Pramana最新文献

{"title":"Significance of homogeneous–heterogeneous reaction on MHD nanofluid flow over a curvilinear stretching surface","authors":"Ram Prakash Sharma,&nbsp;Abhishek Sharma,&nbsp;J K Madhukesh,&nbsp;B C Prasannakumara,&nbsp;K V Nagaraja,&nbsp;Raman Kumar","doi":"10.1007/s12043-024-02809-z","DOIUrl":"10.1007/s12043-024-02809-z","url":null,"abstract":"<div><p>The current study aims to investigate heat transfer processes in chemically reacting processes, specifically focussing on the flow of an electrically conducting nanofluid over a curved extended surface. The work tries to describe the complex interaction between heat and mass transport phenomena in many applications, such as the biological sciences, catalytic processes and conflagration by including both homogeneous and heterogeneous processes in the framework. Introducing a convective heating strategy is a new technology that may boost circulation phenomena, perhaps leading to improved heat transfer performance. Additionally, the comparison between the Xue and Tiwari–Das models provides helpful insights into their individual suitability and precision in representing the heat transfer mechanism inside the examined system. The boundary layer approximation is used to handle the mathematical equations. Using the proper similarity variables, the controlling partial differential equations (PDEs) are effectively refined into the dimensionless form and computed numerically utilising the Runge–Kutta Fehlberg 4th–5th-order technique. The suggested characteristics of the physical parameters are examined and their relevant behaviour is illustrated graphically. The outcomes declare that the rise in magnetic parameter will decline velocity while enhance thermal profiles. Homogeneous and heterogeneous reaction strengths will decline the mass distribution while heat source/sink, solid fraction and Biot numbers will improve the temperature profile. In all circumstances, the Xue model exhibits a higher rate of thermal dispersion and temperature profile than the Tiwari–Das model.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142692011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Boosting the structure, thermal, optical and dielectric properties of a thermoplastic polymer by some nanoperovskites","authors":"Amani Alruwaili,&nbsp;Adel M El Sayed","doi":"10.1007/s12043-024-02850-y","DOIUrl":"10.1007/s12043-024-02850-y","url":null,"abstract":"<div><p>Given their technological applications, nanoperovskites are an intriguing class of multifunctional materials. To exploit their unique features while avoiding some of their shortcomings, developing low-cost and flexible perovskite<span>(/)</span>polymer nanocomposites with enhanced physicochemical properties attracts various research groups. In this report, two different perovskites, lanthanum ferrite nanoparticles (LF NPs) and lead titanate (LT) NPs were obtained by a solid-state route and mixed with a polyvinyl acetate/polyvinyl chloride (PVAc<span>(/)</span>PVC) thermoplastic blend. LF and LT nanostructuration have been investigated by the transmission electron microscope (TEM) and X-ray diffraction (XRD). The NPs’ good dispersion, uniform distribution on the homogeneous film surface and their complexation with the blend chains were clarified by XRD and field emission (FE)-scan electron microscopy (SEM). The Fourier transform infrared (FT-IR) technique identified the influence of these nanoperovskites on the vibrations of the blend’s characteristic (chemical) groups. The thermogravimetric analysis (TGA) also examined the impact of LF and LT NPs on the films' thermal stability. LT NPs are more effective at manipulating the transmission spectra in the UV–vis and IR regions and shrinking the blend’s optical band gap than LF. The study of the dielectric properties showed that the LT/blend had a higher dielectric permittivity, better conductivity (2.72 ×10⁻⁶ S/cm) and higher energy density (0.48 J/cm³). The absorption index, dual-band gap nature, dielectric loss and dielectric relaxation in the nanoperovskite/polymer were reported. The findings of this study declare that these nanocomposites are the best candidates for photonic devices and supercapacitor fabrication.