Radiation Parameters Research Articles

Overview of the contributions from all lanthanide elements to kilonova opacity in the temperature range from 25 000 to 40 000 K

Context. It is now well established that the neutron star (NS) merger is at the origin of the production of trans-iron heavy elements in the universe. These elements are therefore present in large quantities in the ejected matter, whose electromagnetic radiation, called kilonova, is characterized by a significant opacity due to the high density of spectral lines belonging to many heavy ions. Among these, the lanthanide ions play an essential role since, with their open 4f subshell, they have a considerable number of transitions that can absorb emitted light. The knowledge of the atomic structure and the radiative parameters of these ions as well as the determination of the corresponding opacities is therefore of paramount importance for the spectral analysis of kilonovae. Aims. The main goal of the present work is to determine the relative contributions of the different lanthanide elements to the opacity of the emission spectrum of a kilonova in its early phase, that is, a few hours after the NS merger, where the conditions are such that the temperature is between 25 000 and 40 000 K. At these temperatures, the lanthanide ions whose charge states are between V and VII are predominant. Methods. We used the pseudo-relativistic Hartree–Fock (HFR) method extensively to calculate the relevant atomic data (energy levels, wavelengths, and oscillator strengths) in La-Lu V-VII ions. The corresponding monochromatic opacities were estimated from the expansion formalism. Results. We calculated the spectroscopic parameters for a total of more than 800 million radiative transitions in all the ions considered. These data were used to estimate the expansion opacities and Planck mean opacities for all the lanthanide elements at early-phase kilonova conditions between 25 000 and 40 000 K, making it possible to deduce the respective contributions of each element as a function of temperature. Atomic calculations were also carried out with the fully relativistic Multiconfiguration Dirac-Hartree-Fock (MCDHF) method in the specific case of the Yb V ion, as the available experimental data had not yet been compared with the theoretical calculations in our previous studies on lanthanide ions.

Mathematical modeling of entropy generation in MHD mixed convective Cu–Ag-Al2O3/H2O tri-hybrid nanofluid over an exponential permeable shrinking surface with radiation and slip impacts: Multiple solutions with stability analysis

The present investigation aims to determine the existence of a dual solution in magnetohydrodynamic (MHD) mixed convective radiative flow of Cu-Ag- A l 2 O 3 / H 2 O tri-hybrid nanofluid in a permeable Darcy–Forchheimer porous medium over an exponentially shrinking surface by considering velocity, thermal slips, and suction effects at the surface. This study focuses on assessing entropy production in novel coolant applications. To streamline the analysis, the complex nonlinear partial differential equations (PDEs) are simplified by converting them into a set of ordinary differential equations (ODEs) through the utilization of the similarity transformation technique. These ODEs are then solved utilizing the bvp4c numerical MATLAB function. Graphical and tabular analyses are conducted to investigate the impact of emerging variables on entropy generation, as well as velocity, temperature, skin friction coefficient, and Nusselt number. Due to the contraction of the surface, dual solutions are found, but dual solutions cannot be found beyond the critical values. The critical values of S C are 1.58928, 1.48700, and 1.66058, but ξ C are − 1.239499 , − 1.416999 , and − 1.130030 for Cu / H 2 O nanofluid, Cu − Ag / H 2 O hybrid nanofluid, and Cu − Ag − A l 2 O 3 / H 2 O tri-hybrid nanofluid, respectively. A positive minimum eigenvalue γ 1 signifies the existence of the upper stable solution branch, while a negative minimal eigenvalue indicates the presence of the lower unstable solution branch. The tri-hybrid nanofluid exhibits superior thermal properties compared to nanofluid and hybrid fluids. Adding nanoparticles to traditional fluids is perceived as improving their ability to transmit heat. The analysis has demonstrated that the thermal radiation and temperature slip parameters significantly influence the heat transfer rate. Thermal radiation is found to speed up the creation of entropy. Additionally, in the case of a stable solution, an increase in the Forchheimer number results in a deceleration of the liquid flow, an effect which is further amplified by the presence of the magnetic field and velocity slip parameter.

