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A number of mathematical methods have been developed to determine the complex rheological behavior of fluid’s models. Such mathematical models are investigated using statistical, empirical, analytical, and iterative (numerical) methods. Due to this fact, this manuscript proposes an analytical analysis and comparison between Sumudu and Laplace transforms for the prediction of unsteady convective flow of magnetized second grade fluid. The mathematical model, say, unsteady convective flow of magnetized second grade fluid, is based on nonfractional approach consisting of ramped conditions. In order to investigate the heat transfer and velocity field profile, we invoked Sumudu and Laplace transforms for finding the hidden aspects of unsteady convective flow of magnetized second grade fluid. For the sake of the comparative analysis, the graphical illustration is depicted that reflects effective results for the first time in the open literature. In short, the obtained profiles of temperature and velocity fields with Laplace and Sumudu transforms are in good agreement on the basis of numerical simulations.

It observers that an object is submerged in a liquid, more pressure is applied to its bottom surface than its top surface, as a result pressure rises within depth of fluids. A buoyancy force is generated due to the pressure difference. In the current investigation, the mathematical formulation of bio-convective stagnation point flow of a radiative Maxwell fluid with multiple slip effect on an exponentially porous stretching surface is analyzed thoroughly. The buoyancy assisting and opposing conditions with magnetic field are discussed in the current investigation. Moreover, the energy and concertation equations are formulated by the utilization of Cattaneo–Christov theory and non-uniform heat source/sink. The flow model is developed in the form of partial derivatives, then use the similarity variables to convert the physical system into nonlinear ordinary derivative. The nonlinear system is tackled numerically with the help of Bvp4c approach on the MATLAB. The graphical upshots for various emerging parameter are observed with two aspects: buoyancy assisting λ > 0 and buoyancy opposing λ < 0 . The observation shows that the greater values of mixed convection parameter improves the fluid velocity for assisting flow λ > 0 , while declining trend is noticing for opposing flow situation λ > 0 . Further, it is worth noticing that stronger inputs of thermal and concentration relaxation parameter yield lesser thermal and concentration diffusivity, which reduces the temperature and nanoparticles concentration.

Efficient heat transfer in inclined enclosures is critical for applications in thermal management, energy storage, and electronic cooling, yet the combined effects of micropolar nanofluids, porous media, and electromagnetic forces remain underexplored. This study investigates conjugate convective heat transfer in a porous inclined cavity filled with micropolar nanofluid under a tilted Lorentz force, where local thermal non-equilibrium is assumed between fluid and solid phases. The governing nonlinear equations are solved using the finite difference method (FDM), with adiabatic vertical walls and thermally conductive horizontal walls. To reduce computational cost, an artificial neural network (ANN) is trained on FDM-generated data to predict local Nusselt numbers. The results show that increasing the thickness of the solid wall from 0.05 to 0.3 reduces the maximum temperature by up to 84.28%, indicating improved thermal insulation characteristics. Additionally, higher solid volume fractions (up to 0.2) and stronger micropolar effects (vortex viscosity ratio up to 2.0) increase thermal resistance, resulting in a reduction in heat transfer of approximately 20%. Furthermore, enhancing the porosity of the medium from 0.1 to 0.9 leads to a 76.67% improvement in convective flow. This work advances the state of the art by coupling micropolar nanofluid dynamics, porous media, and tilted magnetic fields in inclined enclosures—an area not previously addressed with such detail. The integration of ANN with physics-based modeling offers a novel, high-fidelity, and computationally efficient framework for the optimization of complex thermal systems.

The present investigation aims to examine the heat flux mechanism in the hagnetohydrodynamic (MHD) mixed convective flow of Williamson-type fluid across an exponential stretching porous curved surface. The significant role of thermal conductivity (variable), non-linear thermal radiation, unequal source-sink, and Joules heating is considered. The governing problems are obtained using the Navier–Stokes theory, and the appropriate similarity transformation is applied to write the partial differential equations in the form of single-variable differential equations. The solutions are obtained by using a MATLAB-based built-in bvp4c package. The vital aspect of this analysis is to observe the effects of the curvature parameter, magnetic number, suction/injection parameter, permeability parameter, Prandtl factor, Eckert factor, non-linear radiation parameter, buoyancy parameter, temperature ratio parameter, Williamson fluid parameter, and thermal conductivity (variable) parameter on the velocity field, thermal distribution, and pressure profile which are discussed in detail using a graphical approach. The correlation with the literature reveals a satisfactory improvement in the existing results on permeability factors in Williamson fluids.

