Pramana最新文献

{"title":"Numerical analysis on theoretical model of magneto-Williamson nanofluid in relation to viscous dissipation, double-diffusion convection, thermal radiation and multiple slip boundaries","authors":"S Bilal,&nbsp;Safia Akram,&nbsp;Maria Athar,&nbsp;Khalid Saeed,&nbsp;Alia Razia,&nbsp;Arshad Riaz","doi":"10.1007/s12043-024-02798-z","DOIUrl":"10.1007/s12043-024-02798-z","url":null,"abstract":"<div><p>Aerospace research is increasingly focusing on propulsion system analysis. Heat transmission at high temperatures controlled by thermal radiation is used in spaceship propulsion systems. Hence, the current work investigates the magneto-Williamson nanofluid peristalsis flow in relation to thermal effect and slip-boundary circumstances with double-diffusion convection. In the flow's opposite direction, a steady, static magnetic field is applied. A mathematical model with appropriate boundary conditions is built by considering the momentum, continuity and energy equations. By considering the long wavelength and low Reynold estimation, the resulting equations are further made simpler. Then a numerical solution to the resulting reduced partial differential equations is obtained. Finally, there is a visual representation of the non-Newtonian propelling flow parameters, which include the Brinkman number, Prandtl number, Hartmann number, radiation parameter, particle volume fraction, electric field and slip parameters. It is highlighted that enhancing the coefficient of thermophoresis strengthens the temperature contour because increasing the number of particles merged enhances thermophoretic power. Furthermore, because of the substantial migration of nanoparticles from a heated region to a cooled one, the distribution of concentration becomes less cumbersome. It is also revealed that the fraction of nanoparticles rises because of rising thermal radiation and Brownian motion because nanofluids have a significant temperature distribution that may affect the system's distribution.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204339","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":"Advanced deep learning approach with physics-informed neural networks for analysing the thermal variation through a radial fin applicable in heat exchangers","authors":"K Chandan,&nbsp;R S Varun Kumar,&nbsp;Naman Sharma,&nbsp;K Karthik,&nbsp;K V Nagaraja,&nbsp;Taseer Muhammad,&nbsp;Jasgurpreet Singh Chohan","doi":"10.1007/s12043-024-02823-1","DOIUrl":"10.1007/s12043-024-02823-1","url":null,"abstract":"<div><p>The radiation impact on the thermal distribution of the radial fin with the temperature-dependent thermal conductivity is discussed in this paper. The basic governing heat equation of the radial fin is formulated with the assistance of the Fourier law of heat conduction. The dimensional heat equation of the radial fin is non-dimensionalised utilising appropriate dimensionless variables and this ordinary differential equation (ODE) is tackled by employing the physics-informed neural network (PINN) scheme. The thermal attributes of the radial fin are investigated for different parameters like convection–conduction parameter, radiation–conduction parameter and thermal conductivity parameter. The outcomes of the systematic assessments of these parameters are demonstrated with the support of graphs. The rise in the thermal conductivity variable promotes thermal variation in the fin. A decrease in radiative–conductive variable scales augments the temperature dispersal through the fin. Furthermore, PINN incorporates physics equations directly into its architecture, unlike standard numerical approaches, which frequently require extensive mathematical expertise for accuracy. This approach enables PINN to give precise findings even when working with minimal training data, saving substantial time and resources.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204340","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":"First-principle study of strontium intercalation in bilayer graphene","authors":"O Farkad,&nbsp;R Takassa,&nbsp;F Elfatouaki,&nbsp;S Hassine,&nbsp;A El mouncharih,&nbsp;O Choukri,&nbsp;A Ouahdani,&nbsp;E A Ibnouelghazi,&nbsp;D Abouelaoualim","doi":"10.1007/s12043-024-02759-6","DOIUrl":"10.1007/s12043-024-02759-6","url":null,"abstract":"<div><p>Modifying electrical and optical properties in two-carbon materials is essential for electronic devices, energy storage and biosensor applications. We report a comparative study of the effect of systematically intercalated strontium atoms in AA- and AB-stacked bilayer graphene (BG) in the framework of density functional theory (DFT). The electronic band structures, the total and partial electronic density of states and the dielectric function are studied. We show that the intercalation of atoms can influence both electronic properties. Our results show that the Dirac cones, a signature of graphene, are translated into the conduction band. This property may be useful in band-gap tuning applications of nanodevices. The optical properties were calculated parallel and perpendicular to the graphene sheet under polarised electric fields. The calculated optical properties show that the intercalation of Sr in the AA- and AB-stacked BGs promotes IR absorption. The findings provide a basis for developing graphene intercalary compounds, which can be used in optoelectronics to control the absorption of light wavelengths and specifically in biosensor applications.