastic response of sodium silicate glasses. We propose a new method (...)
  • Séminaire PMMH - Wilson Poon (The University of Edinburgh, UK)
    Vendredi 20 octobre 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Complexity and decay — towards a science of self disassembly
    Soft matter physics has been obsessed with 'self assembly' for some time - the ability of Brownian or, more recently, 'active matter' systems to generate (sometimes useful !) patterns 'on their own accord'. The original impulse for this was biological, the term 'self assembly' being first used in a famous 1962 (...)
  • Séminaire PMMH - Kirsten Martens (LIPhy, Univ. Grenoble Alpes)
    Vendredi 6 octobre 2017 de 11h00 à 12h30 - A1 (Urbain)
    Fluidization of yield stress materials through active and activated local events
    In this talk I will discuss the possible fluidization mecanisms of yield stress materials through either locally active dynamics, like cell division in tissues [1,2] or vibration induced local plasticity like in externally driven granular materials [3]. The long range elastic response to these events lead to a (...)
  • Séminaire PMMH : Timothée Mouterde (LPS, ENS))
    Vendredi 29 septembre 2017 de 11h00 à 12h00 - A1 (Urbain)
    Matériaux multifonctions : antipluie, antibuée, antireflets
    Sur une surface couverte de microrugosités hydrophobes, l'eau est ultra-mobile. Ces surfaces sont appelées superhydrophobes : les rugosités retiennent une couche d'air sous la goutte qui repose donc sur coussin d'air. En situations humides, la buée dans les textures peut altérer ces propriétés anti-eau. Comme le (...)
  • Séminaire PMMH : Alexis Duchesne
    Vendredi 22 septembre 2017 de 10h30 à 12h30 - A1 (Urbain)
    La marche des Funam-bulles : promenades de bulles sur un fil chaud dans un bain liquide.
    Lorsque l'on chauffe un fil résistif horizontal dans un bain liquide et que l'on dépasse localement la température d'ébullition dudit liquide, des bulles de vapeur vont nucléer à la surface du fil. Les différentes théories présentes dans la littérature prédisent que les bulles générées depuis des sites de nucléation actifs (...)
  • Séminaire PMMH - Antonin Coutant (Univ. of Nottingham)
    Vendredi 15 septembre 2017 de 11h00 à 12h00 - Bureau d'Etudes
    A black hole in your bathtub
    I will discuss the possibility to mimic black hole physics in fluid flows. The starting point is an analogy discovered by Unruh between the propagation of sound in a flowing fluid and waves around a black hole. In these analogue setups, it is possible to test various black hole effects. I will focus on the case (...)
  • Séminaire PMMH : Pascal Raux
    Vendredi 8 septembre 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Interactions entre grains et liquides
    Dans cette présentation, je propose d'illustrer la diversité des interactions entre grains et liquide au travers de différents problèmes : – L'ajout de liquide accroit la cohésion du milieu granulaire. Contrairement aux régimes où le liquide est en faible quantité, la transition vers un milieu granulaire saturé a reçu (...)
  • Séminaire PMMH - Alfred J. Crosby (Univ. of Massachusetts Amherst)
    Vendredi 21 juillet 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Deformation Mechanisms in Ultra-thin Polymer Glasses
    The properties of polymer glasses have been studied classically due to their importance for a wide range of technologies ; however, there is increasing need and demand to use these materials in geometries where dimensions approach the length scale of an individual polymer chain. Although significant efforts over (...)
  • Séminaire PMMH - Pierre Rognon (Univ. of Sydney)
    Vendredi 30 juin 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Rheology and mixing properties of dense granular flows
    Pierre Rognon, Particles and Grains Laboratory School of Civil Engineering- The University of Sydney, Sydney Australia Granular materials like sand, rice and snow are composed of many grains interacting with each other. Predicting their ability to flow and to mix is key to a number of applications in geophysics, (...)
  • Séminaire PMMH - Philip Marcus (University of California, Berkeley)
    Vendredi 23 juin 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Optimal Design by Morphing : Is the Navier-Stokes Equation the Best Method for Describing Fluid Dynamics ?
    We present a new method, which we call design-by-morphing, for the optimal hydrodynamic or aerodynamic design of the shape of an object. Traditional morphing methods, which require covering the surface of an object with a large number (typically millions) of triangular meshed points, cannot be used in searches for (...)
  • Séminaire PMMH - Rémy Dubertrand (Univ de Liège)
    Vendredi 16 juin 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Scattering theory for walking droplets in the presence of obstacles
    Walking droplets that are sustained on the surface of a vibrating liquid, have attracted considerable attention during the past decade due to their remarkable analogy with quantum wave-particle duality. This was initiated by the pioneering experiment by Y. Couder and E. Fort in 2006, which reported the observation (...)
  • Séminaire PMMH - M. Andreatta (CNRS/IRCAM/UPMC et Université de Strasbourg / USIAS)
    Vendredi 9 juin 2017 de 10h30 à 12h30 - A1 (Urbain)
    Algèbre et géométrie en musique et musicologie
    Si les mathématiques ont accompagné depuis toujours la réflexion sur les fondements théoriques de la musique, elles sont devenues incontournables dans l'analyse musicale, en particulier à l'aide de l'ordinateur. Dans cette présentation, on montrera quelques aspects logiques et géométriques à l'œuvre dans la musique (...)
  • Séminaire PMMH : Marcelo Dias (James Madison University)
    Vendredi 2 juin 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Thin Elastic Structures : A roadmap from forms to functions
    Thin elastic structures (e.g. plates and shells) have stimulated new approaches and applications to mechanical metamaterials as well as brought to light many fundamental questions in our understanding of shape and function. Insights of what functionality roles these structures play comes from connections between (...)
  • Séminaire PMMH - Eric Dufresne (ETH, Zurich)
    Vendredi 19 mai 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Three-Phase Contacts with Soft Solid Substrates
    Surface forces can drive large deformations of soft solids. I will discuss the deformation of soft solids in contact with liquid droplets and rigid particles. Here, classic results for wetting and adhesion fail to describe the equilibrium of three-phase contact lines. While interfacial energies are sufficient to (...)
  • Séminaire PMMH - Jacques Treiner (Sciences-Po)
    Vendredi 12 mai 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Un regard critique sur les scénarios 100% renouvelables
    Résumé : Plusieurs organismes ont récemment proposé pour la France une perspective de fourniture d'énergie à la fois décarbonée et sans faire appel à la filière nucléaire. L'ADEME, en se limitant à l'électricité, propose un mix de ce type pour 2050 à un coût voisin du coût correspondant à une prolongation du mix d'aujourd'hui, (...)
  • Journées du laboratoire PMMH hors murs
    Vendredi 5 mai 2017 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Séminaire PMMH - Corrado Rainone (Weizmann Institute, Israel)
    Vendredi 28 avril 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Shear bands as manifestation of a criticality in yielding amorphous solids.
    The nature of the yielding transition in amorphous solids is a long-standing riddle which has attracted a lot of research effort in recent years. Recently, some of us have proposed a picture of yielding as a first-order like transition in a suitable overlap order parameter, measuring the degree of similarity (...)
  • Séminaire PMMH - Matteo Ciccotti (SIMM, ESPCI)
    Vendredi 21 avril 2017 de 11h00 à 12h00 - Bureau d'Etudes
    MICROMECHANISMS OF FRACTURE PROPAGATION IN GLASSY POLYMERS
    While most glassy polymers are nominally brittle at macroscopic scales, they are known to exhibit plastic deformation in indentation, scratching, and microcutting when the loaded region is sufficiently small. The same applies to the micrometer size process zone at the tip of a propagating crack. While the presence (...)
  • Séminaire PMMH - Alexandre Danescu (EC, Lyon)
    Vendredi 31 mars 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Design of three-dimensional objects using stress relaxation in thin films : the interplay between mechanics and geometry
    It is well-known that a free pre-stressed elastic bi-layer will deform so as to "relax" its total energy. The relaxation process may deform simple straight segments to rolls, or curls, etc. In an attempt to cover more complex three-dimensional geometries we address and solve the general question concerning the (...)
  • Séminaire PMMH - Antonio de Simone (SISSA, Trieste, Italy)
    Vendredi 24 mars 2017 de 11h00 à 12h00 - Bureau d'Etudes
    On shape control : some case studies inspired by biological and bio-inspired locomotion at small scales
    Control of shape is at the root of many processes of fundamental relevance in Biology, from morphogenesis to locomotion. For slender one-dimensional objects (rods) or thin two-dimensional ones (plates and shells), shape can be controlled by adjusting curvature thanks to the application of active internal (...)
  • Séminaire PMMH - Alexandre Le Tiec (LUTH, Observatoire de Paris)
    Vendredi 17 mars 2017 de 11h00 à 12h00 - Bureau d'Etudes
    General Relativity and Gravitational Waves, 100 years after Einstein
    A century ago, Albert Einstein revolutionized our understanding of the nature of space, time and gravitation. His general theory of relativity predicts, in particular, the existence of black holes and gravitational waves. By sheer coincidence, the celebration of general relativity's centennial also marked the (...)
  • Séminaire PMMH - Henri Van Damme (ESPCI-MIT)
    Vendredi 10 mars 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Gaz et huile de « schiste » : un bon sujet, quoiqu'il advienne ?
    Les réservoirs pétroliers auto-sourcés sont des roches compactes riches en matière organique qui sont exploités comme source de gaz naturel et/ou de pétrole dits « non conventionnels ». Ils tirent leur qualificatif « auto-sourcés » du fait que les hydrocarbures qu'ils contiennent ont été générés sur place et ont échappé à la (...)
  • Séminaire PMMH - Patrick Guenoun (CEA)
    Vendredi 3 mars 2017 de 11h00 à 12h00 - A4 (Langevin)
    Elasticity of nano structured objects probed by AFM
    In this communication we will describe how Atomic Force Microscopy (AFM) was used to investigate the mechanical properties of nanostructured objects. These objects are nanocapsules designed for a theranostic approach where they can provide both acoustic imaging properties in vivo and release properties of (...)
  • Séminaire PMMH - Camille Duprat (LadHyX)
    Vendredi 24 février 2017 de 11h00 à 12h00 - A4 (Langevin)
    Catching drops with fibers
    In this talk, I will present recent results on the capture of aerosol droplets with a textile, i.e. a fibrous material. Fibrous media are commonly used to collect droplets from an aerosol ; woven nets are used to harvest fresh water from fog, and non-woven entangled fibers are used to filter oil drops from gas (...)
  • Séminaire PMMH - AIMEE K. WESSEL (INSTITUT PASTEUR)
    Vendredi 3 février 2017 de 11h00 à 12h00 - A4 (Langevin)
    Examining prokaryotic community behavior using 3D printing
    Bacterial communities engage in social activities, exhibiting behaviors such as communicating with small signaling molecules (quorum sensing [QS]) and building antibiotic-resistant biofilms. Most of our understanding of QS and biofilm formation arises from in vitro studies of bacterial communities containing large (...)
  • Séminaire PMMH - Daniel Bonamy (CEA-SACLAY)
    Vendredi 20 janvier 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Sismicité en rupture hétérogène nominalement fragile : organisation statistique des événements acoustiques accompagnant la propagation lente d'une fissure unique
    Prévoir quand un matériau fragile va se rompre n'est pas une mince affaire ! Le comportement en rupture observé à l'échelle macroscopique est en effet très sensible aux inhomogénéités de structure à des échelles très fines, à la présence de défauts ou d'imperfections. Cela se traduit par des fluctuations statistiques importantes (...)
  • Séminaire PMMH - Pierre-Yves Passaggia (Univ. of North Carolina)
    Vendredi 13 janvier 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Convection horizontale : stabilité, bifurcation et son rôle dans la circulation méridionale des océans.
    Le rôle des différents phénomènes physiques responsables de la circulation méridionale des océans reste une question ouverte. Afin de comprendre l'impact du différentiel de température entre les pôles et l'équateur à la surface des océans sur cette circulation, un modèle d'écoulement dans une cavité, chauffée et refroidie à (...)
  • Séminaire PMMH - Fréderic Lechenault - LPS (ENS Paris)
    Vendredi 6 janvier 2017 de 11h00 à 12h00 - Bureau d'Etudes
    Origami mechanics and multistability
    Over the past thirty years, the ancient art of paper folding, or origami, has evolved into an interdisciplinary scientific field. Origami offers the possibility for new metamaterials whose overall mechanical properties can be programmed by acting locally on each crease. In particular, origami metamaterials (...)

• 2016

  • Séminaire PMMH - Suzie Protière (Institut d'Alembert, UPMC)
    Vendredi 16 décembre 2016 de 11h00 à 12h00 - A1 (Urbain)
    The instabilities of a granular raft
    Small objects trapped at an interface are very common in Nature (waterstriders, ant rafts, bubbles or pollen, membranes…). They also find an application in industrial processes since they can act as stabilizing agents for emulsions or foams. Their study is therefore of practical as well as fundamental importance. (...)
  • Séminaire PMMH - John Brady (CalTech)
    Vendredi 9 décembre 2016 de 11h00 à 12h00 - A1 (Urbain)
    Forces, Stresses and the (Thermo ?)dynamics of Active Matter
    A distinguishing feature of many living systems is their ability to move - to be active. Through their motion living systems are able to self-assemble : birds flock, fish school, bacteria swarm, etc. But such behavior is not limited to living systems. Recent advances in colloid chemistry have led to the (...)
  • Séminaire PMMH - Stéphane Popinet (Institut d'Alembert)
    Vendredi 2 décembre 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Adaptive numerical methods for fluid mechanics
    The equations of fluid mechanics can be used to describe natural processes over a wide range of scales, from the behaviour of micro-organisms to astrophysics. Each of these processes is in turn often controlled by internal interactions on widely different scales. Numerical methods able to efficiently resolve these (...)
  • Séminaire PMMH - Hamid Kellay (LOMA, Université de Bordeaux)
    Vendredi 25 novembre 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Hydrodynamics experiments using soap films and soap bubbles
    I will describe experiments using soap films and soap bubbles to illustrate the interest of these common objects to some fluid mechanics problems. The flow in the very thin layer of these films is basically two dimensional and this property brings fundamental differences with fluid flows in three dimensions as (...)
  • Séminaire PMMH - Maximilien Levesque (ENS, Paris)
    Vendredi 18 novembre 2016 de 11h00 à 12h00 - Bureau d'Etudes
    The one molecule in a sea of others : tackling solvation at the molecular scale
    by Maximilien Levesque, laboratoire PASTEUR, Ecole Normale Supérieure Physical and chemical processes in the liquid and gas phases happen in an embedding medium, a large number of solvent molecules, for instance water, that crowd the environment. To take into account this environment at the molecular scale, (...)
  • Séminaire PMMH - Etienne Barthel (SIMM, ESPCI)
    Vendredi 4 novembre 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Telephone Cords, parrot ladders, hexagons and the like - the unexpected morphologies of thin film buckles
    Thin films with large compressive residual stresses and low adhesion are prone to buckling and delamination. This is both a significant technical issue, with relevance to thin film stability, and an interesting academic problem where (non-linear) plate mechanics couples to mixed mode adhesion. This coupling (...)
  • Séminaire PMMH - Chinar Rana (ULB, Bruxelles)
    Vendredi 21 octobre 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Effects of adsorption and viscous fingering instability on the dispersion and the form of the peaks in liquid chromatography
    Liquid chromatography is a flow based separation method where, a given fluid (called eluent) displaces a miscible sample consisting of a solvent in which a mixture of solutes (also named analytes) is dissolved. The analytes are separated during the displacement because of the selective adsorption on the porous (...)
  • Séminaire PMMH - Brigitte Senut (Muséum National d'Histoire Naturelle)
    Vendredi 7 octobre 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Des grands singes et des hommes : une histoire dans les arbres
    À la lueur des découvertes récentes africaines, nous pouvons mieux appréhender nos origines ; mais ces dernières sont-elles vraiment africaines ? Sous quelles conditions climatiques l'émergence des grands singes modernes et des premiers hominidés peut-elle être envisagée ? Si on a souvent considéré la savane sèche comme un (...)
  • Séminaire PMMH - Tamas Borzsonyi (Wigner Research Center for Physics, Budapest)
    Vendredi 30 septembre 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Rotation and ordering of elongated particles under shear
    Ordering and alignment of elongated objects in shear flows can be observed at all length scales, in log jams on rivers, in seeds, nanorods, viruses, and even at molecular scales in nematic liquid crystals. We show, that for dry granular materials in steady shear flow the time and ensemble averaged direction of the (...)
  • Séminaire PMMH : Sébastien Candel (EM2C, Centrale Paris / Académie des sciences)
    Vendredi 23 septembre 2016 de 11h00 à 12h30 - A4 (Langevin)
    La complexité de la combustion et comment la gérer
    La combustion est une des sources de la civilisation. Son rôle actuel est considérable puisqu'elle fournit aujourd'hui 85% de l'énergie primaire consommée dans le monde. L'homme maîtrise le feu depuis un demi-million d'années mais la science de la combustion est bien plus récente. On propose dans ce séminaire un panorama (...)
  • Séminaire PMMH - Marino Arroyo (UPC)
    Vendredi 8 juillet 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Reverse engineering the motility of euglena cells : shape transformations and the interaction with the environment
    Euglenids are unicellular aquatic organisms capable of moving either by beating a flagellum or by executing dramatic and harmonious shape changes, whose function still remains unclear. These shape changes are accomplished thanks to a complex structure underlying the plasma membrane, made of interlocking (...)
  • Séminaire PMMH - Mónica S. N. Oliveira (Univ. of Strathclyde)
    Vendredi 1er juillet 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Extension dominated flows at the microscale : from instabilities to optimisation
    James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ, United Kingdom The use of microfluidic devices has found applications in a range of different areas, many of which make use of complex fluids, such as biofluids and polymer solutions that (...)
  • Séminaire PMMH - Scott Waitukaitis (Univ. Leiden)
    Vendredi 24 juin 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Rabbits, Planets, Volcanoes, Dust Devils : The Surprising Physics of Granular Tribocharging
    If you shuffle your feet across a carpet and touch a doorknob, you might get shocked. This is tribocharging—the transfer of electrical charge between different materials. Although it was observed as early as 600 B.C. in ancient Greece, we know surprisingly little about it. One of the most perplexing observations (...)
  • Séminaire PMMH - Alberto Fernandez-Nieves (Georgia Tech)
    Vendredi 17 juin 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Active nematics on tori
    We will discuss recent results with active nematics on toroidal surfaces. We will start by briefly discussing how we make toroidal droplets, how these evolve in time, and how we stabilize the toroidal shape. We will then address how nematic liquid crystals organize on the surface of stable tori. Despite no defects (...)
  • Séminaire PMMH - Carine Douarche (LPS, Univ. Paris-Sud)
    Vendredi 10 juin 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Bacteria self-assemblies lead to hydrodynamic instabilities
    The mechanisms of the bacterial motility and chemotaxis are now quite well known at the single cell level ; however the way a whole cell population moves at a macroscopic scale still raises some fundamental questions. The study of the behavior of a population of Escherichia coli in oxygen gradients in the bulk of (...)
  • Séminaire PMMH - Roland Winkler (Forschungszentrum Jülich)
    Vendredi 3 juin 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Microswimmer : From swimming bacteria to collective behaviors of active Brownian particles
    Locomotion is a major achievement of biological evolution. Microorganisms, such as bacteria, algae, and sperm cells are equipped with flagella and are able to exploit drag for their propulsion. Two prominent swimming mechanisms are rotating helical flagella, exploited by many bacteria, and snake-like or whip-like (...)
  • Séminaire PMMH - Philippe Marmottant (LIPhy, Grenoble)
    Vendredi 27 mai 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Cavitation of sap in trees and leaves
    In this talk, we will present our investigations on the nucleation of bubbles in tree vessels, by showing experiments on wood and on leaves. Such explosive bubbles occur by cavitation, since the liquid sap in trees is under extreme negative pressure. They form an emboly that can develop and affect the hydraulic (...)
  • Séminaire PMMH - Ryan Hayward (U. Mass. Amherst)
    Vendredi 20 mai 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Folding gels and shells : Origami-based design of reconfigurable 3D structures and ‘mechanical meta-materials'
    Centuries of artistic tradition, coupled with recent advances in the mathematics and mechanics of folded structures, have made origami a powerful method for the design of materials with reconfigurable shapes and tailored mechanical properties. Inspired by these possibilities, our group has studied the design and (...)
  • Séminaire PMMH - Frédéric Restagno (LPS, Univ. Paris-Sud)
    Vendredi 13 mai 2016 de 11h00 à 12h00 - Bureau d'Etudes
    FRICTION AT MICRO AND MACRO-SCALE
    Friction is a common phenomenon that occurs when to objects are force to move tangentially relatively to each other. During this seminar, we shall present two series of experiments concerning friction at macro and micro-scale. In a first set of experiment [1], we will study the aptitude of surface with anchored (...)
  • Séminaire PMMH - Pawel Pieranski (LPS, Orsay)
    Vendredi 15 avril 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Cunéitropisme et les défauts de la texture furcelle
    Après une introduction large aux cristaux liquides, nous montrerons comment générer de façon reproductible la texture pseudo-planaire [1] (voir fig. a) et nous verrons que dans certaines conditions sa durée de vie peut être pratiquement infinie. La propriété la plus saillante de cette version immortelle de la texture (...)
  • Séminaire PMMH - Joseph Paulsen (Syracuse University)
    Vendredi 8 avril 2016 de 11h00 à 12h00 - Bureau d'Etudes
    The wavelength of wrinkles in elastic sheets on curved topographies
    A thin elastic sheet will buckle when it is compressed, leading to the familiar wrinkle patterns on our foreheads, on plastic-wrapped objects, and on crinkly leaves. Wrinkling has recently been used as a noninvasive probe of thin film properties and mechanical environment. However, the current understanding of (...)
  • Séminaire PMMH - Anaël Lemaître (Laboratoire Navier, ENPC)
    Vendredi 1er avril 2016 de 11h00 à 12h00 - A1 (Urbain)
    Structural relaxation is a scale-free process
    Structural relaxation is the process via which a liquid explores its equilibrium ensemble. It is responsible for the dramatic slowing down at the glass transition, and has thus received a quite considerable amount of attention. Yet, the mechanisms governing relaxation are still largely unknown. We will (...)
  • Séminaire PMMH - Catherine Quiminal, Paul Schor (Université Paris Diderot)
    Vendredi 25 mars 2016 de 11h00 à 12h00 - A1 (Urbain)
    Politiques migratoires et parcours de migrants
    – Il s'agit dans ce bref exposé de mettre en regard les politiques migratoires, les politiques réglementant la circulation des gens, les catégories qu'elles produisent, véhiculent sur lesquelles elles s'appuient avec le parcours de migrants à travers des figures types ou réelles, stylisées de migrants d'Afrique (...)
  • Séminaire PMMH - Romain Ricciotti (Agence Lamoureux & Ricciotti Ingénierie)
    Vendredi 18 mars 2016 de 11h00 à 12h00 - A1 (Urbain)
    De nouveaux ouvrages d'art en nouveaux bétons
    Romain Ricciotti nous invite à une visite guidée technique de quelques-uns de chefs-d'oeuvres architecturaux récents qu'il a conçus grâce à l'utilisation de nouveaux bétons, en particulier avec son père, l'architecte Rudy Ricciotti (qui sera présent au séminaire) : – Mucem à Marseille et sa structure externe en poteaux (...)
  • Séminaire PMMH - Lydéric Bocquet (LPS, ENS)
    Vendredi 11 mars 2016 de 11h00 à 12h00 - A2 (Schutzenberger)
    Osmotic flows, from nanoscales to kidney filtration
    Osmosis describes the flow of water across semipermeable membranes powered by the chemical free energy contained in salinity gradients. It is a fundamental transport process for water in all living systems, and its applications are countless. While osmosis can be expressed fundamentally in simple terms via the (...)
  • Séminaire du PMMH : Constantino Tsallis (CBPF, Brésil)
    Vendredi 4 mars 2016 de 11h00 à 12h00 - Bureau d'Etudes
    On the foundations of statistical mechanics : Concepts and applications
    Whenever basic hypothesis such as ergodicity are not satisfied, the Boltzmann-Gibbs statistical mechanics, based on the additive Boltzmann-Gibbs entropy, can yield results that are not confirmed by experiments. A more general theory, namely nonextensive statistical mechanics, based on nonadditive entropies, (...)
  • Séminaire PMMH - Laurent Chevillard (ENS-Lyon)
    Vendredi 19 février 2016 de 11h00 à 12h00 - A4 (Langevin)
    Une peinture aléatoire de la turbulence des fluides
    Dans une première partie de cet exposé, je rappellerai quelques propriétés universelles de la turbulence des fluides observées dans les expériences et simulations numériques des écoulements homogènes et isotropes. J'insisterai sur la statistique des fluctuations de la vitesse, aussi bien dans un cadre spatial (description (...)
  • Séminaire PMMH - Arnold Mathijssen & Andreas Zöttl (University of Oxford)
    Vendredi 12 février 2016 de 11h00 à 12h00 - Amphi Langevin
    Hydrodynamics and noise in confined microswimmer suspensions
    Active particles and biological microswimmers such as bacteria or sperm cells moving in their natural environment are continually subjected to fluid flow and confining surfaces. To understand the underlying basic physical mechanisms in these environments their locomotion in microfluidic channels is nowadays widely (...)
  • Clément Sire (LPT, Université Paul Sabatier, Toulouse)
    Vendredi 5 février 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Phase diagram of a data-driven fish school model
    After some generalities concerning "intelligent" active matter ("social" vs physical "forces", effect of anisotropic sensorial stimuli, additivity of "forces"...), and in particular fish schools, I will present a series of experiments performed in Guy Theraulaz' group at the CRCA in Toulouse, and a class of models (...)
  • Journées de Physique Statistique 28 et 29 Janvier 2016
    Vendredi 29 janvier 2016 de 09h00 à 18h00 - Amphi Langevin
    
