A5044827336- Solidification and crystal growth phenomena
- Micro and Nano Robotics
- Fluid Dynamics and Thin Films
- nanoparticles nucleation surface interactions
- Theoretical and Computational Physics
- Advanced Numerical Methods in Computational Mathematics
- Aluminum Alloy Microstructure Properties
- Advanced Mathematical Modeling in Engineering
- Cellular Mechanics and Interactions
- Silicon and Solar Cell Technologies
- Liquid Crystal Research Advancements
- Lattice Boltzmann Simulation Studies
- Advanced Materials and Mechanics
- Fluid Dynamics and Turbulent Flows
- Computational Fluid Dynamics and Aerodynamics
- Rheology and Fluid Dynamics Studies
- Thin-Film Transistor Technologies
- Nonlinear Dynamics and Pattern Formation
- Microstructure and mechanical properties
- Surface Modification and Superhydrophobicity
- Pickering emulsions and particle stabilization
- Advanced Numerical Analysis Techniques
- Material Dynamics and Properties
- Fluid Dynamics and Heat Transfer
- Lipid Membrane Structure and Behavior
TU Dresden
2016-2025
Center for Systems Biology Dresden
2015-2025
Excellence Cluster Universe
2019-2023
Technical University of Munich
2020
Norwegian University of Science and Technology
2009
Center of Advanced European Studies and Research
2001-2008
University of Potsdam
2007
Friedensau Adventist University
2002
Friedrich-Alexander-Universität Erlangen-Nürnberg
1990-1998
University of Toronto
1991-1993
Springtails (Collembola) are wingless arthropods adapted to cutaneous respiration in temporarily rain-flooded habitats. They immediately form a plastron, protecting them against suffocation upon immersion into water and even low-surface-tension liquids such as alkanes. Recent experimental studies revealed high-pressure resistance of plastrons collapse. In this work, skin sections Orthonychiurus stachianus studied by transmission electron microscopy. The micrographs reveal cavity side-wall...
We extend previous work and present a general approach for solving partial differential equations in complex, stationary, or moving geometries with Dirichlet, Neumann, Robin boundary conditions. Using an implicit representation of the geometry through auxilliary phase field function, which replaces sharp domain diffuse layer (e.g. domain), equation is reformulated on larger regular domain. The resulting same order as original equation, additional lower terms to approximate can be solved by...
The phase-field-crystal model is by now widely used in order to predict crystal nucleation and growth. For colloidal solidification with completely overdamped individual particle motion, we show that the dynamics can be derived from microscopic Smoluchowski equation via dynamical density-functional theory. different underlying approximations are discussed. In particular, a variant of proposed which involves less than standard model. We finally test validity these models against velocities...
We develop a thermodynamically consistent phase-field model to simulate the dynamics of multicomponent vesicles. The accounts for bending stiffness, spontaneous curvature, excess (surface) energy, and line tension between coexisting surface phases. Our approach is similar that recently used by Wang Du [J. Math. Biol. 56, 347 (2008)] with key difference. Here, we concentrate on dynamic evolution solve mass conservation equation explicitly; this was not considered Du. resulting fourth-order...
We present a new phase-field model for strongly anisotropic crystal and epitaxial growth using regularized, Cahn–Hilliard-type equations. Such problems arise during the coarsening of thin films. When surface energy is sufficiently strong, sharp corners form unregularized Cahn–Hilliard equations become ill-posed. Our models contain high-order Willmore regularization, where square mean curvature added to energy, remove ill-posedness. The regularized are sixth order in space. A key feature our...
SUMMARY Diffuse interface models for incompressible two‐phase flow with large density ratios are tested on benchmark configurations a two‐dimensional bubble rising in liquid columns. The quantities circularity, center of mass, and mean rise velocity compared reference solutions from Hysing et al . Copyright © 2011 John Wiley & Sons, Ltd.
Springtails (Collembola) are wingless arthropods adapted to cutaneous respiration in temporarily rain-flooded and microbially contaminated habitats by a non-wetting antiadhesive skin surface that is mechanically rather stable. Recapitulating the robust effectively repellent characteristics of springtail engineered materials may offer exciting opportunities for demanding applications, but it requires detailed understanding underlying design principles. Towards this aim based on our recent...
Si-based nanoarchitectures are formed with unprecedented precision and reproducibility via templated dewetting of thin SOI.
We introduce a new approach to deal with the numerical solution of partial differential equations on surfaces.Thereby we reformulate problem larger domain in one higher dimension and diffuse interface region phase-field variable, which is defined whole domain.The surface interest now only implicitly given by 1/2-level set this variable.Formal matched asymptotics show convergence reformulated original PDE surface, as width shrinks zero.The main advantage possibility formulate Cartesian...
A method is presented to solve two-phase problems involving a material quantity on an interface. The interface can be advected, stretched, and change topology, adsorbed or desorbed from it. based the use of diffuse framework, which allows simple implementation using standard finite-difference finite-element techniques. Here, methods block-structured adaptive grid are used, resulting equations solved non-linear multigrid method. Interfacial flow with soluble surfactants used as example...
Abstract A two-phase Newtonian surface fluid is modelled as a Cahn–Hilliard–Navier–Stokes equation using stream function formulation. This allows one to circumvent the subtleties in describing vectorial second-order partial differential equations on curved surfaces and for an efficient numerical treatment parametric finite elements. The approach validated various test cases, including vortex-trapping demonstrating strong interplay of morphology flow. Finally applied Rayleigh–Taylor...
Several crystalline structures are metastable or kinetically frozen out-of-equilibrium states in the phase space. When corresponding lifetime is sufficiently long, typical equilibrium features such as regular and extended faceting can be observed. However, interpreting extension of facets overall shape terms a standard Wulff analysis not justified. Here, we introduce convenient general formulation anisotropic surface energy density, combined with suitable phase-field model diffusion. This...
Incompressible fluids on curved surfaces are considered with respect to the interplay between topology, geometry, and fluid properties using a surface vorticity-stream function formulation, which is solved parametric finite elements. Motivated by designed examples for superfluids, we numerically consider influence of geometric potential vortices viscosity show in change geometry used manipulate flow field.
We demonstrate that the complex spatiotemporal structure in active fluids can feature characteristics of hyperuniformity. Using a hydrodynamic model, we show transition from hyperuniformity to nonhyperuniformity and antihyperuniformity depends on strength forcing be related features turbulence without with scaling inertial turbulence. Combined identified signatures Levy walks nonuniversal diffusion these systems, this allows for biological interpretation speculation nonequilibrium...
We review the derivation of a phase field crystal (PFC) model from classical density functional theory (DFT). Through gradient flow Helmholtz free energy and appropriate approximations correlation functions, higher order nonlinear equations are derived for evolution time averaged density. The equation is solved by finite elements using semi-implicit discretization.