Table 2.

p-values for response surface regression models as well as linear and square effects of parameters A, B, and C along with their two-way interactions included in these models to describe changes in σ_1h and σ_24h (in mS cm⁻¹) of PALs produced by using the continuous-flow FLC-dc-APGD reaction-discharge system. Statistically significant terms included in the developed regression models are given in brackets.

	p-Values					R2, %	R2 Adjusted, %	R2 Predicted, %	S
	Model	Linear	Square	Two-Way Interactions	Lack-of-Fit
σ1h	0.000	0.000 (A, C)	-	0.016 (A × C)	0.070	99.5	99.4	98.7	0.173
σ24h	0.000	0.000 (A, B, C)	-	0.004 (A × B, A × C)	0.626	99.8	99.7	99.3	0.114
		Regression equations modelling the effect of examined parameters (A, B, and C) a
σ1h		0.258−0.128 × A + 17.269 × C−0.613 × A × C
σ24h		1.159−0.184 × A−0.019 × B + 16.519 × C + 0.007 × A × B + 0.556 × A × C

σ_1h—Electrical conductivity measured after 1 h. σ_24h—Electrical conductivity measured after 24 h. A: The flow rate of the FLC solution (NH₄NO₃) (in mL min⁻¹). B: The discharge current of the FLC-dc-APGD system (in mA). C: The NH₄NO₃ concentration in the FLC solution (in %). R²: Coefficient of determination. S: Residual standard deviation. ^a A backward-elimination-of-terms algorithm at α = 0.05 was applied to determine statistically significant terms in response to surface regression models.