124 citations · 805 across the 41 of their papers we have counts for
18 papers · 1 filter
Measuring magnetic moments of polydisperse ferrofluids utilizing the inverse Langevin function
Ingo Rehberg, Reinhard Richter, Stefan Hartung +3
The dipole strength of magnetic particles in a suspension is obtained by a graphical rectification of the magnetization curves based on the inverse Langevin function. The method yi…
Graphical Magnetogranulometry of EMG909
Ingo Rehberg, Reinhard Richter, Stefan Hartung
The magnetization curve of the ferrofluid EMG909 is measured. It can adequately be described by a superposition of four Langevin terms. The effective dipole strength of the magneti…
Dotriacontapoles -- almost self-assembled
Stefan Hartung, Felix Sommer, Simeon Völkel +2
The magnetic field of a cuboidal cluster of eight magnetic spheres is measured. It decays with the inverse seventh power of the distance. This corresponds formally to a hitherto un…
Self-assembly of magnetic iron oxide nanoparticles into cuboidal superstructures
Sabine Rosenfeldt, Stephan Förster, Thomas Friedrich +2
This chapter describes the synthesis and some characteristics of magnetic iron oxide nanoparticles, mainly nanocubes, and focus on their self-assembly into crystalline cuboids in d…
Exploring cogging free magnetic gears
Stefan Borgers, Simeon Völkel, Wolfgang Schöpf +1
The coupling of two rotating spherical magnets is investigated experimentally, with particular emphasis on those motions where the driven magnet follows the driving one with a unif…
Pattern formation in wet granular matter under vertical vibrations
Lorenz Butzhammer, Simeon Völkel, Ingo Rehberg +1
Experiments on a thin layer of cohesive wet granular matter under vertical vibrations reveal kink separated domains that collide with the container at different phases. Due to the…
Ordering in granular rod monolayers driven far from thermodynamic equilibrium
Thomas Müller, Daniel de las Heras, Ingo Rehberg +1
The orientational order in vertically agitated granular rod monolayers is investigated experimentally and compared quantitatively with equilibrium Monte Carlo simulations and densi…
Infinite Geometric Frustration in a Cubic Dipole Cluster
Johannes Schönke, Tobias M. Schneider, Ingo Rehberg
The geometric arrangement of interacting (magnetic) dipoles is a question of fundamental importance in physics, chemistry and engineering. Motivated by recent progress concerning t…
Dynamics of rotating spirals in agitated wet granular matter
Kai Huang Lorenz Butzhammer, Ingo Rehberg
Pattern formation of a thin layer of vertically agitated wet granular matter is investigated experimentally. Due to the strong cohesion arising from the capillary bridges formed be…
Scaling of the normal coefficient of restitution for wet impacts
Thomas Mueller, Frank Gollwitzer, Christof Kruelle +2
A thorough understanding of the energy dissipation in the dynamics of wet granular matter is essential for a continuum description of natural phenomena such as debris flow, and the…
Analogue of surface melting in a macroscopic non-equilibrium system
Christopher May, Michael Wild, Ingo Rehberg +1
Agitated wet granular matter can be considered as a nonequilibrium model system for phase transitions, where the macroscopic particles replace the molecules and the capillary bridg…
Coefficient of restitution for wet particles
Frank Gollwitzer, Ingo Rehberg, Christof A. Kruelle +1
The influence of a wetting liquid on the coefficient of restitution (COR) is investigated experimentally by tracing freely falling particles bouncing on a wet surface. The dependen…
Observation of Density Segregation inside Migrating Dunes
Christopher Groh, Ingo Rehberg, Christof A. Kruelle
Spatiotemporal patterns in nature, such as ripples or dunes, formed by a fluid streaming over a sandy surface show complex behavior despite their simple forms. Below the surface, t…
Period tripling causes rotating spirals in agitated wet granular layers
Kai Huang, Ingo Rehberg
Pattern formation of a thin layer of vertically agitated wet granular matter is investigated experimentally. Rotating spirals with three arms, which correspond to the kinks between…
Surface Instabilities and Magnetic Soft Matter
Christian Gollwitzer, Marina Krekhova, Guenter Lattermann +2
We report on the formation of surface instabilities in a layer of thermoreversible ferrogel when exposed to a vertical magnetic field. Both static and time dependent magnetic field…
Measuring the deformation of a ferrogel sphere in a homogeneous magnetic field
Christian Gollwitzer, Alexander Turanov, Marina Krekhova +3
A sphere of a ferrogel is exposed to a homogeneous magnetic field. In accordance to theoretical predictions, it gets elongated along the field lines. The time-dependence of the ela…
Reversing a granular flow on a vibratory conveyor
R. Grochowski, P. Walzel, M. Rouijaa +2
Experimental results are presented on the transport properties of granular materials on a vibratory conveyor. For circular oscillations of the shaking trough a non-monotonous depen…
Axial Sand-Water Segregation
A. P. J. Breu, C. A. Kruelle, I. Rehberg
A novel pattern forming instability in a mixture of a granular material and water in a horizontal rotating drum is experimentally investigated. The particles accumulate in radial s…