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The oil-immersed transformer is a crucial piece of equipment in the power system. Operating at the specified temperature is necessary to ensure the normal operation of the transformer. The insulation paper on the winding surface has a significant impact on the actual temperature of the transformers, which is often overlooked by researchers. The one-dimensional steady-state heat conduction model of the transformer is established by analyzing the heat diffusion process of winding to transformer oil. Atomic force microscope was used to observe the microsurface structure of insulation paper and copper. According to the experiment, the heat transfer resistance in the series process of heat transfer at 7 0 ∘ C is 0.0138 m2 K/W. Space thermal circuit model of transformer is established by thermoelectricity analogy method, and the simulation circuit is optimized according to the boundary conditions set up in the actual environment. The results show that the error of the hot spot temperature is closer to the measured temperature and decreases by 2.5% when considering the thermal resistance of insulation paper. [ABSTRACT FROM AUTHOR]

This research paper investigates the behavior of optical fiber pulses by studying the solitary wave solutions of the perturbed Chen–Lee–Liu (CLL) equation. The perturbed CLL equation is derived from the perturbed Schrödinger equation. Two analytical approaches for obtaining the innovative soliton-wave solutions are presented in this paper, and their reliability is examined by using a well-established numerical method. The accuracy of pulse wave analysis in an optical cable is demonstrated through a series of graphical representations. Our study introduces scientific novelty, as evidenced by the comparative analysis of our data with those of previous research papers. This research contributes to enhancing the understanding of the kinetics and physical behavior of pulses in optical fibers, which holds implications for the advancement of optical communication technologies. [ABSTRACT FROM AUTHOR]

In this paper, the structural, electrical and optical effects of WS2 doped with silicon atoms after torsional deformation are investigated using first-principles calculations. First-principles calculations for metal disulfide-WS2. The doping of Si atoms gives WS2 a tunable band gap, and the surface state is successfully transformed from a 2.0 eV band gap to a quasi-metal with a 0.254 eV band gap, and the change of the doped Si atoms causes a redshift in the absorption peak and a blueshift in the reflection peak. The band gap of WS2 can be effectively adjusted by torsional deformation on the basis of Si-doped atoms in the range 0.254–0.052 eV. Calculations of optical properties show that Si-doped WS2 with a torsion angle of 1 0 ∘ has the lowest light absorption peak and Si-doped WS2 with a torsion angle of 8 ∘ has the lowest light reflection peak. This paper opens up new possibilities for designing materials on demand. [ABSTRACT FROM AUTHOR]

This paper presents an analytical solution for a complex mechanical system consisting of a pendulum with a rolling wheel, which combines translational and rotational motion. The system's dynamics are described by a set of coupled differential equations that are challenging to solve analytically using traditional methods. To overcome this challenge, the variation iteration method (VIM) is employed to derive an analytical solution. VIM is a powerful technique that allows for the approximate solution of differential equations by constructing a series solution iteratively. The Lagrange multiplier, a crucial component in the solution process, is determined for the first time using the Elzaki transformation. Interestingly, the Lagrange multiplier obtained through the Elzaki transformation matches the result obtained from Laplace transformation, which is a fundamental finding of this paper. Also we compared its results with the by employing the VIM and the derived Lagrange multiplier, a comprehensive analytical solution for the complex pendulum with a rolling wheel system is obtained. The solution provides insights into the system's behavior, such as the oscillation amplitudes, angular velocities and other relevant dynamic parameters. The proposed approach demonstrates the efficacy of the VIM in tackling complex mechanical systems and showcases the equivalence between the Lagrange multiplier derived through Elzaki transformation and the well-established Laplace transformation. The results obtained from this study contribute to the understanding and analysis of coupled translational and rotational systems, providing a valuable tool for researchers and engineers working in the field of mechanical dynamics. Sketches are made of the phase portraits close to the equilibrium points. [ABSTRACT FROM AUTHOR]

In this paper, the variational iterative method (VIM) with the Laplace transform is utilized to solve the nonlinear problems of a simple pendulum and mass spring oscillator, which corresponds to the Duffing equation. Finding the Lagrange multiplier (LM) is a significant phase in the VIM, and variational theory is frequently employed for this purpose. This paper demonstrates how the Laplace transform can be utilized to locate the LM in a more efficient manner. The frequency obtained by Laplace-based VIM is the same as that defined in the already existing methods in the literature in order to ensure the clarity of the results. Numerous analytical techniques can be used to solve the Duffing equation, but we are the first to do it using a Laplace-based VIM and a distinctive LM. The fundamental results of my paper are that LM is also the same in the Elzaki transformation. In the vast majority of instances, Laplace-based VIM only requires one iteration to arrive at an answer with high precision and linearization, discretization or intensive computational work is required for this purpose. Comparing analytical results of VIM by Laplace transform to the built-in Simulink command in MATLAB which gives us the surety about the method's applicability for solving nonlinear problems. Future work on the basic pendulum may examine the effects of nonlinearities and damping on its motion and the application of advanced control mechanisms to regulate its behavior. Future research on mass spring oscillators could examine the system's response to random or harmonic input. The mass spring oscillator could also be used in vibration isolation to minimize vibrations from one building to another. [ABSTRACT FROM AUTHOR]

The central purpose of this paper is to explore the nonlinear dynamics of the (2+1)-dimensional Kadomtsev–Petviashvili equation (KPE). The multiple soliton solutions (MSSs) are constructed via applying the Hirota method. Then the soliton molecules on the (x , y) -, (x , t) - and (y , t) -planes are extracted via imposing the velocity resonance conditions to the MSSs. Eventually, two effective techniques, the sub-equation approach (SEA) and the variational approach (VA), are employed to probe some other diverse wave solutions, which are the bright wave, dark wave, singular wave and the singular periodic wave solutions. The dynamics of the extracted solutions are unveiled graphically to exhibit the physical attributes. The attained solutions in this paper can enlarge the exact solutions of the (2+1)-dimensional KPE and enable us to understand the nonlinear dynamic behaviors better. [ABSTRACT FROM AUTHOR]