Thermal analysis of the water-based micropolar hybrid nanofluid flow comprising diamond and copper nanomaterials past an extending surface

This research demonstrates that hybrid nanofluids are superior to traditional fluids in terms of their capacity to transmit heat. An intensive investigation of hybrid nanofluids is needed to fill gaps in knowledge of heat transmission improvement methods. Therefore, scientists and researchers are combining different solid particles in various base fluids to boost the material's thermal conductivity. That's why the author has combined diamond and copper nanoparticles in a water solvent to examine the two-dimensional, steady, and incompressible magnetohydrodynamic (MHD) hybrid micropolar nanofluid flow over a permeable extending surface through the porous media. The Cattaneo-Christov heat and mass flux model is used to assess the heat and mass diffusion occurrences in temperature and concentration distributions. The similarity transformations are used to convert the PDEs along with their related boundary constraints into a set of nonlinear ODEs. A semi-analytical method known as HAM is used with the help of MATHEMATICA software to perform an analytical analysis on the set of nonlinear ODEs. The impacts of many important factors on the velocity, microrotation, thermal, and concentration functions are demonstrated through graphs and discussed in detail. The study results demonstrate that velocity distribution is a declining function of the magnetic field and porosity parameter. The magnetic field, Brownian motion, heat source, thermophoresis, and radiation parameters have positively influenced the thermal profile, while the thermal relaxation parameter has a negative influence on it. Nanoparticle volume fraction improves the Nusselt and Sherwood numbers. Heat transfer and skin friction are both amplified by the magnetic field. The skin-friction coefficient improves with an increase in the permeability parameter and the volume percentage of nanoparticles. Also, nanoparticles volume fraction enhances the mass transfer rate. Hybrid nanofluids have superior thermal characteristics over regular fluids.

Mechanical marvels: robots in carotid artery stenting - a systematic review of effectiveness in neuroendovascular interventions

Aim: Carotid artery disease, or carotid stenosis, is a critical medical condition carrying the risk of stroke and fatality. The underlying pathology involves the accumulation of atheromatous plaques, leading to luminal constriction and disrupted blood flow. Endovascular interventions, such as carotid artery stenting (CAS), aim to restore vessel patency. Robotic assistance in CAS surgeries is rapidly evolving globally, offering precision and fatigue-free capabilities. Despite growing interest, a dedicated systematic review on robotic applications in CAS is notably absent. Methods: Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search strategy involving five databases. Data extraction encompassed study origin, patient demographics, procedural details, procedure times, complications, fluoroscopy, and radiation parameters. Results: Over 199 articles were identified from five databases. Seven studies meeting inclusion criteria were analyzed. The predominant robotic system, CorPath GRX, demonstrated advantages such as remote operation, precision, and compatibility with various catheter sizes. Magellan Robotic System, employed in one study, showcased remote-controlled capabilities. These studies involved a total of 44 patients undergoing carotid artery stenosis procedures with robotic assistance. Reported complications included access site conversion, Angio-Seal device failure, and residual stenosis. Mean operation time varied from 34 to 85 min. Conclusions: The integration of robotic assistance in carotid interventions, as demonstrated by the CorPath GRX and Magellan Robotic System, holds significant promise in improving the precision and safety of CAS procedures. However, the limited number of studies, the high risk of bias, and the need for further research and standardization highlight the evolving nature of this technology.

MHD flow of blood-based hybrid nanofluid through a stenosed artery with thermal radiation effect

The MHD flow of a blood-based hybrid nanofluid with thermal radiation and stenosis effects is explored in this study. Gold (Au) and Copper (Cu) hybrid nanoparticles are assumed to be distributed in the blood. Relevant governing equations are established and appropriately normalized. The Caputo fractional-order derivative is used to convert the transient terms of normalized equations into time-fractional forms, which are then semi-analytically solved using the Laplace transform method to yield complex forms of modified Bessel functions. The concentrated matrix exponential (CME) approach is used to numerically determine approximate inverse Laplace transforms of the updated equations. The distribution patterns of velocity, temperature, and concentration are evaluated graphically. The results showed that the fractional-order derivative and the height of stenosis greatly influence the velocity, temperature and concentration profiles. We also observed that both velocity and temperature decreased with increasing values of Ha. Temperature rises with increasing values of the thermal radiation parameter (Ra) and the Eckert number (Ec) whilst concentration is enhanced with rising values of the chemical reaction parameter (Cr) and the Schmidt number (Sc). Our numerical results show that relevant parameters have considerable influences on skin friction, Nusselt number, and Sherwood number, which are important for understanding blood mobility, heat and mass transfer dynamics, and treating cardiovascular illnesses. Our results are also essential for controlling blood flow, temperature and delivery of drugs to diseased arteries in the human body.

