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This paper addresses the investigation of axisymmetric thermally induced vibrations in Functionally Graded Material (FGM) cylindrical shells. It considers temperature-dependent (TD) properties and geometric non-linearity (the von Karman effect). The study systematically solves a transient heat conduction equation using finite differences method and the Crank–Nicolson method. During the heating stages, the evaluation of thermal forces and moments takes place. Equations of motion are derived through the application of Hamilton's principle. Spatial dependencies are discretized using the generalized Ritz method, while temporal dependencies are approximated using the β -Newmark method with Newton–Raphson linearization. A comparative analysis validates the procedure's efficiency and precision. Parametric studies explore the influence of parameters, including the temperature-dependency material properties, geometric nonlinearity, and shell's power-law index, providing valuable insights into FGM shell behavior under thermal shock. [ABSTRACT FROM AUTHOR]

In this research, the thermally induced vibration of the plates on the elastic foundation has been investigated. The plate is made of functionally graded materials (FGMs) that is graded along the thickness. All mechanical and thermal properties dependent on temperature are taken into account. To apply the temperature dependence of thermomechanical properties, the well-known Touloukian equation is used. The two-parameter elastic foundation, Winkler–Pasternak, is considered to be linear, isotropic, and homogeneous. The general formulation and equations governing the phenomenon of thermally induced vibration have been written under the assumptions of linear uncouple thermoelasticity. The one-dimensional transient heat conduction equation has been discretized with the help of the finite element method in the direction of thickness, and it has been solved over time by applying the Crank–Nicolson method. Also, the thermally induced force and moment resultants in each time step have been calculated based on the temperature profile. To obtain the equations of motion, Hamilton's principle based on the first-order shear deformation theory has been used, and the obtained equations and boundary conditions have been discretized by applying the generalized differential quadrature (GDQ) method and solved by using Newmark time marching scheme. [ABSTRACT FROM AUTHOR]

The frequency security issue has become more critical in recent decades for various reasons, especially the reduced and degraded primary frequency control (PFC) response of traditional participants based on the economic incentives of generation units to earn more profit in the energy market. Since frequency security is a dynamic phenomenon, incorporating it into an optimization problem such as scheduling is complicated, especially with realistic modeling assumptions. This difficulty can be solved using a variety of solutions ranging from simple and inaccurate static methods to complex and accurate dynamic approaches. This paper proposes a competitive mechanism among participants in real-time scheduling (hour-ahead) that integrates the dynamic frequency security in the economic optimization procedure, hence enhancing the frequency security. The proposed formulation is a rescheduling scheme based on optimal power flow (OPF) which clears the energy and reserve simultaneously and considers the network constraints. Also, this mechanism uses the accurate model of the governors by including all of the influential parameters on PFC. The cutting-plane model of the nadir frequency function is used to resolve the complexity of the optimization problem. In addition, a framework for multi-objective optimization has been developed that enables the policymakers to reconcile the frequency security with the rescheduling cost. Finally, the correctness and the efficiency of the proposed framework are demonstrated from the economic and technical perspectives based on the implementation of the IEEERTS. [ABSTRACT FROM AUTHOR]

Vortex mediated turbulence can be the key element in the generation of extreme events in spatially extended lasers with optical injection. Here, we study the interplay of vortex mediated turbulence and cavity solitons on the onset of extreme events in semiconductor lasers with injection. We first analyze and characterize these two features separately, spatiotemporal chaotic optical vortices for low values of the injection intensity and cavity solitons above the locking regime. In regimes where vortex mediated turbulence and cavity solitons coexist, localized peaks of light inhibit instead of enhancing the generation of rogue waves by locally regularizing the otherwise chaotic phase of the optical field. Cavity solitons can then be used to manipulate and control extreme events in systems displaying vortex mediated turbulence. [ABSTRACT FROM AUTHOR]

This study aims to search the new soliton solutions of the Stochastic Chiral nonlinear Schrödinger equation. All calculations and graphing are performed using powerful symbolic computational packages in Mathematica software. [ABSTRACT FROM AUTHOR]

This study deals with the nonlinear bending analysis of elastic tubes made of functionally graded (FG) porous material based on modified couple stress theory. Immovable simply supported and clamped boundary conditions are assumed for the FG porous microtubes resting on nonlinear elastic foundation. Transverse pressure load is applied uniformly on the upper surface of the microtube which is exposed to uniform temperature field. Temperature-dependent material properties of the microtube with uniformly distributed porosity are graded across the radius of the cross-section. The higher-order shear deformation theory of circular beams is presented to approximate the displacement field. The von Kármán type of kinematic assumptions is utilized for nonlinear strain-displacement relations. The uncoupled thermoelasticity theory is used to derive the constitutive equations. With the establishment of the virtual displacement principle, nonlinear differential equations governing the equilibrium position of the microtube are extracted. These equilibrium equations are analytically solved by means of the two-step perturbation technique and Galerkin procedure. Parametric investigations are performed to demonstrate the size-dependent nonlinear bending responses of an FG porous microtube on nonlinear elastic foundation in thermal environment. [ABSTRACT FROM AUTHOR]

The generalized exponential rational function method, which is one of the strong methods for solving nonlinear evolution equations, is applied to the conformable resonant nonlinear Schrödinger's equation in this study. This equation plays a significant role in nonlinear fiber optics. It also has many important applications in photonic crystal fibers. The procedure implemented in this paper can be recommended in solving other equations in the field. All calculations and graphing are performed using powerful symbolic computational packages in Mathematica software. All calculations and graphing are performed using powerful symbolic computational packages in Mathematica software. [ABSTRACT FROM AUTHOR]

