Gel permeation chromatography on polyelectrolytes in aqueous solution

Gel permeation chromatography of water-soluble polymers, with special attention to polyelectrolytes, has been studied. A three-detector system (refractometry, conductimetry, viscometry) is used to characterize the polymers. A single curve is obtained for the calibration of the set of columns taking into account the hydrodynamic volume of the solutes and using a 0.1 N salt solution as the eluent to screen electrostatic forces. The role of the low adsorption of dextran on silica gel is pointed out. The dependence of elution volume on polymer concentration is demonstrated and interpreted in terms of the screening length of the molecules.     

Studium der Eigenschwingungen eines zylindrischen Plasmas mit der Methode der finiten Elemente

The eigenmodes of a cylindrical homogeneous plasma may be calculated analytically. There are three classes of solutions. The eigenvalues of the first class are well separated, those of the second class have a point of accumulation. The eigenvalue of the third class is infinitely degenerated. The eigenvalues and eigenmodes of the corresponding discrete finite element problem tend towards the true solution. The convergence properties are discussed.     

ESR study of second stage nickel chloride graphite intercalation compound

The temperature dependences of g-factor and linewidth of C_11,3NiCl_2,13 single crystals have been measured from 10 to 400 K. The data indicate that nickel ions in graphite behave at low temperatures like Ising ions, with a phase transition occurring at about 30 K.     

Duality in generalized linear fractional programming

We consider a generalization of a linear fractional program where the maximum of finitely many linear ratios is to be minimized subject to linear constraints. For this Min-Max problem, a dual in the form of a Max-Min problem is introduced and duality relations are established.     

The Migratory Aptitude of the Ethoxycarbonyl Group in the Pinacol Rearrangement. Preliminary communication

The migratory aptitude of the ethoxycarbonyl group in the pinacol rearrangement was deduced from the structure of the products observed after treatment of 2-substituted 2,3-dihydroxy-3-phenylbutyrates with fluorosulfonic acid at 0° for 3 minutes. The migratory aptitude of ethoxycarbonyl is comparable to that of ethyl, greater than that of methyl or hydrogen, but smaller than that of phenyl. Cyclization and fragmentation reactions were also observed.     

The determination of the absolute configuration of tri-o-thymotide by crystal structure analysis and optical rotation.

The absolute configuration of tri-o-thymotide was obtained from the crystal structure of the solvate with (R)-2-butanol in association with optical measurements.     

Finite dimensional approximation of nonlinear problems

Summary We continue here the study of a general method of approximation of nonlinear equations in a Banach space yet considered in [2]. In this paper, we give fairly general approximation results for the solutions in a neighborhood of a simple limit point. We the apply the previous analysis to the study of Galerkin approximations for a class of variationally posed nonlinear problems and to a mixed finite element method for the NavierStokes equations.This work has been completed during a visit at the Université Pierre et Marie Curic and at the Ecole PolytechniqueSupported by the Fonds National Suisse de la Recherche Scientifique     

Derivation fonctionnelle abstraite

In this paper, the classical theory, due to R. de POSSEL [11][12], of abstract derivation basis with VITALI properties, is systematically generalized with a functional formulation. That is to say that the derivation by means of suitable families of measurable sets is replaced by a derivation using measurable functions. A theorem which gives various caracterizations of that functional basis of weak VITALI type includes a theorem obtained by R. de POSSEL [13] about this kind of derivation. This result leads to the introduction of VITALI conditions of functional type in a derivation theorem of N. DUNFORD and J. T. SCHWARTZ [3].