@misc{BestehornBestehornMichelitschetal., author = {Bestehorn, Michael and Bestehorn, Michael and Michelitsch, Thomas M. and Collet, Bernard A. and Riascos, Alejandro P. and Nowakowski, Andrzej. F.}, title = {Simple model of epidemic dynamics with memory effects}, series = {Physical Review E}, volume = {105}, journal = {Physical Review E}, number = {2}, issn = {2470-0045}, doi = {10.1103/PhysRevE.105.024205}, pages = {024205-1 -- 024205-10}, abstract = {We introduce a compartment model with memory for the dynamics of epidemic spreading in a constant population of individuals. Each individual is in one of the states S=susceptible, I=infected, or R=recovered (SIR model). In state R an individual is assumed to stay immune within a finite-time interval. In the first part, we introduce a random lifetime or duration of immunity which is drawn from a certain probability density function. Once the time of immunity is elapsed an individual makes an instantaneous transition to the susceptible state. By introducing a random duration of immunity a memory effect is introduced into the process which crucially determines the epidemic dynamics. In the second part, we investigate the influence of the memory effect on the space-time dynamics of the epidemic spreading by implementing this approach into computer simulations and employ a multiple random walker's model. If a susceptible walker meets an infectious one on the same site, then the susceptible one gets infected with a certain probability. The computer experiments allow us to identify relevant parameters for spread or extinction of an epidemic. In both parts, the finite duration of immunity causes persistent oscillations in the number of infected individuals with ongoing epidemic activity preventing the system from relaxation to a steady state solution. Such oscillatory behavior is supported by real-life observations and not captured by the classical standard SIR model.}, language = {en} } @misc{VarlamovaReifStolzetal., author = {Varlamova, Olga and Reif, J{\"u}rgen and Stolz, Michael and Borcia, Rodica and Borcia, Ion-Dan and Bestehorn, Michael}, title = {Wetting properties of LIPSS structured silicon surfaces}, series = {The European Physical Journal B}, volume = {92}, journal = {The European Physical Journal B}, number = {5}, issn = {1434-6036}, doi = {10.1140/epjb/e2019-90672-2}, pages = {8}, abstract = {The controlled dynamics of liquid drops via generation of specific wetting states on a solid surface is of great interests both in the fundamental and applied sciences. Considering that the wettability is strongly dependent on the surface topography and surface roughness, we investigate - through experiments and theory - the effect of laser-induced periodic surface structures (LIPSS) generated on silicon (100) targets as a control parameter of wetting properties. To obtain structured silicon surfaces with different morphological features, we patterned the surface by irradiation with femtosecond pulses from an amplified Ti:Sapphire laser system (790 nm/100 fs/1 kHz) at a fluence in the range of 0.4-1.2 J/cm2 on a spot with a diameter about of 100 μm. Variation of the applied irradiation dose results in surface modifications with the roughness about of a few tens of nanometers are ranging from regular LIPSS patterns with the lateral period of about 500-700 nm to complex agglomerations of 3-D microstructures with several-μm feature size. The theoretical study on the correlation of wetting properties with the surface topography has been performed within a phase field model. We found an excellent agreement of numerical results with experiments.}, language = {en} } @article{BestehornNeuffer, author = {Bestehorn, Michael and Neuffer, Kai}, title = {Surface Patterns of Laterally Extended Thin Liquid Films in Three Dimensions}, series = {Physical review letters}, volume = {87}, journal = {Physical review letters}, number = {4}, issn = {1079-7114}, pages = {046101}, language = {en} } @article{BestehornMerktEnculescu, author = {Bestehorn, Michael and Merkt, Domnic and Enculescu, Mihaela}, title = {Entstehung und Dynamik makroskopischer Strukturen in Systemen fern vom Gleichgewicht}, series = {Forum der Forschung}, volume = {9}, journal = {Forum der Forschung}, number = {18}, issn = {0947-6989}, pages = {31 -- 40}, language = {de} } @misc{VarlamovaCostacheReifetal., author = {Varlamova, Olga and Costache, Florenta Adriana and Reif, J{\"u}rgen and Bestehorn, Michael}, title = {Self-organized pattern formation upon femtosecond laser ablation by circularly polarized light}, series = {Applied Surface Science}, volume = {252}, journal = {Applied Surface Science}, number = {13}, issn = {0169-4332}, pages = {4702 -- 4706}, language = {en} } @incollection{BestehornHaken, author = {Bestehorn, Michael and Haken, H.