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This study describes thermal transmission features across a gravity-driven bioconvection flow of the viscoplastic-type Casson nanofluid caused by a vertically rotating cylinder under gyrotactic microorganisms. The research further quantifies the impact of nonlinear thermal radiations, heat source/sink and convective interface on the temperature and heat transmission rate of a nanofluid rotating on a cylindrical surface. The Buongiorno two-phase model characterizing Brownian diffusion and thermophoretic properties is utilized to examine the nanoparticle's effect on the Casson nanofluid. A system of strongly nonlinear PDEs is converted into a system of ODEs by using the appropriate variables. The MATLAB technique is used to build a numerical solution for nonlinear flow equations. The influences of various parameters on the volumetric concentration of nanoparticles, velocities, thermal fields, and microorganism profiles are examined. The finding indicates that an upsurge in the bioconvection Lewis parameter causes declines in the microorganism profile. The thermal and solutal distribution of species increases with an increase in thermophoresis parameter estimations. Significant thermal transport is acquired with greater radiation impacts. The microorganism's distribution is improved with a larger Peclet number. [ABSTRACT FROM AUTHOR]

In many engineering systems, hybrid and nanofluids are influenced by their respective thermophysical characteristics. Lately, several models have been envisaged to foresee the hybrid and nanofluid attributes. The properties of hybrid nanofluids (HNFs) as potential heat transfer fluids are controlled by numerous aspects such as solid part size, volume fraction, and temperature. Considering the interesting facts of the hybrid and nanofluid flows, we in this exploration examined the thermal performance comparison of both types of fluid flows. The nanofluid and HNF are composed of molybdenum disulfide (MoS2)/kerosene oil and silicon dioxide–molybdenum disulfide (SiO2–MoS2)/kerosene oil, respectively. The flows are taken in a canonical gap between the cone and the disk. Both the cone and the disk may be rotating or stationary. The novelty of the computational model is enhanced by discussing the effects of viscous dissipation, Joule heating, and the variable thermal conductivity with convective condition. The Tawari and Das model is designed to analyze the heat transfer performance of the assumed fluid flows. The assumed fluid model is transmuted into the set of differential equations that are dealt numerically with the bvp4c MATLAB approach. The results are displayed in tables and graphical forms. For elevating estimations of the Eckert number, the heat transmission rate is found to be more significant in the disk than cone. It is also learned that hybrid nanoliquid heat transfer performance outperforms nanoliquid. The fluid velocity increases by raising the nanoparticle volume fraction ϕmol, and is decreasing for a higher magnetic field parameter. With the elevating estimates of thermal conductivity, it is shown that the cone transmits heat more quickly whereas the disc transmits heat more slowly. The thermal conductivity parameter increases the probability of collision of the liquid particles, that ultimately upsurges fluid heat transmission rate. [ABSTRACT FROM AUTHOR]

AbstractIn models of fluid dynamics, the magnetic field is essential for preserving the stability of flow streams and found applications in magnetic resonance imaging, magnetic levitation, and geophysical exploration. Recognizing the significance of this magnetic influence, we aim to investigate the behavior of flow within a three-dimensional squeezed film of Casson fluid situated between two rotating disks, under the influence of an induced magnetic field and the Reynolds viscosity model. The study also meticulously examines the heat and mass transfers, taking into account the effects of thermo-diffusion and diffusion-thermo. The resulting torque on both the upper and lower surfaces is analyzed and presented in a tabulated format. The normalized system of equations is transformed into a set of first-order differential equations, which are then solved using the bvp4c numerical solver in MATLAB. The impacts of various parameters are graphically illustrated in two different scenarios (ϒ=0.0,0.5), i.e., constant and variable viscosity. It is observed that when the variable viscosity parameter is set to zero, the azimuthal velocity profile experiences a more pronounced increase as the rotational parameter rises. Conversely, the azimuthal magnetic profile exhibits a more significant decrease when considering the influence of the variable viscosity parameter. Finally, the results are compared with previous studies in the literature for a limiting case, and error is reduced between 0.000003% and 0.000002%. [ABSTRACT FROM AUTHOR]

This research captures nonlinear thermo-solutal buoyancy (i.e., nonlinear mixed convection) impact in nanofluid flow based on magnetized Casson model. The generalized porosity concept (i.e., Darcy–Forchheimer relationship) is employed by considering incompressible liquid that saturates the porous space. Effects of thermophoresis, Robin conditions, thermo-solutal stratifications and Brownian diffusion are accounted. Consideration of transpiration phenomenon captures suction/injection aspects. Fluid mechanics basic laws are depleted to simplify the governing rheological expressions. A transformation procedure is then employed to convert the nonlinear governing partial systems into differential systems. Homotopy methodology is used to obtain analytical solutions and convergence is ensured. Graphical and tabular outcomes are presented to address the importance of emerging variables. [ABSTRACT FROM AUTHOR]

AbstractThe intension of recent analysis is to discuss the radiated magnetized flow of Maxwell nanoliquid. Flow is induced due to stretching the surface. Convective and zero mass flux conditions are taken into account. Influence of Soret and Dufour are under consideration. Internal heat source, magnetic field and thermal radiation are discussed in energy expression. Random diffusion and thermophoresis characteristics in presence of chemical reaction are deliberated. Thermal conductivity and viscosity depend upon temperature. Similarity transformation is utilized to transform nonlinear partial differential systems into ordinary systems. ND-solve technique is used to get the numerical solutions for nonlinear nondimensional system. Graphical analysis for flow, concentration and thermal distribution versus emerging variables are examined. Computational outcomes for solutal transport rate and Nusselt number via sundry variables are explored. Velocity profile declines against magnetic field, whereas reverse trend found for temperature profile. Thermal field has increasing trend for thermal Biot and Dufour numbers. Larger Maxwell variable has opposite effect on flow field. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR) sensing methods enable highly sensitive, fast response, and label-free analysis of biomolecular interactions. For SPR sensors, sensitivity and full width at half maximum (FWHM) are two incompatible performance parameters. We propose a refractive index (RI) sensor using a dual-core photonic crystal fiber (PCF) and SPR effects to achieve high sensitivity and a narrow FWHM simultaneously. The air holes of the sensor appear in a hexagonal arrangement, and polishing technology introduces two polishing planes into the cladding. A gold film is deposited on one side of the polished plane to form a highly sensitive RI sensing channel. Five gold nanowires are deposited on the other side of the polished plane to form a RI sensing channel with a narrow FWHM. We analyzed and optimized its structural parameters using the finite element method and determined the optimal structural parameters. The numerical results demonstrate that the maximum sensitivity of the sensor is 21,000 nm/RIU with the narrowest FWHM of 31 nm. Therefore, measuring the refractive index simultaneously with two sensing channels increases the detection accuracy of the measurement. In addition, the findings further indicate that variations in structural parameters do not significantly impact the sensing performance of the sensor, which makes the production of the sensor relatively simple. In conclusion, our work provides a new research method for realizing high sensitivity and a narrow FWHM simultaneously. [ABSTRACT FROM AUTHOR]

