We study solute dispersion in channels with periodically varying apertures. Based on an approximate analytical solution of the flow equation, we study the impact of the geometry and molecular diffusion on effective solute dispersion analytically using the method of local moments. We also study the problem numerically using a random walk particle tracking method. For transport in parallel shear ...

Abstract Dispersivity is a measurable parameter in soil porous media that used for studying the transport of contaminants to groundwater. The value this depends on various factors, including kind (homogeneous or heterogeneous), flow velocity, initial contaminant concentration, travel distance, and sampling method. A physical model with dimensions 0.10 m width, 0.80 height, 1.10 length was const...

The previously developed dispersion activity coefficient model (ACM) is extended from a molecular to group contribution (GC) providing results of equal accuracy as the model. Contrary other GC-ACMs presented GC-ACM preserves topology information each molecule in mixture. Therefore, contrast DISQUAC, UNIFAC or COSMOSAC, where eliminated by assignment groups construction sigma-profiles, this new ...

Abstract Determination of the longitudinal dispersion coefficient (LDC) is fundamental to development strategies for environmental management river systems. This paper presents an integrated model estimation by a fusion optimized intelligent models (optimized neural network (ONN), fuzzy inference system (OFIS), and support vector regression (OSVR)) via committee machine (CM), with optimization ...

Although dimensional analysis suggests sound functional forms (FFs) to calculate longitudinal dispersion coefficient (Kx), no attempt has been made quantify both reliability of the estimated Kx value and its sensitivity variation FFs' parameters. This paper introduces a new index named bandwidths similarity factor (bws–factor) FFs based on rigorous distinct calibration datasets tune FFs. We mod...

In the present era, the importance and role of green space in the life and development of cities are to the extent that it is mentioned as one of the indicators of sustainable development. In sustainable urban development, proportional distribution of green space according to the balanced distribution of the population is one of the principles of establishing geographical justice. The purpose o...