The growing demand for energy calls for efficient utilization of natural energy resources in developing useful work. Thermodynamic irreversibility deals with the disorderliness in any system. This work investigates the energy optimization of a cylinder experiencing stretching and rotation immersed with aluminum alloys (AA7072-AA7075) in engine oil-based nanofluid. The Maxwell nanofluid model is employed to check the thermophysical properties of nanofluids. Heat transfer occurred at the cylinder’s surface by considering the constant and prescribed temperature. Forced convection is due to a stretchable rotating boundary, while natural convection is owing to a thermal gradient in the system. The dimensionless ordinary differential equations are obtained by using the appropriate ansatz and solved numerically through the bvp4c technique. A comparison profile of constant wall temperature and prescribed surface temperature shows that entropy generation and Bejan number are reduced for the former and increased for the latter, while thermal transport exhibits an opposite behavior. The axial and azimuthal wall stress parameters diminished due to an increment in Reynolds number. The heat transport rate is comparatively higher for AA7075/Engine oil than AA7072/Engine oil.

Modern developments in nanotechnology have provided a fantastic foundation for creating a better ultra-high-performing coolant known as nanofluids for many applications in manufacturing and engineering. Numerous scholars have been drawn in by the hybrid nanomaterials’ capacity to improve heat transmission more to examine the working fluid. This study uses the mathematical solution to explore the effect of viscous dissipative on the radiative-convective Williamson hybrid nanofluid flow through an angled moving plate with a magnetic impression. Focusing on certain reasonable assumptions, a nonlinear partial differential equation system is developed and then numerically solved using the bvp4c method. It is thoroughly explained how a particular collection of distinctive factors affects the motion features, shear stress, temperature field profiles and heat transfer. The motion declined with increasing Williamson fluid for both stretching and shrinking surfaces. An upsurge profile for energy is showing for radiation impression. The shear rate falls with the inclined plate and increases with the buoyancy impression.

The inner barrier in stepped quantum wells, which embrace an intrinsic structural inversion asymmetry (SIA), offers more possibilities for the multi-band spin–orbit (SO) control. By varying the inner band offset δ, which adjusts the quantum confinement for electrons and also the SIA, we reveal that both the Rashba (αν) and Dresselhaus (βν) SO coeffcients of the two subbands exhibit contrasting dependence on δ. Also, α1 and α2 may have opposite signs, depending on the value of δ. By fine tuning the inner offset, there may even exist a scenario in which α2 identically vanishes but α1 is finite, offering a knob on how to subband-selectively suppress spin relaxation induced by SO coupling. In addition, by resorting to an external gate Vg, we reveal that in the regime of α1 and α2 having opposite signs, their magnitudes also vary with Vg in an opposite manner. This, together with the engineered inner barrier of stepped wells, will facilitate flexible spin manipulation. Finally, the interband SO couplings, which depend on the spatial overlap of wave functions of distinct subbands and the corresponding parities, are also discussed.

The evolution of the human mind through natural selection mandates that our conscious experiences are causally potent in order to leave a tangible impact on the surrounding physical world. Any attempt to construct a functional theory of the conscious mind within the framework of classical physics, however, inevitably leads to causally impotent conscious experiences in direct contradiction to evolution theory. Here, we derive several rigorous theorems that identify the origin of the latter impasse in the mathematical properties of ordinary differential equations employed in combination with the alleged functional production of the mind by the brain. Then, we demonstrate that a mind–brain theory consistent with causally potent conscious experiences is provided by modern quantum physics, in which the unobservable conscious mind is reductively identified with the quantum state of the brain and the observable brain is constructed by the physical measurement of quantum brain observables. The resulting quantum stochastic dynamics obtained from sequential quantum measurements of the brain is governed by stochastic differential equations, which permit genuine free will exercised through sequential conscious choices of future courses of action. Thus, quantum reductionism provides a solid theoretical foundation for the causal potency of consciousness, free will and cultural transmission.

