Generalized Fractal Kinetics in Complex Systems (Application to Biophysics and Biothechnology)

We derive a universal function for the kinetics of complex systems. This kinetic function unifies and generalizes previous theoretical attempts to describe what has been called "fractal kinetic".The concentration evolutionary equation is formally similar to the relaxation function obtained in the stochastic theory of relaxation, with two exponents a and n. The first one is due to memory effects and short-range correlations and the second one finds its origin in the long-range correlations and geometrical frustrations which give rise to ageing behavior. These effects can be formally handled by introducing adequate probability distributions for the rate coefficient. We show that the distribution of rate coefficients is the consequence of local variations of the free energy (energy landscape) appearing in the exponent of the Arrhenius formula. We discuss briefly the relation of the (n,a) kinetic formalism with the Tsallis theory of nonextensive systems.Comment: 15 pages, 3 figures, submitted to Physica

Vanishing Loss Effect on the Effective ac Conductivity behavior for 2D Composite Metal-Dielectric Films At The Percolation Threshold

We study the imaginary part of the effective $ac$ conductivity as well as its distribution probability for vanishing losses in 2D composites. This investigation showed that the effective medium theory provides only informations about the average conductivity, while its fluctuations which correspond to the field energy in this limit are neglected by this theory.Comment: 6 pages, 2 figures, submitted to Phys.Rev.

Local spin-susceptibility in disordered alloys II

We explore the analogy between a new formulation of the problem of local susceptibility in concentrated alloys and the theory of localization of electronic states in disordered systems. This discussion opens the way to a better description and understanding of the effect of local magnetic properties in disordered systems. In particular, the effect of cluster-cluster interactions and the nature of the magnetic-non magnetic phase transition in alloys is considered. Finally, we discuss the possibility in concentrated alloys of a cluster generalization of the spin glass phase

Non linear modelisation of dyes removal from aqueous solution by using sorption onto Luffa cylindrica fibers

The biosorption of indigo carmine (IC) and methylene blue (MB) using a lingo-cellulosic fiber: Luffa cylindrical was carried out in this study. It was shown in this work, that biosorption capacity of dyes increase with increase of initial dyes concentrations and mass of biomass and to decrease with the raise of salt and temperature. Optimal parameters of the biosorption of dyes onto Luffa cylindrica were obtained after 150 min and pH 10 for MB and 525 min and pH 2 for IC. The experimental equilibrium data were studied employing the isotherms of Langmuir, Freundlich, Jovanovic, Temkin, Redlich–Peterson, Toth, Sips, and Brouers–Sotolongo. The experimental data fitted very well with the Bouers-Sotolongo isotherm for MB and the Toth isotherm for IC. Concerning IC, the value of maximum biosorption capacity (Qm = 6.876 mg/g) was close to the experimental value (Qm = 6.874 mg/g), and the correlation coefficient (R2) was 0.996. While for MB, the value of maximum biosorption capacity (Qm = 13.849 mg/g) was close to the experimental value (Qm = 13.900 mg/g), and the correlation coefficient (R2) was 0.992. In order to study the biosorption kinetics, four kinetics models such as pseudo-first order, pseudo-second order, Elovich and Brouers-Sotolongo were studied. The Brouers-Sotolongo (2,α) fractal  model appears to be the best model to fit the experimental data.