Table 1.

The coded values and actual values (uncoded) for independent variables

Independent variables	Parameters levels
	−$\mathit{\alpha }$	−1	0	+1	+ $\mathit{\alpha }$
Microwave power, w (x 1)	200	300	400	500	600
Irradiation time, min (x 1)	4	6	8	10	12
Acetone:H2O ratio, % (x 1)	0	25	50	75	100