This study purposes to extract some fractional analytical solutions of the Peyrard-Bishop-Deoxyribo-Nucleic-Acid (β -PBDNA) dynamic model with the beta-derivative by the unified Riccati equation expansion method (UREEM). Furthermore, we examine the role of various parameters of the fractional model on the soliton dynamic. The research focuses on computational biophysics and materials science, examining the impact of various parameters on the fractional model. This paper contributes to understanding soliton solutions and the β -PBDNA dynamic model, demonstrating the applicability of the UREEM method to various fractional models. Some soliton solutions of the model are successfully generated by applying the UREEM. Implementing the UREEM, we take a fractional wave transformation to convert the model into a nonlinear ordinary differential equation. So, a linear equation system is generated. After the system is solved, the soliton solutions are gained for the appropriate solution sets. Finally, 3D, 2D and contour graphs of diverse solutions are depicted at suitable values of parameters. In addition, this paper presents 3D, 2D and contour graphs of various solutions with suitable parameter values. The results are beneficial for interpreting the model in future work and confirm that UREEM is effectively applicable to diverse fractional models, coupled with a comprehensive graphical analysis of how different parameters influence these solutions. [ABSTRACT FROM AUTHOR]

In this paper, we analyze how Eyring fluid film behavior on a vertically upward moving slippery flat plate can help predictive models in engineering, notably in coating and lubrication operations. This paper deals with the stagnant points and uniform film analysis of Eyring fluid film flow on a vertically upward moving slippery flat plate. The formulated ordinary differential equation is solved for exact analytic solution. Exact analytic expressions for velocity, flow rate, average velocity, shear stress components, and stagnant points are derived. A highly nonlinear algebraic equation is derived for film thickness. Equation is solved by Newton's method using Maple code. The thickness of film widens with increasing relaxation time, constant plate velocity, and fluid density, while it decreases with increasing fluid viscosity and constant slip parameter. The analysis delineates that the positions of stagnant points tend to relocate closer the slippery plate as the Stokes number, Deborah number, and constant slip parameter increase. A high Deborah number enhances drainage, causing stagnant points to relocate closer to the slippery plate and the development of a stable elastic layer adjacent to the plate. For stagnant points and fluid film thickness, a comparison between the Eyring fluid and existing studies (EPTT, LPTT, UCM, and Newtonian fluid) is also provided. The validity of this paper with the existing studies is also presented by reducing Eyring fluid model to Newtonian model. The results of this research are significant for a wide range of biofluid applications, including agrochemical uses, paint and surface coating flow behavior, thin films on the cornea and lungs, and chemical and nuclear reactor design. [ABSTRACT FROM AUTHOR]

Of current interest, there have recently appeared a series of the shallow-water papers in Mod. Phys. Lett. B. Illuminated by those papers and to make the story more complete, for the nonlinear long waves in the shallow water, this paper is scheduled to investigate a (2+1)-dimensional generalized Broer-Kaup system. As for the wave height and wave horizontal velocity, we employ symbolic computation, with the view of constructing out two groups of the similarity reductions. [ABSTRACT FROM AUTHOR]

This paper focuses on the application of an efficient technique, namely, the fractional natural decomposition method (FNDM). The numerical solutions of the model containing the water transport in unsaturated porous media, called Richards equation, are extracted. This model is used to describe the non-locality behaviors which cannot be modeled under the framework of classical calculus. To demonstrate the effectiveness and efficiency of the scheme used, two cases with time-fractional problems are considered in detail. The numerical stimulation is presented with results accessible in the literature, and corresponding consequences are captured with different values of parameters of fractional order. The attained consequences confirm that the projected algorithm is easy to implement and very effective to examine the behavior of nonlinear models. The reliable algorithm applied in this paper can be used to generate easily computable solutions for the considered problems in the form of rapidly convergent series. [ABSTRACT FROM AUTHOR]

In this paper, a triple-layer grating beam splitter with three-port output is designed. Through the combination of rigorous coupled-wave analysis (RCWA) and simulated annealing algorithms (SAA), the calculation and optimization of each parameter of the grating is carried out to make the diffraction efficiency of the grating meet the conditions. At the incident wavelength of 800 nm, the diffraction efficiencies of 0th order and ±1st order under TE polarization are 31.6% and 31.4%, respectively. The diffraction efficiencies of 0th order and ±1st order under TM polarization are 32.7% and 32.5%, respectively. It can be seen that not only the total diffraction efficiency under TE polarization and TM polarization exceeds 90%, but also the uniformity of diffraction efficiency at each order exceeds 99%. Finally, the influence of grating parameters and incident wave characteristics on diffraction efficiency is discussed. [ABSTRACT FROM AUTHOR]

The coupled nonlinear Schrödinger (CNLS) system is often used to describe physical problems such as wave propagation in a birefringent optical fiber. Under investigation in this paper is the nonlocal -symmetric reverse-space type of CNLS system, through constructing two types of Darboux transformation (DT), we will derive a new series of nonlocal analytic solutions: (1) Single-periodic and double-periodic solutions; (2) Four different combinations about dark and anti-dark solitons, as well as the bright and dark breathers on a periodic background. Moreover, the fundamental properties and dynamical behaviors of those solutions will be discussed. [ABSTRACT FROM AUTHOR]

In this paper, La 1 − x CaxFeO3 (x = 0 , 0.1, 0.2, 0.3, 0.4, 0.5) perovskite samples were synthesized by sol–gel method. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Mössbauer were used for measuring. XRD measurement shows that the unit cell volume of LaFeO3 gradually decreases with increasing Ca content. The morphology of the sample was observed by TEM, and there were significant changes in volume and size of the samples with different calcium contents. Mössbauer spectrum study found that with the gradual increase of Ca content, Fe 3. 5 + and Fe 4 + were formed in the sample. The study in this paper will provide a reference for future research on the effect of different calcium contents on the electronic structure of lanthanide ferrite. [ABSTRACT FROM AUTHOR]

