From Maciej.Lisicki at fuw.edu.pl Mon Dec 4 21:47:49 2023 From: Maciej.Lisicki at fuw.edu.pl (Maciej Lisicki) Date: Mon, 4 Dec 2023 21:47:49 +0100 Subject: [Soft-matter] Soft Matter & Complex Systems Seminar on 8 Dec 2023 Message-ID: <8DF58F40-C09E-4F5D-AACF-01A699998FF1@fuw.edu.pl> Dear Soft Matter & Complex Systems Colleagues and Friends, On Friday 8 December 2023 at 9:30 AM at the UW Faculty of Physics (Pasteura 5, Warsaw; room 1.40) we are hosting a seminar during which Bogdan Cichocki & Jeffrey Everts (FUW) will give a talk Chiral active fluids in the creeping flow regime (Part II) Abstract Viscosity is a property that tells us how easy it is to cause flow in a fluid. For incompressible isotropic systems, the most well-known type of viscosity is the shear viscosity, which quantifies how much of the fluid's available energy dissipates when a symmetric velocity gradient is induced into the system. However, the situation differs in so-called chiral active fluids, which are manifestly out-of-equilibrium systems. Here, the fluid particles are set into motion by activity or uniform rotation of the system and are, therefore, characterised by a non-trivial angular momentum density. Consequently, the flow properties of such a fluid are not just described by the shear viscosity. There are additional so-called odd viscosity coefficients that do not contribute to viscous dissipation in a direct manner. Because of the fundamental interest in this problem and recent experiments, we study such chiral active fluids in the creeping flow regime in more detail. In Part 1 of the seminar (1 December), we show that the fundamental solution can be explicitly constructed without any approximation for stationary three-dimensional incompressible flow. Our calculations form the basis for solving more complicated flow problems and for constructing the theory of hydrodynamic interactions in chiral active fluids. In Part 2 of the talk (8 December), we will demonstrate how we can use the Green's function to construct an analytical exact solution for the single-particle problem. Furthermore, we will then explicitly demonstrate that odd viscosity can contribute to viscous dissipation via alteration of the fluid flow. We warmly welcome everyone to attend the talk and the Soft Matter Coffee Break after the seminar, held in room 2.63 (2nd floor). Maria Ekiel-Je?ewska Maciej Lisicki Piotr Szymczak Panagiotis Theodorakis Marek Trippenbach -------------- next part -------------- An HTML attachment was scrubbed... URL: From Maciej.Lisicki at fuw.edu.pl Mon Dec 11 08:49:07 2023 From: Maciej.Lisicki at fuw.edu.pl (Maciej Lisicki) Date: Mon, 11 Dec 2023 08:49:07 +0100 Subject: [Soft-matter] Soft Matter & Complex Systems Seminar on 15 Dec 2023 Message-ID: <47975B78-6AD3-40CF-882D-884B77454DC3@fuw.edu.pl> Dear Soft Matter & Complex Systems Colleagues and Friends, On Friday 15 December 2023 at 9:30 AM at the UW Faculty of Physics (Pasteura 5, Warsaw; room 1.40) we are hosting the last seminar of this calendar year. Our speaker will be Piotr Sur?wka (Institute of Theoretical Physics, Wroc?aw University of Science and Technology) who will give a talk Odd Viscoelasticity Abstract Active matter encompasses systems that are not in equilibrium, consisting of elements that either consume energy or exert work. Consequently, their macroscopic characteristics diverge significantly from those predicted by continuum field theories based on equilibrium statistical mechanics. Recent advancements in active matter research have prompted a reevaluation of the fundamental principles of materials science. This has led to the development of a novel theoretical framework known as odd (visco)elasticity. Traditional elasticity treats solids as continuous media that change shape in response to external forces. On a microscopic scale, applying force to a crystalline structure displaces its atoms, which then exert a counterforce to regain the crystal's original configuration. However, this dynamic is fundamentally altered in active odd materials, where the response to applied forces includes not only compression or deformation but also deflection. In this presentation, I will provide an overview of the recent advancements in this field. We warmly welcome everyone to attend the talk and the Soft Matter Coffee Break after the seminar, held in room 2.63 (2nd floor). After this event, our seminars will resume on 12 January 2024. Maria Ekiel-Je?ewska Maciej Lisicki Piotr Szymczak Panagiotis Theodorakis Marek Trippenbach -------------- next part -------------- An HTML attachment was scrubbed... URL: