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@article{faucris.109906764,
abstract = {We investigate the cooling rate of a gas of inelastically interacting particles. When we assume velocity-dependent coefficients of restitution the material cools down slower than with constant restitution. This behavior might have a large influence to clustering and structure formation processes.},
author = {Schwager, Thomas and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.57.650},
faupublication = {no},
journal = {Physical Review E},
pages = {650-654},
peerreviewed = {Yes},
title = {{Coefficient} of normal restitution of viscous particles and cooling rate of granular gases},
volume = {57},
year = {1998}
}
@article{faucris.122968604,
abstract = {Magnetresonanzaufnahmen zeigen, dass sich Tetraederwürfel dichter als andere konvexe Körper ungeordnet packen lassen.},
author = {Engel, Michael},
faupublication = {no},
journal = {Physik Journal},
pages = {18-19},
peerreviewed = {unknown},
title = {{Brennpunkt}: {Volle} {Packung}},
volume = {9},
year = {2010}
}
@article{faucris.122896004,
abstract = {The coefficient of restitution of colliding viscoelastic spheres is known analytically as a complete series expansion in terms of the impact velocity where all (infinitely many) coefficients are known. While being analytically exact, this result is not suitable for applications in efficient event-driven molecular dynamics (eMD) or direct simulation Monte Carlo (DSMC) methods. Based on the analytic result, here we derive expressions for the coefficient of restitution that allow for application in efficient eMD and DSMC simulations of granular systems. © 2011 American Physical Society.},
author = {Müller, Patric and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.84.021302},
faupublication = {yes},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Collision} of viscoelastic spheres: {Compact} expressions for the coefficient of normal restitution},
volume = {84},
year = {2011}
}
@article{faucris.122096304,
abstract = {We measure the two-point correlation of free Voronoi volumes in binary disc packings, where the packing fraction phi(avg) ranges from 0.8175 to 0.8380. We observe short-ranged correlations over the whole range of phi(avg) and anticorrelations for phi(avg) > 0.8277. The spatial extent of the anticorrelation increases with phi(avg) while the position of the maximum of the anticorrelation and the extent of the positive correlation shrink with phi(avg). We conjecture that the onset of anticorrelation corresponds to dilatancy onset in this system. Copyright (C) EPLA, 2012},
author = {Schröter, Matthias and Zhao, Song-Chuan and Sidle, Stacy and Swinney, Harry L.},
doi = {10.1209/0295-5075/97/34004},
faupublication = {no},
journal = {EPL - Europhysics Letters},
peerreviewed = {Yes},
title = {{Correlation} between {Voronoi} volumes in disc packings},
volume = {97},
year = {2012}
}
@article{faucris.213287957,
abstract = {We argue that the alignment of Lyapunov vectors provides a quantitative criterion to predict catastrophes, i.e. the imminence of large-amplitude events in chaotic time-series of observables generated by sets of ordinary differential equations. Explicit predictions are reported for a Rössler oscillator and for a semiconductor laser with optoelectronic feedback.},
author = {Beims, Marcus W. and Gallas, Jason},
doi = {10.1038/srep37102},
faupublication = {yes},
journal = {Scientific Reports},
note = {EAM Import::2019-03-13},
peerreviewed = {Yes},
title = {{Alignment} of {Lyapunov} {Vectors}: {A} {Quantitative} {Criterion} to {Predict} {Catastrophes}?},
volume = {6},
year = {2016}
}
@article{faucris.122894684,
abstract = {The coefficient of normal restitution of colliding viscoelastic spheres is computed as a function of the material properties and the impact velocity. From simple arguments it becomes clear that, in a collision of purely repulsively interacting particles, the particles lose contact slightly before the distance of the centers of the spheres reaches the sum of the radii, that is, the particles recover their shape only after they lose contact with their collision partner. This effect was neglected in earlier calculations, which leads erroneously to attractive forces and thus to an underestimation of the coefficient of restitution. As a result we find a different dependence of the coefficient of restitution on the impact rate. © 2008 The American Physical Society.},
author = {Schwager, Thomas and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.78.051304},
faupublication = {no},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Coefficient} of restitution for viscoelastic spheres: {The} effect of delayed recovery},
volume = {78},
year = {2008}
}
@book{faucris.113993044,
abstract = {This chapter contains sections titled: Introduction Forces Between Granular Particles Elastic Forces Viscous Forces Adhesion of Contacting Particles Collision of Granular Particles Coefficient of Restitution Dimensional Analysis Coefficient of Restitution for Spheres Coefficient of Restitution for Adhesive Collisions Conclusion References.},
author = {Pöschel, Thorsten and Brilliantov, Nikolai},
doi = {10.1002/352760362X.ch8},
faupublication = {yes},
isbn = {9783527403738},
keywords = {Collision of adhesive viscoelastic particles; Collision of granular particles; Dense granular flow; Forces between granula particles; Physics of granular media},
pages = {189-209},
peerreviewed = {Yes},
publisher = {wiley},
title = {{Collision} of {Adhesive} {Viscoelastic} {Particles}},
year = {2005}
}
@article{faucris.121335764,
abstract = {Computersimulationen und Experimente mit Schaumblasen zeigen, wie man Kugeln nicht nur dicht stapelt, sondern auch mechanisch stabil.},
author = {Engel, Michael},
faupublication = {no},
journal = {Physik Journal},
pages = {24-25},
peerreviewed = {unknown},
title = {{Brennpunkt}: {Aus} {Schaum} gebaut},
volume = {11},
year = {2012}
}
@article{faucris.122087284,
abstract = {We have discovered an invariant distribution for local packing configurations in static granular media. This distribution holds in experiments for packing fractions covering most of the range from random loose packed to random close packed, for bead packs prepared both in air and in water. Assuming only that there exist elementary cells in which the system volume is subdivided, we derive from statistical mechanics a distribution that is in accord with the observations. This universal distribution function for granular media is analogous to the Maxwell-Boltzmann distribution for molecular gasses.},
author = {Schröter, Matthias and Aste, T. and Di Matteo, Tiziana and Saadatfar, Mohammad and Senden, T.J. and Swinney, Harry L.},
doi = {10.1209/0295-5075/79/24003},
faupublication = {no},
journal = {EPL - Europhysics Letters},
month = {Jan},
peerreviewed = {Yes},
title = {{An} invariant distribution in static granular media},
volume = {79},
year = {2007}
}
@incollection{faucris.109107724,
address = {New York},
author = {Ribeiro Parteli, Eric Josef},
booktitle = {Encyclopedia of Planetary Landforms},
editor = {Hargitai, H., Kereszturi, Ákos},
faupublication = {yes},
pages = {1-3},
peerreviewed = {unknown},
publisher = {Springer},
title = {{Dome} {Dune}},
year = {2014}
}
@article{faucris.107033124,
abstract = {
Grid based fluid simulation methods are not able to solve complex non-linear dynamics like the rupture of a dynamic liquid bridge between freely colliding solids–an exemplary scenario of capillary forces competing with inertial forces in engineering applications–using a monolithic formulation for the solid and liquid phases present. We introduce a new Incompressible Smoothed Particle Hydrodynamics method for simulating three dimensional fluid-solid interaction flows with capillary (wetting and surface tension) effects at free surfaces. This meshless approach presents significant advantages over grid based approaches in terms of being monolithic and in handling interaction with free solids. The method is validated for accuracy and stability in dynamic scenarios involving surface tension and wetting. We then present three dimensional simulations of crown forming instability following the splash of a liquid drop, and the rupture of a liquid bridge between two colliding solid spheres, to show the method’s advantages in the study of dynamic micromechanical phenomena involving capillary flows.

},
author = {Nair, Prapanch and Pöschel, Thorsten},
doi = {10.1016/j.ces.2017.10.042},
faupublication = {yes},
journal = {Chemical Engineering Science},
pages = {192-204},
peerreviewed = {Yes},
title = {{Dynamic} capillary phenomena using {Incompressible} {SPH}},
volume = {176},
year = {2017}
}
@article{faucris.122384504,
abstract = {We report a degenerate quasicrystal in Monte Carlo simulations of hard triangular bipyramids each composed of two regular tetrahedra sharing a single face. The dodecagonal quasicrystal is similar to that recently reported for hard tetrahedra [Haji-Akbari et al., Nature (London) 462, 773 (2009)] but degenerate in the pairing of tetrahedra, and self-assembles at packing fractions above 54%. This notion of degeneracy differs from the degeneracy of a quasiperiodic random tiling arising through phason flips. Free energy calculations show that a triclinic crystal is preferred at high packing fractions.},
author = {Engel, Michael and Haji-Akbari, Amir and Glotzer, Sharon C.},
doi = {10.1103/PhysRevLett.107.215702},
faupublication = {no},
journal = {Physical Review Letters},
peerreviewed = {Yes},
title = {{Degenerate} {Quasicrystal} of {Hard} {Triangular} {Bipyramids}},
volume = {107},
year = {2011}
}
@article{faucris.107138064,
abstract = {Ratchets are simple mechanical devices which combine spatial asymmetry and nonequilibrium to produce counterintuitive transport of particles. The operation and properties of *linear* ratchets have already been extensively explored. However, very little is known about *circular granular* ratchets, startling devices able to convert vertical vibrations into rotations of the device. Here, we report results of systematic numerical investigations of the operational characteristics of circular granular ratchets. Several distinct behaviors are identified and explained in terms of the inner flow fields of the ratchet. All dynamical regimes found are robust and should not be difficult to observe in laboratory experiments.},
author = {Müller, Patric and Gallas, Jason and Pöschel, Thorsten},
doi = {10.1038/s41598-017-12588-w},
faupublication = {yes},
journal = {Scientific Reports},
peerreviewed = {Yes},
title = {{Dynamical} regimes and stability of circular granular ratchets},
volume = {7},
year = {2017}
}
@article{faucris.114387504,
abstract = {We discuss several models for granular particles commonly used in Molecular Dynamics simulations of granular materials, including spheres with linear dashpot force, viscoelastic spheres and adhesive viscoelastic spheres. Starting from the vectorial interaction forces we derive the coefficients of normal and tangential restitution as functions of the vectorial impact velocity and of the material constants. We review the methods of measurements of the coefficients of restitution and characterize the coefficient of normal restitution as a fluctuating quantity. Moreover, the scaling behavior and the influence of different force laws on the dynamical system behavior are discussed. The powerful method of event-driven Molecular Dynamics is described and the algorithmic simulation technique is explained in detail. Finally we discuss the limitations of event-driven MD.},
author = {Pöschel, Thorsten and Brilliantov, Nikolai and Formella, Arno and Heckel, Michael and Kruelle, Christof and Müller, Patric and Salueña, Clara and Schwager, Thomas},
doi = {10.3166/ejece.12.827-870},
faupublication = {yes},
journal = {European Journal of Environmental and Civil Engineering},
pages = {827--870},
peerreviewed = {Yes},
title = {{Contact} of granular particles and the simulation of rapid flows using event-driven molecular dynamics},
volume = {12},
year = {2008}
}
@article{faucris.106912564,
abstract = {Large-scale computer simulations are presented to investigate the avalanche statistics of sandpiles using molecular dynamics. We show that different methods of measurement lead to contradictory conclusions, presumably due to avalanches not reaching the end of the experimental table.},
author = {Buchholtz, Volkhard and Pöschel, Thorsten},
doi = {10.1007/BF02174136},
faupublication = {no},
journal = {Journal of Statistical Physics},
keywords = {Granular material; Self-organized criticality},
pages = {1373-1378},
peerreviewed = {Yes},
title = {{Avalanche} statistics of sand heaps},
volume = {84},
year = {1996}
}
@article{faucris.109888944,
abstract = {We discuss a new optimization strategy, which considerably improves the effectivity of evolutionary algorithms applied to a certain class of optimization problems. The basic principle is to solve first a simpler related problem, which is constructed by introducing additional degrees of freedom to the landscape. Starting from the solution in this simplified landscape we remove stepwise the added degrees of freedom. Our optimization strategy is demonstrated for a sample problem.},
author = {Buchholtz, Volkhard and Pöschel, Thorsten},
doi = {10.1142/S0218127497000546},
faupublication = {no},
journal = {International Journal of Bifurcation and Chaos},
pages = {751-757},
peerreviewed = {Yes},
title = {{Adaptive} evolutionary optimization of team work},
volume = {7},
year = {1997}
}
@inproceedings{faucris.106421524,
author = {Engel, Michael},
booktitle = {Mini Stat Mech Meeting},
date = {2014-01-10/2014-01-12},
faupublication = {no},
peerreviewed = {unknown},
title = {{Beyond} close packing: complex order with simple models},
venue = {Berkeley, California},
year = {2014}
}
@article{faucris.115463744,
abstract = {We report a five-component autonomous chaotic oscillator

of jerky type, hitherto the simplest of its kind, using only

one operational amplifier. The key component of the circuit is a

junction field-effect transistor operating in its triode region, which

provides a nonlinear resistor of antisymmetrical current–voltage

characteristic, emulating a Colpitts-like chaotic circuit. We describe

the experimental results illustrating the dynamical behavior

of the circuit. In addition, we report numerical simulations of

a model of the circuit which display good agreement with our

measurements.},
author = {Tchitnga, Robert and Nguazon, Tekou and Louodop Fotso,, Patrick H. and Gallas, Jason},
faupublication = {yes},
journal = {IEEE Transactions on Circuits and Systems Ii-Express Briefs},
keywords = {Bifurcations, jerk oscillator, junction field-effect transistor (JFET), piecewise (PW) nonlinearity (NLT), simplest chaotic circuit I},
peerreviewed = {Yes},
title = {{Chaos} in a {Single} {Op}-{Amp}–{Based} {Jerk} {Circuit}: {Experiments} and {Simulations}},
volume = {Vol. 63},
year = {2016}
}
@article{faucris.123382644,
abstract = {We study the packing of fine glass powders of mean particle diameter in the range (4-52)μm both experimentally and by numerical DEM simulations. We obtain quantitative agreement between the experimental and numerical results, if both types of attractive forces of particle interaction, adhesion and non-bonded van der Waals forces are taken into account. Our results suggest that considering only viscoelastic and adhesive forces in DEM simulations may lead to incorrect numerical predictions of the behavior of fine powders. Based on the results from simulations and experiments, we propose a mathematical expression to estimate the packing fraction of fine polydisperse powders as a function of the average particle size.},
author = {Ribeiro Parteli, Eric Josef and Schmidt, Jochen and Blümel, Christina and Wirth, Karl-Ernst and Peukert, Wolfgang and Pöschel, Thorsten},
doi = {10.1038/srep06227},
faupublication = {yes},
journal = {Scientific Reports},
peerreviewed = {Yes},
title = {{Attractive} particle interaction forces and packing density of fine glass powders},
volume = {4},
year = {2014}
}
@article{faucris.109912924,
abstract = {We investigate the collision of adhesive viscoelastic spheres in quasistatic approximation where the adhesive interaction is described by the Johnson, Kendall, and Roberts (JKR) theory. The collision dynamics, based on the dynamic contact force, describes both restitutive collisions quantified by the coefficient of restitution ε as well as aggregative collisions, characterized by the critical aggregative impact velocity gcr. Both quantities ε and gcr depend sensitively on the impact velocity and particle size. Our results agree well with laboratory experiments. © 2007 The American Physical Society.},
author = {Brilliantov, Nikolai V. and Albers, Nicole and Spahn, Frank and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.76.051302},
faupublication = {no},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Collision} dynamics of granular particles with adhesion},
volume = {76},
year = {2007}
}
@article{faucris.109900384,
abstract = {The detailed mechanism of the formation of net and branching leaf structures is not known yet. Several mathematical modelling attempts to generate those structures have been made previously, based on biochemical or purely mathematical assumptions. Here, we present a simple model, based on plausible biophysical suppositions, which is able to reproduce the formation of a ramified structure grown out of a single activated cell. © 1994.},
author = {Pöschel, Thorsten and Malchow, H.},
doi = {10.1016/0960-0779(94)90004-3},
faupublication = {no},
journal = {Chaos Solitons & Fractals},
pages = {1883-1888},
peerreviewed = {Yes},
title = {{A} simple model for the growth of ramified leaf structures},
volume = {4},
year = {1994}
}
@article{faucris.217790523,
abstract = {Pt catalysts are widely studied for the oxygen reduction reaction, but their cost and susceptibility to poisoning limit their use. A strategy to address both problems is to incorporate a second transition metal to form a bimetallic alloy; however, the durability of such catalysts can be hampered by leaching of non-noble metal components. Here, we show that random alloyed surfaces can be stabilized to achieve high durability by depositing the alloyed phase on top of intermetallic seeds using a model system with PdCu cores and PtCu shells. Specifically, random alloyed PtCu shells were deposited on PdCu seeds that were either the atomically random face-centered cubic phase (FCC A1, Fm3m) or the atomically ordered CsCl-like phase (B2, Pm3m). Precise control over crystallite size, particle shape, and composition allowed for comparison of these two core@shell PdCu@PtCu catalysts and the effects of the core phase on electrocatalytic durability. Indeed, the nanocatalyst with the intermetallic core saw only an 18% decrease in activity after stability testing (and minimal Cu leaching), whereas the nanocatalyst with the random alloy core saw a 58% decrease (and greater Cu leaching). The origin of this enhanced durability was probed by classical molecular dynamics simulations of model catalysts, with good agreement between model and experiment. Although many random alloy and intermetallic nanocatalysts have been evaluated, this study directly compares random alloy and intermetallic cores for electrocatalysis with the enhanced durability achieved with the intermetallic cores likely general to other core@shell nanocatalysts.},
author = {Gamler, Jocelyn T.L. and Leonardi, Alberto and Ashberry, Hannah M. and Daanen, Nicholas N. and Losovyj, Yaroslav and Unocic, Raymond R. and Engel, Michael and Skrabalak, Sara E.},
doi = {10.1021/acsnano.8b08007},
faupublication = {yes},
journal = {ACS nano},
keywords = {electrocatalysts; multimetallic; nanocatalysts; nanoparticles; platinum alloys},
note = {CRIS-Team Scopus Importer:2019-05-17},
pages = {4008-4017},
peerreviewed = {Yes},
title = {{Achieving} {Highly} {Durable} {Random} {Alloy} {Nanocatalysts} through {Intermetallic} {Cores}},
volume = {13},
year = {2019}
}
@article{faucris.119273704,
abstract = {The transport of sediment by a fluid along the surface is responsible for dune formation, dust entrainment, and a rich diversity of patterns on the bottom of oceans, rivers, and planetary surfaces. Most previous models of sediment transport have focused on the equilibrium (or saturated) particle flux. However, the morphodynamics of sediment landscapes emerging due to surface transport of sediment is controlled by situations out of equilibrium. In particular, it is controlled by the saturation length characterizing the distance it takes for the particle flux to reach a new equilibrium after a change in flow conditions. The saturation of mass density of particles entrained into transport and the relaxation of particle and fluid velocities constitute the main relevant relaxation mechanisms leading to saturation of the sediment flux. Here we present a theoretical model for sediment transport which, for the first time, accounts for both these relaxation mechanisms and for the different types of sediment entrainment prevailing under different environmental conditions. Our analytical treatment allows us to derive a closed expression for the saturation length of sediment flux, which is general and thus can be applied under different physical conditions.},
author = {Ribeiro Parteli, Eric Josef and Herrmann, Hans J. and Kok, Jasper F. and Päthz, Thomas},
doi = {10.1103/PhysRevE.89.052213},
faupublication = {yes},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Analytical} model for flux saturation in sediment transport},
volume = {89},
year = {2014}
}
@article{faucris.119186804,
abstract = {With the assumption of a linear-dashpot interaction force, the coefficient of restitution, ε (k, γ), can be computed as a function of the elastic and dissipative material constants, k and γ by integrating Newton's equation of motion for an isolated pair of colliding particles. If we require further that the particles interact exclusively repulsive, which is a common assumption in granular systems, we obtain an expression ε (k, γ) which differs even qualitatively from the known result ε (k, γ). The expression ε (k, γ) allows to relate Molecular Dynamics simulations to event-driven Molecular Dynamics for a widely used collision model. © 2007 Springer-Verlag.},
author = {Schwager, Thomas and Pöschel, Thorsten},
doi = {10.1007/s10035-007-0065-z},
faupublication = {no},
journal = {Granular Matter},
keywords = {Coefficient of restitution; Particle collisions},
pages = {465-469},
peerreviewed = {Yes},
title = {{Coefficient} of restitution and linear-dashpot model revisited},
volume = {9},
year = {2007}
}
@misc{faucris.111217964,
author = {Michelsen, Britt},
faupublication = {yes},
peerreviewed = {automatic},
title = {{Validation} of {Dune} {Simulations} using {OpenFOAM}},
year = {2012}
}
@article{faucris.213304818,
abstract = {Starting from three-dimensional volume data of a granular packing, as, e.g., obtained by X-ray Computed Tomography, we discuss methods to first detect the individual particles in the sample and then analyze their properties. This analysis includes the pair correlation function, the volume and shape of the Voronoi cells, and the number and type of contacts formed between individual particles. We mainly focus on packings of monodisperse spheres, but we will also comment on other monoschematic particles such as ellipsoids and tetrahedra. This paper is accompanied by a package of free software containing all programs (including source code) and an example three-dimensional dataset which allows the reader to reproduce and modify all examples given.},
author = {Weis, Simon and Schröter, Matthias},
doi = {10.1063/1.4983051},
faupublication = {yes},
journal = {Review of Scientific Instruments},
note = {EAM Import::2019-03-13},
peerreviewed = {Yes},
title = {{Analyzing} {X}-ray tomographies of granular packings},
volume = {88},
year = {2017}
}
@article{faucris.122887864,
abstract = {A two-dimensional cellular automaton is introduced to model the flow and jamming of vehicular traffic in cities. Each site of the automaton represents a crossing where a finite number of cars can wait approaching the crossing from each of the four directions. The flow of cars obeys realistic traffic rules. We investigate the dependence of the average velocity of cars on the global traffic density. At a critical threshold for the density the average velocity reduces drastically caused by jamming. For the low-density regime we provide analytical results which agree with the numerical results. © 1995.},
author = {Freund, Jan A. and Pöschel, Thorsten},
doi = {10.1016/0378-4371(95)00170-C},
faupublication = {no},
journal = {Physica A-Statistical Mechanics and Its Applications},
pages = {95-113},
peerreviewed = {Yes},
title = {{A} statistical approach to vehicular traffic},
volume = {219},
year = {1995}
}
@article{faucris.109901704,
abstract = {Granular ratchets are well-known devices that when driven vertically produce a counterintuitive horizontal transport of particles. Here we report the experimental observation of a complementary effect: the striking ability of circular ratchets to convert their vertical vibration into their own rotation. The average revolution speed shows a maximum value for an optimal tooth height. With no special effort the rotation speed could be maintained steady during several hours. Unexpected random arrests and reversals of the velocity were also observed abundantly. © 2012 American Physical Society.},
author = {Heckel, Michael and Müller, Patric and Pöschel, Thorsten and Gallas, Jason},
doi = {10.1103/PhysRevE.86.061310},
faupublication = {yes},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Circular} ratchets as transducers of vertical vibrations into rotations},
volume = {86},
year = {2012}
}
@article{faucris.109909184,
abstract = {We perform a dimension analysis for colliding viscoelastic spheres to show that the coefficient of normal restitution ε depends on the impact velocity g as ε=1-γg+γg+ ⋯, in accordance with recent findings. We develop a simple theory to find explicit expressions for coefficients γ and γ. Using these and few next expansion coefficients for ε(g) we construct a Padé approximation for this function which may be used for a wide range of impact velocities where the concept of the viscoelastic collision is valid. The obtained expression reproduces quite accurately the existing experimental dependence ε(g) for ice particles.},
author = {Ramirez, Rosa and Pöschel, Thorsten and Brilliantov, Nikolai and Schwager, Thomas},
doi = {10.1103/PhysRevE.60.4465},
faupublication = {no},
journal = {Physical Review E},
pages = {4465-4472},
peerreviewed = {Yes},
title = {{Coefficient} of restitution of colliding viscoelastic spheres},
volume = {60},
year = {1999}
}
@article{faucris.117458924,
abstract = {We study experimentally the dissipation of energy in a rotating cylinder which is partially filled by granular material. We consider the range of angular velocity corresponding to continous and stationary flow of the granulate. In this regime, the stationary state depends on the angular velocity and on the filling mass. For a wide interval of filling levels we find a universal behavior of the driving torque required to sustain the stationary state as a function of the angular velocity. The result may be of relevance to industrial applications, e.g. to understand the power consumption of ball mills or rotary kilns and also for damping applications where mechanical energy has to be dissipated in a controlled wa},
author = {Sack, Achim and Pöschel, Thorsten},
doi = {10.1038/srep26833},
faupublication = {yes},
journal = {Scientific Reports},
peerreviewed = {Yes},
title = {{Dissipation} of {Energy} by {Dry} {Granular} {Matter} in a {Rotating} {Cylinder}},
volume = {6},
year = {2016}
}
@article{faucris.122587124,
abstract = {In a granular gas of rough particles the spin of a grain is correlated with its linear velocity. We develop an analytical theory to account for these correlations and compare its predictions to numerical simulations, using Direct Simulation Monte Carlo as well as Molecular Dynamics. The system is shown to relax from an arbitrary initial state to a steady-state, which is characterized by time-independent, finite correlations of spin and linear velocity. The latter are analyzed systematically for a wide range of system parameters, including the coefficients of tangential and normal restitution as well as the moment of inertia of the particles. For most parameter values the axis of rotation and the direction of linear momentum are perpendicular like in a sliced tennis ball, while parallel orientation, like in a rifled bullet, occurs only for a small range of parameters. The limit of smooth spheres is singular: any arbitrarily small roughness unavoidably causes significant translation-rotation correlations, whereas for perfectly smooth spheres the rotational degrees of freedom are completely decoupled from the dynamic evolution of the gas. © 2009 EDP Sciences and Springer.},
author = {Kranz, W. T. and Brilliantov, Nikolai V. and Pöschel, Thorsten and Zippelius, A.},
doi = {10.1140/epjst/e2010-01196-0},
faupublication = {yes},
journal = {European Physical Journal-Special Topics},
pages = {91-111},
peerreviewed = {Yes},
title = {{Correlation} of spin and velocity in the homogeneous cooling state of a granular gas of rough particles},
volume = {179},
year = {2009}
}
@inproceedings{faucris.120383164,
author = {Engel, Michael},
booktitle = {Mathematics of Distances and Applications},
date = {2012-07-02/2012-07-05},
faupublication = {no},
peerreviewed = {unknown},
title = {{Aperiodic} order in self-assembly with anisotopic particles and competing distances},
venue = {Varna},
year = {2012}
}
@inproceedings{faucris.122137884,
abstract = {We investigate the collective dissipative behavior of a model granular material (steel beads) when subjected to vibration. To this end, we study the attenuation of the amplitude of an oscillating leaf spring whose free end carries a rectangular box partly filled with granulate. To eliminate the perturbing influence of gravity, the experiment was performed under conditions of microgravity during parabolic flights. Different regimes of excitation could be distinguished, namely, a gas-like state of disordered particle motion and a state where the particles slosh back and forth between the container walls in a collective way, referred to as collect-and-collide regime. For the latter regime, we provide an expression for the container size leading to maximal dissipation of energy, that also marks the transition to the gas like regime. Also for systems driven at fixed amplitude and frequency, we find both the gas regime and the collect-and-collide regime resulting in similar dissipative behavior as in the case of the attenuating vibration. © 2013 AIP Publishing LL},
author = {Kollmer, Jonathan and Sack, Achim and Heckel, Michael and Zimber, Fabian and Müller, Patric and Bannerman, Marcus and Pöschel, Thorsten},
booktitle = {7th International Conference on Micromechanics of Granular Media: Powders and Grains 2013},
doi = {10.1063/1.4812055},
faupublication = {yes},
isbn = {9780735411661},
keywords = {damping; Granular material},
pages = {811-814},
peerreviewed = {Yes},
title = {{Collective} granular dynamics in a shaken container at low gravity conditions},
venue = {Sydney, NSW},
volume = {1542},
year = {2013}
}
@article{faucris.123019644,
abstract = {By means of experiments in microgravity conditions, we show that granular systems subjected to sinusoidal vibrations respond either by harmonic or gaslike dynamics, depending on the parameters of the vibration, amplitude and frequency, and the container size, while subharmonic response is unstable, except for extreme material properties and particular initial conditions. The absence of subharmonic response in vibrated granular systems implies that granular dampeners cannot reveal higher-order resonances, which makes them even more attractive for technical applications. Extensive molecular dynamics simulations support our findings.},
author = {Kollmer, Jonathan and Tupy, Martin and Heckel, Michael and Sack, Achim and Pöschel, Thorsten},
doi = {10.1103/PhysRevApplied.3.024007},
faupublication = {yes},
journal = {Physical Review Applied},
peerreviewed = {Yes},
title = {{Absence} of subharmonic response in vibrated granular systems under microgravity conditions},
url = {http://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84951752550&origin=inward},
volume = {3},
year = {2015}
}
@incollection{faucris.218986315,
abstract = {In this chapter, we will introduce useful tools of Quantum Statistics. Most of them will be used in later chapters of this book to solve concrete problems. Our survey covers, of course, the most prominent methods such as density operators introduced by von Neumann and Landau, Wigner’s phase-space functions method, and Bogolyubov’s method of reduced density operators. Matsubara’s thermodynamical Green’s functions and real-time Green’s functions are important methods in the field of quantum plasmas but are discussed here only rather briefly.},
author = {Ebeling, Werner and Pöschel, Thorsten},
booktitle = {Lectures on Quantum Statistics},
doi = {10.1007/978-3-030-05734-3_4},
faupublication = {yes},
isbn = {978-3-030-05734-3},
note = {CRIS-Team Scopus Importer:2019-05-28},
pages = {91-140},
peerreviewed = {unknown},
publisher = {Springer Verlag},
series = {Lecture Notes in Physics},
title = {{Density} operators and other tools of quantum statistics},
volume = {953},
year = {2019}
}
@article{faucris.122017104,
abstract = {A computer aided method using symbolic computations that enables the calculation of the source terms (Boltzmann) in Grad’s method of moments is presented. The method is extremely powerful, easy to program and allows the derivation of balance equations to very high moments (limited only by computer resources). For sake of demonstration the method is applied to a simple case: the one-dimensional stationary granular gas under gravity. The method should find applications in the field of rarefied gases, as well. Questions of convergence, closure are beyond the scope of this article.},
author = {Serero, Dan and Noskowicz, S. H.},
faupublication = {yes},
journal = {Mathematical Modelling of Natural Phenomena},
pages = {151 - 174},
peerreviewed = {Yes},
title = {{Application} of the {Method} of {Generating} {Functions} to the {Derivation} of {Grad}’s {N}-{Moment} {Equations} for a {Granular} {Gas}},
volume = {6},
year = {2011}
}
@article{faucris.109920844,
abstract = {Assume in a sample of size M one finds M representatives of species i with i = 1 ⋯ N*. The normalized frequency p* ≡ M/M, based on the finite sample, may deviate considerably from the true probabilities p. We propose a method to infer rank-ordered true probabilities r from measured frequencies M. We show that the rank-ordered probabilities provide important informations on the system, e.g., the true number of species, the Shannon- and the Renyi-entropies. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2004.},
author = {Pöschel, Thorsten and Ebeling, Werner and Frömmel, Cornelius and Ramirez, Rosa},
doi = {10.1140/epje/e2004-00025-4},
faupublication = {no},
journal = {European Physical Journal E},
pages = {531-541},
peerreviewed = {Yes},
title = {{Correction} algorithm for finite sample statistics},
volume = {12},
year = {2003}
}
@article{faucris.213298491,
abstract = {Disordered dielectric materials with structural correlations show unconventional optical behavior: They can be transparent to long-wavelength radiation, while at the same time have isotropic band gaps in another frequency range. This phenomenon raises fundamental questions concerning photon transport through disordered media. While optical transparency in these materials is robust against recurrent multiple scattering, little is known about other transport regimes like diffusive multiple scattering or Anderson localization. Here, we investigate band gaps, and we report Anderson localization in 2D disordered dielectric structures using numerical simulations of the density of states and optical transport statistics. The disordered structures are designed with different levels of positional correlation encoded by the degree of stealthiness \textgreekq. To establish a unified view, we propose a correlation-frequency (\textgreekq--\textgreekn) transport phase diagram. Our results show that, depending only on \textgreekq, a dielectric material can transition from localization behavior to a band gap crossing an intermediate regime dominated by tunneling between weakly coupled states.},
author = {Froufe-Perez, Luis S. and Engel, Michael and Jose Saenz, Juan and Scheffold, Frank},
doi = {10.1073/pnas.1705130114},
faupublication = {yes},
journal = {Proceedings of the National Academy of Sciences},
note = {EAM Import::2019-03-13},
pages = {9570-9574},
peerreviewed = {Yes},
title = {{Band} gap formation and {Anderson} localization in disordered photonic materials with structural correlations},
volume = {114},
year = {2017}
}
@article{faucris.109917764,
abstract = {In horizontally shaken granular material different types of pattern formation have been reported. We want to deal with the convection instability which has been observed in experiments and which recently has been investigated numerically. Using two dimensional molecular dynamics we show that the convection pattern depends crucially on the inelastic properties of the material. The concept of restitution coefficient provides arguments for the change of the behaviour with varying inelasticity.},
author = {Salueña, Clara and Pöschel, Thorsten},
doi = {10.1007/s101890050006},
faupublication = {no},
journal = {European Physical Journal E},
pages = {55-59},
peerreviewed = {Yes},
title = {{Convection} in horizontally shaken granular material},
volume = {1},
year = {2000}
}
@article{faucris.109106844,
abstract = {This paper reports a detailed numerical investigation of the geometrical and structural properties of three-dimensional heaps of particles. Our goal is the characterization of very large heaps produced by ballistic deposition from extended circular dropping areas. First, we provide an in-depth study of the formation of monodisperse heaps of particles. We find very large heaps to contain three new geometrical characteristics: they may display two external angles of repose, one internal angle of repose, and four distinct packing fraction (density) regions. Such features are found to be directly connected with the size of the dropping zone. We derive a differential equation describing the boundary of an unexpected triangular packing fraction zone formed under the dropping area.We investigate the impact that noise during the deposition has on the final heap structure. In addition, we perform two complementary experiments designed to test the robustness of the novel features found. The first experiment considers changes due to polydispersity. The second checks what happens when letting the extended dropping zone to become a point-like source of particles, the more common type of source.},
author = {Gallas, Jason and Pöschel, Thorsten and Topic, Nikola},
doi = {10.1080/14786435.2013.797618},
faupublication = {yes},
journal = {Philosophical Magazine},
pages = {4090-4107},
peerreviewed = {unknown},
title = {{Characteristics} of large threedimensional heaps of particles produced by ballistic deposition from extended sources},
volume = {93},
year = {2013}
}
@article{faucris.119401524,
abstract = {
Besides its importance for science and engineering, the process of drop formation from a homogeneous jet or at a nozzle is of great aesthetic appeal. In this paper, we introduce a low-cost setup for classroom use to produce quasi-high-speed recordings with high temporal and spatial resolution of the formation of drops at a nozzle. The visualization of the process can be used for quantitative analysis of the underlying physical phenomena.

},
author = {Sack, Achim and Pöschel, Thorsten},
doi = {10.1119/1.4979657},
faupublication = {yes},
journal = {American Journal of Physics},
peerreviewed = {Yes},
title = {{Dripping} faucet in extreme spatial and temporal resolution},
volume = {85},
year = {2017}
}
@article{faucris.106891444,
abstract = {The investigation of regular and irregular patterns in nonlinear oscillators is an outstanding problem in physics and in all natural sciences. In general, regularity is understood as tantamount to periodicity. However, there is now a flurry of works proving the existence of "antiperiodicity", an unfamiliar type of regularity. Here we report the experimental observation and numerical corroboration of antiperiodic oscillations. In contrast to the isolated solutions presently known, we report infinite hierarchies of antiperiodic waveforms that can be tuned continuously and that form wide spiral-shaped stability phases in the control parameter plane. The waveform complexity increases towards the focal point common to all spirals, a key hub interconnecting them all.},
author = {Freire, J. G. and Cabeza, C. and Marti, A. C. and Pöschel, Thorsten and Gallas, Jason},
doi = {10.1038/srep01958},
faupublication = {yes},
journal = {Scientific Reports},
peerreviewed = {Yes},
title = {{Antiperiodic} oscillations},
volume = {3},
year = {2013}
}
@article{faucris.123486264,
abstract = {We propose a new scheme for the two-way coupling of incompressible fluids and deformable bodies, where we focus on a medical application; in particular, secondary bone healing. Our method allows for accurate simulation and visualisation of the secondary bone healing process, which is used to optimise clinical treatment of bone fractures. In our simulation, the soft tissues are simulated as elastic materials using Strain Based Dynamics (SBD), and fluid is simulated using Incompressible Smoothed Particle Hydrodynamics (ISPH). The interaction model we propose works with any type of deformation technique as long as the object surface is represented by a polygonal mesh and the fluid by Lagrangian particles.},
author = {Aburumman, Nadine and Müller, Patric and Nair, Prapanch and Pöschel, Thorsten},
faupublication = {yes},
journal = {Eurographics technical report series},
peerreviewed = {No},
title = {{Coupled} {Simulation} of {Deformable} {Bodies} and {ISPH} {Fluids} for {Secondary} {Bone} {Healing}},
year = {2017}
}
@article{faucris.123449084,
abstract = {Soft particles are known to overlap and form stable clusters that self-assemble into periodic crystalline phases with density-independent lattice constants. We use molecular dynamics simulations in two dimensions to demonstrate that, through a judicious design of an isotropic pair potential, one can control the ordering of the clusters and generate a variety of phases, including decagonal and dodecagonal quasicrystals. Our results confirm analytical predictions based on a mean-field approximation, providing insight into the stabilization of quasicrystals in soft macromolecular systems, and suggesting a practical approach for their controlled self-assembly in laboratory realizations using synthesized soft-matter particles.},
author = {Engel, Michael and Barkan, Kobi and Lifshitz, Ron},
doi = {10.1103/PhysRevLett.113.098304},
faupublication = {no},
journal = {Physical Review Letters},
peerreviewed = {Yes},
title = {{Controlled} {Self}-{Assembly} of {Periodic} and {Aperiodic} {Cluster} {Crystals}},
volume = {113},
year = {2014}
}
@article{faucris.119189004,
abstract = {The flow of granular material in a rotating cylinder was simulated by molecular dynamics in two dimensions using spherical as well as nonspherical grains. At very low but constant angular velocity we found that the flow varies irregularly with time. The particles move in a stick-slip mode, i.e. there are avalanches of different size at the surface of the granular material. Observing the traces of the particles we found that there are unstable convection cells. Our results agree with recent experiments by Rajchenbach and Rolf. © 1995.},
author = {Pöschel, Thorsten and Buchholtz, Volkhard},
doi = {10.1016/0960-0779(94)00193-T},
faupublication = {no},
journal = {Chaos Solitons & Fractals},
peerreviewed = {Yes},
title = {{Complex} flow of granular material in a rotating cylinder},
volume = {5},
year = {1995}
}
@article{faucris.215873720,
abstract = {Colloids are rarely perfectly uniform but follow a distribution of sizes, shapes, and charges. This dispersity can be inherent (static) or develop and change over time (dynamic). Despite a long history of research, the conditions under which nonuniform particles crystallize and which crystal forms is still not well understood. Here, we demonstrate that hard spheres with Gaussian radius distribution and dispersity up to 19% always crystallize if compressed slowly enough, and they do so in surprisingly complex ways. This result is obtained by accelerating event-driven simulations with particle swap moves for static dispersity and particle resize moves for dynamic dispersity. Above 6% dispersity, AB(2) Laves, AB(13), and a region of Frank-Kasper phases are found. The Frank-Kasper region includes a quasicrystal approximant with Pearson symbol oS276. Our findings are relevant for ordering phenomena in soft matter and alloys.},
author = {Bommineni, Praveen Kumar and Varela-Rosales, Nydia Roxana and Klement, Marco and Engel, Michael},
doi = {10.1103/PhysRevLett.122.128005},
faupublication = {yes},
journal = {Physical Review Letters},
note = {CRIS-Team WoS Importer:2019-04-12},
peerreviewed = {Yes},
title = {{Complex} {Crystals} from {Size}-{Disperse} {Spheres}},
volume = {122},
year = {2019}
}
@article{faucris.109493164,
abstract = {Packings of hard polyhedra have been studied for centuries due to their mathematical aesthetic and more recently for their applications in fields such as nanoscience, granular and colloidal matter, and biology. In all these fields, particle shape is important for structure and properties, especially upon crowding. Here, we explore packing as a function of shape. By combining simulations and analytic calculations, we study three two- parameter families of hard polyhedra and report an extensive and systematic analysis of the densest known packings of more than 55 000 convex shapes. The three families have the symmetries of triangle groups ( icosahedral, octahedral, tetrahedral) and interpolate between various symmetric solids ( Platonic, Archimedean, Catalan). We find optimal ( maximum) packing- density surfaces that reveal unexpected richness and complexity, containing as many as 132 different structures within a single family. Our results demonstrate the importance of thinking about shape not as a static property of an object, in the context of packings, but rather as but one point in a higher- dimensional shape space whose neighbors in that space may have identical or markedly different packings. Finally, we present and interpret our packing results in a consistent and generally applicable way by proposing a method to distinguish regions of packings and classify types of transitions between them.},
author = {Engel, Michael and Chen, Elizabeth R. and Klotsa, Daphne and Damasceno, Pablo F. and Glotzer, Sharon C.},
doi = {10.1103/PhysRevX.4.011024},
faupublication = {no},
journal = {Physical Review X},
keywords = {Materials Science;Soft Matter},
peerreviewed = {unknown},
title = {{Complexity} in {Surfaces} of {Densest} {Packings} for {Families} of {Polyhedra}},
volume = {4},
year = {2014}
}
@article{faucris.114386184,
abstract = {We study the deterministic spin dynamics of an anisotropic magnetic particle in the presence of a magnetic field with a constant longitudinal and a time-dependent transverse component using the Landau-Lifshitz-Gilbert equation. We characterize the dynamical behavior of the system through calculation of the Lyapunov exponents, Poincaré sections, bifurcation diagrams, and Fourier power spectra. In particular we explore the positivity of the largest Lyapunov exponent as a function of the magnitude and frequency of the applied magnetic field and its direction with respect to the main anisotropy axis of the magnetic particle. We find that the system presents multiple transitions between regular and chaotic behaviors. We show that the dynamical phases display a very complicated structure of intricately intermingled chaotic and regular phases.},
author = {Gallas, Jason and Bragard, Jean and Suarez, Omar J. and Laroze, David and Pleiner, H. and Vargaz, P.},
doi = {10.1103/PhysRevE.84.037202},
faupublication = {yes},
journal = {Physical Review E},
pages = {037202},
peerreviewed = {Yes},
title = {{Chaotic} dynamics of a magnetic nanoparticle},
volume = {84},
year = {2011}
}
@article{faucris.213926450,
abstract = {The intensity of a monochromatic X-ray beam decreases exponentially with the distance it has traveled inside a material; this behavior is commonly referred to as Beer-Lambert's law. Knowledge of the material-specific attenuation coefficient mu allows us to determine the thickness of a sample from the intensity decrease the beam has experienced. However, classical X-ray tubes emit a polychromatic bremsstrahlung-spectrum. And the attenuation coefficients of all materials depend on the photon energy: photons with high energy are attenuated less than photons with low energy. In consequence, the X-ray spectrum changes while traveling through the medium; due to the relative increase in high energy photons, this effect is called beam hardening. For this varying spectrum, the Beer-Lambert law only remains valid if mu is replaced by an effective attenuation coefficient mu(eff) which depends not only on the material but also on its thickness x and the details of the X-ray setup used. We present here a way to deduce mu(eff)(x) from a small number of auxiliary measurements using a phenomenological model. This model can then be used to determine an unknown material thickness or in the case of a granular media its volume fraction. Published under license by AIP Publishing.},
author = {Baur, Manuel and Uhlmann, Norman and Pöschel, Thorsten and Schröter, Matthias},
doi = {10.1063/1.5080540},
faupublication = {yes},
journal = {Review of Scientific Instruments},
note = {CRIS-Team WoS Importer:2019-03-20},
peerreviewed = {Yes},
title = {{Correction} of beam hardening in {X}-ray radiograms},
volume = {90},
year = {2019}
}
@article{faucris.109900604,
abstract = {The velocity distribution of a granular gas is analyzed in terms of the Sonine polynomials expansion. We derive an analytical expression for the third Sonine coefficient a. In contrast to frequently used assumptions this coefficient is of the same order of magnitude as the second Sonine coefficient a. For small inelasticity the theoretical result is in good agreement with numerical simulations. The next-order Sonine coefficients a, and a are determined numerically. While these coefficients are negligible for small dissipation, their magnitude grows rapidly with increasing inelasticity for 0 < ε ≲ 0.6. We conclude that this behavior of the Sonine coefficients manifests the breakdown of the Sonine polynomial expansion caused by the increasing impact of the overpopulated high-energy tail of the distribution function. © EDP Sciences.},
author = {Brilliantov, Nikolai V. and Pöschel, Thorsten},
doi = {10.1209/epl/i2005-10555-6},
faupublication = {no},
journal = {EPL - Europhysics Letters},
pages = {424-430},
peerreviewed = {Yes},
title = {{Breakdown} of the {Sonine} expansion for the velocity distribution of granular gases},
volume = {74},
year = {2006}
}
@article{faucris.120054484,
abstract = {We investigate the motion of a hard cylinder rolling down a soft inclined plane. The cylinder is subjected to a viscous drag force and stochastic fluctuations due to the surrounding medium. In a wide range of parameters we observe bistability of the rolling velocity. In dependence on the parameters, increasing noise level may lead to increasing or decreasing average velocity of the cylinder. The approximative analytical theory agrees with numerical results.},
author = {Pöschel, Thorsten and Brilliantov, Nikolai V. and Zaikin, A.},
doi = {10.1209/epl/i2004-10350-y},
faupublication = {no},
journal = {EPL - Europhysics Letters},
pages = {371-377},
peerreviewed = {Yes},
title = {{Bistability} and noise-enhanced velocity of rolling motion},
volume = {69},
year = {2005}
}
@article{faucris.122866524,
abstract = {The dynamics of quasicrystals is more complicated than the dynamics of periodic solids and difficult to study in experiments. Here, we investigate a decagonal and a dodecagonal quasicrystal using molecular dynamics simulations of the Lennard-Jones-Gauss interaction system. We observe that the short-time dynamics is dominated by stochastic particle motion, so-called phason flips, which can be either single-particle jumps or correlated ringlike multi-particle moves. Over long times, the flip mechanism is efficient in reordering the quasicrystals and can generate diffusion. The temperature dependence of diffusion is described by an Arrhenius law. We also study the spatial distribution and correlation of mobile particles by analyzing the dynamic propensity.},
author = {Engel, Michael and Trebin, Hans-Rainer and Umezaki, Masahiro and Odagaki, Takashi},
doi = {10.1103/PhysRevB.82.134206},
faupublication = {no},
journal = {Physical Review B},
peerreviewed = {Yes},
title = {{Dynamics} of particle flips in two-dimensional quasicrystals},
volume = {82},
year = {2010}
}
@article{faucris.122956724,
abstract = {The collision of frictional granular particles may be described by an interaction force whose normal component is that of viscoelastic spheres while the tangential part is described by the model by Cundall and Strack (G´ eotechnique 29, 47 (1979)) being the most popular tangential collision model in Molecular Dynamics simulations. Albeit being a rather complicatedmodel, governed by 5 phenomenological parameters and 2 independent initial conditions, we find that it is described by 3 independent parameters only. Surprisingly, in a wide range of parameters the corresponding coefficient of tangential restitution, εt, is well described by the simple Coulomb law with a cut-off at εt = 0. A more complex behavior of the coefficient of restitution as a function on the normal and tangential components of the impact velocity, gn and gt, including negative values of εt, is found only for very small ratio gt/gn. For the analysis presented here we neglect dissipation of the interaction in normal direction.},
author = {Schwager, Thomas and Becker, Volker and Pöschel, Thorsten},
doi = {10.1140/epje/i2007-10356-3},
faupublication = {yes},
journal = {European Physical Journal E},
pages = {107--114},
peerreviewed = {Yes},
title = {{Coefficient} of tangential restitution for viscoelastic spheres},
volume = {27},
year = {2008}
}
@inproceedings{faucris.122077164,
abstract = {We investigate collective dissipative properties of vibrated granular materials by means of molecular dynamics simulations. The rate of energy loss indicates three different phases in the amplitude-frequency plane of the external forcing, namely solid, convective and gas-like regimes. The behavior of the effective damping decrement is consistent with the glassy nature of granular solids. The gas-like regime is most promising for practical applications.},
author = {Salueña, Clara and Esipov, Sergei E. and Pöschel, Thorsten and Simonian, Stephan S.},
booktitle = {Smart Structures and Materials 2002: Damping and Isolation},
doi = {10.1117/12.310696},
editor = {Agnes G.S.},
faupublication = {no},
keywords = {Damping regimes; Molecular Dynamics simulations},
pages = {23-29},
title = {{Dissipative} properties of granular ensembles},
venue = {San Diego, CA},
volume = {3327},
year = {1998}
}
@article{faucris.109896644,
abstract = {We present a simple model for the friction of two solid bodies moving against each other. In a self-consistent way we can obtain the dependence of the macroscopic friction force as a function of the driving velocity, the normal force and the ruggedness of the surfaces in contact. Our results are discussed in the context of friction laws used in earthquake models. © 1993.},
author = {Pöschel, Thorsten and Herrmann, Hans J.},
doi = {10.1016/0378-4371(93)90233-T},
faupublication = {no},
journal = {Physica A-Statistical Mechanics and Its Applications},
pages = {441-448},
peerreviewed = {Yes},
title = {{A} simple geometrical model for solid friction},
volume = {198},
year = {1993}
}
@article{faucris.121646184,
abstract = {
Granulare Medien, wie Sand, Salz, Kohle oder Kaffeebohnen, lassen sich

