University B.D.T College of Engineering

This study examines the Darcy-Brinkman model for 2-D magnetohydrodynamic fluid flow across porous stretching/shrinking surfaces. We consider water as a traditional base fluid in which the Al2O3, Silver (Ag), Titanium dioxide (TiO2), and Gold (Au) nanoparticles are submerged in preparation of a tetra-dusty nanofluid. The novelty of the present problem is to examine the influence of Boussinesq-Stokes suspension tetra dusty nanofluid flow with the Darcy-Brinkman model. The governing nonlinear partial differential equations are transferred to a set of ordinary differential equations through suitable similarity conversions. The methodology, the governing equations of fluid and dusty phases is transformed into nonlinear ODEs using similarity transformations. The findings demonstrate that the tetra nanofluid phase heat and mass transpiration performance is greater compared to the dusty phase. Developing tetra dusty nanofluid has significantly upsurged the heat transmission for manufacturing with numerous applications in engineering, biological, and physical sciences.

In the present work, we report the detailed Powder XRD Rietveld refinement and elucidation of structural factors of Ni 0.6 Zn 0.4 Gd y Fe 2-y O 4 nanoferrites. The Ni 0.6 Zn 0.4 Gd y Fe 2-y O 4 nanoferrites synthesized via low-temperature citrate gel combustion technique for the various levels of Gd3+ 3 + ion concentration (y = 0.0, 0.1, 0.15 and 0.20). The generated structural factors signify the dependence on the concentration of Gd3+ 3 + ions. The prepared samples were found to crystallize in the Fd-3m space group and also identified their occupancies; some of the Fe3+ 3 + ions of the octahedral site at the 16d position will be replaced by Gd3+ 3 + ions. The lattice constant and crystallite size dropped to a low value for y = 0.1, and then, later, noticed the small increment. The crystallite sizes of the sample are to fall in the range of 26.1 nm-37.6 nm. The cation distribution among the tetrahedral (AII) II ) and octahedral sites (BII) II ) has been estimated. The obtained values correlate with Gd3+ 3 + ion concentration, and the radius variation of A II and B II sites signifies the migration of Fe3+ 3 + ions from the B II site to the A II sites. The force constant of Metal-Oxygen bonds was determined from the infrared spectrographs; the force constant was found to be relatively low with the B II site. The DC electrical conductivity infers the semiconducting nature and distinct phase of conductivity, which is attributed to the magnetic phase change due to temperature. The magnetic curie temperatures of the sample are obtained by the Arrhenius plot, which signifies the dependence of Gd3+ion 3 + ion concentration.

This article numerically investigates the buoyancy-assisted convective flow and associated thermal characteristics in an inclined parallelogram-shaped porous geometry containing heat source and sink of different lengths placed at various locations. The left tilted wall has a hot source, and right tilted wall contains a cold sink, while the remaining regions of the inclined sidewalls are thermally insulated. The geometry is filled with fluid-saturated porous material and, in addition, an externally applied magnetic field (MF) has been supplied in lateral direction. The model equations governing the physical processes involve Darcy's law for the momentum equations and energy equations to account thermal variations. Using a stable and implicit finite difference methodology, these set of coupled and nonlinear partial differential equations are solved by reducing them to a system of linear algebraic equations. A wide range of numerical experiments are performed to determine the influence of various physical and geometrical parameters on the flow and thermal structure as well as thermal dissipation rate inside the geometry. Further, a suitable pair of inclination angles is found, at which maximum heat transport could be produced as compared to other combination of angles. Furthermore, an optimum size and location for the source-sink combination has been predicted which induces higher heat transport rates.

The mining sector, despite its significant role in the climate and biodiversity crises, has not garnered substantial attention in global discussions on these matters. COP15 presents an additional chance to integrate biodiversity and forests into standard practices within the mining sector. In 2019, a UN report highlighted a global biodiversity crisis characterized by an alarming pace of animal and plant extinctions, putting one million species at risk of vanishing. Surprisingly, the biodiversity crisis doesn't garner the same level of media and political focus as the climate crisis, despite the imperative to address both simultaneously. Preserving habitats such as forests serves a dual purpose: safeguarding species diversity while also serving as a solution to mitigate greenhouse gas emissions. Forests act as vital carbon sinks, absorbing and storing atmospheric carbon as biomass. Mining activities, essential for meeting global resource demands, have become a pervasive threat to biodiversity, leading to widespread ecological disruption and biodiversity loss.

The magnetohydrodynamic axisymmetric flow of Casson fluid over a nonlinear permeable shrinking or stretched surface is discussed in this article. Indeed, the heat transfer characteristics of an axisymmetric fluid across a non-linearly shrinking or stretching surface provided by a Casson fluid are examined analytically. Thermal radiation term is incorporated into the equation for the temperature field. Through sufficient transformations, the aforementioned non-linear PDEs are turned into ODEs. The transformed equations are then solved analytically. And an incomplete gamma function is used to depict the temperature solution analytically. The temperature equation is transformed to an incomplete gamma functions using the Rosseland approximation for the radiation and solved analytically. To estimate mass transpiration analytically, the momentum equation is investigated. To acquire the analytical results, this mass transpiration is carried out in the analysis of heat transfer under the Navier slip condition. Graphical analysis can be used to assess important physical aspects like the magnetic field, Casson parameter, mass transpiration, radiation, and Prandtl number. Dual solutions for the velocity, temperature and skin friction were obtained. In fact, for higher Prandtl number, the temperature inside the boundary layer reduces. The resulting dual solution projects that local skin friction coefficient a escalates in the first branch solution and decelerates in the second branch solution with the increase in the magnetic parameter. additionally, efficiency is increased for higher values of thermal radiation.