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Abstract This study investigates the impact of $$\mathrm {Al_2O_3}$$ Al 2 O 3 particle volume fraction and distribution on the deformation and damage of particle-reinforced metal matrix composites, particularly in the context of functionally graded metal matrix composites. In this study, a two-dimensional nonlinear random microstructure-based finite element modeling approach implemented in ABAQUS/Explicit with a Python-generated script to analyze the deformation and damage mechanisms in $$\mathrm{AA6061\mbox{-}T6/Al_2O_{3}}$$ AA 6061 - T 6 / Al 2 O 3 composites. The plastic deformation and ductile cracking of the matrix are captured using the Gurson–Tvergaard–Needleman model, whereas particle fracture is modelled using the Johnson–Holmquist II model. Matrix-particle interface decohesion is simulated using the surface-based cohesive zone method. The findings reveal that functionally graded metal matrix composites exhibit higher hardness values ( $$\textrm{HRB}$$ HRB ) than traditional metal matrix composites. The results highlight the importance of functionally graded metal matrix composites. Functionally graded metal matrix composites with a Gaussian distribution and a particle volume fraction of 10% achieve $$\textrm{HRB}$$ HRB values comparable to particle-reinforced metal matrix composites with a particle volume fraction of 20%, with only a 2% difference in $$\textrm{HRB}$$ HRB . Thus, $$\textrm{HRB}$$ HRB can be improved significantly by employing a low particle volume fraction and incorporating a Gaussian distribution across the material thickness. Furthermore, functionally graded metal matrix composites with a Gaussian distribution exhibit higher $$\textrm{HRB}$$ HRB values and better agreement with experimental distribution functions when compared to those with a power-law distribution.

Background Acute kidney injury (AKI) in the ICU is one of the life-threatening situations that may need renal replacement therapy (RRT). Survival benefit of early initiation of RRT is still not proven. There is still a debate whether early or late RRT significantly affects morbidity and mortality.Methods This is a randomized controlled trial (RCT) that was conducted on 94 critically ill subjects with stage 2 AKI, according to KDIGO classification, who were on invasive mechanical ventilation. Recruited subjects were selected only if they failed to respond to furosemide stress test after volume status optimization. Subjects were randomly assigned into two groups according to timing of RRT initiation. In the early group, RRT was initiated without the presence of urgent indications for hemodialysis, whereas in the late group, RRT was implemented only in the presence of one or more of urgent indications such as severe metabolic acidosis or hyperkalemia. Primary outcomes of the study were ICU mortality and length of stay. Secondary outcomes included recovery of renal function in addition to duration of mechanical ventilation.Results There was no statistically significant difference in the primary outcomes, namely ICU mortality and ICU length of stay. About 51.1% of the subjects survived in the early RRT group, whereas 46.8% survived in the late group (p = .680). Although duration of mechanical ventilationwas not significantly different (p = .486), recovery of renal functionand less dependency on RRT after discharge, were significantly higher in the early RRT group (p = < .001).Conclusion Even after choosing AKI patients who failed to respond to furosemide stress test, timing of RRT initiation did not affect survival, ICU length of stay or duration of mechanical ventilation. However, early RRT may have positive effect on RRF for survived patients.

This work aims to use mathematical modeling to investigate the mechanics of heat and mass transport in dissipative Casson nanofluid flows over a linear rough sheet. This study considers various elements such as thermal radiation, magnetic fields, heat generation, the varied properties of porous media, and the thermophoretic impact. Besides that, it looks into the variations in viscosity, diffusivity, and thermal conductivity, as well as the energy dissipation from viscous internal friction and fluid temperature modifications. The method involves coming up with and changing the boundary layer equations into a group of linked nonlinear ordinary differential equations that use variables that do not have any dimensions. The foundation of the solution strategy for these equations is the Hermite collocation method (HCM), which is renowned for its precision and adaptability. It offers an organized approach to solving the complex differential equations, allowing for accurate numerical solutions. The use of graphical representations ensures thorough data analysis and clarity, while also providing insightful information about the computed outcomes. The code validation method uses numerical comparisons with recent research to confirm the algorithm’s accuracy and dependability, as well as its resilience in comparison to the existing literature. Important conclusions from the study show that thermal boundary layers and nanofluid velocity decrease with increases in the porosity parameter, slip parameter, and magnetic field parameter.

This study aims to thoroughly investigate the flow behaviour of a Reiner–Philippoff nanofluid over a nonlinearly stretching sheet, with a particular focus on the effects of viscous dissipation. The research delves into the complex interactions within the nanofluid, assessing how viscous dissipation influences heat and mass transfer rates. To model the nanofluid flow, the Darcy–Forchheimer model was employed alongside slip velocity effects. Thermal radiation was incorporated to control heat transfer, while activation energy was considered for mass transfer regulation. The Buongiorno hypothesis was used to account for thermophoresis and Brownian motion in the governing equations. Following appropriate transformations, the nonlinear ordinary differential equations were formulated and solved using the shooting method. Key parameters such as skin friction, Nusselt number, and Sherwood number were analysed in tabular form, while graphical representations highlighted the impact of variables like concentration, velocity, and temperature. The study found that considering slip velocity in combination with the Darcy–Forchheimer model significantly enhances mass transfer. A comparison with existing data demonstrated the consistency of the results. This research holds relevance for applications in acid rain, pollution migration, groundwater treatment, and related environmental processes. It has been noted that raising the porosity parameter and the Forchheimer number causes the temperature and concentration levels to drop while boosting the fluid’s velocity.

Abstract This paper presents a numerical investigation of the flow of a non-Newtonian tangent hyperbolic nanofluid over a nonlinearly stretched surface, taking into account factors such as thermal radiation, prescribed surface temperature, and a chemical reaction mechanism. Furthermore, the analysis includes the consideration of both viscous dissipation and the influence of a magnetic field within a Darcy porous medium. A mathematical framework for addressing the issue, rooted in the principles of conserving momentum, energy, and mass. The MATHEMATICA tools were employed to apply the shooting technique in order to solve the modeled equations describing the temperature, velocity, and concentration fields of the proposed physical system. Graphs are used to illustrate how certain key parameters affect the profiles of concentration, velocity, and temperature. Data tables are utilized to display information pertaining to the local Nusselt number, local Sherwood number, and local skin friction coefficient. The present results have been confirmed through a comparison with previously published findings. This research holds significant importance as it focuses on the extensive utilization of tangent hyperbolic nanofluids in cooling electronic components that produce substantial heat during their operation. The observed pattern indicates that as the local Weisbsenberg number, magnetic number, local porous parameter, and power law index increase, there is a reduction in the boundary layer thickness. Conversely, in the instances of concentration and temperature distributions, an escalation in these parameters leads to an expansion of the boundary layer thickness.

