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In the past few years, research on the fabrication of deep eutectic solvents (DESs)-based supported liquid membranes (SLMs) is increasing tremendously due to their significant advantages such as low mass transport resistance, high performance, easy scale-up, low cost and simple operation. However, fabrication of DES-based SLMs is challenging and highly dependent on the fabrication parameters: DES properties and properties of membrane supports. Subsequently, the fabrication methods, immersion, pressure-based impregnation and vacuum filtration also affect the permeation performance of DES-based SLMs in liquids and gases separation. Furthermore, the SLM durability is influenced by the DES properties and process parameters including: temperature, pressure, and feed composition. Firstly, present work reviews the current progress and fabrication of DES-based SLMs. Subsequently, it presents a perspective on different strategies that use DESs as a unique tunable platform to design advanced SLMs for liquids and gases separation reported in the literature. In the next step, performances of the SLMs membranes for liquids and gases separation are described in details. The effects of process parameters on DES-based SLMs are also highlighted prior to the challenges. Lastly, challenges and future research opportunities are highlighted.

Background: Emerging applications in nanomaterials processing are increasingly featuring\ud multiple physical phenomena including magnetic body forces, chemical reactions and high\ud temperature behavior. Stimulated by developing a deeper insight of nanoscale fluid dynamics in\ud such manufacturing systems, in the current article, we study the magnetic nanofluid dynamics\ud along a nonlinear porous stretching sheet with Arrhenius chemical kinetics and wall transpiration.\ud Appropriate similarity transformations are employed to simplify the governing flow problem.\ud Methods: The emerging momentum, thermal energy and nanoparticle concentration ordinary\ud differential conservation equations are solved numerically with a hybrid technique combining\ud Successive Linearization and Chebyshev Spectral Collocation. A parametric study of the impacts\ud of magnetic parameter, porous media parameter, Brownian motion parameter, parameters for\ud thermophoresis, radiation, Arrhenius function, suction/injection (transpiration) and nonlinear\ud stretching in addition to Schmidt number on velocity, temperature and nanoparticle (concentration)\ud distribution is conducted. A detail numerical comparison is presented with different numerical and \ud 2\ud analytical techniques as a specific case of the current investigation.\ud Findings: Increasing chemical reaction constant parameter significantly decreases nanoparticle\ud concentration magnitudes and results in a thickening of the nanoparticle concentration boundary\ud layer. Enhancing the values of activation energy parameter significantly increases the nanoparticle\ud concentration magnitudes. Increasing thermophoresis parameter elevates both temperature and\ud nanoparticle concentration. Increasing radiation parameter increases temperature and thermal\ud boundary layer thickness. Enlarging Brownian motion parameter (smaller nanoparticles) and\ud Schmidt number both depress the nanoparticle concentration.

Arsenic-contaminated water is a major concern in many areas worldwide, causing several diseases such as cancer. There is therefore a need for advanced methods to clean waters because conventional methods have drawbacks such as generation of hazardous sludge, heavy operation and high costs. Here we review arsenic sources, chemistry, toxicity and remediation methods. We discuss also sociological aspects of arsenic prevention. Sources include surface water, groundwater and seawater. Methods include bioremediation, phyto-remediation and biofilters. Sociological aspects are public awareness, sharing information on arsenic-free water sources, removing As at the household level, building a community plant and training facilitators.

The present study analyses the dissipative influence into an unsteady electrically conducting fluid flow embedded in a pervious medium over a shrinkable sheet. The behavior of thermal radiation and chemical reactions are also contemplated. The governing partial differential equations are reformed to ordinary differential equations by operating similarity transformations. The numerical outcomes for the arising non-linear boundary value problem are determined by implementing the Successive linearization method (SLM) via Matlab software. The velocity, temperature, and concentration magnitudes for distant values of the governing parametric quantities are conferred, and their conduct is debated via graphical curves. The surface drag coefficient increases, whereas the local Nusselt number and Sherwood number decreases for enhancing unsteadiness parameter across suction parameter. Moreover, the magnetic and suction parameters accelerate velocity magnitudes while by raising porosity parameter, velocity decelerates. Larger numeric of thermal radiation parameter and Eckert number accelerates the temperature profile while by enhancing Prandtl number it decelerates. Schmidt number and chemical reaction parameters slowdowns the concentration distribution, and the chemical reaction parameter influences on the point of chemical reaction that benefits the interface mass transfer. It is expected that the current achieved results will furnish fruitful knowledge in industrious utilities.

In this article, a mathematical model is envisaged to scrutinize the aspect of swimming motile microorganisms for a steady 3D convectional flow of Carreau nanofluid towards a bidirectional stretching surface. Various researchers in the past years are collaborating in the nanotechnology field due to their improvement in heat capacity, chemotherapy for cancer, microelectronics, cooling of energy storage devices, cooling of nuclear system, air conditioning, and nanochips, etc. The novel concept of activation energy and double stratification effects is considered to analyze the flow problem. Thermal relaxation time and concentration relaxation time properties are both determined by implementing Cattaneo–Christov heat and mass flux in the energy and mass equation. Suitable similarity approximations are utilized to convert governing PDEs into dimensionless ODEs. Numerical solutions are determined to utilize collocation finite difference technique and 3-stages Lobatto-IIIa formula. The obtained ODE’s are resolved numerically by engaged built-in function bvp4c solver in computational software MATLAB. The behavior of various emerging parameters and local skin friction coefficients, local Nusselt numbers, local Sherwood number, motile microorganisms’ number, velocity profiles, temperature profile, concentration profile and microorganism concentration is elaborated with the help of graph and tables. Carreau fluid model is a particular category of established non-Newtonian fluid that exemplifies shear thinning $$ n1 $$ at high shearing rates. It is examined that the influence of the mixed convection parameter against temperature distribution both the temperature field of the shear-thinning/thickening liquids is reduced.