The peristaltic mechanism of a non‐Newtonian Ree‐Eyring liquid in the presence of variable liquid properties and heat transfer is an integral component of technology and healthcare systems. This study aims to investigate and analyze this mechanism, taking into account the influence of wall properties and variable liquid properties. The long wavelength and Low Reynolds approximations are used in the model designed for this purpose. A regular perturbation technique solves the resulting nonlinear partial differential equations with the proper non‐dimensional parameters. The magnetic field's influence is crucial in determining the fluid flow behavior, whereas the variable liquid properties significantly affect the temperature profiles. This research contributes to an improved understanding of peristalsis in the context of Ree‐Eyring liquids and has potential implications for several technical and medical applications. [ABSTRACT FROM AUTHOR]

AbstractA theoretical study is carried out to explore the heat and mass transfer features in the flow of two types nanofluid, i.e., Al2O3/H2O micropolar nanofluid and (Al2O3+Ag)/H2O hybrid nanofluid, adjacent to a solid sphere. Furthermore, simultaneous effects of linear thermal radiation and chemical reaction are also explored on the heat and mass transfer characteristics. In mathematical formulation basic conservation laws are utilized along with the Soret and Doufer effects as a coupling agents in the energy and mass concentration equations. The normalized variables are used to transform the governing system of non-linear partial differential equations into the system of dimensionless partial differential equations. Stream function reduces the number of dependent variables and the resulting system is solved numerically by Keller box method. Several plots are presented to explore the impact of involved parameters on the different profiles and engineering interest quantities for both types of fluids. The temperature profile and Nusselt number are large in magnitude for hybrid nanofluid as compared to Al2O3/water based nanofluid. The heat transfer and mass transfer rates rises with thermal radiation parameter and chemical reaction parameter, respectively. [ABSTRACT FROM AUTHOR]

The phenomenon of heat as well as mass transfer due to ferromagnetic flow of Oldroyd‐B nanofluid is addressed. The additional thermal source like heat source, thermal radiation, and activation energy features has been implemented to extend the dynamic of flow problem. The source of flow is moving stretching surface with magnetic dipole impact. The convective boundary conditions are implemented. The Boungrino nanofluid model is used to observe the thermophoresis and Brownian motion consequences. The mathematical modeling of problem in view of flow assumptions will be converted into the non‐dimensional form. The numerical shooting technique will be implemented for presenting the approximate simulations. After verifying the solution accuracy, the physical dynamic of problem with variation of parameter is presented. It is noticed that the velocity profile reduces due to ferrohydrodynamic interaction parameter. An enhanced thermal profile is observed due to relaxation time constant and ferrohydrodynamic interaction parameter. Furthermore, the concentration profile reduces for retardation time constant parameter. [ABSTRACT FROM AUTHOR]

Lie similarity transformations for unsteady flow in a thin film under the influence of internal heating and thermal radiation have been deduced earlier. These transformations have been employed to reduce the partial differential equations of the fluid flow and heat transfer to ordinary differential equations. Fluid velocity and temperature profiles were presented by constructing homotopic solutions for the obtained system of equations. Here we apply a general linear combination of all the Lie point symmetries associated with the equations describing the flow and heat transfer with internal heating and thermal radiation, to construct the general Lie similarity transformations. By applying these transformations to the flow, we map them to ordinary differential equations. The reduced system of differential equations contains the arbitrary constants used to construct the generalised Lie similarity transformations through the linear combination of all the Lie symmetries of the flow equations. Further, we determine analytic solutions using the homotopy analysis method for the reduced system of equations. We show that the presence of arbitrary constants in the reduced system of differential equations enables control of the deduced homotopic analytic solutions, i.e., these constants serve as control parameters. We illustrate the effects of these control parameters on the temperature profiles graphically. [ABSTRACT FROM AUTHOR]

The heat transfer phenomenon in the flow of non-Newtonian fluids is important in the manufacturing processes of plastic products, cooling systems polymer solutions and extrusion and injection phenomena, etc. The motivation behind this study is to explore the thermal aspects of Burger non-Newtonian fluids by applying exponential heat source–sink, mixed convection phenomenon and thermal radiation. The analysis was done for different values of fluid viscosity. The numerical methodology is based on the implementation of a variational iteration technique. It is concluded that consideration of variable fluid viscosity is important to improve the heat transfer phenomenon more precisely. It is seen that the temperature profile increases with exponential heat source parameters. [ABSTRACT FROM AUTHOR]

In a wide variety of mechanical and industrial applications, e.g., space cooling, nuclear reactor cooling, medicinal utilizations (magnetic drug targeting), energy generation, and heat conduction in tissues, the heat transfer phenomenon is involved. Fourier's law of heat conduction has been used as the foundation for predicting the heat transfer behavior in a variety of real-world contexts. This model's production of a parabolic energy expression, which means that an initial disturbance would immediately affect the system under investigation, is one of its main drawbacks. Therefore, numerous researchers worked on such problem to resolve this issue. At last, this problem was resolved by Cattaneo by adding relaxation time for heat flux in Fourier's law, which was defined as the time required to establish steady heat conduction once a temperature gradient is imposed. Christov offered a material invariant version of Cattaneo's model by taking into account the upper-connected derivative of the Oldroyd model. Nowadays, both models are combinedly known as the Cattaneo-Christov (CC) model. In this attempt, the mixed convective MHD Falkner-Skan Sutterby nanofluid flow is addressed towards a wedge surface in the presence of the variable external magnetic field. The CC model is incorporated instead of Fourier's law for the examination of heat transfer features in the energy expression. A two-phase nanofluid model is utilized for the implementation of nano-concept. The nonlinear system of equations is tackled through the bvp4c technique in the MATLAB software 2016. The influence of pertinent flow parameters is discussed and displayed through different sketches. Major and important results are summarized in the conclusion section. Furthermore, in both cases of wall-through flow (i.e., suction and injection effects), the porosity parameters increase the flow speed, and decrease the heat transport and the influence of drag forces. [ABSTRACT FROM AUTHOR]

In this work, a novel compact difference scheme for the generalized Rosenau-KdV-RLW equation is investigated, which preserves some conservative properties of the original equation. The proposed numerical scheme is three-level and nonlinear implicit, which adopts a novel approximation 1 4 (U j n + 1 + 2 U j n + U j n - 1) of u (x j , t n) in the temporal direction and a direct compact discretization method for the higher-order derivatives u xxx and u xxxx in the spatial direction. The discrete conservation laws are given, and a priori estimates of the difference solution in maximum norm are obtained by applying mathematical induction. The solvability of the proposed numerical scheme is proved by the well-known Brouwer's fixed point theorem. The convergence with O (τ 2 + h 4) convergence order and stability of the novel difference scheme in L ∞ norm are proved. A linearized iterative algorithm for solving nonlinear algebraic systems generated by the compact scheme is proposed and its convergence is proved. Some numerical experimental results validate the theoretical results and demonstrate that the proposed compact scheme is efficient and reliable. [ABSTRACT FROM AUTHOR]

