| dc.creator |
Lehr, Heiner |
|
| dc.creator |
Sagués i Mestre, Francesc |
|
| dc.creator |
Sancho, José M. |
|
| dc.date |
2011-07-07T12:50:51Z |
|
| dc.date |
2011-07-07T12:50:51Z |
|
| dc.date |
1996 |
|
| dc.date.accessioned |
2024-12-16T10:27:18Z |
|
| dc.date.available |
2024-12-16T10:27:18Z |
|
| dc.identifier |
1539-3755 |
|
| dc.identifier |
http://hdl.handle.net/2445/18700 |
|
| dc.identifier |
114548 |
|
| dc.identifier.uri |
http://fima-docencia.ub.edu:8080/xmlui/handle/123456789/22225 |
|
| dc.description |
In this paper we consider diffusion of a passive substance C in a temporarily and spatially inhomogeneous two-dimensional medium. As a realization for the latter we choose a phase-separating medium consisting of two substances A and B, whose dynamics is determined by the Cahn-Hilliard equation. Assuming different diffusion coefficients of C in A and B, we find that the variance of the distribution function of the said substance grows less than linearly in time. We derive a simple identity for the variance using a probabilistic ansatz and are then able to identify the interface between A and B as the main cause for this nonlinear dependence. We argue that, finally, for very large times the here temporarily dependent diffusion "constant" goes like t-1/3 to a constant asymptotic value D¿. The latter is calculated approximately by employing the effective-medium approximation and by fitting the simulation data to the said time dependence. |
|
| dc.format |
9 p. |
|
| dc.format |
application/pdf |
|
| dc.language |
eng |
|
| dc.publisher |
The American Physical Society |
|
| dc.relation |
Reproducció del document publicat a: http://dx.doi.org/10.1103/PhysRevE.54.5028 |
|
| dc.relation |
Physical Review e, 1996, vol. 54, num. 5, p. 5028-5036 |
|
| dc.relation |
http://dx.doi.org/10.1103/PhysRevE.54.5028 |
|
| dc.rights |
(c) The American Physical Society, 1996 |
|
| dc.rights |
info:eu-repo/semantics/openAccess |
|
| dc.source |
Articles publicats en revistes (Física Quàntica i Astrofísica) |
|
| dc.subject |
Òptica geomètrica |
|
| dc.subject |
Materials inhomogenis |
|
| dc.subject |
Geometrical optics |
|
| dc.subject |
Inhomogeneous materials |
|
| dc.title |
Diffusion in spatially and temporarily inhomogeneous media |
|
| dc.type |
info:eu-repo/semantics/article |
|
| dc.type |
info:eu-repo/semantics/publishedVersion |
|