}, title = {Pattern Formation and Transients in the Convection Instability}, language = {en} } @incollection{BestehornFriedrichHaken, author = {Bestehorn, Michael and Friedrich, R. and Haken, H.}, title = {Modulated Traveling Waves in Nonequilibrium Systems}, language = {en} } @article{Bestehorn, author = {Bestehorn, Michael}, title = {Stationary and Traveling Pulses of the 2D Complex Ginzburg-Landau Equation}, language = {en} } @article{BestehornFantzFriedrichetal., author = {Bestehorn, Michael and Fantz, M. and Friedrich, R. and Haken, H. and P{\´e}rez-Garc{\´i}a, C.}, title = {Spiral Patterns in Thermal Convection}, language = {en} } @article{BestehornFantzFriedrichetal., author = {Bestehorn, Michael and Fantz, M. and Friedrich, R. and Haken, H.}, title = {Pattern formation in rotating B{\´e}nard convection}, language = {en} } @article{BestehornPerezGarcia, author = {Bestehorn, Michael and P{\´e}rez-Garc{\´i}a, C.}, title = {Coexistence of Patterns with Different Symmetries in B{\´e}nard-Marangoni Convection}, language = {en} } @article{ThessBestehorn, author = {Thess, A. and Bestehorn, Michael}, title = {Planform Selection in B{\´e}nard-Marangoni-Convection: l-hexagons versus g-hexagons}, language = {en} } @article{PerezGarciaEchebarriaBestehorn, author = {P{\´e}rez-Garc{\´i}a, C. and Echebarria, B. and Bestehorn, Michael}, title = {Thermal Properties in Surface-Tension-Driven Convection}, language = {en} } @inproceedings{VaerenberghLegrosColinetetal., author = {Vaerenbergh, S. van and Legros, J. C. and Colinet, P. and Velarde, M. G. and Bestehorn, Michael and Lebon, G. and Thess, A. and Karcher, C.}, title = {Processes With Double Diffusive Instabilities Studied in Microgravity}, series = {The 2nd European Symposium on Utilisation of the International Space Station, 16 - 18 November 1998, ESTEC, Noordwijk, The Netherlands}, booktitle = {The 2nd European Symposium on Utilisation of the International Space Station, 16 - 18 November 1998, ESTEC, Noordwijk, The Netherlands}, publisher = {ESA Publ.}, address = {Noordwijk}, isbn = {92-9092-732-1}, pages = {241 -- 248}, language = {en} } @article{BestehornFantzFriedrichetal., author = {Bestehorn, Michael and Fantz, M. and Friedrich, R. and Haken, H.}, title = {Hexagonal and Spiral Patterns of Thermal Convection}, language = {en} } @article{BestehornNeufeldFriedrichetal., author = {Bestehorn, Michael and Neufeld, M. and Friedrich, R. and Haken, H.}, title = {Pattern formation in rotating B{\´e}nard convection}, language = {en} } @article{HerreroPerezGarciaBestehorn, author = {Herrero, H. and P{\´e}rez-Garc{\´i}a, C. and Bestehorn, Michael}, title = {Stability of fronts separating domains with different symmetries in hydrodynamical instabilities}, language = {en} } @incollection{BestehornFriedrich, author = {Bestehorn, Michael and Friedrich, R.}, title = {Natural Patterns in Nonequilibrium Systems, in A Perspective Look at Nonlinear Media - From Physics to Biology and Social Sciences}, language = {en} } @article{BestehornFriedrich, author = {Bestehorn, Michael and Friedrich, R.}, title = {Rotationally invariant order parameter equations for natural patterns in nonequilibrium systems}, language = {en} } @article{ThieleVelardeNeufferetal., author = {Thiele, Uwe and Velarde, M. G. and Neuffer, Kai and Bestehorn, Michael and Pomeau, Y.}, title = {Sliding drops in the diffusive interface model coupled to hydrodynamics}, series = {Physical Review E}, volume = {64}, journal = {Physical Review E}, number = {4}, issn = {1550-2376}, pages = {061601}, language = {en} } @article{ThieleNeufferBestehornetal., author = {Thiele, Uwe and Neuffer, Kai and Bestehorn, Michael and Pomeau, Y. and Velarde, M. G.}, title = {Sliding drops on an inclined plane}, series = {Colloids and Surfaces A}, volume = {206}, journal = {Colloids and Surfaces A}, number = {1-3}, pages = {87 -- 104}, language = {en} } @article{BestehornPototskyThiele, author = {Bestehorn, Michael and Pototsky, Andrey and Thiele, Uwe}, title = {3D Large scale Marangoni convection in liquid films}, language = {en} } @article{ThieleBruschBestehornetal., author = {Thiele, Uwe and Brusch, L. and Bestehorn, Michael and B{\"a}r, Marcus}, title = {Modelling thin-film dewetting on structured substrates and templates}, language = {en} } @article{PototskyBestehornThiele, author = {Pototsky, Andrey and Bestehorn, Michael and Thiele, Uwe}, title = {Control of the structuring of thin softmatter films by means of different types of external disturbance}, language = {en} } @article{NitschkeBestehornThess, author = {Nitschke, K. and Bestehorn, Michael and Thess, A.