This paper presents a mathematical model in the biofilm phase and in the gas phase that has been successfully applied to investigate various aspects of the biofiltration process. The mixtures of volatile organic compounds (VOCs) are emitted from a wide range of industries, such as chemical, petrochemical, pharmaceutical, pulp paper mills, printing and paint workshops, etc. The objective of the present study is, presence of high n-propanol loading negatively affected the toluene removal; however, n-propanol removal was not affected by the presence of toluene and was effectively removed in the biofilter despite high toluene loadings. A model for toluene and n-propanol biofiltration could predict the cross-inhibition effect of n-propanol on toluene removal. Further, we studied the effects of many physical and biological parameters on model prediction. The mathematical equations (2.12)-(2.16) which are non-linear partial differential equations are solved by using the homotopy perturbation technique. Also, we derived the semi-analytical results for toluene and n -propanol concentrations for saturated and unsaturated kinetics. It is verified that the proposed solution is validated by comparing it with numerical solutions. • Here mathematical modelling is developed for bio-filtration in the biofilm phase. • The adopted model investigate various aspects of the bio-filtration process. • Analytical results is obtained via Homotopy Perturbation Technique. • The obtained solutions is verified for accuracy with existing literature. [ABSTRACT FROM AUTHOR]

Depth estimation is an important part of the perception system in autonomous driving. Current studies often reconstruct dense depth maps from RGB images and sparse depth maps obtained from other sensors. However, existing methods often pay insufficient attention to latent semantic information. Considering the highly structured characteristics of driving scenes, we propose a dual-branch network to predict dense depth maps by fusing radar and RGB images. The driving scene is divided into three parts in the proposed architecture, each predicting a depth map, which is finally merged into one by implementing the fusion strategy in order to make full use of the potential semantic information in the driving scene. In addition, a variant L1 loss function is applied in the training phase, directing the network to focus more on those areas of interest when driving. Our proposed method is evaluated on the nuScenes dataset. Experiments demonstrate its effectiveness in comparison with previous state of the art methods. [ABSTRACT FROM AUTHOR]

Abstract There is a awakening interest in applying bioconvective nanofluids in permeable media. As such, this article aims to numerically investigate boundary layer flow over a plate embedded in a porous medium filled with nanofluid with motile gyrotactic microorganisms. Consequence, mass and heat transmission efficiency in engineering, technological, and industrial domains is improved. Thus, heat and mass transmission with impacts of radiation and activation energy on the horizontal porous plate are analyzed with microorganisms. Ordinary differential equations are established from nonlinear leading Partial Differential Equations by implementing similarity variables. After that, the resultant ordinary differential equations are numerically tackled employing the BVP4C method, build-in package of MATLAB. From tables, it is evident that when the velocity parameter is one, skin friction is zero, which exhibits no opposition at the fluid-solid surface. The impacts of pertinent parameters upon nondimensional boundary layer outlines are deliberated. It is worth mentioning here that the impact of the magnetic field parameter ( 1 ≤ M ≤ 3 ) on velocity is drawn, and the graph depicts that the velocity is diminished by increasing the value of the magnetic parameter. It is because when the magnetic field is given perpendicular to the liquid’s surface, the generated magnetic impact causes the liquid to flow with a resistive form of force, which reduces its speed for the solutal resistance is increased by activation energy ( 1 ≤ E ≤ 3 ) but decreased by Lewis number ( 1 ≤ L e ≤ 3 ) , and chemical reaction constant ( 1 ≤ σ ≤ 3 ) . Finally, current inquiry can helpfully enhance thermal conductivity, viscosity, convective heat transmission, and thermal diffusivity linked to those base fluids. The current investigation reveals that the Lewis number and chemical reaction constant tend to decay thickness of concentration boundary layer. [ABSTRACT FROM AUTHOR]

In this paper, a new three-level implicit and fourth-order compact conservative difference scheme is developed for the generalized symmetric regularized long wave equations. The proposed scheme adopts a new time discretization method. The conservation of the new compact scheme is proved, and the discrete conservation laws are obtained. The priori estimation in the maximum norm is discussed by the discrete energy method and mathematical induction. Based on the priori estimation and Brouwer's fixed point theorem, the unique existence of the difference solution is proved. It is proved that the compact difference scheme is unconditionally convergent and stable in the maximum norm, and its convergence order is the fourth order in space and the second order in time. A decoupled and linearized iterative algorithm is proposed to calculate the nonlinear algebraic system generated by the compact scheme, and its convergence is proved. Several numerical experiments are performed to prove the efficiency and reliability of the proposed numerical scheme and to confirm the results obtained from the theoretical analysis. [ABSTRACT FROM AUTHOR]

The impact of chemical reaction and activation energy plays a vital role in the analysis of fluid dynamics and its thermal properties. The application of the flow of fluid is significantly considered in nuclear reactors, automobiles, manufacturing setups, electronic appliances etc. This study explores the impacts of activation energy and chemical reaction on the magnetohydrodynamic Darcy–Forchheimer squeezed Casson fluid flow through a porous material across the horizontal channel where the two parallel plates are assumed to be in motion. By using similarity variables, partial differential equations are converted to ordinary differential equations. Numerical method is applied using MATLAB to solve the problems and acquire the data for velocity field, thermal distribution, and concentration distribution. The graphs indicate that fluid velocity and temperature increases as the plates are brought closer. In addition, there was a correlation between a rise in the Hartmann number and a decrease in the fluid's velocity because of the existence of strong Lorentz forces. The temperature and the concentration of the liquid will increase due to the Brownian motion. When the Darcy–Forchheimer and activation energy parameters are both increased, the velocity and concentration decreases. [ABSTRACT FROM AUTHOR]

In this article, the flow of ternary nanofluid is analysed past a stretching sheet subjected to Thomson and Troian slip condition along with the temperature jump. The ternary nanofluid is formed by suspending three different types of nanoparticles namely TiO 2 , Cu and Ag into water which acts as a base fluid and leads to the motion of nanoparticles. The high thermal conductivity and chemical stability of silver was the main cause for its suspension as the third nanoparticle into the hybrid nanofluid Cu-TiO 2 / H 2 O . Thus, forming the ternary nanofluid Ag-Cu-TiO 2 / H 2 O . The sheet is assumed to be vertically stretching where the gravitational force will have its impact in the form of free convection. Furthermore, the presence of radiation and heat source/sink is assumed so that the energy equation thus formed will be similar to most of the real life applications. The assumption mentioned here leads to the mathematical model framed using partial differential equations (PDE) which are further transformed to ordinary differential equations (ODE) using suitable similarity transformations. Thus, obtained system of equations is solved by incorporating the RKF-45 numerical technique. The results indicated that the increase in the suspension of silver nanoparticles enhanced the temperature and due to density, the velocity of the flow is reduced. The slip in the velocity decreased the flow speed while the temperature of the nanofluid was observed to be increasing. [ABSTRACT FROM AUTHOR]