The thermal management of a system needs an accurate and efficient measurement of exergy. For optimal performance, entropy should be minimized. This study explores the enhancement of the thermal exchange and entropy in the stream of Eyring–Powell fluid comprising nanoparticles saturating the vertical oriented dual cylindrical domain with uniform thermal conductivity and viscous dissipation effects. A symmetrical sine wave over the walls is used to induce the flow. The mathematical treatment for the conservation laws are described by a set of PDEs, which are, later on, converted to ordinary differential equations by homotopy deformations and then evaluated on the Mathematica software tool. The expression of the pressure rise term has been handled numerically by using numerical integration by Mathematica through the algorithm of the Newton–Cotes formula. The impact of the various factors on velocity, heat, entropy profile, and the Bejan number are elaborated pictorially and tabularly. The entropy generation is enhanced with the variation of viscous dissipation but reduced in the case of the concentration parameter, but viscous dissipation reveals opposite findings for the Newtonian fluid. From the abovementioned detailed discussion, it can be concluded that Eyring–Powell shows the difference in behavior in the entropy generation and in the presence of nanoparticles due to the significant dissipation effects, and also, it travels faster than the viscous fluid. A comparison between the Eyring-Powell and Newtonian fluid are also made for each pertinent parameter through special cases. This study may be applicable for cancer therapy in biomedicine by nanofluid characteristics in various drugs considered as a non-Newtonian fluid.

Purpose The purpose of this paper is to examine the electro-magnetohydrodynamic behavior of a third-grade non-Newtonian fluid, flowing between a pair of parallel plates in the presence of electric and magnetic fields. The flow medium between the plates is porous. The effects of Joule heating and viscous energy dissipation are studied in the present study. Design/methodology/approach A semi-analytical/numerical method, the differential transform method, is used to obtain solutions for the system of the nonlinear differential governing equations. This solution technique is efficient and may be adapted to solve a variety of nonlinear problems in simple geometries, as it was confirmed by comparisons between the results using this method and those of a fully numerical scheme. Findings The results of the computations show that the Darcy–Brinkman–Forchheimer parameter and the third-grade fluid model parameter retards, whereas both parameters have an inverse effect on the temperature profile because the viscous dissipation increases. The presence of the magnetic field also enhances the temperature profile between the two plates but retards the velocity profile because it generates the opposing Lorenz force. A graphical comparison with previously published results is also presented as a special case of this study. Originality/value The obtained results are new and presented for the first time in the literature.

The current investigation scrutinized the incompressible steady flow with temperature-dependent viscosity of magnetohydrodynamics nanofluid through a vertically stretched porous sheet. The Reynolds exponential model is employed to formulate the mathematical modeling. The momentum equation is further devised utilizing the Darcy–Brinkman–Forchheimer model. Electrically conducting nanofluids encompass uniformly suspended nanoparticles in the viscous base fluid. The Buongiorno model is adopted that aspects the behavior of thermophoretic forces and Brownian motion. The momentum, mass conservative, energy, and nanoparticle concentration equations are defined with magnetic body force. The looming nonlinear coupled differential equations are resolved numerically by employing the spectral local linearization method (SLLM). The SLLM algorithm is straightforward to develop and apply, as it is based on a smooth univariant linearization of nonlinear functions. The numerical performance of SLLM is more impressive as it grows a set of equations; those are successively solved by operating the results from the one equation into the subsequent equation. To accelerate and improve the convergence for the SLLM scheme, the successive over relaxation scheme has been utilized. The accuracy of the SLLM will be confirmed through the known methods, and convergence analysis is also presented. Graphical conduct for all the emerging parameters across temperature, velocity, and concentration distributions, as well as the Nusselt number, skin friction, and Sherwood number, is presented and discussed in detail. A comparative study of the novel proposed technique along with the preceding explored literature is also granted. It is costly to affirm that the spectral local linearization scheme is uncovered to be much stable and adaptable to solve the nonlinear problems.

The thermally developed particle–fluid motion of a coupled stress fluid through a nonuniform finite wavy channel is studied. A sinusoidal peristaltic wave is traveling in the channel with a constant velocity, long wavelength and low Reynolds number. A coupled stress fluid model is applied to study the flow behavior in the channel. The mathematical model is formulated using dimensionless variables, and exact, analytical solutions are derived. The analytical expressions for the heat transfer, the velocity profile, the stream functions, the concentration profile, and the volumetric flow rate are obtained for the fluid and the particulate phase. Numerical integration is performed to determine the characteristics of the pumping rate. Results are discussed for all the variables examined in terms of the flow parameters.

The three-dimensional (3D) nanofluid flow among the rotating circular plates filled with nanoparticles and gyrotactic microorganisms is studied. A generalized form of the magnetic Reynolds number is used for the mathematical modeling of the ferro-nanofluid flow. The torque effects on the lower and upper plates are calculated. A differential transform scheme with the Pade approximation is used to solve the coupled highly nonlinear ordinary differential equations. The results show that the squeeze Reynolds number significantly suppresses the temperature, microorganism, and nanoparticle concentration distribution, and agree well with those obtained by the numerical method.

In the present research, outputs of numerical modeling of hybrid nanomaterial flow structure and thermal behavior were investigated and in-house code was implemented for simulation. Radiation terms and Lorentz force terms were included in mathematical model. Outputs demonstrate the flow structure and isotherm style with altering important parameters. Dependence of variables on Nu values was summarized in a new formula. More intensive convection should be accomplished with growth of buoyancy force and permeability. More smooth separation from the hot surface can appear with rise in permeability. Besides, it is worth mentioning that augmenting Da leads to easier nanopowder migration and thinner boundary layer generation.

The peristaltic flow of non-Newtonian nanofluid with swimming oxytactic microorganisms through a space between two infinite coaxial conduits is investigated. A variable magnetic field is applied on the flow. The bioconvection flow and heat transfer in the porous annulus are formulated, and appropriate transformations are used, leading to the non-dimensionalized ruling partial differential equation model. The model is then solved by using the homotopy perturbation scheme. The effects of the germane parameters on the velocity profile, temperature distribution, concentration distribution, motile microorganism profile, oxytactic profile, pressure rise, and outer and inner tube friction forces for the blood clot and endoscopic effects are analyzed and presented graphically. It is noticed that the pressure rise and friction forces attain smaller values for the en-doscopic model than for the blood clot model. The present analysis is believed to aid applications constituting hemodynamic structures playing indispensable roles inside the human body since some blood clotting disorders, E.g., haemophilia, occur when some blood constituents on the artery wall get confined away from the wall joining the circulation system.

