Modern Physics Letters B

Cross-diffusion effects are essential in industry because they can improve process efficiency, optimize product development, improve environmental sustainability, and drive technological advancements. The effects of cross-diffusion, aligned magnetization, and radiation are considered and adequately reported on the micropolar fluid boundary layer. The momentum, energy, and species reaction models are utilized to quantitatively represent the flow equations containing the thermophysical parameters at an aligned angle. The described fluid models are transformed into ordinary systems of derivatives. The solution to the resulting equations is determined via Fehlberg Runge–Kutta. The impacts of related terms are presented on various plots. The investigation revealed that the aligned angle strengthens magnetic field parameters, which can also lower the flow. For injection cases, microrotation has a parabolic distribution. An inclined value of radiation term contributed to improving the temperature profile. Temperature and concentration profiles rise and decrease with the Soret number, affecting heat, and species transport rates. The porosity and the thermal buoyancy parameter exhibit conflicting behaviors for both the coefficient of plate drag and the couple stress.

In this paper, we study the effects of different doping concentrations of O, Se, and Te atoms on the electronic structure and optical properties of single layer WS₂ based on the density generalization theory of the first principles. The most stable structure. The system doped with Te atoms shows a shift from direct to indirect band gap, and the band gap of the system doped with Se atoms increases slightly. When investigating the optical properties, we also found that the absorption of light in each doped system mostly occurs in the ultraviolet region, and the absorption of light in the system doped with O atoms decreases, while the absorption of light in the system doped with Se and Te atoms changes with different frequencies. The reflectivity is higher than the intrinsic state.

Polarization filters based on surface plasmon resonance (SPR) have undergone rapid development in recent years. In this work, a dual D-type PCF polarization filter based on SPR is designed and analyzed. The filter improves the limiting loss of the core mode by gilding the semi-circular split ring and inlaying amethyst. The influence of the structural parameters of the filter on the filtering characteristics is analyzed by the finite element method. The results show that the core mode losses of the x and y polarized light are 32dB/cm and 910.56dB/cm at 1.55$\mu$m, respectively. For a fiber length of 1000$\mu$m, the crosstalk and bandwidth are 763.11dB and 700nm, respectively. In addition, the impact of manufacturing errors in the structural parameters on the filter performance is discussed. The filter has excellent filtering characteristics and large potential in optical communication and optical sensing.

Acoustic black hole (ABH), as a new wave manipulation technique, shows excellent applications in vibration and noise reduction of structures. Nowadays, most ABHs use materials with a fixed elastic modulus, limiting their low-frequency performance. Herein ABH plates with variable elastic modulus (VM-ABH) is designed, and its vibration and acoustic radiation characteristics are investigated by using numerical analysis. The results show that the vibration response of VM-ABH has a decrease of 5–13.2dB relative to that of the uniform texture ABH (UT-ABH) in the frequency range of 10–5000Hz, and the degree of energy aggregation is significantly improved. Moreover, the sound pressure level was reduced by 3.6 dB. Meanwhile, by linearly varying the elastic modulus in the center region of the VM-ABH, the effects of gradient index and terminal elastic modulus on the damping characteristics and dynamic response are revealed. The research results provide new objects for the study of vibration and noise reduction of ABH.

In this work, we study the generalized shallow water wave equation to obtain novel solitary wave solutions. The application of this nonlinear model can be found in tidal waves, weather simulations, tsunami prediction, river and irrigation flows. To obtain the new exact solutions of the considered model, we have applied a novel analytical technique namely $(\frac{G^{\prime }}{G^{\prime }+G+A})$-expansion method. Using the aforementioned method and computational software, we have obtained different kinds of periodic and singular solitary wave solutions of the generalized shallow water wave equation. The obtained solutions are exponential function and trigonometric function solutions. Using 2D and 3D plots of the wave solutions, the dynamic behaviors of the developed solutions are displayed. The retrieved solutions validated the effectiveness and robustness of the proposed technique.

In this paper, a series of S${}_{0.05}$Co₄Sb${}_{11.6}$Te${}_{0.4}$ samples were prepared by high pressure and high temperature (HPHT) method under different pressures. The synthesis time was shortened from several days to 0.5 h. Te doping and S filling simultaneously optimized the thermal and electrical transport properties of the CoSb₃ materials. We found a porous architecture containing rich grain boundaries, different grain sizes, nano- to micrometer-sized pores, and a large number of dislocations, which can scatter a wide spectrum of phonons. Seebeck coefficient $\alpha$, electrical resistivity $\rho$, and thermal conductivity $\kappa$ were measured between 295 K and 773 K. The minimum thermal conductivity of S${}_{0.05}$Co₄Sb${}_{11.6}$Te${}_{0.4}$ synthesized at 3.0 GPa was 1.23 Wm${}^{-1}$ K${}^{-1}$, and its maximum zT value reached 1.07 at 773 K, especially the lattice thermal conductivity was as low as 0.49 Wm${}^{-1}$ K${}^{-1}$.

