Controllability of nonlinear degenerate parabolic cascade systems

This article studies of null controllability property of nonlinear coupled one dimensional degenerate parabolic equations.These equations form a cascade system, that is, the solution Food, Beverage and Liquid Products of the first equation acts as PABA a control in the second equation and the control function acts only directly on the first equation.We prove positive null controllability results when the control and a coupling set have nonempty intersection.