This article deals with a study of Arrhenius activation energy on thermo-bioconvection nanofluid propagates through a Riga plate. The Riga plate is filled with nanofluid and microorganisms suspended in the base fluid. The fluid is electrically conducting with a varying, parallel Lorentz force, which changes exponentially along the vertical direction, due to the lower electrical conductivity of the base fluid and the arrangements of the electric and magnetic fields at the lower plate. We consider only the electromagnetic body force over a Riga plate. The governing equations are formulated including the activation energy and viscous dissipation effects. Numerical results are obtained through the use of shooting method and are depicted graphically. It is noticed from the results that the magnetic field and the bioconvection Rayleigh number weaken the velocity profile. The bioconvection Schmidt and the Peclet number decrease the microorganism profile. The concentration profile is enhanced due to the increment in activation energy and the Brownian motion tends to increase the temperature profile. The latter is suppressed by an increment of the Prandtl number.

Computational modelling for nanoparticle migration inside a permeable space has been reported. Impacts of shape factor and radiation were included in the mathematical model. CVFEM was employed to analyse magnetic force impact. Impacts of magnetic radiative parameters, buoyancy forces and nanoparticle shape on nanomaterial behaviour were demonstrated. Utilizing the Darcy model helps us to predict the behaviour of porous media. Outputs revealed higher convective mode can be achieved with augmenting buoyancy force while opposite outcome appears when magnetic field is imposed. Thermal plume vanishes with the rise of conductive mode which is gained as Hartmann increases.

In order to meet the current challenges in the fabrication of nanobiomaterials and enhancement of thermal extrusion systems, current theoretical continuation is targeted at the rheology of couple stress nanofluid by exploiting activation energy, porous media, thermal radiation, gyrotactic micro-organisms, and convective Nield boundary conditions. The heat and mass performances of nanofluid are captured with an evaluation of the famous Buongiorno model, which enables us to determine the attractive features of Brownian motion and thermophoretic diffusion. The couple stress fluid is beneficial to examine multiple kinds of physical problems because this fluid model has the capability to describe the rheology of various complex fluids, e. g., fluids having long-chain molecules as a polymeric suspension, liquid crystals, lubricants, and human and animal blood. Simultaneous behavior of the magnetic field and porosity are studied with thermal radiation effects. The distribution of velocity has been conducted by using second-order velocity slip (Wu’s slip) and activation energy features. For the dimensionless purpose, the similarity variable has been initiated, and the modeled equations are renovated sufficiently. A famous shooting method is used to determine the numerical solutions, and accurate results have been obtained. A variety of critical flow parameters is graphically illustrated with physical significance.

Our study is concerned with a generalization of the principle of Saint-Venant in the context of the theory of elastic bodies with a dipolar structure. It is an extension of the form of this principle proposed by Toupin in the case of classical linear elasticity. We consider a straight cylinder which is occupied by an dipolar elastic body that is only loaded at one end and our main finding proves that the internal energy in a portion of this cylinder, that is located at a given distance regarding the end that is loaded, is exponentially decreasing, regarding the respective distance.

This communication examines the entropy generation on the interaction of nanoparticles over a stretching porous sheet with nonlinear thermal radiation. The water-based Nanofluid having Nimonic 80a metal nanoparticles of Bricks shape. Similarity transformations are used for the simplification of governing flow equations. Numerical results for temperature, velocity, Bejan number, and entropy profiles are obtained and investigated by Successive linearization technique and Chebyshev spectral collocation scheme. Simultaneous effects of the porous medium, Radiation parameter, nanoparticle volume fraction, Prandtl number, Brinkman number, and Reynolds number are demonstrated through graphs. Additionally, the outcomes taken from the prevailing scheme ratifies magnificent conformity with the predecessors while comparing among investigations to the existing literature. The formulation for skin friction coefficient and Nusselt number are interpreted and displayed through graphs.

The attractive features of this work lies on the optimization of spinning parameters including, take-up speed and air-gap distance on the fabrication of NH2-MIL-53(Al)/CA Hollow fiber mixed matrix membranes (HFMMMs) for gases separation. The morphology and distribution of particles in the resultant HFMMMs were characterized by using FESEM and EDX mapping, respectively. FESEM images showed that the increase in take-up speed and air-gap distance reduced the outer diameters of HFMMMs from 275.5 µm to 110.1 µm and 719.1 µm to 648.4 µm, respectively. The gas permeation results exhibited that the permeance values were reduced and ideal selectivities were improved with the increment of take-up speed. Increasing trend of ideal selectivities could be because of progression of polymer orientation, packing and mono-disperse space which suppressed the non-selective voids and Knudsen pores in the HFMMMs. However, variation of air-gap distance produced “V” and “A” pattern for permeance and ideal selectivity values, respectively, for all HFMMMs spun at different take-up speeds. The HFMMM spun at optimum spinning condition at take up speed of 12.2 m/min and air gap distances of 5.0 cm showed the highest CO2/CH4 ideal selectivity of 16.0 and CO2/N2 ideal selectivity of 12.0. Hence, optimization of spinning parameters can be considered as feasible and efficient method in order to fabricate HFMMMs with higher separation performance. The enhanced CO2 permeance and ideal selectivities demonstrated that NH2-MIL-53(Al)/CA HFMMM spun at optimum condition is potential for industrial gas separation.