Experimental Investigation for Enhancement of Heat Transfer Coefficient in Car Radiator by Using Multiwall Carbon Nanotube (MWCNT) Nanofluid

Improving heat transfer coefficient is a significant subject of study in many engineering domains. The use of nanofluids in car radiators might boost the heat transfer coefficient. The current study investigates a car's radiator's heat transfer coefficient and thermal conductivity. The heat transmission parameters of a car radiator were analyzed for coolant mass flow rates ranging from 600 to 1200 liters/hour and nanofluid concentrations ranging from 0.2 to 0.8% by volume. The primary coolant was prepared by combining water and ethylene glycol in a 60:40% combination with multi-walled carbon nanotube nanoparticles. The coolant's input temperatures were varied between 30 °C and 80 °C by impinging an air jet into the car radiator through a hallow cone nozzle plate with and without spacing. The result demonstrates that the volume flow rate of coolant on the tube side increases considerably as the heat transfer coefficient increases. At a nanoparticle concentration of 0.8 vol. %, the nanofluid's total heat transfer coefficient is enhanced by 12% compared with the base fluid. The heat transfer coefficient is improved by 42.6% for 0.8% volume of MWNCT nanofluid without spacing of the hallow cone nozzle plate and by 51.9% with spacing of the hallow cone nozzle plate.

Pulsating magnetohydrodynamic hybrid nanofluid flow with thermal radiation, viscous dissipation, and entropy generation: Application to bio-nanomedicine

The aim of this investigation is to explore the flow phenomena in two distinct hybrid nanofluids (with micropolar fluid as the base fluid) undergoing hydromagnetic pulsation between two vertical walls, accompanied by entropy generation. This study also explores the unique heat transfer characteristics of F e 3 O 4 − Ti O 2 and A l 2 O 3 − MgO hybrid nanofluids, with the effects of Ohmic heating, thermal radiation, and viscous dissipation. The goal of using hybrid nanofluids is to improve the performance of biological systems such as nano-drug delivery in arteries, magnetic bio-separation, artificial kidneys, pressure surges, magnetofection agents, biomedical engineering, cancer treatments, and brain tumor treatment. The governing partial differential equations are transformed into a system of ordinary differential equations, which are then solved numerically by a shooting technique with a fourth-order Runge-Kutta method using a bvp4c MATLAB solver. Graphical explanations are provided for the flow variables such as the velocity, the microrotation, the temperature, the entropy generation, and the Bejan number. The heat transfer rate is an increasing function of the thermal radiation parameter; when the thermal radiation parameter increases from 1 to 3 the increases in the heat transfer rates in micropolar fluid (the base fluid), first hybrid nanofluid ( F e 3 O 4 − Ti O 2 ), and second hybrid nanofluid ( A l 2 O 3 − MgO ) are respectively 55%, 51%, and 43.86%. However, while the heat transfer rate (the Nusselt number) is a diminishing function of the Hartmann number. Further, the outcomes reveal that the hybrid nanofluids with emerging physical effects are helpful to treat cancer patients, recovering the damaged tissues and cells in arteries, and various medical-related procedures.

Effectiveness of photobiomodulation therapy in the treatment of patients with an ankle sprain: a systematic review and meta-analysis.

