SFB Colloquium Guest Talk Abstract - 2017/2018 - Schubotz

Wiebke Schubotz, Max Planck Institute for Meteorology, Hamburg

High definition clouds and precipitation - an overview of the HD(CP)² project

The project HD(CP)² (High Definition Clouds and Precipitation for advancing Climate Prediction) addresses the lack of understanding of cloud and precipitation (CP) processes, which is one of the foremost problems of climate simulations and climate predictions. In its first funding phase, the project leveraged rapid developments in simulation and measurement science (through its modeling and observation modules) and thus provided new insights to resolve the CP roadblock. This resulted in a significantly improved representation of clouds and precipitation in the ICON (Icosahedral non-hydrostatic) model that is used for hindcast simulations in HD(CP)². This model is currently utilized on a scale of 150m horizontal resolution over regions so diverse as central Europe, the Tropical and the Northern Atlantic. In its second funding phase, the work of the modeling and observation modules is utilized in several synthesis modules that investigate various topics such as the fast cloud adjustments to aerosols, convective organization of clouds or the influence of land surface heterogeneity. Data from observation campaigns is made available through the project own data base SAMD to the scientific community.

SFB Colloquium Guest Talk Abstract - 2017 - Settanni

Giovanni Settanni, Junior faculty Max-Planck Graduate Center, Physics Department, University of Mainz:

Nano-bio interfaces investigated using molecular dynamics simulations

The effectiveness of drugs and, more in general, therapeutic agents (therapeutic proteins, liposomes, nanoparticles, medical implants etc.) is strongly influenced by the interface they form with the surrounding biological fluids. For example, the protein shell (corona) forming around nanoparticles in contact with blood is a major factor in determining their circulation half-time and immuno- and thrombogenicity. The composition of the layer of adsorbed proteins, their structure and orientation all play a fundamental role in the reaction of the organism to the therapeutic agent. However, the molecular factors at the base of these interactions are not yet very well understood. Classical molecular dynamics simulations can be used to evaluate the interactions of proteins with (nano-) materials. Here, I will present how we used this technique to study the adsorption on model surfaces of fibrinogen, a protein involved in blood coagulation, and the adsorption of plasma proteins on nanoparticles coated with hydrophilic polymers. In both cases, the simulations provide a molecular-level picture of the adsorption process which can then be used to build more general models of protein adsorption and compared with experimental data.

SFB Colloquium Talk Abstract - 2017 - Blum

Dr. Alexander Blum, Max Planck Institute for the History of Science

Relativity after Einstein

In November 1915, Albert Einstein published his theory of gravitation, thus attaining international renown which was to last unfailingly until the present day, long after his death. The history of his general theory of relativity, however, took a different course. After the initial hype, interest in and research into the theory ebbed, resurfacing only ca. 50 years later, around 1960, in what is commonly referred to as the “renaissance” of general relativity. Only in this period did general relativity become a research field in its own right (with conferences and journals) and were essential concepts developed that we now strongly associate with Einstein’s theory, such as the black hole. In my talk, I will follow this development, asking why it took so long for Einstein’s theory to mature, what finally led to its breakthrough, and what that teaches us about scientific revolutions and theory change.

SFB Colloquium Talk Abstract - 2017 - Rosenau & Heida

Matthias Rosenau, Helmholtz Center, Potsdam  &  Martin Heida, WIAS Berlin

Matthias Rosenau: "What is ... Particle Image Velocimetry?"

Particle Image Velocimetry (PIV) is a visualization method for quantitative flow and deformation analysis. PIV is a key method used in the experiments of project B01 and, in this framework, supported by the DFG by means of a 80 k€ infrastrutural investment. PIV is based on digital image correlation and signal processing techniques. The output is basically a velocity field, in case of project B01, that of an experimentally simulated earth surface during earthquake cycles. I will give a quick overview of technical issues and applications.

Martin Heida: "What is ... GENERIC?"

We give a short introduction into the fundamental idea of the "General Equation for the NonEquilibrium Reversible-Irreversible Coupling", called GENERIC, and apply it to gain new insights into the well-established model of rate-and-state friction in geology.

SFB Colloquium Talk Abstract - 2017 - Bittracher & Koltai

Andreas Bittracher & Péter Koltai, Freie Universität Berlin:

"What is … a transition manifold and reaction coordinates?"

We consider complex dynamical systems showing metastable behavior but no local separation of fast and slow time scales, and raise the question whether such systems exhibit a low-dimensional manifold supporting its effective dynamics. For answering this question, we aim at finding nonlinear coordinates, called reaction coordinates, such that the projection of the dynamics onto these coordinates preserves the dominant time scales of the dynamics.
We show that, based on a specific reducibility property, the existence of good low-dimensional reaction coordinates preserving the dominant time scales is guaranteed. Based on this theoretical framework, we develop a novel numerical approach for computing good reaction coordinates. The proposed algorithmic approach is fully local and thus not prone to the curse of dimension with respect to the state space of the dynamics. Hence, it is a promising method for data-based model reduction of complex dynamical systems such as molecular dynamics.

Back to top