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The yield stress in non-Newtonian fluids is intriguing. Their behaviours and properties transform under different conditions, such as pressure, temperature, concentration, and motile density. Consider a fascinating biological system where temperature differences ignite microorganism activity and production rates, explaining the need for refrigeration and similar processes. As such, the current model breaks free from constant assumptions about fluid properties and mathematically predicts changes in thermal conductivity and mass diffusivity, while viscosity and motile variation are modelled as a composite function of microorganism density and fluid temperature. The bio-convection phenomenon arises when microorganisms self-propel the Eyring–Powell fluid past a three-dimensional Riga plate, driven by stretching velocity. It is an intriguing interplay. To gain deeper insights into the flow model parameters, the weighted residual method (Galerkin approach) is employed to solve the model systems while the findings are presented through tables and graphs. Improving the temperature- and microorganism-dependent variable viscosity significantly decreases the fluid velocities and motile density movement but enhances the temperature and fluid concentration. Conversely, the response of temperature- and microorganism-dependent variable motile density variation energizes the flow momentum and decreases the fluid concentration considerably. For the variable viscosity parameter, ξ 1 ∈ [ 0 , 0.5 ] , the skin drag force and local motile number increase by 22.6% and 5.98%, respectively. Additionally, 100% increment in variable motile density number downsized the skin friction by 289.36% while the local motile density appreciates by 18.90%. In general, the results obtained here are found to be applicable in biophysics, environmental science, and engineering systems.

In this paper, we construct four numerical methods to solve the Burgers–Huxley equation with specified initial and boundary conditions. The four methods are two novel versions of nonstandard finite difference schemes (NSFD1 and NSFD2), explicit exponential finite difference method (EEFDM) and fully implicit exponential finite difference method (FIEFDM). These two classes of numerical methods are popular in the mathematical biology community and it is the first time that such a comparison is made between nonstandard and exponential finite difference schemes. Moreover, the use of both nonstandard and exponential finite difference schemes are very new for the Burgers–Huxley equations. We considered eleven different combination for the parameters controlling diffusion, advection and reaction, which give rise to four different regimes. We obtained stability region or condition for positivity. The performances of the four methods are analysed by computing absolute errors, relative errors, L 1 and L ∞ errors and CPU time.

In this discussion, the influence of carbon nanotubes on fluid flow is explored with the aim of optimizing, facilitating and improving heat transfer and stabilizing the flowing base fluid in modern technology. The current fluid model called Reiner–Philippoff is characterized as pseudo-plastic, dilatant and Newtonian fluid subject to the viscosity variation, making it easy to navigate between fluid rheologies. As a result, the importance of lacing the Reiner–Philippoff fluid flow enhanced by magnetohydrodynamics with single-wall carbon nanotube (SWCNT) and multi-wall carbon nanotube (MWCNT) over a stretching sheet has been investigated. The governing mathematical model of the multi-variable differential equation has been transformed into a one-variable differential equation using a workable similarity transformation. The spectral local linearization method (SLLM) is employed to gain insight into the governing flow parameters, and the results are presented using tables and graphs. Prior to presenting the results of this study, the convergence and accuracy of the SLLM used for gaining insight into the governing flow parameters were established. Among the findings of this study is that the modified magnetic parameter supports the growth of the momentum boundary layer thickness for both SWCNT and MWCNT. The effective Prandtl number decreases the flow resistance more in the SWCNT compared to MWCNT.

The study of biofilm formation is undoubtedly important due to micro-organisms forming a protected mode from the host defense mechanism, which may result in alteration in the host gene transcription and growth rate. A mathematical model of the nonlinear advection–diffusion–reaction equation has been studied for biofilm formation. In this paper, we present two novel non-standard finite difference schemes to obtain an approximate solution to the mathematical model of biofilm formation. One explicit non-standard finite difference scheme is proposed for biomass density equation and one property-conserving scheme for a coupled substrate–biomass system of equations. The nonlinear term in the mathematical model has been handled efficiently. The proposed schemes maintain dynamical consistency (positivity, boundedness, merging of colonies, biofilm annihilation), which is revealed through experimental observation. In order to verify the accuracy and effectiveness of our proposed schemes, we compare our results with those obtained from standard finite difference schemes and earlier known results in the literature. The proposed schemes (NSFD1 and NSFD2) show good performance. The NSFD2 scheme reveals that the processes of biofilm formation and nutritive substrate growth are intricately linked.