The present flow problem analyzes the impact of radiative heat and mass transfer with inclined magnetic field on thermal exchange and entropy production of two immiscible nature of electrically conducting couple stress fluid in a static porous saturated conduit. In this model, the lower and upper porous regions of the rectangular channel are occupied by two different types of couple stress fluids. The static horizontal parallel plates of the porous duct are completely isothermal and the flow of immiscible fluid through the porous duct develops because of a constant pressure gradient at the entry zone of the duct. The Brinkman model is utilized in the modeling of fluid flow through porous saturated domain and Rosseland’s approximation is utilized to compute the radiative thermal exchange effect on nonmiscible couple stress fluid. In this work, authors have analyzed the effect of various thermo-physical parameters such as the Hartmann number (Ha), permeability parameter (Da), Schmidt number (Sc), Soret number (Sr) and couple stress parameter (si,i=1,2) on the entropy generation characteristics, Bejan number distribution, thermal behavior, concentration distribution and flow characteristics of immiscible couple stress fluid which passes through the porous channel. The parameters Ha, Da, si, Sc, Sr correspond to magnetic field effect, permeability of porous media, couple stress, mass diffusion and thermal diffusion, respectively. The most significant findings of this research work are as follows:•In a porous saturated channel, the immiscible couple stress fluid velocity, entropy production number and thermal profile get enhanced on increasing the couple stress parameter.•On increasing the Hartmann number and decreasing the permeability of porous region, the thermal properties and entropy production number both decrease.•The couple stress fluid’s concentration field and Bejan number distribution get decreased on enhancing Soret number Sr and Schmidt number Sc.•The entropy generation near the wall of the channel rapidly increases on increasing the Schmidt number and Soret number.The emerging finding of this research work exhibits excellent agreement with previously published work. This research work can be utilized in food processing, petroleum products and chemical process.

In this paper, the spin wave theory is applied to the Heisenberg spin bilayer with intralayer ferromagnetic interaction J1, intralayer single-ion anisotropy D and interlayer antiferromagnetic interaction J2. It is found that the effects of both D and J2 on the thermodynamic quantities give rise to the two different low-temperature asymptotic behaviors with and without exponential law. For D>0, the interlayer antiferromagnetic interaction can induce the appearance of the maximum of the layer magnetization at finite temperatures. At the location of the layer magnetization maximum, the approximate behaviors (such as the power, linear, rational, exponential and logarithmic laws) which are driven by the temperature or the anisotropy, are obtained for the low-temperature thermodynamic properties. It is shown that the presence of antiferromagnetic interlayer interaction J2 clearly induces more quantum fluctuations than the case where the interlayer interaction J2 is ferromagnetic. Our results of the layer magnetization agree with the experimental data of the layered van der Waals crystal FeCl2 at low temperatures. In the monolayer case of J2=0, our results are in agreement with the findings obtained by the existing theories and the quantum Monte Carlo data.

In this study, we constructed a numerical technique for the simulation of the convection–diffusion problem under convection dominancy. Lagrange interpolation technique is applied to obtain new expressions for the approximation of variable at the interfaces of control volume. Moreover, based on these interface approximations new numerical scheme is developed to approximate convection–diffusion phenomena. The Crank–Nicolson approach is applied for the temporal approximation. This newly constructed numerical scheme is unconditionally stable with second-order accuracy in time and space both. Numerical tests are carried out for the justification of the new algorithm. A comparison of numerical results produced by proposed technique and some other numerical approaches is presented. This comparison indicates that for convection dominant phenomena, the numerical solution of conventional finite volume method contains with non-physical oscillations which analyze that proposed numerical technique results in a high accurate and stable solution.

In this paper, we explore how to generate solitary, peakon, periodic, cuspon and kink wave solution of the well-known partial differential equation Korteweg–de Vries (KdV) by using exp-function and modified exp-function methods. The presented methods construct more efficiently almost all types of soliton solution of KdV equation that can be rarely seen in the history. These methods appear to be straightforward and symbolic calculations are used to solve the problem. All resulting answers are verified for accuracy using the symbolic computation program with Maple. To show the physical appearance of the model, 3D plots of all the generated solutions are then displayed. The obtained solutions revealed the compatibility of the proposed techniques which provide the general solution with some free parameters. This is the key benefit of these methods over the other methods.