In this work, the effects of hybrid nanoparticles on the momentum and thermal boundary layers as well as flow characteristics and thermal performance of the hybrid nanofluid are investigated over the wedge. The fluid in the enclosure is water containing hybrid nanoparticles Cu–Ag. The physical model of homogenous hybrid nanofluid is derived using the elementary equations of thermo-hydrodynamic and co-relation's model of a mixture that supports the effective physical features. The results are calculated to measure the effects of nanoparticle concentration on thermal and momentum boundary layers and displayed in graphs for discussions. In addition, the effects of nanoparticles concentration and different compositions of hybrid nanoparticles on temperature and velocity profiles, physical properties, skin friction, and convective heat transfer coefficient are deliberated through graphs and tables. To check its heat transfer performance, a comparison of hybrid nanofluid is made between the base fluid and single material nanofluids. It is found that the efficiency of hybrid nanofluids as a heat transfer fluid is much more than conventional fluids or single nanoparticles-based nanofluids. These results in terms of boundary layers phenomena, heat transfer performance, and temperature and velocity profiles under hybrid nanomaterial could help chemical engineers to design the critical equipment in a process industry such as heat exchangers and pumps and others.

In the current work, thermal treatment, PDMS coating, and combined thermal treatment with PDMS coating methods were applied over NH2-MIL-53(Al)/cellulose acetate (CA) hollow fiber mixed matrix membranes (HFMMM) for CO2/CH4 and CO2/N2 separation. The results showed that upon thermal treatment at 170 °C, CO2/CH4 and CO2/N2 gas pair selectivities of HFMMM were improved from 9.1 to 9.9 and 7.7 to 8.4, respectively. On the other hand, CO2/CH4 and CO2/N2 gas pair selectivities of HFMMMs were improved from 9.1 to 14.1 and 7.7 to 12.0, respectively, after thermal treatment at 220 °C. Substantial increment in gas pair selectivities of the thermally treated fibers was mainly due to polymer densification, which condensed the voids between polymer and particles. Subsequently, PDMS-coated HFMMMs exhibited gas pair selectivities of 17.0 and 16.2, respectively, which were higher compared to the untreated and thermally treated HFMMM. Highest improvement of CO2/CH4 and CO2/N2 gas pair selectivities were found for combined...

In this article, the influence of heat transfer on solid particle motion in MHD Ree-Eyring fluid due to peristaltic wave has been investigated. The governing flow problem is modelled for fluid phase and particle phase with the help of continuity, momentum, and energy equations under the assumption of long wave-length and creeping flow regime. The obtained coupled ODE have been solved analytically and exact solutions have been presented. The influence of all the physical parameters are discussed for Newtonian and non-Newtonian fluid with the help of graphs. In the present analysis, it is observed that due to influence of Hartmann number, the magnitude of the velocity diminishes.

The present analysis deals with the intra-uterine nanofluid flow of a Jeffrey fluid through a finite asymmetric channel filled with gold nanoparticles. Gold nanoparticles are helpful in biomedicine to treat various diseases and locate blood flow motion through tiny vessels. The governing fluid is electrically conducting due to the presence of an extrinsic magnetic field while the magnetic Reynolds number is small, therefore, the induced magnetic effects are neglected. The thermal radiation and viscous dissipation effects are also contemplated with the energy equation. The lubrication approach has been utilized by taking a long wavelength and ignoring the inertial forces. The formulated equations are coupled and nonlinear, therefore, a perturbation approach is used to derive the series results. The results are obtained up to the second-order and plotted against various parameters for velocity mechanism, trapping profile, pressure rise, and temperature profile.

The present analysis deals with the entropy analysis of the blood flow through an anisotropically tapered arteries under the suspension of magnetic Zinc-oxide (ZnO) nanoparticles (NPs). The Jeffrey fluid model is contemplated as blood that is electrically conducting and incompressible. The lubrication approach is used for the mathematical modeling. The second law of thermodynamics is used to examine the entropy generation. The exact solutions are obtained against velocity and temperature profile with the use of computational software. The results for Entropy, Velocity, Bejan number, temperature profile, and impedance profile are discussed by plotting the graphs. ZnO-NPs have promising applications in biomedical engineering due to its low toxicity, economically reliable, and excellent biocompatibility. ZnO-NPs also emerged in medicine i.e., antibacterial and anticancer activity, and also beneficial in antidiabetic treatment. The monitoring of the blood temperature in the case of the tapered artery has supreme importance in controlling the temperature of blood in the living environment. The presence of a magnetic field is advantageous to manage and control the blood motion at different temperatures. The present outcomes are enriched to give valuable information for the research scientists in the field biomedical science, who are looking to examine the blood flow with stenosis conditions and also beneficial in treating multiple diseases.

This study deals with the mass transport phenomena on the particle-fluid motion through an annulus. The non-Newtonian fluid propagates through a ciliated annulus in the presence of two phenomenon, namely (i) endoscopy, and (ii) blood clot. The outer tube is ciliated. To examine the flow behavior we consider the bi-viscosity fluid model. The mathematical modeling has been formulated for small Reynolds number to examine the inertia free flow. The purpose of this assumption is that wavelength-to-diameter is maximal, and the pressure could be considerably uniform throughout the entire cross-section. The resulting equations are analytically solved, and exact solutions are given for particle- and fluid-phase profiles. Computational software Mathematica has been used to evaluate both the closed-form and numerical results. The graphical behavior across each parameter has been discussed in detail and presented with graphs. The trapping mechanism is also shown across each parameter. It is noticed clearly that particle volume fraction and the blood clot reveal converse behavior on fluid velocity; however, the velocity of the fluid reduced significantly when the fluid behaves as a Newtonian fluid. Schmidt and Soret numbers enhance the concentration mechanism. Furthermore, more pressure is required to pass the fluid when the blood clot appears.

The present study deals with the swimming of gyrotactic microorganisms in a nanofluid past a stretched surface. The combined effects of magnetohydrodynamics and porosity are taken into account. The mathematical modeling is based on momentum, energy, nanoparticle concentration, and microorganisms&rsquo, equation. A new computational technique, namely successive local linearization method (SLLM), is used to solve nonlinear coupled differential equations. The SLLM algorithm is smooth to establish and employ because this method is based on a simple univariate linearization of nonlinear functions. The numerical efficiency of SLLM is much powerful as it develops a series of equations which can be subsequently solved by reutilizing the data from the solution of one equation in the next one. The convergence was improved through relaxation parameters in the study. The accuracy of SLLM was assured through known methods and convergence analysis. A comparison of the proposed method with the existing literature has also been made and found an excellent agreement. It is worth mentioning that the successive local linearization method was found to be very stable and flexible for resolving the issues of nonlinear magnetic materials processing transport phenomena.