This study investigates unsteady, reactive magnetohydrodynamic (MHD) Eyring-Powell fluid in a microchannel, incorporating suction/injection and heat source effects. The governing nonlinear deterministic two-variables differential equations, derived from the principles of conservation of mass, momentum, and species concentration, are transformed into a non-dimensional system using appropriate similarity variables. The coupled equations were solved numerically using the implicit finite difference method (IFDM), which ensures stability and accuracy for stiff systems. Solution errors profiles were presented to give confidence on the numerical solution. The parametric analysis reveal that the fluid parameter significantly retards the flow and temperature profile, while pressure gradient and Grashof number profoundly support the thermal and velocity profiles. Sensitivity analysis is perform to check the impact of the parameters at the walls of the channel. The Grashof number and pressure gradient have the highest influence on the drag force of the fluid near the walls. The viscosity variation and heat source parameters have the highest influence on the heat transfer rate at the left and right walls of the fluid respectively. This work provides valuable insights into the behaviour of non-Newtonian fluids in a microchannel under the combined effects of some thermophysical properties, with potential applications in thin film coating, water filtration/purification systems, and chemical engineering processes.

Purpose The purpose of this paper is to investigate the dynamical behavior of heat and mass transfer of non-Newtonian nanofluid flow through parallel horizontal sheet with heat-dependent thermal conductivity and magnetic field. The effects of thermophoresis and Brownian motion on the Eyring‒Powell nanofluid heat and concentration are also considered. The flow fluid is propelled by squeezing force and constant pressure gradient. The hydromagnetic fluid is induced by periodic time variations. Design/methodology/approach The dimensionless momentum, energy and species balance equations are solved by the spectral local linearization method that is employed to numerically integrate the coupled non-linear differential equations. Findings The response of the fluid flow, temperature and concentration to variational increase in the values of the parameters is graphically presented and discussed accordingly. Originality/value The validity of the method used was checked by comparing it with previous related article.

PurposeIn this paper, we studied the steady flow of a radiative magnetohydrodynamics viscoelastic fluid over an exponentially stretching sheet. This present work incorporated the effects of Soret, Dufour, thermal radiation and chemical reaction.Design/methodology/approachAn appropriate semi-analytical technique called homotopy analysis method (HAM) was used to solve the resulting nonlinear dimensionless boundary value problem, and the method was validated numerically using a finite difference scheme implemented on Maple software.FindingsIt was observed that apart from excellence agreement with the results in literature, the results obtained gave further insights into the behaviour of the system.Originality/valueThe purpose of this research is to investigate heat and mass transfer profiles of a MHD viscoelastic fluid flow over an exponentially stretching sheet in the influence of chemical reaction, thermal radiation and cross-diffusion which are hitherto neglected in previous studies.

The multi-axle crane, a long vehicle with high inertia, has historically struggled with steering efficiency and path-tracking performance. Various control strategies, including Proportional-Integral-Derivative (PID), Linear Quadratic Regulator (LQR), and Model Predictive Control (MPC), have been employed to address these challenges. However, while improving steering efficiency, these strategies have often led to poor path-tracking performance. This work presents a significant advancement in the form of an optimized MPC for improved steering control of the multi-axle crane. A bicycle model of the multi-axle crane was adopted for the work. MPC was designed, and the smell agent optimization technique (SAO) was employed to optimize the steering input weighting factor, which determines the path-tracking performance. This provided an improved and accurate path-tracking performance for different driving speed conditions. Simulation and performance evaluation of the optimized MPC for the steering system were carried out on a curved road path for three different driving speed scenarios (25, 45, and 65 km/h). The results were compared with existing steering systems that utilized the MPC using steering efficiency, dynamic stability, and path-tracking performance. Results obtained showed improvements of 13.88%, 46.02%, and 18.35% in steering efficiency for the three scenarios over the benchmark scheme. Similarly, improvements of 2.29%, 1.03%, and 4.17%, respectively, were achieved in terms of dynamic stability for the three scenarios. For lateral error, improvements of 26.78%, 26.35%, and 27.52% were achieved, while 27.44%, 29.25%, and 28.93% were achieved for the yaw angle error in the three scenarios, respectively. A 3D simulation model for the multi-axle crane was developed in AnyLogic for visual interpretation and validation of the tracking results. These results showed that the developed MPC steering system achieved better steering performance than the existing scheme.