Photobiomodulation therapy (PBMT) is widely used in the treatment of patients with musculoskeletal and sports disorders with a lack of significance in patients with sprain ankle. This review investigated the effect of PBMT on pain, oedema, and function in patients with an ankle sprain. A systematic search of the databases (MEDLINE, PubMed, EBSCO, Web of Science, Wiley Online Library, Science Direct, Physiotherapy Evidence (PEDro), and the Cochrane Databases) was performed from inception to the end of 2023 to identify any clinical study investigating the effect of PBMT on ankle sprain. PBMT parameters and measured outcomes were extracted. The primary measured outcome was pain and function, and oedema were secondary measured outcomes. Methodological quality was assessed using the PEDro scale. The level of evidence was determined by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. A random effect meta-analysis with forest plot was used to calculate standardized mean difference (SMD) at a 95% confidence interval and the overall effect size (ES). Six studies (598 patients) were included in the review and five studies in the meta-analysis. There were two fair-quality and four good-quality studies, with a moderate level of evidence on pain, and a low level of evidence on oedema and function. The meta-analysis revealed a significant overall effect of PBMT on pain with high ES [SMD - 0.88 (-1.76, -0.00), p = 0.05], with a non-significant effect on oedema and function with a medium ES [SMD - 0.70 (-1.64, 0.24), p = 0.14] on oedema and low ES on function [SMD - 0.22 (-0.69, 0.24), p = 0.35]. Significant heterogeneity was observed in all measured outcomes with high heterogeneity (I2 > 75%) in pain and oedema and moderate heterogeneity in function. PBMT is quite effective for patients with an ankle sprain. PBMT showed high effect size with a moderate level of evidence on pain intensity. The lack of significant effects of PBMT on function and edema with low level of evidence limit the confidence to the current results and recommend further large high-quality studies with higher PBMT intensity and fluency for standardisation of the irradiation parameters and treatment protocol. PROSPERO registration number (CRD42021292930).

Effects of Variable Thermal Conductivity on MHD Fluid Flow on Rotating Vertical Cone in the Presence of Darcy Forchheimer, Soret and Dufour Effects through a Porous Medium

This research investigated the effects of Variable Thermal Conductivity on MHD fluid on a Rotating Vertical Cone in the Presence of Darcy Forchheimer, Soret and Dufour effects through a porous medium. The system of nonlinear differential equations were transformed into first order differential equations and solved using shooting technique in Matlab package Bvp4c.Furthermore, the effects of various parameters over the main physical quantities are shown graphically and also extensively discussed. The result shows that Thermal conductivity increases Tangential Velocity, Temperature and decreases Normal Velocity. Dufour increases Tangential Velocity and decreases Normal Velocity. Radiation parameter R enhances Tangential Velocity and Temperature.

New YAC time-fractional derivative approach for water-based hydromagnetic chemically reacting radiative flow of nanofluid with copper nanoparticles past an upright plate

The current article utilizes the novel application of the Yang-Abdel-Cattani (YAC) fractional derivative to analyze the Casson nanofluid flow. Water nanofluid suspended with copper nanoparticles is considered in the flow phenomenon. Primarily, the dimensionless governing equations are converted to a fractional model by using a new description of fractional derivative, i.e. YAC fractional derivative. These fractional equations are then transformed and solved using the Laplace method. Finally, the solutions of these transformed equations are obtained in terms of a series of Prabhakar functions. The comparative results for Newtonian and non-Newtonian fluids are obtained using the analytical solutions and presented in the form of graphs. The effect of the chemical reaction, Casson parameter, radiation parameter, orders of the time-fractional derivative, and magnetic strength on velocity, temperature, and concentration fields is investigated. The fluid behavior of both Newtonian and Casson fluids is analyzed and presented in the form of graphs. Fluid temperature is enhanced by 5.22% with the use of copper nanoparticles with a 4% volume fraction. With the advancement of chemical reaction, the velocity and concentration of the nanofluid are observed to be decreasing.

Evaluation of COSMO-CLM Model Parameter Sensitivity in the Study of Extreme Events across the Eastern Region of India

