Model No.

Model expression

Regression coefficient R²

1

ε_B = −432953 − 20571.98D + 99964.86D_c + 104839.34D_f

0.956

2

ε_B = −115184 + 46204D_f

0.790

3

ε_B = −333868 + 104099D + 28508D_f

0.998

4

R_B = 59 + 22.55D − 26.96D_c − 21.19D_f

0.940