  • Séminaire PMMH - Adama Creppy (FAST)
    Vendredi 22 janvier 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Etude de la dynamique collective de spermatozoïdes
    Les micro-organismes présentent des comportements collectifs qui émergent des interactions qui se produisent à l'échelle individuelle. Dans le cas des suspensions concentrées (fraction volumique > 50 %) les effets stériques deviennent dominants. C'est le cas du liquide séminal de bélier sur lequel cette étude a (...)
  • Séminaire PMMH - Julien Derr (MSC)
    Vendredi 15 janvier 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Morphogenesis and Motions in Biological Systems
    The constraints of the environment always plays a determinant role in the development of biological systems and dynamical aspects are also important. That's why we have been investigating the link between morphogenesis in biological systems and their associated motions. We distinguish two types of motions. First, (...)
  • Séminaire PMMH - Antoine Naert (ENS Lyon)
    Vendredi 8 janvier 2016 de 11h00 à 12h00 - Bureau d'Etudes
    Expériences de physique statistique dans les gaz granulaires
    Un gaz granulaire peut être considéré comme le paradigme d'un thermostat dissipatif. En d'autres termes, lui donner ou lui prendre une petite quantité d'énergie ne change pas son état macroscopique stationnaire. Bien sûr, il est nécessaire de donner au gaz granulaire une puissance mécanique pour compenser la dissipation (...)

• 2015

  • Fabian Brau (Université Libre de Bruxelles)
    Vendredi 18 décembre 2015 de 11h00 à 12h00 - Amphi Urbain (A1)
    Patterns dans les plaques minces élastiques
    De nombreux types de motifs émergeant spontanément peuvent être observés dans des systèmes impliquant des plaques mince élastiques et soumis à des contraintes externes ou internes (compression ou croissance différentielle, cisaillement, déchirure, etc.). Ces systèmes mécaniques peuvent parfois être vus comme des (...)
  • Séminaire PMMH - Christophe Eloy (IRPHE, Marseille)
    Vendredi 11 décembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Auto-similarité et architecture des arbres
    La partie aérienne d'un arbre peut être vue comme la réponse biologique au problème d'ingénierie suivant : réaliser une structure mécaniquement stable, la plus légère possible et permettant un accès maximal à la lumière. Pour répondre à ce cahier des charges, l'arbre croît, en produisant à chaque étape de sa croissance des (...)
  • Michaël Benzaquen (PCT, Gulliver, ESPCI)
    Vendredi 4 décembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Waves and wakes at different scales
    Simply by looking at a duck swimming in a pond or a cargo ship moving on a calm sea, one can clearly tell that there is something common about their wake. Indeed, they both display a familiar V-shaped pattern which only differ from one another by their dimensions. In 1887, Lord Kelvin was able to provide a theory (...)
  • Oliver Bäumchen (MPI for Dynamics and Self-Organization, Göttingen)
    Vendredi 27 novembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Sushant Anand (MIT)
    Vendredi 20 novembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Megan T. Valentine (UCSB)
    Vendredi 13 novembre 2015 de 11h00 à 12h00 - Amphi Langevin
    Learning from nature : how mussels stick to rocks, and what it can teach us about material design
    Mussels permanently adhere to surfaces through a circular plaque that is attached to the animal body via a long thin thread ; forming a mushroom-shaped geometry. A plaque just a few millimeters in diameter with a 250-micron diameter thread can withstand large pull forces of a several Newtons without debonding. (...)
  • Joshua McGraw (ENS)
    Vendredi 6 novembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Sans titre
    Vendredi 23 octobre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Teo Burghelea (CNRS, Laboratoire de Thermocinétique de Nantes)
    Vendredi 16 octobre 2015 de 11h00 à 12h00 - Amphi Urbain
    Rheological properties and microscopic flows of suspensions of the non-motile green micro-alga Chlorella Vulgaris
    In the first part of the talk I will present a systematic study of the rheological properties of solutions of non-motile micro-algae (Chlorella vulgaris CCAP 211-19) in a wide range of volume fractions is presented. As the volume fraction is gradually increased, several rheological regimes are observed. At low (...)
  • Fête de la Science
    Vendredi 9 octobre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Alexandre Darmon (EC2M, Gulliver, ESPCI)
    Vendredi 2 octobre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Waltzing defects in cholesteric liquid crystal shells : interplay between topology and elasticity
    Confining rod-like molecules, such as nematogens of liquid crystals, on a curved surface inevitably yields topological defects, which are singular points where the alignment between molecules can no longer be fulfilled. Remarkably, in the specific case of a nematic sphere, Poincaré stated that the sum of the (...)
  • Agnese Seminara (LPMC, Université de Nice)
    Vendredi 25 septembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Olfactory navigation in mice
    The ability to shift between multiple decision-making strategies during natural behavior allows animals to strike a balance between flexibility and efficiency. We investigated odor-guided navigation by mice to understand how decision making strategies are balanced during a complex natural behavior. Mice navigated (...)
  • Etienne Couturier (MSC)
    Vendredi 18 septembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Deux problèmes des coques minces provenant de cellules avec paroi :
    – Déformation isométrique du grain de pollen D. Caerula
    – Croissance et division de S. Pombe
    Les coques des grains de pollen peuvent s'ouvrir et se refermer de manière passive pour protéger le contenu cellulaire de la dessiccation. Pour comprendre les adaptations géométriques très élégante du grain de pollen de D. Caerula, nous l'avons modélisée par une coque mince sphérique munie d'une ouverture à symétrie de (...)
  • Anne-Laure Biance (ILM, Lyon)
    Vendredi 11 septembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Pascal Hémon (LadHyX, École Polytechnique)
    Vendredi 4 septembre 2015 de 11h00 à 12h00 - Bureau d'Etudes
    La simulation du vent sur les constructions : l'exemple de la Fondation Louis Vuitton
    Au-delà des effets statiques, le calcul des effets des rafales de vent sur les constructions représente parfois un défi scientifique et technique. La Fondation Louis Vuitton récemment inaugurée près de Paris en est un parfait exemple. Les douze voiles de verre qui entourent le bâtiment imaginé par l'architecte Frank (...)
  • Soft Matter Days 2015
    From 2 July at 09:00 to 3 July 2015 at 17:50
    
  • Michael Le Bars (IRPHE, Marseille)
    Vendredi 26 juin 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Forme, durée de vie et instabilités d'un tourbillon dans un fluide stratifié tournant
    Les océans, les atmosphères planétaires, les disques d'accrétion, constituent autant de milieux naturels fluides stratifiés et tournants. Au sein de ces environnements complexes, des structures tourbillonnaires à grande échelle peuvent se développer, présentant une exceptionnelle longévité, comme par exemple La Grande (...)
  • Stéphane Roux (LMT, ENS Cachan)
    Vendredi 19 juin 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Faut-il 7 équations pour déterminer 7 inconnues ? ou 9 ? ou 5 ?
    L'imagerie et les mesures de champs offrent une considérable richesse d'information mais sont aussi affectées par un fort niveau de bruit. Cela pose donc le problème de la mesure de manière particulièrement aigüe. La redondance (« 9 équations pour 7 inconnues ») est utile mais nécessite de bien connaitre le bruit pour en (...)
  • Jonathan Rothstein (UMass Amherst)
    Vendredi 12 juin 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Viscoelastic Fluid Structure Interactions
    How Elastic Flow Instabilities can Induce Motion in Flexible Solid Structures When a flexible object such as an elastic sheet is placed in a flow of a Newtonian fluid, the shedding of separated vortices at high Reynolds number can drive the motion of the structure. This phenomenon is known as Vortex-Induced (...)
  • Bartosz Protas (McMaster University, Canada)
    Vendredi 5 juin 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Les tourbillons extrêmes et le problème des singularités en mécanique des fluides
    Dans cet exposé on va présenter quelques directions nouvelles de recherche et les résultats récents concernant l'étude du comportement extrême en hydrodynamique. Ces problèmes sont motivés par les estimations fondamentales de la croissance maximale de l'enstrophie dans les écoulements en 3D, qui sont intimement liées à la (...)
  • Pierre Coullet (Université de Nice Sophia Antipolis)
    Vendredi 29 mai 2015 de 11h00 à 12h00 - Bureau d'Etudes
    21 siècles de géométrie physique
    De la duplication du cube à la théorie universelle de la gravitation avec entre autres …Archimède, Apollonius, Alazen et Newton
  • Sylvain Courrech du Pont (MSC)
    Vendredi 22 mai 2015 de 11h00 à 12h00 - A1 (Urbain)
    Formes et dynamique des dunes
    La physique des dunes repose sur l'interaction entre le vent et une topographie érodable. Quand le vent souffle au-dessus d'une surface de sable, des dunes se forment dès lors que des grains sont transportés. Dans les déserts de sable, les vents soufflent généralement dans des directions et avec des forces différentes (...)
  • 20150424ad. David González-Rodríguez (LadHyX, Ecole Polytechnique)
    Vendredi 24 avril 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Biofluid Mechanics at the Subcellular Scale
    In this talk I will present two problems in cell mechanics where insight is gained through analogies with surface-tension-driven flow. First I will discuss how endothelial cells can oppose the opening of transcellular tunnels that are induced by certain bacterial infections. The experimentally observed dynamics (...)
  • 20150417ac. Kenny Breuer (Brown University)
    Vendredi 17 avril 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Aeromechanics of Bat Flight : From Live Animals to Robotic Models
    The elegance and maneuverability of bats during flight is unparalleled in both the natural and the man-made world, and they serve as a source of inspiration for scientists trying to understand the evolution of flight and for engineers designing highly agile flight vehicles. We have been exploring this rich (...)
  • 20150410ac. Jacques Treiner (UPMC et Sciences-Po, Paris)
    Vendredi 10 avril 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Changement climatique : pourquoi l'objectif des 2°C appartient, hélas, au passé
    Depuis la réunion internationale de Copenhague en décembre 2009 (COP15), un certain nombre de pays se sont engagés sur l'objectif de ne pas dépasser un réchauffement moyen de la surface de la Terre de 2°C. Cette valeur, choisie à la suite de négociations extrêmement difficiles entre 26 pays seulement (notamment sans l'UE) (...)
  • 20150403ab. Dmitry Kolomensky (McGill University)
    Vendredi 3 avril 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Numerical modelling of insect flight
    Numerical simulation can provide important insights to the mechanics of animal locomotion. In this talk, I will present a numerical method for modeling flapping flight of insects. It is based on a Fourier pseudo-spectral method for solving the Navier-Stokes equations. Time-varying solid boundaries are modeled (...)
  • 20150327ab. Ko Okumura (Ochanomizu University)
    Vendredi 27 mars 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Granular physics in two dimension : jamming, bubbling, clogging and meandering
    In this talk, we will discuss three small-scale granular experiments, all prepared in (quasi) two dimension : (1) drag friction in a granular medium [1], (2) granular statics and dynamics in a certain hopper [2], and (3) meandering air flow in a granular medium [3]. For the drag friction, we highlight the (...)
  • 20150320ab. Francisco Huera-Huarte (Universitat Rovira i Virgili)
    Vendredi 20 mars 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Drag based flapping propulsion with tip pitch control
    The swimming of fish is characterised by complex kinematics. These kinematics are governed not only by passive bony or cartilaginous structures, but also by active ones and tissue such as muscles. There has been a wide interest in the recent years regarding the understanding of the role of stiffness in flapping (...)
  • 20150313ab. Audrey Filella (IMFT, Toulouse)
    Vendredi 13 mars 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Mouvement et sillage de bulles confinées entre deux plaques, isolées ou en interaction
    Les écoulements à bulles sont présents dans un grand nombre d'applications qu'elles soient industrielles ou environnementales. La compréhension de la dispersion et de la taille des bulles est essentielle dans de nombreux procédés puisque les transferts de masse, chaleur et quantité de mouvement dépendent de la taille et (...)
  • 20150306ab. Luca Cipelletti (Laboratoire Charles Coulomb, Montpellier)
    Vendredi 6 mars 2015 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Jean-Baptiste Salmon (LoF, Bordeaux)
    Vendredi 13 février 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Séchage de gouttes de fluides complexes en géométrie confinée
    Je présenterais une méthode simple pour explorer le diagramme de phases d'un fluide complexe : l'observation du séchage d'une goutte confinée entre deux plaques de verre. Cette méthode permet d'identifier quantitativement plusieurs informations : diagramme des phases, activité de la solution, et coefficient de diffusion (...)
  • Jordi Ortin (Univerisitat de Barcelona)
    Vendredi 6 février 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Scale invariance, non-Gaussian fluctuations and intermittency in fluid imbibition
    I will review the work on viscous fluid invasion of a model open fracture carried out in Barcelona these last years, in the context of interfacial dynamics in disordered media. The model consists on a Hele-Shaw cell with carefully-controlled, randomly-distributed dichotomic variations of the gap thickness. (...)
  • Pas de séminaire PMMH. Journées de Physique Statistique
    Vendredi 30 janvier 2015 de 09h00 à 18h00 - Amphi Langevin, Bât N, 2e étage
    
  • Arnaud Antkowiak (Institut D'Alembert)
    Vendredi 23 janvier 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Enchevêtrement élastocapillaire dans les soies de capture d'araignée
    Les toiles et les soies d'araignées sont souvent exhibées comme des archétypes de structures légères, résistantes et constituées de polymères exceptionnels. Parmi les différentes soies produites par l'araignée, la plus remarquable est sans doute la soie de capture. La fonction première de cette soie est de permettre à (...)
  • Stéphane Régnier (ISIR, UPMC)
    Vendredi 16 janvier 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Microrobotique, microrobots : des systèmes interactifs pour les petites échelles
    Nous cherchons à développer des méthodes par lesquelles nous puissions interagir avec un monde intangible et invisible pour les humains, le micro-monde. L'un des défis des nanosciences est la manipulation et la caractérisation physique de micro-objets individuels dans leur environnement naturel. Ces objets peuvent être (...)
  • Emilie Dressaire (NYU School of Engineering)
    Vendredi 9 janvier 2015 de 11h00 à 12h00 - Bureau d'Etudes
    Tuning macroscopic flows using micro-structures
    In this talk, I will present experiments devoted to systems in which the presence of micrometer-scale structures has macroscopic, observable effects on the flow. We will first consider thin liquid films formed when jets impinge on solid surfaces such as hydraulic jumps and water bells. On a smooth surface, the (...)