A nonlinear Schrödinger equation describing the polarization mode in an optical fiber which involves different physical terms such as quintic nonlinearity, self-steepening effect, and self-frequency shift is investigated in the present paper. The study goes on by adopting a field function and effective ansatzes to arrive at a highly nonlinear ODE which is formally solved with the help of the modified Kudryashov and e x p a -function methods. As a result, a series of chirped optical solitons along with nonlinear chirps is retrieved, confirming the fantastic performance of schemes. [ABSTRACT FROM AUTHOR]

By numerical simulation of a cavity filled with triple quantum dot molecules under tunneling induced transparency, we show that various regimes of existence of different kinds of cavity solitons are possible. Forming in overlapping regions of a multistable parameter space, cavity solitons in this system exhibit different dynamical behaviors: stationary on a flat background when there is only one cavity soliton branch, oscillating when two cavity soliton branches coexist, and stationary-rambling on a honeycomb background arising from simultaneous presence of a stable pattern and a cavity soliton branch. In particular, we show that three different types of dissipative localized structures can be excited in multistable regions where material coherence is high due to light-matter interaction processes. [ABSTRACT FROM AUTHOR]

A nonlinear analysis on the thermal-mechanical coupling bending behavior of functionally graded porous curved micro-tubes is performed in this research. The case of curved micro-tubes with doubly-clamped boundary conditions resting on nonlinear elastic foundation is considered. Based on the modified couple stress theory, curved micro-tubes under uniformly distributed transverse pressure and uniform temperature rise are analyzed. It is assumed that the material properties of the curved micro-tube are temperature-dependent and graded across the radius of cross-section. The governing equations of the curved micro-tube are established within the framework of higher-order shear deformation theory and the von Kármán kinematic assumptions. These equations are reformulated for the case of curved micro-tubes with even distributed porosities based on the uncoupled thermoelasticity theory. The system of nonlinear differential equations governing the equilibrium position of curved micro-tubes is solved using the two-step perturbation technique. The analytical solutions are given in this study to obtain the large deflection in curved micro-tubes as an explicit function of the thermal/mechanical load. The influences of porosity volume fraction, power law index, microstructural length scale parameter, foundation stiffness, and geometrical parameters on the thermomechanical deflection of curved micro-tubes are investigated. [ABSTRACT FROM AUTHOR]

• Thermomechanical bending behavior of FG porous infinite length cylindrical panels is analyzed. • Two-step perturbation technique is employed to analyze the large deflection of clamped shells. • Interaction of the shear deformable shell with a nonlinear elastic foundation is taken into account. • The present formulations are based on the physical neutral surface and nonlocal strain gradient theory. The present paper investigates the nonlinear static bending behavior of infinite length cylindrical panels made of functionally graded porous (FGP) materials. The shell with clamped edges is subjected to uniform temperature rise and transverse pressure loading. Thermomechanical properties of the shell with even distributed porosities are temperature-dependent and are graded along the thickness. The principle of virtual displacement and nonlocal strain gradient theory (NSGT) are employed to derive the equilibrium equations of the shallow shell resting on nonlinear elastic foundation. The concept of physical neutral surface (PNS) and higher-order shear deformation theory are also included into the formulation. Using the uncoupled thermoelasticity and Donnell kinematic assumptions, three differential equations of the shell under thermomechanical loading are established. The nonlinear system of governing equations is solved for the shell with infinite length which is clamped on both straight edges and free at other curved edges. The two-step perturbation technique and Galerkin procedure are employed to derive analytical solutions for the thermal, mechanical, and thermomechanical responses of cylindrical panels. The important parameters governing the bending behavior of shells under thermal-mechanical coupling load are identified and discussed. Parametric studies are given to show the influences of nonlocal/length scale parameter, porosity coefficient, foundation stiffness, geometrical parameter and functionally graded pattern. It is shown that the geometrical parameters have an important role on the bending behavior of cylindrical panels. Also, the temperature dependence of material properties results in higher deflection of the heated shells. [ABSTRACT FROM AUTHOR]

In this review, the numerous possible mechanisms that provide supportive evidence for how colonic dysbiosis denotes metabolic dysfunction, dysregulates glucose homeostasis and leads to diabetes mellitus and related metabolic disorders are defined. Information was gathered from articles identified by systematic reviews and searches using Google, PubMed and Scopus. The composition of the colonic microbiota plays an integral role in maintaining host homeostasis by affecting both metabolic activities and underlying functional gene transcription in individuals with diabetes and related metabolic disorders. Increased colonic microbiome‐derived concentrations of lipopolysaccharides, also known as 'metabolic endotoxaemia', as well as alterations in bile acid metabolism, short‐chain fatty acids, intestinal hormones and branched‐chain amino acid secretion have been associated with the diverse production of pro‐inflammatory cytokines and the recruitment of inflammatory cells. It has been shown that changes to intestinal bacterial composition are significant even in early childhood and are associated with the pathogenesis of both types of diabetes. We hope that an improved understanding of related mechanisms linking the colonic microbiome with glucose metabolism might provide for innovative therapeutic approaches that would bring the ideal intestinal ecosystem to a state of optimal health, thus preventing and treating diabetes and related metabolic disorders. [ABSTRACT FROM AUTHOR]