In this article, the effects of swimming gyrotactic microorganisms for magnetohydrodynamics nanofluid using Darcy law are investigated. The numerical results of nonlinear coupled mathematical model are obtained by means of Successive Local Linearization Method. This technique is based on a simple notion of the decoupling systems of equations utilizing the linearization of the unknown functions sequentially according to the order of classifying the system of governing equations. The linearized equations, that developed a sequence of linear differential equations along with variable coefficients, were solved by employing the Chebyshev spectral collocation method. The convergence speed of the SLLM technique can be willingly upgraded by successive applying over relaxation method. The comparison of current study with available published literature has been made for the validation of obtained results. It is found that the reported numerical method is in perfect accord with the said similar methods. The results are displayed through tables and graphs.

Nanofluids are potential heat transfer fluids with improved thermophysical properties and heat transfer performance. Double diffusion convection plays an important role in natural processes and technical applications. The effect of double convection by diffusion is not limited to oceanography, but is also evident in geology, astrophysics, and metallurgy. For such a vital role of such factors in applications, the authors have presented the analytical solutions of pumping flow of third-grade nanofluid and described the effects of double diffusion convection through a compliant curved channel. The model used for the third-grade nanofluid includes the presence of Brownian motion and thermophoresis. Additionally, thermal energy expressions suggest regular diffusion and cross-diffusion terms. The governing equations have been constructed for incompressible laminar flow of the non-Newtonian nanofluid along with the assumption of long wavelength. The obtained analytical expressions for velocity, temperature, and nanoparticle concentration have been sketched for various considerable parameters. The effects of regular buoyancy ratio, buoyancy parameter, modified Dufour parameter, and Dufour-solutal Lewis number have been analyzed along with wall properties and pumping characteristics. This study concludes that fluid becomes hotter with increase in regular buoyancy ratio and a modified Dufour parameter, but a decrease in temperature is observed for the buoyancy parameter. Moreover, the solutal concentration is behaving inversely against the Defour-Solutal Lewis number.

Topological indices are numerical numbers that represent the topology of a molecule and are calculated from the graphical depiction of the molecule. The importance of topological indices is due to their use as descriptors in QSPR/QSAR modeling. QSPRs (quantitative structure-property relationships) and QSARs (quantitative structure-activity relationships) are mathematical correlations between a specified molecular property or biological activity and one or more physicochemical and/or molecular structural properties. In this paper, we give explicit expressions of some degree-based topological indices of two classes of metal-organic frameworks (MOFs), namely, butylated hydroxytoluene- (BHT-) based metal-organic ( M = Co , Fe, Mn, Cr) (MBHT) frameworks and M 1 TPyP − M 2 (TPyP = 5,10,15,20 -tetrakis(4-pyridyl)porphyrin and M 1 , M 2 = Fe and Co) MOFs.

To understand the impacts of adding twisted tape inside the tube with hybrid nanomaterial, the present paper has been examined with considering FVM. New testing fluid instead of water leads to lower exergy loss. Modeling outputs were carried out for different pitch ratio and Reynolds number. Decrement trend for secondary flow was reported when pitch ratio increases, and for this reason, convective flow reduces with rise of P which results in greater exergy drop. Turbulence intensity improves with augment of Re which provides stronger interaction of nanomaterial and tube wall. So, thinner boundary layer appears with rise of Re and exergy loss deteriorates. © 2020, Akadémiai Kiadó, Budapest, Hungary.

Present study is to a great extent explains the time dependent squeezing magneto-hydrodynamic flow of Sodium Cloride-Carbon nanopowder nanofluid past a sensor surface. The current study is all about the influence of temperature dependent viscosity represented by Reynolds model and Vogel’s model on the MHD flow of the nanofluid considered. Successive Taylor series linearization method has been implemented in order to obtain the numerical solution of the transformed non-linear governing equations. It is very important to mention that irrespective of whether it is NaCl-Graphite or NaCl-Carbon Black or NaCl-Carbon nanopowder, the presence of magnetic field strength contributes the impede movement of the fluid while enhancement in the volume fraction, Reynolds model and Vogel’s model viscosity parameters exhibit the diametrically opposite trend. Keywords: NaCl-CNP nanofluid; MHD; Variable viscosity; Unsteady Squeeze flow; Sensor surface.

This article describes the interaction between solid particles and blood propagating through a capillary. A slip condition is considered on the walls of the capillary. The rheological features of the blood are discussed by considering as a two-phase Newtonian fluid model, i.e., the suspension of cells in plasma. A perturbation method is successfully applied to obtain the series solution of the governing coupled differential equations. The series solution for both fluid and particle phase are presented up to second order approximation. The expressions for the velocity and pressure distributions under slip effects are determined within a tube. Furthermore, the current results are beneficial to understand the rheological features of blood which will be helpful to interpret and analyze more complex blood flow models.

The purpose of this paper is to examine the effects of natural convection flow of viscoelastic polydimethylsiloxane non-Newtonian nanofluid under the impact of nanoparticles of different materials past a vertical cone. The implications for operating parameters have been investigated using tables and it is noticed that the nanoparticles unveil substantial impact on the thermal conductivity of base fluid. The temperature profile and the rate of heat transfer behave as an increasing function of nanoparticles. It is found that tiny size particles are more efficacious as compared to large particles on the rate of heat transfer and fluid motion. To validate the current methodology, a numerical comparison is posed with previously published data.

