Transport
\(
\begin{eqnarray}
\frac{D T}{D t}&=&\frac{\pd }{\pd z} (\kappa \frac{\pd T}{\pd z}) +\hat{Q},\label{tr1}\\
\kappa \frac{\pd T}{\pd z} &=& \hat{T}, \mbox{ at } z=\eta, \label{tr2} \\
\kappa \frac{\pd T}{\pd z} &=& \hat{T_b}, \mbox{ at } z=-h, \label{tr3}
\end{eqnarray}
\)