In this paper, a new fourth-order compact finite difference scheme is proposed to solve the extended Fisher-Kolmogorov (EFK) equation. The scheme is three-level and implicit nonlinear. A new time discretization technique is adopted in the new scheme. The priori estimate and convergence of the numerical solution are obtained by using the discrete energy method, and the optimal error estimation in the maximum norm shows that the proposed numerical scheme has second-order accuracy in time and fourth-order accuracy in space. Finally, the theoretical analysis is supported by the numerical results of several examples. [ABSTRACT FROM AUTHOR]

• New FWM design to compensate for the uncertainty caused by continuous and disruptive time delays. • Adapting the FWM method to the LMI in the form of an optimization problem. • Combined modeling of energy storage system with RES in large-scale power system. • Using state observer with FWM for better observability of closed-loop system poles in the design process. Due to the high penetration of renewable energy sources (RES) such as wind units in power systems, the need to check the stability of transmission networks has been given more attention than before. Therefore, in this paper, due to the importance of the topic, the wide area damping controller (WADC) has been used for the battery energy storage system (BESS) connected to the photovoltaic unit and the permanent magnet synchronous generator (PMSG) in the dc link. The WADC design is based on free weight matrices (FWM), which can solve a set of constraints based on the linear matrix inequality (LMI) based on the delay-dependent feedback control theory. The working method is that the constraints related to LMI are considered in such a way that it has the ability to tolerate the maximum amount of time delay. FWM has been used to communicate between LMI constraints and the maximum value of the time delay margin. FWM matrices are also based on an iterative algorithm based on linearization of the conical complement, which tries to search for the most optimal value for the control parameters. To implement the simulation results in MATLAB software, an improved power system of 16 machines has been used, the results of which are clearly analyzed and show the superiority of the proposed method compared to other mentioned methods. [ABSTRACT FROM AUTHOR]

Photonic crystal fibers (PCFs) have brought tremendous advancements due to their predominant feature of a peculiar air-hole arrangement in the 2D direction. Functional materials like metals, magnetic fluids, nematic liquid crystals, graphene and so on, are being extensively adopted for integration with PCFs to obtain extraordinary transmission properties. This review takes the development stages of photonic devices based on functional material-infiltrated PCFs into consideration, covering the overview of common materials and their photoelectric characteristics, state-of-art infiltrating/coating techniques, and the corresponding applications involving polarization filtering and splitting devices in optical communication and sensing elements related to multiple-parameter measurement. The cladding airhole of PCFs provides a natural optofluidic channel for materials to be introduced, lightâ€"matter interaction to beenhanced, and transmission properties to be extended, in this case, a lab on a fiber are able to be implemented. This paves the way for the development of photonic devices in the aspects of compact, multi-functional integration as well as electromagnetic resistance. When the PCFs are integrated with the phemomenon of surface plasmon resonance, the property of tunable refractive indices, and the flexible geometry structures, it comes up to some representative researches on polarization filters, multiplexer-demultiplexers, splitters, couplers and sensors. It makes a candidate for widespread fields of telecommunication, signal-capacity, and high-performance sensing. [ABSTRACT FROM AUTHOR]

Novel materials with high thermal conductivity are urgently needed to solve the problem of thermal diffusion with the rapid development of science and technology. Experiments have been conducted to join polydopamine (PDA) with graphene (G) and carbon fibers (CF) using electrophoresis to form a G/PDA@CF material with ultrahigh thermal conductivity. The thermal conductivity has been improved by a factor of 6, which has ultrahigh thermally conductive properties. The composite doubled the tensile strength relative to the original material. Experiments were designed to test the thermal conductivity of G/PDA@CF. Scanning electron microscopy (SEM), X-ray diffraction pattern (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) analyses of the material were carried out to obtain the formation mechanism of G/PDA@CF. The SEM image shows that PDA and G formed a layered self-assembled structure on the CF surface. The XRD image shows the existence of G in G/PDA@CF. The XPS analysis obtained the bonding species between the G and PDA, CF and PDA. The phonon spectra were then calculated by microcanonical ensembles (NVE). The PDA has ultrahigh thermal conductivity due to the high overlap of its phonon spectrum with G, which leads to its high strength thermal conductivity of G/PDA@CF. G/PDA@CF material can be used for flexible screens, housings for wearable devices, and thermally conductive devices. [ABSTRACT FROM AUTHOR]

The application of regression machine learning techniques is crucial for the analysis and optimization of energy systems based on geothermal energy to produce freshwater, power, and heating. This study applied regression machine learning techniques to investigate and optimize a geothermal tri-generation energy system that combines double-flash geothermal energy, humidification-dehumidification desalination, and transcritical carbon dioxide Rankine cycle. The goal was to produce freshwater, power, and heating. The algorithms performed remarkably well, with R-squared values surpassing 96 %. It is worth mentioning that for specific parameters like freshwater production, heating capacity, and efficiency, the R-squared values exceeded an impressive 99 %. The optimum conditions include maintaining a Rankine pressure ratio of 3, a mass flow rate of 30 kg/s, a geothermal temperature of 220 °C, and a turbine pressure ratio of 2.2. By following these ideal parameters, it is possible to achieve the highest level of system performance. This will lead to the production of 7.88 kg/s of freshwater, the generation of 1283 kW of power, a heating capacity of 30.8 kg/s, and an impressive system efficiency of 24.98 %. The findings reveal that the integration of regression machine learning algorithms in geothermal energy systems for freshwater, power, and heating production holds great promise for a sustainable and efficient future. • Regression machine learning techniques were applied on a geothermal-based system. • The goal was to produce freshwater, power, and heating. • The algorithms performed remarkably well, with R-squared values surpassing 96 %. • 7.9 kg/s of freshwater, 1283 kW of power, and 30.8 kg/s of heating were achieved. • Optimized integrated system efficiency was 24.98 %. [ABSTRACT FROM AUTHOR]

