are present in larger amounts in the hydro-distilled essential oil than the SFME essential oil, but the extract obtained by SFME is more concentrated in oxygenated compounds.
SFME is proposed an "environmentally friendly" extraction method suitable for sample preparation prior to essential oil analysis.
The solubilisation is then the limiting step and solubility becomes the essential parameter which induces the microwave SFME selective extraction.
Then the test is conducted with 20% SFME and 40% SFME on coated engine with normal injection pressure and normal injection timing.
Due to the coating of piston in the present investigation it is found that the thermal efficiency of the coated 40% SFME at retarded condition is 9% higher than standard diesel engine.
At maximum loading the coated piston with 20% SFME shows 8% reduction in SFC at retardation compared to standard engine at normal injection.
At low load conditions coated engine 20% SFME with normal injection releasing more unburned hydrocarbons and at peak load conditions the same blend released relatively low HC due to attaining of complete combustion with high temperature availability in the ceramic coated piston.
The CO release for retarded injection of 20% SFME is the lowest among all different experimental set as shown in fig.
The coated piston with 20% and 40% SFME released lowest level compared to all other set of run and it is 7% lower than the standard diesel engine.
The NOx release of present experimental investigation showed some interesting output when compared to 100% SFME fuel operation  and it is plotted in fig.
The smoke release is increased 19% more than standard engine for coated 20% and 40% SFME at normal injection, which clearly indicates that the smoke can be reduced for blends in the coated engine with fuel advancing in thermal barrier coated engine.