Publications

We consider homogeneous states of quantum multicomponent plasmas described by a spin-independent Hamiltonian. Using generalized-moment inequalities we show that the relation between the response and the correlation functions of the spin magnetic moments approaches the classical one in the infinite-wavelength limit (k-->0). For small k, the first correction is of order k2 and is bounded by the semiclassical correction.

The temperature dependence of the critical current density at high temperatures and in weak applied magnetic field for YBa2Cu3O7-y ceramic samples with a pronounced granular character is analyzed. The experimental results can be explained in terms of thermally activated motion of the intergrain Josephson vortices at grain boundaries, which may be an indication that the actual limiting factor for the critical current density in ceramic samples results from a weak pinning force density for the intergrain vortices rather than from the weak-link quenching.

The distribution function of precipitated particles in relation to their volume is modelled by a function reproducing the three moments of the real function. The time evolution of the distribution is simulated by the numerical solving of a non-linear differential equation system for the moments, resulting from the rate equation which describes the growth of the particles.

A method of the determination of the concentration of the Medasol type hydrolized and non-hydrolized polyacrylamide in aqueous solution by higy resolution MNR is presented. The method may be applied to dilute solutions under the conditions presented in this paper.

The microstructure modifications have been studied during the electroformation of positive and negative plates which give information regarding the optimal conditions for the obtaining of plates for lead batteries. The microstructure proved to depend on the conditions under which the electroformation takes place and on the nature of the electrolyte additions. The SEM studies showed that in the positive active mass, the particles are heterogeneously scattered and that they consist of amorphous and crystalline areas.