• 2014

  • Pas de séminaire. Thèse de Jérémie Gachelin
    Vendredi 19 décembre 2014 de 10h00 à 12h00 - Amphi Langevin, Bât N, 2e étage
    
  • Harold Auradou (FAST, Orsay)
    Vendredi 12 décembre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Everything You Always Wanted to Know About the coupling between FLOW and BACTERIA But Were Afraid to Ask
    La nage des micro-organismes dans un fluide au repos a retenue beaucoup d'attention. Ici, nous considérerons les effets nouveaux comme la nage à contre courant ou la rhéotaxie qui apparaissent quand les bactéries sont placées dans un écoulement. Dans une premier temps, nous nous intéresserons au comportement des (...)
  • Leonardo Gordillo (MSC)
    Vendredi 5 décembre 2014 de 11h00 à 12h00 - Amphi Urbain (Esc. N, entresol)
    Waves generated with an underwater programmed displacement function
    In this talk, I will make a review of a set of laboratory experiments that we have carried out in the Laboratoire MSC at Université Paris Diderot. Our research is focused in the generation of surface waves in a fluid layer whose bottom undergoes an upward vertical motion. Experiments were run in two different (...)
  • Sara Jabbari-Farouji (Lab. Interdisciplinaire de physique)
    Vendredi 28 novembre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Plastic deformation mechanisms in amorphous and semicrystalline polymers
    Solid-like polymers are found in amorphous or semicrystalline state which consist of crystalline and amorphous regions. These polymeric materials have a diverse range of applications from packaging to more high-performance products such as bullet resistant vests and helmets. The wide-spread application of polymers (...)
  • Thierry Ondarçuhu (Groupe Nanosciences, CEMES, Toulouse)
    Vendredi 21 novembre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Etude du mouillage à l'échelle nanométrique par microscopie à force atomique.
    Même si le mouillage de surfaces a été largement étudié, de nombreuses questions restent ouvertes, notamment celles concernant la structure et la dynamique de la ligne de contact. Ainsi, la dissipation dans le coin de la goutte, au voisinage immédiat de la ligne de contact est mal connue, de même que l'ancrage sur les (...)
  • Martin Brinkmann (Max-Planck-Gesellschaft)
    Vendredi 14 novembre 2014 de 11h00 à 12h00 - Amphi Urbain (Esc. N, entresol)
    Depinning and arrest of liquid droplets on macroscopic and microscopic length scales
    In the first part of my talk I will discuss the classic depinning problem of a macroscopic drop on a plane surface driven by a volume force. To model the drop motion we assume homogeneous contact angle hysteresis and dissipation to occur only at the contact line. Considering the free interface of the liquid to be (...)
  • Laure Saint-Raymond (ENS)
    Vendredi 7 novembre 2014 de 11h00 à 12h00 - Bureau d'Etudes (Bât. L, 2ème étage)
    De la dynamique moléculaire à la théorie cinétique et l'hydrodynamique
    Un gaz peut être considéré soit comme un grand système de particules microscopiques en interaction, soit comme un milieu continu régi par des équations fluides. Une question naturelle est alors de comprendre si les deux types de modèles donnent des prédictions consistantes de la dynamique. Dans cet exposé, on se (...)
  • Soutenance de thèse de Mehdi Bouzid à 10h
    Vendredi 31 octobre 2014 de 10h00 à 12h00 - Amphithéâtre Holweck
    
  • Detlef Lohse (University of Twente)
    Vendredi 17 octobre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Surface nanobubbles : The big picture
    
  • Henrik Bruus (DTU, Denmark)
    Vendredi 3 octobre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Theoretical aspects of acoustofluidics : Streaming, radiation forces, and thermoviscous effects
    Inspired by the current increase in applications of acoustophoresis in biochip systems, my research group has conducted several theoretical and numerical studies of the basic physics of acoustofluidics including streaming, radiation forces, and thermoviscous effects. At the seminar an overview of our results will (...)
  • Journée Jean-Pierre Hulin, pas de séminaire PMMH
    Vendredi 26 septembre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Manoj Chaudhury (Lehigh University)
    Vendredi 19 septembre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Directed Motion of drops with Interfacial Contact
    We study the motion of small liquid drops on a surface when they are subjected to surface energy gradient, and or an external vibration (stochastic or structured). We study how the non-linear hysteresis rectify the imposed vibration. An interesting case is the random coalescence of condensed drops on a surface (...)
  • Ernesto Altshuler (University of Havana, Cuba)
    Vendredi 12 septembre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Extraterrestial sink dynamics in granular matter
    While the penetration of objects into granular media is well-studied, there is relatively little understanding of how objects settle in gravities, geff, different from that of Earth—a scenario potentially relevant to the geomorphology of planets and asteroids and also to their exploration using man-made devices. (...)
  • Pierre Recho (Institut Curie)
    Vendredi 5 septembre 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Contraction-driven cell motility
    We propose a mechanism for the initiation of cell motility that is based on myosin-induced contraction and does not require actin polymerization. The translocation of a cell is induced by symmetry breaking of the motor-driven flow, and the ensuing asymmetry gives rise to a steady motion of the center of mass of a (...)
  • Douglas J. Durian (University of Pennsylvania)
    Vendredi 11 juillet 2014 de 11h00 à 12h00 - Bureau d'Etudes
    The role of bubble shape in the coarsening of wet 2d foams
    We report on the statistics of bubble size, topology, and shape and on their role in the coarsening dynamics for foams consisting of bubbles compressed between two parallel plates. The design of the sample cell permits control of the liquid content, through a constant pressure condition set by the height of the (...)
  • Eric Furst (University of Delaware)
    Vendredi 4 juillet 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Directing colloidal self-assembly with toggled fields
    Suspensions of polarizable colloids are expected to form crystalline equilibrium phases when exposed to a steady, uniform field. However, when colloids become localized this field-induced phase transition arrests and the suspension persists indefinitely as a kinetically trapped, percolated structure. The (...)
  • James Hanna (Virginia Polytechnic Institute and State University)
    Vendredi 27 juin 2014 de 11h00 à 12h00 - A4 (Langevin)
    Metrically constrained dynamics : lariats, chain siphons, and whirling skirts
    The dynamics of classical, inextensible strings and sheets are in some sense intermediate between those of point particles and rigid bodies. I will discuss simple models of these highly flexible bodies, focusing on the inertial dynamics of curves and surfaces with metric constraints. Symmetries of these (...)
  • Michael L. Falk (Johns Hopkins University)
    Vendredi 20 juin 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Relating Continuum, Mesoscale and Atomistic Models of Amorphous Plastic Response
    In this informal seminar I plan to discuss the issues at stake in understanding how amorphous materials respond to stress. I will briefly introduce the ways that atomistic simulation techniques like molecular dynamics and athermal quasistatic shear are used to investigate disordered materials. I will also review (...)
  • Julien Chopin (Universidade Federal do Rio de Janeiro)
    Vendredi 13 juin 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Morphological instabilities of a stretched twisted ribbon
    Finding strategies toward developing functional shapes at smaller and smaller scales has been a focus of intense research in elastic materials. Our investigations show that a wide variety of shapes and instabilities can be obtained by simply varying the applied twist and tension [1]. Due to its geometry which is (...)
  • Arshad Kudrolli (Clark U.) : Active Granular Matter
    Vendredi 6 juin 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Active Granular Matter
    We discuss experiments designed with granular matter to develop the physics of self-propelled particle systems which move and interact via simple physical rules. The shape and mass distribution of a particle can be exploited to fabricate elements which perform random motions or directed random walks on a vibrated (...)
  • Franck Ruffier (Institut des Sciences du Mouvement, Marseille)
    Vendredi 23 mai 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Des Abeilles aux robots et vice-versa
    Les insectes ailés ont résolu des problèmes ardus tels que la stabilisation du vol, l'évitement d'obstacles en 3D, la poursuite de cibles, l'odométrie, l'atterrissage sans piste aménagée et l'atterrissage sur des cibles en mouvements, problèmes sur lesquels bute encore la robotique autonome contemporaine. Certains (...)
  • Benoît Pier (LMFA, École Centrale de Lyon)
    Vendredi 16 mai 2014 de 11h00 à 12h00 - A4 (Langevin)
    Instabilités convectives et absolues dans l'écoulement de Taylor—Couette—Poiseuille
    Colin Leclercq, Benoît Pier, Julian Scott L'écoulement de Taylor—Couette, entre deux cylindres concentriques en rotation différentielle, est l'archétype de l'instabilité centrifuge et certainement l'une des configurations les plus étudiées en instabilités hydrodynamiques. L'effet soit d'un débit axial soit de (...)
  • Gareth McKinley (MIT) : Exploiting & Optimizing Viscoelastic Effects in Microfluidic Flows
    Vendredi 25 avril 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Exploiting and Optimizing Viscoelastic Effects in Microfluidic Flows
    I will describe two different scenarios in which viscoelastic effects become extremely important in microfluidic devices and can be exploited to optimize the operation of a proposed microfluidic device. In the first example we consider optimizing the shape of a microfluidic extensional rheometer designed to (...)
  • Jean-François Joanny (ESPCI ParisTech) : Cortical actin layers & cytokinesis dynamics
    Vendredi 18 avril 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Cortical actin layers and cytokinesis dynamics
    In this talk, we discuss first the properties of the actin cortical layer in contact with the plasma membrane of a cell using the hydrodynamic theory of active gels : within this framework, the cortical layer can be viewed as an active prewetting layer. We also discuss the dynamical properties of the layer and the (...)
  • Frédéric Chevy (Laboratoire Kastler Brossel, ENS) : Ondes & tourbillons dans les fluides & les superfluides
    Vendredi 11 avril 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Ondes et tourbillons dans les fluides et les superfluides
    Ondes et tourbillons sont des sources de dissipations universelles en mécanique des fluides. Dans cet exposé je dresserai un parallèle entre les mécanismes de dissipation dans les fluides classiques et les superfluides d'atomes ultra-froids, en soulignant comment les concepts hérités de l'hydrodynamique classique (...)
  • Howard Stone (Princeton U.) : Elementary channel flows with surprising responses : (i) Biofilms & flow and (ii) Trapping of bubbles in stagnation point flows
    Vendredi 4 avril 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Elementary channel flows with surprising responses : (i) Biofilms and flow and (ii) Trapping of bubbles in stagnation point flows
    In this talk I describe two distinct problems that we have studied where seemingly modest variations in an elementary channel flow produce new effects. First, we investigate some influences of flow on biofilms. In particular, we identify the formation of biofilm streamers, which are filaments of biofilm extended (...)
  • Alberto Aliseda (University of Washington)
    Vendredi 28 mars 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Experimental study of turbulent multiphase flows : inertial particles, collisions and bubble dynamics
    Turbulent multiphase flows encompass some of the biggest open questions in modern fluid mechanics. The dynamics of solid particles, liquid droplets and gas bubbles represent significant gaps in our fundamental understanding, while at the same time, being of great relevance in many industrial and environmental (...)
  • Yves Pomeau (LPS, ENS)
    Vendredi 21 mars 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Dans le déroulement infini de sa lame...
    Ce titre, emprunté à Baudelaire (« L'homme et la mer » dont le premier vers est : Homme libre , toujours tu chériras la mer) voudrait rappeler que le spectacle de la mer et des vagues a toujours intéressé les artistes, poètes (depuis Homère), peintres (Hokusai, Courbet) et aussi un peu les scientifiques. Le premier de ceux (...)
  • Anthony Herrel (Muséum national d'Histoire naturelle)
    Vendredi 14 mars 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Biomechanics and evolution in snakes
    Morphological convergence as a consequence of extreme functional demands : examples from the feeding system of natricine snakes Despite repeated acquisitions of aquatic or semi-aquatic lifestyles revolving around piscivory, snakes have not evolved suction feeding. Instead, snakes use frontally or laterally (...)
  • Richard-Emmanuel Eastes (ESPCI ParisTech et ENS)
    Vendredi 7 mars 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Comprendre les sciences...
    Si je suis le déroulé d'une démonstration abstraite, du théorème initial aux conclusions, ai-je compris le phénomène qu'elles illustrent ? A l'inverse, peut-on comprendre les phénomènes de la nature et de l'univers sans connaissance scientifique ? Au-delà de l'approche qualitative des phénomènes, peut-on parler d'approche (...)
  • Pas de séminaire PMMH
    Vendredi 28 février 2014 de 11h00 à 12h00 - A4 (Langevin)
    Pas de séminaire PMMH
    
  • Jacopo Seiwert (IPR, Rennes)
    Vendredi 21 février 2014 de 11h00 à 12h00 - A4 (Langevin)
    Generation and deformation of soap films
    Liquid foams are widely used in industry for their high effective viscosity, whose local origin is still unclear. We present new theoretical and experimental results on the physics of soap films, in configurations mimicking the elementary deformation occurring during foam shearing. Theoretically, we study the (...)
  • Jeff Porter (Universidad Politécnica de Madrid)
    Vendredi 14 février 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Vibrated fluids : Faraday waves, cross-waves, and vibroequilibria
    The behavior of vibrated fluids and, in particular, surface or interfacial instabilities, has been the subject of continued experimental and theoretical attention since Faraday's seminal experiments in 1831. Both orientation and frequency are critical in determining the response of the fluid to excitation. Low (...)
  • Lev Truskinovsky (LMS, Ecole Polytechnique)
    Vendredi 7 février 2014 de 11h00 à 12h00 - Amphi Langevin (Bât N, 2ème étage)
    Contraction driven cell crawling
    The two main active processes allowing cells to crawl are myosin contraction and actin polymerization. We first show that these two mechanisms are complimentary allowing cells to handle such fundamentally different tasks as pushing and pulling. Then we focus on contraction dominated crawling involved, for (...)
  • Journées de Physique Statistique 2014
    Du 30 janvier à 09h00 au 31 janvier 2014 à 18h30 - Amphithéâtre Paul-Langevin
    Journées de Physique Statistique 2014
    http://comphys.ethz.ch:8080/jstat/
  • Yohann Duguet (LIMSI-CNRS, Orsay)
    Vendredi 24 janvier 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Transition à la turbulence dans l'écoulement de Couette plan
    L'écoulement de Couette plan correspond à l'écoulement de fluide incompressible entre deux plaques parallèles qui cisaillent le fluide de façon homogène. Cet écoulement est, avec la transition dans les écoulements de type Poiseuille plan ou cylindrique, un prototype de la transition à la turbulence dite "sous-critique", (...)
  • Julien Scheibert (Ecole Centrale de Lyon)
    Vendredi 17 janvier 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Transition from static to kinetic friction : insights from numerical experiments
    The contact between macroscopic rough solids is made of many micrometric asperities in contact. Under increasing shear force, each microcontact deforms, reaches its breaking threshold, and triggers a local micro-slip event. In some conditions, such an event can destabilize neighbouring microcontacts and a (...)
  • Fernando Peruani (Université de Nice)
    Vendredi 10 janvier 2014 de 11h00 à 12h00 - Bureau d'Etudes
    Quasi-long range order and sub-diffusion in systems of active particles in heterogeneous media
    The rapidly expanding study of active particles has focused so far almost exclusively, theoretically as well as experimentally, on the statistical description of particle motion in idealized, homogeneous spaces. However, the great majority of natural active particle systems takes place, in the wild, in (...)

• 2013

  • Edgar E González (Faculty of Engineering, Pontificia Universidad Javeriana, Bogotá, Colombia)
    Vendredi 13 décembre 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Complex hollow nanoparticles and their applications
    Complex hollow nanostructures using simultaneous or sequential action of Kirkendall effect and galvanic exchange at room temperature can be obtained [1]. By this method it becomes possible to control the morphology and composition of the nanostructures to enhance their optical, thermal and catalytic properties (...)
  • Journée LJP/PMMH
    Vendredi 6 décembre 2013 de 11h00 à 12h00 - Bureau d'Etudes
    
  • Valerie Vidal (ENS de Lyon)
    Vendredi 29 novembre 2013 de 11h00 à 12h00 - Amphi Joliot
    Injection d'air dans un milieu granulaire immerge : une (brève) revue phénoménologique
    L'injection de gaz dans un milieu granulaire immergé dans un fluide donne naissance à des motifs d'invasion et des dynamiques complexes. Je présenterai une revue des phénomènes observés en laboratoire lorsqu'on injecte de l'air à la base d'un lit granulaire immergé dans l'eau, confiné dans une cellule de Hele-Shaw (...)
  • Elise Lorenceau (Laboratoire Navier, Ecole des Ponts)
    Vendredi 22 novembre 2013 de 11h00 à 12h00 - A4 (Langevin)
    Transport de liquides variés au sein d'une mousse aqueuse
    Nous présentons différentes configurations de transport de liquides via la phase continue d'une mousse aqueuse. Dans un premier temps, nous évaluons la capacité d'une mousse aqueuse à transporter une phase organique immiscible, telle qu'une huile silicone. Lorsque la mousse est stabilisée par des agents de surface à (...)
  • Véronique Lazarus (Laboratoire FAST)
    Vendredi 15 novembre 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Comment prédire la forme des fissures ?
    Un bateau qui se casse, une vitre qui éclate, du bois qui se fendille, une roche qui se rompt, une peinture qui craquelle, un os qui se fracture...les fissures nous entourent et leur aspect nous intrigue parfois. La mécanique linéaire élastique de la rupture permet en principe de prédire leur forme. Mais en pratique, (...)
  • Séminaire PMMH : Christophe Gissinger (LPS, ENS)
    Vendredi 8 novembre 2013 de 11h00 à 12h00 - Bureau d'Etudes

    "L'effet dynamo en laboratoire"

    
    L'effet dynamo en laboratoire
    Le magnétisme de la plupart des étoiles et planètes, y compris la Terre, est engendré par 'effet dynamo', c'est-à-dire la régénération auto-entretenue d'un champ magnétique grâce aux mouvements turbulents d'un fluide conducteur de l'électricité, par exemple le fer liquide dans le noyau terrestre. Au cours des dernières (...)
  • Test SP1
    Vendredi 1er novembre 2013 de 09h00 à 10h00 - A4 (Langevin)
    