durch vertikales Schütteln entmischen. In Abhängigkeit von der

Schüttelamplitude sammeln sich die größeren Teilchen entweder an der

Oberfläche (der sogenannte Paranuss-Effekt), oder sie sinken nach

unten (inverser Paranuss-Effekt). Mit Experimenten, Computersimula-

tionen und Theorie ist es jüngst gelungen, die zu diesem Verhalten

führenden Mechanismen zu identifizieren [1, 2].

},
author = {Schröter, Matthias and Ulrich, Stephan},
doi = {10.1002/piuz.200790081},
faupublication = {no},
journal = {Physik in unserer Zeit},
pages = {266-267},
peerreviewed = {No},
title = {{Der} {Paranuss}-{Effekt}},
url = {http://onlinelibrary.wiley.com/doi/10.1002/piuz.200790081/epdf},
volume = {38},
year = {2007}
}
@article{faucris.119476324,
abstract = {
We show that the orientation and morphology of bedforms occurring on top of Pluto’s smooth ice coats are consistent with an aeolian origin under conditions of unidirectional flow. From scaling relations for dune size as a function of attributes of atmosphere and sediments, we find that the average diameter of the granular particles constituting such bedforms — assuming an aeolian origin — lies within the range 600 *μ*m< d < 750 *μ*m. Our findings show that, owing to the effect of hysteresis in the minimal threshold wind velocity for saltation, dune migration on Pluto can occur under wind speeds that are common to Earth and Mars.

},
author = {Ribeiro Parteli, Eric Josef and Pöschel, Thorsten},
doi = {10.1051/epjconf/201714014010},
faupublication = {yes},
journal = {EPJ Web of Conferences},
peerreviewed = {unknown},
title = {{Barchan} dunes on {Pluto}?},
volume = {140},
year = {2017}
}
@article{faucris.122572384,
abstract = {
Learning how to assemble inorganic nanoparticles into

ordered lattices may prove to be important for applications,

such as, electronics, photonics, and catalysis.

[1]

Indeed, theo-

retical studies have shown that certain types of crystalline

arrays of nanoparticles could potentially be used to generate

photonic band-gap materials, negative index materials, and

metamaterials at visible and infrared length scales.