Purpose The purpose of this paper is to study the variable magnetic field and endoscope effects on peristaltic blood flow of nanofluid containing TiO2 nanoparticles (NPs) through a porous annulus. The Prandtl fluid model is taken into account for the present flow. The mathematical modelling comprises the temperature, continuity, NP concentration, and equations of motion which are further simplified by taking a long peristaltic wave and creeping flow regime. Design/methodology/approach After using the long wavelength approximation, the obtained highly non-linear partial differential equations are solved using the homotopy perturbation scheme. The inclusion of the pertinent parameters is discussed mathematically and graphically for the pressure rise, friction forces, temperature profile, and concentration profile. The trapping phenomenon is also investigated with the help of contours. Findings Results show that the maximum velocity distribution exists near the centre of the annulus, whereas the average time flow boosts the velocity profile. It has also been shown that flow can pass readily without enormous pressure gradient imposed on the endoscope tube unlike the case of the slim section of the problem. Practical implications The nanofluids containing titanium NPs are increasingly utilised since such type of NPs is used by several manufacturers in sunscreen blockers and different types of endoscopy. In endoscopy, the variable magnetic field is used at the tip in order to detect or treat diseases. The NPs are used since they acquire specific thermal properties as compared with base fluids. The present study provides qualitative results showing the effect of inner tube of annulus on the fluid flow, the effect of variable magnetic field, and the change in the temperature profile on the flow field. Originality/value A new model is introduced that shows the utmost pressure that works against the positive peristaltic pump. It studies the blood flow that results in extremely non-linear partial differential equations that are solved by the homotopy perturbation method. The titanium NPs are being used in blocking the rays that penetrate the epidermis causing skin burns and short ultraviolet ageing rays that cause visible wrinkles, and thus are used in the manufacturing of sunscreens that are partially absorbed through the skin.

In the current study, new types of MMMs are fabricated by incorporating NH2-MIL-53(Al) filler into cellulose acetate (CA) polymer. Subsequently, crystallinity, morphology, thermal stability, functional groups and density measurement of the resultant MMMs were verified by using different analytical tools. The results showed that the presence of NH2-MIL-53(Al) in CA matrix had enhanced the CO2 permeability, CO2/N2 and CO2/CH4 ideal selectivities from 15.5 Barrer to 52.6 Barrer, 8.8 to 23.4 and 10.7 to 28.7, respectively. The present study revealed that the addition of 15 wt% NH2-MIL-53(Al) MOF into the CA matrix resulted in highest enhancement of FFV. Furthermore, MMM loaded with 15 wt% NH2-MIL-53(Al) demonstrated highest CO2 permeability as well as CO2/CH4 and CO2/N2 selectivities of 52.6 Barrer, 28.7 and 23.4, respectively. Besides, the resultant MMM showed CO2 plasticization resistance of up to 30 bar, which is 200% increment in comparison of pristine CA membrane which is only 10 bar. This work also revealed that the resultant MMMs showed significantly higher CO2 separation performance compared to the results previously reported for CA-based MMMs. Thus, it can be concluded that the MMMs fabricated in the present work has potential for CO2 removal from the flue gas and natural gas at industrial scale.

This article is devoted to study peristaltic propulsion of particle suspended in Ree-Eyring fluid in a region where a constant magnetic field is applied. The governing flow problem is modelled for fluid phase and particle phase with the help of law of conservation of mass and momentum. It is assumed that flow is creeping and wave travelling along the wall has greater wavelength when compared with amplitude. The equations so obtained are coupled partial differential equations. The exact solutions using Eigen function expansion method is obtained and presented. The influence of all the physical parameters is discussed for Newtonian and non-Newtonian fluid with the help of graphs. In the present analysis, it is observed that due to influence of Hartmann number, the magnitude of the velocity diminishes. Keywords: Peristaltic propulsion, MHD, Particulate flows, Flow through a duct, Ree-Eyring fluid

This article addresses the electrokinetically modulated biomechanical transport through a two-dimensional asymmetric microchannel induced by peristaltic waves. Electrokinetic transport with peristaltic phenomena grabbed a significant attention due to its novel applications in engineering. Electrical fields also provide an excellent mode for regulating flows. The electrohydrodynamics problem is modified by means of Debye–Huckel linearization. Firstly, the governing flow problem is described by continuity and momentum equations in the presence of electrokinetic forces in Cartesian coordinates, then long wavelength and low/zero Reynolds (“neglecting the inertial forces”) approximations are applied to modify the governing flow problem. The resulting differential equations are solved analytically in order to obtain exact solutions for velocity profile whereas the numerical integration is carried out to analyze the pumping characteristics. The physical behaviour of sundry parameters is discussed for velocity profile, pressure rise and volume flow rate. In particular, the behaviour of electro-osmotic parameter, phase difference, and Helmholtz–Smoluchowski velocity is examined and discussed. The trapping mechanism is also visualized by drawing streamlines against the governing parameters. The present study offers various interesting results that warrant further study on electrokinetic transport with peristalsis.

This article deals with the combined effects of heat and mass transfer on the peristaltic propulsion of two-phase fluid flow through a Darcy-Brinkman-Forchheimer porous medium with compliant walls. The Sisko fluid model together with small particles is considered in the presence of extrinsic magnetic field and chemical reaction. It is well-known that different biological fluids behave like a Newtonian or non-Newtonian fluid depending upon the shear rates. The non-Newtonian fluid models are more complicated than Newtonian fluid and difficult to express using the single constitutive relationship between stress and strain rate. These constitutive equations provide a complex mathematical formulation and become numerous challenges to find numerical and analytical solutions. Small magnetic particles are helpful to manipulate and control the two-phase flow by magnetic force. Moreover, it is also beneficial in drug targeting for the treatment of different diseases. Further, two-phase flow plays an important role to examine the muscular expansion and contraction during the propagation of various biological fluids. An appropriate approximation is considered such as long wavelength and creeping flow regime to model the governing equations. Analytical solutions are obtained using the perturbation method. Moreover, numerical computations are performed to determine the features of peristaltic pumping. The results of different rheological properties for particle and fluid phase are discussed mathematically as well as graphically for different sundry parameters. The current analysis has an extensive amount of applications in medical engineering and also significant importance of smart fluid pumping systems in various engineering processes.

