National Institute of Technology, Warangal

The advanced heat transfer applications of nanofluids make it important to investigate their viscous properties.For various engineering applications, accurate measurement of dynamic viscosity of nanofluid plays a major role.This research aims to provide accurate and reliable soft computational algorithms to predict the viscosity of fly ash nanofluids and fly ash-Cu hybrid nanofluids accurately using measured data.In this work, the dynamic viscosity of water-based stable fly ash nanofluid and fly ash-Cu (80:20% by volume) hybrid nanofluid for the concentration range of 0-4 volume% determined in the temperature range of 30-60°C exptl.The nanoparticles are characterized by SEM, TEM, and DLS techniques.The stability of the nanofluids assessed by Zeta potential measurement.Outcomes show that the viscosity of hybrid nanofluid is found to be higher than fly ash nanofluid.Correlations are suggested using multiple linear regression anal. to predict the nanofluid viscosity based on the obtained results.We have adopted a novel soft computing technique, namely ANN and MGGP to optimize the dynamic viscosity data of nanofluids obtained exptl.The MGGP model predicts the viscosity values for fly ash nanofluid by (R = 0.99988, RMSE = 0.0019, and MAPE = 0.25%).In addition, statical anal. reveals that the MGGP model has excellent performance for fly ash-Cu/Water hybrid nanofluid viscosity (R = 0.9975, RMSE = 0.0063, and MAPE = 0.664%).In contrast to the ANN method and multiple linear regression anal., the MGGP approach exhibits better results in estimating nanofluid viscosity.

The transition towards sustainable energy sources necessitates advancements in energy storage technologies. This study addresses environmental concerns by transforming waste materials-specifically, using food waste (FW) as a precursor and landfill leachate (LL) as a moisture source in hydrothermal carbonization-to produce hydrochar. This hydrochar is subsequently activated and evaluated for its electrochemical performance. Thermal and chemical activation methods were employed to augment the surface properties of the hydrochar. Various characterization techniques, including CHNS, FESEM, FTIR, XRD, and BET, were utilized to comprehend the impact of the thermal and chemical activation on the morphology and physicochemical properties of the hydrochar. Electrochemical experiments were performed to evaluate the energy storage capabilities of the fabricated electrodes. The findings demonstrate that chemically activated hydrochar based electrodes exhibit superior electrochemical performance compared to thermally activated ones, showcasing nearly double specific capacitance values and enhanced cyclic stability. The symmetric cell based on chemically activated hydrochar demonstrates a specific capacitance of 362.5 F g^-1, along with impressive cyclic stability. It retains approximately 95 % of its capacitance after 2000 cycles, with over 98 % coulombic efficiency maintained throughout. Additionally, this cell achieves energy density of 32 Wh/kg at 800 W/kg power density. This remarkable performance of chemically activated electrodes highlights the potential of activated hydrochar derived from food waste as a sustainable and high efficiency material for supercapacitor applications.

Anthropogenic oil-related activities have significantly increased water pollution, posing a serious threat to the environment and human health.To address this challenge, innovative technologies for efficient oil-water separation are essential.In this study, a durable superhydrophilic and underwater superoleophobic ternary nanofibrous composite membrane was fabricated via electrospinning, utilizing polyacrylonitrile (PAN) as a polymer precursor embedded with hydrophilic candle soot nanoparticles and MXene layers.The inherent hydrophobicity of candle soot was modified to hydrophilic before incorporation into the polymer matrix.The structural morphol., wettability, thermal stability, chem. resistance, permeation flux, and separation efficiency of the ternary composite membrane were systematically investigated and compared with a binary composite membrane.The prepared ternary composite membrane achieves an underwater oil contact angle of 155 ± 1.5^°, significantly higher than the binary composite membrane′s 130 ± 1^°.It also demonstrates superior water permeation flux of 3813 ± 81 L/m² h and separation efficiency of 99 ± 0.5 % for oil-in-water emulsion.For immiscible oil/water mixtures, a water permeation flux of 4468 ± 94 L/m² h and 99 ± 0.5 % separation efficiency were achieved solely through gravity-assisted separationAddnl., the composite membrane retains over 96 % separation efficiency even after 15 cycles, demonstrating its durability through repeated use.