The present study aims to identify the parameters from the Consortium for Small-scale Modelling in CLimate Mode (COSMO-CLM) regional climate model that strongly controls the prediction of extreme events over West Bengal and the adjoining areas observed between 2013 to 2018. Metrics, namely Performance Score (PS) screen out the most persuasive parameter on model output. Additionally, the Performance Index (PI) measure the reliability of the model and Skill Score (SS) establishes the model performance against the reference simulation leading to the optimization of the model for a given variable. In this study, parameter screening for four output variables such as 2m-temperature, surface latent heat flux, precipitation and cloud cover of COSMO-CLM is accomplished. For heat wave simulations, 2m-temperature and surface latent heat flux are explored whereas cloud cover and precipitation are examined for extreme rainfall events. A total of 25 adjustable parameters representing the following parameterization schemes: turbulence, land surface process, microphysics, convection, radiation and soil. Out of the six parameterization schemes, the scaling factor of the laminar boundary layer for heat (rlam_heat) and the ratio of laminar scaling factors for heat over sea and land (rat_sea) from the land surface process is sensitive to SLH, TP. The exponent to get the effective surface area (e_surf) from the land surface has a large impact on 2m-temperature. A few parameters from microphysics (cloud ice threshold for auto conversion), convection (mean entrainment rate for shallow convection) and radiation (parameter for computing the amount of cloud cover in saturated conditions) play a significant role in producing TP, and TCC fields. It is evident from the results that the parameter sensitivities on model performance depend on the choice of the meteorological field. Furthermore, in almost all input model parameters, the model performance reveals the opposite character in different domains for a given meteorological field.

ASSESSMENT OF REANALYSIS DATA FOR SOLAR PV OUTPUT FORECASTING IN THE PHILIPPINES: CASE OF PANGASINAN, NEGROS OCCIDENTAL, AND DAVAO DEL NORTE

Abstract. The sustainable energy transition in the Philippines requires accurate forecasting of solar PV output to optimize energy efficiency and grid management. While existing studies have emphasized the positive correlation between solar irradiance and PV production, this study aims to explore whether forecasting improves with the inclusion of weather data. This research conducts a comparative analysis between relying solely on solar irradiance against integrating various weather parameters to enhance solar PV output forecasting. The study focuses on three distinct locations (Pangasinan, Negros Occidental, and Davao Del Norte) and employs two models per each site: Model 1 (M1), which relies only on solar irradiance as predictors, and Model 2 (M2), which incorporates solar irradiance and weather parameters. Using Fifth Generation ECMWF Reanalysis (ERA5) Data, Principal Component Analysis (PCA) is conducted on the significant weather parameters. Extreme Gradient Boosting (XGBoost) with 5-fold nested cross-validation is applied for solar PV output forecasting. Models are assessed using Mean Absolute Percentage Error (MAPE) and skill scores. Results showthat while solar irradiance alone suffices for predicting solar PV output in Negros Occidental, incorporating weather parameters improves forecasting accuracy in Davao Del Norte and Pangasinan. This paper recommends caution in generalizing the findings to different regions with varying weather patterns, as the forecasting performance of the models is influenced by data quality, specific location, and prevailing weather conditions.

Bödewadt flow of thermally radiative hybrid nanofluid under the implication of horizontal magnetic field

It is a known fact that the implication of uniform magnetic field in transversal direction to fluid flow concerns the stabilization of velocity field and deterioration of heat transfer rate. It is now recognized that the applied uniform horizontal magnetic field is useful for stabilizing/destabilizing the flow rate, which is principally rely upon the direction angle such as cooling/heating the disk surface. Considering this, the present study investigates an incompressible three-dimensional Bödewadt flow above a stretchable with an implication of horizontal magnetic field. The Bödewadt flow defines a uniform and stable angular movement of fluid at sufficient large distance from the stationary surface. Such flow is balanced by the Centrifugal forces and is featured through radial pressure gradient. The radiative heat transfer attributes are characterized by the hybrid nanofluid, which is composition of Copper ( Cu ) and Titanium Dioxide ( Ti O 2 ) with water ( H 2 O ) as base fluid. A well-known approach of similarity variables is adopted to first normalize the flow model and then the resultant system of coupled non-linear ordinary differential equations is solved by Runge-Kutta-Fehlberg (RKF) MATLAB built-in package. The graphical results on flow and thermal fields are sketched for different values of dimensionless quantities. It is observed that direction angle in terms of horizontally applied magnetic field has stabilizing impact along radial axis close to the 0 ° or 90 ° , whereas destabilizing influence of direction angle is noticed between 30 ° − 60 ° . The temperature field is enhanced by the enlarged parametric values of thermal Biot number and solid volume fractions. Local Nusselt-number is increased at the disk surface by the radiation parameter.