Dynamic quantum secret sharing occupies an important position in quantum cryptography. In this paper, an efficient and secure dynamic quantum direct two-secrets sharing scheme is proposed based on the GHZ state. The proposed scheme is a one-time sharing of a determined classic message and quantum states. For recovering the secret messages, the agents only need to have the ability to perform X-basis measurements on the particles without performing any unitary operation. When dynamically deleting agents, our scheme only requires the other agents to announce some information without transmitting any quantum. Moreover, the analysis shows that our scheme is able to resist dishonest revoked agent attack as well as a range of other common attacks. Compared with the existing dynamic quantum direct secret sharing schemes, the proposed scheme is more efficient and more secure. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel, simple and accurate analytical study based on nonlocal elasticity theory to forecast small-scale effects on the radial vibration of anisotropic gold nanospheres submerged in viscoelastic fluid (VEF). Eringen's model is used to determine the motion equation for anisotropic nanospheres, with the fluid assumed to be viscoelastic and compressible. The frequency equation is derived by imposing the fluid-nanosphere interface continuity conditions. A comparison with the literature results is conducted to demonstrate the validity and correctness of this analysis, which indicates a very good agreement. The importance of small-scale effects in the radial vibration, which need to be included in the nonlocal elasticity model of submerged nanospheres, is eventually revealed by numerical examples. It is discovered that the nanosphere size, nonlocal parameter, and glycerol–water mixture have a significant impact on the vibration behaviors. Our results show that the small scale is crucial for the radial vibration of gold nanoparticles when the gold nanosphere is smaller than 5. 5 nm. Thus, the resulting frequency equation is very useful to interpret experimental measurements of the vibration characteristics of submerged gold nanospheres in VEF. [ABSTRACT FROM AUTHOR]

In this paper, we analyze quantum walks on cycles with an absorbing wall. We set the absorbing wall on cycles with N vertices (where N is an even number), and divide | φ (t) 〉 into two parts, L (t) and R (t). Due to the periodicity of the cycles, the condition L (M + N) = L (M) (or R (M + N) = R (M)) is applied to L (t) and R (t) , then the transmission probability P M and reflection probability Q M at the absorbing wall n = M (M = N 2) at time t are obtained. Furthermore, we show that over time, the absorbing wall absorbs less and less. [ABSTRACT FROM AUTHOR]

Gas sensors are essential devices to detect harmful gases that are present in the environment. Metal oxide semiconductors (MOSs) are used as sensing materials to detect harmful gases. Some of the metal oxides, like ZnO, SnO2, WO3, NiO, etc. have been used to detect the gases. This paper provides a theoretical study of gas sensing using MOSs. Many programs are available for the theoretical Density Functional Theory (DFT) approach. The theoretical calculation provides many properties about the sensing material, like electronic properties, magnetic properties, charge difference calculation, and Vander wall interaction between the sensing material surface and adsorbing molecule. The nanostructure provides better gas sensing performance due to its high surface-to-volume ratio. This paper is based on the DFT study and provides gas-sensing results using electronic properties. [ABSTRACT FROM AUTHOR]

In this paper, we study the localization of an electron in a binary quantum system formed by a pair of quantum dots (QDs). The traditional theoretical consideration of such systems is limited to the symmetrical case when QDs in such double quantum dot (DQD) are assumed identical in all respects. In this paper, we model the effects of breaking QD similarities in a DQD by studying two-dimensional (2D) DQDs as a double quantum well (DQW). This is done by solving the Schrödinger equation, with parameters chosen to describe an InAs/GaAs heterostructure. We calculate the energy spectrum of the electron confinement and the spectral distribution of localized/delocalized spatial states. Both symmetric and asymmetric QW shapes are considered and their effects are compared. The effects of symmetry breaking are explained within the framework of the two-level system theory. We delineate the QW weak and strong coupling cases in DQW. In particular, we show that the coherence in ideal DQW is unstable in the case of a weak QW coupling. Within the framework of the proposed approach, a charge qubit realized on a DQD is discussed and, as an example, a qubit based on an almost ideal DQD is proposed. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of the dielectric constant of solutions of a polar liquid in a nonpolar solvent: chlorobenzene–benzene, chlorobenzene–hexane. The measurements were carried out at a wavelength λ = 1 2. 8 0 cm in the temperature range from − 8 0 ∘ C to 2 0 ∘ C. The studies were carried out using the dielectric spectroscopy method. This method allows a more detailed study of the dielectric properties of the objects of study due to the large equilibrium ("static") dielectric constant of the object. The temperature dependence of the dielectric relaxation time of molecules in the liquid and solid states of the studied solutions is determined. It has been established that with increasing concentration (0.300, 0.562, 0.794, 1.000 for a chlorobenzene–hexane solution and 0.179, 0.368, 0.567, 0.778, 1.000 for a chlorobenzene–benzene solution) of the halogen substituent, the relaxation time increases. The measurement results of dielectric constant ε ′ and absorption coefficient ε ′ ′ obtained for concentrated solutions chlorobenzene–benzene, chlorobenzene–n–hexane at wavelengths λ = 1 2 , 80 and λ = 3 , 2 6 cm at temperature 2 0 ∘ C are given in the paper. The static dielectric constant is obtained at a frequency of 1 MHz. The obtained experimental values ε ′ , ε ′ ′ and ε 0 of investigated systems in ( ε ′ , ε ′ ′ ) plane locate on the semi-circle the center of which is on ε ′ axis. In this case, the high-frequency limit value of ε ∞ dielectric coefficient exceeds the corresponding n2 refraction index square. The macroscopic and molecular relaxation times are calculated on the base of experimental data. The thermodynamic quantities characterizing the process of dielectric relaxation are calculated for solutions of chlorobenzene–benzene, chlorobenzene–hexane. It has been determined that the height of the potential barrier separating the two equilibrium positions of a polar molecule is greatest in the state of a pure polar liquid and decreases with dilution in a nonpolar solvent. [ABSTRACT FROM AUTHOR]