Abstract The purpose of this research was to examine the viability of applying a flawless polyaniline coating on steel spearheads to preserve them and protect them from corrosion. The spearpoints, thought to be archaeologically significant, were acquired from the Military Museum in Al-Qala, Egypt. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy were used to characterize the spearheads chemical composition and microstructure (EDX). The spearheads were determined to be constructed of steel and to have a coating of ferric oxide and other corrosion products on their exteriors. After that, a flawless polyaniline coating was electrochemically deposited onto the spearpoints in a way that was both quick and cheap. Many types of corrosion tests, such as electrochemical impedance spectroscopy and potentiodynamic polarization (PDP) readings, were used to determine the coating’s effectiveness. The steel spearheads’ findings revealed a significant improvement in their resistance to corrosion after being coated with flawless polyaniline. The coating served as a barrier, blocking out water and other corrosive substances and slowing the buildup of corrosion byproducts on the spearpoints. In conclusion, our research shows that a flawless polyaniline coating may be an effective anti-corrosion treatment for ancient steel artifacts. The approach is straightforward, cheap, and readily scalable for massive conservation efforts.

Abstract The main aim of this paper is to investigate the effect of non-uniform heat generation and viscous dissipation on the boundary layer flow of a power-law nanofluid over a nonlinear stretching sheet. Within the thermal domain, the analysis considers both thermal radiation and variable thermal conductivity. Through the use of similarity transformations, the governing boundary layer equations are transformed into a system of ODEs. The spectral collocation method (SCM) with shifted Vieta-Lucas polynomials (VLPs) is implemented to give an approximate expression for the derivatives and then use it to numerically solve the proposed system of equations. By employing this technique, the system of ODEs is converted into a system of nonlinear algebraic equations. The dimensionless temperature, concentration, and velocity are graphically presented and analyzed for various values of the relevant governing parameters. Through the presented graphical solutions, we can see that the main outcomes indicate that an increase in the power law index, thermal conductivity parameter, and radiation parameter leads to a noticeable decrease in the local Nusselt number, with reductions of around 0.05 percent, 0.23 percent, and 0.11 percent, respectively. In contrast, the Prandtl parameter demonstrates an opposing effect, elevating the local Nusselt number by about 0.1 percent. We validated the accuracy of the numerical solutions by comparing them in some special cases with existing literature.

This study aims to explore the characteristics of tangent hyperbolic fluid flow along a stretching sheet. The sheet has suction or injection influences and is located inside a porous medium. The research inspects the flow and heat transfer (FHT) properties, taking into account the presence of a velocity slip condition. The flow of non-Newtonian magnetohydrodynamic fluid caused by a porous stretching sheet, taking into account thermal radiation and heat generation, has a wide range of engineering applications. These applications involve chemical reactors, energy distribution, storage of solar energy, and filtration processes. Mathematically, the flow problem is expressed as a collection of nonlinear partial differential equations. To numerically solve the resulting ODEs, the finite difference approach (FDM) is successfully used. Tables and graphs are used to display the various output values related to the hyperbolic tangent fluid. Among the different output values that appear are velocity and temperature. Significant observations from the study indicate that an increase in the power-law index, slip velocity parameter, porosity parameter, and magnetic number results in a decrease in the fluid's velocity and an increase in temperature. The completed comparison analysis shows a sizable degree of agreement with the earlier investigation.

Recent advancements in thermal engineering have led to the development of stable thermal properties and practical applications for nanofluid flow. Consequently, this study aims to explore the heat and mass transfer characteristics of a non-Newtonian Maxwell nanofluid when it comes into contact with a stretched surface containing porous features that allow for fluid suction velocity. Additionally, the research takes into account how the Soret and Dufour effects impact the processes of heat and mass transfer. A less-explored aspect of research in this field relates to the velocity slip boundary conditions when nanofluids with changing viscosity are involved. Additionally, the model employed in this study illustrates the influence of both viscous dissipation and variable thermal conductivity on the processes of heat and mass transfer. The mathematical flow model is described by nonlinear partial differential equations, which are subsequently transformed into non-dimensional ordinary differential equations. The resulting system is then solved numerically using the shooting method. This study visually examines the impact of physical variables on temperature, flow characteristics, and concentration patterns. Furthermore, it provides graphical representations of estimated values for the skin friction coefficient, Sherwood numbers, and local Nusselt numbers, which are also organized in tables for analysis. In conclusion, by comparing our data with previous results, we confirm the accuracy and reliability of the proposed method. A significant discovery is that the nanofluid velocity decreases as the Maxwell, porous, and slip velocity parameters are increased. Furthermore, the nanofluid concentration rises when the thermophoresis and viscosity parameters increase.

Abstract A green, fast and robust solvent-free chromatographic method has been developed for concomitant analysis of ciprofloxacin HCl and metronidazole in bulk powder as well as in dosage form using levofloxacin as internal standard (I.S.). Two different designs including fractional factorial (FFD) and Box–Behnken (BBD) designs were implemented for screening and optimization steps, respectively. The optimum chromatographic separation was accomplished using mobile phase composed of 0.13 M sodium dodecyl sulfate and 0.02 M Birij-35 solution adjusted to pH 2.5 using phosphoric acid at a flow rate of 1.3 mL/min and column oven temperature of 40 °C. Chromatographic analysis was performed on X-Bridge (150 mm × 4.6 mm, 5 μm) column with UV detection at 280 nm. A linear response was acquired over the range of 0.4–50 μg/mL for both drugs. The developed method was applied for quantitation of cited drugs in commercially available tablet with mean percent recovery ± SD of 99.45 ± 0.72 and 100.13 ± 0.81 for metronidazole and ciprofloxacin respectively. The method was proven to be green as evaluated by three greenness assessment tools. The run time was 8 min, thus saving time and reagent.

Abstract The novelty and motivation of this research can be emphasized by examining how the heat transfer mechanism of a non-Newtonian Powell-Eyring fluid, which flows because of a stretched sheet, is affected by factors like viscous dissipation, the slip velocity phenomenon, and Joule heating. In addition, the investigation delves into the heat transfer behavior of the fluid flow when it comes into contact with a convectively heated stretched surface that is influenced by varying fluid properties. This analysis also takes into account the influence of changing fluid characteristics and the presence of magnetic field. The numerical solutions of modelled equations that governing the problem are detected using the shooting technique. Also, in order to confirm the validity of the present investigation, a proper comparison with certain published works as a particular case of the present model is presented, and a perfect agreement is noted. With the use of diagrams and tables, the flow problem’s effective parameters are thoroughly discussed. Likewise, through a tabular representation, the values of the local Nusselt number and the skin-friction coefficient are computed and analyzed. Many significant conclusions can be drawn from numerical results. Most importantly, the local Nusselt number rises monotonically with both the surface convection parameter and the slip velocity parameter, but the local skin-friction coefficient has the opposite trend. The results indicate that the nanofluid temperature is enhanced by factors such as the surface convection parameter, magnetic field, and viscous dissipation. On the other hand, the slip velocity phenomenon leads to the opposite effect.

