11. Green's functions are also useful tools in solving wave equations and diffusion equations . 12. An example of results of solving the drift diffusion equation is shown on the right. 13. See also convection-diffusion equation . 14. Since this is the solution to the heat diffusion equation , this makes perfect sense intuitively. 15. If heat is transported by conduction, the heat flow is governed by a diffusion equation . 16. The BPM has been applied to problems such as nonhomogeneous Helmholtz and convection-diffusion equation . 17. It is known in mathematics as the diffusion equation , and has many analogs in other fields. 18. When Fick proposed the diffusion equation , the Gauss divergence theorem had been already reported in 1840. 19. The governing equation of the physics of the problem to be analyzed is the heat diffusion equation . 20. Next, using the convection diffusion equation an equation is obtained from the differentiation of this equation.