The rheological model of biodiesels at elevated pressures and temperatures

In the present study,an approximation is used to study viscosity as a function of pressure at different temperatures.The correlation so obtained is applied to study the viscosity of biodiesels extracted from soybean,Vistive soybean,canola,used canola,coconut and rapeseed.The computed values of viscosity from the proposed model were found to be in good agreement with experimental data throughout the range of pressure and temperature studied.The maximum average absolute relative deviation(AARD%)and mean AARD%are found to be 0.52 and 0.20,respectively,over the entire range of pressure(0.1-140 MPa)and temperature(283.15-373.15 K)for all biodiesels except rapeseed biodiesel,for which the values are 1.1 and 0.62,respectively.Furthermore,this work includes the very first investigation conducted so far on the variation of the pressure-viscosity coefficient(PVC)with pressure at different temperatures for biodiesels.The variation in PVC with the temperature is more sensitive at elevated pressures as compared to atmospheric pressure whereas the variation in PVC with pressure is more sensitive at elevated temperatures as compared to room temperature.

Photovoltaic performance of TiO_(2) and ZnO nanostructures in anthocyanin dye-sensitized solar cells

This research paper reports the fabrication and evaluation of titanium dioxide(TiO_(2))-and zinc oxide(ZnO)-based dye-sensitized solar cells with anthocyanin dye extracted from pomegranate.TiO_(2) and ZnO were synthesized using the hydrothermal synthesis and chemical bath deposition techniques,respectively.The scanning electron microscopy analysis showed that TiO_(2) had nanopillars made up of nano rods with dimensions of 111.866,90.521,and 81.908 nm,while ZnO had hexagonal patterned nanorods with lengths of 283.294 nm and diameters of 91.782 nm.The absorption spectra of the pomegranate dye were analysed and the strongest absorp-tion peak was found to be at 520 nm,which corresponds to the existing anthocyanin pigment.The band gap of pomegranate dye was noted down to be 2.45 eV.The performance of the dye-sensitized solar cells was evaluated using one sun illumination(100 mW/cm^(2))where the dye-sensitized solar cell with TiO_(2) nanopillars achieved an improved efficiency of 0.46%whereas the dye-sensitized solar cell with ZnO nanorods showed a considerably reduced efficiency of 0.42%.