in this paper, a reliable approach is introduced to approximate periodic solutions of a system of coupled integrable dispersionless. the system is firstly, transformed into an ordinary differential equation by wave transformation. the solution of ode is obtained by the homotopy perturbation method. to show the periodic behavior of the solution, a modification based on the laplace transforms and...

the determination of soil wetting front which caused by emitters is one of the important issues in designing trickle irrigation system. in this study, a mathematical model introduced in order to study the position of soil wetting front during irrigation by point emitters in homegenious soil in unsteady condition. the model solves governing differential equation of unsaturated flow in cylindrica...