Abstract This paper investigates the cavity–magnon steering and qubit–qubit steering of a hybrid quantum system consisting of a single-mode magnon, a two-qubit state, and a single-mode cavity field in the presence of their damping rates. The temporal wave vector of the system is obtained for the initial maximally entangled two-qubit state and initial vacuum state of the magnon and cavity modes. Additionally, the mathematical inequalities for obtaining the cavity–magnon steering and qubit–qubit steering are introduced. The findings reveal that steering between the magnon and cavity is asymmetric, while steering between the two qubits is symmetric in our system. Increasing the atom–field coupling improves steering from magnon to field, while reducing steering between the two qubits. Moreover, increasing magnon–field coupling enhances and elevates the lower bounds of qubit–qubit steering. Further, adding the damping rates causes deterioration of the cavity–magnon steering and qubit–qubit steering. However, the steering persistence is slightly greater when damping originates from the cavity field rather than the magnon modes based on the coupling parameters.

Abstract The objective of this article is to investigate how the properties of a non-Newtonian Williamson nanofluid flow, which occurs due to an exponential stretching sheet placed in a porous medium, are influenced by heat generation, viscous dissipation, and magnetic field. This study focuses on analyzing the heat transfer process by considering the impact of temperature on the thermal conductivity and viscosity of Williamson nanofluids. Additionally, the research significantly contributes by investigating the flow characteristics of these nanofluids when influenced by slip velocity. Using the spectral collocation method (SCM), the equations that describe the current problem are transformed into a collection of ordinary differential equations and then solved. The SCM proposed here basically depends on the properties of the Appell-type Changhee polynomials (ACPs). First, with the aid of ACPs, we give an approximate formula of the derivatives for the approximated functions. Through this procedure, the provided model is transformed into a nonlinear set of algebraic equations. Physical factors of interest, such as skin friction, the Nusselt number, and the Sherwood number, are explained using tabular expressions. Data are displayed as graphs for the nanofluid’s velocity, temperature, and concentration. The primary findings showed that increasing the Williamson, magnetic, thermal conductivity, and Brownian parameters significantly improves the thermal field. Finally, testing the suggested method with specific cases from some past literature-based publications reveal a good degree of agreement.

Abstract Transcatheter aortic valve replacement (TAVR) is the gold standard treatment for patients with symptomatic aortic stenosis. The utility of existing risk prediction tools for in-hospital mortality post-TAVR is limited due to two major factors: (a) the predictive accuracy of these tools is insufficient when only preoperative variables are incorporated, and (b) their efficacy is also compromised when solely postoperative variables are employed, subsequently constraining their application in preoperative decision support. This study examined whether statistical/machine learning models trained with solely preoperative information encoded in the administrative National Inpatient Sample database could accurately predict in-hospital outcomes (death/survival) post-TAVR. Fifteen popular binary classification methods were used to model in-hospital survival/death. These methods were evaluated using multiple classification metrics, including the area under the receiver operating characteristic curve (AUC). By analyzing 54,739 TAVRs, the top five classification models had an AUC ≥ 0.80 for two sampling scenarios: random, consistent with previous studies, and time-based, which assessed whether the models could be deployed without frequent retraining. Given the minimal practical differences in the predictive accuracies of the top five models, the L2 regularized logistic regression model is recommended as the best overall model since it is computationally efficient and easy to interpret.

Objectives: Ducks suffer a huge economic loss as a result of infections with Pasteurella multocida and Riemerella anatipestifer, which cause high morbidity and mortality. Because these patho¬gens induce similar clinical symptoms when coinfections occur, it is very difficult to differentiate between them based just on clinical signs. Hence, these major pathogens must be quickly and accurately detected. Materials and Methods: A total of 104 birds ranging from 2 days to 4 weeks old were collected from Egyptian farms, and the outcomes were compared statistically. Conventional cultural iden¬tification procedures and a direct multiplex polymerase chain reaction assay were utilized to recognize both pathogens in a single tube reaction simultaneously. Then, the obtained isolates were characterized phenotypically and genotypically. Results: Clinical signs appear at 2–4 weeks of age with respiratory distress (dyspnea), white fluid feces, and stunting. The scrutinized data demonstrated a significantly higher detection rate by PCR directly compared to classical culture procedures. Pasteurella multocida was detected only by PCR. The disc diffusion technique against ten antibiotics showed absolute susceptibilities to amik¬acin, doxycycline, and florfenicol. High levels of beta-lactam resistance were observed. Riemerella anatipestifer isolates were screened for pathogenicity and plasmid-borne blaTEM genes. All six isolates harbored five virulence genes: aspC, RA46, m28, pstS, and Nlp/P60. Moreover, blaTEM was identified into four isolates and deposited to GenBank with accession numbers OP347083, OP347084, OP347085, and OP347086. Conclusion: These results suggest advanced PCR assays can be applied to the field for rapid and valuable diagnosis of two significant pathogens and focus on the worth of ducks in the propaga¬tion of transferable antibiotic resistance genes into the environment. [J Adv Vet Anim Res 2023; 10(2.000): 211-221]

Abstract A green, robust and fast stability indicating chromatographic method has been developed for concomitant analysis of fluorescein sodium and benoxinate hydrochloride in the presence of their degradation products within four minutes. Two different designs including fractional factorial and Box–Behnken designs were implemented for screening and optimization steps, respectively. The optimum chromatographic analysis was achieved using a mixture of isopropanol and 20 mM potassium dihydrogen phosphate solution (pH 3.0) in the ratio 27:73 as mobile phase. The flow rate was 1.5 mL/min and column oven temperature was 40 °C. Chromatographic analysis was performed on Eclipse plus C18 (100 mm × 4.6 mm × 3.5 μm) column with DAD detector set at 220 nm. A linear response was acquired over the range of 2.5–60 μg/mL and 1–50 μg/mL for benoxinate and fluorescein respectively. Stress degradation studies were executed under acidic, basic, and oxidative stress conditions. The method was implemented for quantitation of cited drugs in ophthalmic solution with mean percent recovery ± SD of 99.21 ± 0.74 and 99.88 ± 0.58 for benoxinate and fluorescein respectively. The proposed method is more rapid and eco-friendly compared to the reported chromatographic methods for determination of cited drugs.

