Heat transfer equation

Hi!

I'm new to solving PDE in Mathcad but I need to solve heat transfer equation in the form as specified in the file. I thought that should be easy to use built-in function Pdesolve, but I guess I was wrong, cause I keep gettin some error messages. 

Anh elp will be appreciated.

(I guess the problem is with he boundary condition, but maybe there are more)