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We observe that a sustained positivity (or negativity) of a system's second-order response will result in a directional change of the system's characteristics under the corresponding random exposure. We identify these changes with improvement (or decline) in the state of a system and introduce the concept of self-improving systems as systems which characteristics can sustainably improve under a random exposure. The resulting framework is of a general phenomenological nature and can be applied to complex systems across different areas of knowledge. [ABSTRACT FROM AUTHOR]

The optical properties of a periodic slit-groove array perforated in a metal film have been studied experimentally and theoretically. Due to the interplay between periodic slits and periodic grooves, a switching from transmission minimum to maximum and the appearance of an additional dip were experimentally observed. To understand the effect, two different theoretical methods, i.e., the phenomenological method and analytical (coupled-mode) method, for studying the peculiar optical properties have been adopted. The results may provide us with new insights into underlying physics of interaction between the sub-wavelength objects and electromagnetic waves. [ABSTRACT FROM AUTHOR]

An implementation of the full explicitly correlated coupled-cluster singles and doubles model CCSD-F12 using a single Slater-type geminal has been obtained with the aid of automated term generation and evaluation techniques. In contrast to a previously reported computer code [T. Shiozaki et al., J. Chem. Phys. 129, 071101 (2008)], our implementation features a reduced dependence on the auxiliary basis set due to the use of a reformulated evaluation of the so-called Z-intermediate rather than straight forward insertion of an auxiliary basis expansion, which allows an unambiguous comparison to more approximate CCSD-F12 models. First benchmark results for total correlation energies and reaction energies indicate an excellent performance of the much cheaper CCSD(F12) model. [ABSTRACT FROM AUTHOR]

Investigates closely related issues regarding potential practical implementation of condensed phase control schemes. Laser control of reactions in solution; Assumption that the laser will not couple to the condensed phase environment; Effect of uncertainty introduced into the controlling pulse; Challenges facing attempts at condensed phase chemical reaction control.

We study, in this paper, a stochastic version of a coupled Allen–Cahn–Navier–Stokes model in a two-dimensional (2D) bounded domain. The model consists of the Navier–Stokes equations (NSEs) for the velocity, coupled with a Allen–Cahn model for the order (phase) parameter. We prove the existence and the uniqueness of a variational solution. [ABSTRACT FROM AUTHOR]

Abstract The three-dimensional (3D) numerical modelling of laminated glass (LG) plate subjected to coupled thermomechanical loading is in the scope of this paper. The method called FEM23 is applied, in which a 2D in-plane mesh is used, however full 3D results are obtained. In any LG plate glass panes are bonded by very thin polymer films. This layered structure consists of subsequent thick and thin layers of glass and polymer, respectively. Additionally, the thermal and mechanical properties of the glass and the bonding polymer are significantly different. FEM23 is suitable for analyses of such kind of structure. The full 3D results of the coupled problem are obtained following special FEM23 postprocessing. FEM23 is a relatively simple, robust and effective method and 3D thermo-mechanical results obtained are correct for both stationary and non-stationary heat transport. The accuracy of the method has been examined with the use of solutions obtained from the ABAQUS system. The examples presented in the article include two-, three- and four-paned LG plates. [ABSTRACT FROM AUTHOR]

Highlights • Analytical formulation of bridge-pedestrian interaction including inter-variability. • A new SDOF pedestrian model reproduces the human gait and transmits contact forces only through compliant and damped legs. • Finite element method adopted to model the 3D geometry of the bridge. • Bridge-pedestrian coupled equations of motion integrated through an iterative procedure. • Loading scenarios include groups of pedestrians with different spatial distributions. Abstract In this work, an analytical formulation for the vibration response of a bridge due to walking pedestrians is proposed to the aim of modelling the human-structure interaction (HSI) in the vertical direction. Bridge and pedestrians are described as mechanical systems having a finite number of degrees of freedom (DOFs). A new single DOF model of a bipedal pedestrian is proposed, that reproduces the alternation of single and double support phases of human gait and the related ground reaction forces. The finite element method is adopted to model the 3D geometry of the bridge. The coupled equations of motion are derived based on the key assumption that contact points between the pedestrians and the bridge deck are massless. However, the structural matrices of the coupled system are time varying due to the pedestrian motion along the bridge. An uncoupled solution strategy is devised to reduce the computational burden, allowing for the separate integration of the bridge and the pedestrian sub-systems. The coupled formulation is uncoupled and associated with an iterative procedure that restores compatibility and equilibrium at contact points. The pedestrian model and the analytical procedure are implemented in a research code where input data are the bridge structural matrices computed with a commercial FE code. The modelling and analysis procedure is applied to a case study, a lively footbridge in Seriate, Italy. A first validation of the code is obtained by comparison with a closed form solution for a 1D beam. For the loading scenarios analyzed here, a maximum of two iterations per step are necessary to achieve convergence within a prescribed tolerance. Loading scenarios encompassing groups of pedestrians in different transverse positions highlight the importance of the 3D bridge modelling. The comparison with a few experimental results clarifies the role of the modelling assumptions. Conclusions discuss novelties, advantages, limits and future developments of the proposed approach. [ABSTRACT FROM AUTHOR]