  • Ignacio Pagonabarraga (Universitat de Barcelona)
    Vendredi 25 octobre 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Emergent dynamic regimes in active suspensions : spontaneous and forced structures
    Active systems generate motion due to energy consumption, usually associated to their internal metabolism or to appropriate, localized, interfacial chemical reactivity. As a result, these systems are intrinsically out of equilibrium and their collective properties result from a balance between their direct (...)
  • Thomas Duriez (Institut Pprime, Poitiers)
    Vendredi 18 octobre 2013 de 11h00 à 12h00 - Amphi Langevin
    Close loop control of complex systems : low order linear model approach and nonlinear model free approach
    Active turbulence control is a rapidly evolving, interdisciplinary field of research. In particular, closed- loop control with sensor information can offer distinct benefits over blind open-loop forcing. The range of current and future engineering applications of closed-loop turbulence control has truly epic (...)
  • Corentin Coulais (Leiden University)
    Vendredi 4 octobre 2013 de 11h00 à 12h00 - Bureau d'Etudes
    ''Can you shape the feel of a thing ?'' : Tunable mechanical meta-materials
    We probe the mechanical response of 2d elastic media, structured by a crystalline pattern of holes of two different sizes. While compressed under uniaxial loading, the holes pattern transforms, the overall material undergoes an auxetic mechanical response. Hole size and aspect ratio play a crucial role on this (...)
  • Florence Haudin (NonLinear Physical Chemistry Unit, Université Libre de Bruxelles)
    Vendredi 27 septembre 2013 de 11h00 à 12h00 - Amphi Urbain
    Buoyancy- and chemically-driven pattern formation in the contact zone between two fluids
    To characterize phenomena occuring in the contact zone between two fluids, it is possible to place them between two plates separated by a small gap, thus confining the flows in a quasi 2D geometry. We will here present two studies performed in this type of set up, called Hele-Shaw cell. In a first part, we will (...)
  • Igor Aronson (Argonne National Laboratory, USA)
    Vendredi 20 septembre 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Cell Movement on Soft Engineered Substrates
    Self-propelled motion, emerging spontaneously or in response to external cues, is a hallmark of living organisms. Systems of self-propelled synthetic particles are also relevant for multiple applications, from targeted drug delivery to the design of self-healing materials. Self-propulsion relies on the force (...)
  • Roberto Toro (Institut Pasteur)
    Vendredi 13 septembre 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Development and evolution of brain folding and brain organisation
    The mammalian brain is astonishingly diverse. Not only its size varies several orders of magnitude – from the 3 grams of the mouse brain to the 6 kg of the blue whale brain – but also its geometry and function. There is indeed a striking, largely unexplained, relationship between the folding of the mammalian brain (...)
  • Jean-Marc Chomaz (LadHyX, Ecole Polytechnique)
    Vendredi 6 septembre 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Science and art of sculpturing fluids
    The role of aesthetics is analysed through particular examples of my realisations both in sciences and in the art & science. Sur l'image : Installation Fluxus devant la bourse du commerce à Paris pour la foire d'art contemporain CUTLOG en octobre 2012, schéma de fonctionnement et mise au point au laboratoire avec (...)
  • Netta Cohen (University of Leeds, UK)
    Vendredi 19 juillet 2013 de 11h00 à 12h00 - Amphi Langevin
    Animal microswimmers : closing the neuro-environment loop
    Planar undulations are a common mechanism for biological locomotion across many scales and phyla. Here I review recent progress in understanding the locomotion control of a microscopic nematode worm, C. elegans, and the interplay between neural control, passive and active body forces and the interaction with (...)
  • Roberto Zenit (UNAM, México)
    Vendredi 12 juillet 2013 de 11h00 à 12h00 - Amphi Langevin
    Locomotion of microorganisms in complex fluids
    The fundamental mechanisms of microorganism motility have been extensively studied in the past. Most previous work focused on cell locomotion in simple (Newtonian) fluids. However, in many cases of biological importance (including mammalian reproduction and bacterial infections), the fluids that surround the (...)
  • Stephan Herminghaus (Max Planck Gesellschaft)
    Vendredi 5 juillet 2013 de 11h00 à 12h00 - Amphi Holweck
    Active emulsions : soft matter far from thermal equilibrium
    A number of experiments are presented dealing with 'active' emulsions, i.e., collections of droplets the ingredients of which are not in thermal equilibrium. As a consequence, they exhibit unusual collective behaviour, which may resemble dynamic patterns they are sometimes observed in cell cultures, or swarming as (...)
  • Marc-Etienne Brachet (LPS, ENS)
    Vendredi 28 juin 2013 de 11h00 à 12h00 - Bureau d'Etudes
    The incompressible Euler singularity problem
    A central open question in classical fluid dynamics is whether the incompressible three-dimensional Euler equations with smooth initial conditions develop a singularity after a finite time. Recent results on this problem reported in [1] will be presented in the seminar. [1] Miguel D. Bustamante and Marc Brachet, (...)
  • Lucas Goehring (Max Planck Institute Goettingen)
    Vendredi 21 juin 2013 de 11h30 à 12h30 - Bureau d'Etudes
    Evolving crack patterns : mud cracks, columnar joints, and polygonal terrain
    Contraction cracks can form captivating patterns, such as the artistic craquelure sometimes found in pottery glazes, to the cracks in dried mud, or the polygonal networks covering the polar regions of Earth and Mars. Two types are frequently encountered : those with irregular rectilinear patterns, such as that (...)
  • Hans Herrmann (ETH Zürich)
    Vendredi 14 juin 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Packing of wires in cavities and growing surfaces
    We investigate the morphologies and maximum packing density of thin wires packed into spherical cavities. Using simulations and experiments with nylon lines, we find that ordered as well as disordered structures emerge, depending on the amount of internal torsion. We find that the highest packing densities are (...)
  • Marc Rabaud (Laboratoire FAST)
    Vendredi 7 juin 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Sillages de vague des bateaux à la surface de l'eau
    Depuis le travail de Lord Kelvin on sait que le sillage d'un objet se déplaçant à la surface de l'eau forme un "V" caractéristique dont l'angle ne dépend ni de la forme de l'objet ni de la vitesse. Et pourtant ... nous venons de montrer que ce résultat communément admis n'est pas toujours observé [1]. Des mesures (...)
  • Geoff Spedding (University of Southern California)
    Vendredi 31 mai 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Aerodynamic Efficiency in Small and Large Aircraft
    The aerodynamic efficiency of an aircraft is conventionally measured by the dimensionless lift to drag ratio, L/D, and higher values are almost always better. The design or evolution of flying devices involves a lot more than this single measure, but it is still interesting to enquire how close any given device (...)
  • Zhigang Suo (Harvard University)
    Vendredi 24 mai 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Soft active materials and soft machines
    Machines in engineering use mostly hard materials, while machines in nature are often soft. This difference has been an inspiration for the nascent field of soft machines. What does softness impart to the life of animals and plants ? Softness enables large deformation, which in turn provides vital functions. (...)
  • Frédéric Léchenault (LPS, ENS)
    Vendredi 26 avril 2013 de 11h00 à 12h00 - Amphi Langevin
    Folds and loops
    In this seminar, I will present two experimental situations involving the confinement of elastic objects. First I will focus on the mechanical response of a folded thin sheet. I will show that crease opening and face bending give two competing contributions to the elastic energy, which gives rise to a (...)
  • Abdul Barakat (LadHyX, Ecole Polytechnique)
    Vendredi 19 avril 2013 de 11h00 à 12h00 - Amphi Urbain
    Mechanotransduction in Vascular Endothelial Cells : Mechanisms and Implications
    The ability of arterial endothelial cells, the cells lining the inner surfaces of blood vessels, to respond to mechanical forces associated with blood flow is essential for normal vascular function. Abnormalities in endothelial cell mechanotransduction play a critical role in the development and progression of (...)
  • Jérôme Hoepffner (Institut D'Alembert)
    Vendredi 12 avril 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Recoil of a liquid filament : escape of the pinching through vortex ring inception
    Un corps liquide tend à se rassembler sous la forme d'une sphère sous l'effet de sa tension de surface. Les processus dynamiques rapides limités par l'inertie peuvent faire que ce corps liquide se fragmentera en fait plutôt en plusieurs sphères. Nous mettons en évidence un nouveau mécanisme où la création d'un anneau (...)
  • Tristan Baumberger (UPMC)
    Vendredi 5 avril 2013 de 11h00 à 12h00 - Amphi Langevin
    Hydrogels : « physiques » et/ou « chimiques » ? – Relaxations, vieillissement, rupture -
    Les hydrogels de polymères sont appelés à jouer un rôle essentiel dans les applications biomédicales. En témoigne le nombre sans cesse croissant d'articles proposant des structures de réseaux biocompatibles de plus en plus élaborées. Paradoxalement, l'étude des mécanismes physiques fondamentaux en jeu dans les propriétés (...)
  • Scott Waitukaitis (University of Chicago)
    Vendredi 29 mars 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Impact-Activated Solidification of Dense Suspensions
    Shear-thickening, non-Newtonian fluids have typically been investigated under steady-state conditions. This approach has produced two pictures for suspension response to imposed forcing. In the weak shear-thickening picture, the response is typically attributed to the hydrodynamic interactions giving rise to (...)
  • Anne Davaille (Laboratoire FAST)
    Vendredi 22 mars 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Convection dans les fluides complexes : du laboratoire aux planètes
    L'évolution de la Terre et de son refroidissement depuis son accrétion jusqu'à nos jours reste une des questions fondamentales des Sciences de l'univers. Comprendre l'histoire de notre planète, et ses différences par rapport aux autres planètes, est une étape-clef pour comprendre l'origine et la préservation de la vie. (...)
  • Camille Duprat (PMMH)
    Vendredi 15 mars 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Écoulements élastocapillaires
    La déformation d'objets flexibles sous l'effet des forces capillaires (élastocapillarité) et leur interaction avec un écoulement (elastohydrodynamique) interviennent dans de nombreux processus biologiques, géophysiques et industriels. Afin de mieux comprendre certains de ces phénomènes, je présenterai plusieurs systèmes (...)
  • Romain Monchaux (ENSTA ParisTech)
    Vendredi 8 mars 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Inertial particles in turbulence : preferential concentration and settling velocity
    Turbulent flows laden with inertial particles occur in many industrial and environmental situations (pollutant dispersion, plankton, engine optimization…) During the last forty years, many properties of these flows have been evidenced, nevertheless, a model equation describing them is still out of reach, (...)
  • Thomas Salez (ENS/ESPCI)
    Vendredi 1er mars 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Polymers in Flatland : Self-Similarity and Nanorheology
    The study of ultra-thin polymer nanofilms is a rich and productive field for applied mathematics, fundamental physics, physiology and engineering. It has been enlightened by the recent results on dewetting, nanoindentation, electrostatic instabilities and micro- bubbles. We report here on a novel and simple (...)
  • Thierry Savin (ETH Zürich)
    Vendredi 22 février 2013 de 11h00 à 12h00 - A4 (Langevin)
    Occlusive flow of red blood cells
    When red blood cells (RBCs) move through narrow capillaries in the microcirculation, they deform as they flow. In pathophysiological processes such as sickle cell disease and malaria, RBCs' deformability is altered and their motion is severely restricted. This can lead to vaso-occlusive crises with dramatic (...)
  • Michaël De Volder (KU Leuven)
    Vendredi 8 février 2013 de 11h00 à 12h00 - Amphi Schützenberger
    Elasto-capillary fabrication of 3D CNTs microstructures
    Carbon nanotubes (CNTs), as well as graphene, have been pivotal in captivating the interest of scientists, the general public, and industry in nanotechnology. The latter can best be quantified by the production capacity of CNTs which is growing exponentially, and is currently estimated at 5000 ton/yr. However, few (...)
  • Valentin Leroy (MSC, Université Paris Diderot)
    Vendredi 1er février 2013 de 11h00 à 12h00 - A4 (Langevin)
    Acoustique des bulles : du liquide bulleux à la mousse
    La présence d'inclusions gazeuses dans un matériau change drastiquement ses propriétés acoustiques. Le séminaire en montrera quelques exemples, en décrivant notamment les cristaux phononiques de bulles que nous avons obtenus. Depuis peu, nous nous intéressons au cas où la concentration en gaz devient très importante : les (...)
  • Pas de séminaire PMMH (Journées de Physique Statistique)
    Vendredi 25 janvier 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Journées de Physique Statistique 24-25 janvier 2013
    Site web
  • John W. M. Bush (MIT)
    Vendredi 18 janvier 2013 de 11h00 à 12h00 - Amphi Langevin
    Pilot-wave hydrodynamics
    Yves Couder, Emmanuel Fort and coworkers have recently discovered that droplets walking on a vibrating fluid bath exhibit several features previously thought to be peculiar to the microscopic, quantum realm. Theoretical developments provide rationale for the complex behavior of the bouncing droplets, and yield a (...)
  • Lara Vozella (Università degli Studi di Torino)
    Vendredi 11 janvier 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Transport and mixing in Rayleigh-Taylor turbulence
    The Rayleigh-Taylor (RT) instability is a fluid-mixing mechanism arising at the interface between two fluids of different density when the heavy, denser, fluid is accelerated into the lighter one. The reduction of fluid potential energy drives the growth of a perturbation along the interface to form a mixing (...)
  • Arnaud Lazarus (MIT)
    Vendredi 4 janvier 2013 de 11h00 à 12h00 - Bureau d'Etudes
    Equilibrium and stability analysis of slender elastic rods
    New interesting challenges arise in the mechanics of slender elastic rods with the burgeoning of new scientific fields such as soft materials, nanotechnologies, stretchable electronics or even physical computer animation. One of the common emerging concerns is the efficient modeling of the very large deformations (...)

• 2012

  • Séminaire : Pierre-Thomas Brun (EPFL)
    Vendredi 14 décembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    From the Viscous Sewing Machine to the Cowboy's Lasso
    Part I : The fluid mechanical sewing machine A thin thread of viscous fluid falls onto a moving conveyer belt and lays down in a plethora of complex "stitch" patterns depending on the belt speed and the height of fall. This experiment is well documented in the literature and we used direct numerical simulations to (...)
  • Séminaire : Pierre-Thomas Brun (EPFL)
    Vendredi 14 décembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    From the Viscous Sewing Machine to the Cowboy's Lasso
    Part I : The fluid mechanical sewing machine A thin thread of viscous fluid falls onto a moving conveyer belt and lays down in a plethora of complex "stitch" patterns depending on the belt speed and the height of fall. This experiment is well documented in the literature and we used direct numerical simulations to (...)
  • John Hinch (University of Cambridge)
    Vendredi 7 décembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Explaining the flow of elastic liquids
    The behaviour of elastic liquids does not follow simply from our understanding of both elastic solids and viscous liquids. Four anomalous behaviours will be discussed :— (i) long wakes at low Reynolds numbers, (ii) large vortices upstream of a constriction, (iii) long times for capillary forces to squeeze a (...)
  • John Hinch (University of Cambridge)
    Vendredi 7 décembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Explaining the flow of elastic liquids
    The behaviour of elastic liquids does not follow simply from our understanding of both elastic solids and viscous liquids. Four anomalous behaviours will be discussed :— (i) long wakes at low Reynolds numbers, (ii) large vortices upstream of a constriction, (iii) long times for capillary forces to squeeze a (...)
  • Andrea Scagliarini (Technische Universiteit van Eindhoven)
    Vendredi 30 novembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Emergent structures and dynamics in suspensions of active colloids
    Active fluids, such as suspensions of self-propelled particles or of cytoskeletal filaments and molecular motors, are a fascinating example of soft matter displaying non-trivial collective behaviours which represent issues in non-equilibrium statistical physics. Moreover, the recent development of techniques to (...)
  • Andrea Scagliarini (Technische Universiteit van Eindhoven)
    Vendredi 30 novembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Emergent structures and dynamics in suspensions of active colloids
    Active fluids, such as suspensions of self-propelled particles or of cytoskeletal filaments and molecular motors, are a fascinating example of soft matter displaying non-trivial collective behaviours which represent issues in non-equilibrium statistical physics. Moreover, the recent development of techniques to (...)
  • Hartmut Löwen (Universität Düsseldorf)
    Vendredi 23 novembre 2012 de 11h00 à 12h30 - A4 (Langevin)
    Collective dynamics of self-propelled particles : from crystallization to turbulence
    We explore active rod-like colloidal particles by computer simulation and theory. First of all, the Brownian motion of self-propelled particles is described. Then Brownian dynamics simulations are used to explore the non-equilibrium dynamics of concentrated self-propelled rods which are interacting via a Yukawa (...)
  • Hartmut Löwen (Universität Düsseldorf)
    Vendredi 23 novembre 2012 de 11h00 à 12h30 - A4 (Langevin)
    Collective dynamics of self-propelled particles : from crystallization to turbulence
    We explore active rod-like colloidal particles by computer simulation and theory. First of all, the Brownian motion of self-propelled particles is described. Then Brownian dynamics simulations are used to explore the non-equilibrium dynamics of concentrated self-propelled rods which are interacting via a Yukawa (...)
  • Antonin Eddi (University of Twente)
    Vendredi 16 novembre 2012 de 11h00 à 12h30 - Amphithéâtre Frédéric Joliot (A3)
    Coalescence de gouttes posées sur un substrat
    Nous étudions expérimentalement et théoriquement la coalescence de 2 gouttes visqueuses déposées sur un substrat. Nous considérons le cas où les deux gouttes peuvent avoir des angles de contact différents, ce qui rend la coalescence asymétrique. Des expériences avec une vue de côté révèlent que le pont capillaire qui relie (...)
  • Antonin Eddi (University of Twente)
    Vendredi 16 novembre 2012 de 11h00 à 12h30 - Amphithéâtre Frédéric Joliot (A3)
    Coalescence de gouttes posées sur un substrat
    Nous étudions expérimentalement et théoriquement la coalescence de 2 gouttes visqueuses déposées sur un substrat. Nous considérons le cas où les deux gouttes peuvent avoir des angles de contact différents, ce qui rend la coalescence asymétrique. Des expériences avec une vue de côté révèlent que le pont capillaire qui relie (...)
  • Lev Truskinovsky (LMS, Ecole Polytechnique)
    Vendredi 9 novembre 2012 de 11h00 à 12h00 - Amphi Joliot
    Criticality in plasticity and martensitic phase transitions
    
  • Lev Truskinovsky (LMS, Ecole Polytechnique)
    Vendredi 9 novembre 2012 de 11h00 à 12h00 - Amphi Joliot
    Criticality in plasticity and martensitic phase transitions
    
