Modern Physics Letters B最新文献

Colloidal crystals formed with attractive interactions are used for in-situ observations of homogeneous nucleation processes in density-matched dispersion. We found globular and plate-like polycrystalline clusters stably suspended in the dispersion. Both clusters rotated randomly and moved freely with suspending in the dispersion. They were probably formed through homogeneous nucleation processes.

The longevity of solid oxide fuel cells is influenced by internal residual stresses, which may induce deformation or fracturing of components. This study investigates the residual stress distribution at the nonplanar cathode–electrolyte interface by approximating the actual interface with trigonometric functions and developing a three-dimensional (3D) model. The model reveals that the stress patterns at nonplanar interfaces can elucidate the genesis of interfacial cracks. During fabrication, anode contraction results in compressive stress within the electrolyte and tensile stress within the anode, with thermal discrepancies between layers being the primary cause of residual stresses. The reduction process diminishes these stresses, thus enhancing the mechanical integrity of the cell. Mitigating interface nonplanarity is beneficial for minimizing residual stress. At each interface crest, the electrolyte exhibits a local minimum in compressive stress, and a local maximum in shear stress occurs between each crest and trough. Furthermore, decreasing the initial porosity and NiO volume fraction can slightly lessen interlayer thermal discrepancies, with little effect on residual stresses.

The excellent photoelectric properties and low fabrication cost of perovskite solar cells have attracted extensive research attention. Despite this, long-term stability issues associated with perovskite solar cells continue to pose a significant barrier to commercialization. A new generation of two-dimensional (2D) and quasi-2D perovskites and newly introduced members of the 2D material family, have attracted growing attention due to their excellent stability and physical properties in contrast to their three-dimensional (3D) counterparts. Herein, we have presented the feasibility of using 4,4${}^{\prime }$-dipyridyl as an additive material for quasi-2D perovskite solar cells. As a result of the addition of 4,4${}^{\prime }$-dipyridyl, the solar cell device achieves a power conversion efficiency of 17.92% and a fill factor of 76.5%. Additionally, this strategy can be expanded to quasi-2D perovskite solar cells with an open-circuit voltage of 1.05$$V.

This paper presents an improved Cham method as an efficient technique for obtaining analytical exact solutions to nonlinear partial differential equations. We apply this method to solve the nonlinear Schrödinger equation in conformable operator, a challenging equation frequently used in various scientific fields. The method enables us to derive different traveling wave solutions, such as kink, coindal waves, breather waves, periodic singular solutions, and periodic multi-wave solitons. We also provide graphical representations of some of the obtained solutions to help understand their dynamic characteristics. These results highlight the effectiveness and adaptability of the method and demonstrate its potential to solve other partial differential equations.

This paper reports the mass and energy transmission characteristics of an electrically conducting mixed convective nanofluid flow past a stretching Riga plate. An additional effect of viscous dissipation, Arrhenius activation energy and heat source is also studied. The energy and mass transmissions are evaluated by a zero-mass flux of nanoparticle and convective boundary conditions. Buongiorno’s relations are proposed for the Brownian motion and thermophoretic diffusion. The similarity substitutions are employed to derive the non-dimensional set of modeled equations. The obtained set of equations is numerically processed via parametric continuation method (PCM). Several flow factors affecting the velocity, energy, and mass distributions are graphically discussed. It has been perceived that the fluid velocity field declines with the influence of velocity power index (m), while improves with the upshot of modified Hartmann number (Q). The effect of Schmidt number and chemical reaction diminishes the concentration profile $\phi (\eta )$. Furthermore, the energy curve enhances with the effect of thermophoresis factor, Biot and Eckert number.