Highlights • A mechanism to evaluate the MS's vulnerability under threats is proposed. • The indices of topological structure vulnerability and the functional vulnerability are given. • The multidimensional spatial computing model of vulnerability is build. Abstract The safe operation requirement for an enterprise depends significantly on the uninterrupted and reliable functioning of its manufacturing system (MS). However, this system is frequently subjected to different disturbances and destructions, such as safety accidents, equipment fault, and misoperation. Therefore, a sophisticated evaluation mechanism and an effective alleviation design for the vulnerability of a MS are of great importance for the reliable functioning of the MS. This study proposes a detailed methodology to comprehensively assess the vulnerability of a MS subject to different disturbances by using complex networks and simulation technology. The proposed methodology includes a complex network expression for the MS, a description of the equipment failure scenarios, a method to analyze the vulnerability of the MS, and an evaluation method to quantify the vulnerability value. The vulnerability of a MS is evaluated in terms of its work, including the topological structure vulnerability and function vulnerability. Different vulnerability metrics are described, and the vulnerability information is quantified by the multidimensional spatial computing method. Subsequently, the effectiveness of the proposed method is validated in the engineering assembly manufacturing system (EAMS). [ABSTRACT FROM AUTHOR]

The formal theory is presented for calculating the analytic first derivative of the energy with respect to arbitrary perturbations within the equation-of-motion coupled-cluster (EOM-CC) approximation. Through use of the Dalgarno–Stewart interchange theorem (Z-vector method), terms involving derivatives of the ground state cluster amplitudes are eliminated, leading to the definition of a new quasiparticle de-excitation operator which simplifies the theory and significantly reduces the expected cost associated with studying potential energy surfaces for excited electronic states. For both illustrative and pragmatic reasons, the final equations are cast in a form similar to that developed for ground state CC energy derivatives, involving contraction of effective one- and two-particle density matrices with matrix elements of the differentiated Hamiltonian. Some aspects regarding calculation of the gradient are discussed with particular attention devoted to similarities between the structure of the present formulas and those which have been previously implemented for the ground state problem. [ABSTRACT FROM AUTHOR]

Abstract: The problem of stable equilibrium of a Bernoulli-Euler beam with both ends fixed positioned in an electrostatic field under the action of a pulse laser is considered. The initial equilibrium position under the action of the electrostatic field has been obtained. It has been shown that there exist either two equilibrium positions of this kind—stable and unstable ones—or none in a sufficiently strong electric field. The temperature field in the beam under the action of a laser pulse has been found. The possibility to lose the stability of equilibrium under heating of the element by a laser pulse is suggested for the first time. Regions corresponding to the stability of the aforesaid equilibrium position in the space of pulse parameters have been determined. [ABSTRACT FROM AUTHOR]

The semi-analytical transient solutions of fully thermomechanical coupling for sliding contact have been deduced by using the plane-point heat source equivalent method, the thermoelastic displacement potential and the central difference method. To improve the calculated efficiency, the discrete convolution and fast Fourier transform are applied. The effects of coupled term, sliding velocity, frictional coefficient and initial temperature on temperature rise and the influence of thermal behavior on stress are studied. Results indicate that the coupled term can significantly affect the temperature rise for high velocity and it can be ignored for low velocity; the temperature rise is sensitive to the sliding velocity and the frictional coefficient; the Mises stress on the contact patch is decreased when considering thermal effect. [ABSTRACT FROM AUTHOR]

