Hi. I am trying to simulate this paper since apparently I have a lot of time. Scrolling down to the last page, he simulated a transient 2D heat conduction plate with composite slabs on it. Darkest one is copper, lighter one is steel, lightest one is glass. If you look closely, the authors said they maintained two sides at 100OC and the other remaining sides at 50OC. Note that the plate was initially at 0OC. My question is, judging the diagrams they made - how did they do this? My hypothesis is that the boundary is varying with time, yes? So does that mean that the boundary conditions are functions with respect to time? Or am I missing something here; that my finite differencing is wrong? Currently my finite difference is setting the boundaries at 100 and 50, so at any time t the boundaries are 100 and 50.