Abstract Background Inserting IUDs during cesarean section reduces the need for more manipulation and discomfort. The current conventional manual technique for IUD insertion during cesarean section is not standardized with many modifications and high rates of expulsion, displacement, missed threads, and discontinuation. This study aims to find a standard technique for IUD insertion during cesarean section with the least possible problems, especially displacement and missed threads. Methods A randomized controlled study was conducted at Kasr Al-Ainy Maternity Hospital, Cairo University, Egypt. The study was performed over 12 months, from September 2020 to September 2021. Two groups of patients were selected; each group included 420 patients with a desire for IUD insertion during cesarean section. Group (A) (Control group) was subjected to a post-placental intrauterine device (Copper T380) during cesarean section using a conventional manual method; Group (B) (Study group): the IUD (Copper T380) was placed at the top of the uterine fundus using a new technique (intra-cesarean post placental introducer withdrawal IUD insertion technique). Results There was a significant statistical difference between the two groups regarding displacement of the IUDs at the end of puerperium, at 6 months, non-visibility of IUD threads, and continuation of use with p-value

The objective of this paper is to examine the flow of a non-Newtonian Maxwell fluid induced by a permeable stretching sheet in motion within a porous medium. The research incorporates the Cattaneo-Christov heat flux model to study the heat transfer process. The utilization of the Cattaneo-Christov heat flux approach becomes relevant in scenarios involving materials with high thermal conductivity or during short time intervals. Consequently, the current investigation holds significant importance. It is assumed that the viscosity of the Maxwell fluid changes exponentially as the temperature changes. The modeling of the physical phenomena being investigated takes into account the effects of a magnetic field, thermal radiation, velocity, and thermal slip conditions. In this study, the viscous dissipation phenomenon is taken into account because it can have notable impacts on the temperature and viscosity of the fluid, and is known to play a crucial role in fluid flow phenomena. The equations developed to model fluid flow are transformed into nonlinear ordinary differential equations through the use of appropriate similarity transformations. The focus of the research revolves around investigating the numerical solution of ordinary differential equations accompanied by boundary conditions using the shooting technique. The findings are then showcased via tables and graphs and scrutinized in order to arrive at conclusions. Furthermore, the precision of the present findings was evaluated by contrasting the heat transfer rate with outcomes that were previously published. Based on the obtained outcomes, it can be concluded that both the Eckert number and thermal radiation have a comparable enhancing influence, whereas the thermal relaxation parameter and thermal slip parameter exhibit opposing effects.

The research introduces a novel aspect by focusing on the examination of a Casson nanofluid flowing over a nonlinear stretching sheet within a porous medium. The primary aim of this study is to explore the heat-mass transfer phenomena in this particular scenario. Notably, the Casson fluid employed in this investigation contains nanoparticles and is subjected to the effect of a constant magnetic field (MF). Furthermore, the study takes into consideration the effects of slip in velocity, concentration, and temperature on the flow of nanofluid over a nonlinear stretching surface. The research takes into account heat generation and viscous dissipation, and it solves the descriptive equations using similarity transformations and the finite difference approach. Heat generation and viscous dissipation play a crucial role in influencing the heat transfer process. The study illustrates and examines the effects of several parameters on the profiles of velocity, concentration and temperature. For various incorporated factors indicated in the provided problem statements, the Sherwood number, Nusselt number, and skin friction coefficient are analyzed and evaluated. Temperature augmentation occurs when the heat-generating parameter is increased. Variable thermal conductivity and temperature are directly correlated, as well. Furthermore, by contrasting the acquired results with published findings in a particular limited case, the accuracy of the current technique is shown. The notable results reveal that as the magnetic number, porous parameter, and stretching parameter increase, there is a decrease in both heat-mass transfer rates.

The research aims to investigate the motion of a two-dimensional magnetohydrodynamic fluid with hyperbolic tangent properties, combined with nanoparticles, as it approaches a stretching sheet. The flow of nanofluid is hypothesized to be a consequence of the stretching of an elastic sheet within a porous medium. The stretching sheet has a rough surface, and this allows for the consideration of the slip velocity phenomenon. Mathematically modeling the analysis of current flow results in a set of nonlinear partial differential equations, which can be simplified into ordinary differential equations using appropriate dimensionless transformations. Subsequently, the resulting equations are solved utilizing the shooting technique. A comprehensive analysis is conducted to interpret in detail how the various physical parameters influence concentration, velocity, and temperature. Moreover, local Sherwood number, local skin friction, and local Nusselt number are calculated and presented in a tabular form for further analysis. The precision of the computed results is further confirmed by comparing the obtained findings with the body of available literature. It is noted that there is a clear similarity between the current results and the provided data. This demonstrate that the suggested numerical procedure is accurate. Quantitative findings reveal that augmenting the porous parameter, slip velocity parameter, power law index, and magnetic parameter leads to a reduction in the nanofluid velocity. However, a contrasting pattern emerges in the case of the temperature profile. Further, through a comprehensive examination, it has been revealed that the slip velocity phenomenon significantly influences the dynamics of nanofluid flow.

Recently, there has been considerable attention given to a sophisticated fluid system known as the Maxwell nanofluid, which incorporates chemical reactions and the Cattaneo-Christov heat flux. This system has garnered significant interest due to its potential significance in various fields, including heat transfer, chemical engineering, and nanotechnology. Therefore, this numerical investigation proposes a new model for the steady two-dimensional flow of a homogeneous Maxwell nanofluid towards a vertical stretching sheet that incorporated within a porous medium, aimed at revealing the fluid's dynamic and thermal characteristics. The model is specifically tailored for nanofluids and includes thermal radiation, chemical reactions and slip conditions. It is presumed that the viscosity of the Maxwell nanofluid changes with variations in temperature. The governing partial differential equations and corresponding boundary conditions for the nanofluid flow problem are derived in a suitable manner, based on physically valid assumptions and validated experimental correlations. MATHEMATICA software is used to perform arithmetic simulations of the energy, mass concentration, and momentum equations. The simulations are carried out using the fourth-order Runge-Kutta technique in conjunction with the shooting method. Numerical and visual techniques are utilized to examine how the physical parameters that control the model influence it. Subsequent to evaluating our data against prior findings, the reliability and precision of the proposed method are verified. The findings show that the nanofluid's velocity detracts when the slip velocity, Maxwell parameter, magnetic forces, viscosity parameter, and porous parameter rise. The temperature field, which is affected by these parameters, shows the opposite tendency, on the other hand. In addition, the suction parameter application results in a drop in the concentration, temperature, and velocity of the nanofluid.