Thermal and flow features of nanofluid are explored under the impact of an external magnetic field whereas fluid is flowing inside a vertical square duct. It is assumed that the sunlight tends to heat up the duct. Two fins are attached to the duct that receive sunlight of uniform intensity. Two walls of the duct contain a fixed temperature and, are exposed to the direct sunlight under the assumption of a particular thermal boundary condition and developed flow. The governing equations of the problem are solved by the finite volume method. The taller fins not only act as significant obstacles causing reduction in flow velocity and frictional losses but also contribute to enhanced the rate of heat transfer more extensively with the surfaces of fins. Higher Rayleigh number fosters buoyancy-driven natural convection, causing a change in the thermal signature and diminution in thermal distribution over the domain. The magnetic force also tends to impede thermal diffusion, thus hampering heat transfer within the flow. The pressure gradient and the nanoparticle volume fraction significantly reduce fRe. On the other hand, the fin height, Rayleigh number and the magnetic parameter cause an enhancement in the Nusselt number and fRe. Finally, introducing a modern perspective into the research approach, machine learning technique (Neural Fitting app) was incorporated to refine the analysis. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present a thorough investigation into the impact of an external magnetic field on the flow and thermal properties of nanofluid within a vertically oriented square duct exposed to sunlight-induced heating. The duct incorporates two rectangular fins attached to one set of adjacent walls, receiving uniform sunlight intensity. In contrast, the other two walls feature a thin lubricant film which causes the fluid slip rather than adhesion. Assuming hydrodynamically and thermally developed laminar flow, the study employs a specific thermal boundary condition, enforcing a constant heat flux per unit axial length and a uniform peripheral temperature at the sun-exposed duct walls. Considering the balance between computational efficiency and solution accuracy, the finite volume method is employed to solve the governing partial differential equations. It has been observed that the magnetic parameter induces magnetic damping, resulting in a reduction in velocity distribution and qualitative alterations in flow patterns within the duct due to the heightened impact of the applied magnetic field. The presence of taller fins acts as significant obstacles which divert the flow and cause additional frictional losses, resulting in an overall reduction in flow speed. Elevated Rayleigh numbers amplify natural convection currents, producing a more pronounced change in velocity distribution while qualitatively transforming the thermal signature within the duct. Further, the slip parameter increases the overall velocity distribution while exerting a minimal impact on the thermal distribution, due to a reduction in resistance along the walls with lubrication, facilitating smoother fluid motion and leading to a more widespread velocity profile throughout the duct. Finally, to bring a contemporary perspective to the research methodology, modern techniques such as machine learning were integrated. The widely adopted Neural Fitting app was employed to enhance the precision of the analysis. [ABSTRACT FROM AUTHOR]

A high‐sensitivity square‐lattice photonic crystal fiber (PCF) refractive index (RI) sensor based on an external gold coating is proposed. This design eliminates the limitations of selective coating and liquid penetration in the micrometer holes, and avoids the side polishing of D‐type fibers. The effects of air hole diameter and gold film thickness on the sensing performance are studied in detail using the full vector finite element method (FV‐FEM). In addition, the sensing performance of the gold‐coated PCF under the optimized parameters is compared with that of PCF with the same air hole diameter and a gold grating. The results show that the proposed PCF has a higher structural tolerance to the air hole diameter, which improves the manufacturing feasibility. Moreover, the gold‐coated PCF has a maximum sensitivity of 31 000 nm RIU−1 and a resolution of 3.23 × 10−6 RIU in the RI measurement range of 1.34–1.49. The maximum sensitivity of the gold‐grating PCF with lower loss is 30 000 nm RIU−1 in the RI detection range of 1.38–1.46, and the resolution is 3.33 × 10−6 RIU. Low loss is beneficial for extending the length of the fiber, which is convenient for practical implementation. Thus, it has potential applications in biomolecular and biochemical analysis. [ABSTRACT FROM AUTHOR]

N6‐methyladenosine (m6A) methylation modification affects the tumorigenesis and metastasis of breast cancer (BC). This study investigated the association between m6A regulator‐mediated methylation modification patterns and characterization of the tumour microenvironment in BC, as well as their prognostic importance. Public gene expression data and clinical annotations were collected from The Cancer Genome Atlas (TCGA) database, the Gene Expression Omnibus website and the METABRIC program. We analysed the genetic expression, gene–gene interactions, gene mutations and copy number variations using R software. The data were screened for risk genes using the Cox risk regression model, and we developed an algorithm for risk score and its predictive value. Compared to adjacent normal tissue, we identified 16 differentially expressed m6A regulators in BC, including six writers and 10 readers. Under unsupervised clustering, two distinguished modification patterns were identified, cluster C1 and C2. Compared to m6A cluster C2, cluster C1 was found to be more involved in immune‐related pathways, with a relatively higher immune score and stromal score (P < 0.05). Patients were divided into two groups based on their risk scores for survival analysis. The patients in the high‐risk score group had significantly worse overall survival than patients in the low‐risk score group, (P < 0.0001). The TCGA database validation revealed the same prognostic tendency. In summary, our study showed distinct m6A regulator modification patterns contribute to the immunological heterogeneity and diversity of BC. The development of m6A gene signatures and the m6A score aid in the prognostic prediction of patients with BC. [ABSTRACT FROM AUTHOR]

This paper presents a dual-core two-parameter optical fiber sensor based on the surface plasmonic resonance (SPR) effect. It is analyzed by the finite element method. The proposed sensor is a dual-channel structure designed with photonic crystal fiber (PCF) as the base material: one channel is coated with a gold film to measure the refractive index (RI) of the solution to be measured, and the other channel is coated with a gold film and polydimethylsiloxane to measure the temperature of the solution to be measured. The exposed microslot structure on both sides reduces the complexity of sensing measurements. The results show that the maximum RI sensitivity of the sensor is 19,900 nm/RIU, and the maximum sensitivity to temperature is 8.7 nm/℃. This work is conducive to realizing a PCF sensor with high sensitivity, large measurement range, real-time monitoring, and easy preparation. As a result, the sensor is expected to be widely used in fields such as biology and chemicals. [ABSTRACT FROM AUTHOR]

Due to its unique technological characteristics, coal mining and production often encounter an acid corrosion environment caused by acid gases. Acid erosion and a series of chemical reactions caused by it often led to the deterioration of coal, rock, support structure, etc. and induced serious safety accidents. To further explore the macro-mesoscopic damage evolution law and failure mechanisms of rock masses under corrosion conditions through numerical simulation, a zonal refined numerical model that can reflect the acid corrosion characteristics of sandstone is established based on CT and digital image processing (DIP). The uniaxial compression test of corroded sandstone is simulated by ABAQUS software. Comparing the numerical simulation results with the physical experiment results, we found that the three-dimensional finite element model based on CT scanning technology can genuinely reflect sandstone's corrosion characteristic. The numerical simulation results of the stress-strain curve and macroscopic failure mode of the acid-corroded sandstone are in good agreement with the experimental results, which provides a useful method for further studying the damage evolution mechanism of the acid-corroded rock mass. Furthermore, the deformation and damage evolution law of the corroded sandstone under uniaxial compression is qualitatively analyzed based on the numerical simulation. The results show that the rock sample's axial displacement decreases gradually from top to bottom under the axial load, and the vertical variation is relatively uniform. In contrast, the rock sample's removal gradually increases with the increase of axial pressure, and the growth presents a certain degree of nonuniformity in the vertical. The acid-etched rock sample's damage starts from both the end and the middle; it first appears in the corroded area. Moreover, with the displacement load increase, it gradually develops and is merged in the middle of the rock sample and forms macroscopic damage. [ABSTRACT FROM AUTHOR]