}, title = {Square Cells in Surface-Tension-Driven B{\´e}nard Convection}, language = {en} } @article{BestehornColinet, author = {Bestehorn, Michael and Colinet, P.}, title = {B{\´e}nard-Marangoni convection of a binary mixture as an example of an oscillatory bifurcation under strong symmetry-breaking effects}, series = {Physica D: Nonlinear Phenomena}, volume = {145}, journal = {Physica D: Nonlinear Phenomena}, number = {1-2}, issn = {1872-8022}, pages = {84 -- 109}, language = {en} } @article{MerktBestehorn, author = {Merkt, Domnic and Bestehorn, Michael}, title = {B{\´e}nard-Marangoni convection in a stronglyevaporating fluid}, language = {en} } @article{ColinetJoannesIorioetal., author = {Colinet, P. and Joannes, L. and Iorio, C. S. and Haut, B. and Bestehorn, Michael and Lebon, G. and Legros, J. C.}, title = {Interfacial turbulence in evaporating liquids: Theory and preliminary results of the ITEL-Master 9 sounding rocket experiment}, language = {en} } @article{BorciaMerktBestehorn, author = {Borcia, Rodica and Merkt, Domnic and Bestehorn, Michael}, title = {A phase-field description of surface-tension-driven instability}, language = {en} } @article{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {Phase-field simulations for evaporation with convection in liquid-vapor systems}, series = {The European physical journal B}, volume = {44}, journal = {The European physical journal B}, number = {1}, issn = {1434-6028}, pages = {101 -- 108}, language = {en} } @article{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {Phase field models for Marangoni convection in planar layers}, language = {en} } @article{BorciaMerktBestehorn, author = {Borcia, Rodica and Merkt, Domnic and Bestehorn, Michael}, title = {Convective patterns in liquid-vaporsystems with diffuse interface}, language = {en} } @article{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {Phase field models and Marangoni flows}, language = {en} } @article{MillanRodriguezPerezGarciaBestehornetal., author = {Mill{\´a}n-Rodriguez, J. and P{\´e}rez-Garc{\´i}a, C. and Bestehorn, Michael and Fantz, M. and Friedrich, R.}, title = {Pattern Formation in Convection of Rotating Fluids with Broken Vertical Symmetry}, language = {en} } @article{Bestehorn, author = {Bestehorn, Michael}, title = {Numerical Results of 3D Stationary Convection in a Binary Mixture}, language = {en} } @article{Bestehorn, author = {Bestehorn, Michael}, title = {Phase and Amplitude Instabilities for B{\´e}nard-Marangoni Convection in Fluid Layers with Large Aspect Ratio}, language = {en} } @article{Bestehorn, author = {Bestehorn, Michael}, title = {Pattern Selection in B{\´e}nard-Marangoni Convection}, language = {en} } @article{MillanRodriguezBestehornPerezGarciaetal., author = {Mill{\´a}n-Rodriguez, J. and Bestehorn, Michael and P{\´e}rez-Garc{\´i}a, C. and Friedrich, R. and Neufeld, M.}, title = {Defects Motion in Rotating Fluids}, language = {en} } @misc{Bestehorn, author = {Bestehorn, Michael}, title = {Square Patterns in B{\´e}nard-Marangoni Convection}, language = {en} } @article{Bestehorn, author = {Bestehorn, Michael}, title = {Two Layer Model Showing a Variety of Pattern Types near Nonequilibrium Phase Transitions}, language = {en} } @misc{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {Different behaviours of delayed fusion between drops with miscible liquids}, series = {Physical review E}, volume = {82}, journal = {Physical review E}, number = {3}, issn = {1063-651X}, pages = {036312}, language = {en} } @article{BestehornGrigorievaHakenetal., author = {Bestehorn, Michael and Grigorieva, E. V. and Haken, H. and Kaschenko, S. A.}, title = {Order Parameters for Class-B Lasers With a Long Time Delayed Feedback}, language = {en} } @article{BestehornGrigorievaKaschenko, author = {Bestehorn, Michael and Grigorieva, E. V. and Kaschenko, S. A.}, title = {Spatio-Temporal Structures in a Model With Delay And Diffusion}, language = {en} } @article{BestehornGrigorieva, author = {Bestehorn, Michael and Grigorieva, E. V.}, title = {Formation and Propagation of Localized States in Extended Systems}, language = {en} } @article{BestehornPerezGarcia, author = {Bestehorn, Michael and P{\´e}rez-Garc{\´i}a, C.