highly significantp < 0.0001
The quadratic terms (A 2 , B 2 , C 2 , D 2 ) and interaction terms (AB, AC, BD, CD) were highly significant ( p < 0.0001), while BC was significant at the p < 0.01 level ( Table 5 ).
The quadratic terms (A 2 , B 2 , C 2 , D 2 ) and interaction terms (AB, AC, BD, CD) were highly significant ( p < 0.0001), while BC was significant at the p < 0.01 level ( Table 5 ).
The comprehensive score demonstrated a clear trend, initially increasing and then decreasing as the ultrasonic temperature rose from 40 to 60 °C, the ultrasound time extended from 40 to 80 min, the ethanol concentration increased from 50% to 70%, and the solid-to-liquid ratio expanded from 30:1 to 50:1 ( Figure 3 a–f).