Sulfur dioxide (SO2) belongs to the highly reactive group of gases familiar as “Oxides of Sulfur”. SO2 has lots of adverse effects on plants, respiratory system and many other environmental issues. Sulfur dioxide is a primary pollutant which is regulated worldwide, due to the combustion of fuel. Different approaches are adopted to economically control the SO2 in the environment which causes the production of sulfuric acid that is reflected in acid rain. The aim of this study is to investigate the invariant regions and solution pathways for the formation of H2SO4 in a multi-step reaction mechanism. The employed Model Reduction Techniques (MRTs) such as Spectral Quasi Equilibrium Manifold (SQEM) and Intrinsic Low Dimensional Manifold (ILDM) give the solution curves, which functions as a primary approximation to invariant manifold. It is achieved that each chemical specie can be assessed rather than taking the overall mechanism. The new discovery suggests that we could achieve the invariant regions for SO2 and H2SO4. SO2 emissions, along with emission norms, will be disclosed. The comparison of MRTs is depicted through tabular and graphical representations, while theoretical results are demonstrated through computer simulations using MATLAB. [ABSTRACT FROM AUTHOR]

• Eyring fluid flow across two deformable rotating disks is considered. • The fluid flow is affected by thermophoretic particle deposition and double diffusion. • Impacts of Hall current and ion slip are also assumed. • The model is supported by multiple slips at the boundary of the surface. • The problem is solved numerically. This work emphasizes the characteristics of thermophoretic particle deposition on Ree-Eyring fluid flow with Hall current and Ion slip effects between two deformable spinning disks. The novelty of the envisioned model is strengthened by considering generalized Fourier and Fick laws with thermal source/sink. The proposed model is optimized by taking multiple slip boundary constraints at the surface. The equations that govern the flow are simplified with the use of the proper transformations. The numerical solution is obtained using the boundary value problem of fourth order (bvp4c) method. Graphical representations of the emerging parameters are presented. Numerical values of skin friction coefficient, local Nusselt, and Stanton number are highlighted in tabular form. The velocity field depicts a deteriorating behavior on incrementing the Reynold number. For augmented values of Hall and ion slip parameters fluid velocity elevates. An upsurge is noticed in the axial and radial velocities on amplifying the rotation parameter. On augmenting the thermophoretic parameter the particle deposition at the interface of the upper disk diminishes. Growing values of rotation parameter, Weissenberg, and Reynold numbers imply an additional resistance to the fluid flow that ultimately reinforced the surface drag force causing a decline in the fluid velocity. The rate of heat transmission accelerates on enhancing the Reynold number, however, heat flux exhibits a decay on augmenting the thermal slip parameter. On augmenting the thermophoretic parameter particle deposition deteriorates at the interface of the upper disk. An excellent concordance is noticed when the outcomes are contrasted with the previous literature. For the value of the rotation parameter β = - 1 and β = - 8 the percentage error of the present analysis with Imtiaz et al. [68] are 0.00001 and 0.00002. [ABSTRACT FROM AUTHOR]

• Metal oxides with high RI will improve the sensing performance of fiber sensors. • Compared to silver-based sensors, the maximum sensitivity of TiO 2 composite film sensors has increased by 16.92 %. • Compared to silver-based sensors, the maximum sensitivity of ZnO composite film sensors has increased by 4.62 %. • The maximum temperature sensitivity of the two composite membrane sensors is 4.9 nm/℃ and 4.3 nm/℃, respectively. With the widespread application of fiber surface plasmon resonance (SPR) sensors in the field of biochemical sensing, especially in the detection of large molecules such as proteins, the sensitivity of traditional fiber SPR sensors has made it difficult to meet the requirements of detection accuracy in practical applications. This article proposes and proves an effective method for selecting the optimal metal oxide material to improve the sensing performance of SPR sensors. Metal oxides (TiO 2 and ZnO) can improve the sensitivity by enhancing the evanescent field of fiber SPR phenomenon. Through simulation, it was found that when the metal oxide film of the composite film sensor maintains the same thickness, the metal oxide with a high effective refractive index (RI) has a better improvement effect on the sensitivity of the SPR sensor. Experimental results show that the maximum RI sensitivity of TiO 2 composite film sensors and ZnO composite film sensors in the RI range of 1.333–1.420 is 15,200 nm/RIU and 13,600 nm/RIU, respectively. Compared to silver-based sensors, RI sensitivity has increased by 16.92 % and 4.62 %, respectively. To further verify the enhancement effect of different metal oxides on fiber sensors, another layer of PDMS film is deposited on TiO 2 and ZnO films. Within the temperature sensing range, the maximum temperature sensitivity of these two composite film temperature sensors is 4.9 nm/°C and 4.3 nm/°C, respectively. Overall, metal oxides with high RI can improve the sensing performance of fiber optic sensors. [ABSTRACT FROM AUTHOR]

Long-term exposure to chemical solutions can change the mineral composition and microstructure and may seriously affect the physical and mechanical properties of rocks. Therefore, to clarify the effects of long-term exposure and types of acids on the mechanical properties of rocks, and to develop the constitutive model of acid-immersed rocks, uniaxial compression tests were carried out on acid-immersed sandstone specimens. The sample weakened, and the brittle failure behavior became more ductile by the acid immersion to the aqueous solution of hydrochloric or sulfuric acids. The duration of the compaction stage of the stress–strain curve increased, that of the elastic stage decreased; the peak stress, elastic modulus, and Poisson's ratio decreased, and the peak point strains increased with the acidity and the immersion duration. The brittle shear failure of the untreated specimen became more axial splitting type failure with acidity. The damage variable of the combined effects of chemical and stress was introduced, and a statistical damage model considering the compaction stage of the stress–strain curve was established based on the damage variable. The model well-simulated the experimentally obtained stress–strain curves of the acid-immersed specimens. Finite element models reflecting the characteristics of the acid-immersed sandstone were established based on CT images. [ABSTRACT FROM AUTHOR]

The distribution of pedestrians in urban space reflects the status of urban spatial planning to some extent. The reasonable prediction of pedestrian concentration is of great significance to the evaluation of urban vitality, urban comfort, and urban spatial layout planning. In this paper, a method for predicting pedestrian concentration is proposed, which can estimate pedestrian concentration in a whole city without being limited to a specific intersection or city node. According to the characteristics of three kinds of transportation accessibility based on space syntax and commercial vitality index, a dynamic distribution estimation model of pedestrian concentration is proposed. Taking Xi'an city of China as a case study, through multiple linear regression (MLR), a support vector regression (SVR) algorithm, and random forest (RF) algorithm, the pedestrian concentration in five periods of a day was predicted and analyzed, and the spatial and temporal characteristics of crowd distribution are comprehensively described. The results show that the dynamic distribution model of pedestrian concentration constructed by RF is superior to the MLR and SVR, and its average prediction accuracy can reach 93.86%. [ABSTRACT FROM AUTHOR]