In the 21st century, understanding the mechanism of high-temperature superconductivity has emerged as a pinnacle achievement in condensed matter physics, capturing the lifelong interest of numerous physicists. This paper endeavors to offer a theoretical elucidation for this mechanism, advancing the broader field of physics. Recognizing that high-temperature superconductivity is an aspect of condensed matter physics — underpinned by Maxwell's classical electromagnetic theory — we turn to theoretical mechanics and field theory, which are foundational perspectives in the contemporary scientific era. By framing Maxwell's classical electromagnetic theory within the context of theoretical mechanics and field theory, this paper not only sheds light on the mechanism of high-temperature superconductivity but also recasts Maxwell's theory within a purer theoretical mechanics and field theory domain. This represents a paradigmatic shift and cognitive transformation in physics. Furthermore, leveraging this theoretical mechanics and field theory interpretation of electromagnetic phenomena, we discern that electromagnetic phenomena can be more aptly explained without resorting to the concepts of charges and electric fields, leading to a reinterpretation of Coulomb's law. We propose that protons and electrons might exist as entities devoid of charge-specific attributes and negate the possibility of a strongly correlated particle system within them. [ABSTRACT FROM AUTHOR]

This paper presents an analytical solution to the model. By solving the system of nonlinear reaction-diffusion equations using Akbari–Ganji's method (AGM), we can derive the semi-analytical expressions for substrate and oxidized and reduced mediator concentrations. These models provide information about enzyme electrode mechanisms and their kinetics. These modeling results can be helpful for sensor design, optimization, and determining how the electrode will react. Further, we studied the effects of many physical and biological parameters on model prediction. The mathematical equations, which are nonlinear partial differential equations, are solved using AGM. Also, we derived the semi-analytical results for concentrations for saturated and unsaturated kinetics. It is verified that the proposed solution is validated by comparing it with numerical solutions. [ABSTRACT FROM AUTHOR]

In this paper, a pulsatile flow of a biviscous fluid in a circular tube of varying cross-section has been considered for investigation. The study helps to draw the characteristics of blood, the pressure drop and the wall shear stress on the inner wall of small blood vessels and capillaries where suction/injection velocity arises and Reynolds number is very low. The effects of Reynolds number, apparent viscosity coefficient and leakage parameter on the streamlines, pressure drop and wall shear stress have been discussed and shown graphically for suction and injection, respectively. The wall of the tube is supposed to be permeable and a normal velocity of the fluid at the wall is prescribed to consider the fluid exchange across the wall. Both analytic and numerical solutions are given. Using the perturbation technique, we analyze the problem for low Reynolds numbers and small oscillation amplitude. Lastly, the simulations are given to demonstrate the effectiveness and excellent tracking performance of the proposed control scheme. [ABSTRACT FROM AUTHOR]

A seven-port division is described via the connecting-slab-based reflective grating in this paper. The rigorous coupled wave analysis (RCWA) and simulated annealing algorithm (SAA) are chosen to analyze and optimize the performance of the grating. The total diffraction efficiency of TE and TM polarization is 96.75% and 95.53%, respectively. Besides, the target grating has good uniformity errors, which are reduced to 3.69% and 1.76% for TE and TM polarization, respectively. The modal method provides a physical explanation for the energy transformations within the target grating. Furthermore, the manufacturing tolerance is discussed for the seven-port division grating. Through analysis and discussion, various performances of the grating can be better demonstrated. Compared with most seven-port grating splitters reported previously, the grating in this paper achieves better diffraction efficiency uniformity and higher efficiency. [ABSTRACT FROM AUTHOR]

This research paper examines the Darcy–Forchheimer flow of second-grade hybrid nanofluid with thermophoretic particle deposition on a solar collector plate in a porous media. This study performs an extensive exploration of entropy generation. Solar collector plates play a crucial role in energy storage in solar power plants. They help to store and regulate energy at extreme temperatures. This work analyzes the performance of a solar collector plate when the conventional fluid of Ethylene Glycol (EG) is reciprocated by nanoparticles of zirconium dioxide and copper. The ramifications of Magntohydrodynamic (MHD) and Cattaneo–Christov heat and mass flux are also investigated. The expressions of mass and energy are generated by using the Cattaneo–Christov model of heat and mass flux. The Homotopy analysis method (HAM) is utilized to achieve the results of differential equations against various dimensionless parameters. The fluctuating behavior of velocity, concentration and temperature profiles is discussed graphically in this paper. Furthermore, tables are included for the numerical values of skin friction, Sherwood number and Nusselt number for several parameters. As the value of the Darcy parameter raises, the fluid's velocity distribution continuously reduces. The temperature distribution reduces along with the greater values of the thermal relaxation parameter. The concentration profile has shown decreasing impact due to the increasing value of the concentration relaxation parameter. [ABSTRACT FROM AUTHOR]

Some times ago, in the framework of the Boltzmann kinetic equation in the so-called τ -approximation, it was shown that perpendicular resistivity in quasi-two-dimensional (Q2D) conductors can be impurity independent in a broad range of high parallel magnetic fields [A. G. Lebed and N. N. Bagmet, Phys. Rev. B 55 (1997) R8654]. In this paper, we demonstrate that this result is much more general than the Boltzmann kinetic equation in the τ -approximation and is valid in a pure Q2D metal at low frequencies of the electric field. The above-mentioned statement open possibilities to test the above discussed phenomenon in a number of Q2D organic, high-Tc, and some other Q2D superconductors in their metallic phases and gives a method to extract some important information about their Q2D Fermi surfaces. [ABSTRACT FROM AUTHOR]

In this paper, a five-order Korteweg–de Vries (KdV) equation is studied, which is used to describe the nonlinear phenomena in the fluids, especially those of the surface gravity waves and internal waves in the stratified fluids. (a) Via the symbolic calculation, this KdV equation cannot pass the Painlevé test without any constraint conditions. By virtue of the ansatz method, bell-shape and kink soliton solutions of this KdV equation are attained. (b) Via the bilinear method, multisoliton solutions of this KdV equation are obtained under some constraint conditions. Propagation and interaction of the multisoliton are discussed. Soliton interaction is elastic, that is to say, they have no effect on each other's amplitude and speed except for phase shift. We hope that our results will be useful for experimental studies of surface gravity waves and internal waves since the coefficients of this KdV equation are all expressed in terms of physical constants, depths, and densities of the fluid. [ABSTRACT FROM AUTHOR]