Theory and design consideration of a THz superradiant waveguide FEL

We present theoretical analysis and design considerations of a THz superradiant FEL. We derive analytical expressions for the spectral parameter of THz radiation, emitted superradiantly in a rectangular waveguide using a Longitudinal Section Magnetic mode expansion. The results compare well with numerical simulations using UCLA GPTFEL code. GPT simulations of the accelerator e-beam transport show that the chirp provided by a hybrid photocathode RF gun, can produce tight bunching at the undulator site below σ = 100fs. This enables intense superradiant emission up to 3THz, limited by the beam bunching factor. Phase-space analysis of the beam transport indicates that keeping the beam bunching parameter small enough for higher THz frequency operation is limited by the energy spread of the beam in the gun.

Pulsatile nanofluid flow with variable pressure gradient and heat transfer in wavy channel

This research contributes to the comprehension of nanofluid behaviour through a wavy channel, emphasizing the significance of considering diverse influences in the modelling process. The study explores the collective influence of pressure gradient variation, magnetic field, porosity, channel waviness, nanoparticle concentration, and heat transfer on nano-blood flow in a two-dimensional wavy channel. In contrast to prior research assuming a constant pulsatile pressure gradient during channel waviness, this innovative study introduces a variable pressure gradient, significantly influencing several associated parameters. The mathematical model characterizing nano-blood flow in a horizontally wavy channel is solved using the perturbation technique. Analytical solutions for fundamental variables such as stream function, velocity, wall shear stress, pressure gradient, and temperature are visually depicted across different physical parameters values. The findings obtained for differing parameter values in the given problem demonstrate a significant influence of the amplitude ratio parameter of channel waviness, Hartmann number of the magnetic field, permeability parameter of the porous medium, volume fraction of nanoparticles, radiation parameter, Prandtl number, and the suction/injection parameter on the flow dynamics. The simulations provide valuable insights into the decrease in velocity with increasing magnetic field and its increase with higher permeability. Additionally, the temperature is observed to escalate with a rising nanoparticle volume fraction and radiation parameter, while it declines with increasing Prandtl number.

Unveiling second harmonic generation from femtosecond-laser microstructured Nd:YAG crystal

In this work we apply second harmonic microscopy to the analysis of damage tracks inscribed by femtosecond laser irradiation in a Nd:YAG crystal. While second harmonic generation is not expected in the bulk of this centrosymmetric material, the 2D and 3D images obtained via second harmonic microscopy show that the induced micro-modification of the crystal structure leads to a localized generation of the nonlinear signal. The nature of this modification and its dependence on irradiation and detection parameters is discussed. These findings demonstrate the capability of second harmonic microscopy for the morphological analysis of written structures in Nd:YAG and open the door for the design and fabrication of new nonlinear structures to be integrated in novel photonic devices.

Chelyshkov wavelet-based numerical technique for the solution of Darcy–Forchheimer flow of Erying–Powell radiated dusty fluid over a stretching sheet with Cattaneo–Christov heat flux

This article presents the Chelyshkov wavelet-based numerical technique (CWBNT) for the solution of the system of non-linear differential equations arising in the study of Darcy–Forchheimer flow of Erying–Powell radiated dusty fluid over a stretching sheet with Cattaneo–Christov heat flux. Initially, the proposed technique is implemented on the test problem having exact solution. The obtained results are highly accurate in comparison with the solutions obtained by shooting technique based Runge–Kutta Fehlberg 4th–5th order method. The proposed technique is applied to the governing equations of the considered dusty fluid problem. The results obtained for some fixed values of parameters resemble the previously published results. The comparisons validate the method. The flow behavior of dusty fluid is analyzed and the effect of various factors on the velocity and thermal attribute of the dust and fluid phase are studied. It is inferred that the Erying–Powell fluid parameters ε and α have entirely different effects on temperature, velocity profiles, and skin-friction coefficient. The local inertia parameter decreases the velocity and thermal relaxation parameter decreases the temperature. Enhancement in temperature ratio and radiation parameters escalates the temperature and Nusselt number. The proposed technique is simple, reliable, efficient tool to solve the differential equations arising in dusty fluid flow problems.

