(recherche/a3t2/a3t2a1/plus.htm)Membranes, mousses et mouillage

Flowing foams: in two dimensions, mechanical measurements and imaging are simultaneously possible

Film1 (mpg - 1.6Mo): A foam flows past a round obstacle (the "Stokes experiment" revisited in 2 dimensions)...	Film2 (mpg - 2Mo): ...or through a tiny hole. In collaboration with Notre-Dame, Bloomington, Los Alamos (USA) and CEA (Grenoble). Films by M. Asipauskas.
Film3 (avi - 11Mo): A Langmuir foam (one molecule thick) sheared by a moving obstacle In collaboration with Univ. Paris VI (France). Film by S. Courty.
Film4 (mov - 12Mo): 2D flow of foam around a circular obstacle (diameter 3 cm) at low flow rate (velocity: 0.8 mm/s).	Film5 (mov - 12Mo): 2D flow of foam around a circular obstacle (diameter 3 cm) at moderate flow rate (velocity: 0.5 cm/s).
Film6 (mov - 12Mo): 2D flow of foam around a circular obstacle (diameter 3 cm) at high flow rate (velocity: 2.5 cm/s).
Film (mov - 10Mo): 2D flow of foam around an airfoil (Joukovski profile). Film by B. Dollet
Film6 (avi - 22Mo): Bubbles colored according to the number of sides: blue=7, red=5 Film by M. Asipauskas
T1artif1 (avi - 2.9Mo):A magnetic foam can easily be manipulated. Here, a small change in the magnetic field (using a simple needle, moved by our hand, barely visible as a shadow at the beginning of the movie) helps deformed bubbles rearrange and find a more stable configuration. Film by F. Elias.	T1artif2 (avi - 3.7Mo):The reverse manipulation, from the most stable to the initial metastable one, requires more effort from the experimentalist. We can iterate many times, always falling back on the same equilibrium states. Film by F. Elias.
Film7 (avi - 34Mo):If we start from a very deformed foam, our needle triggers a cascade of rearrangements. Film by F. Elias.

Imaging in 3 dimensions: it's a challenge!


Image1 (tif - 0.1Mo): A 3D image of a wet foam, obtained by X-ray tomography: 1000 pictures taken at different angles are enough to reconstruct exactly the whole 3D information	Image2 (png - 1,3Mo)
Film8 (mov - 1.8Mo): Time sequence showing the ageing of a dry foam. Shown are projections....	Film9 (mov - 7.7Mo): ... and cuts of complete 3D images Images by P. Cloetens In collaboration with ESRF Grenoble (France), Univ. Rennes (France), Univ. Bloomington (USA)