Results in Physics最新文献

{"title":"MHD flow and heat transfer of Carreau nanofluid with slip effects, and modified Fourier–Fick’s law heat–mass fluxes over a paraboloid surface in porous medium","authors":"Tadesse Lamesse,&nbsp;Wubshet Ibrahim","doi":"10.1016/j.rinp.2025.108201","DOIUrl":"10.1016/j.rinp.2025.108201","url":null,"abstract":"<div><div>This study thoroughly analyzes the steady, three-dimensional boundary layer flow, heat transfer, and mass transfer of MHD Carreau nanofluid over a paraboloid surface embedded in a porous medium. It considers the integrated effects of Coriolis force, velocity slip, thermal radiation, Hall and ion slip, viscous dissipation, non-uniform heat source/sink, and chemical reactions on the flow. Main features of the analysis are the formulation of the Navier stokes equations, energy and concentration equations using the Cattaneo–Christov heat and mass flux models, rather than the classical Fourier’s law and Fick’s law, which is used to account for time relaxation effects. The governing nonlinear, coupled partial differential equations are converted into an ordinary differential system using similarity variables and then solved numerically using the finite element method. Sensitivity analysis using the response surface methodology exhibits the conditions for optimized heat transfer. The noteworthy findings are presented through graphical analyses of fluid flow parameters. The study reveals that the magnetic field slows fluid flow, while velocity increases with Hall and ion slip effects, mixed convection, concentration buoyancy parameters, and the Darcy number. Moreover, temperature increases with Brownian diffusion, the Eckert number, and radiation but decreases with a higher Prandtl number and thermal relaxation time. Moreover, as the Hall and ion slip parameters increase, the velocity profile also intensifies. The analysis reveals that the Prandtl number (Pr) is the dominant parameter, consistently exhibiting the highest Partial rank correlation coefficient(PRCC) value of 0.8650, emphasizing its crucial role in influencing the system’s behavior. Reliability is ensured through grid convergence analysis, and the numerical results were rigorously validated through detailed comparisons with previous studies and benchmark solutions. These findings are particularly relevant for energy systems, materials processing, and other industrial processes involving nanofluids in porous media, where precise control of thermal and fluid flow properties is crucial. Additionally, extending the study to other non-Newtonian fluids will broaden the applicability to a wider range of industrial applications.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108201"},"PeriodicalIF":4.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study of the couple stress on micropolar fluid flow saturating a porous medium in the presence of dust particles with hall current","authors":"Devilal Kumawat ,&nbsp;Devendar Kumar ,&nbsp;Mukesh Kumar Mahala ,&nbsp;Umar Ishtiaq ,&nbsp;Lipi Jain ,&nbsp;Ioan-Lucain Popa","doi":"10.1016/j.rinp.2025.108195","DOIUrl":"10.1016/j.rinp.2025.108195","url":null,"abstract":"<div><div>In this paper, the effect of couple stress on the micropolar fluid layer heated from below in the presence of dust particles through the porous medium with hall current has been investigated. The dispersion relation is derived using the normal mode technique, and the influences of porosity, magnetic field, dust particles, couple stress parameter, and micropolar parameters are analyzed both analytically and numerically. The numerical solutions are obtained using MATLAB. The impact of dust particles is a very important result of this model. These results have been compared with previous work, and they are in good agreement.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108195"},"PeriodicalIF":4.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of particle solidification growth evolution during slush hydrogen freeze-thaw process based on Phase Field-Lattice Boltzmann method","authors":"Fushou Xie ,&nbsp;Wan Guo ,&nbsp;Yang Yu ,&nbsp;Di Yang ,&nbsp;Yanzhong Li","doi":"10.1016/j.rinp.2025.108204","DOIUrl":"10.1016/j.rinp.2025.108204","url":null,"abstract":"<div><div>The remarkable performance exhibited by slush hydrogen makes it a promising choice for cryogenic propellants. The freeze–thaw method is the most commonly used method producing slush hydrogen due to its simplicity and reliability. However, the mechanism of preparing slush hydrogen by freeze–thaw method is not clear. Therefore, in order to figure out mesoscopic evolution law of hydrogen particles, this paper develops a two-dimensional(2D) Phase Field-Lattice Boltzmann