## 3 Results and Discussions
### DoE Analysis Results
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Factors**} & \multirow{2}{*}{\
\begin{tabular}{c} **Degree of** \\ **Freedom** \\ **(DF)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Adjusted Sum** \\ **of Squares (SS)** \\ \end{tabular} } & \multicolumn{2}{c}{**Adjusted Mean**} & \multirow{2}{*}{\(F\) = MS/MS\({}_{\mathrm{E}}\)} & \multirow{2}{*}{\(p\)} & \multirow{2}{*}{**Contribution**} \\  & & & & & & \\ \hline \multicolumn{6}{c}{Linear Effects} \\ \hline A & 1 & 0.6641 & 0.6641 & 5.95 & 0.040 & 22.44\% \\ B & 1 & 0.4955 & 0.4955 & 4.44 & 0.068 & 16.74\% \\ C & 1 & 0.0491 & 0.0491 & 0.44 & 0.525 & 1.66\% \\ \hline \multicolumn{6}{c}{2-way Interactions} \\ \hline AB & 1 & 0.0347 & 0.0347 & 0.31 & 0.592 & 1.17\% \\ AC & 1 & 0.1001 & 0.1001 & 0.90 & 0.371 & 3.38\% \\ BC & 1 & 0.7230 & 0.7230 & 6.48 & 0.034 & 24.43\% \\ Error & 8 & 0.8931 & MS\({}_{\mathrm{E}}\) = 0.111 & - & - & 30.18\% \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Analysis of variance for \(I_{\mathrm{2D}}/I_{\mathrm{G}}\) using adjusted SS for the tests. The texts marked in red represent statistically-significant terms. Figure 3: Interaction plots of the factors “A”, “B” and “C” for Response I (**a**) and Response II (**b**); solid circles indicate the interaction points. Factor interaction terms “AB” and “AC” are visible for Response I, while factor interaction terms “AC” and “BC” are visible for Response II. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Factors**} & \multirow{2}{*}{\
\begin{tabular}{c} **Degrees of** \\ **Freedom** \\ **(DF)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Adjusted Sum** \\ **of Squares (SS)** \\ \end{tabular} } & \multicolumn{2}{c}{**Adjusted Mean**} & \multirow{2}{*}{\(F\) = MS/MS\({}_{\mathrm{E}}\)} & \multirow{2}{*}{\(p\)} & \multirow{2}{*}{**Contribution**} \\  & & & & & & \\ \hline \multicolumn{6}{c}{Linear Effects} \\ \hline A & 1 & 0.0495 & 0.0495 & 0.65 & 0.445 & 7.46\% \\ B & 1 & 0.0067 & 0.0067 & 0.09 & 0.775 & 1.01\% \\ C & 1 & 0.0618 & 0.0618 & 0.80 & 0.396 & 9.31\% \\ \hline \multicolumn{6}{c}{2-way Interactions} \\ \hline AB & 1 & 0.3599 & 0.3599 & 4.69 & 0.062 & 54.28\% \\ AC & 1 & 0.1174 & 0.1174 & 1.53 & 0.251 & 17.70\% \\ BC & 1 & 0.0066 & 0.0066 & 0.086 & 0.776 & 0.99\% \\ Error & 8 & 0.6142 & MS\({}_{\mathrm{E}}\) = 0.076 & - & - & 9.26\% \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Analysis of variance for \(I_{\mathrm{D}}/I_{\mathrm{G}}\) using adjusted SS (Sum of Squares) for the tests. The text marked in red represents the statistically-significant term. Table 3 indicates that the factors' interaction \"AB\" is the only statistically-significant term for Response I at the 10% significance level as the \"\(p\)\" value is less than 0.1. The presence of the main effect of the factors \"A\", \"B\", \"C\" and the factors' interaction term \"AC\" for Response I, as depicted by the plots in Figures 2 and 3, respectively, are all found to be statistically insignificant. Table 4 indicates that the main effect of the factors \"A\" and \"B\" along with the factors' interaction term \"BC\" are all statistically-significance for the response II at the 10% significant level, as the \"\(p\)\" value is less than 0.1. The presence of the main effect of the factor \"C\" and the factors' interaction term \"AC\" for Response II, as depicted by the plots in Figures 2 and 3, respectively, are all statistically insignificant. The interaction term \"BC\" is the most significant in affecting Response II, followed by the factor \"A\" and the factor \"B\".