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204395","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":"Visualising the structure of liquid germanium dioxide under compression","authors":"Nguyen Van Hong","doi":"10.1007/s12043-024-02813-3","DOIUrl":"10.1007/s12043-024-02813-3","url":null,"abstract":"<div><p>Oxygen packing factor (OPF) and atomic-level structure characteristics of the germania system at high temperature and pressure were investigated based on molecular dynamics (MD) simulation. Data analytic techniques, including Monte Carlo method, machine learning and data mining, were used to gain insights from the simulation data. We focus on elucidating the correlation between structure and OPF under high pressure. The research results have established the relationship of the network structure, polyamorphism, liquid–liquid phase transformations and microphase separation with OPF. The research findings revealed promising possibilities in developing novel materials and their applications.\u0000</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204394","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":"Effect of heat and mass transfer on the MHD (mathrm{Al_2O_3/H_2O}) and (mathrm{Al_2O_3/C_2H_6O_2}) nanoliquid through an asymmetric vertical channel","authors":"P Praveen Kumar,&nbsp;S Balakrishnan,&nbsp;A Magesh","doi":"10.1007/s12043-024-02814-2","DOIUrl":"10.1007/s12043-024-02814-2","url":null,"abstract":"<div><p>The impact of magnetic field on the peristaltic motion of alumina/water (<span>(mathrm Al_2O_3/H_2O))</span> and alumina/ethylene glycol (<span>(mathrm Al_2O_3/C_2H_6O_2))</span> nanofluids in a vertical asymmetrical channel with mass/heat transfer was examined in this study. Unsteady governing equations were derived for the present problem. The Galilean transformation was used to transform the unsteady governing equations into steady ones. Reducing partial differential equations yields ordinary differential equations with the implementation of the long wavelength and low Reynolds number approximations. Coupled nonlinear differential equations (concentration and temperature equations) were solved analytically using the perturbation technique. In a similar fashion, the exact solution to the stream function is computed. MATLAB software was used to plot temperature, pressure rise, velocity and concentration, while MATHEMATICA software was used for generating streamlines. The findings suggest that, in comparison to the <span>(mathrm Al_2O_3/H_2O)</span> nanoliquid, the velocity profile for the <span>(mathrm Al_2O_3/C_2H_6O_2)</span> nanoliquid shows significantly larger magnitudes.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204398","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":"Sliding dumbbell method to search for the CME in heavy-ion collisions","authors":"Madan M Aggarwal,&nbsp;Anjali Attri,&nbsp;Sonia Parmar,&nbsp;Anjali Sharma,&nbsp;Jagbir Singh","doi":"10.1007/s12043-024-02810-6","DOIUrl":"10.1007/s12043-024-02810-6","url":null,"abstract":"<div><p>This study explores the chiral magnetic effect (CME) in ultra-relativistic heavy-ion collisions. The CME, observed as back-to-back charge separation along the magnetic field axis, is investigated using the newly developed sliding dumbbell method (SDM) applied to Au<span>(+)</span>Au events at a centre-of-mass energy <span>(sqrt{s}_{text {NN}}=)</span> 200 GeV generated by the AMPT model with string melting configuration. The CME-like signal is externally injected in the events by flipping charges of pairs of particles perpendicular to the reaction plane. The study reports a significant enhancement of the CME-sensitive 3-particle <span>(gamma )</span> correlator in events with high back-to-back charge separation, in a given collision centrality. Additionally, a linear relationship is observed between the <span>(sqrt{|gamma |})</span> correlator for the same-sign charge pairs and positive charge asymmetry (<span>(langle A^{+}rangle )</span>) across the dumbbell in CME-enriched sub-samples. Furthermore, the fraction of CME in <span>(Delta gamma )</span> (difference between the opposite and same sign <span>(gamma )</span> correlators) is presented across different collision centralities having different percentages of externally injected CME-like signal. Overall, the research aims to understand and detect the CME through innovative experimental method and detailed analysis of the event structure.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204396","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 non-equilibrium thermodynamical study of warm inflation and swampland conjectures","authors":"Akash Bose,&nbsp;Subenoy Chakraborty","doi":"10.1007/s12043-024-02821-3","DOIUrl":"10.1007/s12043-024-02821-3","url":null,"abstract":"<div><p>The present work deals with warm inflationary scenario from the viewpoint of non-equilibrium thermodynamics. Due to the interacting two-fluid system, the dissipative mechanism in warm inflation can be considered as effective bulk viscous pressure in second-order non-equilibrium description of thermodynamics. It is found that the interaction term is proportional to the enthalpy density of the formed particles. The warm inflation has been analysed using slow-roll approximation and an expression for the interaction term has been obtained. The formulation of warm inflation in the non-equilibrium thermodynamical prescription has been presented as a lemma. Lemma 2 shows the inter-relation between slow-roll approximation and quasistable radiation bath using the Friedmann equations. Finally, warm inflation has been examined from the point of view of swampland conjectures.