An imperfection sensitivity analysis for the nonlinear post-buckling behavior of functionally graded (FG) porous micro-tubes is performed in this research. The case of geometrically imperfect micro-tubes surrounded by a nonlinear elastic medium under axial compressive load is analyzed. Properties of the micro-tube with uniform distributed porosity are FG across the radius of the cross-section. Two types of boundary conditions as simply-supported and clamped are considered. The high-order shear deformation theory of tubes is utilized to approximate the displacement field. Differential equations governing the equilibrium position of the micro-tube are extracted using the virtual displacement principle. These nonlinear equations are analytically solved by means of the two-step perturbation technique and Galerkin procedure. It is shown that when the imperfect micro-tube is in contact with a sufficiently soft foundation, the post-buckling path of the structure is unstable, and therefore the structure is imperfection sensitive. Since the imperfection sensitivity of micro-tubes is not reported in literature, results of this study are compared with buckling responses of perfect FGM tubes. The effects of porosity coefficient, power law index, length scale parameter, and geometrical parameters upon the limit buckling load of imperfect micro-tubes are investigated. [ABSTRACT FROM AUTHOR]

• Transient CFD modeling of solar stills is performed with instantaneous weather data. • Species and energy equations are coupled by defining latent heats as source terms. • Temperature, velocity and mass fraction distributions are obtained through a day. • Effect of different parameters on performance of passive solar basins are investigated. • Stepped solar basins are optimized geometrically. A transient CFD model is developed to investigate the parameters affecting the productivity of a solar still. Instantaneous weather data is accounted as boundary conditions while the absorption of solar irradiance, as well as radiative heat transfer is considered by DO equation. Evaporation and condensation rates are evaluated by solving species transport equation for water vapor and application of Fick's law. Latent heats are added to the energy equation as sink and source terms by considering a coefficient that accounts for the latent heat shared between neighboring bodies. Effects of wind speed, glass cover thickness, water depth, water to cover distance and cover inclination on performance of a passive solar still are investigated. Stepped solar stills are also modeled and effects of number of steps and water to cover distance are discussed. Results show that a 14.4% increase in the productivity is observed when the wind speed increases from 1 m/s to 6 m/s, and a 3.5% improvement occurs by decreasing the glass thickness from 4 mm to 2 mm. The optimum values of water depth and water to cover distance are found to be 2 and 8 cm respectively, with the cover tilt equal to the local latitude angle. Moreover, by converting the basin solar still to the appropriate stepped solar still, the productivity increases about 17.4%. [ABSTRACT FROM AUTHOR]

Background Studies in the adjuvant setting suggest that the timing of breast cancer diagnosis, surgery, and chemotherapy might affect outcomes. In the neoadjuvant setting, data exploring whether expeditious neoadjuvant chemotherapy (nac) after diagnosis improves the rate of pathologic complete response (pcr) in breast cancer are limited. Methods Patients who received nac and completed treatment between May 2012 and December 2018 were identified from a prospectively collected database at BC Cancer. Time from diagnosis to start of nac was calculated. Patients were grouped into those who did and did not experience a pcr, and those who started nac within 28 days or after 28 days [time to nac (ttn)]. The association between pcr and ttn was tested using logistic regression. Results In the time period studied, 482 patients who received nac were identified. After exclusions, 421 patients met the eligibility criteria. Median time from biopsy to chemotherapy was 33 days (range: 7-140 days). In 149 patients (35.4%), nac was received within 28 days of diagnosis (range: 7-28 days); in 272 patients (64.6%), it was received after more than 28 days (range: 29-140 days). The overall pcr rate was 31.8%. A trend toward a higher pcr rate, although not statistically significant, was observed in the group that initiated chemotherapy within 28 days (34.2% vs. 30.5%, p = 0.43). In the logistic regression model, rates of pcr were associated with receptor status, but not age, stage, or ttn. Conclusions In the neoadjuvant setting, we observed no difference in the rate of pcr in patients who started nac within 28 days or after 28 days. [ABSTRACT FROM AUTHOR]

In the last decade, different conductive networks for cooling heat generating bodies have been proposed, analyzed, and optimized. Links of a highly conductive material collect the heat generated in an area and conduct it to a heat sink. The important design point is how to dedicate the limited and expensive high conductivity material to each link. Although optimizations have been performed for heat generating bodies of different shapes separately, the lack of a general method is quite obvious in the literature. Therefore, an analytical general solution for optimal distribution of highly conductive material in networks of arbitrary configuration is developed in the present article. The proposed method gives the optimum thickness of each link with a simple expression, which only depends on the geometry of heat generating bodies. Moreover, it is mathematically proved that total thermal resistance of the optimal links is a function of Bejan's parameter k⁁φ and a purely geometrical function. This achievement greatly simplifies the design and optimization of any conductive cooling network. Results of the present simple formulation for configurations of various geometries are completely consistent with the available analytical and numerical solutions. [ABSTRACT FROM AUTHOR]

As photovoltaic (PV) power plants become more popular, it is important to understand how wind affects the temperature distribution and consequently performance of modules placed in different rows of a PV array. This study conducts a comprehensive three dimensional CFD simulation for two 5 by 10 PV arrays (with and without inter-row module spacing) to assess the effects of wind on PV array power output. By solving the continuity, momentum, and energy equations simultaneously, the temperature distribution in the PV modules and the surrounding air along with the resulting velocity profiles are obtained and investigated for two wind directions (northerly and southerly) and two wind speeds of 2 and 5 m/s. The electrical output of PV modules for the respective cases are then compared. The results show that the PV array with zero inter-row module spacing performs better under northerly wind and experiences a 5.3% increase in power output with increasing wind speed. However, the PV array with 3 cm spacing performs better under southerly wind and experiences a 4.6% increase in power output with increasing wind speed. It is found that the PV array with inter-row spacing generally performs better than the one with zero inter-row module spacing. • Three-dimensional CFD simulations of different PV array configurations are performed. • The effects of wind conditions on the temperature distribution and performance of each PV module are studied. • The electrical output of each PV module are compared for the respective cases. [ABSTRACT FROM AUTHOR]