  • Sara Jabbari (LPTMS, Université de Paris-Sud 11)
    Vendredi 26 octobre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Interplay of anisotropy and interactions in charged colloidal disks
    Charged plate-like colloidal suspensions such as gibbsite and some clays exhibit interesting and rich phase behavior including liquid-crystalline and arrested gel-like states. The anisotropic shape of such particles suggests that these materials could form liquid crystalline phases due to the competition between (...)
  • Sara Jabbari (LPTMS, Université de Paris-Sud 11)
    Vendredi 26 octobre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Interplay of anisotropy and interactions in charged colloidal disks
    Charged plate-like colloidal suspensions such as gibbsite and some clays exhibit interesting and rich phase behavior including liquid-crystalline and arrested gel-like states. The anisotropic shape of such particles suggests that these materials could form liquid crystalline phases due to the competition between (...)
  • Lucilla de Arcangelis (Seconda Università degli Studi di Napoli)
    Vendredi 19 octobre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Balance between excitation and inhibition controls the temporal organization of neuronal avalanches
    Neuronal avalanches are a novel mode of activity in neuronal networks, experimentally found in vitro and in vivo, and exhibit a robust critical behaviour. Avalanche activity can be modelled within the self-organized criticality framework, including threshold firing, refractory period and activity-dependent (...)
  • Lucilla de Arcangelis (Seconda Università degli Studi di Napoli)
    Vendredi 19 octobre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Balance between excitation and inhibition controls the temporal organization of neuronal avalanches
    Neuronal avalanches are a novel mode of activity in neuronal networks, experimentally found in vitro and in vivo, and exhibit a robust critical behaviour. Avalanche activity can be modelled within the self-organized criticality framework, including threshold firing, refractory period and activity-dependent (...)
  • Kripa Varanasi (MIT)
    Vendredi 5 octobre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Nanoengineered Surfaces for Enhanced Thermal-Fluid Transport Properties : Studies on Dynamic Wetting and Phase Change Phenomena
    Thermal-fluid-surface interactions are ubiquitous in multiple industries including Energy, Water, Agriculture, Transportation, Electronics Cooling, Buildings, etc. Over the years, these systems have been designed for increasingly higher efficiency using incremental engineering approaches that utilize system-level (...)
  • Kripa Varanasi (MIT)
    Vendredi 5 octobre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Nanoengineered Surfaces for Enhanced Thermal-Fluid Transport Properties : Studies on Dynamic Wetting and Phase Change Phenomena
    Thermal-fluid-surface interactions are ubiquitous in multiple industries including Energy, Water, Agriculture, Transportation, Electronics Cooling, Buildings, etc. Over the years, these systems have been designed for increasingly higher efficiency using incremental engineering approaches that utilize system-level (...)
  • Marc-Antoine Fardin (ENS Lyon)
    Vendredi 28 septembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Des Bandes de cisaillement à la turbulence viscoélastique : une étude en rhéologie
    En rhéologie, les solutions de micelles géantes sont utilisées comme systèmes modèles depuis près de trente ans. Elles furent d'abord étudiées aux faibles déformations, pour lesquelles elles se comportent comme des fluides de Maxwell, l'exemple le plus simple de viscoélasticité. Par la suite, il fut découvert qu'aux plus (...)
  • Marc-Antoine Fardin (ENS Lyon)
    Vendredi 28 septembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Des Bandes de cisaillement à la turbulence viscoélastique : une étude en rhéologie
    En rhéologie, les solutions de micelles géantes sont utilisées comme systèmes modèles depuis près de trente ans. Elles furent d'abord étudiées aux faibles déformations, pour lesquelles elles se comportent comme des fluides de Maxwell, l'exemple le plus simple de viscoélasticité. Par la suite, il fut découvert qu'aux plus (...)
  • Jacques Treiner (UPMC et Sciences-Po Paris)
    Vendredi 21 septembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Les Marchands de Doute
    Depuis les années 1960, des industriels et certains scientifiques américains se sont organisés pour introduire un doute systématique à propos de résultats scientifiques pourtant bien établis, dès lors que les conclusions pouvaient déboucher sur une régulation étatique : le tabac et le cancer du poumon, la « Guerre des (...)
  • Jacques Treiner (UPMC et Sciences-Po Paris)
    Vendredi 21 septembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Les Marchands de Doute
    Depuis les années 1960, des industriels et certains scientifiques américains se sont organisés pour introduire un doute systématique à propos de résultats scientifiques pourtant bien établis, dès lors que les conclusions pouvaient déboucher sur une régulation étatique : le tabac et le cancer du poumon, la « Guerre des (...)
  • Keith A. Seffen (University of Cambridge)
    Vendredi 14 septembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Shape Changing Shell Structures
    In this presentation, I will describe some of the thin-walled "shell" structures developed by our research group, which display unusual shape-changing capabilities ; in particular, I will discuss how we have been inspired by similar behaviour in Nature, as well as introducing potential applications, and I will (...)
  • Keith A. Seffen (University of Cambridge)
    Vendredi 14 septembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Shape Changing Shell Structures
    In this presentation, I will describe some of the thin-walled "shell" structures developed by our research group, which display unusual shape-changing capabilities ; in particular, I will discuss how we have been inspired by similar behaviour in Nature, as well as introducing potential applications, and I will (...)
  • Gustavo Düring (New York University)
    Vendredi 7 septembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    A unified framework for non-Brownian suspension flows and soft amorphous solids
    While the rheology of non-Brownian suspensions in the dilute regime is well-understood, their behavior in the dense limit remains mystifying. As the packing fraction of particles increases, particle motion becomes more collective, leading to a growing length scale and scaling properties in the rheology as the (...)
  • Gustavo Düring (New York University)
    Vendredi 7 septembre 2012 de 11h00 à 12h00 - Bureau d'Etudes
    A unified framework for non-Brownian suspension flows and soft amorphous solids
    While the rheology of non-Brownian suspensions in the dilute regime is well-understood, their behavior in the dense limit remains mystifying. As the packing fraction of particles increases, particle motion becomes more collective, leading to a growing length scale and scaling properties in the rheology as the (...)
  • Marcelo Dias (University of Massachusetts, Amherst)
    Vendredi 13 juillet 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Folding as a Mechanism of 3D Shape Formation in Thin Elastic Sheets
    Folding a sheet of paper along a curve can lead to structures seen in decorative art and utilitarian packing boxes. Here we present a theory for the simplest such structure : an annular circular strip that is folded along a central circular curve to form a three-dimensional buckled structure driven by geometrical (...)
  • Marcelo Dias (University of Massachusetts, Amherst)
    Vendredi 13 juillet 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Folding as a Mechanism of 3D Shape Formation in Thin Elastic Sheets
    Folding a sheet of paper along a curve can lead to structures seen in decorative art and utilitarian packing boxes. Here we present a theory for the simplest such structure : an annular circular strip that is folded along a central circular curve to form a three-dimensional buckled structure driven by geometrical (...)
  • Guadalupe Huelsz (Centro de Investigación en Energía, UNAM)
    Vendredi 6 juillet 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Thermal confort and energy in buildings
    A broad view of the researches carried out by the Building Energy Group at the Centro de Investigación en Energía of the Universidad Nacional Autónoma de México is presented. These researches go from basic studies on heat and mass transfer in laboratory experiments and numerical simulations, to applied studies for the (...)
  • Guadalupe Huelsz (Centro de Investigación en Energía, UNAM)
    Vendredi 6 juillet 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Thermal confort and energy in buildings
    A broad view of the researches carried out by the Building Energy Group at the Centro de Investigación en Energía of the Universidad Nacional Autónoma de México is presented. These researches go from basic studies on heat and mass transfer in laboratory experiments and numerical simulations, to applied studies for the (...)
  • Ulrich Tallarek (Philipps-Universität Marburg)
    Vendredi 29 juin 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Physical Reconstruction and Morphological Analysis of Granular and Monolithic Materials : From Metric Properties to Structural Descriptors of Diffusion and Hydrodynamic Dispersion
    The discovery of the morphology-transport relationships for chromatographic media (packed and monolithic beds, confined pillar structures) belongs to the major challenges in separation science, because it requires the 3D physical reconstruction and/or computer-generation of the media followed by 3D mass transport (...)
  • Ulrich Tallarek (Philipps-Universität Marburg)
    Vendredi 29 juin 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Physical Reconstruction and Morphological Analysis of Granular and Monolithic Materials : From Metric Properties to Structural Descriptors of Diffusion and Hydrodynamic Dispersion
    The discovery of the morphology-transport relationships for chromatographic media (packed and monolithic beds, confined pillar structures) belongs to the major challenges in separation science, because it requires the 3D physical reconstruction and/or computer-generation of the media followed by 3D mass transport (...)
  • Elisabeth Guazzelli (IUSTI, Marseille)
    Vendredi 22 juin 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Bed-load transport : experimental observation and two-phase modeling
    The erosion of granular beds under the action of fluid shearing flows is a problem which has been continuously studied and discussed for over a century. This phenomenon is indeed encountered in a wide range of processes of important relevance in nature or industry such as sediment transport in rivers or oceans and (...)
  • Pedro M. Reis (MIT)
    Vendredi 15 juin 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Geometry-induced rigidity, failure and functionality in thin elastic structures
    I will present recent results from our Laboratory on the mechanical behavior of complex-shaped shells, subjected to different forms of loading. The common underlying feature in these problems is the prominence of geometry in dictating the mechanical response in slender elastic objects. Our approach in primarily (...)
  • James Hanna (University of Massachusetts, Amherst)
    Vendredi 8 juin 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Strings in Motion
    The statics and dynamics of thin strings are a classical subject in mechanics, and form the core of many open problems in geometrically nonlinear elasticity. I will begin by discussing what catenaries and lariats have in common, then present new results on rotating strings. With simple examples, I will illustrate (...)
  • Alexis Peaucelle (INRA, Versailles)
    Vendredi 1er juin 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Hypocotyl growth : Could you do anisotropical growth with isotropic material ?
    Siobhan Braybrook, Herman Hoft, Alexis Peaucelle To escape from the globular shape pluricellular organism have to develop locale tissue polar growth else named as anisotropicale growth. The axially organisation of plants is one of the best example. This ability of plants for astonishing anisotropical growth is (...)
  • Arezki Boudaoud (ENS Lyon)
    Vendredi 25 mai 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Bases physiques de la morphogenèse végétale : bruit et robustesse
    La morphogenèse est le processus de construction de la forme et de l'architecture d'un être vivant lors de son développement. La forme étant imposée par des éléments structuraux, il est naturel d'étudier les propriétés mécaniques des cellules et des tissus. Quels sont alors les principes physiques de la morphogenèse ? Par (...)
  • Marco Rivetti (Institut Jean le Rond d'Alembert)
    Vendredi 11 mai 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Deux problèmes d'interaction élasto-capillaire
    La force capillaire est responsable de la forme d'une goutte d'eau, d'une bulle de savon, d'une interface liquide-gaz proche d'une paroi solide et bien d'autres phénomènes. Dans certaines configurations, et en particulier aux petites échelles, cette force peut être suffisamment intense pour induire des déformations (...)
  • Renaud Bastien (INRA)
    Vendredi 4 mai 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Cinématique et Modélisation du Mouvement Gravitropique des Tiges Végétales
    Pour pouvoir se redresser par rapport à la gravité et maintenir une posture érigée, les plantes déploient des mouvements complexes permettant une réorientation active de leurs différents organes. De nombreuses études se sont attachées à décrire les mécanismes précurseurs de la réaction ainsi que les mécanismes physiologiques, (...)
  • Jérôme Fresnais (PECSA, UMR 7195 CNRS UPMC ESPCI)
    Vendredi 27 avril 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Electrostatic co-assembly between magnetic nanoparticles and hydrophilic to amphiphilic polymers
    Les nanoparticules magnétiques sont le sujet de nombreuses études depuis leur synthèse dans les années 80, notamment par l'équipe du professeur Massart qui en a décrit une synthèse dite douce. Leur caractère superparamagnétique leur confère des propriétés d'agent de contraste en IRM, ainsi que comme agent de vectorisation (...)
  • Jacques Pelegrin (Maison de l'Ethnologie et de l'Archéologie, Université Paris Ouest-Nanterre )
    Vendredi 13 avril 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Techniques de taille préhistoriques du silex et de verre volcanique (obsidienne) par fracture conchoïdale
    Résumé : Spécialiste de technologie lithique préhistorique et expérimentateur, J. Pelegrin propose d'illustrer diverses techniques développées pendant la Préhistoire pour la taille de l'obsidienne et du silex (percussion directe à la pierre et au bois, percussion indirecte, pression). La fracture conchoïdale -l'un des (...)
  • Nadia Sénéchal (EPOC, Université de Bordeaux I)
    Vendredi 6 avril 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Morphodynamique des plages sableuses : de l'événementiel au saisonnier
    Résumé : Le littoral, interface entre la mer et le continent émergé, ne peut plus être considéré de nos jours comme une zone tampon. La forte pression socio-démographique et économique qui s'y exerce, le rend vulnérable en particulier à toute fluctuation de la position du trait de côte en relation avec les (...)
  • Ramón Peralta y Fabi (Universidad Nacional Autónoma de México)
    Vendredi 30 mars 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Thermal Convection in 2D with Varying Gravity
    A study of convection in a two dimensional cell is presented. A newtonian homogeneous fluid is contained between two parallel circular glass plates (10 cm diameter) separated a small distance (1mm). Gravity can be varied by changing the inclination of the cell. The system is heated and cooled at two diametrically (...)
  • Elisabeth Bouchaud (EC2M, UMR Gulliver, ESPCI)
    Vendredi 23 mars 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Stress corrosion fracture of glass
    Although amorphous silica has a liquid-like homogeneous structure at length scales as short as ∼10 Å, it seems to behave as a disordered material when fractured. Controversial Atomic Force Microscopy experiments have indeed suggested that a stress corrosion crack – which progresses very slowly under the combined (...)
  • Cyprien Gay (MSC)
    Vendredi 9 mars 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Excursions dans la rhéologie d'une mousse liquide
    Résumé : Une mousse liquide est élastique aux temps courts mais se réarrange et flue aux temps longs sous faible contrainte, comme un liquide. Aux temps intermédiaires, une contrainte modérée déclenche un fluage forcé (comportement plastique). Nous explorerons, principalement en images, quelques ingrédients des (...)
  • Cyprien Gay (MSC)
    Vendredi 9 mars 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Excursions dans la rhéologie d'une mousse liquide
    Résumé : Une mousse liquide est élastique aux temps courts mais se réarrange et flue aux temps longs sous faible contrainte, comme un liquide. Aux temps intermédiaires, une contrainte modérée déclenche un fluage forcé (comportement plastique). Nous explorerons, principalement en images, quelques ingrédients des (...)
  • Xavier Garnaud (LadHyX, École Polytechnique)
    Vendredi 24 février 2012 de 11h00 à 12h00 - A1 (Urbain)
    Global instabilities of subsonic jets
    The stability of spatially developing subsonic jets is investigated. If the density ratio between the jet and the outside is sufficiently low, arbitrarily small perturbations grow in time until self sustained oscillation appear in the non-linear regime. Both the apparition of these structures and their frequency (...)
  • Xavier Garnaud (LadHyX, École Polytechnique)
    Vendredi 24 février 2012 de 11h00 à 12h00 - A1 (Urbain)
    Global instabilities of subsonic jets
    The stability of spatially developing subsonic jets is investigated. If the density ratio between the jet and the outside is sufficiently low, arbitrarily small perturbations grow in time until self sustained oscillation appear in the non-linear regime. Both the apparition of these structures and their frequency (...)
  • Gerardo Ruíz Chavarría (Universidad Nacional Autonoma de México)
    Vendredi 17 février 2012 de 11h00 à 12h00 - A5 (Holweck)
    Vorticité et transport de particules dans un écoulement avec forçage périodique
    Dans cet exposé on présente des résultats numériques et expérimentaux concernant l'écoulement dans un système formé par un canal connecté à un domaine ouvert avec un débit variable. Ce type d'écoulement apparait par exemple entre une lagune intérieure connectée à la mer à travers un canal sous l'action des marées. La dynamique (...)
  • Gerardo Ruíz Chavarría (Universidad Nacional Autonoma de México)
    Vendredi 17 février 2012 de 11h00 à 12h00 - A5 (Holweck)
    Vorticité et transport de particules dans un écoulement avec forçage périodique
    Dans cet exposé on présente des résultats numériques et expérimentaux concernant l'écoulement dans un système formé par un canal connecté à un domaine ouvert avec un débit variable. Ce type d'écoulement apparait par exemple entre une lagune intérieure connectée à la mer à travers un canal sous l'action des marées. La dynamique (...)
  • Guillermo Artana (Universidad de Buenos Aires) & Denisse Sciamarella (LIMSI)
    Vendredi 10 février 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Auto-similarité dans les plans de symétrie d'un jet pulsé quasi-elliptique
    Dans cette présentation on montre que le concept d'auto-similarité d'habitude utilisé dans des écoulements axisymétrique ou bidimensionnels peut être étendu pour des jets 3D qui présentent des axes de symétrie. Ainsi l'analyse d'auto-similarité devient possible pour un jet quasi-elliptique à condition de borner l'étude aux (...)
  • Guillermo Artana (Universidad de Buenos Aires) & Denisse Sciamarella (LIMSI)
    Vendredi 10 février 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Auto-similarité dans les plans de symétrie d'un jet pulsé quasi-elliptique
    Dans cette présentation on montre que le concept d'auto-similarité d'habitude utilisé dans des écoulements axisymétrique ou bidimensionnels peut être étendu pour des jets 3D qui présentent des axes de symétrie. Ainsi l'analyse d'auto-similarité devient possible pour un jet quasi-elliptique à condition de borner l'étude aux (...)
  • Hervé le Bras (Lab. de Démographie Historique, CNRS-EHESS)
    Vendredi 3 février 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Le principe d'incertitude en démographie
    comparaison des projections démographiques avec ce qui s'est réellement produit. L'origine des ratages : fixation sur le passé proche, idéologie, self-fullfilling and non-self-fullfilling prophecies, points de retournement. Peut-on prévoir les points de retournement ? quelques exemples. Variations des causes avec (...)
  • Rémy Colin (MSC - Paris Diderot )
    Vendredi 20 janvier 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Dynamique hétérogène dans des verres de colloïdes thermosensibles
    Quand un liquide est refroidi suffisamment rapidement en dessous de sa température de solidification, sa cristallisation peut être évitée au profit de la formation d'un solide désordonné et hors équilibre appelé verre. Les suspensions colloïdales présentent un comportement analogue (formation d'un solide désordonné et hors (...)
  • Guillaume Romet-Lemonne (LEBS, Gif-sur-Yvette)
    Vendredi 13 janvier 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Studying the dynamics of individual actin filaments using microfluidics
    Actin filaments are an essential part of the cytoskeleton, and drive various cell processes, during which they elongate, disassemble and form different architectures. Actin filament assembly is itself a complex mechanism, in which ATP-bound actin monomers are incorporated into filaments, where they hydrolyze their (...)
  • Charles Baroud (LadHyX, École Polytechnique)
    Vendredi 6 janvier 2012 de 11h00 à 12h00 - Bureau d'Etudes
    Deux histoires courtes pour se déplacer dans un microcanal
    Résumé : J'aborderai deux thèmes sur lesquels nous avons travaillé récemment : D'abord je montrerai la manipulation de gouttes microfluidiques en deux dimensions, en utilisant les gradients d'énergie de surface. Cette technique que nous avons appelée "rails and anchors" permet de créer des matrices de gouttes pour les (...)

• 2011

  • Francesc Sagués (Universitat de Barcelona)
    Vendredi 9 décembre 2011 de 11h00 à 12h00 - A4 (Langevin)
    Séminaire PMMH
    Driven paramagnetic colloids : from ratchets to swimmers I will briefly review some recent experimental and theoretical work on driven paramagnetic colloids either dispersed on structured or unstructured supports. In the first part the realization of modes of discrete transport of particles on patterned magnetic (...)
  • Björn Hof (Max Planck Institute for Dynamics and Self-Organization, Göttingen)
    Vendredi 2 décembre 2011 de 11h00 à 13h30 - A4 (Langevin)
    Turbulence in pipe flow
    Séminaires du laboratoire PMMH : consultez le programme
  • Pascal Panizza (Université de Rennes I )
    Vendredi 18 novembre 2011 de 11h00 à 12h00 - Amphithéâtre Langevin
    Trafic et fragmentation de gouttes en microfluidique
    Les techniques récentes de microfluidique permettent de produire des gouttelettes monodisperses de manière contrôlée et de les manipuler individuellement. Utilisées comme microréacteurs, ces gouttelettes sont l'élément de base d'applications digitales haut-débit permettant d'analyser un processus cinétique très rapidement, (...)

• • Séminaire PMMH - Thomas Paehtz (Zhejiang University)
    

    Unified model of sediment transport threshold and rate across subaqueous bedload, windblown sand, and windblown snow

    Loose sedimentary grains cover much of the wind-blown (i.e., aeolian) and water-worked (i.e., fluvial) sedimentary surfaces of Earth and other planetary bodies. To predict how su(...)
    Unified model of sediment transport threshold and rate across subaqueous bedload, windblown sand, and windblown snow
    Loose sedimentary grains cover much of the wind-blown (i.e., aeolian) and water-worked (i.e., fluvial) sedimentary surfaces of Earth and other planetary bodies. To predict how such surfaces evolve in response to aeolian and fluvial flows, one needs to understand the rate at which sediment is transported for given (...)

  • Séminaire PMMH - Philippe Gondret (FAST, Univ. Paris-Saclay)
    

    Tsunami generation by landslides : From laboratory experiments to geophysical events

    Tsunami waves can arise from significant geological events such as the collapse of a mountain flank or a volcano into a lake or an ocean. We reproduce this situation at the laboratory scale. The landslide is mo(...)
    Tsunami generation by landslides : From laboratory experiments to geophysical events
    Tsunami waves can arise from significant geological events such as the collapse of a mountain flank or a volcano into a lake or an ocean. We reproduce this situation at the laboratory scale. The landslide is modeled by the sudden release of a rectangular granular column, which then impacts a still water layer and (...)

  • Séminaire PMMH - Jérémy Hure (CEA Saclay)
    

    Plasticity and ductile fracture in irradiated metals

    Metals used in nuclear reactors core are subjected to neutron irradiation, leading to different kind of crystallographic defects depending on irradiation conditions. The main irradiation defects include dislocation loops and nano-voids. These(...)
    Plasticity and ductile fracture in irradiated metals
    Metals used in nuclear reactors core are subjected to neutron irradiation, leading to different kind of crystallographic defects depending on irradiation conditions. The main irradiation defects include dislocation loops and nano-voids. These defects have a strong influence on plasticity mechanisms, and, in turn, (...)

  • Séminaire PMMH - Matilda Backholm (Aalto Univ., Helsinki, Finland)
    

    When honey moves faster than water

    The viscosity of a fluid is well known to limit its flow : the more viscous a droplet, the slower it moves [1,2]. Here, we show that this intuitive rule breaks down in a confined liquid-repellent geometry. A gravity-driven, highly viscous glycerol droplet plac(...)
    When honey moves faster than water
    The viscosity of a fluid is well known to limit its flow : the more viscous a droplet, the slower it moves [1,2]. Here, we show that this intuitive rule breaks down in a confined liquid-repellent geometry. A gravity-driven, highly viscous glycerol droplet placed in a sealed superhydrophobic capillary moves more (...)

  • Séminaire PMMH - Emmanuelle Rio (LPS-Univ. Paris Saclay)
    

    Rupture of Foam Films and Surface Bubbles

    Surface bubbles are of crucial interest since they favours the transport of material from the bulk to the overlying atmosphere through the production of aerosols. This is important for example in climate models, air pollution studies or in the carbonate(...)
    Rupture of Foam Films and Surface Bubbles
    Surface bubbles are of crucial interest since they favours the transport of material from the bulk to the overlying atmosphere through the production of aerosols. This is important for example in climate models, air pollution studies or in the carbonated beverage industry since the produced aerosols contain most (...)

  • Séminaire PMMH - Baptiste Darbois-Texier (FAST)
    

    Surface instability of shear-thickening suspensions down an inclined plane

    A shear-thickening suspension, such as cornstarch particles in water, exhibits a very strange behavior : it flows as milk when gently stirred but turns rock solid under impact. Despite its notoriety, this phenomenon has(...)
    Surface instability of shear-thickening suspensions down an inclined plane
    A shear-thickening suspension, such as cornstarch particles in water, exhibits a very strange behavior : it flows as milk when gently stirred but turns rock solid under impact. Despite its notoriety, this phenomenon has been understood only recently. Based on this progress, we decided to explore the behavior of (...)

  • Séminaire PMMH - Chung-Yuen Hui (Cornell University)
    

    Mechanical Properties of Fiber-Reinforced Soft Composites

    In this talk I will focus on an emerging class of fiber reinforced composites where the matrix is extremely soft and tough. For example, an upper estimate for fiber/matrix modulus ratio in traditional fiber reinforced polymer composites (...)
    Mechanical Properties of Fiber-Reinforced Soft Composites
    In this talk I will focus on an emerging class of fiber reinforced composites where the matrix is extremely soft and tough. For example, an upper estimate for fiber/matrix modulus ratio in traditional fiber reinforced polymer composites is at most 100. Matrices made from tough elastic gels can have modulus (...)

  • Séminaire PMMH, Arthur Lebée ENPC
    

    Continuum elasticity of Miura Tessellations

    Origami tessellations are curved two-dimensional discrete shells folded out of a periodic crease pattern. Unlike solid shells, Origami tessellations can morph and access a space of configurations each characterized by the list of folding angles of all(...)
    Continuum elasticity of Miura Tessellations
    Origami tessellations are curved two-dimensional discrete shells folded out of a periodic crease pattern. Unlike solid shells, Origami tessellations can morph and access a space of configurations each characterized by the list of folding angles of all creases. Due to inextensibility constraints imposed by Origami (...)