We consider the problem of scheduling jobs with sizes, release times and delivery times on identical parallel batch machines. All machines have the same capacity. Each machine can simultaneously process several jobs as a batch as long as the total size of these jobs does not exceed the capacity. The release time, processing time and delivery time of a batch are defined to be the latest release time, longest processing time and largest delivery time of all the jobs in the batch, respectively. The objective is to minimize the maximum delivery completion time, i.e., the time by which all jobs are delivered. For this strongly NP-hard problem, there does not exist any polynomial time algorithm with approximation ratio better than 2 unless P=NP, even if all jobs have equal processing times and all release times and delivery times are zero. We present an algorithm with approximation ratio arbitrarily close to 2. • Study parallel batch scheduling of minimizing maximum delivery completion time. • Jobs have non-identical sizes, release times and delivery times. • Present an algorithm with approximation ratio arbitrarily close to 2. [ABSTRACT FROM AUTHOR]

A biocompatible and robust fiber surface plasmon resonance (SPR) temperature sensor was fabricated based on an alcohol-filled hollow-core fiber. The fabrication process of this designed sensor included Ag film coating, liquid injection, and fusion splicing, which was low cost and efficient. Due to the high refractive index sensitivity of the SPR effect and the high thermal optical coefficient of alcohol, the designed sensor performed well in temperature sensing, whose linear sensitivity reached as high as 1.16 nm/°C in the range of 35.5 °C–70.1 °C. Being small in size, low in fabrication cost, and highly sensitive in performance, this sensor is suitable for temperature detection during biological and chemical reactions and has the potential to realizing multiparameter or distributed temperature measurement. [ABSTRACT FROM AUTHOR]

We propose a dynamic combined-mode traffic network model considering transfer behaviors. We assume that travelers can be classified into two classes: one class is pure-mode travelers who complete a trip by single transportation mode, and another is combined-mode travelers who cover a journey by car, bus, and so forth. The multimode point queue model is used to model the interaction of cars and buses on the network. We present an integrated variational inequality formulation to capture the complex traveler choice behaviors such as departure time choices, transfer point, and route choices. Finally, a numerical example is given to illustrate the effectiveness of the proposed heuristic algorithm and model. [ABSTRACT FROM AUTHOR]

We propose a dynamic combined-mode traffic network model considering transfer behaviors. We assume that travelers can be classified into two classes: one class is pure-mode travelers who complete a trip by single transportation mode, and another is combined-mode travelers who cover a journey by car, bus, and so forth. The multimode point queue model is used to model the interaction of cars and buses on the network. We present an integrated variational inequality formulation to capture the complex traveler choice behaviors such as departure time choices, transfer point, and route choices. Finally, a numerical example is given to illustrate the effectiveness of the proposed heuristic algorithm and model. [ABSTRACT FROM AUTHOR]

A novel curvature sensor was proposed based on a dual-core photonic crystal fiber (PCF) that was spliced between two single-mode fibers (SMFs). The sensor sensitivity was investigated both analytically and experimentally, and the influence of the PCF length and temperature on the sensor performance was also analyzed. The results showed the sensor had different sensitivity with different bending direction and its highest sensitivity can reach 10.14 nm/m−1. It also showed great insensitivity to temperature interference. Being of simple structure and good mechanical strength, this curvature sensor has great application potential in various fields, such as architecture, machinery, robot, wearable sensor, and so on. [ABSTRACT FROM AUTHOR]

Background: The Xpert MTB/RIF assay is an automated molecular test that is designed to simultaneously detect Mycobacterium tuberculosis (MTB) complex and rifampin resistance. However, there are relatively few studies on this method in China. Xpert has been routinely used at Peking University People's Hospital (PKUPH) since November 2016. Thus, the aim of this study was to evaluate the performance of Xpert, and provide a reference and guidance for the detection and diagnosis of TB in non-TB specialized hospitals.Methods: The medical records of inpatients simultaneously tested with Xpert, acid-fast bacilli (AFB) smear microscopy, and interferon-gamma release assay (IGRA, by T-SPOT®.TB) at PKUPH from November 2016 to October 2018 were reviewed. Active TB cases were considered according to a composite reference standard (CRS). Then, the three methods were evaluated and compared.Results: In total, 787 patients simultaneously tested with Xpert, AFB, and IGRA were enrolled; among them 11.3% (89/787) were diagnosed and confirmed active pulmonary TB (PTB, 52 cases), extrapulmonary TB (EPTB, 17 cases), and tuberculous pleurisy (TP, 20 cases). The sensitivity of Xpert in detecting PTB, EPTB, and TP was 88.5, 76.5, and 15.0%, respectively, which was slightly lower than IGRA (96.2, 82.4, and 95.0%, respectively), but higher than AFB (36.5, 11.8, and 0%, respectively); IGRA showed the highest sensitivity, but its specificity (55.9, 67.1, and 45.2%, respectively) was significantly lower than Xpert (99.6, 99.4, and 100%, respectively) and AFB (99.0, 99.4, and 100%, respectively) (P < 0.001). The sensitivity of Xpert in detecting lung tissue, cerebrospinal fluid, lymph nodes, and joint fluid was 100%, followed by sputum (88.5%), alveolar lavage (85.7%), and bronchoscopy secretion (81.2%); the pleural fluid sensitivity was the lowest, only 15.0%. For AFB negative patients, the sensitivity of Xpert in detecting PTB, EPTB, and TP was 84.9, 73.3, and 15.0%, respectively.Conclusions: Xpert showed both high sensitivity and high specificity, and suggested its high value in TB diagnosis; however, the application of pleural fluid is still limited, and should be improved. Owing to the high sensitivity of IGRA, it is recommended for use as a supplementary test, especially for assisting in the diagnosis of TP and EPTB. [ABSTRACT FROM AUTHOR]

A lattice sandwich structure mainly consisting of jute fiber and resin epoxy was prepared. Two configurations were established, and six out-of-plane compression experiments were conducted to identify the factors affecting the mechanical properties of the samples. The specific strength of the 2D corrugated lattice truss with the struts at 30° (I1) was 3 times stronger than that of the sample with sandwich struts at 45°. The specific strength of I1 was 3.9 times stronger than that of the Kagome structure prepared using Cu–2%Be. The cost performance with respect to the specific strength of the structure I1 was 161.7 times higher than that of the Kagome structure prepared using Cu–2%Be. Three failure modes were considered, and theoretical predictions were made separately. The failure modes in the experiment were mainly shear failure and shear buckling failure in sandwich struts. [ABSTRACT FROM AUTHOR]

A single-mode single-polarization photonic crystal fiber (SMSP-PCF) filter at the wavelengths of 1.125 and 1.31 μm based on surface plasmon resonance is proposed and studied by the finite element method. Numerical results indicate that compared with the filter with the same size of holes near the core, the filter with four small holes near the core makes its extinction ratio (ER) at the wavelengths of 1.125 and 1.31 μm twice as large. That is, when the fiber length is 500 μm, the ER at 1.125 μm increases from 33.43 to 58.62 dB, and the ER at 1.31 μm increases from 129.41 to 244.85 dB. Furthermore, the designed SMSP-PCF filter also has a good structural tolerance. The proposed optical fiber filter has excellent performance of compact structure, high ER and good structural tolerance, and can be used in an integrated communication transmission system. [ABSTRACT FROM AUTHOR]