Considering the third-order shear deformation and physical neutral plane theories, thermal postbuckling analysis for functionally graded (FG) porous beam are performed in this research. The cases of shear deformable functionally graded materials (FGM) beams with initial deflection and uniformly distributed porosity are considered. Geometrically imperfect FG porous beams with two different types of immovable boundary conditions as clamped–rolling and clamped–clamped are analyzed. Thermomechanical nonhomogeneous material properties of the FG porous beam are assumed to be temperature and position dependent. FG porous beams are subjected to different types of thermal loads as heat conduction and uniform temperature rise. Heat conduction equation is solved analytically using the polynomial series solution for the one-dimensional condition. The governing equilibrium equations are obtained by applying the virtual displacement principle. Assuming von Kármán type of geometrical nonlinearity, equilibrium equations are nonlinear and are solved using an analytical method. A two-step perturbation technique is used to obtain the thermal buckling and postbuckling responses of FG porous beams. The numerical results are compared with the case of perfect FGM Timoshenko beams without porosity distribution based on the midplane formulation. Parametric studies of the perfect/imperfect FG porous beams for two types of thermal loading and boundary conditions are provided. [ABSTRACT FROM AUTHOR]

In this study, a complete three-dimensional computational fluid dynamics simulation of fluid flow and heat transfer from a Photovoltaic (PV) module is developed. Since the electrical efficiency of photovoltaic modules is a function of its temperature, the present research tries to calculate the temperature distribution in the module by numerically solving the governing momentum and energy equations with the finite element method. The three dimensional wind flow field around the system is simulated in different geometrical and ambient conditions to account for realistic and nonuniform convection heat transfer from the module surfaces. The electrical output power is calculated as a function of PV module temperature and is modeled as a negative source term in the energy equation. Results show that the present method is very successful in predicting the temperature distribution and output power of photovoltaic modules at various geometrical and environmental conditions. Specifically, the effect of wind direction and tilt angle of the PV module is investigated. By increasing the tilt angle at wind velocities higher than 1 m/s, the average PV temperature increases by about 4 K; as a result, its efficiency decreases. The most favorable wind direction is 90° as a 3 K cooling in the average PV module temperature can be achieved. The proper choice of mounting orientation is also important, and it depends on the wind direction. In most cases, the horizontal mounting (i.e., the longer side of the panel is parallel to the ground) results in better cooling. [ABSTRACT FROM AUTHOR]

Based on the modified couple stress theory, an attempt is made in this study to analyze the nonlinear snap-through instability of shallow sandwich arches. The microstructure-dependent functionally graded material (FGM) arch with surface bonded piezoelectric actuator layers is analyzed. The piezo-FGM sandwich arch is subjected to uniform transverse pressure load in thermo-electrical environment. All material properties of the FGM micro arch are assumed to be temperature- and position-dependent. The governing equilibrium equations of the piezo-FGM sandwich arch are established with the aid of virtual displacement principle and the uncoupled thermoelacticity theory. The obtained governing differential equations are based on the first-order shear deformation shallow arch theory of the Timoshenko and von Kármán nonlinear assumptions. These equilibrium equations contain three coupled ordinary differential equations in terms of displacements. The nondimensional governing equations are solved for the cases of piezo-FGM sandwich arches with simply supported and clamped boundary conditions by using the two-step perturbation technique. Analytical closed-form solutions are derived to give the deflected shape of the piezo-FGM sandwich arch with immovable ends. Comparison is made with the existing results for the cases of FGM arch without couple stress and piezoelectric layers, where good agreement is obtained. The nonlinear behavior of the sandwich arches is highly affected by the couple stress, piezoelectric layers, temperature change, volume fraction index, and geometrical properties of the arch. [ABSTRACT FROM AUTHOR]

Herein, functionalized spiro[indoline-3,5′-pyrazolo[1,2-a]pyridazine]-7′-carbonitrile containing two contiguous chiral stereocenters was efficiently synthesized in a satisfactory yield (up to 91% yield) and with excellent diastereoselectivity. We have reached this satisfactory yield by DABCO-catalyzed [3+3] annulation reactions of an isatin N,N′-cyclic azomethine imine 1,3-dipole with a Knoevenagel intermediate in dichloromethane (DCM) as solvent at ambient temperature; this was an entirely new strategy for creating one quaternary stereogenic center at the position-3 of an oxindole structure using an abnormal tandem Michael addition, N-cyclization, and a unique approach via the azomethine imine 1,3-dipole. Furthermore, in the proposed synthetic protocol, traditional chromatography and recrystallization purifications were avoided by washing away the crude products with cold diethyl ether such that the pure product could be obtained shortly and easily after the experiment. The X-ray crystallographic data confirmed the structure of the typical product. [ABSTRACT FROM AUTHOR]

Based on the modified couple stress theory, nonlinear thermally induced large deflection analysis of shallow sandwich arches is studied. A functionally graded material (FGM) micro-arch with piezoelectric layers integrated into the surfaces and with immovable pinned and fixed edges is analyzed. Temperature and position dependence of the thermomechanical properties for an FGM micro-arch are taken into account. The piezo-FGM arches are subjected to different types of thermal loads such as uniform temperature, linear temperature, and heat conduction. A modified couple stress theory is combined with the uncoupled thermoelasticity assumptions to derive the governing equations of the arch by using the virtual displacement principle. The von Kármán type of geometrical nonlinearity and first-order shear deformation theory are also used to obtain the equilibrium equations. The nonlinear governing equilibrium equations of the piezo-FGM sandwich arch under different thermal loads are solved analytically. The solutions of the system of ordinary differential equations for both cases of boundary conditions are established by employing the two-step perturbation technique. Comparison is made with the existing results for the cases of FGM arch without couple stress and piezoelectric layers under uniform temperature rise, and good agreement is obtained. Also, parametric studies are proposed to show the effects of couple stress, piezoelectric layers, volume fraction index, geometrical parameters, and temperature dependence, the thermally induced deflection of the piezo-FGM sandwich arch. [ABSTRACT FROM AUTHOR]