In this paper, we study, from the numerical point of view, a porous thermoviscoelastic mixture problem. The mechanical problem is written as a linear coupled system of two hyperbolic partial differential equations for the porosities and a parabolic partial differential equation for the temperature field. An existence and uniqueness result and an energy decay property are stated. Then, fully discrete approximations are introduced by using the finite element method to approximate the spatial variable and the backward Euler scheme to discretize the time derivatives. A priori error estimates are proved from which, under suitable regularity conditions, the linear convergence of the algorithm is derived. Finally, some numerical simulations are presented to demonstrate the accuracy of the approximations in an academical one-dimensional example and the behaviour of the solutions in one- and two-dimensional problems. [ABSTRACT FROM AUTHOR]

The electrostatically controlled deployable membrane antenna (ECDMA) is a promising space structure due to its low weight, large aperture and high precision characteristics. However, it is an extreme challenge to describe the coupled field between electrostatic and membrane structure accurately. A direct coupled method is applied to solve the coupled problem in this paper. Firstly, the membrane structure and electrostatic field are uniformly described by energy, considering the coupled problem is an energy conservation phenomenon. Then the direct coupled electrostatic-structural field governing equilibrium equations are obtained by energy variation approach. Numerical results show that the direct coupled method improves the computing efficiency by 36% compared with the traditional indirect coupled method with the same level accuracy. Finally, the prototype has been manufactured and tested and the ECDMA finite element simulations show good agreement with the experiment results as the maximum surface error difference is 6%. [ABSTRACT FROM AUTHOR]

The dynamic response of a two-dimensional generalized thermal shock problem is investigated in the context of the fractional order theory of thermoelasticity proposed by Sherief et al. To demonstrate the solution process, a thermoelastic half-space subjected to a thermal shock on its bounding surface is considered in detail. The governing equations for the problem are formulated and then solved by normal mode analysis. The distributions of the considered nondimensional temperature, displacement, and stress are obtained and illustrated graphically. The effect of fractional order parameter on the variations of the considered variables is investigated, and the results show that the fractional order parameter has significant influence on the variations of the considered variables. [ABSTRACT FROM AUTHOR]

Piezoelectric and flexoelectric nanostructures attracted great interest from different research communities for their potential applications as sensors, actuators and energy harvesters. Nevertheless, modeling and analysis of such structures are still under investigation. In fact, strain gradient effects are expected to be nonnegligible at the nanoscale level where they induce substantial variations on the static and dynamic responses of the nanostructure, especially when coupled field behavior are present. Therefore, flexoelectricity which refers to the electromechanical coupling between electrical polarization and mechanical strain gradient, is expected to be dominant at the nanoscale. In this paper, the main focus is to analyze analytically the static and dynamic responses of nanobeams, having different boundary conditions and electrical loads, where gradient elasticity, piezoelectricity and flexoelectricity are taken into account. We develop a complete mathematical model using Hamilton’s principle. The derived governing electromechanical coupled equations and corresponding boundary conditions are solved using a Galerkin procedure based on an assumed mode approach. The principal electromechanical outputs are calculated analytically for actuation and energy harvesting configurations. Bidirectional polarization, electric field and elastic strain gradient effect are taken into account in the developed model. Validation and comparison with previously published results showed that considerable decrease of the performance could be observed because of the introduction of the elastic strain gradient effect. The performance degradation is also more pronounced if the aspect ratio is reduced. [ABSTRACT FROM AUTHOR]

On the basis of a general integral form of the variational principle of the least possible dissipation of energy of the nonequilibrium thermodynamics, we deduce a nonclassical nonsteady heat-conduction equation for multilayer polyreinforced shells of any shape. A method for the determination of the integral heat conductivities of reinforced layers is developed and the effective constitutive equations for the description of its thermoelastic behavior are proposed. A nonclassical model of deformation of the multilayer shell and a nonlinear model of distribution of the heat flux along the thickness of the layer are formulated. This allows us to take into account the transverse shear strains and guarantee the conditions of thermomechanical contact of the layers and the conditions of thermomechanical loading on the face surfaces of the shell. We construct a closed system of differential equations with the corresponding initial and boundary conditions for a coupled problem of thermoelastic deformation of layered composite shells and plates. [ABSTRACT FROM AUTHOR]

We present a brief survey of investigations carried out in recent years by the Lviv scientific school of the mechanics of coupled fields on the problems of construction and generalization of mathematical models and methods aimed at the description, determination, and optimization of the thermomechanical behavior of bodies under the combined action of force, thermal, and electromagnetic loads. [ABSTRACT FROM AUTHOR]

Numerical model of combined laser and induction welding is presented and solved. From the physical viewpoint, the process represents a coupled problem of nonlinear and nonstationary interaction of the magnetic and temperature fields respecting the phase change and evaporation of heated molten metal (keyhole effect). A specific algorithm was developed for manipulation with the space and time variation of interface between solid and molten metal. Selected results are compared with the realized experiment. [ABSTRACT FROM AUTHOR]

