Tetronics/cyclodextrin-based hydrogels as catalyst-containing media for the hydroformylation of higher olefins

International audienceno abstrac

3D rotational diffusion of micrometric wires using 2D video microscopy

We propose a simple way to measure the three-dimensional rotational diffusion of micrometric wires, using two-dimensional video microscopy. The out-of-plane Brownian motion of the wires in a viscous fluid is deduced from their projection on the focal plane of an optical microscope objective. An angular variable reflecting the out-of-plane motion, and satisfying a Langevin equation, is computed from the apparent wire length and its projected angular displacement. The rotational diffusion coefficient of wires between 1 and 100 μm is extracted, as well as the diameter distribution. Translational and rotational diffusion were found to be in good agreement. This is a promising way to characterize soft visco-elastic materials, and probe the dimension of anisotropic objects

Métallo-Carbènes : Apoptose et arrêt du Cycle Cellulaire

Communication oral

3D rotational diffusion of micrometric wires using 2D video microscopy

We propose a simple way to perform three-dimensional (3D) rotational microrheology using two-dimensional (2D) video microscopy. The 3D rotational brownian motion of micrometric wires in a viscous fluid is deduced from their projection on the focal plane of an optical microscope objective. The rotational diffusion coefficient of the wires of length between 1-100 \mu m is extracted, as well as their diameter distribution in good agreement with electron microscopy measurements. This is a promising way to characterize soft visco-elastic materials, and probe the dimensions of anisotropic objects.Comment: 10 pages, 7 Figures, accepted for publication in EP

The Ring Imaging Cherenkov Detectors of DELPHI.

A Ring Imaging Cherenkov (RICH) detector system has been built and is now in full operation within the DELPHI experiment. Large data samples of Z0 decays are being collected with good resolution on the observed Cherenkov angles. Several studies of Z0 decays using the RICH have already been performed on limited samples. Disturbance of the detector operation caused by shrinkage of polymeric construction materials and by migration of radiator substance is reported. These effects have been counteracted and do not endanger the quality of the data. © 1995 IEEE