  • Séminaire PMMH - Doron Grossman (Collège de France)
    

    From Molecules to Helical Ribbons - Shape and Shape Fluctuations

    *

    Self assembly of molecules into supramolecular structures is an important process through which non trivial structures are formed in nano-metric scale. The resulting structure depends on chemical and physical principles t(...)
    From Molecules to Helical Ribbons - Shape and Shape Fluctuations
    * Self assembly of molecules into supramolecular structures is an important process through which non trivial structures are formed in nano-metric scale. The resulting structure depends on chemical and physical principles that govern the process, and may be sensitive to the exact conditions in which they are (...)

  • Séminaire PMMH - Séverine Atis (Harvard University)
    

    On Growth and Form of Range Expansions at Liquid Interfaces

    Range expansions coupled with fluid flows are of great importance in understanding the organization and competition of microorganism populations in liquid environments. However, combining growth dynamics of an expanding assembly of cel(...)
    On Growth and Form of Range Expansions at Liquid Interfaces
    Range expansions coupled with fluid flows are of great importance in understanding the organization and competition of microorganism populations in liquid environments. However, combining growth dynamics of an expanding assembly of cells with hydrodynamics leads to challenging problems, involving the coupling of (...)

  • Séminaire PMMH -Julien Bobroff (LPS, Univ. Paris-Sud/Paris-Saclay)
    

    La physique autrement

    Pourquoi vulgariser la physique autrement ? Et surtout comment ? Voilà les deux questions au coeur des activités de notre équipe de recherche. Nous y explorons de nouvelles formes de vulgarisation en lien avec le monde du design et de la création. Parmi nos dernières (...)
    La physique autrement
    Pourquoi vulgariser la physique autrement ? Et surtout comment ? Voilà les deux questions au coeur des activités de notre équipe de recherche. Nous y explorons de nouvelles formes de vulgarisation en lien avec le monde du design et de la création. Parmi nos dernières productions, un objet de médiation sur la (...)

  • Séminaire PMMH - Patrick Bot (Institut de Recherche de l'Ecole Navale)
    

    From sails aerodynamics to the Lift Crisis (and other results on the lift generated by a highly curved plate)

    Yacht sails show some peculiarities among aerodynamic systems. Rather flat sails are used to sail upwind, and the flow remains mostly attached. To sail downwind, highly cambered sails m(...)
    From sails aerodynamics to the Lift Crisis (and other results on the lift generated by a highly curved plate)
    Yacht sails show some peculiarities among aerodynamic systems. Rather flat sails are used to sail upwind, and the flow remains mostly attached. To sail downwind, highly cambered sails may be used where flow separation is significant. Some results will be shown on the flow around a spinnaker and the related fluid (...)

  • Séminaire PMMH - Farzam Zoueshtiagh (IEMN, Lille)
    

    Dynamics and stability of a liquid-gas interface in the presence of micro-particles

    [\This French-Japan-US collaborative study examines the influence of the micro-particles on the stability of the liquid-air interface. We will first revisit the effect of these particles on the dynamics of the i(...)
    Dynamics and stability of a liquid-gas interface in the presence of micro-particles
    [\This French-Japan-US collaborative study examines the influence of the micro-particles on the stability of the liquid-air interface. We will first revisit the effect of these particles on the dynamics of the interface in a confined "1D" geometry [1] with the formation of armored bubbles (fig. 1(a)) and will show (...)

  • Séminaire PMMH - Allbens Atman (Centro Federal de Educação Tecnológica de Minas Gerais, Brasil)
    

    Experimental validation of nonextensive scaling law in confined granular media : emergence of shear bands

    The statistics of grain displacements probability distribution function (pdf) during the shear of a granular medium displays an unusual dependence with the shear increment upscaling as rece(...)
    Experimental validation of nonextensive scaling law in confined granular media : emergence of shear bands
    The statistics of grain displacements probability distribution function (pdf) during the shear of a granular medium displays an unusual dependence with the shear increment upscaling as recently evinced [Phys. Rev. Lett. 115 238301 2015]. Basically, the pdf of grain displacements has clear nonextensive (q-Gaussian) (...)

  • Séminaire PMMH - Denis Guthleben (CNRS)
    

    Le CNRS, 80... et quelques années d'histoire

    Créé par un décret du 19 octobre 1939, le CNRS voit le jour dans un monde qui vient de basculer dans l'abîme : six semaines plus tôt, l'Allemagne nazie a envahi la Pologne et, dans la foulée, l'Angleterre et la France lui ont déclaré la guer(...)
    Le CNRS, 80... et quelques années d'histoire
    Créé par un décret du 19 octobre 1939, le CNRS voit le jour dans un monde qui vient de basculer dans l'abîme : six semaines plus tôt, l'Allemagne nazie a envahi la Pologne et, dans la foulée, l'Angleterre et la France lui ont déclaré la guerre. Dans ce contexte, le nouvel établissement doit piloter la mobilisation (...)

  • Séminaire PMMH - Michaël Baudoin (IEMN - Université de Lille)
    

    Manipulation of fluid and particles at microscales with selective acoustical tweezers

    The selective contactless manipulation and assembly of physical and biological objects and fluids at micrometric down to nanometric scales promises tremendous development in fields as diverse as microrobotics,(...)
    Manipulation of fluid and particles at microscales with selective acoustical tweezers
    The selective contactless manipulation and assembly of physical and biological objects and fluids at micrometric down to nanometric scales promises tremendous development in fields as diverse as microrobotics, microfluidics, tissue engineering or micro/nano- medicine. In this regard, acoustical tweezers is a (...)

  • Séminaire PMMH - Shreyas Mandre (Brown Univ., Providence)
    

    Surfactants driven out of equilibrium by a flow

    A surfactant is a chemical compound that adsorbs onto a fluid-fluid interface and reduces its surface tension. A non-uniform distribution of such compounds at the interface causes a Marangoni stress that drives a flow, which in turn transports the(...)
    Surfactants driven out of equilibrium by a flow
    A surfactant is a chemical compound that adsorbs onto a fluid-fluid interface and reduces its surface tension. A non-uniform distribution of such compounds at the interface causes a Marangoni stress that drives a flow, which in turn transports the surfactant. Estimating in situ the degree to which the adsorbed (...)

  • Séminaire PMMH - Tobias Schneider (EPFL)
    

    A network of invariant solutions underlying spatio-temporal patterns in inclined layer convection

    Thermal convection in a fluid between two horizontal plates, a lower hot plate and an upper cold plate, exhibits chaotic dynamics and turbulence. If such a convection cell is inclined against gravi(...)
    A network of invariant solutions underlying spatio-temporal patterns in inclined layer convection
    Thermal convection in a fluid between two horizontal plates, a lower hot plate and an upper cold plate, exhibits chaotic dynamics and turbulence. If such a convection cell is inclined against gravity, buoyancy forces drive hot and cold fluid up and down the incline leading to a shear flow in the base state and the (...)

  • Séminaire PMMH - Marie Le Merrer (ILM, Univ. Lyon 1)
    

    Flow and surfactant dynamics in bubble rearrangements in foams

    Liquid foams are assemblies of gas bubbles in a soapy solution, found in many applications from cosmetics to oil drilling. The nature of surfactants changes the properties of the liquid-gas interfaces, and consequently the macroscop(...)
    Flow and surfactant dynamics in bubble rearrangements in foams
    Liquid foams are assemblies of gas bubbles in a soapy solution, found in many applications from cosmetics to oil drilling. The nature of surfactants changes the properties of the liquid-gas interfaces, and consequently the macroscopic properties of the foam like its stability and rheology. However, the flow (...)

  • Séminaire PMMH - Bernadette Bensaude-Vincent (Univ. Paris 1)
    

    Dialogue avec les matériaux

    Cette intervention est une invite à penser les matériaux comme des partenaires de nos aventures techniques. Après un bref historique des conditions d'émergence de la science des matériaux on montrera en quel sens les matériaux sont des hybrides de nature, de t(...)
    Dialogue avec les matériaux
    Cette intervention est une invite à penser les matériaux comme des partenaires de nos aventures techniques. Après un bref historique des conditions d'émergence de la science des matériaux on montrera en quel sens les matériaux sont des hybrides de nature, de technique et de société. Et on illustrera cette condition (...)

  • Séminaire PMMH - Emmanuel Virot (EPFL - Harvard University)
    

    Non-destructive prediction of the buckling load of soda cans and space rockets

    What is the critical load required to crush a soda can or a space rocket shell ? Surprisingly, there is no good way to estimate it, because of the high defect-sensitivity of the buckling instability. Here we measure (...)
    Non-destructive prediction of the buckling load of soda cans and space rockets
    What is the critical load required to crush a soda can or a space rocket shell ? Surprisingly, there is no good way to estimate it, because of the high defect-sensitivity of the buckling instability. Here we measure the response of (imperfect) empty Coca-Cola cans to lateral poking and identify a generic stability (...)

  • Séminaire PMMH - Pierre Jop (SVI, Saint-Gobain)
    

    Vers un matériau granulaire humide : quand la capillarité contrôle les interfaces

    Le mélange de grains avec un liquide est souvent la première étape d'un processus industriel, mais la nature triphasique du milieu rend la description globale difficile [1] : la cohésion des ponts capillair(...)
    Vers un matériau granulaire humide : quand la capillarité contrôle les interfaces
    Le mélange de grains avec un liquide est souvent la première étape d'un processus industriel, mais la nature triphasique du milieu rend la description globale difficile [1] : la cohésion des ponts capillaires [2] et la progression du liquide dans le système créent des zones de comportements mécaniques différents. De (...)

  • Séminaire PMMH - Mark Pauly (EPFL)
    

    Light, Matter, Form - Computational Design of Functional Geometry

    In this talk, I will outline a general computational approach for material-aware design of complex 3D models. The key step is to identify suitable geometric abstractions of physical properties that enable effective computations w(...)
    Light, Matter, Form - Computational Design of Functional Geometry
    In this talk, I will outline a general computational approach for material-aware design of complex 3D models. The key step is to identify suitable geometric abstractions of physical properties that enable effective computations with high predictive accuracy. I will show several examples of this approach for (...)

  • Séminaire PMMH - Laurent Duchemin (IRPhE, Marseille)
    

    Deux écoulements capillaires impulsionnels

    Dans cet exposé, je présenterai deux études expérimentales et théoriques sur des écoulements ayant une dynamique rapide à une échelle capillaire.

    La première concerne l'étirement impulsionnel d'un ligament liquide millimétrique. Dans(...)
    Deux écoulements capillaires impulsionnels
    Dans cet exposé, je présenterai deux études expérimentales et théoriques sur des écoulements ayant une dynamique rapide à une échelle capillaire. La première concerne l'étirement impulsionnel d'un ligament liquide millimétrique. Dans le contexte général de la fragmentation, cette expérience modèle permet à la fois d'étudier (...)

  • Séminaire PMMH - Marc Durand (MSC, Univ. Paris Diderot)
    

    Milieux cellulaires fluides et réseaux : microstructure et propriétés effectives

    Les propriétés structurelles (géométrie, topologie, désordre) d'un matériau à l'échelle de ses constituants affectent profondément ses propriétés effectives, telles que sa réponse mécanique ou acous(...)
    Milieux cellulaires fluides et réseaux : microstructure et propriétés effectives
    Les propriétés structurelles (géométrie, topologie, désordre) d'un matériau à l'échelle de ses constituants affectent profondément ses propriétés effectives, telles que sa réponse mécanique ou acoustique. Au cours de ce séminaire, je présenterai diverses études visant à caractériser - de manière exacte ou statistique - les (...)

  • Séminaire PMMH : Thomas Engels (LMD, ENS)
    

    The impact of turbulence on flying insects in tethered and free flight : high-resolution numerical experiments

    Flapping insects are remarkably agile fliers, adapted to a highly turbulent environment. We present a series of high resolution numerical simulations of a bumblebee interacting with fu(...)
    The impact of turbulence on flying insects in tethered and free flight : high-resolution numerical experiments
    Flapping insects are remarkably agile fliers, adapted to a highly turbulent environment. We present a series of high resolution numerical simulations of a bumblebee interacting with fully developed turbulent inflow. We consider both tethered and free flight, the latter with all six degrees of freedom coupled to (...)

  • Séminaire PMMH - Hans Herrmann (ETH, Zürich)
    

    Structures granulaires renforcées par un fil et éjections granulaires d'un milieu poreux

    Je vais présenter deux sujets granulaires :

    Le premier c'est la stabilisation d'une colonne granulaire avec un fil. Il s'agit de comprendre avec des expériences et des simulations numériques pou(...)
    Structures granulaires renforcées par un fil et éjections granulaires d'un milieu poreux
    Je vais présenter deux sujets granulaires : Le premier c'est la stabilisation d'une colonne granulaire avec un fil. Il s'agit de comprendre avec des expériences et des simulations numériques pourquoi et comment stabilisent des piliers renforcés par ficelle selon une nouvelle technique développée par des architectes. (...)

  • Séminaire PMMH - Fernando Peruani (Univ. de Nice)
    

    Towards a non-equilibrium statistical mechanics of biological and biomimetic systems

    Collective phenomena are observed in biological and biomimetic systems at all scales, from bacterial systems to sheep herds in biology, and from Quincke rollers to bristlebots or kilobots in man-made, active sy(...)
    Towards a non-equilibrium statistical mechanics of biological and biomimetic systems
    Collective phenomena are observed in biological and biomimetic systems at all scales, from bacterial systems to sheep herds in biology, and from Quincke rollers to bristlebots or kilobots in man-made, active systems. Provided that these non-equilibrium systems consist of independent units without a central control (...)

  • Séminaire PMMH - Federico Toschi (Technische Universiteit, Eindhoven)
    

    Turbulence and plastic events in fluid emulsions

    Emulsions made of immiscible fluids can display an very rich phenomenology. In this talk we will discuss how to numerically model fluid emulsions and we will present results from recent numerical studies. The numerical model that we employ is bas(...)
    Turbulence and plastic events in fluid emulsions
    Emulsions made of immiscible fluids can display an very rich phenomenology. In this talk we will discuss how to numerically model fluid emulsions and we will present results from recent numerical studies. The numerical model that we employ is based on the multi-component Lattice Boltzmann method as it provides a (...)

  • Séminaire PMMH - Alexander Alexeev (Georgia Tech)
    

    Biomimetic flapping and beating in viscous fluid

    We probe interactions of elastic structures with viscous fluids to investigate biomimetic approaches for fluid manipulation. We consider two systems : fish-like elastic fines and artificial cilia. Fish displays incredible agility and speed using (...)
    Biomimetic flapping and beating in viscous fluid
    We probe interactions of elastic structures with viscous fluids to investigate biomimetic approaches for fluid manipulation. We consider two systems : fish-like elastic fines and artificial cilia. Fish displays incredible agility and speed using oscillating flexible fins. We represent fins as thin elastic plates (...)

  • Séminaire PMMH - Giuseppe Zurlo (National University of Ireland)
    

    Manufacturing of information-rich elastic bodies through surface deposition.

    In this talk I will discuss a recent theory, developed in collaboration with Lev Truskinovsky, that describes how desired distributions of residual stress can be achieved in bodies that are manufactured though the loc(...)
    Manufacturing of information-rich elastic bodies through surface deposition.
    In this talk I will discuss a recent theory, developed in collaboration with Lev Truskinovsky, that describes how desired distributions of residual stress can be achieved in bodies that are manufactured though the local addition of mass on their boundary [1],[2]. The source of residual stresses in elastic bodies (...)

  • Séminaire PMMH - Sébastien Neukirch (Institut d'Alembert, Sorbonne Université)
    

    Le treuil élastocapillaire en une et deux dimensions

    Nous parlerons d'élasto-capillarité, domaine mêlant la déformation des structures élastiques et les forces de tension de surface. En effet, les forces capillaires que développent les gouttes liquides peuvent être suffisamment intenses(...)
    Le treuil élastocapillaire en une et deux dimensions
    Nous parlerons d'élasto-capillarité, domaine mêlant la déformation des structures élastiques et les forces de tension de surface. En effet, les forces capillaires que développent les gouttes liquides peuvent être suffisamment intenses pour plier des filaments ou des membranes, voire même enrouler des fibres. Plus (...)

  • Séminaire PMMH - Matthieu Roché (MSC, Univ. Paris Diderot)
    

    Effet Marangoni induit par des tensioactifs solubles

    La présence d'un gradient thermique ou d'un gradient de concentration de surface en molécules tensioactives le long d'une interface entre deux liquides conduit à l'existence d'un gradient de tension interfaciale et à l'établissement d'un(...)
    Effet Marangoni induit par des tensioactifs solubles
    La présence d'un gradient thermique ou d'un gradient de concentration de surface en molécules tensioactives le long d'une interface entre deux liquides conduit à l'existence d'un gradient de tension interfaciale et à l'établissement d'un écoulement dans le volume de chaque liquide : c'est l'effet Marangoni, thermique (...)

  • Séminaire PMMH - Hiroaki Katsuragi (Nagoya University)
    

    Solid projectile impact onto a porous dust aggregate consisting of micrometer-sized particles

    Porous dust aggregates consisting cohesive monomer grains are considered materials to build planetesimals in a protoplanetary disk. In order to reveal the history of planet formation, mechanical proper(...)
    Solid projectile impact onto a porous dust aggregate consisting of micrometer-sized particles
    Porous dust aggregates consisting cohesive monomer grains are considered materials to build planetesimals in a protoplanetary disk. In order to reveal the history of planet formation, mechanical properties of dust aggregates have to be quantitatively understood. In this study, we perform a simple impact experiment (...)

  • Séminaire PMMH : Jean-Pierre Hulin (FAST, Orsay)
    

    Tracer spreading at low Reynolds numbers : reversible or not ?

    The reversibility of fluid velocity fields at low Reynolds numbers with respect to a change of the flow direction is well established : its may result in the reversibility of tracer spreading and mixing as may be demonstrated specta(...)
    Tracer spreading at low Reynolds numbers : reversible or not ?
    The reversibility of fluid velocity fields at low Reynolds numbers with respect to a change of the flow direction is well established : its may result in the reversibility of tracer spreading and mixing as may be demonstrated spectacularly in simple geometries such as Couette flows. However, at long times, this (...)

  • Séminaire PMMH - Wilson Poon (The University of Edinburgh, UK)
    

    Complexity and decay — towards a science of self disassembly

    Soft matter physics has been obsessed with 'self assembly' for some time - the ability of Brownian or, more recently, 'active matter' systems to generate (sometimes useful !) patterns 'on their own accord'. The original impulse for (...)
    Complexity and decay — towards a science of self disassembly
    Soft matter physics has been obsessed with 'self assembly' for some time - the ability of Brownian or, more recently, 'active matter' systems to generate (sometimes useful !) patterns 'on their own accord'. The original impulse for this was biological, the term 'self assembly' being first used in a famous 1962 (...)

  • Séminaire PMMH : Timothée Mouterde (LPS, ENS))
    

    Matériaux multifonctions : antipluie, antibuée, antireflets

    Sur une surface couverte de microrugosités hydrophobes, l'eau est ultra-mobile. Ces surfaces sont appelées superhydrophobes : les rugosités retiennent une couche d'air sous la goutte qui repose donc sur coussin d'air. En situation(...)
    Matériaux multifonctions : antipluie, antibuée, antireflets
    Sur une surface couverte de microrugosités hydrophobes, l'eau est ultra-mobile. Ces surfaces sont appelées superhydrophobes : les rugosités retiennent une couche d'air sous la goutte qui repose donc sur coussin d'air. En situations humides, la buée dans les textures peut altérer ces propriétés anti-eau. Comme le (...)

  • Séminaire PMMH : Pascal Raux
    

    Interactions entre grains et liquides

    Dans cette présentation, je propose d'illustrer la diversité des interactions entre grains et liquide au travers de différents problèmes :
    – L'ajout de liquide accroit la cohésion du milieu granulaire. (...)
    Interactions entre grains et liquides
    Dans cette présentation, je propose d'illustrer la diversité des interactions entre grains et liquide au travers de différents problèmes : – L'ajout de liquide accroit la cohésion du milieu granulaire. Contrairement aux régimes où le liquide est en faible quantité, la transition vers un milieu granulaire saturé a reçu (...)

  • Séminaire PMMH - Philip Marcus (University of California, Berkeley)
    

    Optimal Design by Morphing : Is the Navier-Stokes Equation the Best Method for Describing Fluid Dynamics ?

    We present a new method, which we call design-by-morphing, for the optimal hydrodynamic or aerodynamic design of the shape of an object. Traditional morphing methods, which require coverin(...)
    Optimal Design by Morphing : Is the Navier-Stokes Equation the Best Method for Describing Fluid Dynamics ?
    We present a new method, which we call design-by-morphing, for the optimal hydrodynamic or aerodynamic design of the shape of an object. Traditional morphing methods, which require covering the surface of an object with a large number (typically millions) of triangular meshed points, cannot be used in searches for (...)