This article presents a possible inflation scenario as a consequence of non-minimal gravitational couplings in the Conformal Standard Model. The model consists, in comparison to the SM, of additional right-chiral neutrinos and complex scalars coupled to the right-chiral neutrinos but not to the SM particles. The inflation is driven by two non-minimally coupled fields, one being the usual Higgs and the other one of the sterile scalars. It turns out that in this model, the tensor-to-scalar ratio and spectral index can match the current data for a wide range of parameters. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present an original study for optimizing the size of the longitudinal-flux double-sided linear switched reluctance motor (LSRM) under thermal and weight constraints. The performance is evaluated taken into account duty cycle operating conditions and thermal restrictions. The proposed approach couples finite element analysis for magnetic propulsion force computation and lumped-parameter thermal network for thermal transient analysis. The LSRMs design parameters are characterized by the number of phases and by their size denoted by the pole stroke. The operating conditions are the current density, the duty cycle and the admissible temperature rise of the insulation system. The grid search algorithm is used for solving the optimization problem. From the results, with the help of a novel multivariable optimization chart, a set of optimal configurations regarding to miniaturizations and downsizing of LSRMs is provided. [ABSTRACT FROM PUBLISHER]

In this paper, the influence of gap consideration on load identification under various Halbach-array-based topologies (HABOs) is investigated while the system is on-duty. The load characteristics of a radial flux generator with closed-slots and the exterior rotor topology is discussed, where the effect of eddy-currents are observed. This comparative study deals with the consideration of the combined moment of inertia calculation that demonstrates how electromagnetic-based post processing calculations are estimated without the aid of nominal machine parameter values. The analysis was performed using a 2-D finite-element simulation of different HABOs with the gap consideration between the segments. Additionally, a comprehensive comparison with no gap is considered. Also, the dynamic analysis using an uncontrolled conventional rectifier model is used to derive effected key output parameters such as torque, output power, power factor, and line-to-line voltage. The major objective of the study is to determine corresponding load results in order to employ the most suitable and capable magnetization topology from the load perspective in the PM synchronous generator (PMSGs). Accordingly, the maximum power (MP) point was carried out to maximize the output DC power. With respect to the combined moment of inertia estimation, the load parameter estimation is verified experimentally on a surface-mounted PMSG using different magnetization topologies. Furthermore, commercial and environmental issues of the project are considered to reduce CO 2 emissions as part of green power generation development. [ABSTRACT FROM AUTHOR]

We analyze a weak formulation of the coupled problem defining the interaction between a free fluid and a poroelastic structure. The problem is governed by the time-dependent incompressible Navier–Stokes equations and the Biot equations. Under a small data assumption, existence and uniqueness results are proved and a priori estimates are provided. [ABSTRACT FROM AUTHOR]

Anomaly matching constrains low-energy physics of strongly-coupled field theories, but it is not useful at finite temperature due to contamination from high-energy states. The known exception is an 't Hooft anomaly involving one-form symmetries as in pure SU( N ) Yang-Mills theory at θ = π. Recent development about large- N volume independence, however, gives us a circumstantial evidence that 't Hooft anomalies can also remain under circle compactifications in some theories without one-form symmetries. We develop a systematic procedure for deriving an 't Hooft anomaly of the circle-compactified theory starting from the anomaly of the original uncompactified theory without one-form symmetries, where the twisted boundary condition for the compactified direction plays a pivotal role. As an application, we consider $$ {\mathbb{Z}}_N $$ -twisted $$ \mathbb{C}{P}^{N-1} $$ sigma model and massless $$ {\mathbb{Z}}_N $$ -QCD, and compute their anomalies explicitly. [ABSTRACT FROM AUTHOR]