Natural convection takes up the attention of researchers due to its expansive industrial and engineering utilizations i.e., heat exchangers and electronic cooling. In this work, free convection of Cu-H2O nanoliquid flow and heat transfer (HT) in porous circular wavy domain under the internal heat generation has been perused by finite element method (FEM). The shape factor of nanomaterials is also considered. The influences of active factors like Rayleigh number Ra, nanofluid concentration, wavy wall’s contraction ratio A, number of undulations D, and shape factor of nanomaterials m are explored on flow and HT specifications. Moreover, the correlations for average Nusselt number Nuave have been attained with regard to impressive parameters of current study. Findings show that Nuave soars with soaring nanofluid concentration and nanoparticles’ shape factor. Further, the outcomes characterize that Nuave may lessen up to 15.11% and 9.95% by detracting A from 0.1 to 0.3 and by mounting D from 4 to 12, respectively.

As a new quantum state, topological insulators have become the focus of condensed matter and material science. The open system research of topological insulators has aroused the interest of many researchers. In this paper, we study the response of topological insulators to a single-mode quantized field with momentum. We solve the ground state of the system after the addition of a single-mode light field with adjustable photon momentum. To be specific, the analytical solution of Hall conductance has an additional correction compared with the closed system, and the Hall conductance can no longer be expressed by the weighted sum of the Chern numbers. Furthermore, the topological properties are analyzed and discussed through the results of an instance with their illustration. The system still has a topological phase transition and the critical point of the topological phase is robust to the single-mode quantized field.

Results of research in the quantum capacitance Cq of quasi-2D-crystals are presented. The detected extraordinary behavior of Cq manifests itself in the existence of such energy ranges in which it is practically equal to zero. The causes for the existence of such ranges are: (a) dimensional quantization as a result of the nanoscale of the van der Waals gap, (b) a certain value of the width of the allowed zone in the plane of the layers, which is determined by the value of the effective mass. Intercalation and external electric field are effective factors capable of changing the position of ranges. Thus, in a system connected in a series of electrostatic and quantum capacitances, the resulting capacitance will significantly depend on the Cq behavior. Comparative analyses of structures, chemical bonds, majority of coinciding characteristics of physical quantities in graphite, transition metal dichalcogenides (TMD), and layered crystals A3B6 allow us to assert that the obtained qualitative conclusions can be applied for each of them. Calculations of density of states (DOS) of quasi-2D crystals performed by authors within the framework of the improved Kohn–Sham density functional theory (DFT), namely the DFT taking into account the van der Waals forces in it, show a step-like form of DOS qualitatively similar to ours.

Because of accelerated demands of advanced technologies like power station, chemical production and microelectronics, it necessitates the need of novel type of fluids with more heat transfer capability. Due to synergistic effect, ternary composite nanofluids (TCNFs) ensure better thermophysical and Rheology properties thereby acting as better suitable heat transfer fluid in wire coating, metal spinning, aerodynamics, medicine and engineering industries, etc. In view of such relevance, flow and heat transfer aspects of TCNF MWCNT + Al2O3 + TiO2 + water induced by linear and nonlinear slips over arbitrarily inclined moving thin needle are investigated in this study. Thompson and Troian nonlinear slip model is modified by developing it in polar coordinates. Quadratic thermal radiation phenomenon is adopted. Fourth-order Runge–Kutta method is used to obtain requisite numerical solution. Major outcomes indicate that fluid velocity of TCNF whittles down with amplification of magnetic parameter due to the flow induced by either linear or nonlinear slips. Lower value of Reynolds number favoring linear slip leads to effective intensification of nondimensional temperature distributions. Surface viscous drag and heat transfer rate get ameliorated with growth in size of thin needle under the influence of both linear and nonlinear slips.