The stone monuments of Pasargadae (c.550 to 330 bce), Iran, represent a unique example of an advanced construction system that used stones as building materials. This study characterizes the mineralogical and chemical composition of these stones and determines their provenance. Five samples were obtained from buildings at Pasargadae and studied using optical microscopy (OM), X‐ray powder diffraction (QXRD), inductively coupled plasma‐mass spectrometry (ICP‐MS) and X‐ray fluorescence (XRF). Their chemical and mineralogical composition was determined using the Sr/Fe ratio and the amount of Ce, Dy, Er, Eu, Gd, La, Nd, Pr, Sm, Tb, Tm, Yb and Lu in order to investigate the provenance of the building materials. Seven additional samples were obtained from rock outcrops suspected of being the source of the rock and studied using the same techniques. A statistical principal component analysis (PCA) exhibited correlations between each data set. The data suggest that Abolverdi quarry west of Pasargadae served as the source for the light limestone used in the construction of the buildings, particularly the Tomb of Cyrus the Great. The Ahmad‐Beigi and Sarpaniran outcrops to the north‐east and south‐east are suggested as the sources of the dark limestone. The Sr/Fe ratio and the amount of rare‐earth elements distinguish the samples by means of different geneses. [ABSTRACT FROM AUTHOR]

Highlights • A comprehensive thermal analysis is presented for water harvesting from humid air using TEC. • The device is optimized for different ambient temperatures, air flow rate and electrical current. • The system is capable of producing 26 ml/h of water from air with 75% relative consuming only 20 W power. • Annual performance of the system is also optimized for three southern cities in Iran. • Results show that the proposed design is the most energy efficient system among similar devices in high relative humidity. Abstract Condensation of water vapor available in atmospheric air can be considered as a solution for water scarcity problem. In this paper, a comprehensive thermodynamic analysis of water production from humid air using thermoelectric coolers (TECs) is presented. The system consists of a number of thermoelectric coolers, a fan to supply the required air flow circulation, two cold and hot air channels, heat sinks and solar cells for powering the thermoelectric coolers and fan. Effects of various design parameters are investigated and discussed. The proposed design is optimized to get the maximum effectiveness which is defined as the amount of produced water per unit of energy consumption. Sensitivity analysis is used to find the optimum number of TECs, length of the channels and performance of the system at different temperatures. The resulting system is capable of producing 26 ml of water within 1 h from the air with 75% relative humidity and the temperature of 318 K by consuming only 20 W of electrical power. In addition, the annual performance and optimization of this device in three southern cities of Iran are presented based on hourly meteorological data. Finally, comparison of the present system with other air water generators indicates that the proposed design is the most energy efficient system among similar devices especially in high relative humidity. [ABSTRACT FROM AUTHOR]

Although photovoltaic-thermoelectric generator hybrid systems (PV-TEG) are intended to increase the power generation in solar photovoltaic systems, the attachment of TEG can negatively affect the temperature distribution in PV cells. Therefore, a numerical model is developed in this paper to research the effects of TEG on the performance of hybrid PV-TEG systems. Nine hybrid systems are considered including PV-TEG with three types of TEG modules in two different arrangements, as well as a multijunction concentrating photovoltaic cell (CPV) combined with TEG modules (CPV-TEG). The resulting temperature distribution and power generation are discussed in different cooling conditions and concentration ratios. The effects of TEG type and arrangement, heat transfer coefficient, and concentration ratio are scrutinized. The present results show that only two systems achieve a marginal performance improvement in certain conditions, compared to their equivalent PV systems with the same cooling condition. The maximum performance improvement of 0.57% corresponds to C-49 CPV-TEG system, while the maximum negative effect is 3.04% for C-71. A one-day transient simulation is also provided for two selected systems. It is revealed that the overall daily performance is almost unchanged in the PV-TEG system, while the CPV-TEG system performs better if a weaker cooling system is utilized. [ABSTRACT FROM AUTHOR]

Geometrically non-linear thermally induced vibrations of functionally graded material (FGM) joined spherical-conical shells are analyzed in the current research. Thermo-mechanical properties of the shells are assumed to be temperature and position dependent. The system of joined spherical-conical shells is subjected to thermal shock on the ceramic-rich surface, whereas the metal-rich one is kept at reference temperature. The one-dimensional transient heat conduction equation is established and solved via the generalized differential quadrature (GDQ) and Crank-Nicolson methods. This equation is non-linear since the thermo-mechanical properties of the shells are temperature dependent. The total functional of the shells is obtained under the assumptions of uncoupled thermoelasticity laws, first order shear deformation shell theory, and the von Kármán type of geometrical non-linearity. Non-linear coupled equations of motion are solved via the iterative Picard method accompanied with the β-Newmark time approximation technique. Numerical results are well-validated with the available data for the case of single FGM spherical shell. Parametric studies are conducted to examine the influences of conical and spherical shell geometries, material composition, temperature dependence, in-plane and out-of-plane mechanical boundary conditions, various configuration of conical/spherical shell system, and thermal boundary conditions. It is highlighted that thermally induced vibrations indeed exists. [ABSTRACT FROM AUTHOR]