Analysis of a steady flow of a viscous Casson fluid subject to Ohmic dissipation and an induced magnetic field is the main goal here. Through a stretched vertical sheet, the flow is managed. The energy equation is explained in a thermodynamical system along with Ohmic heating. By making the assumption that the viscosity and thermal conductivity are temperature-dependent as described here, an accurate assessment of the heat transfer rate may be carried out. Our research also addresses the effect of slip velocity. There are many applications for thermal flow fields subject to limited spaces and heated walls, including electronic cooling systems, furnaces, cooling towers, and thermal individualities in buildings and rooms, to highlight a few. The governing equations of the current model are generated mathematically in the form of partial differential equations by applying the boundary layer approximations along with these assumptions. Through appropriate transformations, a nonlinear system of differential equations is produced. The approximate solution is then obtained by using the Chebyshev spectral collocation method. The proposed problem is reduced to a nonlinear system of algebraic equations with the help of the properties of Chebyshev polynomials of the third-kind. Diagrams are therefore used to illustrate the significant impact of all controlling parameters on the fluid flow. Further, the local Nusselt number and the skin-friction coefficients’ numerical values are also computed and examined. Results show that the Casson fluid motion is strengthened by the electric and mixed convection characteristics, whereas the magnetic, the slip velocity and viscosity parameters impede the flow motion. Also, the distribution of temperature is amplified by a larger Eckert number.

In this study, we investigated the heat and mass transport properties of a non-Newtonian Casson-Williamson nanofluid flow. We explore the effect of viscous dissipation and the velocity slip boundary condition on the mechanism of heat and mass transfer due to a stretching sheet which embedded in a porous medium with heat generation under the influence of both thermal radiation and a uniform magnetic field. All physicochemical characteristics of Casson-Williamson nanofluid are considered to be constant. The nanofluid concentration is investigated under chemical repercussions as a result of the movement of the nanofluid particles. This study assumes that there is no suction (solid wall). A set of nonlinear partial differential equations with boundary conditions are used to mathematically model this physical problem. The numerical solution for the differential equations with the related boundary conditions was illuminated using the Runge–Kutta approach in conjunction with the shooting technique. The numerical examination is then pictorial displayed to show the impact of various governing factors on velocity, temperature, and concentration. The non-Newtonian nanofluid has a faster velocity in the absence of a magnetic field than in the presence of it, although the temperature field has the opposite trend. Further, the skin-friction coefficient increased as the porosity parameter increased, whereas the rate of heat transfer dropped.

Abstract This work studied comparison of the mechanical and barrier resistance properties between different structures of three multilayers polymeric coating on each side of the steel coupons. Epoxy filled with 1 wt%, 2 wt%, and 3 wt% micron or nano-sized alumina (Al2O3) particles represented the coating layers to steel on both sides. Barrier resistance was performed by immersing the coated steel specimens in salt solution and in a citric acid medium. Adding alumina (Al2O3) particles in micron and nano size to epoxy coatings improved the barrier resistance, tensile, and hardness under dry and wet conditions as compared to pure epoxy coating. Further increases in Al2O3 micro/nanoparticles cause deterioration in tensile strength and barrier resistance. The steel lined with epoxy filled with 1 wt% Al2O3 nanoparticles has a maximum tensile strength of 299.5 MPa and 280.9 MPa under dry and wet conditions, respectively. However, the steel lined with epoxy filled with 1 wt% Al2O3 microparticles has a tensile strength of 296.5 MPa and 275.4 MPa under dry and wet conditions, respectively. Good properties were observed with stepwise graded micro/nanocomposite coatings. The steel lined with epoxy filled with 3 wt% Al2O3 nanoparticles has maximum hardness of 46 HV and 40 HV under dry and wet conditions, respectively.

A numerical analysis of the incompressible two-dimensional flow of a non-Newtonian Williamson fluid is offered by expanding the sheet embedded in a porous medium and combining it with the Cattaneo-Christov model. Additionally, it is considered that the thermal conductivity and fluid viscosity both change as a linear function of temperature and an exponential function, respectively. The velocity, temperature and concentration field are all affected by thermal radiation, viscous dissipation, fluid variable properties, chemical reactions, and the slip velocity phenomenon. When the appropriate variables are employed, a system of non-linear, non-dimensional parameters emerges. The shooting method is used to numerically address this system. To better comprehend the impact of dimensionless parameters on dimensionless velocity, concentration, and temperature profiles, physical descriptions are prepared and justified using graphical representations. The values of the local skin-friction coefficient, the rate of heat transfer, and the rate of mass transfer are also investigated using tables. The behavior of changing fluid properties, on the other hand, establishes the link between Williamson fluid flow and the rate of heat mass transfer. According to the results, increasing the slip velocity and viscosity factors lowers both the Nusselt number and the Sherwood number. Also, due to an increase in Deborah number and the chemical reaction parameter, the temperature profiles decrease.

This research is innovative in that it investigates the flow of a Maxwell nanofluid that exhibits non-Newtonian behavior over a horizontally stretching sheet, using a boundary layer medium and taking into account the Cattaneo-Christov model. Thermal radiation and the effects of fluctuating nanofluid conductivity with temperature on a stretched, linearly impermeable surface are also taken into account. The main topic of the research is the situation when the viscosity of the nanofluid changes with temperature. The group of differential equations that drives our proposed problem is highly nonlinear and is numerically solved by the shooting method. The results are given in accordance with graphs of a number of newly influential parameters against velocity, temperature, and concentration fields. Skin friction coefficient, Nusselt number, and Sherwood number, which are coupled to velocity, temperature, and concentration distributions recorded in tables, have been provided for a range of values of the regulating physical emergent factors. Some significant findings suggest that increasing the magnetic number, viscosity parameter, and Maxwell number results in decreased motion of the nanofluid, while concentration and temperature distribution increase. After completing our computations, we organized the findings and compared them to previous research. Our observation is that the proposed method's accuracy and reliability have been proven.

Abstract Copper and copper alloys are used in industrial applications and food contact surfaces due to their desirable properties; copper metal matrix composites have been exciting researchers' attention in recent years since they can offer many valuable characteristics. The present study investigated the effects of the TiO2 nanoparticles addition with different weight percent on the hardness and corrosion behavior of copper nanocomposites. The powder metallurgy method was used to fabricate the Cu/TiO2 reinforced with different weight fractions of TiO2 nano particles up to 12 wt.%. The corrosion behavior of fabricated specimens is evaluated using potentiodynamic polarization curves and electrochemical impedance spectroscopy in different solutions. These solutions were 3.5wt.% NaCl, 0.5 NaOH and 0.5 M H2SO4 reflected different pH. The results showed that the addition of TiO2 nano particles improves pure copper's hardness. The hardness of pure copper increased from 53 to 91 HV by adding 12 wt.% TiO2. The corrosion current density (Icorr) of copper nanocomposites test specimens was higher than Icorr of pure copper in all test solutions. As TiO2 nano particles increase, the corrosion resistance of Cu nano composites decreased. All test specimens exhibited little corrosion current density in 3.5 wt.% NaCl solution as compared with other test solutions.

