The interaction of p-sulphonatocalix [6] arene towards L-arginine and L-lysine has been studied inacidic aqueous solution (p1-1 2) using UV-Vis spectrophotometric titration technique. The psulphonatocalix[6] arene was found to be able to form 1:1 complexe with amino acids in water.The values of the association constant were determined at different temperatures to evaluate thethermodynamic funct...

Let G be a simple graph with n vertices. The coloring complex ∆(G) was defined by Steingrı́msson, and the homology of ∆(G) was shown to be nonzero only in dimension n − 3 by Jonsson. Hanlon recently showed that the Eulerian idempotents provide a decomposition of the homology group Hn−3(∆(G)) where the dimension of the j component in the decomposition, H n−3(∆(G)), equals the absolute value of th...

Résumé. Nous introduisons une famille de conditions aux limites absorbantes pour des équations paraboliques à coefficients variables et une frontière quelconque. Elle repose sur l’identification géométrique de l’application Dirichlet à Neumann, et une approximation rationelle de z 1/2 dans le plan complexe. Les conditions aux limites obtenues sont stables, précises, et faciles à mettre en œuvre.