Related Experiment Video
Updated: Apr 21, 2026
08:01
The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
9.8K
Superdiffusion and transport in two-dimensional systems with Lévy-like quenched disorder
Raffaella Burioni1, Enrico Ubaldi2, Alessandro Vezzani3
1Dipartimento di Fisica e Scienza della Terra, Università di Parma, viale G.P. Usberti 7/A, 43124 Parma, Italy and INFN, Gruppo Collegato di Parma, viale G.P. Usberti 7/A, 43124 Parma, Italy.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|October 30, 2014
Summary
We analyzed transport in superdiffusive 2D random media packed with disks following a Lévy distribution. An effective Lévy exponent was defined to predict finite-size effects and identify superdiffusion regions.
Area of Science:
- Physics
- Materials Science
Background:
- Superdiffusion in disordered systems is crucial for understanding anomalous transport phenomena.
- Quenched random media, particularly those with Lévy-distributed particle sizes, exhibit complex transport behaviors.
Purpose of the Study:
- To analyze transport and scaling properties in two-dimensional (2D) quenched random media with Lévy-distributed disk radii.
- To investigate the influence of different packing procedures (fixed filling fraction vs. self-similar packing) on superdiffusive effects.
- To define an effective Lévy exponent for characterizing finite-size effects and superdiffusion.
Main Methods:
- Packing disks with radii distributed according to a Lévy law to create 2D quenched random media.
- Analyzing transport and scaling properties under fixed filling fraction and self-similar packing conditions.
- Utilizing the filling fraction in finite-size systems as a key geometrical parameter.
Main Results:
- The study clarifies the distinct roles of fixed filling fraction and self-similar packing procedures in superdiffusive effects.
- An effective Lévy exponent was defined, accurately estimating finite-size effects.
- This exponent governs the dynamical scaling of transport properties and identifies superdiffusion regimes.
Conclusions:
- The effective Lévy exponent is a critical parameter for understanding and predicting superdiffusion in these systems.
- The findings provide a framework for analyzing transport properties in complex disordered media.
- This research contributes to the fundamental understanding of anomalous transport in quenched random environments.
More Related Videos
Related Concept Videos
01:21Carrier Transport
1.1K
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
1.1K
01:24Protein Diffusion in the Membrane
4.7K
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
4.7K
01:21Diffusion
5.6K
Diffusion is a type of passive transport. In passive transport, a substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across the space. For example, take the diffusion of substances through the air. When someone opens a perfume bottle in a room filled with people, the perfume is at its highest concentration in the bottle and is at its lowest at the edges of the room. The perfume vapor will diffuse, or spread away, from the...
5.6K
01:12Diffusion
176.2K
Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall...
176.2K
01:18First Law: Particles in Two-dimensional Equilibrium
14.2K
Recall that a particle in equilibrium is one for which the external forces are balanced. Static equilibrium involves objects at rest, and dynamic equilibrium involves objects in motion without acceleration; but it is important to remember that these conditions are relative. For instance, an object may be at rest when viewed from one frame of reference, but that same object would appear to be in motion when viewed by someone moving at a constant velocity.
Newton's first law tells us about...
Newton's first law tells us about...
14.2K
01:10First Law: Particles in One-dimensional Equilibrium
6.7K
Newton's first law of motion states that a body at rest remains at rest, or if in motion, remains in motion at constant velocity, unless acted on by a net external force. It also states that there must be a cause for any change in velocity (a change in either magnitude or direction) to occur. This cause is a net external force. For example, consider what happens to an object sliding along a rough horizontal surface. The object quickly grinds to a halt, due to the net force of friction. If...
6.7K