}, title = {Modulated Rolls and Traveling Waves in a Secondary Convective Instability}, language = {en} } @article{Bestehorn, author = {Bestehorn, Michael}, title = {Numerical Results of 3D-Convection in a Binary Mixture for a Positive Separation Ratio}, language = {en} } @article{Bestehorn, author = {Bestehorn, Michael}, title = {Convection in thick and thin fluid layers with a free surface - The Influence of Evaporation}, language = {en} } @article{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {Phase field simulations for drops and bubbles}, language = {en} } @article{BorciaBorciaBestehorn, author = {Borcia, Rodica and Borcia, Ion-Dan and Bestehorn, Michael}, title = {Drops on an arbitrarily wetting substrate: A phase field description}, language = {en} } @article{BorciaBorciaBestehorn, author = {Borcia, Rodica and Borcia, Ion-Dan and Bestehorn, Michael}, title = {Liquid layers on a patterned surface}, series = {Soft Matter}, volume = {4}, journal = {Soft Matter}, number = {12}, pages = {2368 -- 2372}, language = {en} } @misc{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {Controlled Pattern Formation in Thin Liquid Layers}, language = {en} } @misc{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {A Phase Field Description of Spatio-Temporal Behavior in Thin Liquid Layers}, language = {en} } @article{BestehornHaken, author = {Bestehorn, Michael and Haken, H.}, title = {A Calculation of Transient Solutions Describing Roll and Hexagon Formation in the Convection Instability}, language = {en} } @article{BestehornHaken, author = {Bestehorn, Michael and Haken, H.}, title = {Transient Patterns of the Convection Instability: A Model Calculation}, language = {en} } @article{BestehornFriedrichHaken, author = {Bestehorn, Michael and Friedrich, R. and Haken, H.}, title = {The Oscillatory Instability of a Spatially Homogeneous State in Large Aspect Systems of Fluid Dynamics}, language = {en} } @article{BestehornFriedrichHaken, author = {Bestehorn, Michael and Friedrich, R. and Haken, H.}, title = {Two-dimensional Traveling Wave Patterns in Nonequilibrium Systems}, language = {en} } @article{BestehornFriedrichHaken, author = {Bestehorn, Michael and Friedrich, R. and Haken, H.}, title = {Traveling Waves in Nonequilibrium Systems}, language = {en} } @article{BestehornFriedrichHaken, author = {Bestehorn, Michael and Friedrich, R. and Haken, H.}, title = {Modulated Traveling Waves in Nonequilibrium Systems: The Blinking State}, language = {en} } @misc{PototskyArcherBestehornetal., author = {Pototsky, Andrey and Archer, Andrew J. and Bestehorn, Michael and Merkt, Domnic and Savelev, S. and Marchesoni, F.}, title = {Collective shuttling of attracting particles in asymmetric narrow channels}, language = {en} } @misc{BestehornTyvand, author = {Bestehorn, Michael and Tyvand, Peder A.}, title = {Merging and colliding bores}, language = {en} } @misc{TyvandBestehorn, author = {Tyvand, Peder A. and Bestehorn, Michael}, title = {Diffraction of Poincare waves by a change in ocean depth}, language = {en} } @article{FriedrichBestehornHaken, author = {Friedrich, R. and Bestehorn, Michael and Haken, H.}, title = {Pattern Formation in Convective Instabilities}, language = {en} } @article{BestehornHaken, author = {Bestehorn, Michael and Haken, H.}, title = {Traveling Waves and Pulses in a Two-Dimensional Large-Aspect-Ratio System}, series = {Physical Review A}, volume = {42}, journal = {Physical Review A}, number = {12}, issn = {0556-2791}, pages = {7195 -- 7203}, language = {en} } @article{BestehornHaken, author = {Bestehorn, Michael and Haken, H.}, title = {Associative Memory of a Dynamical System: The Example of the Convection Instability}, series = {Zeitschrift f{\"u}r Physik B}, volume = {82}, journal = {Zeitschrift f{\"u}r Physik B}, number = {2}, issn = {1431-584}, pages = {305 -- 308}, language = {en} } @article{BestehornPerezGarcia, author = {Bestehorn, Michael and P{\´e}rez-Garc{\´i}a, C.}, title = {Study of a Model of Thermal Convection in Cylindrical Containers}, language = {en} } @article{MillanRodriguezBestehornPerezGarciaetal., author = {Mill{\´a}n-Rodriguez, J. and Bestehorn, Michael and P{\´e}rez-Garc{\´i}a, C. and Neufeld, M. and Friedrich, R.}, title = {Motion of Defects in Rotating Fluids}, language = {en} } @article{BestehornNeufeldFriedrichetal., author = {Bestehorn, Michael and Neufeld, M. and Friedrich, R. and Haken, H.