This research focuses on the mechanical behavior of cost-effective novel hybrid fiber metal laminates (FMLs) based on aluminum (Al) 1050 alloy and jute/glass fiber reinforced epoxy composites. The effects of the stacking sequence and relative fiber amounts have been investigated. Specimens were fabricated using hand lay-up technique followed by compression molding. Results revealed that the reinforcement hybridization can potentially improve the tensile and flexural properties of FMLs based on jute fabric. The flexural strength of FMLs based on jute fabric has been improved when partial laminas from jute/epoxy laminate are replaced by glass/epoxy laminas. Also, it is realized that the incorporation of high strength fibers to the composite core leads to higher tensile properties but lower flexural resistance.

Newcastle disease virus (NDV) genotype VII is incriminated in the currently circulating NDV outbreaks in the Middle East region. In this study, evaluation of different vaccination regimes including genetically-matched or mismatched vaccines to the currently circulating field virulent NDV (vNDV) genotype VII was performed. One-day-old Arbor Acres broiler chicks were divided into nine groups; groups 1 to 3 were vaccinated with live or inactivated genetic-mismatched vaccines (genotype II) or both of them. Groups 4 to 6 were vaccinated with either live or inactivated genetic-matched vaccine to vNDV genotype VII or combination of them. Group (Gp) 7 was vaccinated with a combination of inactivated genetic-matched and live genetic-mismatched vaccines to vNDV genotype VII while groups 8 and 9 were kept as control non-vaccinated. The groups that received a combination of live and inactivated vaccines from either genetically-matched or mismatched origins had the highest serological responses and protection against mortality which was 100%. The two groups received a combination of inactivated genetic matched vaccine and live vaccines of either genetic-matched or mismatched origins had the lowest clinical index and were nearly completely protected against vNDV clinical signs. The virus tracheal and cloacal shedding titers and number of shedders were significantly reduced or nearly neglicable in the instance of application of inactivated genetic-matched vaccine to the challenge virus either alone or boosted with live genetic-matched or mismatched vaccine. In consistent inactivated genetic-matched vaccine inhibited the transmissibility of the challenged virus to contacted birds. We concluded from our results that application of NDV vaccination regimes included a combination of inactivated NDV genotype VII vaccine and live vaccine regardless of its genotype provides better clinical protection and minimize virus shedding and subsequently decrease transmissibility and virus load to the surrounding environment.

This work aimed to present the influence of the magnetic field and Ohmic dissipation on the non-Newtonian Casson fluid on a vertical stretched sheet to numerically solve the problem. Here, the variable thermal conductivity is taken as a linear function of temperature. Electric fields, thermal slip, and viscous dissipation effects are taken into consideration. A collection of physical conditions on the sheet’s enclosing wall and the momentum and heat transport processes are expressed as partial differential equations (PDEs). Some of the similarity transformations are used to convert the collection of PDE into a system of ordinary differential equations. This system is numerically treated by implementing the Vieta-Lucas spectral collocation method. Some observations are made for the investigation of method convergence. The effect of some different parameters on the velocity and temperature profiles is graphically represented. Additionally, this area of study has significant practical applications in a variety of industries, including paper production, thermal power generation, nuclear reactors, cooling of metallic sheets, glass fiber, and lubrication.

The present study explores the effects of viscous dissipation, the thermal dependent conductivity and the thermal dependent viscosity on the steady motion of a Powell-Eyring fluid over a stratified stretching sheet which embedded in a porous medium. The fact that the nature of non-Newtonian flows problems are highly nonlinear equations has been taken into consideration here and this was the motive objective to determine numerical solutions. So, the emphasis is on the methodology adopted for obtaining numerical solutions that yielded after employing the Chebyshev spectral method. The temperature distributions and the velocity components are evaluated by solving numerically the boundary value problems that correspond to the proposed problem. Then, some figures have been plotted to elucidates the effect of different physical parameters appearing in the problem on both the temperature and the velocity profiles. The presence of the thermal radiation and the viscous dissipation in the fluid flow are shown to have quite a dramatic effect on the temperature profiles. In culmination, cooling process in nuclear reactors and geothermal engineering especially in the presence of thermal stratification phenomenon can be adopted as an application of this study. The theoretical and the observed results provide a fairly good qualitative agreement.

IntroductionThe control of Newcastle disease virus (NDV) infection depends solely on vaccination which in most cases is not sufficient to restrain the consequences of such a highly evolving viral disease. Finding out substances for preparing an efficient anti-ND drug would be of high value. n-Docosanol is a saturated fatty alcohol with an inhibitory effect against many enveloped viruses. In this study, we evaluated the therapeutic effect of n-docosanol on NDV infection and shedding in chickens.MethodsChickens infected with a highly virulent NDV were treated with low to high concentrations of n-docosanol (20, 40, and 60 mg/kg body weight) for 4-successive days, once they showed the disease symptoms. Survival and curative rates, virus load, histopathological scoring, and virus shedding were defined.ResultsSymptoms development was found to discontinue 24–72 hours post-treatment. Survival rate in the NDV-infected chickens raised 37.4–53.2% after the treatment. n-Docosanol treatment was also found to significantly reduce virus load in the digestive (26.2–33.9%), respiratory (38.3–63%), nervous (26.7–51.1%), and lymphatic (16.4–29.1%) tissues. Histopathological scoring of NDV lesions revealed prominent rescue effects on the histology of different tissues. Importantly, n-docosanol treatment significantly reduced virus shedding in oropharyngeal discharge and feces thereby allowing the restriction of NDV spread.ConclusionOur findings suggest n-docosanol as a promising remedy in the control strategy of Newcastle disease in the poultry industry.

BackgroundSocially vulnerable communities are at increased risk for adverse health outcomes during a pandemic. Although this association has been established for H1N1, Middle East respiratory syndrome (MERS), and COVID-19 outbreaks, understanding the factors influencing the outbreak pattern for different communities remains limited. ObjectiveOur 3 objectives are to determine how many distinct clusters of time series there are for COVID-19 deaths in 3108 contiguous counties in the United States, how the clusters are geographically distributed, and what factors influence the probability of cluster membership. MethodsWe proposed a 2-stage data analytic framework that can account for different levels of temporal aggregation for the pandemic outcomes and community-level predictors. Specifically, we used time-series clustering to identify clusters with similar outcome patterns for the 3108 contiguous US counties. Multinomial logistic regression was used to explain the relationship between community-level predictors and cluster assignment. We analyzed county-level confirmed COVID-19 deaths from Sunday, March 1, 2020, to Saturday, February 27, 2021. ResultsFour distinct patterns of deaths were observed across the contiguous US counties. The multinomial regression model correctly classified 1904 (61.25%) of the counties’ outbreak patterns/clusters. ConclusionsOur results provide evidence that county-level patterns of COVID-19 deaths are different and can be explained in part by social and political predictors.

