Application of Response Surface Methodology for Optimization of Urea Grafted Multiwalled Carbon Nanotubes in Enhancing Nitrogen Use Efficiency and Nitrogen Uptake by Paddy Plants

Table 5

Analysis of variance for NUE using CCD.

Source	Sum of squares	Degree of freedom	Mean square	-value	value
Model	462.90	5	92.58	10.32	0.0040
	119.67	1	119.67	13.34	0.0082
	236.74	1	236.74	26.39	0.0013
	31.25	1	31.25	3.48	0.1042
	52.66	1	52.66	5.87	0.0459
	73.80	1	73.80	8.23	0.0241
Residual	62.80	7	8.97
Lack-of-Fit	62.80	3	20.93
Pure error	0.000	4	0.000
Cor total	525.70	12

-Squared = 0.8805; Adj -Squared = 0.7952; Pred -Squared = −1.1297; Adeq Precision = 11.202.
is amount of f-MWCNTs.
is functionalization reflux time.