In this paper, we use a novel approach to study the existence, uniqueness, and stability of solutions (EUSS) to a Cauchy-type problem of nonlinear fractional differential equations (FrDiEq) of variable order with infinite delay (CPNFDEVOID). Contrary to the techniques taken in the literature, which were centered on the usage of the concept of generalized intervals and the idea of piecewise constant functions, our approach is straightforward and based on a novel fractional operator that is more appropriate and demonstrates the solvability and stability of the main problem under less restrictive presumptions. The results are achieved in this paper by using Fixed Point Theory (FPT). The application, which includes an example and supporting images, concludes the paper. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of the magnetic and magnetocaloric properties of a mixed Graphullerene-like nanostructure. The Blume–Capel model is employed, and Monte Carlo computations were performed using the Metropolis algorithm. The study examines various spin configurations within different parameter planes and reveals stable configurations. Furthermore, the paper analyzes magnetizations, susceptibilities, specific heat, and Binder cumulant as a function of the temperature to determine the transition temperature and characterize magnetic phase transitions in the system. The suitability of the investigated structure for magnetic refrigeration was also assessed by examining the magnetic entropy change and relative cooling power at different external magnetic field strengths. The results show a direct correlation between the external magnetic field and maximum entropy changes, indicating a significant magnetocaloric effect. [ABSTRACT FROM AUTHOR]

This paper presents a low dropout bandgap voltage reference circuit that combines high output voltage accuracy and low temperature-coefficient in a wide temperature range. The low temperature-coefficient is achieved by an advanced high-order curvature compensation technique, which is implemented by a novel exponential piecewise compensation term in a high-temperature range. A supply noise self-regulation technique is proposed to realize an excellent power supply rejection ratio (PSRR) without using any amplifiers in this paper. The proposed high-accuracy voltage reference is designed in a 2 μ m bipolar process. The circuit generates a reference voltage of 3.3 V and can operate under a minimum supply voltage of 3.8 V, while consuming 44.8 μ A. The output voltage accuracy is ± 0.15%. The PSRR at 10 Hz and 1 MHz is − 6 4 dB and − 7 8 dB, respectively. The line regulation is 2.45 ppm/V in a supply voltage range from 3.8 V to 20 V. The average temperature coefficient is 11.9 ppm/∘C in a temperature range from − 5 5 ∘ C to +125∘C. [ABSTRACT FROM AUTHOR]

Non-Newtonian fluids display fascinating and versatile flow behavior, enabling applications in fields where precise control and manipulation of viscosity are required. This paper presents the rheology of Homann stagnation point flow for a Jeffrey fluid containing gyrotactic microorganisms over a biaxially stretching surface. The system of equations is solved numerically using appropriate similarity transformations and conditions. The boundary conditions are set to maintain a fixed physical environment, and the far field values are defined accordingly. The dual solutions are found and expressed in terms of relevant quantities, and their behavior is analyzed using graphical representations via bvp5c. Stability analysis is conducted as well. The model is extended to study the behavior of Jeffrey nanofluids under the influence of various physical phenomena such as thermophoresis, Brownian motion, Ohmic heating, heat source/sink, radiation, and chemical reaction. The model presented in this paper can help researchers predict and optimize the behavior of such systems for a range of industrial and biomedical applications. It is observed that when the smallest eigenvalue is positive, the disturbance initially decreases, and the flow is stable, otherwise unstable. The stretching/shrinking parameters affect the flow field and boundary layer characteristics, leading to changes in the skin friction forces and an increase in the skin friction coefficient. Moreover, the Peclet number augmented the concentration of microorganisms due to gyrotactic bioconvection for first and second solutions, whereas bioconvective Lewis number shows an opposite trend. The comparison of the present results, as a simplified case, with existing literature demonstrates good agreement. [ABSTRACT FROM AUTHOR]

In this paper, the effects of transition metal doping on the electronic structure of monolayer NbS2 were studied through the first principles. The electronic structure changes caused by doping transition metal (TM) atoms were recorded, including the energy band, the density of states, binding energy, and optical properties. Studies show that all doping systems are metal. Still, under strain regulation, some doping systems offer an indirect bandgap; NbS2 transforms into a narrow bandgap diluted semiconductor and can improve the activity. Doping atoms lead to n (p) type doping in NbS2. Regarding optical properties, IVB group metals are selected as the typical dopant of three periods. Composite NbS2 has excellent reflector characteristics and can be applied to infrared and ultraviolet regions. The spectral response and electromagnetic wave absorption range of low-energy areas are also improved. This study effectively solves the problem of impurity states introduced by doping and provides a solution for the doping modification of monolayer NbS2, which will lay a foundation for nanoelectronics. [ABSTRACT FROM AUTHOR]

In this paper, the effects of the thermostability, band structure, and the external electric field on the electronic structure of MoSe2/Arsenene heterojunction are calculated based on the density functional theory. The calculation results show that the MoSe2/Arsenene heterojunction is a type-II heterojunction with a bandgap of 0.89 eV. When MoSe2 and arsenene combine by van der Waals force, the electrons are transferred from MoSe2 to arsenene, the holes are transferred from arsenene to MoSe2, with the direction of the internal electric field from MoSe2 to arsenene. The MoSe2/Arsenene heterojunction with valence band top and conduction band bottom contributed by arsenene and MoSe2, respectively, shows excellent thermostability at room temperature. The external electric field can effectively modulate the electronic structure of heterojunction. When the electric field is negative, electrons are transferred from MoSe2 to arsenene and holes from arsenene to MoSe2. The Fermi level of arsenene moves down while that of MoSe2 moves up. When the electric field is positive, the direction of electron and hole transfer are opposite to that when the electric field is negative. The Fermi energy level of arsenene and MoSe2 also move in the opposite direction. [ABSTRACT FROM AUTHOR]

