pm_me_a_pokemon

What is your favorite math solving software? Specifically for solving multiple differential equations.

programs like matlab, polymath, mathmatica..

Great idea IJTreasure. I just graduated from a ChemE program, and let me tell you there are endless ways to use math in the science field. Sticking with a dual degree in math will be a very challenging work load, but the two fields overlap continuously. The hardest part I think is seeing complex math with real life variables other than 'x' or 'y' (temperature, enthalpy, pressure). most of the difficult math in ChemE ends up being differential equations and minor calculus.

in research, there are always new correlations being proposed for separation or reaction systems. A lot of diffusion models are simply that, theoretical models. Continuous research creates new equations for sizing of equipment or determining the diffusion coefficients for certain applications. It is very difficult work, and requires a very good knowledge of math, something I won't attempt to achieve. An example of this real life model is a dialysis cartridge, the thing hospitals use to filter your blood as an artificial kidney. There are models to estimate the diffusion coefficient based on the geometry of equipment such as this. Good luck!