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204397","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":"Hydromagnetic micropolar fluid flow over a stretching sheet under viscous dissipation, thermal radiation and Dufour–Soret effects","authors":"Kushal Sharma,&nbsp;Laltesh Kumar,&nbsp;Atar Singh,&nbsp;Vimal K Joshi","doi":"10.1007/s12043-024-02777-4","DOIUrl":"10.1007/s12043-024-02777-4","url":null,"abstract":"<div><p>In the present investigation, we investigated the chemically reactive, laminar flow of a micropolar fluid over a stretching sheet in the presence of a transverse magnetic field, thermal radiation and the mutual effect of Soret–Dufour and viscous dissipation. The governing partial differential equations are converted into a system of nonlinear ordinary differential equations for finding the mathematical solutions and the transformed system is solved using the bvp4c algorithm in the MATLAB environment. Effects of different physical factors on dimensionless velocity, microrotation, temperature and concentration profiles are addressed and illustrated graphically. When the Schmidt number is low, it indicates that the momentum diffusivity dominates over the mass diffusivity.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204399","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":"Dynamical behaviours with various analytic solutions to a ((2+1)) extended Boiti–Leon–Manna–Pempinelli equation","authors":"Shalini Yadav,&nbsp;Aniruddha Kumar Sharma,&nbsp;Rajan Arora","doi":"10.1007/s12043-024-02784-5","DOIUrl":"10.1007/s12043-024-02784-5","url":null,"abstract":"<div><p>The study aims at different families of analytical solutions and their dynamics for the (<span>(2+1)</span>)-dimensional extended Boiti–Leon–Manna–Pempinelli (eBLMP) problem, which is widely used in the fields of physics such as non-linear optics, fluid dynamics, mathematical physics, plasma physics and quantum mechanics. The paper utilises two recently developed efficient mathematical methods: the generalised exponential rational function (GERF) method and the generalised Kudryashov (gK) method. These two methods are versatile, simply applicable to enlighten the new non-linear waveforms. Consequently, these discoveries enhance our understanding of complex systems like (<span>(2+1)</span>)-dimensional eBLMP in the realm of non-linear science.\u0000</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204400","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":"Multiple-relaxation-time lattice Boltzmann simulation of viscoplastic Bingham nanofluids in a suddenly expanded channel: a systematic numerical study","authors":"Muhammad Zawad Mahmud,&nbsp;Md Mahadul Islam,&nbsp;Md Mamun Molla,&nbsp;Md Farhad Hasan,&nbsp;Sadia Siddiqa","doi":"10.1007/s12043-024-02795-2","DOIUrl":"10.1007/s12043-024-02795-2","url":null,"abstract":"<div><p>The multiple-relaxation-time (MRT) lattice Boltzmann method (LBM) is used in a suddenly expanded channel to demonstrate the flow of viscoplastic Bingham nanofluid with Al<span>(_2)</span>O<span>(_3)</span> nanoparticles. The geometry has two sections namely, inlet and outlet, and the corresponding heights are denoted by <i>h</i> and <i>H</i>, respectively. The length of the entire channel is 20<i>H</i>, and the expanded channel has a height of 16<i>H</i>. The purpose of the MRT-LBM simulation is to investigate the impact of changing the Bingham number (<span>( 0 le Bn le 200)</span>), keeping the Reynolds number (<i>Re</i>) fixed for different volume fractions (<span>(phi =)</span> 0.00 and 0.04). In addition, the consequences of variations in the Reynolds number (<span>( 50 le Re le 1000 )</span>) at constant Bingham number (<i>Bn</i>) are also studied for those two different volume fractions. The results demonstrate that with fixed <span>(Bn=2)</span>, <span>(Re=400)</span> is the point where the flow pattern and recirculation regions are exactly the same for both volume fractions. An increase in <i>Re</i> causes the recirculation regions to grow for a fixed <i>Bn</i> for both volume fractions as <i>Re</i>’s rise increases the velocity and decreases the viscous force. <i>Bn</i>’s increment with <i>Re</i> and volume fraction unchanged lowers the recirculation region’s size due to a rise in viscous force. Higher <i>Re</i> and lower <i>Bn</i> cause the more significant recirculation regions to break down into smaller areas. Incrementing the volume fraction lowers size of the recirculation region. An unstable flow was observed for higher <i>Bn</i> (e.g., <span>(Bn ge 100)</span>) and lower <i>Bn</i> (e.g., <span>(0 le Bn le 10)</span>) when <span>(Re ge 500)</span> for both volume fractions in maximum cases. Unstable flow for lower <i>Bn</i> makes the recirculation regions asymmetric, and when <i>Re</i> is high, the recirculation regions break down for the base fluid (<span>(phi =0.00)</span>). When <span>(Re=300)</span> and <span>(Bn=2)</span>, the length of the recirculation region of the upper wall decreases by <span>(28.58%)</span>, and the length of the lower wall falls a bit less by <span>(26.37%)</span> when <span>(phi )</span> is increased from 0.00 to 0.04. For <span>(x/h=2)</span>, the nanoparticle mixed fluid’s velocity (<span>(phi =0.04)</span>) never gets a negative magnitude till the final position for <span>(Re=700)</span>. In most situations, an increased volume fraction increases the skin-friction effect on both walls.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946911","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}