While the importance of physical (social) distancing in reducing the spread of COVID-19 has been well-documented, implementing similar controls in public transit remains an open question. For instance, in the United States, guidance for maximum seating capacity in single-destination public transit settings, such as school buses, is only dependent on the physical distance between passengers. In our estimation, the available models/guidance are suboptimal/inefficient since they do not account for the possibility of passengers being from the same household. This paper discusses and addresses the aforementioned limitation through two types of physical distancing models. First, a mixed-integer programming model is used to assign passengers to seats based on the reported configuration of the vehicle and desired physical distancing requirement. In the second model, we present a heuristic that allows for household grouping. Through several illustrative scenarios, we show that seating assignments can be generated in near real-time, and the household grouping heuristic increases the capacity of the transit vehicles (e.g., airplanes, school buses, and trains) without increasing the risk of infection. A running application and its source code are available to the public to facilitate adoption and to encourage enhancements.

A comprehensive study encompassing a general development and a presentation of results for the influence of the chemical reaction on the laminar Cross fluid flow and heat mass transfer is made here. The motion of the fluid is assumed due to the stratified stretching sheet which embedded in a porous medium. Some of important characteristics of the fluid such as the variable thermal conductivity and its dependence on the temperature field are mentioned. Accordingly, some account of the possible effects of heat generation on heat mass transfer in fluid flows is given. Numerical treatments have been introduced for the resulting coupled ordinary differential equations. Then, the results of the variation in the velocity profile, the temperature profile and the concentration profile due to porous parameter, thermal conductivity parameter, heat generation parameter, thermal stratification parameter and chemical reaction parameter are presented graphically. At the proposed physical conditions for the problem, the Sherwood number, the Nusselt number or the temperature gradient and the local skin friction coefficient were measured. It is interesting to observe that, both the solutal and the thermal stratification phenomena plays a dominant role in the mechanism of heat and mass transfer. Also, regarding the warming factors within the thermal boundary layer, both Darcy parameter and heat generation parameter have been proposed which are of special interest in heat transfer problems. Finally, the results pointed out the efficiency of the proposed numerical method, where it gives a good representation describing the mechanism of the flow, heat and mass transfer.

Heat transfer is a critical function in many technical, industrial, home, and commercial structures. As a result, the purpose of this study is to investigate the effects of slip velocity and variable fluid characteristics on Casson bionanofluid flow across a stretching sheet that has been saturated by gyrotactic microorganisms. The suggested system will be converted to a computationally tractable form using the Galerkin method. The shifted Vieta-Lucas polynomials are then used as basis functions on the provided domain to solve the nonlinear system of ordinary differential equations that has been constructed (ODEs). The results are presented in the form of graphs and tables to assess the impact of the problem’s governing parameters. The estimated solutions produced by using the proposed techniques were physically acceptable and accurate. The current outcomes are confirmed by comparing them to the available literature. It appears that the temperature distribution is enhanced whereas the velocity distribution declines, caused by rising values of the magnetic parameter, slip parameter, and Casson parameter. Also, the local Nusselt number escalates with the strength of the viscosity parameter while the friction drag decays with the same parameter. In addition, the effectiveness and accuracy of the proposed method are satisfied by computing and the residual error function.

Steel is an essential part of our life as it is used in wide applications as food equipment and heavy construction. The polymeric coating prevents the deterioration of the properties of metals due to rust and corrosion. This study investigated a reinforced polymeric coating to steel for enhancing barrier and mechanical properties. A comparison between different configurations of double-layered polymeric coatings was attained. The results showed that a maximum enhancement of 16.7%, 18.9%, 32.6%, 8.5%, and 5.7% in tensile strength, tensile strain, toughness, flexural strength, and flexural strain, respectively were achieved with a coating of epoxy filled with 1wt% Al2O3 microparticles before 1wt% Al2O3 nanoparticles on both sides as compared with pure epoxy coating. Adding micro/nanoparticles to epoxy coating enhanced the barrier properties of the coated steel against salt solution and citric acid environment as compared to pure epoxy coated steel.

This article describes a two-dimensional steady laminar boundary layer flow and heat mass transfer caused by a non-Newtonian nanofluid due to a horizontally stretching sheet. The non-dimensional parameters take into consideration and regulate the effects of convective boundary condition, slip velocity, Brownian motion, thermophoresis and viscous dissipation. The thermal radiation, which affects the flow’s thermal conductivity and the nanofluid’s variable viscosity are also taken into consideration. We propose that a hot fluid could exist beneath the stretching sheet’s bottom surface, which could aid in warming the surface via convection. The physical boundary conditions are non-dimensionalized, as are the governing transport set of nonlinear partial differential equations. By using the shooting approach, numerical values for dimensionless velocity, temperature and nanoparticle concentration are achieved. Distributions of velocity, temperature and concentration are plotted against a number of newly important governing factors, and the outcomes are then provided in accordance with those graphs. Additionally, the local skin-friction coefficient, the local Sherwood number and the local Nusselt number are discussed in order to further clarify and thoroughly explain the current problem. In order to validate the numerical results, comparisons are made with previously published data in the literature. There is a really good accord. Additionally, the current work has implications in the nanofluid applications.

This experiment evaluated the impact of the dietary addition of 1,3-β-glucans (GLU) on broiler chickens’ growth, intestinal histology, blood biochemical parameters, and immunity. Two hundred three-day-old male broilers (Ross 308) (97.93 ± 0.19 g/chick) were randomly assigned into four treatments with five replicates, each containing ten birds, in a complete randomized design. The four treatments were formulated with 0, 50, 100, and 150 mg 1,3-β-glucans kg−1 in broiler chicken diets. During the study, no significant impacts (p > 0.05) were observed in weight gain and feed conversion ratio (FCR) between treatment groups. Based on the results of total body weight gain and FCR, the optimal level of 1,3-β-glucan is 120 mg Kg−1. The intestinal histomorphology was improved by GLU supplementation, as indicated by increased villi height and villi height to crypt depth ratio (p < 0.01). All levels of supplemental β-1,3 glucan decreased the serum total cholesterol (TC), triglyceride levels, and low-density lipoprotein cholesterol (LDL-C) (p < 0.05). The serum levels of growth hormones (GH), triiodothyronine (T3), and thyroxine (T4) were increased in GLU-supplemented groups (p < 0.05). The serum immune indices (lysozyme activity, interleukin 10 (IL10), complement 3 (C3), and total protein levels) were increased in the GLU-supplemented groups (p < 0.05). Dietary GLU up-regulated the immunoexpression of CD3 (T-cell marker) and CD20 (B-cell marker) in the spleen of birds (p < 0.01). It can be concluded that 1,3-β-glucan can be added to broiler chicken diets for improving the development and integrity of the intestine and enhancing the bird’s immune status. The optimal level for 1,3-β-glucan dietary supplementation was 120 mg Kg−1. Dietary 1,3-β-glucan has a hypolipidemic effect and improves the hormonal profile of birds without affecting their growth rate.

