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 1

Experimental codes and levels of independent variables for RSM optimization.

Variables	Units	Levels
		−1.682	−1	0	+1	+1.682
MWCNTs,	wt%	0.1	0.2	0.3	0.5	0.6
Functionalization reflux time,	Hour	12	15	18	21	24