[2,3]

The

vast majority of work in this area has focused on the assembly

of spherical particles. However, anisotropic nanoparticles,

which display rich assembly behavior owing to their reduced

symmetry, and have unique physical properties that can be

engineered by controlling interparticle spacing and orienta-

tion, may provide access to even more interesting materi-

als.

[4–8]

Moreover, they require design rules for predicting the

way such nanoparticles can assemble and the types of

structures that may be realized. The rapidly expanding library

of available anisotropic nanoparticle building blocks provides

exciting new opportunities to study colloidal assembly as

a function of particle shape.

[9–11]

},
author = {Engel, Michael and Young, Kaylie L. and Personick, Michelle L. and Damasceno, Pablo F. and Barnaby, Stacey N. and Bleher, Reiner and Li, Tao and Glotzer, Sharon C. and Lee, Byeongdu and Mirkin, Chad A.},
doi = {10.1002/anie.201306009},
faupublication = {no},
journal = {Angewandte Chemie-International Edition},
keywords = {depletion forces;entropy;nanomaterials;nanoparticles;surfactants},
pages = {13980-13984},
peerreviewed = {Yes},
title = {{A} {Directional} {Entropic} {Force} {Approach} to {Assemble} {Anisotropic} {Nanoparticles} into {Superlattices}},
volume = {52},
year = {2013}
}
@article{faucris.117267964,
abstract = {All hard, convex shapes are conjectured by Ulam to pack more densely than spheres(1), which have a maximum packing fraction of phi = pi/root 18 approximate to 0.7405. Simple lattice packings of many shapes easily surpass this packing fraction(2,3). For regular tetrahedra, this conjecture was shown to be true only very recently; an ordered arrangement was obtained via geometric construction with phi = 0.7786 (ref. 4), which was subsequently compressed numerically to phi = 0.7820 (ref. 5), while compressing with different initial conditions led to phi = 0.8230 ( ref. 6). Here we show that tetrahedra pack even more densely, and in a completely unexpected way. Following a conceptually different approach, using thermodynamic computer simulations that allow the system to evolve naturally towards high-density states, we observe that a fluid of hard tetrahedra undergoes a first-order phase transition to a dodecagonal quasicrystal(7-10), which can be compressed to a packing fraction of phi = 0.8324. By compressing a crystalline approximant of the quasicrystal, the highest packing fraction we obtain is phi = 0.8503. If quasicrystal formation is suppressed, the system remains disordered, jams and compresses to phi = 0.7858. Jamming and crystallization are both preceded by an entropy-driven transition from a simple fluid of independent tetrahedra to a complex fluid characterized by tetrahedra arranged in densely packed local motifs of pentagonal dipyramids that form a percolating network at the transition. The quasicrystal that we report represents the first example of a quasicrystal formed from hard or non-spherical particles. Our results demonstrate that particle shape and entropy can produce highly complex, ordered structures.},
author = {Engel, Michael and Haji-Akbari, Amir and Keys, Aaron S. and Zheng, Xiaoyu and Petschek, Rolfe G. and Palffy-Muhoray, Peter and Glotzer, Sharon C.},
doi = {10.1038/nature08641},
faupublication = {no},
journal = {Nature},
pages = {773-U91},
peerreviewed = {Yes},
title = {{Disordered}, quasicrystalline and crystalline phases of densely packed tetrahedra},
volume = {462},
year = {2009}
}
@article{faucris.122089924,
abstract = {We study the formation of capillary bridges between micrometer-sized glass spheres immersed in a binary liquid mixture using bright field and confocal microscopy. The bridges form upon heating due to the preferential wetting of the hydrophilic glass surface by the water-rich phase. If the system is cooled below the demixing temperature, the bridges disappear within a few seconds by intermolecular diffusion. Thus, this system oilers the opportunity to switch the bridges on and off and to tune precisely the bridge volume by altering the temperature in a convenient range. We measure the bridge geometry as a function or the temperature from bright field images and calculate the cohesive force. We discuss the influence of the solvent composition on the bridge formation temperature, the strength of the capillary force. and the bridge volume growth rate. Furthermore, we find that the onset of bridge formation coincides with the water-lutidine bulk coexistence curve.},
author = {Schröter, Matthias and Gögelein, Christoph and Brinkmann, Martin and Herminghaus, Stephan},
doi = {10.1021/la103062s},
faupublication = {no},
journal = {Langmuir},
pages = {17184-17189},
peerreviewed = {Yes},
title = {{Controlling} the {Formation} of {Capillary} {Bridges} in {Binary} {Liquid} {Mixtures}},
volume = {26},
year = {2010}
}
@phdthesis{faucris.109837464,
abstract = {Complex crystals and quasicrystals are ordered states of matter with very large or even infinite unit cells. Their particle dynamics and defects differ significantly from what is known for simple crystals: Local rearrangements – phason flips – and new types of dislocations are consequences of the structural complexity. In order to understand their behavior at an elementary level, we introduce three model systems in one and two dimensions. The systems are studied analytically and with numerical simulations. (i) The structure factors of the dynamic Fibonacci chain are computed with high resolution. They show a characteristic broadening of the phonon dispersion relation. The particle motion in real space reveals soliton and breather modes, closely connected to phason flips. (ii) Using a tiling model for the intermetallic system AlPdMn, experimental observations of metadislocations and the collective particle dynamics are explained. The Burgers vectors of stable dislocations are derived from energy considerations. (iii) In the Lennard-Jones-Gauss system a surprising variety of two-dimensional complex crystals as well as a decagonal and two dodecagonal quasicrystals are grown. The particles reorder by phason flips at elevated temperatures. During annealing, the entropically stabilized quasicrystals undergo reversible phase transitions into complex crystals. Competing interparticle distances seem to favor structural complexity. With the Lennard-Jones-Gauss system the growth, equilibrium dynamics, and defects of quasicrystals and complex crystals can be studied in simulations for the first time.},
author = {Engel, Michael},
doi = {10.18419/opus-4824},
faupublication = {no},
peerreviewed = {automatic},
school = {Friedrich-Alexander-Universität Erlangen-Nürnberg},
title = {{Dynamics} and {Defects} of {Complex} {Crystals} and {Quasicrystals}: {Perspectives} from {Simple} {Model} {Systems}},
year = {2008}
}
@incollection{faucris.218986067,
abstract = {Matter appears on our planet, in the solar system and in the rest of Universe in rather different forms.},
author = {Ebeling, Werner and Pöschel, Thorsten},
booktitle = {Lectures on Quantum Statistics},
doi = {10.1007/978-3-030-05734-3_1},
faupublication = {yes},
isbn = {978-3-030-05734-3},
note = {CRIS-Team Scopus Importer:2019-05-28},
pages = {1-17},
peerreviewed = {unknown},
publisher = {Springer Verlag},
series = {Lecture Notes in Physics},
title = {{Basic} physics of gases and plasmas},
volume = {953},
year = {2019}
}
@article{faucris.111557204,
abstract = {We study actively rotating granular particles manufactured by rapid prototyping. Such particles, as introduced in Ref. [1], convert vibrational motion into rotational motion via tilted elastic legs in a circular arrangement at the bottom of the particle. We extend the original design of the particles to make them suitable for mass-fabrication via rapid prototyping. The rotational velocity is measured in dependence of the driving frequency and amplitude. We find two different regimes of motion. For small amplitudes the particle performs a slow and stable rotation, while above a certain threshold the particle starts to perform a precission and consequently rotates significantly faster.},
author = {Scholz, Christian and Pöschel, Thorsten},
faupublication = {yes},
journal = {Revista Cubana de Fisica },
pages = {37-38},
peerreviewed = {unknown},
title = {{Actively} rotating granular particles manufactured by rapid prototyping},
url = {http://www.mss.cbi.fau.de/content/uploads/granular_particles_revcubfis_2016.pdf},
volume = {33},
year = {2016}
}
@article{faucris.114385524,
abstract = {We report a numerical characterization of the stability of semiconductor lasers with delayed feedback under the simultaneous variation of the delay time \textit{τ }and the pump current P. Changes in the number of External Cavity Modes are studied as a function of the delay time while the Regular Pulse Package regime is characterized as a function of the pump current. In addition, we describe some remarkable structures observed in the \textit{τ ×P }control plane, delimiting where these and other complex regimes of laser operation exist.},
author = {Gallas, Jason A. and Junges, Leandro and Pöschel, Thorsten},
doi = {10.1140/epjd/e2013-40124-4},
faupublication = {yes},
journal = {European Physical Journal D},
pages = {149--158},
peerreviewed = {Yes},
title = {{Characterization} of the stability of semiconductor lasers with delayed feedback according to the {Lang}-{Kobayashi} model},
volume = {67},
year = {2013}
}
@phdthesis{faucris.109481944,
abstract = {
English:

Recently a fingering morphology, resembling the hydrodynamic Saffman-Taylor instability, was identified in the quasi-two-dimensional electrodeposition of copper by M. Lòpez-Salvans et al. [Phys. Rev. Lett. 76, 4062 (1996)]. This thesis tries to elucidate the underlying mechanism by measuring the dispersion relation of the growing front.

The instability is accompanied by gravity-driven convection rolls at the electrodes, which are examined using particle image velocimetry. While at the anode the theory presented by Chazalviel et al. [J. Electroanal. Chem. 407, 61 (1996)] describes the convection roll, the flow field at the cathode is more complicated because of the growing deposit. In particular, the analysis of the orientation of the velocity vectors reveals some lag of the development of the convection roll compared to the finger envelope.

In thin-layer electrodeposition the dissipated electrical energy leads to a substantial heating of the ion solution. Measurements of the resulting temperature field by means of an infrared camera indicate, that its properties correspond closely with the development of the concentration field. In particular, we find that the thermal gradients at the electrodes act similar to a weak additional driving force to the convection rolls driven by concentration gradients.

Deutsch:

Die elektrolytische Abscheidung von Metallen in dünnen Zellen führt in Abhängigkeit von den experimentellen Parametern zu einer Vielzahl unterschiedlicher Morphologien. M. Lòpez-Salvans et al. [Phys. Rev. Lett. 76, 4062 (1996)] beobachten erstmals das Wachstum eines Deposits mit einer fingerartigen Hüllkurve. Als Elektrolyt dient eine Kupfersulfatlösung mit einer geringen Beigabe von Natriumsulfat. Unmittelbar vor dem wachsenden Deposit bildet sich eine Kupferhydroxidschicht aus. Die so entstehende Situation weist Ähnlichkeit mit der Saffman-Taylor-Instabilität auf, bei der ebenfalls Finger entstehen. Ziel der vorliegenden Arbeit ist es, durch Messungen, die als Grundlage einer theoretischen Modellierung dienen können, zum Verständnis des Fingerbildungsphänomens beizutragen. Hierzu werden drei verschiedene Fragestellungen untersucht:

(1) Zur Charakterisierung der initialen Phase der Instabilität wird die zeitliche Entwicklung der Fingerhüllkurve vermessen. Die einzelnen Moden des Fourierspektrums der Grenzlinie zeigen ein exponentielles Wachstum. Die Abhängigkeit der Wachstumsraten der Moden von deren Wellenzahl ergibt die Dispersionsrelation. Durch die gezielte Anregung einer kurzwelligen Mode mit Hilfe einer strukturierten Elektrode kann auch eine negative Wachstumsrate genau bestimmt werden. Für den Vergleich mit der Theorie wird die Abhängigkeit der Dispersionsrelation von den experimentellen Parametern Spannung, Zellhöhe und Zellneigung bestimmt.

(2) Die Änderung der Kupferionenkonzentration unmittelbar an den Elektroden geht mit einer Veränderung der Dichte des Elektrolyten einher. Diese führt je nach Elektrode zu einer Auf- oder Abwärtsströmung, die eine mit der Zeit anwachsende Konvektionsrolle antreibt. Das Entstehen dieser Konvektionsrolle lässt sich unterbinden, indem die Zelle in einer vertikalen Konfiguration betrieben wird. Diese unterdrückt jedoch auch die Fingerbildung. Zur Untersuchung des Strömungsfeldes in der Zelle werden dem Elektrolyten Tracerpartikel hinzugefügt und deren Bahnen mit Hilfe des Programmpaketes Artemis verfolgt. Ein Vergleich der an der Anode gemessenen Strömungsgeschwindigkeiten mit der Theorie von Chazalviel et al. [J. Electroanal. Chem. 407, 61 (1996)] zeigt befriedigende Ergebnisse. An der Katode schiebt das wachsende Deposit die Konvektionsrolle vor sich her, so dass deren Ausdehnung gegen einen festen Wert konvergiert.Ein Vergleich der Ausrichtung der Konvektionsrolle mit den Normalenvektoren der Fingerhüllkurve zeigt, dass zu Beginn der Instabilität die Entwicklung der Grenzlinie der des Strömungsfeldes vorauseilt.

(3) Die während eines Experimentes dissipierte elektrische Energie führt aufgrund des geringen Elektrolytvolumens zu einer messbaren Erwärmung. Dies wirft die Frage auf, ob hierbei Temperaturgradienten enstehen und zu Dichtegradienten führen, die die von den Konzentrationsunterschieden getriebenen Konvektionsrollen beeinflussen. Messungen des Temperaturfeldes mit einer Infrarotkamera zeigen, dass der Beitrag der Temperaturgradienten zur gesamten Dichtedifferenz kleiner als 4% bleibt.