The present paper is aimed to make a detail analysis on the correct simulation of the associated natural thermal boundary conditions and their interesting effects on the thermally nonlinear generalized thermoelastic response of a continuum medium. The paper presents some explanations regarding the literally conventional thermal boundary conditions associated with Cattaneo's heat conduction law. The importance of modeling the natural thermal boundary conditions is investigated by applying three practical thermal loads to a homogeneous one-dimensional layer. The results of the investigations are illustrated by propagation of thermoelastic waves through the layers. These results clearly show the profound effects of the correct statement of natural thermal boundary conditions on the thermoelastic response of the layer. It is shown that these effects intensify the importance of thermally nonlinear generalized thermoelastic analyses. [ABSTRACT FROM AUTHOR]

This article addresses a clarification study on thethermally nonlinearFourier/ non-Fourier dynamic coupled (generalized) thermoelasticity. Based on the Maxwell-Cattaneo’s heat conduction law and the infinitesimal theory of thermoelasticity, governing equations for the thermally nonlinear small deformation type of generalized thermoelasticity are derived. The Bubnov–Galerkin scheme is implemented for spatial discretization. The spatially discretized equations are directly discretized in time domain using the fully damped Newmark method. The Newton–Raphson procedure is used to linearize the finite element equations. The layers are exposed to a thermal shock, so that the displacement, temperature, and stress waves propagate in layers. The effects of the time evolution, thermoelastic coupling, and thermal relaxation time on the response of the layers are investigated. Results reveal the significance of the thermally nonlinear analysis of generalized thermoelasticity for the conditions where large temperature elevations exist. [ABSTRACT FROM PUBLISHER]

Energy storage is one of the most important components of renewable energy systems. Among different methods, thermal energy storage (TES) in forms of sensible or latent has been the subject of many studies in the past decades. The main difficulty in optimal design of storage tanks is associated with low thermal conductivity of the storing (solid or phase change) material. In fact, the distribution of thermal energy from a source to the body of storing material poses a volume to point problem which is the subject of constructal theory. Therefore, the objective of the present paper is to investigate the transient behavior of a rectangular thermal energy storage tank equipped with fin configurations optimized for heat conduction based on constructal theory. Results of numerical simulations reveal that the more complex configurations perform better in sensible TES systems; almost as well as what is expected based on analytical steady state solutions. However, because of the convection currents in the melting process of a PCM tank, the final full charging time of the latent systems are approximately the same. [ABSTRACT FROM AUTHOR]

Contents The purpose of the present experiment was to investigate the protective effects of palmitoleate on the quality of ram semen during low temperature liquid storage. Ejaculates were collected using the artificial vagina from four Qezel rams twice a week. Ejaculates were pooled, diluted with Tris-egg yolk extender without palmitoleate (control) or supplemented with 0.125 (P 0.125), 0.25 (P 0.25), 0.5 (P 0.5) and 1 (P 1) mM palmitoleate at a final concentration of 500 × 106 spermatozoa/ ml. Total motility and forward progressive motility ( FPM) as well as other spermatozoa kinematics were evaluated by computer-assisted sperm analysis. Moreover, viability and membrane functionality were determined in the spermatozoa. Additionally, amounts of malondialdehyde ( MDA), total antioxidant activity ( AOA), nitric oxide ( NO) and superoxide dismutase ( SOD) activities were evaluated in the medium and spermatozoa at 0, 24, 48 and 72 hr of storage. The palmitoleate supplementation resulted in a significant ( p < .05) increase in total motility and FPM with the highest increase at 0.5 mM concentration for 72 hr. P 0.5 group also resulted in the highest percentage of membrane-intact spermatozoa (76.60 ± 1.95%) and viability (75.81 ± 1.34%) at 72 hr ( p < .05). The amounts of MDA and NO were lower in P 0.125, P 0.25 and P 0.5 groups compared to control at 48 hr and 72 hr ( p < .05). Higher amounts of AOA were obtained in palmitoleate-treated groups in medium and spermatozoa during storage time ( p < .05). Furthermore, palmitoleate supplementation increased the SOD activities in spermatozoa compared to the control ( p < .05). The results of the present experiment reveal that supplementation with 0.5 mM palmitoleate improves ram spermatozoa motion characteristics, AOA levels and SOD activities during liquid storage. Then, palmitoleate could be used as an antioxidant source during liquid storage of ram semen. [ABSTRACT FROM AUTHOR]

Generalized thermoelasticity response of an annular disk subjected to thermal shock on its inner surface is analyzed in this research. The Lord–Shulman theory, which accounts for one relaxation time in the conventional Fourier law, is used to avoid the infinite speed of thermal wave propagation. Unlike the other available works in which the first law of thermodynamics is linearized, the nonlinearity arising from the temperature change is taken into consideration. The first law of thermodynamics in this case becomes nonlinear and the analysis under such formulation is calledthermally nonlinear. Two coupled equations, i.e., the radial displacement wave equation and temperature wave propagation equation are obtained. These equations and the associated boundary conditions are discreted through the generalized differential quadrature method. Solution of the time-dependent system of equations is obtained using the Newmark time marching scheme and the successive Picard method. Numerical results are provided for both thermally linear and thermally nonlinear temperature and radial displacement wave propagations. Parametric studies reveal that at higher temperature levels, thermally nonlinear first law of thermodynamics should be considered instead of thermally linear one. Furthermore, the higher the coupling parameter and/or relaxation time, the higher the divergence of thermally nonlinear-/linear-based results. [ABSTRACT FROM PUBLISHER]