This paper presents the elastic deformation and thermodynamic theory for crystals with HCP structure on the basis of the statistical moment method (SMM) together with numerical results and discussions for metals Mg, Zn, Dy, Er and Gd. Some numerical results are compared with experiments and other calculations. [ABSTRACT FROM AUTHOR]

Machine learning is emerging as a new approach that provides more options for solving complex problems involving electromagnetic phenomena. This paper evaluates the application of machine learning to the design of graphene-based absorbers, which is a research challenge. Five machine learning algorithms — k -nearest neighbor regression (kNN), artificial neural network (ANN), decision tree (DT), extremely randomized trees (ETs) and random forest (RF) — are applied to realize the transmission spectrum prediction and reverse design of a graphene nanoribbon waveguide side-coupled absorber. The results show that all five algorithms are effective, with RF being the most accurate in the inverse design. Compared with previous work, the application of machine learning in the intelligent design of graphene absorbers is evaluated more comprehensively, providing a reference for the selection of machine learning algorithms for future inverse design problems. [ABSTRACT FROM AUTHOR]

The major theme of this research is to develop the numerical scheme for the computation of nonlinear problems by the implementation of the boundary element method dependent on Taylor's series. This paper deals with the problem of laminar flow in a semiporous channel in the presence of a transverse magnetic field and the homotopy analysis method (HAM) is employed along with the general boundary element method to compute an approximated solution of the system of nonlinear differential equation governing the problem concerned. A well-known and useful nonlinear differential equation of fluid mechanics F (3) (η) + 1 2 F (η) F (2) (η) = 0 with the boundary conditions F (0) = 0 = F (1) (0) , F 1 (∞) = 1 is referred as an example to show a glimpse into the basic idea of the method and technique used in this paper. It shows the capabilities and wide range of applications of HAM using Taylor series expansion of the derived integral equation. A comparison of HAM with the results calculated previously has been discussed. The solution obtained with HAM in comparison with the numeric solution shows remarkable accuracy. Root mean square formula is computed for the convergence analysis at various values. An increment in the number of elements depicting the convergent results as error is decreased. [ABSTRACT FROM AUTHOR]

This paper explores the dynamic behavior of the (2 + 1) -dimensional Boussinesq equation, which is a nonlinear water wave equation used to model wave packets in dispersive media with weak nonlinearity. Specifically, we investigate the equation's traveling wave solutions using the Riccati equation mapping method. Our results include solitary and soliton solutions, each with their own set of parameter values. To provide a comprehensive understanding of these solutions, we present them in general form and visualize their significance using various graphs, such as 3D, 2D, and contour plots. The computational effort and resulting outcomes highlight the efficacy of our approach, which has the potential to be applied to other nonlinear physical problems in fields such as mathematical physics, engineering, and nonlinear science. [ABSTRACT FROM AUTHOR]

The phenomenon of free convection above an isothermal vertical cone in the flow of Newtonian fluid suspended with solid nanoparticles like silver (Ag) and magnesium oxide (MgO) is numerically analyzed in this paper. Here, a convectively heated vertical cone is immersed in the infinite nanofluid with a porous medium. The fluid motion occurs due to the thermal gradient and force of gravity in the system. Energy transportation is studied with help of the empirical theory of Cattaneo–Christov. The physical effects included in the problem are heat source, stratification, chemical reaction, and motile microorganism. Further, the total entropy rate is computed. The flow, temperature, concentration, and microorganism distribution are explored in view graphical abstracts which are computed numerically by integration of the governing non-linear system of equations using the bvp4c technique. The outcomes are validated by relating them to earlier available data in the field, which is a remarkable feature of the proposed model. In this feature, an admired balance has been attained. The investigation proves that the buoyancy ratio characteristic and bioconvection Rayleigh number reduce the fluid velocity. Further, the concentration and microorganism stratification parameter effect diminish the motile microorganism and concentration distribution. [ABSTRACT FROM AUTHOR]

This research paper presents an investigation into the behavior of rarefied flow and heat transfer in a rectangular microchannel utilizing a Cu-water nanofluid. The study employs the thermal lattice Boltzmann method (LBM) with a lattice featuring a double distribution function and a BGK collision model. The simulations are performed using Python software, incorporating slip velocity and temperature jump effects. The primary objective is to analyze the influence of various thermophysical parameters of the coolant fluid on the microchannel, specifically focusing on the characteristics of the Cu-water nanofluid. The study considers laminar flow conditions with nanofluid volume fractions of 2%, 4% and 6%. The findings reveal that both rarefaction effect and Reynolds numbers, as well as the nanoparticle volume fraction, significantly impact the system. Moreover, the investigation evaluates key parameters such as the Nusselt number, skin friction coefficient, temperature jump slip velocity and velocity and temperature profiles. Notably, the nanoparticle volume fraction exhibits minimal influence on the velocity distribution or temperature field, whereas the Nusselt number increases with higher nanoparticle volume fractions. Additionally, the rarefaction effect leads to a reduction in velocity and temperature. At a nanoparticle volume fraction of 2%, increasing the Reynolds number results in elevated velocities and lower temperatures. The skin friction coefficient displays a decreasing trend along the microchannel with increasing Reynolds numbers. Furthermore, an increase in Knudsen numbers corresponds to a decrease in the skin friction coefficient. Finally, an increase in the nanoparticle volume fraction is associated with a decrease in the skin friction coefficient. [ABSTRACT FROM AUTHOR]