},
author = {Schröter, Matthias},
faupublication = {no},
peerreviewed = {automatic},
school = {Friedrich-Alexander-Universität Erlangen-Nürnberg},
title = {{Die} {Fingermorphologie} in der {Elektrodeposition}, ein komplexes {Grenzflächenphänomen}},
year = {2003}
}
@article{faucris.122020404,
abstract = {We study the relation of permeability and morphology for porous structures composed of randomly placed overlapping circular or elliptical grains, so-called Boolean models. Microfluidic experiments and lattice Boltzmann simulations allowus to evaluate a power-lawrelation between theEuler characteristic of the conducting phase and its permeability. Moreover, this relation is so far only directly applicable to structures composed of overlapping grains where the grain density is known a priori. We develop a generalization to arbitrary structures modeled by Boolean models and characterized by Minkowski functionals. This generalization works well for the permeability of the void phase in systems with overlapping grains, but systematic deviations are found if the grain phase is transporting the fluid. In the latter case our analysis reveals a significant dependence on the spatial discretization of the porous structure, in particular the occurrence of single isolated pixels. To link the results to percolation theory we performed Monte Carlo simulations of the Euler characteristic of the open cluster, which reveals different regimes of applicability for our permeability-morphology relations close to and far away from the percolation threshold.},
author = {Scholz, Christian and Klatt, Michael and Mecke, Klaus and Wirner, Frank and Hirneise, Daniel and Schröder-Turk, Gerd and Bechinger, Clemens},
doi = {10.1103/PhysRevE.92.043023},
faupublication = {yes},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Direct} relations between morphology and transport in {Boolean} models},
volume = {92},
year = {2015}
}
@article{faucris.109620544,
abstract = {Mechanisms that stabilize quasicrystals are much discussed but not finally resolved. We confirm the random tiling hypothesis and its predictions in a fully atomistic decagonal quasicrystal model by calculating the free energy and the phason elastic constants over a wide range of temperatures. The Frenkel-Ladd method is applied for the phonon part, and an approach of uncorrelated phason flips is applied for the configurational part. When lowering the temperature, a phase transition to an approximant occurs. Close to the transition temperature, one of the phason elastic constants becomes soft. © 2012 American Physical Society.},
author = {Engel, Michael and Kiselev, Alexander and Trebin, Hans-Rainer},
doi = {10.1103/PhysRevLett.109.225502},
faupublication = {no},
journal = {Physical Review Letters},
peerreviewed = {Yes},
title = {{Confirmation} of the {Random} {Tiling} {Hypothesis} for a {Decagonal} {Quasicrystal}},
volume = {109},
year = {2012}
}
@article{faucris.114383324,
abstract = {We study complex oscillations generated by the de Pillis-Radunskaya model of cancer growth, a model including interactions between tumor cells, healthy cells, and activated immune system cells. We report a wide-ranging systematic numerical classification of the oscillatory states and of their relative abundance. The dynamical states of the cell populations are characterized here by two independent and complementary types of stability diagrams: Lyapunov and isospike diagrams. The model is found to display stability phases organized regularly in old and new ways: Apart from the familiar spirals of stability, it displays exceptionally long zig-zag networks and intermixed cascades of two- and three-doubling flanked stability islands previously detected only in feedback systems with delay. In addition, we also characterize the interplay between continuous spike-adding and spike-doubling mechanisms responsible for the unbounded complexification of periodic wave patterns. This article is dedicated to Prof. Hans Jürgen Herrmann on the occasion of his 60th birthday.},
author = {Gallas, Jason and Gallas, Michelle R. and Gallas, Marcia R.},
doi = {10.1140/epjst/e2014-02254-3},
faupublication = {yes},
journal = {European Physical Journal: Special Topics},
pages = {2131--2144},
peerreviewed = {unknown},
title = {{Distribution} of chaos and periodic spikes in a three-cell population model of cancer},
volume = {223},
year = {2014}
}
@article{faucris.109831744,
abstract = {We investigate the coefficient of normal restitution as a function of the impact velocity, ε(v), for inelastic spheres. We observe oscillating behavior of ε(v) which is superimposed to the known decay of the coefficient of restitution as a function of impact velocity. This remarkable effect was so far unnoticed because under normal circumstances it is screened by statistical scatter. We detected its clear signature by recording large amounts of data using an automated experiment. The new effect may be understood as an interplay between translational and vibrational degrees of freedom of the colliders. Both characteristics of the oscillation, the wavelength and the amplitude, agree quantitatively with a theoretical description of the experiment. © 2013 American Physical Society.},
author = {Müller, Patric and Heckel, Michael and Sack, Achim and Pöschel, Thorsten},
doi = {10.1103/PhysRevLett.110.254301},
faupublication = {yes},
journal = {Physical Review Letters},
peerreviewed = {Yes},
title = {{Complex} velocity dependence of the coefficient of restitution of a bouncing ball},
volume = {110},
year = {2013}
}
@article{faucris.109906984,
abstract = {The coefficient of restitution of a spherical particle in contact with a flat plate is investigated as a function of the impact velocity. As an experimental observation we notice nontrivial (non-Gaussian) fluctuations of the measured values. For a fixed impact velocity, the probability density of the coefficient of restitution, p, is formed by two exponential functions (one increasing, one decreasing) of different slope. This behavior may be explained by a certain roughness of the particle which leads to energy transfer between the linear and rotational degrees of freedom. © 2011 American Physical Society.},
author = {Montaine, Marina and Heckel, Michael and Kruelle, Christof and Schwager, Thomas and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.84.041306},
faupublication = {yes},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Coefficient} of restitution as a fluctuating quantity},
volume = {84},
year = {2011}
}
@article{faucris.122886984,
abstract = {The approximants xi, xi' and xi'(n) n of the Al-Mn-Pd quasi-crystal display interesting plastic properties, such as, for example, phason-induced deformation processes and metadislocations. Here we demonstrate that the phases and their deformed or defect states can be described by a simple projection formalism in three-dimensional space-not, as usual, in four to six dimensions. Using this method we can interpret the microstructures observed with electron microscopy as phasonic phase boundaries. Furthermore, we determine the metadislocations of lowest energy and relate them uniquely to experimentally observed ones. Since moving metadislocations in the xi' phase can create new phason planes, we suggest a dislocation-induced phase transition from xi' to xi'(n). The methods developed in this paper can also be applied for various other complex metallic alloys.},
author = {Engel, Michael and Trebin, Hans-Rainer},
doi = {10.1080/14786430500070669},
faupublication = {no},
journal = {Philosophical Magazine},
pages = {2227-2247},
peerreviewed = {Yes},
title = {{A} unified projection formalism for the {Al}-{Pd}-{Mn} quasi-crystal {Xi}-approximants and their metadislocations},
volume = {85},
year = {2005}
}
@masterthesis{faucris.110938124,
author = {Heckel, Michael and et al.},
author_hint = {heckel, m},
faupublication = {no},
peerreviewed = {automatic},
school = {Friedrich-Alexander-Universität Erlangen-Nürnberg},
support_note = {Author relations incomplete. You may find additional data in field 'author_hint'},
title = {{Dynamisches} {Verhalten} granularer {Materie} im {Schwingförderer}, {Diplomarbeit}},
year = {2007}
}
@article{faucris.109910724,
abstract = {The linear dashpot model for the inelastic normal force between colliding spheres leads to a constant coefficient of normal restitution, εn =const, which makes this model very popular for the investigation of dilute and moderately dense granular systems. For two frequently used models for the tangential interaction force we determine the coefficient of tangential restitution, εt, both analytically and by numerical integration of Newton's equation. Although εn =const for the linear-dashpot model, we obtain pronounced and characteristic dependences of the tangential coefficient on the impact velocity, εt = εt (g). The results may be used for event-driven simulations of granular systems of frictional particles. © 2008 The American Physical Society.},
author = {Becker, Volker and Schwager, Thomas and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.77.011304},
faupublication = {no},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Coefficient} of tangential restitution for the linear dashpot model},
volume = {77},
year = {2008}
}
@article{faucris.119643744,
abstract = {Dense granular clusters often behave like macro-particles. We address this interesting phenomenon in a model system of inelastically colliding hard disks inside a circular box, driven by a thermal wall at zero gravity. Molecular dynamics simulations show a close-packed cluster of almost circular shape, weakly fluctuating in space and isolated from the driving wall by a low-density gas. The density profile of the system agrees very well with the azimuthally symmetric solution of granular hydrostatic equations employing constitutive relations by Grossman et al., whereas the widely used Enskog-type constitutive relations show poor accuracy. We find that fluctuations of the center of mass of the system are Gaussian. This suggests an effective Langevin description in terms of a macro-particle, confined by a harmonic potential and driven by delta-correlated noise. Surprisingly, the fluctuations persist when increasing the number of particles in the system. © 2007 Springer-Verlag.},
author = {Meerson, Baruch and Díez-Minguito, Manuel and Schwager, Thomas and Pöschel, Thorsten},
doi = {10.1007/s10035-007-0055-1},
faupublication = {no},
journal = {Granular Matter},
keywords = {Granular cluster; Granular hydrodynamics; Strong fluctuations},
pages = {21-27},
peerreviewed = {Yes},
title = {{Close}-packed granular clusters: {Hydrostatics} and persistent {Gaussian} fluctuations},
volume = {10},
year = {2007}
}
@inproceedings{faucris.119619984,
abstract = {Additive manufacturing constitutes a promising production technology with potential application in a broad range of industrial areas. In this type of manufacturing process, objects are created from powder particles by adding layers of material upon one another through selectively melting particles from the powder bed. However, understanding the mechanical behavior of the powder during manufacturing as a function of material properties and particle shape is an essential pre-requisite for optimizing the production process. Here we develop a numerical tool for modeling the dynamics of powder particles during additive manufacturing based on force-based simulations by means of the Discrete Element Method (DEM). An existing DEM software (LIGGGHTS) is extended in order to study the transport of powder particles of complex geometric shapes through accounting for the boundary conditions inherent to the manufacturing proces},
author = {Ribeiro Parteli, Eric Josef},
booktitle = {AIP Conference Proceedings},
doi = {10.1063/1.4811898},
faupublication = {yes},
isbn = {9780735411661},
keywords = {additive manufacturing; DEM simulation; granular materials; multisphere method},
pages = {185-188},
title = {{DEM} simulation of particles of complex shapes using the multisphere method: {Application} for additive manufacturing},
venue = {Sydney, NSW},
volume = {1542},
year = {2013}
}
@article{faucris.117261584,
abstract = {Progress in nanocrystal synthesis and self-assembly enables the formation of highly ordered superlattices. Recent studies focused on spherical particles with tunable attraction and polyhedral particles with anisotropic shape, and excluded volume repulsion, but the effects of shape on particle interaction are only starting to be exploited. Here we present a joint experimental–computational multiscale investigation of a class of highly faceted planar lanthanide fluoride nanocrystals (nanoplates, nanoplatelets). The nanoplates self-assemble into long-range ordered tilings at the liquid–air interface formed by a hexane wetting layer. Using Monte Carlo simulation, we demonstrate that their assembly can be understood from maximization of packing density only in a first approximation. Explaining the full phase behaviour requires an understanding of nanoplate-edge interactions, which originate from the atomic structure, as confirmed by density functional theory calculations. Despite the apparent simplicity in particle geometry, the combination of shape-induced entropic and edge-specific energetic effects directs the formation and stabilization of unconventional long-range ordered assemblies not attainable otherwise.},
author = {Millan, Jaime A. and Murray, Christopher B. and Xing, Guozhong and Collins, Joshua E. and Kagan, Cherie R. and Engel, Michael and Chen, Jun and Qi, Liang and Li, Ju and Glotzer, Sharon C. and Li, Wenbin and Ye, Xingchen},
doi = {10.1038/nchem.1651},
faupublication = {no},
journal = {Nature Chemistry},
pages = {466-473},
peerreviewed = {Yes},
title = {{Competition} of shape and interaction patchiness for self-assembling nanoplates},
volume = {5},
year = {2013}
}
@article{faucris.109905884,
abstract = {As the kinetic equations become invalid, the constitutive relations (CRs), necessary for the closure of hydrodynamics, are not derivable from first-principles anymore. An ensemble of monodisperse, nearly elastic hard spheres in such conditions that the standard Navier-Stokes granular hydrodynamics (NSGH) breaks down becuase of large densities, not large inelasticity. This paper aims to check whether a variant of NSGH can still be used in an extreme case whether a variant of NSGH can still be used in an extreme case when the packing fraction is close to the maximum possible value, corresponding to hexagonal packing of spheres.},
author = {Meerson, Baruch and Pöschel, Thorsten and Bromberg, Yaron},
doi = {10.1103/PhysRevLett.91.024301},
faupublication = {no},
journal = {Physical Review Letters},
peerreviewed = {Yes},
title = {{Close}-packed floating clusters: {Granular} hydrodynamics beyond the freezing point?},
url = {http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.91.024301},
volume = {91},
year = {2003}
}
@inproceedings{faucris.122039984,
abstract = {Additive Fertigungsprozesse erfahren zurzeit zunehmendes Inte-resse aus Wirtschaft und Forschung, so zum Beispiel durch den Sonderforschungsbereich 814 (SFB 814) an der Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU). Der Arbeitskreis Modellierung innerhalb des SFB 814 widmet sich hierbei dem Auf- und Ausbau von grundlegendem Prozessverständnis mit dem Schwerpunkt auf pulver- und strahlbasierten Fertigungs-prozessen. Dies wird durch Anwendung komplexer Modelle er-reicht, welche die unterschiedlichen physikalischen Skalen und Effekte nachbilden. Der Schlüssel zum tieferen Prozessver-ständnis liegt dabei neben der eigentlichen Modellierung in der Verknüpfung der Einflüsse, die aus Effekten unterschiedlicher Größen- und Zeitskalen stammen. Das Ziel ist dabei stets die Optimierung des resultierenden Bauteils, vor allem hinsichtlich der Qualität der Oberfläche, der mechanischen Eigenschaften und der Wirtschaftlichkeit des Herstellungsprozesses.},
author = {Bauereiß, Andreas and Ribeiro Parteli, Eric Josef and Riedlbauer, Daniel-Rouven and Stingl, Michael},
booktitle = {Industriekolloqium des Sonderforschungsbereichs 814 – Additive Fertigung},
editor = {Dietmar Drummer},
faupublication = {yes},
pages = {117 - 130},
peerreviewed = {unknown},
title = {{Numerische} {Simulation} pulver- und strahlbasierter additiver {Fertigungsprozesse}},
year = {2012}
}
@article{faucris.120500204,
abstract = {The coefficient of restitution may be determined from the sound signal emitted by a sphere bouncing repeatedly off the ground. Although there is a large number of publications exploiting this method, so far, there is no quantitative discussion of the error related to this type of measurement. Analyzing the main error sources, we find that even tiny deviations of the shape from the perfect sphere may lead to substantial errors that dominate the overall error of the measurement. Therefore, we come to the conclusion that the well-established method to measure the coefficient of restitution through the emitted sound is applicable only for the case of nearly perfect spheres. For larger falling height, air drag may lead to considerable error, too.