}, title = {Comment on Spiral pattern formation in Rayleigh-B{\´e}nard Convection}, language = {en} } @article{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {Phase-field model for Marangoni convection in liquid-gas systems with deformable interface}, language = {en} } @article{PototskyBestehornMerktetal., author = {Pototsky, Andrey and Bestehorn, Michael and Merkt, Domnic and Thiele, Uwe}, title = {Alternative pathways of dewetting for a thin two-layer film of soft matter}, doi = {10.48550/arXiv.nlin/0401042}, language = {en} } @article{MerktPototskyBestehornetal., author = {Merkt, Domnic and Pototsky, Andrey and Bestehorn, Michael and Thiele, Uwe}, title = {Long-wave theory of bounded two-layer films with a free liquid-liquid interface: Short and long-time evolution}, doi = {10.1063/1.1935487}, language = {en} } @article{PototskyBestehornMerktetal., author = {Pototsky, Andrey and Bestehorn, Michael and Merkt, Domnic and Thiele, Uwe}, title = {Evolution of interface patterns of three-dimensional two-layer liquid films}, series = {Europhysics Letters}, volume = {74}, journal = {Europhysics Letters}, number = {4}, issn = {0302-072X}, doi = {10.1209/epl/i2006-10026-8}, pages = {665 -- 671}, language = {en} } @article{BestehornMerkt, author = {Bestehorn, Michael and Merkt, Domnic}, title = {Regular surface patterns on Rayleigh-Taylor unstable evaporating films heated from below}, language = {en} } @article{BorciaBorciaBestehorn, author = {Borcia, Ion-Dan and Borcia, Rodica and Bestehorn, Michael}, title = {Long wave instabilities in binary mixture thin liquid films}, language = {en} } @article{BorciaBorciaBestehorn, author = {Borcia, Ion-Dan and Borcia, Rodica and Bestehorn, Michael}, title = {Soret effect in thin liquid films:Localized running drops, holes and stripes}, language = {en} } @misc{BestehornBorcia, author = {Bestehorn, Michael and Borcia, Ion-Dan}, title = {Thin film lubrication dynamics of a binarymixture}, language = {en} } @article{EnculescuBestehorn, author = {Enculescu, Mihaela and Bestehorn, Michael}, title = {Activity dynamics in non - localinteracting neural fields}, language = {en} } @article{HuttBestehornWennekers, author = {Hutt, A. and Bestehorn, Michael and Wennekers, T.}, title = {Pattern Formation in Intracortical Neuronal Fields}, language = {en} } @article{PenaPerezGarciaBestehorn, author = {Pena, B. and P{\´e}rez-Garc{\´i}a, C. and Bestehorn, Michael}, title = {Modulated standing waves resulting from a Hopf-wave interaction in a chemical model}, language = {en} } @article{EnculescuBestehorn, author = {Enculescu, Mihaela and Bestehorn, Michael}, title = {Liapunov functional for a delayedintegro-differential equation model of a neural field}, language = {en} } @article{PenaBestehorn, author = {Pena, B. and Bestehorn, Michael}, title = {Two-dimensional wave patterns near a Hopf-wave interaction in a chemical model}, language = {en} } @article{EnculescuBestehorn, author = {Enculescu, Mihaela and Bestehorn, Michael}, title = {Mechanisms for activity spread in a neural field model}, language = {en} } @misc{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {On the coalescence of sessile drops with miscible liquids}, series = {European Physical Journal E}, volume = {34}, journal = {European Physical Journal E}, number = {8}, issn = {1292-8941}, pages = {81}, language = {en} } @misc{BorciaMenzelBestehornetal., author = {Borcia, Rodica and Menzel, Stefan and Bestehorn, Michael and Karpitschka, Stefan and Riegler, Horst}, title = {Delayed coalescence of droplets with miscible liquids: Lubrication and phasefield theories}, series = {European Physical Journal E}, volume = {34}, journal = {European Physical Journal E}, number = {3}, issn = {1292-8941}, pages = {11024-9}, language = {en} } @misc{ReifVarlamovaVarlamovetal., author = {Reif, J{\"u}rgen and Varlamova, Olga and Varlamov, Sergej and Bestehorn, Michael}, title = {The role of asymmetric excitation in self-organized nanostructure formation upon femtosecond laser ablation}, series = {Applied Physics / A}, volume = {104}, journal = {Applied Physics / A}, number = {3}, issn = {1432-0630}, pages = {969 -- 973}, language = {en} } @misc{VarlamovaReifVarlamovetal., author = {Varlamova, Olga and Reif, J{\"u}rgen and Varlamov, Sergej and Bestehorn, Michael}, title = {The laser polarization as control parameter in the formation of laser-induced periodic surface structures: Comparison of numerical and experimental results}, series = {Applied Surface Science}, volume = {257}, journal = {Applied Surface Science}, number = {12}, issn = {0169-4332}, pages = {5465 -- 5469}, language = {en} } @misc{BorciaBestehorn, author = {Borcia, Rodica and Bestehorn, Michael}, title = {Numerical simulations on delayed coalescence of droplets in confinedgeometries}, language = {en} } @misc{BorciaBestehorn, author = {Borcia, Ion-Dan and