## 3 Results and Discussion  
* The physical properties The physical characteristics of the samples of black poplar with different impregnation methods are presented in Table 3. Using the ANOVA test, it was found that there was a statistically significant difference between the control and impregnated sample sets in terms of the physical characteristics of the experimental specimens. After applying the Duncan test, four homogeneous clusters were delineated within each of the datasets corresponding to D\({}_{0}\), TS-2, and TS-24 h and five homogeneous clusters were delineated within each of the datasets corresponding to WA-2, WA-24, and WPG. It was found that the density (D\({}_{0}\)) and weight percent gain (WPG) rose when the lime ratio increased in the two impregnation methods. When 1%, 3%, and 5% lime were added, respectively, the D\({}_{0}\) values were found to be between 0.41 and 0.49 g/cm\({}^{3}\). Depending on this, the WPG increased between 0.62% and 2.28%. Applied impregnation methods with lime progressively decreased water absorption and thickness swelling in the samples. It was observed that WA-2, WA-24, TS-2, and TS-24 values decreased when 1%, 3%, and 5% lime were added, respectively. The WA-2 decreased between 11.5% and 30.5%, the WA-24 values decreased between 6.9% and 18.4%, the TS-2 values decreased between 10.9% and 27.6%, and the TS-24 values decreased between 12.6% and 29.7% in the immersion method. In the vacuum method, which is the other method applied, the WA-2 decreased between 18.2% and 42.2%, WA-24 values decreased between 12.3% and 25.7%, TS-2 values decreased between 22.6% and 40.5%, and TS-24 values decreased between 13.9% and 33.6% (Table 3). These data are consistent with earlier research, which found that adding lime to wood increased its physical qualities and made it more stable dimensionally [5; 8; 9; 33]. In addition, there appear to be obvious differences in physical properties between the applied methods. It is seen that the vacuum method provides more stability to the wood material compared to the immersion method [51; 52; 53]. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Sample Type** & **D\({}_{0}\) (g/cm\({}^{3}\))** & **WA-2 h** & **WA-24 h** & **TS-2 h** & **TS-24 h** & **WPG (\%)** \\ \hline A & 0.36 (0.09) 1 a 2 & 38.21 (3.57) a & 72.89 (5.88) a & 14.86 (2.43) a & 17.26 (3.45) a & - \\ B & 0.41 (0.13) b & 33.83 (3.26) b & 67.86 (6.11) b & 13.23 (1.31) b & 15.08 (3.04) b & 0.62 (0.09) a \\ C & 0.44 (0.09) c & 29.42 (2.61) c & 63.22 (5.67) c & 11.38 (1.14) c & 13.77 (2.14) c & 0.73 (0.21) b \\ D & 0.45 (0.11) c & 26.55 (1.93) d & 59.49 (4.93) d & 10.75 (0.81) c & 12.13 (1.86) d & 0.91 (0.18) b \\ E & 0.42 (0.12) b & 31.26 (2.79) c & 63.92 (4.55) c & 11.49 (1.05) c & 14.86 (2.11) b & 1.12 (0.30) c \\ F & 0.46 (0.14) c & 24.12 (2.44) d & 58.32 (5.22) d & 9.08 (1.27) d & 12.22 (1.37) cd & 1.79 (0.35) d \\ G & 0.49 (0.09) d & 22.07 (1.66) e & 54.11 (4.83) e & 8.83 (0.95) d & 11.45 (1.96) d & 2.28 (0.51) e \\ \hline \hline \end{tabular}  
* Standard deviation, 2: The same letters in a column of D0, WA-2, WA-24, TS-2, TS-24, and WPG are not significantly different (\(p\leq 0.01\)). The post hoc tests (Duncan) for the D0, WA-2, WA-24, TS-2, TS-24, and WPG were analyzed separately because the interaction factor was significantly different.  
\end{table} 
Table 3: The physical properties of impregnated wood samples. * The surface roughness, contact angle, and LOI properties  
Table 4 displays the surface roughness, contact angle, and LOI characteristics of samples of black poplar treated with various impregnation methods. According to the ANOVA test, a statistically significant difference was detected in the physical properties of both control and impregnated sample groups. Following the implementation of the Duncan test, we identified four consistent and similar groups within each dataset associated with surface roughness, contact angle, and LOI. The average roughness parameter (Ra) increased with an increase in the solution ratio.