The reasons why the model of non-Newtonian nanofluids is more applicable than other models, particularly those that take the porous medium into account, are studied here. Thus, we looked at the heat and mass transfer features of a non-Newtonian Williamson nanofluid flow due to a stretched sheet under the impact of chemical reactions, slip velocity, viscous dissipation, and the magnetic field in this article. The main focus is on a situation in which the properties of Williamson nanofluid, such as viscosity and thermal conductivity, change with temperature. After utilizing the shooting technique, a numerical solution to the suggested problem is provided. As a result, several graphs have been drawn to highlight how various physical characteristics that arise in the problems affect velocity, temperature, and concentration profiles. It was discovered that the heat and mass transmission processes are affected by the viscous dissipation phenomena, the slip velocity assumption, and the magnetic field. Theoretical and numerical results show a high level of qualitative agreement.

This study investigated the therapeutic effect of linagliptin and/or vitamin D3 on testicular steroidogenesis and spermatogenesis in cisplatin-exposed rats including their impact on endoplasmic reticulum (ER) stress and NF-κB/iNOS crosstalk. Cisplatin (7 mg/kg, IP) was injected into adult male albino rats which then were orally treated with drug vehicle, linagliptin (3 mg/kg/day), vitamin D3 (10 μg/kg/day) or both drugs for four weeks. Age-matched rats were used as the control group. Serum samples and testes were collected for further analyses. Cisplatin induced testicular weight loss, deteriorated testicular architecture, loss of germ cells and declined serum and intra-testicular testosterone levels, compared to the control group. There was down-regulation of steroidogenic markers including StAR, CYP11A1, HSD3b and HSD17b in cisplatin-exposed rats, compared with controls. Cisplatin-exposed rats showed up-regulation of ER stress markers in testicular tissue along with increased expression of NF-κB and iNOS in spermatogenic and Leydig cells. These perturbations were almost reversed by vitamin D3 or linagliptin. The combined therapy exerted a more remarkable effect on testicular dysfunction than either monotherapy. These findings suggest a novel therapeutic application for linagliptin combined with vitamin D3 to restore testicular architecture, aberrant steroidogenesis and spermatogenesis after cisplatin exposure. These effects may be attributed to suppression of ER stress and NF-kB/iNOS.

Abstract Williamson boundary layer fluid flow and heat transfer due to a nonlinearly stretching sheet is undertaken in this research. An important aspect of this study is that the thermal radiation and viscous dissipation phenomena are also included in this model. Because there is still much need for more accurate results, the viscosity and the fluid conductivity are assumed to vary with temperature. Our main purpose is to achieve a similar solution in this physical model. Here, we come across a highly nonlinear differential constitutive equations which are solved numerically after utilizing the shooting method. In this respect, it is noteworthy that the main characteristic developed here is that the study is made for the governing parameters and their effects on both the drag velocity and the heat transfer rate. Further, a significant effect of both radiation parameter and viscosity parameter on heating process is observed.

A shooting method has been introduced for determining the numerical solution of the ordinary differential equations which describe the Newtonian magnetohydrodynamic laminar fluid flow due to an unsteady stretching sheet together with the presence of thermal radiation and variable heat flux. The variable viscosity and variable conductivity are taken into consideration. Absence of magnetic field in some studies restricts the development of the energy-efficient heat transfer mechanism as is desired in numerous applications. The present study encompasses parameters such as unsteadiness parameter, porous parameter, viscosity parameter, magnetic number, radiation parameter, and conductivity parameter. It has been consummated that the proposed model is superior to other existing models for the industrial fluid.

Objective The COVID-19 pandemic in the U.S. has exhibited a distinct multiwave pattern beginning in March 2020. Paradoxically, most counties do not exhibit this same multiwave pattern. We aim to answer three research questions: (1) How many distinct clusters of counties exhibit similar COVID-19 patterns in the time-series of daily confirmed cases? (2) What is the geographic distribution of the counties within each cluster? and (3) Are county-level demographic, socioeconomic and political variables associated with the COVID-19 case patterns? Materials and methods We analyzed data from counties in the U.S. from March 1, 2020 to January 2, 2021. Time series clustering identified clusters in the daily confirmed cases of COVID-19. An explanatory model was used to identify demographic, socioeconomic and political variables associated with the outbreak patterns. Results Three patterns were identified from the cluster solution including counties in which cases are still increasing, those that peaked in the late fall, and those with low case counts to date. Several county-level demographic, socioeconomic, and political variables showed significant associations with the identified clusters. Discussion The pattern of the outbreak is related both to the geographic location within the U.S. and several variables including population density and government response. Conclusion The reported pattern of cases in the U.S. is observed through aggregation of the daily confirmed COVID-19 cases, suggesting that local trends may be more informative. The pattern of the outbreak varies by county, and is associated with important demographic, socioeconomic, political and geographic factors.

Using magnetohydrodynamics (MHD), the thermal energy and mass transport boundary layer flow parameters of Reiner–Philippoff fluid (non-Newtonian) are numerically investigated. In terms of energy and mass transfer, non-linear radiation, Cattaneo–Christov double diffusions, convective conditions at the surface, and the species reaction pertaining to activation energy are all addressed. The stated governing system of partial differential equations (PDEs) is drained into a non-linear differential system using appropriate similarity variables. Numerical solutions are found for the flow equations that have been determined. Two-dimensional charts are employed to demonstrate the flow field, temperature and species distributions, and rate of heat and mass transfers for the concerned parameters for both Newtonian and Reiner–Philippoff fluid examples. The stream line phenomenon is also mentioned in this paper. A table has also been utilized to illustrate the comparison with published results, which shows that the current numerical data are in good accord. The findings point to a new role for heat and mass transfer. According to the findings, increasing values of solutal and thermal relaxation time parameters diminish the associated mass and thermal energy layers. The current study has significant ramifications for chemical engineering systems.

The heat and mass transfer in magnetized non-Newtonian Williamson nanofluid flow, saturated by gyrotactic microorganisms due to a stretched sheet, is debated here. The rough sheet is subjected to uniform heat flux, and its velocity is proportional to its distance from the slit. Nanofluid viscosity and thermal conductivity are temperature-dependent, but microbe diffusivity and Brownian motion are concentration-dependent. Through similarity transformation, the system of modeled equations is reduced to dimensionless differential equations. We employed the shooting approach in conjunction with the Runge–Kutta scheme to obtain a solution for the physical model. For various combinations of the controlling parameters, some numerical results are found. When the generated results are compared to the existing literature, the highest settlement is found. According to numerical results, the skin-friction coefficient rises as the magnetic field and thermal conductivity parameters rise, while the opposite tendency is observed for both the slip velocity and viscosity parameters.