Relative to $C_{eff}$

  $\displaystyle \frac{\partial Tcal}{\partial C_{eff}} =
\frac{Tcal}{C_{eff}} - \frac{Tcal}{T_{load}-T_{emi}}
\frac{\partial T_{emi}}{\partial C_{eff}}
$ (45)
  $\displaystyle \frac{\partial T_{emi}}{\partial C_{eff}} =
\frac{(T_{emi}+Trec)^2}{T_{load}+Trec}
$ (46)
  $\displaystyle \frac{1}{Tcal} \frac{\partial Tcal}{\partial C_{eff}} =
\frac{1}...
...} -
\frac{(T_{emi}+Trec)^2}{C_{eff}^2 * (T_{load}+Trec) * (T_{load}-T_{emi}) }
$ (47)