M. O. NWANKWO ET AL.
372
Table 9. Model summary and parameter estimates of the unified equation.
Dependent Variable: Y
Model Summary Parameter Estimates
Equation R Square F df1 df2 Sig. Constant b1 b2
Quadratic 0.935 171.551 2 24 0.000 1.032 −0.002 1.889E-6
The independent variable is T.
Regression Equation: 62
1.0320.0021.899 10
tt
.
5. Conclusion
The conclusion that can be drawn from the foregoing
discussions is that ocimum basilicum is a good corrosion
inhibitor since its pH value of 6.7 falls within the region
in which passivation occurs in the Poubaix diagram [20].
Again the quadratic model which fits each with a nearly
perfect correlation suggest in strong terms that room tem-
perature corrosion progression can no longer be said to
be only logarithmic but also has a significant quadratic part
that must be accounted for during corrosion characteriza-
tions. Additionally, the unification of the model equa-
tions into a single generalized form also shows that it is
henceforth possible and accurately so, to use the equation
to make futuristic computations of corrosion penetration
rates for engineering mild steel in acidic environments
with ocimum basilicum serving as a veritable inhibitor.
6. Acknowledgements
The authors wish to acknowledge the Department of In-
dustrial Chemistry of Ebonyi State University for grant-
ing them the permission to use their facilities for the
work. Dr. S. O. Maliki of the Department of Industrial
Mathematics, Ebonyi State University is also acknowl-
edged for his immense contributions.
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