},
author = {Heckel, Michael and Glielmo, Aldo and Gunkelmann, Nina and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.93.032901},
faupublication = {yes},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Can} we obtain the coefficient of restitution from the sound of a bouncing ball?},
url = {http://link.aps.org/doi/10.1103/PhysRevE.93.032901},
volume = {93},
year = {2016}
}
@article{faucris.109802924,
abstract = {A recent study claimed that heavy use of equations impedes communication among biologists, as measured by the ability to attract citations from peers. It was suggested that to increase the probability of being cited one should reduce the density of equations in papers, that equations should be moved to appendices, and that math training among biologists should be improved. Here, we report a detailed study of the citation habits among physicists, a community that has traditionally strong training and dependence on mathematical formulations. Is it possible to correlate statistical citation patterns and fear of mathematics in a community whose work strongly depends on equations? By performing a systematic analysis of the citation counts of papers published in one of the leading journals in physics covering all its disciplines, we find striking similarities with distribution of citations recorded in biological sciences. However, based on the standard deviations in citation data of both communities, biologists and physicists, we argue that trends in statistical indicators are not reliable to unambiguously blame mathematics for the existence or lack of citations. We digress briefly about other statistical trends that apparently would also enhance citation success.},
author = {Kollmer, Jonathan and Pöschel, Thorsten and Gallas, Jason},
doi = {10.1088/1367-2630/17/1/013036},
faupublication = {yes},
journal = {New Journal of Physics},
keywords = {citation strategies; science communication; social physics},
peerreviewed = {Yes},
title = {{Are} physicists afraid of mathematics?},
url = {http://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84922245151&origin=inward},
volume = {17},
year = {2015}
}
@article{faucris.122036024,
abstract = {Some dynamical properties for a dissipative time-dependent Lorentz gas are studied. We assume that the size of the scatterers change periodically in time. We show that for some combination of the control parameters the particles come to a complete stop between the scatterers, but for some other cases, the average velocity grows unbounded. This is the first time that the unlimited energy growth is observed in a dissipative system. Finally, we study the behavior of the average velocity as a function of the number of collisions and we show that the system is scaling invariant with scaling exponents well defined. © 2013 Elsevier B.V. All rights reserved.},
author = {Fregolente Mendes de Oliveira, Diego and Pöschel, Thorsten},
doi = {10.1016/j.physleta.2013.06.029},
faupublication = {yes},
journal = {Physics Letters A},
keywords = {Billiards; Chaos; Dissipation; Lorentz gas; Scaling},
pages = {2052-2057},
peerreviewed = {Yes},
title = {{Competition} between unlimited and limited energy growth in a two-dimensional time-dependent billiard},
volume = {377},
year = {2013}
}
@article{faucris.106318564,
abstract = {We present the densest known packing of regular tetrahedra with density phi = 4000/4671 = 0.856341 .... Like the recently discovered packings of Kallus et al. and Torquato-Jiao, our packing is crystalline with a unit cell of four tetrahedra forming two triangular dipyramids (dimer clusters). We show that our packing has maximal density within a three-parameter family of dimer packings. Numerical compressions starting from random configurations suggest that the packing may be optimal at least for small cells with up to 16 tetrahedra and periodic boundaries.},
author = {Engel, Michael and Glotzer, Sharon C. and Chen, Elizabeth R.},
doi = {10.1007/s00454-010-9273-0},
faupublication = {no},
journal = {Discrete & Computational Geometry},
keywords = {Crystallography;Packing;Regular solid;Hilbert problem},
pages = {253-280},
peerreviewed = {Yes},
title = {{Dense} {Crystalline} {Dimer} {Packings} of {Regular} {Tetrahedra}},
volume = {44},
year = {2010}
}
@article{faucris.109485684,
abstract = {Colloidal crystal structures with complexity and diversity rivaling atomic and molecular crystals have been predicted and obtained for hard particles by entropy maximization. However, thus far homochiral colloidal crystals, which are candidates for photonic metamaterials, are absent. Using Monte Carlo simulations we show that chiral polyhedra exhibiting weak directional entropic forces self-assemble either an achiral crystal or a chiral crystal with limited control over the crystal handedness. Building blocks with stronger faceting exhibit higher selectivity and assemble a chiral crystal with handedness uniquely determined by the particle chirality. Tuning the strength of directional entropic forces by means of particle rounding or the use of depletants allows for reconfiguration between achiral and homochiral crystals. We rationalize our findings by quantifying the chirality strength of each particle, both from particle geometry and potential of mean force and torque diagrams.},
author = {Engel, Michael and Damasceno, Pablo F. and Karas, Andrew S. and Schultz, Benjamin A. and Glotzer, Sharon C.},
doi = {10.1103/PhysRevLett.115.158303},
faupublication = {no},
journal = {Physical Review Letters},
peerreviewed = {Yes},
title = {{Controlling} {Chirality} of {Entropic} {Crystals}},
volume = {115},
year = {2015}
}
@article{faucris.115439764,
abstract = {We study the Rulkov model phase plane, a two-dimensional map-based model that describes

the behavior of a neuron. Keeping constant one of the three parameters, we obtain

phase planes showing well-defined periodicities. We show the importance of the parameter

identifying the periodicities and the number of spikes per burst, quantities that are related

between them by a linear relationship. The zones in which these periodicities are well-defined

exhibit in some cases, shapes similar to those appearing in some palm-tree patterns observed

both in trunks and in leaves. The detailed determination and description of these periodicity

zones could be the basis for a further study on synchronization of nonidentical neurons in

regions in which the domain of the parameter values ensure the fact to work with the same