Adding solid particles of nanometer scale to fluids is one of the most important passive methods of enhancing heat transfer performance. However, this gives numerous chances to investigate new frontiers, but also raises remarkable difficulties. Nanofluids act as suspension that can be obtained by dispersing nanometer-sized nanoparticles (1-100nm) in host fluids with the aim of enhancing thermal properties. This paper is a review of recent studies on boiling heat transfer of nanofluids for pool and convective flow boiling of nanofluids. The research results, collected since 2012 to present of the recent survey are reviewed and briefly outlined. An emphasis is put on the enhancement and the deterioration of the boiling heat transfer coefficient and critical heat flux of pool and convective flow boiling of nanofluids. Other important parameters affecting the boiling of nanofluids are identified and discussed in this review. While preparing future studies is greatly encouraged in order make this phenomenon well understood. nema

Several chromatographic approaches have been established over the last decades for the production of pharmaceutically relevant viruses. Due to the large size of these products compared to other biopharmaceuticals, e.g., proteins, convective flow media have proven to be superior to bead-based resins in terms of process productivity and column capacity. One representative of such convective flow materials is membranes, which can be modified to suit the particular operating principle and are also suitable for economical single-use applications. Among the different membrane variants, affinity surfaces allow for the most selective separation of the target molecule from other components in the feed solution, especially from host cell-derived DNA and proteins. A successful membrane affinity chromatography, however, requires the identification and implementation of ligands, which can be applied economically while at the same time being stable during the process and non-toxic in the case of any leaching. This review summarizes the current evaluation of membrane-based affinity purifications for viruses and virus-like particles, including traditional resin and monolith approaches and the advantages of membrane applications. An overview of potential affinity ligands is given, as well as considerations of suitable affinity platform technologies, e.g., for different virus serotypes, including a description of processes using pseudo-affinity matrices, such as sulfated cellulose membrane adsorbers.

Purpose The purpose of this paper is to numerically study the unsteady double-diffusive mixed convective stagnation-point flow of a water-based nanofluid accompanied with one salt past a vertical flat plate. The effects of Brownian motion and thermophoresis parameters are also introduced through Buongiorno’s two-component nonhomogeneous equilibrium model in the governing equations. Design/methodology/approach In the present explanation of double-diffusive mixed convective model, there are four boundary layers entitled: velocity, thermal, solutal concentration and nanoparticle concentration. The resulting basic equations are solved numerically via an efficient Runge–Kutta fourth-order method with shooting technique after the governing nonlinear partial differential equations are converted into a system of nonlinear ordinary differential equations by the use of similarity transformations. Findings To avail the physical insight of problem, the effects of the mixed convection parameter, unsteadiness parameter and salt/nanoparticle parameters on the boundary layers behavior are investigated. Moreover, four possible types of diffusion problems entitled: double-diffusive nanofluid (DDNF), double-diffusive regular fluid (DDRF), mono-diffusive nanofluid (MDNF) and mono-diffusive regular fluid (MDRF) are considered to analyze and compare them in concepts of heat and mass transfer. Originality/value The results demonstrate that, for a regular fluid, without nanoparticle and salt (MDRF), the dimensionless heat transfer rate is smaller than other diffusion cases. As we include nanoparticle and salt (DDNF), the rate of heat transfer increases due to an increase in thermal conductivity and rate of diffusion of salt. Moreover, it is observed that the highest heat transfer rate is obtained for the situation that the thermophoretic effect of nanoparticles is negligible. Besides, the heat transfer rate enhances with the increase in the regular double-diffusive buoyancy parameter of salt.

Purpose The formulation of nonlinear convective non-Newtonian material is reported in this communication. Aspects of thermal radiation and heat source are taken into account for heat transport analysis. The novel stratifications (thermal and solutal) and convective conditions are considered simultaneously. The boundary-layer concept is implemented to simplify the complex mathematical expressions. Design/methodology/approach The well-known optimal homotopy scheme develops the computations. Optimal values regarding nonzero auxiliary variables are calculated and examined. Findings Nonlinear convective flow; Thixotropic non-Newtonian material; Thermal radiation; Heat source; Stratifications and convective conditions; Buongiorno model. Originality/value To the best of authors’ knowledge, no such analysis has yet been reported.

The growth of the leading countries’economies leads to the rapid development of megacities and changes in urban areas. Currently, more and more modern high-rise civil buildings are being built, resulting in an increasing density of urban areas and the activity of transport infrastructure. This causes major changes in the structure of urban development, which leads to a change in aeration and microclimatic conditions in urban areas. Solar radiation plays an active role in shaping the microclimate of the urban space, which aggravates the heat and wind regime of the urban environment. This is especially acute in the southern cities with hot climatic conditions. The article analyzes modern urban areas and factors affecting their microclimate. The role of temperature inversions in the formation of microclimatic conditions is indicated. Using the example of the yard space in Dushanbe, measurements and field studies were carried out; graphs of the climatic indicators of the urban area were plotted. The role of solar radiation in the formation of convective flows and microclimatic conditions of urban space is discussed.

A stable growth mode of a single dendritic crystal solidifying in an undercooled ternary (multicomponent) melt is studied with allowance for a forced convective flow. The steady-state temperature, solute concentrations and fluid velocity components are found for two- and three-dimensional problems. The stability criterion and the total undercooling balance are derived accounting for surface tension anisotropy at the solid-melt interface. The theory under consideration is compared with experimental data and phase-field modeling for Ni98Zr1Al1 alloy.