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IntroductionStenosis is one of the most frequent anomalies in blood circulation. It is known as a partial occlusion of the blood vessels due to the accumulation of cholesterols, fats and smooth muscle cells. The occlusion makes the walls thickened and hardened which may reduce the volume of the blood that travels through the arteries. This leads to a reduction in the amount of oxygen and nutrients transported to the peripheral organs. The study by Moayeri and Zendehboodi [1] noted that once the occlusion is formed, the blood flow is significantly altered and fluid dynamical factors play important roles as the stenosis continues to enlarge leading to the development of cardiovascular diseases, such as heart attack and stroke. Thus, the study of blood flow through a stenosed artery is very important due to the fact that the development of diseases is related to the nature of blood movement and the mechanical behaviour of the blood vessel walls.Cavalcanti [2] considered a mild stenosis with 2% area reduction. The study used a thin-rigid wall model, along with the continuity and axial component of the Navier-Stokes equations to obtain an approximate analytical solution to the physiological flow of blood. A nonlinear two-dimensional flow of blood in a mild stenosed flexible artery was investigated by Chakravarty et al. [3] by treating the arterial wall as an anisotropic, linear viscoelastic and an incompressible circular cylindrical membrane shell. Chakravarty and Mandal [4] extended the work by considering the bifurcated arteries with a mild stenosis. The vascular wall deformability is taken to be elastic whereas the flowing blood is treated to be Newtonian.Most of the above-mentioned studies characterized blood as a Newtonian fluid and little attention has been given to its suspension nature. It is well known that blood is a suspension of red and white cells together with other small particles in electrolytic aqueous solution of plasma. The non-Newtonian behaviour is attributed to the particulate suspension nature of blood, for which the Newtonian model is inadequate to describe.Micropolar fluid, a non-Newtonian fluid, considers the suspension of naturally buoyant blood particles in a viscous fluid where the individuality of the substructures affects the flow. Charya [5] modelled the steady blood motion as a micropolar fluid to account for the microspin of the particles in a suspension. The study examined the blood flow through a nonsymmetric channel with continuous constricted boundaries. The rheological blood properties together with the shape and size of the stenosis become

SUMMARYThis paper investigates the magnetohydrodynamic (MHD) effects on the blood flow. Rheological properties of blood have been taken into account through the constitutive equations of a micropolar fluid. Unsteady nonlinear differential system is solved numerically by employing finite difference method. Explicit results of axial velocity, flow rate and wall shear stress are obtained and analyzed. It is found that an applied magnetic field reduces the blood flow rate.

Hybrid systems have gained significant attention among researchers and scientists worldwide due to their ability to integrate solar cells and supercapacitors. Subsequently, this has led to rising demands for green energy, miniaturization and mini-electronic wearable devices. These hybrid devices will lead to sustainable energy becoming viable and fossil-fuel-based sources of energy gradually being replaced. A solar photovoltaic (SPV) system is an electronic device that mainly functions to convert photon energy to electrical energy using a solar power source. It has been widely used in developed countries given that they have advanced photovoltaic (PV) technology that reduces dependence on fossil fuels for energy generation. Furthermore, a supercapacitor is an alternative solution for replacing heavy batteries and it is a system with a prominent high power density and a long life cycle. Its unique properties of high capacitance with low voltage limits lead to this highly in-demand material being incorporated into goods and services that are produced by the electrical and electronics industries. It is another option for grid-based power or large batteries. Since supercapacitors have the ability to store huge amounts of energy, they allow for a novel system that integrates supercapacitors with solar cells in which energy generation and energy storage are combined into one system. This paper explores the common materials that are used for solar cells and supercapacitors, the working mechanisms, the effectiveness of the integrated device and the technical challenges that are encountered when refining this device. Hence, this review serves as a guide for choosing the right materials and methods in order to produce an integrated PV solar cell–energy storage device for various applications.

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This paper looked at the numerical investigations of the generalized Newtonian blood flow through a couple of irregular arterial stenoses. The flow is treated to be axisymmetric, with an outline of the stenoses obtained from a three dimensional casting of a mild stenosed artery, so that the flow effectively becomes two-dimensional. The Marker and Cell (MAC) method is developed for the governing unsteady generalized Newtonian equations in staggered grid for viscous incompressible flow in the cylindrical polar co-ordinates system. The derived pressure-Poisson equation was solved using Successive-Over-Relaxation (S.O.R.) method and the pressure-velocity correction formulae have been derived. Computations are performed for the pressure drop, the wall shear stress distribution and the separation region. The presented computations show that in comparison to the corresponding Newtonian model the generalized Newtonian fluid experiences higher pressure drop, lower peak wall shear stress and smaller separation region.

The emergence of COVID-19 affects the world population in many ways, resulting in its own specialised discourse. In addition to providing a source of data for analysis, this discourse has also led to a rethinking of multifarious research methods. This section presents a series of articles by scholars from different parts of the world with macro-and micro-linguistic perspectives, ranging from corpus-based analysis to content analysis studies. At the macro level, these scholars explored ways through which government bodies communicate with the public. Official announcements, parliamentary proceedings and COVID-19-related corpora are examined and a comparative textual analysis between the Malaysian and British governments is provided. At the micro level, the scholars analysed selected corpora with lexical, semantic, and discourse foci and personal posts of short narratives and photos to encapsulate meanings from human life and experience. The main takeaway from these studies is the application of a wide range of methods for different focus and perspectives that may be customised to the researcher's unique context.

Purpose The purpose of this paper is to investigate the relationship between microstructure and varied strain rates towards the mechanical properties and deformation behaviour of Sn-3.0Ag-0.5Cu (SAC305) lead-free solder wire at room temperature. Design/methodology/approach Tensile tests with different strain rates of 1.5 × 10−6, 1.5 × 10−5, 1.5 × 10−4, 1.5 × 10−3, 1.5 × 10−2 and 1.5 × 10−1 s−1 at room temperature of 25°C were carried out on lead-free Sn-3.0Ag-0.5Cu (SAC305) solder wire. Stress-strain curves and mechanical properties such as yield strength, ultimate tensile strength and elongation were determined from the tensile tests. A microstructure analysis was performed by measuring the average grain size and the aspect ratio of the grains. Findings It was observed that higher strain rates showed pronounced dynamic recrystallization on the stress-strain curve. The increase in the strain rates also decreased the grain size of the SAC305 solder wire. It was found that higher strain rates had a pronounced effect on changing the deformation or shape of the grain in a longitudinal direction. An increase in the strain rates increased the tensile strength and ductility of the SAC solder wire. The primary deformation mechanism for strain rates below 1.5 × 10−1 s−1 was grain boundary sliding, whereas the deformation mechanism for strain rates of 1.5 × 10−1 s−1 was diffusional creep. Originality/value Most of the studies regarding the deformation behaviour of lead-free solder usually consider the effect of the elevated temperature. For the current analysis, the effect of the temperature is kept constant at room temperature to analyze the deformation of lead-free solder wire solely because of changes of strain rates, and this is the originality of this paper.