Update README.md

README.md

@@ -14,7 +14,7 @@ The main module is the script **Bioreactor.py**, while **ode_system_Forward_Eule
 
 **Bioreactor.py** solves the 1D advection-diffusion time equations for the biomass M (consisting of the _C. autoethanogenum_ biocatalyst), as wel as for the substrate feeding the biomass (CO), and the fermentation products such as acetate and ethanol. The general advection-diffusion equation for a variable X possibly function f of other Y variables, is 
 
- <img src="https://latex.codecogs.com/svg.latex?\small&space;\frac{\partial X}{\partial t}=\nu\frac{\partial^2 M}{\partial z^2}-c\frac{\partial X}{\partial z}+f(Y_1, Y_2, \dots, Y_n)" title="\small \frac{\partial X}{\partial t}=\nu\frac{\partial^2 X}{\partial z^2}-c\frac{\partial X}{\partial z}+ f(Y_1, Y_2, \dots, Y_n)" />
+ <img src="https://latex.codecogs.com/svg.latex?\small&space;\frac{\partial X}{\partial t}=\nu\frac{\partial^2 X}{\partial z^2}-c\frac{\partial X}{\partial z}+f(X, Y_1, Y_2, \dots, Y_n)" title="\small \frac{\partial X}{\partial t}=\nu\frac{\partial^2 X}{\partial z^2}-c\frac{\partial X}{\partial z}+ f(X, _1, Y_2, \dots, Y_n)" />
 
 as documented in [P. Lecca, A. Re 2020](https://link.springer.com/chapter/10.1007%2F978-3-030-63061-4_27).