Liquid storage of avian spermatozoa is currently being employed in programs utilizing the artificial insemination to optimize the management of genetically superior males. It is mandatory to use efficient semen storage techniques in order to prevent the reduction of the fertilizing ability of stored semen. The present study was designated to evaluate the effect of oleic acid on rooster semen quality stored at 4°C for 48 h. Semen was collected from 10 roosters twice a week. Good quality ejaculates were pooled and after dilution, the semen was enriched with 0 (control), 0.125 (O 0.125), 0.25 (O 0.25), 0.5 (O 0.5), and 1 (O1) millimolar oleate. Forward progressive motility and viability of spermatozoa were evaluated at 0, 24, and 48 h. Moreover, malondialdehyde (MDA) and total antioxidant activity (AOA) levels were measured in seminal plasma and spermatozoa at the mentioned time points. Motility was 80.33 ± 1.45, 80.00 ± 2.08, and 66.00 ± 2.30% at 24 h and 56.33 ± 1.45, 57.33 ± 2.18, and 41.33 ± 2.02% at 48 h in O 0.125, O 0.25, and control, respectively (P < 0.001). Total AOA concentrations of seminal plasma were significantly higher in oleate treated groups than the control at 24 and 48 h (P < 0.03). Moreover, concentrations of AOA in spermatozoa revealed that oleate treated group showed higher AOA values compared to the control group at 24 and 48 h (P < 0.001). MDA concentrations of seminal plasma and spermatozoa were lower in oleate treated groups in comparison with control group at 24 and 48 h (P < 0.05). In conclusion, rooster semen enrichment with low doses of oleate would exert beneficial effects on the quality of semen during cooled storage. [ABSTRACT FROM AUTHOR]

Today, conductive volume to point cooling of heat generating bodies is under investigation as an alternative method for thermal management of electronic chipsets with high power density. In this paper, a new simple geometry called “parallel design” is proposed for effective conductive cooling of rectangular heat generating bodies. This configuration tries to minimize the thermal resistance associated with the temperature drop inside the heat generating volume. The geometric features of the design are all optimized analytically and expressed with simple explicit equations. It is proved that optimal number of parallel links is equal to the thermal conductivity ratio multiplied by the porosity (or the volume ratio). With the universal aspect ratio of H / L = 2, total thermal resistance of the present parallel design is lower than the recently proposed networks of various shapes that are optimized with help of numerical simulations; especially when more conducting material is available. [ABSTRACT FROM AUTHOR]

The exact solutions often model natural phenomena and facilitate the testing of numerical algorithms as well as the stability analysis of differential equations. There is an interest for long times in obtaining exact analytical solutions of nonlinear evolution equations. In this paper, we investigate the coupled Schrodinger–Boussinesq equation and new soliton-like solutions are obtained for this equation via the direct algebraic method under certain constraints on the coefficient functions. [ABSTRACT FROM AUTHOR]

In this paper, one of the newest analytical methods, new homotopy perturbation method (NHPM), is considered to solve thermoelasticity equations. Results obtained by NHPM, which does not need small parameters, are compared with the numerical results and a very good agreement is found. This method provides a convenient way to control the convergence of approximation series and adjust convergence regions when necessary. The results reveal that the proposed method is explicit, effective and easy to use. [ABSTRACT FROM AUTHOR]

This paper presents the exact solutions for the fractional Korteweg-de Vries equations and the coupled Korteweg-de Vries equations with time-fractional derivatives using the functional variable method. The fractional derivatives are described in the modified Riemann-Liouville derivative sense. It is demonstrated that the calculations involved in the functional variable method are extremely simple and straightforward and this method is very effective for handling nonlinear fractional equations. [ABSTRACT FROM AUTHOR]

In this paper, we have presented the applicability of the first integral method for constructing exact solutions of (2+1)-dimensional Jaulent-Miodek equations. The first integral method is a powerful and effective method for solving nonlinear partial differential equations which can be applied to nonintegrable as well as integrable equations. The present paper confirms the significant features of the method employed and exact kink and soliton solutions are constructed through the established first integrals. [ABSTRACT FROM AUTHOR]

To create a roadmap for the industrial-scale production of sodium-22, various production routes of this radioisotope involving light charged-particle-induced reactions at the bombarding energy range of threshold to a maximum of 100 MeV have been calculated. The excitation functions are calculated by using various nuclear models. Reaction pre-equilibrium process calculations have been made in the framework of the hybrid and geometry dependent hybrid models using ALICE/ASH code, and in the framework of the exciton model using TALYS-1.4 code. To calculate the compound nucleus evaporation process, both Weisskopf–Ewing and Hauser–Feshbach theories have been employed. The cross sections have also separately been estimated with five different level density models at the whole projectile energies. A comparison with calculations based on the codes, on one hand, and experimental data, on the other hand, is arranged and discussed. [ABSTRACT FROM AUTHOR]

In this present paper, we aim to extend the applications of direct algebraic method to solve a perturbed nonlinear Schrodinger's equation with Kerr law nonlinearity. It is shown that the proposed method is effective and general. Many different new complex solitary solutions are obtained. Some previous results are extended. These complex solitary wave solutions are expressed by hyperbolic function, trigonometric functions are rational functions. [ABSTRACT FROM AUTHOR]

