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Home page > Séminaires > Archives séminaires > Séminaires 2019 > Séminaire MSC. 18 novembre 2019. Raphaël Jeanneret (LPENS, ENS) : "Hydrodynamics of motile and sinking microorganisms.".

Séminaire MSC. 18 novembre 2019. Raphaël Jeanneret (LPENS, ENS) : "Hydrodynamics of motile and sinking microorganisms."

Sauf mention contraire, les séminaires et les soutenances se déroulent à 11h30 en salle 454A du bâtiment Condorcet.

Title : Hydrodynamics of motile and sinking microorganisms.

Dr. Raphaël Jeanneret Department of Physics of Ecole Normale Supérieure (LabEx ENS-ICFP) Paris

Summary : In this talk I will present the results of two independent projects regarding the physics of micro-organisms. The first study deals with a very large class of non-motile phytoplankton called diatoms. Despite lacking motility we’ll see how these elongated unicellular organisms manage to encounter each other when sinking in quiescent fluids thanks to a hydrodynamically-mediated density instability. Our results pave the way for further investigating the yet poorly understood sexual reproduction that these globally-dominant organisms must occasionally go through to ensure survival of the population. The second project is about the flow disturbances that swimming microorganisms produce when they move near surfaces. As opposed to previous theoretical predictions, we’ll show how the presence of no-slip boundaries enhances the diversity of microbial flow-fields compared to unbounded situations. Such results should be of use to e.g. our understanding of the emergence of collective behaviour in active suspensions in confined situations.

Contact : Équipe séminaires / Seminar team - Published on / Publié le 29 octobre 2019

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