This paper communicates the mass transport on chemicalized fourth-grade fluid model propagating peristaltically through a curved channel in the presence of an external magnetic field. The normalized governing equations of mass, momentum, and concentration are simplified using lubrication approximations (i.e. “a long wavelength and small (or zero) Reynolds number”). The resulting equations are featuring the nonlinear third order derivative in axial velocity presenting contributions of the fourth-grade fluid model. Coordinate transformations have been employed to map the governing equations from fixed frame to wave frame. The obtained nonlinear boundary value problem is solved using a regular perturbation method and presented the expressions for velocity distribution, pressure gradient, and concentration distribution. Numerical results are explored using a computational software Mathematica. Trapping mechanism is also discussed by drawing streamlines. Streamlines have a vital importance in the analysis of fluid flow. The present model is beneficial in the study of intrauterine fluid dynamics as well as it is also applicable in vivo diagnostic, drug delivery, food diagnostic, protein chips, DNA chips, cell chips and packaging, i.e., smart sensors.

Nanofluid dynamics with magnetohydrodynamics has tremendously contributed in industrial applications recently since presence of nanoparticle in base fluids enhances the specific chemical and physical properties. Owing to the relevance of nanofluid dynamics, we analyze the nanofluid flow in the presence of gyrotactic microorganism and magnetohydrodynamics through a stretching/shrinking plate. The impacts of chemical reaction and thermal radiation on flow characteristics are also studied. To simplify the governing equations of microorganisms, velocity, concentration and temperature, the similarity transformations are employed. The couple governing equations are numerically solved using Successive Taylor Series Linearization Method (STSLM). The velocity profile, motile microorganism density profile, concentration profile, temperature profile as well as Nusselt number, skin friction coefficient, Sherwood number and density number of motile microorganisms are discussed using tables and graphs against all the sundry parameters. A numerical comparison is also given for Nusselt number, Sherwood number, skin friction, and density number of motile microorganisms with previously published results to validate the present model. The results show that Nusselt number, Sherwood number and density number diminish with increasing the magnetic field effects.

Polyvinyl alcohol (PVA) is an important industrial chemical, which is used in numerous chemical engineering applications. It is important to study and predict the flow behavior of PVA solutions and the role of nanoparticles in heat transfer applications to be used in chemical processes on industrial scale. Therefore, the present study deals with the PVA solution-based non-Newtonian Al2O3-nanofluid flow along with heat transfer over wedge. The power-law model is used for this non-Newtonian nanofluid which exhibited shear-thinning behavior. The influences of PVA and nanoparticles concentrations on the characteristics of velocity and temperature profiles are examined graphically. The impacts of these parameters on wall shear stress and convective heat transfer coefficient are also studied through tabular form. During the numerical computations, the impacts of these parameters on flow index and consistency index along with other physical properties of nanofluid are also considered. In this study, we found an improvement in heat transfer and temperature profile of fluid by distribution of Al2O3 nanoparticles. It is also noticed that resistance between adjacent layers of moving fluid is enhanced due to these nanoparticles which leads to decline in velocity profile and increases in shear stress at wall.

A comprehensive study is presented on the liquid and solid particles interaction propagating through a finite symmetric wavy channel. A non-Newtonian power law model is used to determine the flow behavior with heat and mass transfer. Furthermore, a mathematical model for electro-osmotic flow with Magnetohydrodynamics effects has been presented. The mathematical model comprises on two-dimensional conservation equations for momentum, energy, concentration, continuity with Ohm's law, chemical reaction, electrokinetic body force and viscous dissipation are formulated with the help of Cartesian coordinate system. The electric field terms are formulated into electrical potential terms using Debye length approximation, Nernst–Planck equation, and Poisson-Boltzmann equation. Moreover, an approximation of long wavelength and small Reynolds number have been used to obtain the final equations for velocity, concentration, and temperature distribution. Series solutions are presented for velocity, concentration, and temperature distribution with the help of Homotopy perturbation method up to second order. The graphical results are presented against all the involved parameters. Applications for the present study involves hemodynamics flow in biomedical engineering as well as thermal electro-osmotic micro-pumps. Furthermore, the present study is also relevant to improve thermal process in microfluidics, electrophoretic process in physiology and chromatography.

In this article, heat and mass transfer analysis on MHD blood flow of Casson fluid model due to peristaltic wave has been investigated. The governing equations of blood flow for Casson fluid model, temperature, and energy equation have been solved by taking the assumption of long wavelength and neglecting the inertial forces. The resulting coupled differential equations have been solved analytically and the exact solutions are presented. The impact of various pertinent parameters is plotted and discussed. It is found that the influence of magnetic field and fluid parameter shows similar behavior on velocity profile while its behavior is opposite for pressure rise and pressure gradient profile. Trapping phenomena have also taken into account by sketching the streamlines. The expression for pressure rise and friction forces are evaluated numerically.

In this study, we considered the unsteady peristaltic motion of a non-Newtonian nanofluid under the influence of a magnetic field and Hall currents. The simultaneous effects of ion slip and chemical reaction were also taken into consideration. The flow problem was suggested on the basis of the continuity, thermal energy, linear momentum, and nanoparticle concentration, which were further reduced with the help of Ohm's law. Mathematical modelling was executed using the lubrication approach. The resulting highly nonlinear partial differential equations were solved semi-analytically using the homotopy perturbation technique. The impacts of all the pertinent parameters were investigated mathematically and graphically. Numerical calculations have been used to calculate the expressions for the pressure increase and friction forces along the whole length of the channel. The results depict that for a relatively large value of the Brownian parameter, the chemical reaction has a dual behaviour on the concentration profile. Moreover, there is a critical point of the magnetic parameter at which the behaviours of the pressure increase and friction forces are reversed for progressive values of the power law index. The present investigation provides a theoretical model that estimates the impact of a wide range of parameters on the characteristics of blood-like fluid flows.