Method (PF-LBM) to investigate the evolutionary mechanization of solidification growth of slush hydrogen particles during freezing and thawing in a stagnant flow field. The model is validated using the Lipton–Glicksman–Kurz (LGK) theoretical model for tip velocity, showing strong agreement with the predictions. The dendrite grows symmetrically during the freezing process. As the initial subcooling degree increases, the driving force of dendrite growth also rises, the size of the dendrite crystal increases and the speed of dendrite tip growth accelerates. During the melting process, the size of the dendrite decreases with time. This mesoscopic numerical study reveals the aging mechanisms of hydrogen dendrite. The heat flux leads to an increase in temperature, which affects the morphology of the solid–liquid interface. Additionally, the shape of the dendrite evolves from hexagonal to circular under the effect of heat diffusion, with the overall development tending towards the minimum of interfacial energy. This study explores the growth and aging mechanisms of slush hydrogen particles, which can provide theoretical guidance for the preparation of high-quality slush hydrogen.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108204"},"PeriodicalIF":4.4,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optoelectronic properties in CuO nanofibers, pure and doped with Mn","authors":"M. Piñón Espitia ,&nbsp;J.A. Duarte-Moller ,&nbsp;J.A. López-Gallardo ,&nbsp;M.T. Ochoa-Lara","doi":"10.1016/j.rinp.2025.108208","DOIUrl":"10.1016/j.rinp.2025.108208","url":null,"abstract":"<div><div>This research presents an optoelectronic study based on the dielectric function obtained from Kramers-Kronig analysis of CuO nanofibers (NFs), both pure (A) and 2.5 % Mn-doped (B), synthesized via the electrospinning method. The NFs were characterized using XRD and STEM, with a specific focus on analyzing valence electron energy loss (VEELS). This analysis was complemented by Cole-Cole diagrams to determine the band gap (E_g) and compare it with the EELS results. These properties reveal that the materials exhibit a semi-metallic nature due to the band gaps of 2.03 eV (A-NFs) and 2.85 eV (B-NFs), as well as negative conductivity in the dielectric function, and holes in the conduction band.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108208"},"PeriodicalIF":4.4,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chaotic analysis and a damped oscillator solitary wave structures to the generalized reaction Duffing model","authors":"Ghulam Hussain Tipu ,&nbsp;Waqas Ali Faridi ,&nbsp;Muhammad Bilal Riaz ,&nbsp;Fengping Yao ,&nbsp;Usman Younas ,&nbsp;Mubariz Garayev","doi":"10.1016/j.rinp.2025.108203","DOIUrl":"10.1016/j.rinp.2025.108203","url":null,"abstract":"<div><div>The aim of this research is to obtain soliton solutions for the generalized reaction Duffing model, a framework that generalizes many important models that illustrate key phenomena in science and engineering. In contrast to regular harmonic motion, this equation describes the motion of a damped oscillator with a more complex potential. We used the Kumar–Malik method in this work to obtain analytical solutions for the generalized reaction Duffing model, which is the first time this method has been used to extract soliton solutions in this particular setting. The equation is first reformulated as a nonlinear ordinary differential equation using traveling wave transformation. The approach proves particularly effective in handling nonlinear partial differential equations, yielding hyperbolic, Jacobi elliptic, trigonometric, and exponential function solutions under appropriate parameter constraints. A variety of innovative solutions emerge, including periodic wave solutions, dark compacton waves, kink waves, singular kink waves, bright solitons, breather waves, and singular-shaped solitons via the Kumar–Malik method. The solutions are then shown visually to demonstrate the wave behavior under various conditions. Our findings enhance the comprehension of the Duffing equation’s behavior across different physical contexts. The research uses extensive 2D and 3D graphic plot solutions of the proposed solutions for a better graphical understanding of the physical perimeters of solutions and proves the feasibility of the proposed method in solving complex nonlinear equations. The Chaotic analysis has also been discussed by perturbation term and initial conditions. It is important to note that the proposed methods are competent, credible, and interesting analytical tools for solving nonlinear partial differential equations. In addition, these solutions represent a valuable resource for the understanding of the complex behavior of physical systems, as well as for inspiring future research.