Bestehorn, Michael}, title = {Simulation of pattern morphology in binary liquid mixtures}, language = {en} } @inproceedings{BorciaBestehornEgbers, author = {Borcia, Rodica and Bestehorn, Michael and Egbers, Christoph}, title = {Surface effects at the mixing of two perfectly miscible components in a thin liquid film}, series = {International Topical Team Workshop on Two-Phase Systems for Ground and Space Applications, ITTW 2013}, booktitle = {International Topical Team Workshop on Two-Phase Systems for Ground and Space Applications, ITTW 2013}, language = {en} } @inproceedings{BorciaBorciaBestehornetal., author = {Borcia, Ion-Dan and Borcia, Rodica and Bestehorn, Michael and Egbers, Christoph}, title = {Drops on cylindrical wires}, series = {International Topical Team Workshop on Two-Phase Systems for Ground and Space Applications, ITTW 2013}, booktitle = {International Topical Team Workshop on Two-Phase Systems for Ground and Space Applications, ITTW 2013}, language = {en} } @inproceedings{BorciaBorciaBestehornetal., author = {Borcia, Ion-Dan and Borcia, Rodica and Bestehorn, Michael and Borcia, C. and Dumitrascu, N. and Egbers, Christoph}, title = {Drops on cylindrical surfaces}, series = {7th Conference of the International Marangoni Association, Vienna (Austria), June 23-26, 2014}, booktitle = {7th Conference of the International Marangoni Association, Vienna (Austria), June 23-26, 2014}, publisher = {Techn. Univ.}, address = {Vienna}, pages = {S. 33}, language = {en} } @inproceedings{ReifVarlamovaVarlamovetal., author = {Reif, J{\"u}rgen and Varlamova, Olga and Varlamov, Sergej and Bestehorn, Michael}, title = {The role of asymmetric excitation in self-organized nanostructure formation upon femtosecondlaser ablation}, series = {International Symposium on High Power Laser Ablation 2012, Santa Fe, New Mexico, USA, 30 April - 3 May 2012}, booktitle = {International Symposium on High Power Laser Ablation 2012, Santa Fe, New Mexico, USA, 30 April - 3 May 2012}, editor = {Phipps, Claude R.}, publisher = {American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-1068-8}, pages = {428 -- 441}, language = {en} } @misc{VarlamovaReifVarlamovetal., author = {Varlamova, Olga and Reif, J{\"u}rgen and Varlamov, Sergej and Bestehorn, Michael}, title = {Modeling of the Laser Polarization as Control Parameter in Self-Organized Surface Pattern}, series = {Journal of Nanoscience and Nanotechnology}, volume = {11}, journal = {Journal of Nanoscience and Nanotechnology}, number = {10}, issn = {1533-4880}, pages = {9274 -- 9281}, language = {en} } @misc{VarlamovaCostacheReifetal., author = {Varlamova, Olga and Costache, Florenta Adriana and Reif, J{\"u}rgen and Bestehorn, Michael}, title = {Self-organized pattern formation upon femtosecond laser ablation by circular polarized light}, series = {Applied Surface Science}, volume = {252}, journal = {Applied Surface Science}, number = {13}, issn = {0169-4332}, pages = {4702 -- 4706}, language = {en} } @inproceedings{ReifCostacheEckertetal., author = {Reif, J{\"u}rgen and Costache, Florenta Adriana and Eckert, Sebastian and Kouteva-Arguirova, Simona and Bestehorn, Michael and Georgescu, Ionut and Semorek, A. F. and Martin, P. and Gobert, O. and Seifert, Winfried}, title = {Formation of self-organized regular nanostructures upon femtosecond laser ablation}, series = {Fifth International Symposium on Laser Precision Microfabrication, 11 - 14 May, 2004, Nara, Japan}, booktitle = {Fifth International Symposium on Laser Precision Microfabrication, 11 - 14 May, 2004, Nara, Japan}, publisher = {SPIE}, address = {Bellingham, Wash.}, isbn = {0-8194-5623-3}, pages = {S. 737}, language = {en} } @incollection{VarlamovaReifVarlamovetal., author = {Varlamova, Olga and Reif, J{\"u}rgen and Varlamov, Sergej and Bestehorn, Michael}, title = {Self-organized Surface Patterns Originatin from Laser-Induced Instability}, series = {Progress in nonlinear nano-optics}, booktitle = {Progress in nonlinear nano-optics}, editor = {Sakabe, Shuji and Lienau, Christoph and Grunwald, R{\"u}diger}, publisher = {Springer}, address = {Cham [u.a.]