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of q-deformed Rosen–Morse potential on the behaviour of interacting BEC systems","authors":"Neslihan Üzar","doi":"10.1007/s12043-024-02844-w","DOIUrl":"10.1007/s12043-024-02844-w","url":null,"abstract":"<div><p>In this study, the effects of <i>q</i>-deformed Rosen–Morse potential, particle number and interaction types (two-body, three-body and higher-order (HO) interactions) on Bose–Einstein condensate (BEC) were investigated. The wave functions, which are the solutions of the Gross–Pitaevskii (GP) equation for different conditions, and energies with Shannon information entropies of the BEC systems were calculated, considering attractive interactions between particles. It is found that <i>q</i>-deformed potential values, particle number and interaction types have significant effects on the main dynamics of the systems, while it is found that the high number of particles in the system is more effective than the interactions between the particles, especially, HO interaction is the dominant factor rather than the <i>q</i> deformation value. Also, the change in the entire dynamics of the systems starts around <i>q</i> = 0.1 because the trap potential becomes anti-symmetric at this value.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The improved saturation model in the nuclei","authors":"G R Boroun,&nbsp;B Rezaei","doi":"10.1007/s12043-024-02854-8","DOIUrl":"10.1007/s12043-024-02854-8","url":null,"abstract":"<div><p>We consider the nuclear shadowing in deep inelastic scattering (DIS) corresponding to kinematic regions accessible by future experiments at electron–ion colliders. The gluon distribution at small <i>x</i> is obtained using an improved dipole model which depends on the impact parameter for the atomic nucleus and is compared with nCETQ15 parametrisation group. The nuclear shadowing at small <i>x</i> is defined within the colour dipole formalism with respect to the mass number <i>A</i>. Its behaviour is predicted for light nuclei in a wide range of the impact parameter <i>b</i> and the transverse dipole size <i>r</i>. The nuclear saturation can be observed at large-<i>r</i> (small <span>(mu ^2)</span>). The behaviour of the nuclear ratio <span>(sigma ^{A}_{textrm{dip}}/sigma _{0})</span> using our model is similar to the Golec–Biernat–W<span>(ddot{textrm{u}})</span>sthoff (GBW) model in a wide range of <i>r</i> for light and heavy nuclei at small <i>x</i>.\u0000</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soft drug epidemic in deterministic and stochastic case studies","authors":"Islam M Elbaz,&nbsp;M A Sohaly,&nbsp;H El-Metwally","doi":"10.1007/s12043-024-02845-9","DOIUrl":"10.1007/s12043-024-02845-9","url":null,"abstract":"<div><p>Through the application of mathematical epidemiology principles, the formulation of the soft drugs model is established, and the complete dynamics of this deterministic model are contingent upon the crucial parameter called the basic reproduction number, denoted as <span>(R_{0}^{d})</span>. The stochastic soft drug epidemic models are developed by considering the parametric and non-parametric stochastic perturbation techniques. Dynamics of the two different stochastic models are determined using the analog stochastic thresholds <span>(R_0^{s_{1}})</span>, <span>(R_0^{s_{2}})</span>, respectively. Introducing suitable Lyapunov functionals enables us to establish sufficient axioms for the extinction and permanence of soft drug users in both deterministic and stochastic models. Moreover, the sensitivity of the deterministic and stochastic thresholds to some important parameters involved in the models is illustrated. For the verification of our theoretical results, we develop some numerical simulations using the Euler–Maruyama scheme.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive analysis of anisotropic stellar objects with quadratic equation of state","authors":"Kiran Pant,&nbsp;Pratibha Fuloria","doi":"10.1007/s12043-024-02846-8","DOIUrl":"10.1007/s12043-024-02846-8","url":null,"abstract":"<div><p>The present investigation examines the behaviour of compact relativistic objects characterised by static and spherically symmetric space–time for neutral anisotropic matter distribution. More specifically, we consider an equation of state (EoS), in which density and radial pressure are connected with each other quadratically. By smoothly matching the interior space–time with the exterior at the stellar surface, the appropriate values of the constant parameters for physically realistic solutions are obtained to model various compact stars. We explore the physical behaviour of compact stellar models SMC X-4, Vela X-1, CEN X-3, PSR J1614-2230, LMC X-4 and EXO 1785-248. Further, we describe several features of the compact stellar systems that exhibit physically acceptable attributes with no singularity. All important stability criteria, such as the energy conditions, causality conditions, Buchdhal condition and the adiabatic index are fulfilled by our neutral anisotropic compact star models. An in-depth comprehension of the physical characteristics of the proposed solution has been achieved through meticulous analytical and graphical examinations. By utilising this solution, the masses and radii of six compact stellar candidates mentioned above are optimised with the observed values obtained experimentally. The derived solution might be useful to enhance the understanding of the strong-field regimes and self-gravitating entities.