K. S. Rangasamy College of Technology

The escalating interest in utilizing non-competitive feedstocks for biodiesel production suggests waste cooking oil as a cost-effective resource being explored.The present work highlights the bioconversion of waste cooking oil catalyzed by heterogeneous ZnO nano-catalyst derived from Aloe vera.The performance of DI-CI engine was analyzed for the biodiesel blends of B20 & B20GS50 with externally cooled electronically controlled EGR.The green synthesized zinc oxide nano particle acts as a dual performer including transesterification catalyst and fuel additive.The results revealed that nano catalyzed biodiesel potential of waste cooking oil was 92 ± 0.24 %.The kinetic modeling demonstrated first order reaction kinetics with k = 0.015 min^-1 and thermodn. anal. evidenced endothermic nature of transesterification with ΔH = 39.74 kJ/mol.UV-Vis spectra confirm the presence of zinc oxide nanoparticles at 564 cm^-1.FTIR anal. exhibited peaks at 2928, 1442, 3428 and 1750 cm^-1 indicate alkane (CH₂), C=O, hydroxyl and amino functional moieties resp.The sharp peak indicates good crystallinity of the nanoparticles in XRD anal.Machine learning tools such as RSM and ANN demonstrated lesser RMSE and R² values of 0.1555, 0.2276, 20.33 and 83.54 for BTE and NO_x resp.The higher R² value of RSM such as 0.9891 and 0.9999 corresponding to BTE and NO_x indicates the reliability of the model towards performance optimization.RSM predicted optimized parameters are 100 % load, 81.564 % biodiesel and 20 % EGR resulted with 31.259 % BTE and 169.2 ppm NO_x.The predictive ability of RSM was higher than ANN.Therefore, the study recommended RSM for performance optimization of DI-CI engine.

Alumina-zirconia (AZ) nanoparticles were synthesized via a pilot-scale hot-air spray pyrolysis method.The structural, morphol., and chem. characteristics of the synthesized AZ nanoparticles were systematically characterized.The nanoparticles reveal a high-crystalline t-ZrO₂-stabilized amorphous alumina matrix with a crystalline size of 9.7 nm and a particle size of 20 nm, exhibiting a highly spherical shape morphol. and a surface area of 36.28 m²/g.Hybrid nanocomposite coatings were fabricated on mild steel (MS) specimens by incorporating varying concentrations of AZ nanofillers (0.05, 0.10, and 0.15 wt%) of filler into epoxy resin (EH) with subsequent functionalization of oleic acid.Results showed that higher concentrations of alumina-stabilized t-ZrO₂ nanoparticles led to a significant reduction in surface porosity of nanocomposite coating, from 1.106 to 0.319 μm.Meanwhile, it exhibited a hardness of 292 MPa, Young′s modulus of 2.34 MPa, and surface roughness of 1.237 nm with a maximum contact angle of 82.92 ± 5.6⁰, demonstrating enhanced mech. strength and a more hydrophobic nature.Electrochem. analyses, such as the Nyquist Plot and Tafel polarization plot, revealed that nanocomposite coatings significantly improved corrosion resistance in a saline medium of 3.5 wt% NaCl and natural seawater environments, achieving efficiencies of 95.88 % and 82.36 %, resp.These findings highlight the potential of AZ-reinforced epoxy nanocomposite coatings as advanced anticorrosion applications in real-time seawater conditions.

Araucaria columnaris leaf extract-mediated molybdenum trioxide (MoO₃) nanorods were synthesized using ammonium molybdate as a precursor.Biomimetic scaffolds were prepared by solvent casting using chitosan-sodium alginate and MoO₃ nanorods.Physico-chem. characteristics of MoO₃ nanorods and biomimetic scaffolds were scrutinized using appropriate characterization techniques.The XRD and FE-SEM anal. claimed that molybdenum has an orthorhombic structure with the morphol. of α-phase and the nanorods, resp.TGA anal. on MoO₃ nanorods retained 86.4 weight% of mass when its temperature extended to 935 °C.The antioxidant and antibacterial properties of MoO₃ nanorods and their biomimetic scaffolds have been examinedIn vitro, the bioactivity of MoO₃ nanorods and their biomimetic scaffolds was assessed using SBF for biomineralization and PBS for swelling and protein absorption.The MoO₃ nanorods and scaffolds show better in vitro cytotoxicity against adenocarcinoma- MCF-7 cell lines at 82 % and 75 %, resp.Bio-electrochem. behaviors of a model Ti alloy with nanocomposite scaffold against PBS solution were investigated, and its biomimetic scaffold with concertation of α-MoO₃ 500 mg offered a better tissue regeneration response.