  • Séminaire PMMH : Marcelo Dias (James Madison University)
    

    Thin Elastic Structures : A roadmap from forms to functions

    Thin elastic structures (e.g. plates and shells) have stimulated new approaches and applications to mechanical metamaterials as well as brought to light many fundamental questions in our understanding of shape and function. Insights of(...)
    Thin Elastic Structures : A roadmap from forms to functions
    Thin elastic structures (e.g. plates and shells) have stimulated new approaches and applications to mechanical metamaterials as well as brought to light many fundamental questions in our understanding of shape and function. Insights of what functionality roles these structures play comes from connections between (...)

  • Séminaire PMMH - Patrick Guenoun (CEA)
    

    Elasticity of nano structured objects probed by AFM

    In this communication we will describe how Atomic Force Microscopy (AFM) was used to investigate the mechanical properties of nanostructured objects. These objects are nanocapsules designed for a theranostic approach where they can provide bot(...)
    Elasticity of nano structured objects probed by AFM
    In this communication we will describe how Atomic Force Microscopy (AFM) was used to investigate the mechanical properties of nanostructured objects. These objects are nanocapsules designed for a theranostic approach where they can provide both acoustic imaging properties in vivo and release properties of (...)

  • Séminaire PMMH - Camille Duprat (LadHyX)
    

    Catching drops with fibers

    In this talk, I will present recent results on the capture of aerosol droplets with a textile, i.e. a fibrous material. Fibrous media are commonly used to collect droplets from an aerosol ; woven nets are used to harvest fresh water from fog, and non-woven entangled (...)
    Catching drops with fibers
    In this talk, I will present recent results on the capture of aerosol droplets with a textile, i.e. a fibrous material. Fibrous media are commonly used to collect droplets from an aerosol ; woven nets are used to harvest fresh water from fog, and non-woven entangled fibers are used to filter oil drops from gas (...)

  • Séminaire PMMH - Eric Dufresne (ETH, Zurich)
    

    Three-Phase Contacts with Soft Solid Substrates

    Surface forces can drive large deformations of soft solids. I will discuss the deformation of soft solids in contact with liquid droplets and rigid particles. Here, classic results for wetting and adhesion fail to describe the equilibrium of thre(...)
    Three-Phase Contacts with Soft Solid Substrates
    Surface forces can drive large deformations of soft solids. I will discuss the deformation of soft solids in contact with liquid droplets and rigid particles. Here, classic results for wetting and adhesion fail to describe the equilibrium of three-phase contact lines. While interfacial energies are sufficient to (...)

  • Séminaire PMMH - Antonio de Simone (SISSA, Trieste, Italy)
    

    On shape control : some case studies inspired by biological and bio-inspired locomotion at small scales

    Control of shape is at the root of many processes of fundamental relevance in Biology, from morphogenesis to locomotion.

    For slender one-dimensional objects (rods) or thin two-dimensio(...)
    On shape control : some case studies inspired by biological and bio-inspired locomotion at small scales
    Control of shape is at the root of many processes of fundamental relevance in Biology, from morphogenesis to locomotion. For slender one-dimensional objects (rods) or thin two-dimensional ones (plates and shells), shape can be controlled by adjusting curvature thanks to the application of active internal (...)

  • Séminaire PMMH - Henri Van Damme (ESPCI-MIT)
    

    Gaz et huile de « schiste » : un bon sujet, quoiqu'il advienne ?

    Les réservoirs pétroliers auto-sourcés sont des roches compactes riches en matière organique qui sont exploités comme source de gaz naturel et/ou de pétrole dits « non conventionnels ». Ils tirent leur qualificatif « au(...)
    Gaz et huile de « schiste » : un bon sujet, quoiqu'il advienne ?
    Les réservoirs pétroliers auto-sourcés sont des roches compactes riches en matière organique qui sont exploités comme source de gaz naturel et/ou de pétrole dits « non conventionnels ». Ils tirent leur qualificatif « auto-sourcés » du fait que les hydrocarbures qu'ils contiennent ont été générés sur place et ont échappé à la (...)

  • Séminaire PMMH - Corrado Rainone (Weizmann Institute, Israel)
    

    Shear bands as manifestation of a criticality in yielding amorphous solids.

    The nature of the yielding transition in amorphous solids is a long-standing riddle which has attracted a lot of research effort in recent years. Recently, some of us have proposed a picture of yielding as a first-order(...)
    Shear bands as manifestation of a criticality in yielding amorphous solids.
    The nature of the yielding transition in amorphous solids is a long-standing riddle which has attracted a lot of research effort in recent years. Recently, some of us have proposed a picture of yielding as a first-order like transition in a suitable overlap order parameter, measuring the degree of similarity (...)

  • Séminaire PMMH - Alexandre Danescu (EC, Lyon)
    

    Design of three-dimensional objects using stress relaxation in thin films : the interplay between mechanics and geometry

    It is well-known that a free pre-stressed elastic bi-layer will deform so as to "relax" its total energy. The relaxation process may deform simple straight segments to rolls,(...)
    Design of three-dimensional objects using stress relaxation in thin films : the interplay between mechanics and geometry
    It is well-known that a free pre-stressed elastic bi-layer will deform so as to "relax" its total energy. The relaxation process may deform simple straight segments to rolls, or curls, etc. In an attempt to cover more complex three-dimensional geometries we address and solve the general question concerning the (...)

  • Séminaire PMMH - AIMEE K. WESSEL (INSTITUT PASTEUR)
    

    Examining prokaryotic community behavior using 3D printing

    Bacterial communities engage in social activities, exhibiting behaviors such as communicating with small signaling molecules (quorum sensing [QS]) and building antibiotic-resistant biofilms. Most of our understanding of QS and biofilm f(...)
    Examining prokaryotic community behavior using 3D printing
    Bacterial communities engage in social activities, exhibiting behaviors such as communicating with small signaling molecules (quorum sensing [QS]) and building antibiotic-resistant biofilms. Most of our understanding of QS and biofilm formation arises from in vitro studies of bacterial communities containing large (...)

  • Séminaire PMMH - John Brady (CalTech)
    

    Forces, Stresses and the (Thermo ?)dynamics of Active Matter

    A distinguishing feature of many living systems is their ability to move - to be active. Through their motion living systems are able to self-assemble : birds flock, fish school, bacteria swarm, etc. But such behavior is not limited t(...)
    Forces, Stresses and the (Thermo ?)dynamics of Active Matter
    A distinguishing feature of many living systems is their ability to move - to be active. Through their motion living systems are able to self-assemble : birds flock, fish school, bacteria swarm, etc. But such behavior is not limited to living systems. Recent advances in colloid chemistry have led to the (...)

  • Séminaire PMMH - Pierre-Yves Passaggia (Univ. of North Carolina)
    

    Convection horizontale : stabilité, bifurcation et son rôle dans la circulation méridionale des océans.

    Le rôle des différents phénomènes physiques responsables de la circulation méridionale des océans reste une question ouverte. Afin de comprendre l'impact du différentiel de tempér(...)
    Convection horizontale : stabilité, bifurcation et son rôle dans la circulation méridionale des océans.
    Le rôle des différents phénomènes physiques responsables de la circulation méridionale des océans reste une question ouverte. Afin de comprendre l'impact du différentiel de température entre les pôles et l'équateur à la surface des océans sur cette circulation, un modèle d'écoulement dans une cavité, chauffée et refroidie à (...)

  • Séminaire PMMH - Stéphane Popinet (Institut d'Alembert)
    

    Adaptive numerical methods for fluid mechanics

    The equations of fluid mechanics can be used to describe natural
    processes over a wide range of scales, from the behaviour of
    micro-organisms to astrophysics. Each of these processes is in
    Adaptive numerical methods for fluid mechanics
    The equations of fluid mechanics can be used to describe natural processes over a wide range of scales, from the behaviour of micro-organisms to astrophysics. Each of these processes is in turn often controlled by internal interactions on widely different scales. Numerical methods able to efficiently resolve these (...)

  • Séminaire PMMH - Maximilien Levesque (ENS, Paris)
    

    The one molecule in a sea of others : tackling solvation at the molecular scale

    by Maximilien Levesque, laboratoire PASTEUR, Ecole Normale Supérieure

    Physical and chemical processes in the liquid and gas phases happen in an embedding medium, a large number of solvent molecules, for inst(...)
    The one molecule in a sea of others : tackling solvation at the molecular scale
    by Maximilien Levesque, laboratoire PASTEUR, Ecole Normale Supérieure Physical and chemical processes in the liquid and gas phases happen in an embedding medium, a large number of solvent molecules, for instance water, that crowd the environment. To take into account this environment at the molecular scale, (...)

  • Séminaire PMMH - Hamid Kellay (LOMA, Université de Bordeaux)
    

    Hydrodynamics experiments using soap films and soap bubbles

    I will describe experiments using soap films and soap bubbles to illustrate the interest of these common objects to some fluid mechanics problems. The flow in the very thin layer of these films is basically two dimensional and this pr(...)
    Hydrodynamics experiments using soap films and soap bubbles
    I will describe experiments using soap films and soap bubbles to illustrate the interest of these common objects to some fluid mechanics problems. The flow in the very thin layer of these films is basically two dimensional and this property brings fundamental differences with fluid flows in three dimensions as (...)

  • Séminaire PMMH - Etienne Barthel (SIMM, ESPCI)
    

    Telephone Cords, parrot ladders, hexagons and the like - the unexpected morphologies of thin film buckles

    Thin films with large compressive residual stresses and low adhesion are prone to buckling and delamination. This is both a significant technical issue, with relevance to thin film stabilit(...)
    Telephone Cords, parrot ladders, hexagons and the like - the unexpected morphologies of thin film buckles
    Thin films with large compressive residual stresses and low adhesion are prone to buckling and delamination. This is both a significant technical issue, with relevance to thin film stability, and an interesting academic problem where (non-linear) plate mechanics couples to mixed mode adhesion. This coupling (...)

  • Séminaire PMMH - Chinar Rana (ULB, Bruxelles)
    

    Effects of adsorption and viscous fingering instability on the dispersion and the form of the peaks in liquid chromatography

    Liquid chromatography is a flow based separation method where, a given fluid (called eluent) displaces a miscible sample consisting of a solvent in which a mixture of sol(...)
    Effects of adsorption and viscous fingering instability on the dispersion and the form of the peaks in liquid chromatography
    Liquid chromatography is a flow based separation method where, a given fluid (called eluent) displaces a miscible sample consisting of a solvent in which a mixture of solutes (also named analytes) is dissolved. The analytes are separated during the displacement because of the selective adsorption on the porous (...)

  • Séminaire PMMH - Tamas Borzsonyi (Wigner Research Center for Physics, Budapest)
    

    Rotation and ordering of elongated particles under shear

    Ordering and alignment of elongated objects in shear flows can be observed
    at all length scales, in log jams on rivers, in seeds, nanorods, viruses,
    and even at molecular scales in nematic liquid (...)
    Rotation and ordering of elongated particles under shear
    Ordering and alignment of elongated objects in shear flows can be observed at all length scales, in log jams on rivers, in seeds, nanorods, viruses, and even at molecular scales in nematic liquid crystals. We show, that for dry granular materials in steady shear flow the time and ensemble averaged direction of the (...)

  • Séminaire PMMH - Brigitte Senut (Muséum National d'Histoire Naturelle)
    

    Des grands singes et des hommes : une histoire dans les arbres

    À la lueur des découvertes récentes africaines, nous pouvons mieux appréhender nos origines ; mais ces dernières sont-elles vraiment africaines ? Sous quelles conditions climatiques l'émergence des grands singes modernes et de(...)
    Des grands singes et des hommes : une histoire dans les arbres
    À la lueur des découvertes récentes africaines, nous pouvons mieux appréhender nos origines ; mais ces dernières sont-elles vraiment africaines ? Sous quelles conditions climatiques l'émergence des grands singes modernes et des premiers hominidés peut-elle être envisagée ? Si on a souvent considéré la savane sèche comme un (...)

  • Séminaire PMMH : Sébastien Candel (EM2C, Centrale Paris / Académie des sciences)
    

    La complexité de la combustion et comment la gérer

    La combustion est une des sources de la civilisation. Son rôle actuel est considérable puisqu'elle fournit aujourd'hui 85% de l'énergie primaire consommée dans le monde. L'homme maîtrise le feu depuis un demi-million d'années mais la sc(...)
    La complexité de la combustion et comment la gérer
    La combustion est une des sources de la civilisation. Son rôle actuel est considérable puisqu'elle fournit aujourd'hui 85% de l'énergie primaire consommée dans le monde. L'homme maîtrise le feu depuis un demi-million d'années mais la science de la combustion est bien plus récente. On propose dans ce séminaire un panorama (...)

  • Séminaire PMMH - Anaël Lemaître (Laboratoire Navier, ENPC)
    

    Structural relaxation is a scale-free process

    Structural relaxation is the process via which a liquid explores its
    equilibrium ensemble. It is responsible for the dramatic slowing down at
    the glass transition, and has thus received a quite considerabl(...)
    Structural relaxation is a scale-free process
    Structural relaxation is the process via which a liquid explores its equilibrium ensemble. It is responsible for the dramatic slowing down at the glass transition, and has thus received a quite considerable amount of attention. Yet, the mechanisms governing relaxation are still largely unknown. We will (...)

  • Séminaire PMMH - Laurent Chevillard (ENS-Lyon)
    

    Une peinture aléatoire de la turbulence des fluides

    Dans une première partie de cet exposé, je rappellerai quelques propriétés universelles de la turbulence des fluides observées dans les expériences et simulations numériques des écoulements homogènes et isotropes. J'insisterai sur la(...)
    Une peinture aléatoire de la turbulence des fluides
    Dans une première partie de cet exposé, je rappellerai quelques propriétés universelles de la turbulence des fluides observées dans les expériences et simulations numériques des écoulements homogènes et isotropes. J'insisterai sur la statistique des fluctuations de la vitesse, aussi bien dans un cadre spatial (description (...)

  • Séminaire PMMH - Catherine Quiminal, Paul Schor (Université Paris Diderot)
    

    Politiques migratoires et parcours de migrants

    – Il s'agit dans ce bref exposé de mettre en regard les politiques migratoires, les politiques réglementant la circulation des gens, les catégories qu'elles produisent, véhiculent sur lesquelles elles(...)
    Politiques migratoires et parcours de migrants
    – Il s'agit dans ce bref exposé de mettre en regard les politiques migratoires, les politiques réglementant la circulation des gens, les catégories qu'elles produisent, véhiculent sur lesquelles elles s'appuient avec le parcours de migrants à travers des figures types ou réelles, stylisées de migrants d'Afrique (...)

  • Séminaire PMMH - Lydéric Bocquet (LPS, ENS)
    

    Osmotic flows, from nanoscales to kidney filtration

    Osmosis describes the flow of water across semipermeable membranes powered by the chemical free energy contained in salinity gradients. It is a fundamental transport
    process for water in all living systems, and its applica(...)
    Osmotic flows, from nanoscales to kidney filtration
    Osmosis describes the flow of water across semipermeable membranes powered by the chemical free energy contained in salinity gradients. It is a fundamental transport process for water in all living systems, and its applications are countless. While osmosis can be expressed fundamentally in simple terms via the (...)

  • Séminaire du PMMH : Constantino Tsallis (CBPF, Brésil)
    

    On the foundations of statistical mechanics : Concepts and applications

    Whenever basic hypothesis such as ergodicity are not satisfied, the Boltzmann-Gibbs statistical mechanics, based on the additive Boltzmann-Gibbs entropy, can yield results that are not confirmed by experiments. A more gener(...)
    On the foundations of statistical mechanics : Concepts and applications
    Whenever basic hypothesis such as ergodicity are not satisfied, the Boltzmann-Gibbs statistical mechanics, based on the additive Boltzmann-Gibbs entropy, can yield results that are not confirmed by experiments. A more general theory, namely nonextensive statistical mechanics, based on nonadditive entropies, (...)

  • Séminaire PMMH - Marino Arroyo (UPC)
    

    Reverse engineering the motility of euglena cells : shape transformations and the interaction with the environment

    Euglenids are unicellular aquatic organisms capable of moving either by beating a flagellum or by executing dramatic and harmonious shape changes, whose function still remains uncl(...)
    Reverse engineering the motility of euglena cells : shape transformations and the interaction with the environment
    Euglenids are unicellular aquatic organisms capable of moving either by beating a flagellum or by executing dramatic and harmonious shape changes, whose function still remains unclear. These shape changes are accomplished thanks to a complex structure underlying the plasma membrane, made of interlocking (...)

  • Séminaire PMMH - Arnold Mathijssen & Andreas Zöttl (University of Oxford)
    

    Hydrodynamics and noise in confined microswimmer suspensions

    Active particles and biological microswimmers such as bacteria or sperm cells moving in their natural environment are continually subjected to fluid flow and confining surfaces. To understand the underlying basic physical mechanisms i(...)
    Hydrodynamics and noise in confined microswimmer suspensions
    Active particles and biological microswimmers such as bacteria or sperm cells moving in their natural environment are continually subjected to fluid flow and confining surfaces. To understand the underlying basic physical mechanisms in these environments their locomotion in microfluidic channels is nowadays widely (...)

  • Séminaire PMMH - Mónica S. N. Oliveira (Univ. of Strathclyde)
    

    Extension dominated flows at the microscale : from instabilities to optimisation

    James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ, United Kingdom

    The use of microfluidic devices has found applications in a range o(...)
    Extension dominated flows at the microscale : from instabilities to optimisation
    James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ, United Kingdom The use of microfluidic devices has found applications in a range of different areas, many of which make use of complex fluids, such as biofluids and polymer solutions that (...)

  • Séminaire PMMH - Ryan Hayward (U. Mass. Amherst)
    

    Folding gels and shells : Origami-based design of reconfigurable 3D structures and ‘mechanical meta-materials'

    Centuries of artistic tradition, coupled with recent advances in the mathematics and mechanics of folded structures, have made origami a powerful method for the design of materials (...)
    Folding gels and shells : Origami-based design of reconfigurable 3D structures and ‘mechanical meta-materials'
    Centuries of artistic tradition, coupled with recent advances in the mathematics and mechanics of folded structures, have made origami a powerful method for the design of materials with reconfigurable shapes and tailored mechanical properties. Inspired by these possibilities, our group has studied the design and (...)

  • Séminaire PMMH - Philippe Marmottant (LIPhy, Grenoble)
    

    Cavitation of sap in trees and leaves

    In this talk, we will present our investigations on the nucleation of bubbles in tree vessels, by showing experiments on wood and on leaves. Such explosive bubbles occur by cavitation, since the liquid sap in trees is under extreme negative pressure. They f(...)
    Cavitation of sap in trees and leaves
    In this talk, we will present our investigations on the nucleation of bubbles in tree vessels, by showing experiments on wood and on leaves. Such explosive bubbles occur by cavitation, since the liquid sap in trees is under extreme negative pressure. They form an emboly that can develop and affect the hydraulic (...)

  • Séminaire PMMH - Roland Winkler (Forschungszentrum Jülich)
    

    Microswimmer : From swimming bacteria to collective behaviors of active Brownian particles

    Locomotion is a major achievement of biological evolution. Microorganisms, such as bacteria, algae, and sperm cells are equipped with flagella and are able to exploit drag for their propulsion. Two promin(...)
    Microswimmer : From swimming bacteria to collective behaviors of active Brownian particles
    Locomotion is a major achievement of biological evolution. Microorganisms, such as bacteria, algae, and sperm cells are equipped with flagella and are able to exploit drag for their propulsion. Two prominent swimming mechanisms are rotating helical flagella, exploited by many bacteria, and snake-like or whip-like (...)

  • Séminaire PMMH - Carine Douarche (LPS, Univ. Paris-Sud)
    

    Bacteria self-assemblies lead to hydrodynamic instabilities

    The mechanisms of the bacterial motility and chemotaxis are now quite well known at the single cell level ; however the way a whole cell population moves at a macroscopic scale still raises some fundamental questions. The study of the (...)
    Bacteria self-assemblies lead to hydrodynamic instabilities
    The mechanisms of the bacterial motility and chemotaxis are now quite well known at the single cell level ; however the way a whole cell population moves at a macroscopic scale still raises some fundamental questions. The study of the behavior of a population of Escherichia coli in oxygen gradients in the bulk of (...)

