In the present study, analytical solutions are developed for three-dimensional advection-dispersion equation (ADE) in semi-infinite adsorbing saturated homogeneous porous medium with time dependent dispersion coefficient. It means porosity of the medium is filled with single fluid(water). Dispersion coefficient is considered proportional to seepage velocity while adsorption coefficient inversel...

In the present study, analytical solutions are developed for three-dimensional advection-dispersion equation (ADE) in semi-infinite adsorbing saturated homogeneous porous medium with time dependent dispersion coefficient. It means porosity of the medium is filled with single fluid(water). Dispersion coefficient is considered proportional to seepage velocity while adsorption coefficient inversel...

We investigate bright and dark solitons with anomalous or normal dispersion and under transverse harmonic confinement. In matter waves, positive atomic mass implies anomalous dispersion (kinetic spreading) while negative mass gives normal dispersion (kinetic shrinking). We find that, contrary to the strictly onedimensional case, the axial and transverse profiles of these solitons crucially depe...

When analyses of mixtures of small molecules are carried out at mobile phase velocities close to (for isocratic runs) or somewhat above (for gradient runs) the optimum velocity, the eddy diffusion term contributes to at least 75% of the band broadening. Future improvements in column performance may come only from a reduction of the eddy diffusion term. The classical models of axial dispersion o...

The paper is devoted to the parameter identification of the axial dispersion model in the closed–open canal. It is oriented to the identification precision for the two variants of the flow model with various variance levels. The identification method is based on the transfer function application for the solution of given model PDE. When the impulse function g(t) is obtained, the characteristics...

The reduction of nitrogen oxides (NOx) emissions from an existing burner is a a challenging task requiring the understanding of interactions between burner geometry and flame aerodynamics. Currently, three approaches for NOx control exist: fuel or flue gas treatment and combustion modifications. Low NOx burner design is economically attractive for natural gas and light fuel oil combustion since...

Longitudinal dispersion coefficient is a key variable for the description of the longitudinal transport in a river. In recent years, Artificial Neural Networks (ANNs) have become popular and useful tools for environmental modellers as they are perceived to overcome some of the difficulties associated with traditional statistical approaches. In these applications, however, little attention was g...

This paper presents the support vector machine approach to predict the longitudinal dispersion coefficients in natural rivers. Collected published data from the literature for the dispersion coefficient for wide range of flow conditions are used for the development and testing of the proposed method. The proposed SVM approach produce satisfactory results with coefficient of determination=0.9025...

The paper presents an analytical solution for dispersion of a solute in the peristaltic motion of a micropolar fluid in the presence of both homogeneous and heterogeneous chemical reactions. The average effective dispersion coefficient has been found using Taylor’s limiting condition under long wavelength approximation. The effects of various relevant parameters on the average coefficient of di...

Although slow conduction is a requirement for the preparation of sustained reentry, it alone is not sufficient for the initiation of reentry. Additionally, unidirectional block and recovery of excitability distal to the site of block must occur. Thus, a comprehensive description of the electrophysiological determinants of reentry must explain both slow conduction and unidirectional block. Altho...