Bordeaux group

The first unambiguous observation of a Turing instability in any experimental system did not occur until 1990. That year, the Bordeaux group found convincing evidence for Turing patterns in an in vitro system, the CIMA reaction (see Sect. 1.4.9). The gap of almost 40 yr between Turing s theoretical prediction of diffusion-induced instabilities and the experimental realization of stationary chemical pattern was caused by two main factors. 

CHU de Bordeaux, Groupe Hospitaller Sud, Bordeaux, France e-mail syIvie.crauste-manciet u-bordeaux.fr sylvie.crauste-manciet chu-bordeaux.fr... 

The first step in the search procedure is to put into practice the result derived from nonequilibrium thermodynamics that oscillation is a possibility only in a system sufficiently far from equilibrium. In order to maintain a nonequilibrium state we utilize a tool long familiar to chemical engineers and adapted to the study of chemical oscillation by the Bordeaux group (Pacault et al., [15]), the continuous flow stirred tank reactor (cSTR). A schematic diagram of a stirred tank reactor is shown in Figure 1. 

Through a digest of the works completed by the Bordeaux group in this field since the first experiment in 1989, this chapter, which associates experiments and numerical simulations, is an illustration of these recent developments. We focus on Turing patterns stricto sensu, excluding nonisothermal systems, nonlinear diffusion, or other transport phenomena like convection. In the spirit of the original work, we also limit ourselves to stationary patterns, or to nonstationary patterns which are associated to a Turing instability. 

In 1990, De Kepper and colleagues in Bordeaux, working with an open unstirred gel reactor, observed the first experimental evidence for Turing structures in a chemical system, the chlorite-iodide-malonic acid (CIMA) reaction [4]. Since then this work has been verified and extended both by the Bordeaux group [11-13], and by Ouyang and Swinney [14] in Texas, using several different reactor configurations. 

Subclass 01, or simple parallel Such polymers were obtained first by Hessel and Finkelmann, later by Zhou and collaborators, and also by Keller et the Bordeaux group calls them side-... 

A comprehensive programme of synthesis and characterization by the Bordeaux group" has provided a wealth of comparative data on which Table 7.6 is based note that the polymers are well defined, monodisperse systems. The general points to emerge from these and comparable data are as follows ... 

Polysulfide Melt. Cl Sulfur Black 1 [1326-82-5] (Cl 53185), derived from 2,4-dinitrophenol, is the most important dye in this group which also includes the indophenol-type intermediates. The latter are appHed in the stable leuco form. The derived dyes are usually confined to violet, blue, and green shades. Other members of this group are intermediates capable of forming quinoneimine (10) or phenazone stmctures (11) that produce red-brown or Bordeaux shades ... 

Glories, Y. et al., Identification et dosage de la procyanidine A2 dans les raisin et les vins de Vitis vinifera L.C. V. merlot noir, cabernet sauvignon et cabernet franc. In Polyphenols Communications 96 (eds J. Vercauteren, C. Cheze, M. Dumon, and J.-F. Weber), Groupe Polyphenols, Bordeaux, 1996, p. 153. 

H. Fulcrand, P. J. Cameira dos Santos, P. Sami-Manchado, V. Cheynier, M. Moutounet. Polyphenols Communications. Groupe Polyphenols. Bordeaux, vol. 2, p. 259 (1996). 

Nanosciences and Catalysis Group, LCOO, UMR CNRS No. 5802, Universite Bordeaux I, 351 Cours de la Liberation, 33405 Talence Cedex, France d.astruc lcoo.u-bordeauxl.fr... 

Acknowledgements. The authors are indebted to Prof. P. Hagenmuller and Dr. J. Portier for their constant interest they took in this work. Profs. D. Babel, K. Hirakawa, D. Reinen, Drs. J. Darriet, G. Le Flem, R. Sabatier, and J. L. Soubeyroux are thanked for their helpful discussions and Mr. B. Ellis for his critical reading of the english language of the manuscript. The authors also wish to thank the members of the Fluorine Research Group in Bordeaux, especially Prof. J. Grannec and L. Lozano. 

Andres-Lacueva, C., Lamuela-Raventos, R. M., Buxadera, S., Torre-Bonat, M. C. (1996). Polyphenol content in sparkling wines (Cava) at different aging period. In J. Vercauteren, C. Cheze, M.C. Dumon, J.F. Weber (Eds.), Polyphenols communications 96/XVIIIth International Conference on Polyphenols (Vol. 2, pp. 305-306). Bordeaux Secretariat du Groupe Polyphenols. 

Functionally substituted benzylic, allylic, and vinylic compounds containing alkoxides, esters, ethers, nitriles, or amides can be reacted with halosilanes under Barbier conditions using HMPT to yield C- and O-silylated products, 1,2- or 1,4-addition products, as well as reductive dimers. Radical and anionic intermediates are postulated, based on SET reactions from the metal, and multiple silated species can be obtained. The use of the TMSCl-Mg-HMPT system has been extensively investigated by Galas group [85] at the University of Bordeaux, and their work has greatly advanced the science of the Barbier reaction with silanes. 

Thierry Toupance Institut des Sciences Mol6culaires, Groupe Materiaux, University of Bordeaux 1, Institut des Sciences Mol6culaires, France... 

University de Bordeaux, Institut des Sciences Moleculaires, Groupe Matdriaux, Talence Cedex, France... 

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