  • Séminaire PMMH - Alberto Fernandez-Nieves (Georgia Tech)
    

    Active nematics on tori

    We will discuss recent results with active nematics on toroidal surfaces. We will start by briefly discussing how we make toroidal droplets, how these evolve in time, and how we stabilize the toroidal shape. We will then address how nematic liquid crystals organize on th(...)
    Active nematics on tori
    We will discuss recent results with active nematics on toroidal surfaces. We will start by briefly discussing how we make toroidal droplets, how these evolve in time, and how we stabilize the toroidal shape. We will then address how nematic liquid crystals organize on the surface of stable tori. Despite no defects (...)

  • Séminaire PMMH - Scott Waitukaitis (Univ. Leiden)
    

    Rabbits, Planets, Volcanoes, Dust Devils : The Surprising Physics of Granular Tribocharging

    If you shuffle your feet across a carpet and touch a doorknob, you might get shocked. This is tribocharging—the transfer of electrical charge between different materials. Although it was observed as ea(...)
    Rabbits, Planets, Volcanoes, Dust Devils : The Surprising Physics of Granular Tribocharging
    If you shuffle your feet across a carpet and touch a doorknob, you might get shocked. This is tribocharging—the transfer of electrical charge between different materials. Although it was observed as early as 600 B.C. in ancient Greece, we know surprisingly little about it. One of the most perplexing observations (...)

  • Séminaire PMMH - Joseph Paulsen (Syracuse University)
    

    The wavelength of wrinkles in elastic sheets on curved topographies

    A thin elastic sheet will buckle when it is compressed, leading to the familiar wrinkle patterns on our foreheads, on plastic-wrapped objects, and on crinkly leaves. Wrinkling has recently been used as a noninvasive probe of th(...)
    The wavelength of wrinkles in elastic sheets on curved topographies
    A thin elastic sheet will buckle when it is compressed, leading to the familiar wrinkle patterns on our foreheads, on plastic-wrapped objects, and on crinkly leaves. Wrinkling has recently been used as a noninvasive probe of thin film properties and mechanical environment. However, the current understanding of (...)

  • Séminaire PMMH - Pawel Pieranski (LPS, Orsay)
    

    Cunéitropisme et les défauts de la texture furcelle

    Après une introduction large aux cristaux liquides, nous montrerons comment générer de façon reproductible la texture pseudo-planaire [1] (voir fig. a) et nous verrons que dans certaines conditions sa durée de vie peut être pratiquemen(...)
    Cunéitropisme et les défauts de la texture furcelle
    Après une introduction large aux cristaux liquides, nous montrerons comment générer de façon reproductible la texture pseudo-planaire [1] (voir fig. a) et nous verrons que dans certaines conditions sa durée de vie peut être pratiquement infinie. La propriété la plus saillante de cette version immortelle de la texture (...)

  • Séminaire PMMH - Frédéric Restagno (LPS, Univ. Paris-Sud)
    

    FRICTION AT MICRO AND MACRO-SCALE

    Friction is a common phenomenon that occurs when to objects are force to move tangentially relatively to each other. During this seminar, we shall present two series of experiments concerning friction at macro and micro-scale.

    In a first set of experimen(...)
    FRICTION AT MICRO AND MACRO-SCALE
    Friction is a common phenomenon that occurs when to objects are force to move tangentially relatively to each other. During this seminar, we shall present two series of experiments concerning friction at macro and micro-scale. In a first set of experiment [1], we will study the aptitude of surface with anchored (...)

  • Clément Sire (LPT, Université Paul Sabatier, Toulouse)
    

    Phase diagram of a data-driven fish school model

    After some generalities concerning "intelligent" active matter ("social" vs physical "forces", effect of anisotropic sensorial stimuli, additivity of "forces"...), and in particular fish schools, I will present a series of experiments performed i(...)
    Phase diagram of a data-driven fish school model
    After some generalities concerning "intelligent" active matter ("social" vs physical "forces", effect of anisotropic sensorial stimuli, additivity of "forces"...), and in particular fish schools, I will present a series of experiments performed in Guy Theraulaz' group at the CRCA in Toulouse, and a class of models (...)

  • Séminaire PMMH - Adama Creppy (FAST)
    

    Etude de la dynamique collective de spermatozoïdes

    Les micro-organismes présentent des comportements collectifs qui émergent des interactions qui se produisent à l'échelle individuelle. Dans le cas des suspensions concentrées (fraction volumique > 50 %) les effets stériques deviennent do(...)
    Etude de la dynamique collective de spermatozoïdes
    Les micro-organismes présentent des comportements collectifs qui émergent des interactions qui se produisent à l'échelle individuelle. Dans le cas des suspensions concentrées (fraction volumique > 50 %) les effets stériques deviennent dominants. C'est le cas du liquide séminal de bélier sur lequel cette étude a (...)

  • Séminaire PMMH - Julien Derr (MSC)
    

    Morphogenesis and Motions in Biological Systems

    The constraints of the environment always plays a determinant role in the development of biological systems and dynamical aspects are also important. That's why we have been investigating the link between morphogenesis in biological systems and th(...)
    Morphogenesis and Motions in Biological Systems
    The constraints of the environment always plays a determinant role in the development of biological systems and dynamical aspects are also important. That's why we have been investigating the link between morphogenesis in biological systems and their associated motions. We distinguish two types of motions. First, (...)

  • Séminaire PMMH - Antoine Naert (ENS Lyon)
    

    Expériences de physique statistique dans les gaz granulaires

    Un gaz granulaire peut être considéré comme le paradigme d'un thermostat dissipatif. En d'autres termes, lui donner ou lui prendre une petite quantité d'énergie ne change pas son état macroscopique stationnaire. Bien sûr, il e(...)
    Expériences de physique statistique dans les gaz granulaires
    Un gaz granulaire peut être considéré comme le paradigme d'un thermostat dissipatif. En d'autres termes, lui donner ou lui prendre une petite quantité d'énergie ne change pas son état macroscopique stationnaire. Bien sûr, il est nécessaire de donner au gaz granulaire une puissance mécanique pour compenser la dissipation (...)

  • Fabian Brau (Université Libre de Bruxelles)
    

    Patterns dans les plaques minces élastiques

    De nombreux types de motifs émergeant spontanément peuvent être observés dans des systèmes impliquant des plaques mince élastiques et soumis à des contraintes externes ou internes (compression ou croissance différentielle, cisaillement, déch(...)
    Patterns dans les plaques minces élastiques
    De nombreux types de motifs émergeant spontanément peuvent être observés dans des systèmes impliquant des plaques mince élastiques et soumis à des contraintes externes ou internes (compression ou croissance différentielle, cisaillement, déchirure, etc.). Ces systèmes mécaniques peuvent parfois être vus comme des (...)

  • Séminaire PMMH - Christophe Eloy (IRPHE, Marseille)
    

    Auto-similarité et architecture des arbres

    La partie aérienne d'un arbre peut être vue comme la réponse biologique au problème d'ingénierie suivant : réaliser une structure mécaniquement stable, la plus légère possible et permettant un accès maximal à la lumière. Pour répondre à (...)
    Auto-similarité et architecture des arbres
    La partie aérienne d'un arbre peut être vue comme la réponse biologique au problème d'ingénierie suivant : réaliser une structure mécaniquement stable, la plus légère possible et permettant un accès maximal à la lumière. Pour répondre à ce cahier des charges, l'arbre croît, en produisant à chaque étape de sa croissance des (...)

  • Teo Burghelea (CNRS, Laboratoire de Thermocinétique de Nantes)
    

    Rheological properties and microscopic flows of suspensions of the non-motile green micro-alga Chlorella Vulgaris

    In the first part of the talk I will present a systematic study of the rheological properties of solutions of non-motile micro-algae (Chlorella vulgaris CCAP 211-19) in a wi(...)
    Rheological properties and microscopic flows of suspensions of the non-motile green micro-alga Chlorella Vulgaris
    In the first part of the talk I will present a systematic study of the rheological properties of solutions of non-motile micro-algae (Chlorella vulgaris CCAP 211-19) in a wide range of volume fractions is presented. As the volume fraction is gradually increased, several rheological regimes are observed. At low (...)

  • Megan T. Valentine (UCSB)
    

    Learning from nature : how mussels stick to rocks, and what it can teach us about material design

    Mussels permanently adhere to surfaces through a circular plaque that is
    attached to the animal body via a long thin thread ; forming a
    mushroom-shaped geo(...)
    Learning from nature : how mussels stick to rocks, and what it can teach us about material design
    Mussels permanently adhere to surfaces through a circular plaque that is attached to the animal body via a long thin thread ; forming a mushroom-shaped geometry. A plaque just a few millimeters in diameter with a 250-micron diameter thread can withstand large pull forces of a several Newtons without debonding. (...)

  • Michaël Benzaquen (PCT, Gulliver, ESPCI)
    

    Waves and wakes at different scales

    Simply by looking at a duck swimming in a pond or a cargo ship moving on a calm sea, one can clearly tell that there is something common about their wake. Indeed, they both display a familiar V-shaped pattern which only differ from one another by their dimens(...)
    Waves and wakes at different scales
    Simply by looking at a duck swimming in a pond or a cargo ship moving on a calm sea, one can clearly tell that there is something common about their wake. Indeed, they both display a familiar V-shaped pattern which only differ from one another by their dimensions. In 1887, Lord Kelvin was able to provide a theory (...)

  • Alexandre Darmon (EC2M, Gulliver, ESPCI)
    

    Waltzing defects in cholesteric liquid crystal shells : interplay between topology and elasticity

    Confining rod-like molecules, such as nematogens of liquid crystals, on a curved surface inevitably yields topological defects, which are singular points where the alignment between molecules can n(...)
    Waltzing defects in cholesteric liquid crystal shells : interplay between topology and elasticity
    Confining rod-like molecules, such as nematogens of liquid crystals, on a curved surface inevitably yields topological defects, which are singular points where the alignment between molecules can no longer be fulfilled. Remarkably, in the specific case of a nematic sphere, Poincaré stated that the sum of the (...)

  • Agnese Seminara (LPMC, Université de Nice)
    

    Olfactory navigation in mice

    The ability to shift between multiple decision-making strategies during natural behavior allows animals to strike a balance between flexibility and efficiency. We investigated odor-guided navigation by mice to understand how decision making strategies are balanced d(...)
    Olfactory navigation in mice
    The ability to shift between multiple decision-making strategies during natural behavior allows animals to strike a balance between flexibility and efficiency. We investigated odor-guided navigation by mice to understand how decision making strategies are balanced during a complex natural behavior. Mice navigated (...)

  • Pascal Hémon (LadHyX, École Polytechnique)
    

    La simulation du vent sur les constructions : l'exemple de la Fondation Louis Vuitton

    Au-delà des effets statiques, le calcul des effets des rafales de vent sur les constructions représente parfois un défi scientifique et technique. La Fondation Louis Vuitton récemment inaugurée près de P(...)
    La simulation du vent sur les constructions : l'exemple de la Fondation Louis Vuitton
    Au-delà des effets statiques, le calcul des effets des rafales de vent sur les constructions représente parfois un défi scientifique et technique. La Fondation Louis Vuitton récemment inaugurée près de Paris en est un parfait exemple. Les douze voiles de verre qui entourent le bâtiment imaginé par l'architecte Frank (...)

  • Sylvain Courrech du Pont (MSC)
    

    Formes et dynamique des dunes

    La physique des dunes repose sur l'interaction entre le vent et une topographie érodable. Quand le vent souffle au-dessus d'une surface de sable, des dunes se forment dès lors que des grains sont transportés. Dans les déserts de sable, les vents soufflent gén�(...)
    Formes et dynamique des dunes
    La physique des dunes repose sur l'interaction entre le vent et une topographie érodable. Quand le vent souffle au-dessus d'une surface de sable, des dunes se forment dès lors que des grains sont transportés. Dans les déserts de sable, les vents soufflent généralement dans des directions et avec des forces différentes (...)

  • Michael Le Bars (IRPHE, Marseille)
    

    Forme, durée de vie et instabilités d'un tourbillon dans un fluide stratifié tournant

    Les océans, les atmosphères planétaires, les disques d'accrétion, constituent autant de milieux naturels fluides stratifiés et tournants. Au sein de ces environnements complexes, des structures tourbil(...)
    Forme, durée de vie et instabilités d'un tourbillon dans un fluide stratifié tournant
    Les océans, les atmosphères planétaires, les disques d'accrétion, constituent autant de milieux naturels fluides stratifiés et tournants. Au sein de ces environnements complexes, des structures tourbillonnaires à grande échelle peuvent se développer, présentant une exceptionnelle longévité, comme par exemple La Grande (...)

  • Pierre Coullet (Université de Nice Sophia Antipolis)
    

    21 siècles de géométrie physique

    De la duplication du cube à la théorie universelle de la gravitation avec entre autres …Archimède, Apollonius, Alazen et Newton

    21 siècles de géométrie physique
    De la duplication du cube à la théorie universelle de la gravitation avec entre autres …Archimède, Apollonius, Alazen et Newton
  • Bartosz Protas (McMaster University, Canada)
    

    Les tourbillons extrêmes et le problème des singularités en mécanique des fluides

    Dans cet exposé on va présenter quelques directions nouvelles de recherche et les résultats récents concernant l'étude du comportement extrême en hydrodynamique. Ces problèmes sont motivés par les esti(...)
    Les tourbillons extrêmes et le problème des singularités en mécanique des fluides
    Dans cet exposé on va présenter quelques directions nouvelles de recherche et les résultats récents concernant l'étude du comportement extrême en hydrodynamique. Ces problèmes sont motivés par les estimations fondamentales de la croissance maximale de l'enstrophie dans les écoulements en 3D, qui sont intimement liées à la (...)

  • Jonathan Rothstein (UMass Amherst)
    

    Viscoelastic Fluid Structure Interactions

    How Elastic Flow Instabilities can Induce Motion in Flexible Solid Structures

    When a flexible object such as an elastic sheet is placed in a flow of a Newtonian fluid, the shedding of separated vortices at high Reynolds number ca(...)
    Viscoelastic Fluid Structure Interactions
    How Elastic Flow Instabilities can Induce Motion in Flexible Solid Structures When a flexible object such as an elastic sheet is placed in a flow of a Newtonian fluid, the shedding of separated vortices at high Reynolds number can drive the motion of the structure. This phenomenon is known as Vortex-Induced (...)

  • Stéphane Roux (LMT, ENS Cachan)
    

    Faut-il 7 équations pour déterminer 7 inconnues ? ou 9 ? ou 5 ?

    L'imagerie et les mesures de champs offrent une considérable richesse d'information mais sont aussi affectées par un fort niveau de bruit. Cela pose donc le problème de la mesure de manière particulièrement aigüe. La redond(...)
    Faut-il 7 équations pour déterminer 7 inconnues ? ou 9 ? ou 5 ?
    L'imagerie et les mesures de champs offrent une considérable richesse d'information mais sont aussi affectées par un fort niveau de bruit. Cela pose donc le problème de la mesure de manière particulièrement aigüe. La redondance (« 9 équations pour 7 inconnues ») est utile mais nécessite de bien connaitre le bruit pour en (...)

  • Soft Matter Days 2015
    

    Gathering ESPCI persons working in the field of soft matter in order to share their research activity in a relaxing atmosphere

    Version française On Jul(...) 20150424ad. David González-Rodríguez (LadHyX, Ecole Polytechnique) Biofluid Mechanics at the Subcellular Scale In this talk I will present two problems in cell mechanics where insight is gained through analogies with surface-tension-driven flow. First I will discuss how endothelial cells can oppose the opening of transcellular tunnels that are induced b(...) Biofluid Mechanics at the Subcellular Scale In this talk I will present two problems in cell mechanics where insight is gained through analogies with surface-tension-driven flow. First I will discuss how endothelial cells can oppose the opening of transcellular tunnels that are induced by certain bacterial infections. The experimentally observed dynamics (...) 20150417ac. Kenny Breuer (Brown University) Aeromechanics of Bat Flight : From Live Animals to Robotic Models The elegance and maneuverability of bats during flight is unparalleled in both the natural and the man-made world, and they serve as a source of inspiration for scientists trying to understand the evolution of flight and for engi(...) Aeromechanics of Bat Flight : From Live Animals to Robotic Models The elegance and maneuverability of bats during flight is unparalleled in both the natural and the man-made world, and they serve as a source of inspiration for scientists trying to understand the evolution of flight and for engineers designing highly agile flight vehicles. We have been exploring this rich (...) 20150410ac. Jacques Treiner (UPMC et Sciences-Po, Paris) Changement climatique : pourquoi l'objectif des 2°C appartient, hélas, au passé Depuis la réunion internationale de Copenhague en décembre 2009 (COP15), un certain nombre de pays se sont engagés sur l'objectif de ne pas dépasser un réchauffement moyen de la surface de la Terre de 2°C. (...) Changement climatique : pourquoi l'objectif des 2°C appartient, hélas, au passé Depuis la réunion internationale de Copenhague en décembre 2009 (COP15), un certain nombre de pays se sont engagés sur l'objectif de ne pas dépasser un réchauffement moyen de la surface de la Terre de 2°C. Cette valeur, choisie à la suite de négociations extrêmement difficiles entre 26 pays seulement (notamment sans l'UE) (...) 20150403ab. Dmitry Kolomensky (McGill University) Numerical modelling of insect flight Numerical simulation can provide important insights to the mechanics of animal locomotion. In this talk, I will present a numerical method for modeling flapping flight of insects. It is based on a Fourier pseudo-spectral method for solving the Navier-Stokes (...) Numerical modelling of insect flight Numerical simulation can provide important insights to the mechanics of animal locomotion. In this talk, I will present a numerical method for modeling flapping flight of insects. It is based on a Fourier pseudo-spectral method for solving the Navier-Stokes equations. Time-varying solid boundaries are modeled (...) 20150320ab. Francisco Huera-Huarte (Universitat Rovira i Virgili) Drag based flapping propulsion with tip pitch control The swimming of fish is characterised by complex kinematics. These kinematics are governed not only by passive bony or cartilaginous structures, but also by active ones and tissue such as muscles. There has been a wide interest in the recent(...) Drag based flapping propulsion with tip pitch control The swimming of fish is characterised by complex kinematics. These kinematics are governed not only by passive bony or cartilaginous structures, but also by active ones and tissue such as muscles. There has been a wide interest in the recent years regarding the understanding of the role of stiffness in flapping (...) Thomas Duriez (Institut Pprime, Poitiers) Close loop control of complex systems : low order linear model approach and nonlinear model free approach Active turbulence control is a rapidly evolving, interdisciplinary field of research. In particular, closed- loop control with sensor information can offer distinct benefits over blind open(...) Close loop control of complex systems : low order linear model approach and nonlinear model free approach Active turbulence control is a rapidly evolving, interdisciplinary field of research. In particular, closed- loop control with sensor information can offer distinct benefits over blind open-loop forcing. The range of current and future engineering applications of closed-loop turbulence control has truly epic (...) Archive 1996-2011 Instructions générales pour les conférenciers Le public du séminaire est très hétérogène (rien qu’au PMMH nous travaillons sur des thématiques très diverses, mécanique des fluides, des milieux granulaires, des solides, physique statistique, physique du mouillage, micro-fluidique, biophysique,...) l’objectif est donc de ne pas faire un séminaire trop spécialiste : au moins la première moitié du séminaire à un niveau accessible pour celui qui ne connaît rien sur le sujet. Le séminaire a lieu à 11h. rendez-vous 15 minutes avant pour installer et tester la projection. Le séminaire dure environ 45 minutes pour laisser un peu de temps pour discuter à la fin. D’autres séminaires en région parisienne : Séminaires ESPCI-ENS de biophysique Séminaires du Département de Physique de l’ENS Séminaires du Laboratoire d’Hydrodynamique de l’X Séminaire de Mécanique d’Orsay (page web FAST) Séminaire de Mécanique d’Orsay (page web LIMSI) Séminaire de Mécanique des Fluides de l’Institut Jean le Rond d’Alembert Séminaires du laboratoire MSC, Paris VII Séminaires Gulliver Lien vers séminaires café (internes, tous les jeudis) Haut de page Séminaires (2) Séminaire PMMH - Alain Goriely, University of Oxford Vendredi 2 juin de 11h00 à 12h00 - Salle réunion PMMH 1 From neurons and sunflowers to elephant trunks : (...) Séminaire PMMH - Orencio Duran (Univ. Texas) Vendredi 9 juin de 11h00 à 12h00 - Salle réunion PMMH 1 Hydrodynamic Origin of Terrestrial “Impact” Ripples (...) Informations Pratiques Laboratoire : 01 40 79 45 22 Directeur : Damien Vandembroucq Codirecteur : Philippe Petitjeans Administratrice : Frédérique Auger (01 40 79 45 22) Gestionnaire : Claudette Barez (01 40 79 58 53) Courriel : Twitter Tweets by @PMMH_lab © ESPCI Paris 2023 Espace privé