The Zakharov–Kuznetsov (ZK) equation is extensively investigated in this study. This equation is a two-dimensional (2D) generalization of the well-known Korteweg–de Vries (KdV) equation, which is spatially limited as the 1D model of weakly nonlinear waves in shallow water. In this paper, we use three different methods to solve the conservation laws of it. First, the direct construction method is used to calculate the multipliers of the objective equation, and the conservation laws can be obtained by using the multipliers. Then its strict self-adjoint property is verified, and its conservation laws are solved by Ibragimov's method. Finally, the conservation laws of the target equation are solved by Noether's theorem. Then we calculate some exact solutions of the ZK equation by the extended Kudryashov method and seek a few solutions in terms of hyperbolic tangent functions and exp (ξ). Meanwhile, the conservation law analysis of the target equation is carried out, and its Lie point symmetries, reduced order form and invariant solution are determined. In the end, the Hamiltonian structure of the target equation, the generalized pre-symplectic that maps symmetries into adjoint-symmetries and some of its soliton solutions are calculated. [ABSTRACT FROM AUTHOR]

In this paper, the finite element method is used to investigate the sound absorption performance of the micro perforated plates (MPPs) with acoustic black hole (ABH) back cavities. First, the finite element models of MPPs with sealed back cavities and ABH back cavities are developed. The simulation results show that the absorption bandwidth of ABH back cavities increases by 63.8% compared to the sealed back cavity of the same size, but the frequency of the highest absorption coefficient is increased. Second, the mechanism for expanding the band width is illustrated by the pressure distribution inside two cavities. Finally, the effect of different cavity numbers of stages and lengths on the sound absorption performance is analyzed. This study broadens the application scenario of MPPs by incorporating ABH back cavities and can provide a reference value for acoustic modulation. [ABSTRACT FROM AUTHOR]

In this paper, we discuss a proposal for the transfer of states belonging to the W-type states by executing a controlled teleportation protocol. A 7-qubit quantum entangled resource shared between the sender, receiver and controller is utilized in this protocol. The scheme proposed here is a perfect communication scheme where the task of quantum state transfer is performed with certainty. Further, a protocol for the generation of the quantum resource used here is designed and run on IBM platform. Additionally, we consider the effect of four types of noises, namely, amplitude-damping noise, bit-flip noise, phase-flip noise and phase-damping noise on our protocol. The efficiency of the protocol is compared with other similar protocols which shows that the present one is better performing. [ABSTRACT FROM AUTHOR]

This paper presents a performance analysis of indium-gallium-zinc-oxide (IGZO)- and pentacene-based top-gate-top-contact (TGTC) and bottom-gate-top-contact (BGTC) thin film transistors (TFTs). Extensive simulation has been performed to assess the performances in terms of threshold voltage, subthreshold slope, on-off current ratio, mobility, and figure of merit (FoM). Results indicate a trade-off between mobility and current ratio with respect to the permittivity of the dielectric layer, where tantalum oxide (Ta2O 5) provides the optimum result in terms of FoM. The mobility of IGZO is significantly higher for both structures, whereas the current ratio for IGZO is higher than pentacene in the BGTC configuration. Comparing the structural configurations, Ta2O5-IGZO-based BGTC achieves 5. 9 2 × and 4 1. 8 × better mobility and current ratio, respectively, over TGTC structures. The threshold voltage of IGZO-based TFT is observed to increase with the permittivity of the dielectric in TGTC configuration but decrease in BGTC configuration. Meanwhile, the increase in oxide and active layer thicknesses causes a decrease in the threshold voltage. Moreover, both mobility and current ratio improve with a decrease in oxide or active layer thickness. Maximum mobility of 32.30 cm2/Vs and a maximum current ratio of 7.54E+08 are achieved for Ta2O5-IGZO-based BGTC TFT with 10 μ m channel thickness and 5 μ m oxide thickness. [ABSTRACT FROM AUTHOR]

In nature, living organisms move in a collective state of aggregation, this collective motion is influenced by the nature of the environment, the obstacles refocused during the movement and the local interaction between individuals, this interaction is responsible for avoiding collision between each individual. In this paper, we study numerically the collective motion of self-organized organisms by expanding the Langevin dynamics, in which we have modeled the interaction between individuals by an elastic force. Modeling the interaction between individuals using an elastic force gives remarkable results. This interaction has an important effect if the individuals are dispersed a lot in space, but if a certain number of particles N is exceeded, this force is of no importance and the saturation velocity becomes constant. The results of the numerical simulation show that the average velocity of the individuals goes through a transient regime before reaching the permanent regime. Moreover, the results show that the system represents a transition from a nonequilibrium state to an equilibrium state, which is similar to a second-phase transition (paramagnetic/ferromagnetic) in the absence of the magnetic field; this phase transition is observable if the distance between two individuals is greater than a critical radius noted R c . [ABSTRACT FROM AUTHOR]

This paper investigates the numerical analysis of a highly performed surface plasmon resonance (SPRE)-based sensor employing a hybrid structure of SrTiO3 (STO) and graphene for rapid detection of malaria. The investigation is performed using the angular interrogation technique and transfer matrix method. The SPRE device has a glass prism, silver (Ag), STO, graphene, affinity layer and sensing medium (SGM). Four coupling prisms are examined and we found the prism N-FK51A corresponds to the highest sensitivity. The sensitivity of the structure N-FK51A/Ag/STO/graphene/affinity layer/SGM is found to be 205.405, 222.222 and 2 5 8. 3 3 3 ∘ /RIU for Schizont, Trophozoite and Ring malaria stages. The layer thicknesses are then optimized and it is found that the proposed SPRE sensor can achieve a sensitivity of 278.378, 227.027 and 4 0 0 ∘ /RIU for Schizont, Trophozoite and Ring malaria stages with 30 nm (silver), 1 nm (STO), mono-sheet of graphene and 5 nm of the affinity layer. These findings demonstrate that the proposed method and structure can be used efficiently for biomedical applications. [ABSTRACT FROM AUTHOR]

