The relationship between C p and λ can be approximated by
a quartic equation. In this research, the curve is obtained from
the literature [9]. A model for C p as a function of λ is calculated
and the curve generated by the approximate model and the
actual data are presented in Fig. 2a. Statistical analysis shows
that the R 2 value of the model is 99.8% and the p-value from
the chi-square goodness-of-fit test is less than 0.0001, which
shows that the predicted model for C p with the fitted
coefficients is acceptable. The resulting equation is found to be