相关论文: A study of the size of snow particles in powder sn…
Instabilities and avalanches in granular flows represent hallmarks of failure: they can both disrupt industrial process flows and signal dangerous conditions, like those in grain silos and snowy mountaintops. We investigate intermittency…
We study the size and shape of the final deposit obtained when a drop with colloidal particles has dried on a super-hydrophobic surface made of micro-posts. As expected, most of the particles lie inside a circular area, which radius roughly…
The accumulation of small particles is analyzed in stationary flows through channels of variable width at small Reynolds number. The combined influence of pressure, viscous drag and thermal fluctuations is described by means of a…
We introduce a simple model for the size distribution of avalanches based on the idea that the front of an avalanche can be described by a directed random walk. The model captures some of the qualitative features of earthquakes, avalanches…
In this study, we have investigated the fluctuations of particle motion, i.e. the non-affine motion, during the avalanche process, discovering a rich dynamics from the microscopic to the macroscopic scales. We find that there is strong…
We quantitatively investigate how collisional avalanches may developin debris discs as the result of the initial break-up of a planetesimal or comet-like object, triggering a collisional chain reaction due to outward escaping small dust…
We report experimental measurements of avalanche behavior of thin granular layers on an inclined plane for low volume flow rate. The dynamical properties of avalanches were quantitatively and qualitatively different for smooth glass beads…
Experiments are performed in which dust particles are levitated at varying heights above the powered electrode in a RF plasma discharge by changing the discharge power. The trajectories of particles dropped from the top of the discharge…
Every solid particle in the atmosphere, from ice crystals and pollen to dust, ash, and microplastics, is non-spherical. These particles play significant roles in Earth's climate system, influencing temperature, weather patterns, natural…
For many decades vertical winds have been observed at high altitudes of the Earth's atmosphere, in the mesosphere and thermosphere layers. These observations have been used with a simple one dimensional model to make estimates of possible…
Local magnetization measurements on 100 nm type-II superconducting Pb thin films show that flux penetration changes qualitatively with temperature. Small flux jumps at the lowest temperatures gradually increase in size, then disappear near…
We study the phenomenon of internal avalanching within the context of recently introduced lattice models of granular media. The avalanche is produced by pulling out a grain at the base of the packing and studying how many grains have to…
We investigate the sliding of objects on an inclined granular surface close to the avalanche threshold. Our experiments show that the stability is driven by the surface deformations. Heavy objects generate footprint-like deformations which…
When modeling the density and grain size distribution in debris disks, the minimum particle size is often significantly larger than the corresponding blowout size. While the dust particles are usually modeled as compact, homogenous spheres,…
Large scale computer simulations are presented to investigate the avalanche statistics of sand piles using molecular dynamics. We could show that different methods of measurement lead to contradicting conclusions, presumably due to…
We investigate the effects of temperature variance, grain size variation, flow regimes, and the use of Support Vector Machines (SVMs) in avalanche studies. The temperature variance experiments involved ice single crystals and polycrystals,…
We observe ripples forming on the surface of a granular powder in a container submitted from below to a series of brief and distinct shocks. After a few taps, the pattern turns out to be stable against any further shock of the same…
The size of the stable elementary particles is investigated with the standing wave model. The particle size follows from the magnitude of the radiation pressure. It is shown that the outward directed radiation pressure is balanced by the…
We investigate dust growth due to settling in a 1D vertical column of a protoplanetary disk. It is known from the observed 10 micron feature in disk SEDs, that small micron-sized grains are present at the disk atmosphere throughout the…
In disordered elastic systems, driven by displacing a parabolic confining potential adiabatically slowly, all advance of the system is in bursts, termed avalanches. Avalanches have a finite extension in time, which is much smaller than the…