Vortrag 1:

Strong correlation effects in real materials

Referentin:

Prof. Dr. Eva Pavarini, IAS-3

Inhalt:

Soon after the discovery of quantum mechanics, it is became evident that the major obstacle to explaining the properties of solids from first principles is the description of electronic many-body effects. Understanding strong correlations in real materials remains to date one of the grand challenges in condensed-matter physics. To address this problem, during the last years conventional ab-initio schemes based on density-functional theory, have been merged with a modern many-body approach, the dynamical mean-field theory, into a new computational method known as LDA+DMFT.
We show how, by using this novel approach and exploiting the power of modern supercomputers, we identify the mechanism of orbital ordering in manganites and cuprates, thus solving a long-standing problem.

Vortrag 2:

Blood rheology, blood cell interactions and migration in micro-vessels

Referent:

Dr. Dmitry Fedosov, ICS-2

Inhalt:

Blood flow in microcirculation strongly affects many physiological processes and pathologies in the organism. To understand these processes, detailed investigation of blood flow under realistic conditions is required. Blood exhibits a shear-thinning behavior, which is governed by viscoelastic properties of red blood cells (RBCs), their concentration and interactions (e.g., RBC aggregation). In addition, blood flow in microcirculation is further complicated by migration of the cells. We employ the Dissipative Particle Dynamics method to model blood as a suspension of deformable cells represented by a viscoelastic spring-network which incorporates appropriate mechanical and rheological cell-membrane properties. Blood rheology as well as blood flow in idealized micro-channel geometries will be investigated. We will discuss blood rheological properties, blood flow resistance and Fahraeus-Lindqvist effect, cell migration and distribution in the flow with respect to various conditions such as hematocrit, flow rate, and RBC aggregation. Moreover, we will discuss the relation between blood rheology and RBC dynamics and structure, and the physical mechanisms which govern white blood cell margination towards the walls in micro-vessels.