Liquid loading is a major operational constraint in mature gas fields around the world. It manifests itself as an increasing back pressure on the reservoir due to a rising liquid column in the well, which initially decreases deliverability, then ultimately causes the gas well to cease production. Theoretically, every gas well will experience this debilitating phenomenon in the latter stages of its producing life. In this paper, both laboratory experiments and numerical simulations are presented to shed more light on the physical process of liquid loading, with a focus on reservoir responses. On the one hand, core-flooding experimental setups of different scales were designed and constructed to investigate back pressure effects on transient flow through the near-wellbore region of the reservoir. On the other hand, the modelling of a gas well undergoing controlled flow and shut-in cycles was performed to validate core-scale observations at reservoir scale, using commercial integrated numerical software that connects a transient wellbore model to a transient reservoir model. The simulated transient characteristics of short-term downhole dynamics (e.g. liquid re-injection and co-current/counter-current flows) supported the U-shaped concept observed in the experiments. The detected temporal distribution of pore fluid pressure within the reservoir medium itself (referred to as the U-shaped pressure profile) was observed both experimentally at the core-scale and numerically at the reservoir-scale. This pressure distribution can be used to explain re-injection of the denser phases into the near-wellbore region of the reservoir. [ABSTRACT FROM AUTHOR]

This paper presents an a posteriori error analysis for the stationary Stokes-Darcy coupled problem approximated by finite element methods on anisotropic meshes in [ABSTRACT FROM AUTHOR]

This paper presents a solution procedure based on the finite element method for the three-constituent coupled problem representing the behavior of unsaturated porous media. A formulation is derived from the theory of porous media considering the dynamic behavior, the balance of momenta of porous liquid, porous gas, and solid porous matrix. The hysteresis of the liquid retention behavior is also modeled. A retention model able to smoothly represent the transition from maximum saturation to partially saturated states, and vice versa, is considered. With these features, the resulting system of equations is fairly complex; however an efficient, stable, and accurate numerical method is developed for its solution. The derivation of consistent tangent operators of first and second order to obtain quadratic convergence is presented in addition to all details to properly implement the numerical solver, e.g., consistent treatment of initial conditions. Finally, a number of numerical experiments are studied in order to illustrate the model capabilities in particular with regard to the influence of gas pressure on the unsaturated porous media behavior. [ABSTRACT FROM AUTHOR]

In this paper, an efficient and robust numerical method is proposed to solve non-symmetric eigenvalue problems resulting from the spatial discretization with the finite element method of a vibroacoustic interior problem. The proposed method relies on a perturbation method. Finding the eigenvalues consists in determining zero values of a scalar that depends on angular frequency. Numerical tests show that the proposed method is not sensitive to poorly conditioned matrices resulting from the displacement–pressure formulation. Moreover, the computational times required with this method are lower than those needed with a classical technique such as, for example, the Arnoldi method. [ABSTRACT FROM AUTHOR]

We study the control of quantum interference in a four-level atom driven by three coherent fields forming a closed loop. The spontaneous emission spectrum shows two sets of peaks which are dramatically influenced by the fields. Due to destructive quantum interference, a dark line can be observed in the emission spectrum, and the condition of the dark line is given. We found that the conversion between destructive and constructive quantum interference can be achieved through controlling the Rabi frequency of the external fields. [ABSTRACT FROM AUTHOR]

In the nearly 20 years that have elapsed since its discovery, the gauge-gravity correspondence has become established as an efficient tool to explore the physics of a large class of strongly-coupled field theories. A brief overview is given here of its formulation and a few of its applications, emphasizing attempts to emulate aspects of the strong-coupling regime of quantum chromodynamics (QCD). To the extent possible, the presentation is self-contained, and does not presuppose knowledge of string theory. [ABSTRACT FROM AUTHOR]

In this paper, we propose and evaluate the performance of a unified computational framework for preconditioning systems of linear equations resulting from the solution of coupled problems with monolithic schemes. The framework is composed by promising application-specific preconditioners presented previously in the literature with the common feature that they are able to be implemented for a generic coupled problem, involving an arbitrary number of fields, and to be used to solve a variety of applications. The first selected preconditioner is based on a generic block Gauss–Seidel iteration for uncoupling the fields, and standard algebraic multigrid (AMG) methods for solving the resulting uncoupled problems. The second preconditioner is based on the semi-implicit method for pressure-linked equations (SIMPLE) which is extended here to deal with an arbitrary number of fields, and also results in uncoupled problems that can be solved with standard AMG. Finally, a more sophisticated preconditioner is considered which enforces the coupling at all AMG levels, in contrast to the other two techniques which resolve the coupling only at the finest level. Our purpose is to show that these methods perform satisfactory in quite different scenarios apart from their original applications. To this end, we consider three very different coupled problems: thermo-structure interaction, fluid–structure interaction and a complex model of the human lung. Numerical results show that these general purpose methods are efficient and scalable in this range of applications. [ABSTRACT FROM AUTHOR]

Abstract In a recent paper referred to in the title, the author investigated a (2+1)-dimensional Zakharov–Kuznetsov (ZK) equation and claimed that with the aid of the coupled Burgers' equations, a new multi-soliton solution were formally generated. We argue that the generated N-soliton solutions in the case of N ≥ 2 is incorrect and is not admitted by the original (2+1)-dimensional ZK equation. [ABSTRACT FROM AUTHOR]

Focuses on a study which analyzed high-frequency coupled electromagnetic field problems using the magnetic vector potential finite element method. Description of the computer programs used; Features of the boundary conditions that were presented; Comparison of the calculated resonant frequencies with the classical theory for reflected waves; Observation from the absorbing finite elements.