}, isbn = {978-3-319-12216-8}, pages = {3 -- 29}, language = {en} } @misc{ChengBestehornFiroozabadi, author = {Cheng, Philip and Bestehorn, Michael and Firoozabadi, Abbas}, title = {Effect of permeability anisotropy on density-driven flow for CO2 sequestration in saline aquifers}, series = {Water Resources Research}, volume = {48}, journal = {Water Resources Research}, number = {9}, issn = {1944-7973}, doi = {10.1029/2012WR011939}, pages = {W09539}, abstract = {Solubility trapping of carbon dioxide (CO2) in deep saline aquifers is considered one of the most effective methods for carbon sequestration. Dissolution of CO2 into the brine may create gravitational instabilities that lead to the onset of convection, which greatly enhances the storage efficiency and reduces the possibilities of leakage. Convection appears in the form of downward traveling fingers of relatively dense, CO2-dissolved fluid. Many natural aquifer formations display considerable permeability anisotropy, where the horizontal permeability kh may be several times greater than the vertical permeability kz. It has been previously found that increasing kh for a fixed kz reduces the critical time tc at which onset occurs and the critical wavelength λc with which the fingers initially form. We extend earlier work by showing how and why this occurs. Our results reveal new insights about λc. We have studied the behavior for times greater than tc using high-resolution numerical simulations. We show that the enhanced dissolution from convection can become significant much earlier in anisotropic media. Furthermore, the effects of anisotropy may be sustained for a long period of time. Our results suggest that permeability anisotropy can allow a wider range of aquifer formations to be considered for effective sequestration.}, language = {en} } @misc{BestehornFiroozabadi, author = {Bestehorn, Michael and Firoozabadi, Abbas}, title = {Effect of fluctuations on the onset of density-driven convection in porous media}, series = {Physics of Fluids}, volume = {24}, journal = {Physics of Fluids}, number = {11}, issn = {1089-7666}, doi = {10.1063/1.4767467}, pages = {114102}, abstract = {We study the dissolution of CO2 in saline aquifers. The long diffusion times can be accelerated by orders of magnitude from mass transfer that origins from convection.Convection occurs at a critical time via a phase transition from the horizontally homogeneous diffusion state. To start the instability, perturbations that break the horizontal translation symmetry are necessary. We start with the basic equations and the boundary conditions, examine the linearized equations around the diffusive time and z-dependent base state and compare different definitions of the critical time found in the literature. Taking a simple model we show the role of fluctuations for delayed instabilities if the control parameter is slowly swept through the bifurcation point. Apart from the critical time we use a "visible" time where convection is manifested in the vertical CO2 transport. We specify the perturbations with respect to their strength and length scale, and compute the critical times for various cases by numerical integration of the basic equations in two spatial dimensions. Fluctuating concentration at the upper boundary, fluctuating porosity as well fluctuating permeability are studied in detail. For the permeability fluctuation, the compressibility of the fluid becomes important and the velocity field cannot be derived from a stream function. Our work also includes non-isothermal conditions with a prescribed vertical geothermal gradient and space dependent thermal conductivity. Temperature fields for different standard configurations are computed numerically and serve as starting condition for density-driven convection. Based on our work, we conclude that the visible time is much larger than the critical time. The visible time is a strong function of strength and length scale of the perturbations.}, language = {en} } @misc{ReifVarlamovaUhligetal., author = {Reif, J{\"u}rgen and Varlamova, Olga and Uhlig, Sebastian and Varlamov, Sergej and Bestehorn, Michael}, title = {On the physics of self-organized nanostructure formation upon femtosecond laser ablation}, series = {Applied Physics A}, volume = {117}, journal = {Applied Physics A}, number = {1}, issn = {0947-8396}, doi = {10.1007/s00339-014-8339-x}, pages = {179 -- 184}, abstract = {We present new results on femtosecond LIPSS on silicon, fostering the dynamic model of self-organized structure formation. The first set of experiments demonstrates LIPSS formation by irradiation with a femtosecond white light continuum. The ripples are, as usual, perpendicular to the light polarization with a fluence-dependent wavelength between 500 and 700 nm. At higher dose (fluence × number of shots), the LIPSS turn to much coarser structures. The second set of experiments displays the dose dependence of pattern evolution at about threshold fluence. In contrast to the general case of multi-pulse LIPSS, where a strong dependence of the structures on the laser polarization is observed, single-shot exposition of silicon at about the ablation threshold results in a concentric pattern of very regular sub-wavelength ripples following the oval shape of the irradiated spot, without any reference to the laser polarization. When increasing the number of pulses, the usual, typical ripples develop and then coalesce into broader perpendicular structures, interlaced with remnants of the first, finer ripples.