International Journal of Modern Physics B

This paper investigates novel solitary wave solutions of the unidirectional Dullin–Gottwald–Holm model and employs the modified Khater (MKhat) method for studying the dynamical characterization of the prorogation of waves in shallow water. There are various solution types obtained such as kink, periodic, cone, anti-kink, etc. The accuracy of these solutions is checked by implementing He’s variational iteration technique. The analytical and numerical solutions are numerically simulated through 3D, 2D and contour plots for a visual explanation of the shallow water waves’ propagation and the match between both kinds of solutions. Additionally, the interaction between solutions is explained by some stream plots to show the local direction of the vector field at each point and a roughly uniform density throughout the property, which indicates no background scalar field. The novelty of the study’s solutions is explained by comparing it with the previously published articles.

This study aims at investigating the properties of magnetopolarons (MPs) in III–V compound semiconductors: GaP, GaAs and GaSb crystals. The obtained results from numerical calculation revealed that absolute value of ground-state (GS) binding energy $E_b$ of the magnetopolaron is affected by magnetic field, type of crystal as well as the parabolic and asymmetric Gaussian potentials, which leads to a series of interesting phenomena. The study of results obtained provides a good theoretical guidance on optoelectronic devices and quantum information. We have theoretically investigated the origins of these strange phenomena, and our findings provide sound theoretical direction for photoelectric technology and quantum information.

In this study, the dynamic viscosity of hydrocarbons was studied. This study was carried out with phenomenological aspects. The objects that were selected for this study are as follows: Cyclopentane, methylcyclopentane, ethylcyclopentane, propylcyclopentane, cyclohexane, methylcyclohexane and ethylcyclohexane. The studies were carried out in the temperature range $T=253$–373 K. It has been established that with the increasing temperature, the value of the dynamic viscosity of hydrocarbons decreases. In these materials, the mechanism of change in dynamic viscosity at high temperatures has been studied.

This research elaborates Darcy–Forchheimer magnetized flow based on non-Newtonian liquid induced by elongating surface. Rheological expressions of Casson liquid are utilized for mathematical analysis. Thermal stratification along with velocity and thermal slip aspects is considered. Heat transfer describes radiation and heat source/sink. The complex mathematical expressions featuring partial differential systems are rendered to ordinary differential systems by implementing boundary-layer approach. Numerical results are achieved through bvp4c scheme. Description of nondimensional factors is exhibited via pictorial and tabular depictions. The velocity and thermal field diminish when subjected to larger velocity and thermal slip factors.

This study aims to model two-dimensional Darcy–Forchheimer Casson nanoliquid incompressible flow confined by stretchable surface. The novel non-Fourier-Fickian (Cattaneo–Christov) heat-mass flux models are introduced. Hydromagnetic mixed convected flow is modeled. Species concentration under chemical reaction consideration is explored. Problem is formulated by employing basic fluid dynamics laws. Theory of boundary-layer (introduced by Prandtl) is utilized to simplify the highly nonlinear problems which are then rendered to ordinary differential systems under apposite transformations. Analytical solutions based on homotopy procedure are constructed. The convergence analysis is presented via $\hslash$-curves and tabular outcomes. The dimensionless factors are addressed in detail.

The heat conversation medium temperately regulates the heat exploitation effectiveness of solar energy. Nanofluids, a kind of functioning fluids with extraordinary thermal conductivity and strong light concentration, have been scrutinized and functionalized to progress the exploitation of solar energy. In recent times the current progress examines the nanofluids with the consideration of thermal sources as it can raise the heat transportation amount. Here, the purpose is to explore the thermal properties of Joule heating and thermal conductivity in magnetite Maxwell nanofluid. The concept of heat sink/source and chemical reaction are also studied. The achieved ordinary differential equations have been solved via homotopic algorithm. The enactment of functioning variables is examined. For Eckert number and variable conductivity factors, the Maxwell temperature field has analogous tendencies. The fluid concentration inflates for thermophoretic factor; however, slows down for the Brownian motion factor. The Brownian and thermophoretic factors decay for Nusselt number. Additionally, the excellent results have been achieved accompanied with possible existing prose precisely.