This research delves into the fascinating transmission characteristics of a system with variable mass, confined by a Coulomb-like potential. By utilizing an analytic approach to transmission probability, we were able to unveil the intriguing features that are observed experimentally in a specially designed two-dimensional lattice. This lattice was engineered to manipulate itinerant electrons through entanglement, resulting in variable masses as they traverse the lattice. To build our model system, we utilized the displacement operator approach to the position-dependent effective mass theory. This allowed us to investigate the effects of different configurations of leads, system geometries and lattice deformations on the transmission characteristics of the system. The resulting data showed that the model system was highly sensitive to these parameters, which led to various interesting features. First, we observed Andreev-like reflections, which occur when a particle is reflected as a hole, resulting in the transfer of both energy and charge. Another feature was reflectionless transmission, in which the transmission probability of a particle is close to unity, and almost no reflection occurs. We also observed complete localization of charge carriers, where the transmission probability is effectively zero, indicating that the charge carriers are completely confined within the lattice. Our findings demonstrate the remarkable versatility of the effective mass approach in the modeling of physical systems. By unraveling the intricate relationships between system parameters and transmission probability, we have gained new insights into the behavior of itinerant charge carriers in lattice structures. These insights may guide the design and development of novel electronic devices with enhanced performance and functionality.

Bound states in the continuum (BICs) are a special kind of resonant states that remain localized even though they coexist with a continuous spectrum of radiating waves. They have already emerged as an important design principle for creating systems with high-quality (Q) factor states to enhance light–matter interaction. Many approaches have been proposed to achieve BICs, but it is still of great challenge to design multiple BICs simultaneously, and especially working at terahertz (THz) frequencies. In this paper, we propose an all-dielectric metamaterial, consisting of four hollow cylinders in each unit cell. We show dual BICs exist in such a simple structure, and as breaking the symmetry via varying the inner radius of two diagonal cylinders, they will turn to quasi-BICs with high yet finite Q-factor. These quasi-BICs are manifested themselves as two new dips in the transmission spectrum, of which the resonance shapes can be well described by the Fano formula with a few fitting parameters. We find the evolution of their Q-factors still follows the simple linear relationship with respect to the inverse square of the asymmetry parameter. Based on the multipole decomposition method, two BICs are further investigated to show different multipole components for them. Interestingly, the higher frequency BIC is closely related to the excitation of toroidal dipole (TD), which will split into two TDs as breaking the symmetry. The proposed metamaterial provides an alternative platform to merge the physics of BICs, Fano, and TD, and to pave the way for potential device applications (since the states of extremely high-Q factor).

In the absence and presence of a circularly polarized monochromatic electromagnetic pulse, we have analyzed the electron–nucleon scattering process, where the nucleon is assumed to be spinless with a spherical shape. We have provided the theoretical calculation of the differential cross section (DCS) by using the Dirac–Volkov formalism. This research paper aims to provide two comparisons: We first compare the DCS in the absence of the laser field with its corresponding laser-assisted DCS. A second comparison is made between the electron–proton and electron–neutron scattering processes to study the effect of the laser on both processes. The results obtained about the effect of the laser field on the DCS and the electric form factor have been discussed for both scattering processes. We have found that the DCS is reduced when the laser field is applied for both processes. In addition, the form factor is also decreased by raising the incident electron energy in electron–proton scattering, but it increases in electron–neutron scattering. Moreover, the form factors for both scattering situations are unchanged by raising the laser field strength up to 108V/cm.

This study addressed the compressible flow of viscous fluid in an asymmetric channel under peristalsis. The difference in amplitudes and phase of traveling waves created the asymmetry of channel. Simultaneous effect of magnetic field is also incorporated. Fluid flows through a porous medium. The analytical treatment of the solution is carried out by considering upper wall amplitude as the small parameter. The expressions of flow rate and net axial velocity are constructed for the second-order approximation. Numerical integration is employed to calculate net flow rate. The role of sundry parameters is illustrated graphically. Trapping phenomenon is also taken into account by plotting streamlines against sundry parameters. The significant finding of this study is that flow rate and axial velocity enhance as fluid transitions from hydrodynamic to hydromagnetic. Enhancement in the compressibility parameter trims down the velocity and the flow rate as well. Also, asymmetry of the channel causes an enhancement in the flow rate. This model is the most prevailing version of compressible flow under peristalsis through an asymmetric channel. The findings of this study have worth mentioning yields, which can be applicable in numerous areas of fluid dynamics and aircraft industry.