Background Blood transfusion is a vital medical procedure used to treat patients with complications such as severe blood loss, blood disorders, cancers, and those undergoing surgery or experiencing obstetric emergencies. Transfusion transmissible infections (TTIs) pose a significant threat to blood transfusion safety. The prevalence of these infections among blood donors varies widely across regions. This study aims to assess the prevalence and burden of TTIs among prospective blood donors over a three-year period (2020–2022) in Osun State. Method This was a retrospective cross-sectional study spanning a three-year period from January 2020 to December 2022. Data were retrieved from the Uniosun blood bank donor records and only records of prospective blood donors aged 18 to 60 years were included in the study. Data were analysed using the Statistical Package for Social Sciences (SPSS), version 22.0. Descriptive statistics was used to summarize the data and were represented as frequencies and percentages. Results A total of 11,386 blood donor records were retrieved across the three-year period. Above quarter, 25.5% were from 2020, 36.4% from 2021, and 38.1% from 2022. The mean age of the donors was 33.09 ± 8.66 years. More males, 81.2%, constituted the donors, while females represented 18.8%. Most of the donations were family/replacement-based, 90.3% compared to 9.7% of voluntary blood donations. TTIs were prevalent among the age group of 25–34 years. Among all donors tested for the various TTIs, 761 (8.0%) tested positive for Hepatitis B, 358 (4.1%) for Hepatitis C, 235 (2.7%) for Syphilis, 94 (1.1%) for HIV. Over the years, Hepatitis B, recorded the highest prevalence in 2021 with 296 (8.6%), Hepatitis C on the other hand was highest in 2020 at 110 (4.7%), Syphilis recorded the highest prevalence at 80 (3.5%) in 2020 and HIV was highest in 2021 and 2022 with 38 (1.2%) cases. Conclusion This study highlights the persistent burden of TTIs among prospective blood donors in Osun State, Southwest Nigeria, with hepatitis B consistently identified as the most common infection throughout the three-year period assessed. Implementing targeted preventive strategies is a critical step toward reducing transmission and safeguarding blood transfusion safety in the region.

The study explores the novel use of jute nanofibers as environmentally friendly modifiers to enhance the mechanical and thermal properties of waste polypropylene/polystyrene/natural rubber (wPP/PS/NR) ter-blends. It aligns with the sustainable development goal (MDG 7) to ensure environmental sustainability. Nanofiber was produced from jute fiber via a ball milling process after freezing with liquid nitrogen. The produced nanofibers were analyzed using Fourier transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS). Ter-blend, produced via melt blending using two-roll mills, was modified with the nanofibers at different weight percentages (2–10 wt%) at 2 wt% intervals. The modified polymer blends were characterized by their mechanical, thermal, physical, and morphological properties. FTIR revealed the removal of hemicellulose, lignin, and other impurities from the jute fiber due to chemical treatment. DLS analysis revealed an average size distribution of 85.54 nm, for which an intensity and polydispersity index (PDI) of 0.353 was achieved. Additionally, thermogravimetric analysis (TGA) confirmed that the jute nanofibers were thermally stable up to 282 °C. The polymer blends modified with 2 wt% nanofibers had the highest average impact and tensile strength. The percentage water absorption (%WA) showed that sp10% absorbed the highest amount of water after 24 h. The weight loss of the modified blend at various temperatures increased with the addition of nanofibers. Scanning electron microscopy (SEM) revealed cracks, voids, and blend separation as the amount of jute nanofibers increased. Dynamic mechanical analysis (DMA) revealed that the T g of the modified blend improved, while the loss factor improved greatly by 43%, but the storage and loss moduli remained unchanged.