Table 3 Representations of independent variables and their levels with values of standard deviation.
Factors | Independent Variables | Units | Coded Low | Coded High | Std. Deviation |
|---|---|---|---|---|---|
A | Leachant Concentration | mol/L | −1↔0.75 | + 1↔2.00 | 0.53 |
B | Reaction Temperature | K | −1↔298.00 | + 1↔343.00 | 19.08 |
C | Leaching Time | minutes | −1↔90.00 | + 1↔240.00 | 63.59 |