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of gold and silver nanoparticles on the thermally radiating MHD slip blood flow within the stenotic artery using stability analysis and entropy optimisation","authors":"Gopinath Mandal,&nbsp;Dulal Pal","doi":"10.1007/s12043-024-02840-0","DOIUrl":"10.1007/s12043-024-02840-0","url":null,"abstract":"<div><p>The main aim of this investigation is to study the heat transport and entropy generation of human blood as a hybrid nanofluid (HNF) containing gold (Au) and silver (Ag) nanoparticles inside a Darcy–Fochheimer porous stenotic artery in the presence of thermal radiation and magnetic field. The primary reason for adopting Au and Ag nanoparticles as nanomaterials for drug delivery is because they exhibit potential drug transport and imaging properties for treating stenosed artery. Furthermore, velocity slip and convective boundary conditions at the surface of the artery are considered in this study. A method of suitable similarity transformations has been utilised to convert the partial differential equations (PDEs) into dimensionless ordinary differential equations (ODEs) and using the bvp4c built-in solver in MATLAB mathematical software, numerical solutions have been obtained. The plots of the results show that the hybrid nanofluid (Au–Ag/blood) has greater thermal conductance than the normal nanofluid (Au/blood). The temperature and velocity of the blood gradually increase as the percentage of nanoparticles in the blood flow grows. The heat transference rate increases with increase in Biot number (<i>Bi</i>) and radiation (<i>Nr</i>) effect, which helps in removing the toxic plaque from the artery. Due to the contraction of the artery, dual solutions are found, but dual solutions cannot be found beyond the critical values of suction (<i>S</i>) and shrinking (<span>(lambda )</span>) parameters. The critical values <span>(S_C)</span> from computation are 1.5851, 1.5949 and critical values <span>(lambda _C)</span> are 0.652, 0.781 for Au/blood nanofluid (NF) and Au–Ag/blood hybrid nanofluid (HNF), respectively. Also, the stability of blood flow is achieved by finding the lowest eigenvalue. A positive minimum eigenvalue (<span>(beta _1)</span>) denotes the upper stable solution branch, whereas a negative minimal eigenvalue indicates the bottom unstable solution branch. The entropy of the blood as the HNF flow was found to increase with nanoparticle volume fraction (<span>(phi _1, phi _2)</span>), porous parameter (<i>P</i>) and magnetic parameter (<i>M</i>). These results will help greatly to avoid brain stroke or heart attack caused by the burst of an artery.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stefan blowing impact and chemical response of Rivlin–Reiner fluid through rotating convective disk","authors":"Kotha Gangadhar,&nbsp;T Sujana Sree,&nbsp;Abderrahim Wakif,&nbsp;K Subbarao","doi":"10.1007/s12043-024-02836-w","DOIUrl":"10.1007/s12043-024-02836-w","url":null,"abstract":"<div><p>The present investigation of the rotating disk system is highly significant due to its many applications, such as in fluid thermal reactors, regulating fluidic systems and fluid stirring. Subject to the upper functions of the rotating disk, the Stefan blowing into the three-dimensional Reiner–Rivlin (R–R) fluid flow by the rotating disk affect the vertical direction. Thermal radiation and Cattaneo–Christov (CC) energy diffusion effects are examined into considering energy transport. The chemical reaction is accommodated in the concentration equation. The convective boundary conditions are considered in the disk surfaces. The ensuing nonlinear systems are determined by applying the Bvp4c routine along with the shooting method. The obtained outcomes are shown graphically with physical justification. The results show that R–R parameters cause a downturn in the radial and tangential velocity profiles as well as the temperature field. The curves of the temperature profile enhance with higher values of radiation parameter. Although this radiation falls onto the fluid surface and increases the temperature of the liquid as hot particles collide with cold particles, the skin friction coefficients decrease with suction. However, the heat and mass transfer rates are enhanced. The current model has been validated by comparing the simplified version of the investigation to a previously published article and a close agreement has been found.