Davangere University

About: Davangere University is a education organization based out in Davangere, India. It is known for research contribution in the topics: Nanofluid & Heat transfer. The organization has 236 authors who have published 413 publications receiving 3673 citations.

Numerical simulation of carbon nanotubes nanofluid flow over vertically moving disk with rotation

Abstract: In this article, we explored the impact of magnetic field on nanofluid flow in the presence of SWCNT and MWCNT with water as a base fluid and flow is caused due to a vertically upward/downward moving rotating disk. The problem is constructed in such a way that the equilibrium of controlling the physical object is finally reduced for those conveyed in the traditional von Karman’s investigation of viscous pumping in a rotating disk. The framed partial differential equations (PDEs) are reduced into ordinary differential equations (ODES) by considering suitable similarity variables. The numerical solutions are obtained by using Runge–Kutta–Fehlberg’s fourth fifth order method (RKF-45) by adopting shooting technique. The computation of rate of heat transfer is analyzed​ through graphs. Further variation in velocity and thermal profiles for various dimensionless parameters are studied briefly and illustrated with the help of graphs. The outcomes reveal that, upsurge in expanding/contraction parameter increases the fluid velocity and it is more in MWCNT–water than SWCNT–water nanofluid flow. The escalation in values of magnetic parameter increases the thermal profile of both single and multi-wall CNTs with water based nanofluid but declines radial, azimuthal velocity profiles.

Green Synthesis of Zinc Oxide Nanoparticles (ZnO NPs) for Effective Degradation of Dye, Polyethylene and Antibacterial Performance in Waste Water Treatment

Abstract: At present, there is a vital need for river water purification by developing new approaches to eliminate bacterial biofilms, textile dyes, and Low-Density Polyethylene (LDPE) plastics that pose severe threats to human and environmental health. The current work put forward the construction of an eco-friendly green strategy to synthesize zinc oxide nanoparticles (ZnO NPs) using areca nut (Areca catechu) extract and their application to tackle the challenges in water purification. Prepared biogenic NPs were characterized by X-ray diffraction analysis (XRD), Fourier Transform Infra-Red (FT-IR), Energy Diffraction Spectroscopy (EDS), Scanning Electronic Microscopy (SEM), Transmission Electron Microscopy (TEM) analysis, confirmed the spherical shape in 20 nm and UV–vis spectroscopy. The characteristic absorption band exhibited at 326 nm confirmed the formation of ZnO NPs using UV–vis spectroscopy. Among all the tested bacterial pathogens, the E. coli at 50 µg/mL concentration showed the highest inhibition of biofilm activity, followed by the highest growth curve, cellular leakage, and potassium ion efflux. The ZnO NPs observed with photo-degradation of Rhodamine-B (Rh-B), Methylene Blue (MB), and Nigrosine dyes under sunlight irradiation at different time intervals. Finally, the photocatalytic activity of LDPE-ZnO NPs nanocomposite film showed the highest degradation under solar light irradiation were confirmed through photo-induced weight loss, SEM, FTIR, and MALDI-TOF analysis. This study demonstrates ZnO NPs exhibit efficacy against biofilm formation, degradation of photocatalytic textile dyes, and low-density LDPE film under solar light irradiation, which can be a step forward in water purification.