Liquid–solid interaction at nanoscale and its application in vegetal biology
Event details
| Date | 06.12.2011 |
| Hour | 17:15 |
| Speaker | Prof. Henri Gouin, Université Aix-Marseille, C.N.R.S, France |
| Location |
MEB 331
|
| Category | Conferences - Seminars |
The water ascent in tall trees is subject to controversy: the vegetal
biologists debate on the validity of the cohesion–tension theory which
considers strong negative pressures in microtubes of xylem carrying the
crude sap. This work aims to point out that liquids are submitted at the
walls to intermolecular forces inferring density gradients making
heterogeneous liquid layers and therefore disqualifying the Navier–
Stokes equations for nanofilms. The crude sap motion takes the
disjoining pressure gradient into account and the sap flow dramatically
increases such that the watering of nanolayers may be analogous to a
microscopic flow. Application to microtubes of xylem avoids the problem
of cavitation and enables us to understand why the ascent of sap is
possible for very high trees.
Practical information
- General public
- Free
Contact
- Mohamed FARHAT