Seminarium organizowane wspólnie przez Wydział Fizyki UW i Pracownię Fizyki Płynów Złożonych IPPT PAN

kolor czcionki + kolor tła = plan do 7 dni.


2019-10-25
 plan 
09:30, Sala: UW, ul. Pasteura 5
prof. dr hab. Alina Ciach
Instytut Chemii Fizycznej PAN

Density Functional Theory for Systems with Competing Interactions

Density functional theory (DFT) for systems with competing interactions leading to self-assembly into clusters, networks or layers is constructed. The contribution to the grand thermodynamic potential associated with mesoscopic fluctuations is explicitly taken into account. The expression for this contribution is obtained by the methods known from the Brazovskii field theory. In addition, we develop a simplified version of the theory valid for weakly ordered phases, i.e. for the high-T part of the phase diagram. The simplified theory is verified by a comparison with the results of simulations for a particular version of the short-range attraction long-range repulsion (SALR) interaction potential. The physical interpretation of the fluctuation-contribution to the grand potential is discussed.

2019-10-18 09:30, Sala: UW, ul. Pasteura 5
Miłosz Panfil
IFT UW

1d quantum liquids and generalised hydrodynamics, part II

The generalised hydrodynamics is a new approach to study strongly correlated quantum matter. It’s an effective theory that captures the low-energy dynamics and extends (generalises) the standard hydrodynamics in the presence of a large number of local conservation laws. It provides insights into equilibration and thermalisation at the quantum level. The presentation will start with a gentle introduction to this theory. In the second part, I will discuss our recent results that on one hand explore the dynamics predicted by GHD and on the other provide some microscopic validations of the theory. Generalised hydrodynamics is an excellent example of how to construct an effective macroscopic theory based on microscopic intuitions.

2019-10-11 09:30, Sala: UW, ul. Pasteura 5
Adolfo Poma
IPPT PAN

Study of the large-scale conformational changes in proteins by Martini force field

The application of coarse-grained (CG) models in biophysics is essentially important due to the large length and time scales involved in the description of several biological processes. The versatile Martini force field allows the CG representation of proteins, sugars and lipids and hence it has been employed in biophysical simulations. The Martini protein model is based on the well-known elastic network (EN) model which maintains the secondary structure of the protein. Such model is inneficient for the sampling of large conformational changes in proteins due to the nature of unbreakable harmonic bonds associated with EN model. To overcome such limitation we have introduced a new description based on a different structure-based CG model. Our model shows a very good agreement with all-atom MD and former Martini protein simulations. Moreover, we show how our model captures the large-scale motion related to the catalytic activity in Man5B protein complex and it results in a smaller number of interactions compared to former Martini protein model description.

2019-10-04 09:30, Sala: UW, ul. Pasteura 5
Miłosz Panfil
IFT UW

1d quantum liquids and generalised hydrodynamics

The generalised hydrodynamics is a new approach to study strongly correlated quantum matter. It’s an effective theory that captures the low-energy dynamics and extends (generalises) the standard hydrodynamics in the presence of a large number of local conservation laws. It provides insights into equilibration and thermalisation at the quantum level. The presentation will start with a gentle introduction to this theory. In the second part, I will discuss our recent results that on one hand explore the dynamics predicted by GHD and on the other provide some microscopic validations of the theory. Generalised hydrodynamics is an excellent example of how to construct an effective macroscopic theory based on microscopic intuitions.

2019-06-07 09:30, Sala: Aula im. Wacława Olszaka, piętro II
prof. Antoine Sellier
LadHyX, Ecole Polytechnique, Palaiseau, France.

Creeping flow about solid particles taking a slip boundary condition

We show how a boundary approach is able to efficiently and accurately deal with the Stokes flow around a collection of solid particles on which the usual no-slip boundary condition is not relevant and is replaced either with a Smoluchowski (electrophoresis case) or a Navier slip boundary condition.