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108203"},"PeriodicalIF":4.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a computational model for variable-order fractional Brownian motion and solving associated stochastic integral equations using barycentric rational interpolants","authors":"Shiva Naserifar,&nbsp;Farshid Mirzaee,&nbsp;Erfan Solhi","doi":"10.1016/j.rinp.2025.108199","DOIUrl":"10.1016/j.rinp.2025.108199","url":null,"abstract":"<div><div>This study introduces a novel numerical method for approximating variable-order fractional Brownian motion, representing a significant advancement in the field of stochastic processes. The proposed method enhances the modeling accuracy of complex phenomena by accommodating variable-order Brownian motion. Additionally, it mitigates the computational challenges typically associated with modeling such processes. The innovative approach employs a newly developed and straightforward matrix-based algorithm grounded in B-spline functions, offering an efficient, accurate, and computationally simple technique for approximating variable-order fractional Brownian motion. Also, this study focuses on solving a novel class of integral equations driven by variable-order fractional Brownian motion. The proposed method uses the features of barycentric rational interpolants and the spectral method to provide a simple and accurate approach, thereby reducing the complexities associated with solving such integral equations. The convergence of the method is analyzed in detail, and its theoretical robustness is emphasized. Furthermore, several numerical experiments have been conducted, demonstrating the reliability and adaptability of the method in challenging stochastic models. All numerical results have been analyzed using statistical methods to ensure greater reliability and accuracy.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108199"},"PeriodicalIF":4.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating epidemic model of infectious disease for stability analysis and approximation solution","authors":"Israr Ahmad ,&nbsp;Zeeshan Ali ,&nbsp;Mohammadi Begum Jeelani ,&nbsp;Ghaliah alhamzi ,&nbsp;Tariq Aziz","doi":"10.1016/j.rinp.2025.108202","DOIUrl":"10.1016/j.rinp.2025.108202","url":null,"abstract":"<div><div>In the current work, we formulate a fractional order model via the use of fractional Mittag-Leffler derivative (FMD) to describe the dynamics of Chikungunya virus. We investigate existence, uniqueness, positivity and boundedness of the concerned model. We identify threshold conditions for the endogenous persistence vs eradication of the virus, and predict the potential for outbreaks by computing reproduction numbers <span><math><mrow><mo>(</mo><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>)</mo></mrow></math></span>. Besides this, we also study the stability by determining the condition on which disease-free equilibrium stays stable. A comparative study and sensitivity analysis are also given in detail in the work. We conduct numerical simulations using a two-step Lagrange polynomial method that can efficiently investigate the dynamics of the specified model. Our findings highlight the role of fractional calculus (FC) in epidemiological models, which incorporate memory effects and genetic trait, and can lead to more accurate forecasts as well as efficacious public health policy. These findings not only support the theoretical foundation of infectious disease modeling, but also serve as a launching point for future research on other vector-borne diseases. We offer predictions of the model for different fractional orders, demonstrating how alterations in these orders affect the model predictions.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108202"},"PeriodicalIF":4.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cooling mechanical resonator to ground state in P T-symmetric cavity optomechanical system via pump modulation","authors":"Rui Chang,&nbsp;Suying Zhang","doi":"10.1016/j.rinp.2025.108184","DOIUrl":"10.1016/j.rinp.2025.108184","url":null,"abstract":"<div><div>We propose a scheme to cool a mechanical resonator to its ground state in a <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetric cavity optomechanical system. The system features a loss optomechanical cavity coupled to a gain cavity, with the loss cavity being driven by an amplitude-modulated laser field. Utilizing numerical simulation methods, we study the stability of the system and the cooling properties of the mechanical resonator in detail. We find that the system is almost stable within the unbroken <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetry region. The mechanical resonator achieves ground state cooling in both resolved-sideband and unresolved-sideband regimes. Notably, the cooling efficiency is significantly higher in the unbroken <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetry region compared to its broken counterpart. <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetry plays a pivotal role in optimizing the cooling performance of the mechanical resonator. These findings open new avenues for quantum manipulation using <span><math><mrow><mi>P</mi><mi>T</mi></mrow></math></span>-symmetric systems, with potential applications in macroscopic optical devices.