Soft Matter and Complex Systems Seminar
2006/2007 | 2007/2008 | 2008/2009 | 2009/2010 | 2010/2011 | 2011/2012 | 2012/2013 | 2013/2014 | 2014/2015 | 2015/2016 | 2016/2017 | 2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024
2015-06-12 (Friday)
room 1.02, Pasteura 5 at 09:30 
Michał Pecelerowicz (IFT UW)(In)stability of Laplacian growth
2015-05-29 (Friday)
room 1.02, Pasteura 5 at 09:30
Piotr Zdybel (Wydział Fizyki UW)Nieperturbacyjne sformułowanie teorii renormalizacji
W trakcie wystąpienia zostanie zaprezentowane nieperturbacyjne podejście do procedury renormalizacji Wilsona zaproponowane w 1993 roku przez Wettericha. Metoda Wettericha polega na skonstruowaniu rodziny funkcjonałów parametryzowanej wektorem falowym k, dla których można wyprowadzić równanie płynięcia ze względu na k odpowiadające w procedurze Wilsona eliminacji modów. Wystąpienie będzie miało charakter przeglądowy i w jego trakcie zostaną zaprezentowane obliczenia dla modelu O(1) znajdującego się w klasie uniwersalności modelu Isinga.
2015-05-22 (Friday)
room 1.02, Pasteura 5 at 09:30
dr Magdalena Gruziel (IFT UW)On the estimation of chirality and scale dependent chirality of biomolecules
Chirality is a property initially created for molecules - two chiral isomers of one molecule are mirror images of themselves. In the seminar I will present several approaches to estimate the chirality both experimentally and theoretically with examples of some of them. There are several problems connected with either the psaudoscalar type of chirality index, which leads to so called chiral zeros, or the resolution of discretization of studied chiral curve, which can be depicted as chirality spectrum. I will try to explain the latter issues using geometrical or molecular examples.
2015-05-15 (Friday)
room 1.02, Pasteura 5 at 09:30
mgr Marta Gruca (IPPT PAN)Dynamics of regular systems of many particles falling under gravity in a viscous fluid
Dynamics of a cluster of non-Brownian particles falling under gravity in a viscous fluid at low-Reynolds-number regime has been extensively studied in the literature both for small and large number of particles and oscillating motions have been discovered. In this work, we investigate dynamics of clusters of many non-Brownian particles in regular configurations settling under gravity in a viscous fluid. The point particle approximation is applied for the hydrodynamic interactions. We find out that a wide range of regular initial configurations of many particles leads to very long lifetime of the cluster with periodic and quasi-periodic relative motion of particles. We vary the relative distance between the particles and observe how does it affect the dynamics. Several types of periodic and quasi-periodic solutions are discovered, or the system break up. For broad range of initial configurations we show that a slight change of initial conditions has a large influence on the system lifetime - we observe chaotic scattering.
2015-04-24 (Friday)
room 1.02, Pasteura 5 at 09:30
Karol Wędołowski (IFT UW)Interaction of a gas-liquid interface with a moving perturbation
In the presentation I will discuss the problem of interaction between a gas-liquid interface and a small object moving in its vicinity. In particular, I will present the concept of a wave resistance, which is an important quantity in a number of macroscopic systems. On the other hand, on a microscale, deformation of a gas-liquid interface caused by a moving object can be relevant for a capillary bridge formation. I will discuss this problem in the context of relevant length and time scales, which play a crucial role in the description of the dynamic deformation of a gas-liquid interface.
2015-04-10 (Friday)
room 1.02, Pasteura 5 at 09:30
Paweł Sznajder (IFT UW)Effective steady Stokes equation for a suspension
In this talk I will discuss the derivation of the effective steady Stokes equation for a suspension of rigid particles immersed in an incompressible viscous fluid on timescale much larger than the characteristic time of viscous relaxation. I will show how to manage all nonintegrable terms so that one can derive local equations and has a tool to deal with macroscopic flow of the suspension.
2015-03-27 (Friday)
room 1.02, Pasteura 5 at 09:30
prof. Ryszard Kutner (IFD UW)Continuous-Time Random Walk & Extreme Value Theory as a principle statistic physics tools in analysis of interoccurrence times between excessive losses in financial markets
The problem of the excessive losses is a central one (both from theoretical and practical points of view) in market activity. The goal of the talk is to present a consistent desription of empirical data (supplied in this context by Ludescher, Tsallis and Bunde [1,2]) by the Continuous-Time Random Walk (CTRW) & Extreme Value Theory (EVT) supported by the postional statistics. We found that superstatistics, defined by the convolution of the Weibull distribution and the Poisson one based on the stretched exponential relaxation time, derived within the CTRW & EVT, consistently described the „universal” statistics of interoccurrence times between excessive losses on financial markets, despite the fact that these data were already earlier described in part by q-exponential. We believe that our approach gives also an input to study autocorrelations between these interoccurrence times.
[1] J. Ludescher, C. Tsallis and A. Bunde: Universal bevaviour of interoccurrence times between losses in financial markets: An analytical description, EPL 95 (2011) 68002.
[2] J. Ludescher and A. Bunde: Universal bevavior of interoccurrence times between losses in financial markets: Independence of the time resolution, Phys. Rev. E 90 (2014) 062809.
[1] J. Ludescher, C. Tsallis and A. Bunde: Universal bevaviour of interoccurrence times between losses in financial markets: An analytical description, EPL 95 (2011) 68002.
[2] J. Ludescher and A. Bunde: Universal bevavior of interoccurrence times between losses in financial markets: Independence of the time resolution, Phys. Rev. E 90 (2014) 062809.
2015-03-13 (Friday)
room 1.02, Pasteura 5 at 09:30
Katarzyna Karpińska (IGF UW)Inertial heavy droplets in vortices with stretching
Many studies attribute the evolution of droplet size distribution in warm, convective clouds to enhancement of collision-coalescence by turbulence. One of the effects of turbulence on droplets is preferential concentration. In order to analyze one of mechanisms leading to preferential concentration we investigate motion of droplets, governed by viscosity and gravity only, in prescribed line and Burgers vortices. Such vortices are often considered reasonable models of thin and long vortex tubes present in high Reynolds number turbulence. Both analytical and numerical solutions of droplet motion allow to identify stationary points, stationary orbits and limit cycles, which influence spatial distribution of droplets and effectively sort polydysperse particles.
2015-03-06 (Friday)
room 1.02, Pasteura 5 at 09:30
dr Filip Dutka (IChF PAN)A simple approach to forming long conductive pearl-chains by utilizing dipolar and capillary interactions
I will talk about method of forming long conductivepearl-chains which is under development. In this method capillary andelectrorheological phenomena play the essential roles. As far ascapillary contribution is quite well undestood, electric part ischallenging. The seminar will have working character with more posedthan answered questions.
2015-02-27 (Friday)