The present study examines the geometrically non-linear dynamic response of hermetic capsule construction made of functionally graded materials subjected to thermal shock. The Voigt and Toloukian models are used to derive the material properties, where dependence of the properties to position and temperature is included. The one-dimensional transient heat transfer equation is established. The Crank-Nicholson approximation and Picard's iterative method are used to solve this nonlinear equation using the GDQ numerical method in accordance with the temperature dependence of the material properties. After obtaining the temperature distribution along the thickness, it is possible to determine the thermal force and moment. Using the first-order shear theory to calculate the displacement field and the von Kármán form of geometry non-linearity, the equations of motion are determined. The Newton-Raphson iterative approach and the β -Newmark time estimate approach are used to solve the non-linear coupled equations of motion. The influencing factors on the reaction of the structure, such as the radius of the sphere and the length of the cylinder, the power law index, and the shell thickness are determined after the equations, techniques, and findings are validated. [ABSTRACT FROM AUTHOR]

In this paper, we construct the topological or dark solitons of Hirota equation by using the first integral method. This approach provides first integrals in polynomial form with a high accuracy for two-dimensional plane autonomous systems. Exact soliton solution is constructed through the established first integrals. This method is a powerful tool for searching exact travelling solutions of nonlinear partial differential equations (NPDEs) in mathematical physics. [ABSTRACT FROM AUTHOR]

The 22 Ne( p , n ) 22 Na is an optimal reaction for the cyclotron production of 22 Na. This work tends to monitor the proton induced production of 22 Na in a gas-cell target, containing natural and enriched neon gas, using Monte Carlo method. The excitation functions of reactions are calculated by both TALYS-1.6 and ALICE/ASH codes and then the optimum energy range of projectile for the high yield production is selected. A free gaseous environment of neon at a particular pressure and temperature is prearranged and the proton beam is transported within it using Monte Carlo codes MCNPX and SRIM. The beam monitoring performed by each of these codes indicates that the gas-cell has to be designed as conical frustum to reach desired interactions. The MCNPX is also employed to calculate the energy distribution of proton in the designed target and estimation of the residual nuclei during irradiation. The production yield of 22 Na in 22 Ne( p , n ) 22 Na and nat Ne( p , x ) 22 Na reactions are estimated and it shows a good agreement with the experimental results. The results demonstrate that Monte Carlo makes available a beneficial manner to design and optimize the gas targets as well as calibration of detectors, which can be used for the radionuclide production purposes. [ABSTRACT FROM AUTHOR]

This paper studies the dynamics of dispersive optical solitions that is modeled by the fourth order nonlinear Schrödinger's equation and Schrödinger–Hirota equation, the latter of which is considered with power law nonlinearity. Kudryashov's method is applied to obtain soliton solutions to the model equations. These results and the solution methodology makes a profound impact in the study of optical solitons. [ABSTRACT FROM AUTHOR]

This paper considers the resonant nonlinear Schrödinger's equation with dual-power law nonlinearity. The G ′/ G -expansion method is applied to integrate this equation. The soliton solutions are thus obtained. Both constant coefficients as well as time-dependent coefficients are considered. The results for parabolic law nonlinearity fall out as a special case. [ABSTRACT FROM AUTHOR]

This paper obtains solitons and singular periodic solutions to the generalized resonant dispersive nonlinear Schrödinger' equation with power law nonlinearity. There are several integration tools that are adopted to extract these solutions. They are simplest equation method, functional variable method, sine-cosine function method, tanh function method and the G'/G-expansion method. These integration techniques reveal bright and singular solitons as well as the corresponding singular periodic solutions to the nonlinear evolution equation. These solitons solutions are important in the nonlinear fiber optics community as well as in the study of rogue waves. [ABSTRACT FROM AUTHOR]

In the last decade, various conductive networks for cooling heat generating bodies have been proposed, analyzed, and optimized. Nevertheless, many of these studies have not been based on an analytical or mathematical formulation of the effective parameters. In this trend, a new geometry is assumed and analyzed (by analytical or numerical methods) hoping to decrease the total thermal resistance of the system. Therefore, the objective of the present paper is to illustrate how to analyze a conductive cooling network and improve it using the analytical procedures based on the general formulation of thermal resistance. /Is an example, the conventional rectangular elemental volumes with I shaped conductive link is modified to V shaped and pencil shaped designs and optimized analytically. Moreover, general expressions for optimum local thickness and thermal resistance of the links with variable cross section in an arbitrary network are provided. It is shown that improvements up to 50% can be achieved easily by simple geometrical changes if the designer is equipped with a profound knowledge of the important governing parameters. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the resonant nonlinear Schrödinger's equation is studied with three forms of nonlinearity. This equation is also considered with time-dependent coefficients. The first integral method is used to carry out the integration. Exact soliton solutions of this equation are found. These solutions are constructed through the established first integrals. The power of this manageable method is confirmed. [Copyright &y& Elsevier]

Highlights: [•] The production yield was estimated for 98,100,natMo(p,x)99mTc nuclear reactions. [•] MCNPX was used to calculate the proton energy distribution and secondary neutron flux. [•] The residual nuclei during the reactions were monitored as an alternative method. [•] Good agreement was obtained between experimental, theoretical and simulation-based yields. [Copyright &y& Elsevier]

Abstract: In this paper, we study a variety of Boussinesq-like equations. The first integral method is applied to obtain exact 1-soliton solutions for each equation. Exact 1-soliton solutions of these equations are found. [Copyright &y& Elsevier]

This paper studies a couple of fractional nonlinear evolution equations using first integral method. These evolution equations are foam drainage equation and Klein-Gordon equation (KGE), the latter of which is considered in (2 + 1) dimensions. For the fractional evolution, the Jumarie's modified Riemann-Liouville derivative is considered. Exact solutions to these equations are obtained. [ABSTRACT FROM AUTHOR]