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108184"},"PeriodicalIF":4.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced multiwavelength random fiber laser based on hybrid optical amplifier incorporating Sagnac loop mirror interferometer","authors":"Hanun Enani Muhamad Aliza ,&nbsp;Abdul Hadi Sulaiman ,&nbsp;Aiman Ismail ,&nbsp;Fairuz Abdullah ,&nbsp;Nelidya Md Yusoff ,&nbsp;Siti Azlida Ibrahim ,&nbsp;Md Zaini Jamaludin","doi":"10.1016/j.rinp.2025.108212","DOIUrl":"10.1016/j.rinp.2025.108212","url":null,"abstract":"<div><div>This work presents an enhanced multiwavelength random fiber laser employing a hybrid optical amplifier in combination with high nonlinearity devices, achieved through the integration of a polarizer with highly nonlinear fiber (HNLF). A Sagnac loop mirror interferometer serves as the comb filtering device, while the hybrid optical amplifier comprises an erbium-doped fiber amplifier (EDFA) and a semiconductor optical amplifier (SOA) as gain media. The SOA’s role in the laser cavity is to mitigate mode competition caused by the homogeneous broadening of the EDFA. The multiwavelength performance is enhanced by introducing nonlinear polarization rotation effect through the interaction of the HNLF, SOA, and polarizer (Condition A). The optimal lasing spectrum features 52 lasing lines within a 3 dB uniformity range and a high extinction ratio (ER) of 20 dB. The multiwavelength bandwidth is 9.5 nm, which is broader compared to previous studies on MWRFLs utilizing a linear cavity configuration. Removing the polarizer (Condition B) reduces the number of lasing lines to 51 and the ER to 19 dB. Furthermore, excluding the HNLF (Condition C) from the linear cavity decreases the spectral flatness and lowers the number of lasing lines to 32. A decrease in EDFA power results in fewer lasing lines, and variations in the angle of polarization controller has changed the ER value. Laser stability was evaluated over 2 hours, showing a peak power fluctuation of approximately 4 dB.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108212"},"PeriodicalIF":4.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulation of helium atom higher harmonic emission and attosecond pulse angle in inhomogeneous fields","authors":"Nan Xu ,&nbsp;Shu-Shan Zhou ,&nbsp;Yuan Wang","doi":"10.1016/j.rinp.2025.108190","DOIUrl":"10.1016/j.rinp.2025.108190","url":null,"abstract":"<div><div>With the rapid advancements in modern science, the interaction between laser fields and matter has become a focal point of research in various disciplines. In this study, we investigate high-order harmonic generation (HHG) modulated by spatially inhomogeneous laser fields, using helium atoms as a model system. Two types of nanostructures – single gold-tip and double gold-tip configurations – are employed to generate spatially non-uniform laser fields that interact with the helium atoms. Our results reveal that the angular orientation of attosecond pulses is significantly influenced by the inhomogeneous parameters of the laser field. For a single gold-tip nanostructure, when the inhomogeneous parameter along the x-axis is fixed at 0.002 and the parameter along the y-axis is varied from 0.002 to 0.006, the angle between the attosecond pulse and the x-axis shifts from 129°to 139°. In the case of a double gold-tip nanostructure, with the same variation in the y-direction parameter and the x-direction parameter held constant at 0.002, the attosecond pulse angle decreases from 115°to 102°. Different from previous studies, this paper combines two nanostructures and focuses on how the angle of attosecond pulse is affected by heterogeneous parameters, revealing new properties of attosecond pulse dynamics. These findings demonstrate the critical role of spatial field inhomogeneity in tailoring attosecond pulse dynamics.</div></div>","PeriodicalId":21042,"journal":{"name":"Results in Physics","volume":"72 ","pages":"Article 108190"},"PeriodicalIF":4.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}