This primary goal of this analysis is to investigate how several slips affect the flow, heat, and mass performance of Darcy–Forchheimer unstable behavior beyond a stretching sheet using a numerical analysis of the Soret effect. The novel constitutive model Cattaneo–Christov is illustrated to analyze the features of thermal relaxation time. The Cattaneo–Christov method is used to predict heat and mass transport. A surface that slanders and has varying thicknesses propels the flow. Through the use of local similarity transformations, the governing nonlinear partial differential equations reduce to the coupled ordinary differential equations and include the momentum, energy, and concentration equations. The altered ODEs are calculated numerically using the Runge–Kutta Fehlberg scheme and an efficient shooting procedure. The physical properties of the temperature, concentration, and fluid velocity profiles are shown visually and shed light on the change of several governing parameters. For example, in comparison to the classical Fourier’s heat model, our result suggests that the Cattaneo–Christov heat flux constitution has lower temperature and thermal boundary layer thickness. In the meantime, a high wall thickness parameter greatly upgrades the rate of heat transfer, and thermal relaxation has the opposite effect. Discussion is held regarding the effects of various miscellaneous variables on temperature, concentration, and velocity.

This paper examines the stability analysis and exact solitary wave solutions of the nonlinear partial differential equation known as the Heimburg model. The several types of solitary wave solutions, soliton solutions and Jacobi elliptic doubly periodic function solutions are explored by using the extended Sinh-Gordon equation expansion approach. These investigations exhibit the system’s astounding diversity of waveforms, highlighting its potential applications in nerves and biomembranes. By selecting some appropriate values for the parameters, 3D, 2D, and its corresponding contour graph are plotted to represent the physical relevance of some of the solutions. Additionally, the linearized stability of this system is analyzed. The suggested approach is the finest resource for the analytical investigation of any nonlinear issue that occurs in various scientific fields.

This paper delves into the exploration of directional recursion operators within the realm of regular space curves modeled by Heisenberg systems. The central objective is to introduce a myriad of recursive flows, encompassing ferromagnetic and antiferromagnetic solutions, alongside a family of general normalization operators in the normal and binormal directions. The study employs the extended compatible and inextensible flow model of curves to examine the evolution models, providing a comprehensive understanding of their dynamics. A significant aspect of the investigation involves elucidating the evolution model in terms of anholonomy shapes and their density. The directional recursive operator, a focus of this study, demonstrates distinct results compared to traditional approaches. The reliability and applicability of the obtained results extend to the examination of various linear and nonlinear continuous dynamical systems.

In this work, an attempt is made for improving the piezoelectric properties of a lead-free (Na${}_{0.5}$K${}_{0.485}$Li${}_{0.015})$(Nb${}_{0.98}$V${}_{0.02})$O₃ ceramic system by doping manganese in it. The Rietveld analysis of XRD micrographs of the ceramics indicates the samples crystallizing into 99.86% of orthorhombic phase and very small traces of tetragonal phase around room temperature. The Curie temperature ($T_c$) is hardly affected by the incorporation of Mn${}^{4+}$ into the system. At the manganese concentration of 0.02wt.%, the ceramic system attains the peak values in its density, dielectric constant at room temperature (${\epsilon }_{\text{RT}}$), planar electromechanical coefficient ($k_p)$, piezoelectric coefficient ($d_{33}$), and remnant polarization ($P_r$). The optimum piezoelectric properties of $k_p=43$% and $d_{33}=193$ pC/N are observed for this composition. The study reveals that the modification of (Na${}_{0.5}$K${}_{0.485}$Li${}_{0.015}$) (Nb${}_{0.98}$V${}_{0.02})$O₃ with an appropriate quantity of Mn${}^{4+}$ can produce the desired changes in the crystallographic properties and densification so as to eventually improve its piezoelectric properties.

Design optimization of multilayer piezoelectric transducers is intended for efficient and practical usage of wideband transducers for fault diagnosis, biomedical, and underwater applications through adjusting layer thicknesses and volume fraction of piezoelectric material in each layer. In this context, we propose a parallel differential evolution (PDE) algorithm to mitigate the complexities of multivariate optimization as well as the computation time to achieve an optimized wideband transducer for the particular application. For lead magnesium niobate-lead titanate (PMN PT)- and PZT5h-based piezoelectric materials, the fitness function is formulated based on uniformity of mechanical pressure at the first three harmonics to achieve wide bandwidth in the required functional frequency range. It is carried out using a one-dimensional model (ODM), while input layer thicknesses and volume fractions of active material are evaluated using PDE. The simulation is performed on a parallel computing platform utilizing three different host machines to reduce computational time. Results of the proposed methodology for PDE are statistically represented in the form of minimum, maximum, mean, and standard deviation of fitness value, while graphically represented in terms of speedup and time. It can be observed that the execution time for parallel DE decreases with the increasing number of cores.

We design and simulate a near-zero flat dispersion As₂S₃ photonic crystal fiber (PCF) with a circular shape to generate a broad and smooth supercontinuum (SC). A near-zero flattened dispersion in the all-normal dispersion PCF is maintained in the 4–6.2$\mu$m wavelength range. A 6$\mu$m hyperbolic pulse is injected into this fiber, producing a flat spectrum from 2.45 to 8.4$\mu$m at a peak power of 5kW. The generated SC in anomalous dispersion PCF can cover multi-octaves by a pump laser with a 6500nm wavelength, 10kW of peak power, and a 90fs duration in 10cm of the proposed fiber structure. These results are achieved by optimizing the fiber structure through the core size. In general, the proposed structures could be used for broadband smooth low-cost SC generation.