The protein expression levels of Ring finger protein 2 (RNF2) and phosphor-protein kinase B (P-AKT) were determined in esophageal squamous cell carcinoma (ESCC) tissues, and the association between patient clinicopathological characteristics and survival time following definitive intensity-modulated radiotherapy was assessed. Cancerous biopsy tissues were collected from patients with ESCC at The Fourth Affiliated Hospital of Hebei Medical University between January 2010 and December 2013. Of these 99 cases, 83 were used to analyze the protein expression level of RNF2 (89.2% positive), 85 for P-AKT (65.9% positive) and 80 for RNF2+P-AKT protein expression levels (62.5% both positive). The expression levels of RNF2 protein in ESCC were associated with tumor volume (P=0.024), whilst those of P-AKT and RNF2+PAKT were associated with sex (P=0.041 and P=0.003, respectively). There were no significant differences in overall survival (OS) or progression-free survival (PFS) rate between the RNF2− and the RNF2+-+++ groups (P=0.134 and P=0.366, respectively), or between the P-AKT− group and P-AKT+-+++ group (P=0.468; P=0.580, respectively). The 1-, 3- and 5-year OS rates were 68.0, 28.0, and 20.0%, and 86.7, 53.3, and 31.1%, in the RNF2/P-AKT+ group and Other group, respectively (χ2=4.205; P=0.040). Multivariate analysis revealed that age, T stage and RNF2+P-AKT expression were independent prognostic factors for ESCC (P=0.010, P=0.008 and P=0.010, respectively). The expression of RNF2+P-AKT combined was an independent prognostic factor affecting survival rate, and therefore presents a potential prognostic indicator for patients with ESCC, treated with definitive radiotherapy. [ABSTRACT FROM AUTHOR]

Currently, bionic drag reduction is a popular research topic, particularly the drag reduction effect of a grooved structure. To investigate entropy generation caused by the effect of a grooved structure on flow, this study used Fluent software and large eddy simulation (LES) technology to analyze entropy generation in flow over a plate with a grooved structure. The purpose of this work is to provide a theoretical basis for reducing drag on such a structure. The study showed that a grooved structure was able to reduce entropy generation in the flow process. At 30 m/s, the total entropy generation in the near-wall region decreased by approximately 25%, and at 40 m/s, it decreased by approximately 19%. However, the grooved structure did not have a sustained effect on the subsequent flow. Moreover, as the distance from the wall in the normal direction increased, the effect gradually decreased. The secondary vortex that formed within the grooved structure changed the velocity gradient in the normal direction in the near-wall region and weakened the shearing action between flow layers, thereby reducing the entropy generation caused by viscous dissipation. Moreover, the reduction in entropy generation in the near-wall region was significant, decreasing by 49% and 58% at y+=5 when the flow rate was 30 and 40 m/s, respectively. Since the grooved structure was unable to inhibit the velocity fluctuations in turbulent flow, the magnitude of the entropy generation caused by the turbulence did not decrease. However, the distribution of the entropy generation caused by turbulent dissipation was more uniform in the region with the grooved structure than in the region with the smooth structure. The entropy generation at the tip of the grooved structure was one order of magnitude larger than the entropy generation at the near-wall region in the flow field. Even though the entropy generation caused by turbulent dissipation was predominant in that region, the entropy generation caused by viscous dissipation should not be ignored. [ABSTRACT FROM AUTHOR]

• Symmetrical polishing structure of dual-core photonic crystal fiber. • Gold layer is plated on the symmetrical side-polished surface of PCF to excite the surface plasmon polaritons. • The proposed sensor is able to detect the analyte the refractive indexes in the range of 1.3–1.42. • The maximum sensitivity of the proposed sensor is 8000 nm/RIU. A surface plasmon resonance (SPR) sensor based on symmetrical side-polished dual-core photonic crystal fiber (DC-PCF) with a wide refractive index (RI) detection is proposed and analyzed. A gold layer is placed on the symmetrical side-polished surface of photonic crystal fiber to excite the surface plasmon polaritons (SPPs). The proposed DC-PCF consists of the symmetrical air-holes and symmetrical side-polished structure. The design without air holes on both sides of the core can efficiently realize phase matching between the core guided mode and the plasma mode. Numerical simulation results show a maximum sensitivity as high as 8000 nm/RIU (refractive index unit) with a resolution of 1.3 × 10−5 RIU. It has a significant advantage in the field of chemical and biological detection because it is able to detect the analyte RI in the range of 1.3–1.42. [ABSTRACT FROM AUTHOR]

[Display omitted] • Here Darcy-Forchheimer relation is accounted in flow of viscous fluid. • Soret and Dufour effects are considered. • Chemical reaction is addressed in concentration equation for the mass transfer analysis. • Numerical results are obtained via Shooting method. The main purpose of this work is to analyze chemically reactive Darcy-Forchheimer nanoliquid flow towards a stretched surface. Buongiorno's model is utilized for the nanoliquid importance. Additionally, Soret and Dufour characteristics are also considered. Gyrotactic microorganisms with chemically reactive flow are considered. The given partial differential systems are converted into dimensionless ordinary expressions with the implementation of suitable transformation. Non-dimensional systems are solved through Newton built in-shooting technique. Graphical outcomes for temperature, microorganisms' field, velocity and concentration versus secondary variable are discussed. Numerical outcomes of drag force, density number and heat transport rate for sundry parameters are examined. A reduction occurs in velocity for higher porosity variable. Higher estimation of Dufour number upsurges the temperature. Similar impact for temperature is seen for random motion and thermophoresis variables. Concentration upsurges for higher Soret number, while reverse effect holds for Schmidt number. An increment in heat transport rate occurs for higher Dufour number. Microorganisms' fluid diminishes for higher Peclet number, while reverse impact seen for density number. [ABSTRACT FROM AUTHOR]

Application of a continuum damage mechanics formulation rests on the ease with which the material constants involved in the formulation can be determined. For an initially linear elastic material, the changes in elastic constants induced by damage depend on certain damage related material constants that are commonly determined by experiments in addition to those required to determine the initial properties. This additional experimental task can render the continuum damage mechanics theory less attractive. The present paper will only deal with those associated with damage representation. We propose here a procedure for analytically determining seven out of eight damage related material constants for unidirectional composites assumed initially transversely isotropic and containing a parallel array of matrix cracks along fibres. The remaining constant can be determined experimentally or by a numerical experiment proposed here for the purpose. The analytical expressions derived are in terms of initial elasticity constants of a unidirectional composite and are verified for their accuracy by numerical experiments. Since a unidirectional composite forms a building block in composite laminates, the results obtained here can be naturally used for damage in laminates. [ABSTRACT FROM AUTHOR]