Numerical analysis of heat and mass transfer for forced convection radially magnetized Williamson nanofluid over a curved stretching surface

Present communication investigates the magnetohydrodynamics (MHD) bioconvection Williamson nanofluid with mass and thermal characteristics caused by the swimming of gyrotactic microorganisms subjected to a radially magnetic field and thermal radiation through a curved stretching surface. To emphasize the significance of thermal engineering processes, this novel mathematical model is designed to simulate the transportation of energy through the boundary layer flow of non-Newtonian nanofluid, taking into account the influences of thermophoresis, the density of motile microbes, and Brownian motion. Based on these assumptions, the fundamental governing equations are initially modeled in terms of partial differential equations (P DEs) through boundary layer theory and then formulated into a system of ordinary differential equations (ODEs) by utilizing similarity transformations. The numerical solution for the given nonlinear system, along with their respective boundary conditions, is computed using the BVP4c package in MAT LAB. To comprehensively evaluate the influence of various emerging parameters, results are discussed through graphs and tables for nanofluid’s temperature, concentration profile, local Sherwood number, skin fraction, axial velocity, heat transfer, and distribution of motile microorganisms. The nanofluid’s velocity experiences a decrease with the simultaneous increase of both curvature and magnetic parameters. As a primary finding, the motile microorganism profile exhibits a substantial increase concerning the curvature parameter. Similarly, the nanofluid parameters, including thermophoresis and Brownian motion, along with the radiation parameter, enhance the temperature of the nanofluid.

FRACTAL FRACTIONAL MODEL OF RADIATIVE HEAT AND MASS TRANSFER CHARACTERISTICS OF TIME DEPENDENT FLOW WITH VARIABLE VISCOSITY, INDUCED MAGNETIC FIELD, DUFOUR AND SORET EFFECTS: AN ENTROPY GENERATION

: In this article, the Caputo Fabrizio fractal fractional order derivatives operator with an exponential kernel was employed to examine the radiative heat and mass transfer characteristics of time dependent flow with variable fluid viscosity, induced magnetic field, Soret and Dufour effects. The local mathematical model for the flow problem is formulated by take into account the impacts of thermal radiation, heat source, and viscous dissipation. The governing equations in-terms of fractal fractional model with an exponential kernel were solved numerically using finite difference method. The influence of flow variables such as induced magnetic field, concentration field, entropy rate, thermal field, and velocity field profiles against the pertinent parameters are discussed through graphs. Increase the values of magnetic Prandtl number results to rises of induced magnetic field. Higher Dufour number significantly grows the thermal field. The fractal fractional parameters enhance the velocity field, thermal field, Bejan number, entropy rate, concentration field and induced magnetic field profiles. The velocity field profiles recede with higher values of fluid variable viscosity parameter whereas the thermal field and induced magnetic field has an opposite effect. Larger Soret number amplifies the concentration field. Increase of Brinkman number, thermal radiation parameter, and magnetic Prandtl number intensifies the entropy generation rate. Increases of Brinkman number, magnetic Prandtl number, Soret number and Dufour number leads to a decrease of Bejan number whereas Bejan number rises with an increase of thermal radiation parameter and heat source

Revolutionizing energy flow: Unleashing the influence of MHD in the presence of free convective heat transfer with radiation

This study investigates the complex interplay between radiation and magneto-flow on a porous, perpendicular plate immersed in a viscoelastic Maxwell fluid. The significance lies in understanding how the Lorentz force shapes dynamics and energy transfer in such systems, which is crucial for various industrial applications. Utilizing a comprehensive model that accounts for heat generation and absorption, we transform partial differential equations into ordinary ones through flow similarity analysis, providing valuable insights into the system's behavior. Employing the bvp4c solver in MATLAB, we evaluate velocity and energy profiles in Maxwell fluid flow. Graphical representations allow for a thorough examination of the influence of thermophysical parameters. Our findings reveal an intensified velocity profile attributed to prolonged material relaxation times.Furthermore, temperature profiles progressively increase with higher radiation and porous parameters. These results hold significant implications for industrial applications, particularly in Maxwell fluids' heat transport studies. Insights from this research can inform the design and optimization of systems such as ovens, boilers, cross-flow heat exchangers, and solar panels, enhancing efficiency and performance. Overall, this study contributes novel insights that advance understanding beyond previous efforts in the literature, paving the way for further exploration in this field. The primary finding of this study indicates that as the Rayleigh number increases, the velocity profile experiences an increase, whereas the temperature profile shows a decrease.