In this paper, NaYGeO₄:$x$Bi${}^{3+}$ phosphors were successfully prepared by high-temperature solid-state reaction. XRD patterns and refinement results show that Bi${}^{3+}$ ions are successfully incorporated into the matrix material and replaced by Y${}^{3+}$. The emission spectrum shows that the optimal doping concentration of the sample is 0.25%, and it is theoretically studied that the concentration quenching is caused by the nearest neighbor ions. The fluorescence lifetime curve showed that with the increase of Bi${}^{3+}$ concentration, the fluorescence lifetime first increased and then decreased. The thermal stability of the sample was studied, and it was found that when the temperature increased to 523 K, the luminescence intensity of the phosphor was still 70% of the initial intensity, and the activation energy was calculated to be 0.306 eV. Finally, the CIE color coordinates of the sample with the best luminous intensity were calculated as (0.1595, 0.0342), and the color coordinates are located in the blue light region.

Zinc oxide (ZnO) nanopowder samples were prepared by using co-precipitation method, with varying parametric conditions. Rietveld refinement technique is used to study the structural properties of synthesized samples. XRD and UV spectroscopy techniques have been used to characterize the samples which resemble ZnO nanostructures. Observed lattice parameters are $a=b=3.2482$ Å and $c=5.2011$ Å for sample A, $a=b=3.2500$ Å and $c=5.2062$ Å for sample B, $a=b=3.2497$ Å and $c=5.2017$ Å for sample C, $a=b=3.2550$ Å and $c=5.2122$ Å for sample D. The varying unit cell volume and axial ratio for all samples are calculated as 47.52–47.82 Å and 1.6006–1.6019. VESTA software is used to calculate the bond angles and lengths of Rietveld refinement data. UV-Vis spectroscopy analyzed the absorption, transmission, refractive index and band gap of samples for their possible use in different industrial applications.

Controlling the virus spreading in complex networks is very important to the research fields ranging from social science to technology. However, recent researches only consider information transmission and virus spreading as independent and uncorrelated, which neglect their interactive process in real systems. To study the interactive process between information transmission and virus spreading, in this paper, we propose a new virus information interactive spreading model on multiplex network. The multiplex networks can be divided into information transmission layer and virus spreading layer. The interactive spreading model considers the inherent characteristics of information by introducing the information forgetting and information loss mechanisms. Specially, by utilizing the mean field theory, the information transmission and virus process are unified to deduce the critical threshold of virus breakout. It shows that the critical threshold is not only related to the spreading properties of virus, but also influenced by the information density of individuals. We also find that the critical threshold is independent of the information generation probability, and the loss of the information will lead to a decrease. Finally, to verify the theoretical derivations, we apply it on both artificial network and real social network. The experimental results show that the simulations perfectly coincide with theoretical results, which verified the effectiveness of our model.

In this paper, we discuss the propagation of optical pulses in the nonlinear optical fibers. The generalized higher-order nonlinear Schrödinger equation (NLSE) is under consideration as a governing model. The studied model is composed of group-velocity dispersion, self-phase modulation, third-order dispersion, self-steepening and stimulated Raman scattering. Researchers have been studying a wide range of natural phenomena in depth, and nonlinear science has gradually become a part of people’s consciousness. We have extracted the optical pulses in different forms like bright, dark, singular and combined solitons by assistance of recently developed integration tool, namely the new extended direct algebraic method (NEDAM). Moreover, the solutions for the hyperbolic, periodic and trigonometric functions are retrieved. Using proper parameters in numerical simulations and physical explanations, it is possible to demonstrate the importance of the findings. It is proposed that the offered method can be utilized to support nonlinear dynamical models applicable to a wide variety of physical situations. We hope that a wide spectrum of engineering model professionals will find this study to be beneficial.