\u0000</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the bubble motion inside a peristaltic tube","authors":"Abha Kumari,&nbsp;Rajat Tripathi,&nbsp;Amit Kumar","doi":"10.1007/s12043-024-02834-y","DOIUrl":"10.1007/s12043-024-02834-y","url":null,"abstract":"<div><p>The motion of a long, axisymmetric bubble (fluid 1) inside a vertical peristaltic conduit containing a self-rewetting fluid (fluid 2) is discussed in this article. The fluid inside the tube and the floating bubble are immiscible, incompressible and have different densities. The peristaltic channel has two open ends. It is assumed that the bubble can move freely inside the tube without being restricted or deformed by the border wall. The effect of the density difference between the two fluids, Marangoni convection caused by the thermal and solutal gradient and an imposed back flow on the position and shape of the bubble have all been discussed. Motion of the bubble within a peristaltic tube, influenced by the Marangoni convection due to thermal and solutal gradients, has find various applications in the electrification of the atmosphere by sea bubbles, efficient mixing in microfluidic devices, improved cooling in heat exchangers, design of hydrophobic surfaces, spray coating thography techniques, enhanced mass transfer in chemical reactors, advancing various industrial and biomedical applications with precise fluid control. A mathematical model of the problem has been developed using a two-dimensional cylindrical polar coordinate system. The governing equations are in the form of linear partial differential equation and have been solved analytically. The effect of the thermo-solutal Marangoni convection in the microgravity region and the imposed back flow, impact of gravity-driven convection in the absence of the Marangoni convection or back flow, on the motion of bubble are discussed by plotting the position of the bubble. The initial radius and thermo-solutal Marangoni convection determine the bubble’s form as it evolves. When the initial radius falls below a critical value, the bubble becomes broader and shorter; conversely, when the original radius exceeds the crucial value, the bubble becomes longer and thinner.\u0000</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Taylor wavelet analysis and numerical simulation for boundary value problems of higher order under multiple boundary conditions","authors":"Ashish Rayal,&nbsp;Prerna Negi,&nbsp;Shailendra Giri,&nbsp;Haci Mehmet Baskonus","doi":"10.1007/s12043-024-02825-z","DOIUrl":"10.1007/s12043-024-02825-z","url":null,"abstract":"<div><p>The predominant objective of this study is to simulate higher-order linear and nonlinear initial-boundary value problems using approximation and collocation approach with the bases of Taylor wavelet. Differentiation is utilised in the function approximation approach to acquire expression for higher-order derivatives as well as solution to an unknown function. The mentioned scheme of wavelet approximation for higher-order differential equations is an intriguing scheme that has the potential to produce accurate and efficient results. The flexibility of the wavelet to the local character of differential equations of higher order corresponds well with the complexity caused by various boundary conditions. This study investigates the effectiveness of wavelet-based approach in solving higher-order differential equations under appropriate initial conditions, boundary conditions and Robin boundary conditions. Furthermore, a thorough error analysis is required to assess the dependability of these solutions. Therefore, maximum and minimum absolute errors, <span>(L_{2})</span> errors, relative error and experimental convergence order at various wavelet bases are evaluated to investigate the performance and effectiveness of the mentioned scheme. We have also compared the approximated solutions with other existing solutions to demonstrate the reliability and accuracy of the mentioned scheme.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}