}, language = {en} } @misc{Bestehorn, author = {Bestehorn, Michael}, title = {Laterally Extended Thin Liquid Films with inertia Under External Vibrations}, series = {Physics of Fluids}, volume = {25}, journal = {Physics of Fluids}, number = {11}, issn = {1089-7666}, doi = {10.1063/1.4830255}, pages = {114106}, abstract = {We consider thin liquid films on a horizontal, solid, and completely wetting substrate. The substrate is subjected to oscillatory accelerations in the normal direction and/or in the horizontal direction. A linear Floquet analysis shows that the planar film surface loses stability if amplitudes and frequencies of the harmonic oscillations meet certain criteria. Based on the long wave lubrication approximation, we present an integral boundary layer model where the z component is integrated out and the spatial dimension is reduced by one. The linear stability analysis of this model shows good agreement with the exact problem and with the linearized long wave equations. Pattern formation in the nonlinear regime is computed numerically from the long wave model in two and three spatial dimensions. Normal oscillations show the traditional Faraday patterns such as squares and hexagons. Lateral oscillations cause a pattern formation scenario similar to spinodal dewetting, namely coarsening and no rupture. For certain amplitude and frequency ranges, combined lateral and normal oscillations can give rise to one or more traveling drops. Finally, we discuss the control of a drop's motion in the horizontal plane.}, language = {en} } @misc{BestehornHanOron, author = {Bestehorn, Michael and Han, Qi and Oron, Alexander}, title = {Nonlinear Pattern Formation in Thin Liqiud Films Under External Vibrations}, series = {Physical Review E}, volume = {88}, journal = {Physical Review E}, number = {2}, issn = {2470-0053}, doi = {10.1103/PhysRevE.88.023025}, pages = {023025}, abstract = {We study a thin liquid film with a free surface on a planar horizontal substrate. The substrate is subjected to oscillatory accelerations in the normal and/or in the horizontal direction(s). The description is based on the longwave approximation including inertia effects, which are important due to the large velocities imparted by external vibrations. The linearized system is examined using the Floquet analysis. Pattern formation in the nonlinear regime is computed numerically from the longwave equations for the thickness and the flow rate of the fluid in two and in three spatial dimensions. For certain amplitude and frequency ranges, combined lateral and normal oscillations can give rise to one or more traveling drops, similar to recent experimental findings by Brunet et al. [Phys. Rev. Lett. 99, 144501 (2007)].}, language = {en} } @misc{Bestehorn, author = {Bestehorn, Michael}, title = {Regular Hexagons and Stripes on Marangoni and Rayleigh-Taylor unstable volatile thin films}, series = {European Journal of Mechanics - B/Fluids}, volume = {47}, journal = {European Journal of Mechanics - B/Fluids}, doi = {10.1016/j.euromechflu.2013.12.005}, pages = {48 -- 56}, abstract = {Thin volatile Newtonian liquid films with a free surface on a cooled horizontal substrate are studied theoretically and numerically. We show that if the fluid is initially in equilibrium with its own vapor in the gas phase, regular surface deformation patterns in the form of long-wave hexagons or stripes having a well defined lateral length scale are observed, depending on the instability mechanism. This is different to the case without evaporation where rupture or coarsening to larger and larger spatially disordered patterns is seen in the long time limit. We propose to use such a system to create a regular structuring of the film's surface. Heat production by latent heat and the influence of a temperature dependent surface tension (Marangoni effect) are included as well. Special emphasis is laid on the so-called anomalous Marangoni effect. In this case a parameter region where stripes should occur already at threshold is found by means of a systematic weakly non-linear analysis.}, language = {en} }