Mathematics

Permanent URI for this collectionhttp://197.211.34.35:4000/handle/123456789/100

Mathematics

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Subject: search.filters.subject.contaminant

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    The Pollutant Concentration Regime in a Flow due to Variable Time-Dependent Off-Diagonal Dispersion
    (AIJR Publisher, 2019-10-19) JIMOH, OMANANYI RAZAQ; Aiyesimi, Y. M.
    In this paper, an Eigen Functions expansion technique was used to obtain an analytical solution of twodimensional contaminant flow problem with non-zero initial concentration. The equation which describes the two-dimensional contaminant flow model is a partial differential equation characterized by advection, dispersion, adsorption, first order decay and zero-order source. It was assumed that the adsorption term was modeled by Freudlich isotherm. The off-diagonal dispersion parameter was incorporated into the two-dimensional contaminant model in order to expand the scope of the analysis. The model equation was non-dimensionalized before the parameter expanding method was applied. The resulting equations were solved successively by Eigen functions expansion technique. This research establishes that the pollutant concentration declines with increase in distances in both directions as the off-diagonal dispersion coefficient, zero-order source coefficient and vertical dispersion coefficient increases.
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    Agreement between the Homotopy Perturbation Method and Variation Iterational Method on the Analysis of One-Dimensional Flow Incorporating First Order Decay
    (SCHOOL OF PHYSICAL SCIENCES, FEDERAL UNIVERSITY OF TECHNOLOGY, MINNA, 2019-06-28) JIMOH, OMANANYI RAZAQ; Aiyesimi, Y. M.; Jiya, M.
    In this paper, a comparative study of reactive contaminant flow for constant initial concentration in one dimension is presented. The adsorption term is modeled by Freudlich Isotherm. An approximation of the one-dimensional contaminant flow model was obtained using homotopy-perturbation transformation and the resulting linear equations were solved semi-analytically by homotopyperturbation method (HPM) and Variational Iteration Method (VIM). Graphs were plotted using the solution obtained from the methods and the results presented and discussed. The analysis of the results obtained show that the concentration of the contaminant decreases with time and distance as it moves away from the origin.
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    INFLUENCE OF ZERO-ORDER SOURCE AND DECAY COEFFICIENTS ON THE CONCENTRATION OF CONTAMINANTS IN TWO-DIMENSIONAL CONTAMINANT FLOW
    (SCHOOL OF PHYSICAL SCIENCES, FEDERAL UNIVERSITY OF TECHNOLOGY, MINNA, 2017-04-23) JIMOH, OMANANYI RAZAQ; Aiyesimi, Y. M.; Jiya, M.; Bolarin, G. A.
    In this article, an eigenfunctions expansion method is used in studying the behavior of two-dimensional contaminant flow problem with non-zero initial concentration. The mathematical model describing the contaminant flow is described by advection, dispersion, adsorption, first order decay and zero-order source. It is assumed that the adsorption term is modeled by Freudlich isotherm. Before the application of the eigenfunctions method, the parameter expanding method is applied on the model and the boundary conditions are transformed to the homogeneous type. Thereafter, the approximate solution of the resulting initial value problem was obtained successively. The results obtained are expressed graphically to show the effect of change in the zero-order source and decay coefficients on the concentration of the contaminants. From the analysis of the results, it was discovered that the contaminant concentration decreases with increase in the distance from the origin as the zero-order source and decay coefficient increases.
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    Behaviour of Contaminant in a Flow due to Variations in the Cross-Flow dispersion under a Dirichlet Boundary Conditions.
    (SCHOOL OF PHYSICAL SCIENCES, FEDERAL UNIVERSITY OF TECHNOLOGY, MINNA, 2024-04-18) JIMOH, OMANANYI RAZAQ; Adebayo A.; Salihu, N. O.; Bako, D.
    The advection-dispersion equation (ADE) is mostly adopted in evaluating solute migration in a flow. This study presents the behavior of contaminant in a flow due to variations in the cross-flow dispersion under a Dirichlet boundary conditions. The analytical solution of a two-dimensional advection-dispersion equation for evaluating groundwater contamination in a homogeneous finite medium which is initially assumed not contaminant free was obtained. In deriving the model equation, it was assumed that there was a constant point-source concentration at the origin and a Dirichlet type boundary condition at the exit boundary. The cross-flow dispersion coefficients, velocities and decay terms are time-dependent. The modeled equation was transformed using some space and time variables and solved by parameter expanding and Eigen-functions expansion method. Graphs were plotted to study the behavior of the contaminant in the flow. The results showed that increase in the cross-flow coefficient decline the concentration of the contaminant with respect to increase in time, vertical distance and horizontal distance in different patterns.