Graphene has excellent mechanical properties and vibration frequency is an important mechanical property. In this paper, the effects of doping elements and doping concentrations on the vibration characteristics of graphene nanoribbons were investigated by molecular dynamics simulation. The vibration characteristics are influenced by the doping element, depending on the bond structural difference in bond structure between doping atoms and carbon atoms. The vibration frequencies of Nitrogen (N)-doped and Nitrogen–Nitrogen (N–N)-doped graphene nanoribbons are slightly lower than those of pure graphene nanoribbons. However, the vibration frequencies of Sulfur (S)/Phosphorus (P)-doped and Sulfur–Sulfur (S–S)/Phosphorus–Phosphorus (P–P)-doped graphene nanoribbons are significantly lower than those of pure graphene nanoribbons. In addition, with the increase of S (P) doping concentration, the vibration frequency of monolayer graphene nanoribbons decreases gradually. [ABSTRACT FROM AUTHOR]

Strain engineering is generally employed as an efficient means of tuning the physical properties of a target compound. In this research paper, we investigated the effect of three axial stretches on the structural, electronic, optical, and thermoelectric properties of inorganic Ge-based halide perovskites LiGeBr3. Computations were carried out using Density Functional Theory (DFT) and the semi-classical Boltzmann transport theories. The electronic investigation indicated that LiGeBr3 perovskite exhibits a direct bandgap of 0.480 eV. The findings suggest that the bandgap is highly responsive to strain, which improves the absorption ability in the visible light range (300–500 nm). The relative stability of the strained compounds and the feasibility of their synthesis were robustly demonstrated by the negative formation energies. The transport features were assessed as a function of temperature and yielded interesting results. The electrical conductivity was considerably enhanced under strain, and the highest figure of merit was found at low temperatures (approximately 0.741). Our theoretical discovery proved that strain is an enormously exciting technique for extending semiconductor applications and boosting thermoelectric and solar cell devices. [ABSTRACT FROM AUTHOR]

In this research paper, we numerically analyze the flow and heat transfer rate of non-Newtonian pseudo-plastic nanofluid with variable apparent viscosity and thermal conductivity effects, respectively, through annular sector duct. Concentric pipes annular sector duct of an apex angle, 2 β and ratio of radii, R ̂ , is filled with saturated porous media. For this purpose, we utilize the power law Darcy–Brinkman flow model along with Forchheimer term. Also, the contribution of nanoparticles is accounted in carboxy methyl cellulose (CMC)-water, which has been taken as base fluid. Finite volume method (FVM) is utilized to discretize the governing mathematical model, whereas algebraic equations are solved numerically by using strongly implicit procedure (SIP). With the help of graphs, the impacts of nanoparticles' contribution and porosity factor have been discussed by giving physical interpretation. Results are also found in the limiting sense and show the good agreement with already published data. At β = π / 3 , ϕ = 0. 1 0 , D a = 0. 0 1 and R ̂ = 0. 2 5 , we can observe down in f Re and Nu upto 5. 6 5 8 % and 1 0. 0 1 % , respectively, when n decreases from 1 to 0. 9 1 , whereas 1 3. 4 7 % and 2 3. 5 7 % , respectively, by decreasing the value of n from 1 to 0. 7 6. For both cases of nanoparticles' contribution, the downs in Nu have been observed same by decreasing the value of n. [ABSTRACT FROM AUTHOR]

In this paper, the structural, electrical and optical effects of WS2 doped with silicon atoms after torsional deformation are investigated using first-principles calculations. First-principles calculations for metal disulfide-WS2. The doping of Si atoms gives WS2 a tunable band gap, and the surface state is successfully transformed from a 2.0 eV band gap to a quasi-metal with a 0.254 eV band gap, and the change of the doped Si atoms causes a redshift in the absorption peak and a blueshift in the reflection peak. The band gap of WS2 can be effectively adjusted by torsional deformation on the basis of Si-doped atoms in the range 0.254–0.052 eV. Calculations of optical properties show that Si-doped WS2 with a torsion angle of 1 0 ∘ has the lowest light absorption peak and Si-doped WS2 with a torsion angle of 8 ∘ has the lowest light reflection peak. This paper opens up new possibilities for designing materials on demand. [ABSTRACT FROM AUTHOR]

Based on the magnetic dipole theory and the elastic mechanical plane strain method, this paper establishes a multi-chain model of ferromagnetic particle inclusions–superconducting matrix and investigates the effects of the distribution form of ferromagnetic particle inclusions and elastic parameters on the effective magnetostriction of superconductors. A dimensionless parameter is introduced to describe the spatial distribution form of ferromagnetic particles in the matrix, and the calculation is carried out using the elastic mechanical plane strain method. The change of the effective magnetostriction following the elastic parameter is given for three kinds of distribution forms: single-chain, planar–laminar, and spatial three-dimensional multi-chain, respectively. The results show that the distribution of ferromagnetic particle inclusions and the change of elastic parameters have a notable influence on the displacement and magnetostrictive distribution of superconductors. [ABSTRACT FROM AUTHOR]

Steering is a type of nonseparable quantum correlation, where its inherent asymmetric feature makes it distinct from Bell nonlocality and entanglement. In this paper, we investigate quantum steering in a two-mode Gaussian state ϱ ̂ c 1 c 2 coupled to a two-mode vacuum reservoir. The mode c 1  ( c 2 ) is emitted during the first (second) transition of a nondegenerate three-level cascade laser. By means of the master equation of the state ϱ ̂ c 1 c 2 , we derive the analytical expression of the steady-state covariance matrix of the modes c 1 and c 2 . Using realistic experimental parameters, we show that the state ϱ ̂ c 1 c 2 can exhibit asymmetric steering. Furthermore, by an appropriate choice of the physical parameters of the state ϱ ̂ c 1 c 2 , we show that one-way steering can be achieved. Essentially, we demonstrate that one-way steering can, in general, occur only from c 1 → c 2 . Besides, we perform a comparative study between the steering of the two laser modes and their Gaussian Rényi-2 entanglement. As a result, we found that the entanglement and steering behave similarly in the same circumstances, i.e. both of them decay under dissipation effect; moreover, they can be well enhanced by inducing more and more quantum coherence in the state ϱ ̂ c 1 c 2 . In particular, we found that the steering remains always less than the Gaussian Rényi-2 entanglement. [ABSTRACT FROM AUTHOR]