http://nopr.niscpr.res.in/handle/123456789/63561 2026-10-10T23:52:44Z 2026-10-10T23:52:44Z Digambar Kaldante, Yogeshwar Natha Shirsat, Ramesh Ganpat Chaskar, Manohar http://nopr.niscpr.res.in/handle/123456789/63576 2024-03-12T09:35:25Z 2024-03-01T00:00:00Z

Title: A comparative photocatalytic degradation study of Thymol blue dye over pristine ZnO and Er-doped ZnO Authors: Digambar Kaldante, Yogeshwar; Natha Shirsat, Ramesh; Ganpat Chaskar, Manohar Abstract: Existing work describes the synthesis of pristine ZnO and Er-doped ZnO by mechanochemical method and evaluation of the photocatalytic activity synthesized samples towards photochemical degradation of Thymol Blue dye. The right calcination temperature has been gained from TGA-DTA analysis. FTIR results show the formation metal oxides from their respective precursors upon calcinations. XRD data obtained for ZnO and Er-ZnO clearly suggest the hexagonal wurtzite crystallite structures. FE-SEM images established nanocrystalline morphology. The elemental pureness of these samples is confirmed by EDX study. The optical band gaps are determined from UV-Visible spectroscopic studies. PL spectra are used to explore the additional information about optical properties of said photocatalysts. The comparative studies of photocatalytic activities of these materials towards degradation of Thymol Blue dye is carried out with respect to involved operational parameters. The possible degradation intermediates and products are also illustrated with HPLC & HRMS techniques. Page(s): 175-185

2024-03-01T00:00:00Z Subramanyam Reddy, A. Kumar Challa, Kalyan Srinivas, S. Ramamohan, T.R. Vajravelu, K. http://nopr.niscpr.res.in/handle/123456789/63575 2024-03-12T09:33:44Z 2024-03-01T00:00:00Z

Title: Influence of Ohmic heating and thermal radiation on chemically reactive pulsatile flow of Casson nanofluid in a vertical porous channel embedded in non-Darcy porous medium Authors: Subramanyam Reddy, A.; Kumar Challa, Kalyan; Srinivas, S.; Ramamohan, T.R.; Vajravelu, K. Abstract: The present study examines the effects of the pulsatory flow of Casson nanofluid using Buongiorno's model in a vertical channel. On the left wall, fluid is injected with some velocity and removed at the opposite wall at the same rate. The solutions for velocity, temperature, nanoparticle concentration, heat, and mass transfer rates are calculated using the Runge- Kutta 4th order approach along with the Shooting method. The impact of different parameters, including thermophoresis, chemical reaction, Lewis number, and heat source or sink parameter, are illustrated graphically. The results show that the Brownian motion parameter increases the temperature profile, while the chemical reaction parameter decreases the concentration profile. Further, a tabular representation of the steady and unsteady heat and mass transfer rates at the left wall is provided. The higher values of the chemical reaction parameter result in an increase in both the steady and unsteady Sherwood number distributions. Page(s): 186-196

2024-03-01T00:00:00Z Jyothi, N Vijayakumar, A G http://nopr.niscpr.res.in/handle/123456789/63574 2024-03-12T09:31:38Z 2024-03-01T00:00:00Z

Title: Exact solutions on magnetohydrodynamic Casson nanofluid EG-GO and EG-MWCNT over a vertical plate with shape factors: Caputo fractional derivative Authors: Jyothi, N; Vijayakumar, A G Abstract: The aim of the present work is to apply the Caputo-fractional derivative to the heat transformation of unsteady incompressible magnetohydrodynamic (MHD) Casson nanofluid flow. Ethylene Glycol-Graphene oxide and Ethylene glycol-Multiwall Carbon nanotubes considered as nanofluids. The current study helps in understanding the fluid dynamics involved in water purification, energy conservation, solar energy, coolants, cancer therapies, and physiological fluid dynamics. By using appropriate non-dimensional variables, the leading PDE of the problem are non dimensionalized. The governing equations are solved by the combined integral transforms of Fourier sine and Laplace transform technique. For an extensive study of the problem, graphical illustrations and tables are developed by using the MATLAB software. The effects of the order of the Caputo derivative, thermal Grashof number, viscous dissipation, and Casson parameter oscillations on the fractional heat and momentum equations are inspected. The thermal and velocity profiles are increased for thermal Grashof number and Casson parameter. Symmetry phenomena are also observed in the case of cooling and heating plate for thermal Grashof number. Different shapes of nanoparticles are performed for ordinary fractional parameters which is increased for temperature as well as velocity. Page(s): 197-212

2024-03-01T00:00:00Z Ghader, Sattar Rezaei, Hamed Ghareghashi, Abbas http://nopr.niscpr.res.in/handle/123456789/63573 2024-03-12T09:28:29Z 2024-03-01T00:00:00Z

Title: Recovery of lead from copper anode slime and study of kinetics of lead dissolution Authors: Ghader, Sattar; Rezaei, Hamed; Ghareghashi, Abbas Abstract: In this study, an effective method of recovering metallic lead from copper anode slime is investigated. A method of leaching with nitric acid at atmospheric pressure is also proposed, and the effect of various factors on the leaching effect is studied. The kinetics of leaching is studied, and a model of the leaching process is established. Copper anode slime residues, rich in valuable metals, provide one of the critical resources for recycling metals in favourable conditions. A green acid leaching process for lead (Pb) enrichment from copper (Cu) anode slime is developed in this study. Under ideal conditions, HNO3 successfully leached 72% Pb in 2 h. The optimum leaching conditions are the stirring speed of 1000 rpm, the temperature of 90 °C, the HNO3 concentration of 4 M, and the solution-to-anode slime ratio of 10:1. The kinetics of lead leaching from anode slime is developed according to the phase composition and shape of the leaching residue and raw material. The modified grain model is considered for this purpose. MATLAB is used to solve the model in isothermal mode by using the orthogonal collocation method. The results are good compatibility with experimental data. The activation energy is calculated using the parameters derived from the modified tablet-grain model based on the test conditions. Therefore, the lead recovery under the proposed process has a promising potential for treating Cu anode slime. Page(s): 213-221

2024-03-01T00:00:00Z