An analytical formulation that calculates the thermodynamic properties of zirconium carbide and zirconium nitride has been produced using the n-dimensional Debye function. The results of the heat capacity and entropy calculated here for ZrM (M=N and C) were compared with the literature data, and are found to be in agreement. This agreement shows that the used method would be useful to calculate the thermophysical properties (heat capacity, entropy, etc.) of materials such as ZrC and ZrN.

The aim of this paper is to examine the combined effects of unsteadiness and thermal radiation on the flow of a mixture nanoliquid due to a shrinking disk. Investigation of flow near a stagnation-point naturally arises in several industrial sectors and is useful owing to its significance in thermal enhancement. The motion is persuaded by a radially stretched/shrinked exterior of the disk in adding to the flow near a stagnation point. As a result, this research examines the thermophysical belongings of the unsteady flow near a stagnation-point past a stretching/shrinking disk by using twin-kind nanoelements, viz. a mixture nanoliquid. Cu and Al2O3 nanoparticles have been considered in water to produce hybrid nanofluid. The numerous uses like electronic cooling system, heat exchangers and radiators are available. Using similarity transformations, self-similar equations have been obtained which are then solved numerically using MATHEMATICA software. Comparisons have been made with the available data in the literature and found a complete agreement for some special case of the problem. Double solutions subsist for equally stretched and shrinked disks, whereas a unique solution exists for the static disk. For flow past a stretching or a shrinking disk, a 27.79% of increase in warmth transport speed is noted for mixture nanofluid, contrasted to the nanoliquid. Hence, this study will be of interest to several scientists and engineers, owing its capability to augment the speed of heat transport in contrast to the regular nanofluids.

This work investigates a non-Newtonian MHD Carreau nanofluid over a stretched vertical cylinder of an incompressible boundary layer with mobile microorganisms. The flow exists in permeable media and follows the modified Darcy’s law. An unchanged normal magnetic strength to the walls saturates the system. Ohmic dissipation, heat source, modified chemical reaction with activation energy properties, heat, volumetric nanoparticles fraction as well as microorganism profiles are covered. Thermal conductivity and mass diffusivity are taken as functions of heat and nanoparticle concentration, correspondingly. The fundamental governing system of nonlinear partial differential equations (PDEs) is converted into nonlinear ordinary differential equations (ODEs) by employing appropriate similarity transforms. The latter system is numerically analyzed through fourth-order Runge–Kutta (RK-4) simultaneously with the shooting process. The numerical outcomes showed that the curvature coefficient, magnetism and chemically activated energy perform a significant role in the velocity, heat, nanoparticle and chemical organism distributions. The impacts of several physical restrictions are tested and portrayed in a group of graphs. It is observed that the presence of microbes and nanoparticles, which are described in buoyancy terms, causes the flow to decay and slow down. By lowering the buoyancy and bio-convection characteristics, this infection can be prevented. With the development of all heat-related elements, heat transfer is enhanced, which is a significant feature associated with the current flow. These insights are important and useful in various physical and engineering fields.

This paper presents an accurate prediction of surface drag, pressure coefficient and flow transition around a symmetric airfoil design through the implementation of finite element discretization. Skin friction coefficient has been analyzed at different Reynolds number and at various angles of attack for NACA0012 airfoil design. The transition from laminar to turbulent flow significantly impacts the separation of the boundary layer and skin friction of the airfoil, ultimately affecting its aerodynamic characteristics. The pressure distribution around the surface of NACA0012 has also been computed at several Reynolds number and different attack angles using higher order triangular meshes. Numerical evaluation of these results when compared with the experimental results demonstrates superior accuracy with higher-order finite element mesh. The investigation carried out by higher-order element meshing approach is based on the subparametric transformation of parabolic arcs of triangular element curved at one side. Moreover, the high aspect ratio meshes obtained during discretization of airfoil design have been considered for the analysis. The investigation has yielded results that closely align with experimental data, demonstrating excellent performance. The current efficient analysis of pressure and flow transition is beneficial in interpreting aerodynamic performance and flow simulations for aerospace and computational fluid dynamics applications.