In this paper, the rise behaviors of Taylor bubbles are investigated in sudden/gradual tubes filled with viscoelastic media via grid adaptive direct numerical simulations (DNS). The exponential Phan–Thien–Tanner (PTT) constitutive model is used to describe the viscoelastic rheological characteristics, and the phase interface is captured via the volume of fluid (VOF) method. The effects of tube structure (diameter ratio and structural angle) and fluid elasticity (expressed by the Weissenberg number Wi) on bubble dynamics have been studied. Our results indicate that bubbles are prone to rupture in the expansion tubes, mainly due to the dual effects of the wall and the elastic relaxation. The fluid elasticity suppresses the jet effect in a sudden expansion tube. Meantime, as the structural angle or the diameter ratio increases, the wall effect is weakened on axial or radial scales, inhibiting the bubble rupture. A large structure angle attenuates the wall effect, while changes in the diameter ratio slow down the radial momentum transfer near the wall region, both of which favor bubble integrity. We also obtain an exponential relationship between the critical rupture time and the structure angle. The dynamical Taylor bubbles can be operated by the structure of the tube and surrounding fluid viscoelasticity, which is of great significance in chemical engineering applications involving complex non-Newtonian fluids.

This paper aims to generate a Liouville integrable Hamiltonian hierarchy by introducing a specific matrix eigenvalue problem with four components. The adopted approach is the zero curvature formulation. A bi-Hamiltonian formulation is furnished through applying the trace identity, which shows the Liouville integrability of the resulting hierarchy. Two examples of generalized combined nonlinear Schrödinger equations and modified Korteweg–de Vries equations are presented.

This study focuses on the analysis of peristaltic transport of a hybrid nanofluid comprising deionized water as a base fluid and the multi-walled carbon nanotubes (MWCNTs) and copper oxide (CuO) as nanoparticles within a sinusoidal wavy porous duct, taking into consideration the influence of heat generation or absorption. The inaugural literature piece addresses the utilization of hybrid nanofluid in the context of peristaltic flow within ducts. To simplify the analysis, we have converted the non-dimensional equations into a two-dimensional (2D) coordinate system using the assumptions of a very long wavelength $(\delta <1)$ and low Reynolds number (Re). The non-dimensional equations governing the behavior of the hybrid nanofluid are then solved numerically using the finite volume method. Numerical solutions for temperature and the 2D peristaltic flow are obtained with the assistance of the Mathematics software MATLAB. These solutions are subsequently represented graphically using MATLAB software. The graphical results highlight several key findings for important parameters. First, it is observed that the pressure rise, temperature profile, and pressure gradient in the hybrid nanofluid (CuMWCNTs/H₂O) flow increases as heat generation increases. Furthermore, an increase in the nanoparticle volume fraction of both nanoparticles leads to a decrease in the pressure rise and pressure gradient in the hybrid nanofluid flow. Additionally, the widening of the channel reduces the pressure gradient and pressure rise in the CuMWCNTs/H₂O hybrid nanofluid. The analysis also includes the visualization of streamlines for peristaltic transport. These streamlines reveal that an increase in amplitude results in larger bolus sizes, while heightened heat generation has the opposite effect, decreasing bolus sizes. The results of this investigation can be found in various cooling devices as flows in the ducts are very frequently utilized for the cooling process of engines. A further topic is common in applications related to microfluidics, heat exchangers, and biomedical devices where peristaltic pumping is employed. Our results are in 100% agreement with the existing literature in special cases.

Hybrid nanofluids were expressed by heat-transfer fluids into greater surface dispersion capabilities, stability and diffusion related for traditional nanofluids. The effort on the flow of volumetric entropy generation and convective heat transport of MHD hybrid nanofluid is considered. Hybrid nanofluid involves the field over the orderly stretchable surface for variable heat flux with the resistance of electric field. Effect on convective heating and nonlinear thermal radiation is again contained in the interpreted figure. Mathematical equations such as momentum, energy, conservation of mass and entropy were collected as conversion to governing partial differential equations by ordinary differential equations, utilizing similarity variables. An efficient finite element method (FEM) is used. Numerical calculations were accomplished for silver–magnesium oxide water (Ag-MgO/H₂O) hybrid nanofluid and conventional silver water (Ag-H₂O) nanofluid. The graphs were created by the temperature, velocity, and entropy profiles. to analyse the impact on governing parameters. These skin friction and heat transfer rates are analysed through regression analysis. The important allegation expressed by the hybrid Nanofluid has the best heat transfer rate, which is related to convectional nanofluid. Further, It raised the Brinkman number and Reynolds number and developed a total entropy of the structure.