Air pollution is a serious threat throughout the world and may cause remarkable loss to human health and other living beings. A study was conducted to investigate the main sources of contaminants including CO, fine particle (PM2.5), coarse particle (PM10), and total suspended particulate (TSP) in the ambient air of a typical South Asian industrial city of Faisalabad, Pakistan. Twenty sites under five different city sectors (residential, health centers, commercial, industrial, and vehicular) were surveyed over one month. The average concentrations of TSP, PM10, PM2.5 and CO were 1037.62 ± 383.6 μg/m3, 434.62 ± 65 μg/m3, 35.88 ± 1.7 μg/m3, and 6.4 ± 1.95 μg/m3, respectively. The highest Air Quality Index (AQI) was recorded at the recorded commercial areas followed by the vicinities of health centers and industrial areas. The obtained results were compared against the acceptable limits of Pakistan (national) Environmental Quality Standards (NEQS) and the United States, Environmental Protection Agency (US-EPA). The results demonstrated that concentration of TSP, PM10,PM2.5, and CO in the ambient air of Faisalabad city exceeded the USEPA and NEQs air quality standards. Consequently, air pollution control should not only emphasize on regulatory particulate emissions but also involve the implementation of an integrated multi-pollutant control strategy. This research was funded through the HEC-NRPU project (No. 5635), Pakistan and IERI-GIST research project (2018), Pakistan.

In the recent year, the presence of CO2 in atmosphere has been increased tremendously after industrial revolution and it has been projected that the temperature of atmosphere will be raised about 1.4 oC to 5.8 oC by 2100. Therefore, it is important to control the emission of CO2 from industries. On the other hands, it is well documented in the literature that membrane technology is preferred over the conventional technologies (i.e. adsorption, absorption and cryogenic) due to its advantages including reliability, operational simplicity, low capital cost and easy maintenance. Among the various types of membranes, hollow fiber mixed matrix membranes (HFMMMs) exhibits great potential for CO2 separation because they offer large surface area, low pressure drop, high pressure stability, high separation performance and easy scale up compared to flat sheet mixed matrix membranes (FSMMMs) and spiral wound mixed matrix membranes (SWMMMs). Thus, there have been numerous works where researchers incorporated various inorganic fillers (i.e. zeolites, carbon, metal organic frameworks (MOFs) etc.) into different types of polymeric materials for the fabrication of HFMMMs. Despite of significant progress made in the recent year; highlights on current trends, issues and transport models of HFMMMs in CO2/N2 and CO2/CH4 separation are very limited. Therefore, in the present review article, we focused on the performance and issues of various materials based HFMMMs for CO2/CH4 and CO2/N2 separation. Major features of this review are reflected in the following three aspects: (i) comprehensive study on the performance of HFMMMs for CO2/N2 and CO2/CH4 separation (ii) issues with the fabrication of HFMMMs in CO2/N2 and CO2/CH4 separation (iii) prediction of transport models for HFMMMs in gases separation. In the present review article, it has been observed that the MOF based HFMMMs showed higher CO2/N2 and CO2/CH4 separation performance compared to the zeolite, carbon and other fillers based HFMMMs. On the other hand, ZIF-8, ZIF-93 and amine functionalized MIL-based HFMMMs showed higher CO2/N2 and CO2/CH4 separation performance compared to other fillers based HFMMMs. Among MOF based HFMMMs, amine functionalized MIL based HFMMM showed great potential for CO2 separation from N2 and CH4. Furthermore, the present paper reviewed the different issues with fabrication of HFMMMs including dope fluid composition; bore fluid composition and spinning parameters. It has been found that the spinning parameters including, dope fluid flow rate, bore fluid flow rate, dry gap height, force convection gas flow rate, take up speed, jet–stretch ratio and draw ratio effects the morphology of membrane and thus, performance of HFMMMs in CO2 separation. Therefore, the achievement of optimum and proper value of spinning parameters during the fabrication of HFMMMs is also need to be explored to enhance the performance of the membranes. Besides, from the review work on the transport models used for HFMMMs in gases permeations, it has been concluded that modified Maxwell model and modified Pal model will be more appropriate model to study the transport behavior of gases through HFMMMs contains low and higher loading of fillers, respectively.

In this article, effects of heat and mass transfer on MHD peristaltic motion of solid particles in a dusty fluid are investigated. The effects of nonlinear thermal radiation and Hall current are also taken into account. The relevant flow analysis is modelled for fluid phase and dust phase in wave frame by means of Casson fluid model. Computation of solutions is presented for velocity profile, temperature profile and concentration profile. The effects of all the physical parameters such as particle volume fraction, Hartmann number, Hall Effect, Prandtl number, Eckert number, Schmidt number and Soret number are discussed mathematically and graphically. It is noted that the influence of magnetic field and particle volume fraction opposes the flow. Also, the impact of particle volume fraction is quite opposite on temperature and concentration profile. This model is applicable in smart drug delivery systems and bacteria movement in urine flow through the ureter.

In this article, we have considered the simultaneous influence of ohmic heating and chemical reaction on heat and mass transfer over a stretching sheet. The effects of applied magnetic field are also taken into consideration while the induced magnetic field is not considered due to very small magnetics Reynolds number. The governing flow problem comprises of momentum, continuity, thermal energy and concentration equation which are transformed into highly nonlinear coupled ordinary differential equations by means of similarity transforms, which are then, solved numerically with the help of Successive Linearization method (SLM) and Chebyshev Spectral collocation method. Numerical values of skin friction coefficient, local Nusselt number, and Sherwood number are also taken into account with the help of tables. The physical influence of the involved parameters of flow velocity, temperature and concentration distribution is discussed and demonstrated graphically. The numerical comparison is also presented with the existing published results and found that the present results are in excellent agreement which also confirms the validity of the present methodology.

In this paper, the peristaltic transport of a MHD dusty three-dimensional biorheological (Casson) fluid in a duct is investigated. The governing flow problem is based on the continuity and momentum equations. These equations are modeled for both the fluid phase and particle phase by means of a creeping flow regime and long wavelength assumption. The exact solution has been obtained for the resulting partial differential equation by means of the eigenfunction expansion method. Graphical results are discussed against all the emerging parameters such as the Hartmann number, particle volume fraction, Casson fluid parameter etc. Numerical integration has been used to determine the pumping characteristics. Trapping phenomena are also discussed and sketched by drawing streamlines for all the physical parameters. A graphical comparison is also presented with the previously published data and it is found that the present results are in excellent agreement, which assures that the current methodology and results are correct. It is observed that the velocity profile diminishes due to a greater influence of the particle volume fraction and Hartmann number. Moreover, it is found that the Casson fluid parameter enhances the fluid velocity near the walls of the duct and opposes the flow in the middle of the duct.