periodicity. We also analyze the reliability and the limitations of this method.},
author = {RAM´IREZ ´A VILA, G.M. and Gallas, Marcia and Gallas, Jason},
faupublication = {yes},
journal = {Revista Boliviana de Física},
keywords = {Nonlinear dynamics and chaos, bifurcation theory, numerical simulations of chaotic systems, neuroscience, oscillations and resonance.},
peerreviewed = {Yes},
title = {{ANA}´ {LISIS} {DEL} {PLANO} {DE} {FASES} {DE} {UN} {MODELO} {DISCRETO} {DE} {NEURONA} {BASADO} {EN} {LA} {DETERMINACIO}´ {N} {DE} {PERIODICIDADES} {PHASE} {PLANE} {ANALYSIS} {OF} {A} {NEURON} {MAP}-{BASED} {MODEL} {BY} {DETERMINING} {PERIODICITIES}},
volume = {27},
year = {2015}
}
@article{faucris.122864764,
abstract = {Figure Persented: Polyhedra and their arrangements have intrigued humankind since the ancient Greeks and are today important motifs in condensed matter, with application to many classes of liquids and solids. Yet, little is known about the thermodynamically stable phases of polyhedrally shaped building blocks, such as faceted nanoparticles and colloids. Although hard particles are known to organize due to entropy alone, and some unusual phases are reported in the literature, the role of entropic forces in connection with polyhedral shape is not well understood. Here, we study thermodynamic self-assembly of a family of truncated tetrahedra and report several atomic crystal isostructures, including diamond, β-tin, and high-pressure lithium, as the polyhedron shape varies from tetrahedral to octahedral. We compare our findings with the densest packings of the truncated tetrahedron family obtained by numerical compression and report a new space-filling polyhedron, which has been overlooked in previous searches. Interestingly, the self-assembled structures differ from the densest packings. We show that the self-assembled crystal structures can be understood as a tendency for polyhedra to maximize face-to-face alignment, which can be generalized as directional entropic forces. © 2011 American Chemical Society.},
author = {Engel, Michael and Damasceno, Pablo F. and Glotzer, Sharon C.},
doi = {10.1021/nn204012y},
faupublication = {no},
journal = {Acs Nano},
keywords = {computer simulation; directional entropy; nanoparticles; polyhedra packing; self-assembly; space-filling},
pages = {609-614},
peerreviewed = {Yes},
title = {{Crystalline} assemblies and densest packings of a family of truncated tetrahedra and the role of directional entropic forces},
volume = {6},
year = {2012}
}
@article{faucris.122106204,
abstract = {The dynamics of sheared inelastic-hard-sphere systems is studied using nonequilibrium molecular-dynamics simulations and direct simulation Monte Carlo. In the molecular-dynamics simulations Lees-Edwards boundary conditions are used to impose the shear. The dimensions of the simulation box are chosen to ensure that the systems are homogeneous and that the shear is applied uniformly. Various system properties are monitored, including the one-particle velocity distribution, granular temperature, stress tensor, collision rates, and time between collisions. The one-particle velocity distribution is found to agree reasonably well with an anisotropic Gaussian distribution, with only a slight overpopulation of the high-velocity tails. The velocity distribution is strongly anisotropic, especially at lower densities and lower values of the coefficient of restitution, with the largest variance in the direction of shear. The density dependence of the compressibility factor of the sheared inelastic-hard-sphere system is quite similar to that of elastic-hard-sphere fluids. As the systems become more inelastic, the glancing collisions begin to dominate over more direct, head-on collisions. Examination of the distribution of the times between collisions indicates that the collisions experienced by the particles are strongly correlated in the highly inelastic systems. A comparison of the simulation data is made with direct Monte Carlo simulation of the Enskog equation. Results of the kinetic model of Montanero [J. Fluid Mech. 389, 391 (1999)] based on the Enskog equation are also included. In general, good agreement is found for high-density, weakly inelastic systems. © 2009 The American Physical Society.},
author = {Bannerman, Marcus and Green, Thomas E. and Lue, Leo and Grassia, Paul},
doi = {10.1103/PhysRevE.79.041308},
faupublication = {yes},
journal = {Physical Review E},
peerreviewed = {Yes},
title = {{Collision} statistics in sheared inelastic hard spheres},
volume = {79},
year = {2009}
}
@inproceedings{faucris.119278764,
abstract = {We present three heuristics including the usage of domain specific knowledge to improve a general purpose algorithm for the 3D approximate point set match problem and its application to the task of finding 3D motifs (like surface patterns or binding sites) in proteins. The domain specific knowledge and further heuristics are used, under certain conditions, to reduce the run time for the search and to adapt the number of reported matches to the expectations of the user. Compared to the general purpose algorithm, the new version is twice as fast, and can be further improved especially for small tolerances in the matches by means of analyzing the distance distributions of the atoms.},
author = {Formella, Arno and Pöschel, Thorsten and Sanchez Chao, Castor},
booktitle = {14th Portuguese Conference on Artificial Intelligence},
date = {2009-10-12/2009-10-15},
faupublication = {yes},
pages = {101 - 112},
peerreviewed = {unknown},
title = {{Approximate} {3D} motif search in proteins with domain specific knowledge. {New} {Trends} in {Artificial} {Intelligence}},
venue = {Aveiro},
year = {2009}
}
@article{faucris.109922604,
abstract = {We investigate collective dissipative properties of vibrated granular materials by means of molecular-dynamics simulations. Rates of energy losses indicate three different regimes or "phases" in the amplitude-frequency plane of the external forcing, namely solid, convective, and gaslike regimes. The behavior of effective damping decrement in the solid regime is glassy. Practical applications are discussed. ©1999 The American Physical Society.},
author = {Salueña, Clara and Pöschel, Thorsten and Esipov, Sergei E.},
doi = {10.1103/PhysRevE.59.4422},
faupublication = {no},
journal = {Physical Review E},
pages = {4422-4425},
peerreviewed = {Yes},
title = {{Dissipative} properties of vibrated granular materials},
volume = {59},
year = {1999}
}
@article{faucris.114384644,
abstract = {A recent conjecture in this Journal, concerning the existence of spiral stability phases in Hartley’s oscillator, is corroborated amply. We report numerically computed stability phase diagrams indicating precisely where spirals of periodicity and chaos may be found in several control planes of the system. In addition, we describe some remarkable parameter loops in control space which allow one to trace identical dynamical behaviors by tuning totally independent parameters.},
author = {Gallas, Jason A. and Gallas, Jason and Freire, J. G.},
doi = {10.1016/j.chaos.2013.12.007},
faupublication = {yes},
journal = {Chaos Solitons & Fractals},
pages = {129--134},
peerreviewed = {Yes},
title = {{Cyclic} organization of stable periodic and chaotic pulsations in {Hartley}’s oscillator},
volume = {59},
year = {2014}
}
@article{faucris.109817224,
abstract = {We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase orderly without bound. Such complex patterns emerge forming self-similar discontinuous phases that combine in an artful way to produce large discontinuous spirals of stability. This unanticipated discrete accumulation of stability phases was detected experimentally and numerically in a Duffing-like proxy specially designed to bypass noisy spectra conspicuously present in driven oscillators. Discontinuous spirals organize the dynamics over extended parameter intervals around a focal point. They are useful to optimize locking into desired oscillatory modes and to control complex systems. The organization of oscillations into discontinuous spirals is expected to be generic for a class of nonlinear oscillators.},
author = {Sack, Achim and Freire, J. G. and Lindberg, Erik and Pöschel, Thorsten and Gallas, Jason},
doi = {10.1038/srep03350},
faupublication = {yes},
journal = {Scientific Reports},
peerreviewed = {Yes},
title = {{Discontinuous} spirals of stable periodic oscillations},
volume = {3},
year = {2013}
}
@inproceedings{faucris.122570184,
author = {Engel, Michael},
booktitle = {Aperiodic 2015},
date = {2015-08-30/2015-09-04},
faupublication = {no},
peerreviewed = {unknown},
title = {{Cabinet} of curiosities: self-assembly of unusual crystal structures},
venue = {Prag},
year = {2015}
}
@article{faucris.109805124,
abstract = {We consider the motion of an aspherical inelastic particle of dumbbell type bouncing repeatedly on a horizontal flat surface. The coefficient of restitution of such a particle depends not only on material properties and impact velocity but also on the angular orientation at the instant of the collision whose variance is considerable, even for small eccentricity. Assuming random angular orientation of the particle at the instant of contact we characterize the measured coefficient of restitution as a fluctuating quantity and obtain a wide probability density function including a finite probability for negative values of the coefficient of restitution. This may be understood from the partial exchange of translational and rotational kinetic energy.},
author = {Glielmo, Aldo and Gunkelmann, Nina and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.90.052204},
faupublication = {yes},
journal = {Physical Review E - Statistical, Nonlinear, and Soft Matter Physics},
peerreviewed = {Yes},
title = {{Coefficient} of restitution of aspherical particles},
volume = {90},
year = {2014}
}
@inproceedings{faucris.119875624,
abstract = {We develop an analytical theory of adhesive interaction of viscoelastic spheres in quasistatic approximation. Deformations and deformation rates are assumed to be small, which allows for the application of the Hertz contact theory, modified to account for viscoelastic forces. The adhesion interactions are described by the Johnson, Kendall, and Roberts theory. Using the quasistatic approximation we derive the total force between the bodies which is not sufficiently described by the superposition of elastic, viscous and adhesive contributions, but instead an additional cross-term appears, which depends on the elastic, viscous and adhesive parameters of the material. Using the derived theory we estimate the contribution of adhesive forces to the normal coefficient of restitution and derive a criterion for the validity of the viscoelastic collision model. © 2005 Taylor & Francis Group.},
author = {Brilliantov, Nikolai V. and Pöschel, Thorsten},
booktitle = {5th International Conference on the Micromechanics of Granular Media: Powders and Grains 2005},
faupublication = {no},
isbn = {9780415383479},
pages = {505-508},
title = {{Adhesive} interactions of viscoelastic spheres},
url = {https://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=84857585813&origin=inward},
venue = {Stuttgart},
volume = {1},
year = {2005}
}
@article{faucris.120048324,
abstract = {A numerical study that aims to analyze the thermal mechanisms of unsteady, supersonic granular flow by means of hydrodynamic simulations of the Navier-Stokes granular equation is reported in this paper. For this purpose, a paradigmatic problem in granular dynamics such as the Faraday instability is selected. Two different approaches for the Navier-Stokes transport coefficients for granular materials are considered, namely the traditional Jenkins-Richman theory for moderately dense quasi-elastic grains and the improved Garzó-Dufty-Lutsko theory for arbitrary inelasticity, which we also present here. Both the solutions are compared with event-driven simulations of the same system under the same conditions, by analyzing the density, temperature and velocity field. Important differences are found between the two approaches, leading to interesting implications. In particular, the heat transfer mechanism coupled to the density gradient, which is a distinctive feature of inelastic granular gases, is responsible for a major discrepancy in the temperature field and hence in the diffusion mechanisms. © IOP Publishing and Deutsche Physikalische Gesellschaft.},
author = {Garzó, Vicente and Almazán Torres, Lidia and Carrillo, José A. and Salueña, Clara and Pöschel, Thorsten},
doi = {10.1088/1367-2630/15/4/043044},
faupublication = {yes},
journal = {New Journal of Physics},
peerreviewed = {Yes},
title = {{A} numerical study of the {Navier}-{Stokes} transport coefficients for two-dimensional granular hydrodynamics},
volume = {15},
year = {2013}
}
@article{faucris.122141844,
abstract = {We analyze the velocity distribution function of force-free granular gases in the regime of homogeneous cooling when deviations from the Maxwellian distribution may be accounted only by the leading term in the Sonine polynomial expansion, quantified by the second coefficient a. We go beyond the linear approximation for a and find three different values (three roots) for this coefficient which correspond to a scaling solution of the Boltzmann equation. The stability analysis performed showed, however, that among these three roots only one corresponds to a stable scaling solution. This is very close to a, obtained in previous studies in a linear with respect to a approximation.},
author = {Brilliantov, Nikolai and Pöschel, Thorsten},
doi = {10.1103/PhysRevE.61.2809},
faupublication = {no},
journal = {Physical Review E},
pages = {2809-2812},
peerreviewed = {Yes},
title = {{Deviation} from {Maxwell} distribution in granular gases with constant restitution coefficient},
volume = {61},
year = {2000}
}
@article{faucris.213262130,
abstract = {DNA-programmable assembly has been used to deliberately synthesize hundreds of different colloidal crystals spanning dozens of symmetries, but the complexity of the achieved structures has so far been limited to small unit cells. We assembled DNA-modified triangular bipyramids (~250-nanometer long edge, 177-nanometer short edge) into clathrate architectures. Electron microscopy images revealed that at least three different structures form as large single-domain architectures or as multidomain materials. Ordered assemblies, isostructural to clathrates, were identified with the help of molecular simulations and geometric analysis. These structures are the most sophisticated architectures made via programmable assembly, and their formation can be understood based on the shape of the nanoparticle building blocks and mode of DNA functionalization.},
author = {Lin, Haixin and Lee, Sangmin and Sun, Lin and Spellings, Matthew and Engel, Michael and Glotzer, Sharon C. and Mirkin, Chad A.},
doi = {10.1126/science.aal3919},
faupublication = {yes},
journal = {Science},
note = {EAM Import::2019-03-13},
pages = {931-935},
peerreviewed = {Yes},
title = {{Clathrate} colloidal crystals},
volume = {355},
year = {2017}
}
@incollection{faucris.116681664,
address = {New York},
author = {Ribeiro Parteli, Eric Josef},
booktitle = {Encyclopedia of Planetary Landforms},
editor = {Hargitai, H., Kereszturi, Ákos},
faupublication = {yes},
pages = {1 - 2},
peerreviewed = {unknown},
publisher = {Springer},
title = {{Drop} {Dune}},
year = {2014}
}
@article{faucris.114389704,
abstract = {Investigating how tightly objects pack space is a long-standing problem, with relevance for many disciplines from discrete mathematics to the theory of glasses. Here we report on the fundamental yet so far overlooked geometric property that disordered mono-disperse spherical bead packs have significant local structural anisotropy manifest in the shape of the free space associated with each bead. Jammed disordered packings from several types of experiments and simulations reveal very similar values of the cell anisotropy, showing a linear decrease with packing fraction. Strong deviations from this trend are observed for unjammed configurations and for partially crystalline packings above 64%. These findings suggest an inherent geometrical reason why, in disordered packings, anisotropic shapes can fill space more efficiently than spheres, and have implications for packing effects in non-spherical liquid crystals, foams and structural glasses.},
author = {Schröder-Turk, Gerd and Mickel, Walter and Schröter, Matthias and Delaney, Gary and Saadatfar, Mohammad and Senden, T.J. and Mecke, Klaus and Aste, T.},
doi = {10.1209/0295-5075/90/34001},
faupublication = {yes},
journal = {EPL - Europhysics Letters},
pages = {34001},
peerreviewed = {Yes},
title = {{Disordered} spherical bead packs are anisotropic},
volume = {90},
year = {2010}
}
@inproceedings{faucris.123991604,
abstract = {It has recently been established that sand is mobile under the current Martian cli-mate, including at the North Pole [1,2]. Here we present a detailed study of the morphometry and migration of barchan and dome dunes in the North Polar Region of Mars.},
author = {Ribeiro Parteli, Eric Josef and Bourke, Mary C. and Byrne, S. and Berman, D.},
booktitle = {Third International Planetary Dunes Workshop},
faupublication = {yes},
peerreviewed = {unknown},
title = {{Dune} migration in the north polar region of {Mars}},
year = {2012}
}
@article{faucris.122021064,
abstract = {We study some dynamical properties for the problem of a charged particle in an electric field considering both the low velocity and relativistic cases. The dynamics for both approaches is described in terms of a two-dimensional and nonlinear mapping. The structure of the phase spaces is mixed and we introduce a hole in the chaotic sea to let the particles to escape. By changing the size of the hole we show that the survival probability decays exponentially for both cases. Additionally, we show for the relativistic dynamics, that the introduction of dissipation changes the mixed phase space and attractors appear. We study the parameter space by using the Lyapunov exponent and the average energy over the orbit and show that the system has a very rich structure with infinite family of self-similar shrimp shaped embedded in a chaotic region. © 2012 Elsevier B.V.},
author = {Fregolente Mendes de Oliveira, Diego and Leonel, Edson D.},
doi = {10.1016/j.physleta.2012.10.052},
faupublication = {yes},
journal = {Physics Letters A},
keywords = {Chaos; Parameter space; Shrimps; Survival probability},
pages = {3630-3637},
peerreviewed = {Yes},
title = {{Dynamical} properties for the problem of a particle in an electric field of wave packet: {Low} velocity and relativistic approach},
volume = {376},
year = {2012}
}
@book{faucris.122766204,
abstract = {Computer simulations not only belong to the most important methods for the theoretical investigation of granular materials, but also provide the tools that have enabled much of the expanding research by physicists and engineers. The present book is intended to serve as an introduction to the application of numerical methods to systems of granular particles. Accordingly, emphasis is placed on a general understanding of the subject rather than on the presentation of the latest advances in numerical algorithms. Although a basic knowledge of C++ is needed for the understanding of the numerical methods and algorithms in the book, it avoids usage of elegant but complicated algorithms to remain accessible for those who prefer to use a different programming language. While the book focuses more on models than on the physics of granular material, many applications to real systems are presented. © Springer-Verlag Berlin Heidelberg 2005.},
author = {Pöschel, Thorsten and Schwager, Thomas},
doi = {10.1007/3-540-27720-X},
faupublication = {no},
isbn = {9783540214854},
pages = {1-322},
publisher = {Springer Berlin Heidelberg},
title = {{Computational} granular dynamics: {Models} and algorithms},
year = {2005}
}
@article{faucris.117058744,
abstract = {Icosahedral quasicrystals (IQCs) are a form of matter that is ordered but not periodic in any direction. All reported IQCs are intermetallic compounds and either of face-centred-icosahedral or primitive-icosahedral type, and the positions of their atoms have been resolved from diffraction data. However, unlike axially symmetric quasicrystals, IQCs have not been observed in non-atomic (that is, micellar or nanoparticle) systems, where real-space information would be directly available. Here, we show that an IQC can be assembled by means of molecular dynamics simulations from a one-component system of particles interacting via a tunable, isotropic pair potential extending only to the third-neighbour shell. The IQC is body-centred, self-assembles from a fluid phase, and in parameter space neighbours clathrates and other tetrahedrally bonded crystals. Our findings elucidate the structure and dynamics of the IQC, and suggest routes to search for it and design it in soft matter and nanoscale systems.},
author = {Engel, Michael and Damasceno, Pablo F. and Glotzer, Sharon C. and Philips, Carolyn L.},
doi = {10.1038/nmat4152},
faupublication = {no},
journal = {Nature Materials},
pages = {109-116},
peerreviewed = {unknown},
title = {{Computational} self-assembly of a one-component icosahedral quasicrystal},
volume = {14},
year = {2014}
}