The conventional Timoshenko piezoelectric beam finite elements based on First-order Shear Deformation Theory (FSDT) do not maintain the accuracy and convergence consistently over the applicable range of material and geometric properties. In these elements, the inaccuracy arises due to the induced potential effects in the transverse direction and inefficiency arises due to the use of independently assumed linear polynomial interpolation of the field variables in the longitudinal direction. In this work, a novel FSDT-based piezoelectric beam finite element is proposed which is devoid of these deficiencies. A variational formulation with consistent through-thickness potential is developed. The governing equilibrium equations are used to derive the coupled field relations. These relations are used to develop a polynomial interpolation scheme which properly accommodates the bending-extension, bending-shear and induced potential couplings to produce accurate results in an efficient manner. It is noteworthy that this consistently accurate and efficient beam finite element uses the same nodal variables as of conventional FSDT formulations available in the literature. Comparison of numerical results proves the consistent accuracy and efficiency of the proposed formulation irrespective of geometric and material configurations, unlike the conventional formulations. [ABSTRACT FROM AUTHOR]

Depending on the maximum amplitude of externally applied cyclic electric fields, ferroelectric ceramics show minor or major hysteresis. The materials also show asymmetric butterfly hysteresis in a prepoled material. Aiming at capturing these behaviour in a phenomenological constitutive model, a multi-surface modelling approach for ferroelectrics is introduced. In this paper, with the note on the motivation for a multi-surface model related to the results of new experimental investigations and also to experimental data reported in the literature, the constitutive relation for a rate dependent multi-surface ferroelectric model is developed. Following this, a brief graphical illustration shows how this model captures the objective phenomena. Consequently, the numerical implementation of the model to capture experimental results is demonstrated. Finally, the performance of this model to represent behaviour of decaying polarisation offset of electrically fatigued specimen is shown. [ABSTRACT FROM AUTHOR]

This paper focuses on the existence of periodic solutions for coupled systems on networks with time-delay and linear coupling (CSNDLC). Based on graph theory, coincidence degree theory and the Lyapunov method, a systematic approach for the existence of periodic solutions to CSNDLC is developed. And this approach is applied to the linear coupled oscillators with time-delay on a network. In addition, global asymptotic stability criterion for its periodic solution is obtained. Finally, a numerical example is provided to illustrate the effectiveness of the results developed. [ABSTRACT FROM AUTHOR]

The purpose of this brief paper is to present a new derivation of Biot 's theory of linear poroelasticity (Biot, M., 1935, "Le Probleme de la Consolidation des Matieres Argileuses Sous une Charge," Ann. Soc. Sci. Bruxelles, B55, pp. 110-113; Biot, M., 1941, "General Theory of Three-Dimensional Consolidation," J. Appl. Phys., 12, pp. 155-164; and Biot, M., and Willis, D., 1957, "The Elastic Coefficients of the Theory of Consolidation," J. Appl. Mech., 24, pp. 594-601) in a modern thermodynamically consistent fashion, and show that it may be deduced as a special case of a more general theory of chemoelasticity. [ABSTRACT FROM AUTHOR]

Numerical solutions of non-linear stochastic thermo-hyperelastic problems at finite strains are addressed. These belong to a category of non-linear coupled problems that impose challenges on their numerical treatment both in the physical and stochastic spaces. Combining the high order finite element methods (FEMs) for discretizing the physical space and the polynomial chaos projection (PCP) method for discretizing the stochastic space, a non-intrusive scheme is obtained manifesting an exponential convergence rate. The method is applied to a 1-D coupled, stationary, thermo-hyperelastic system with stochastic material properties. We derive exact stochastic solutions that serve for comparison to numerical results, allowing their verification. These demonstrate that stochastic coupled-problems intractable by standard Monte-Carlo (MC) methods may be easily computed by combining high-order FEMs with the PCP method controlling discretization errors. [ABSTRACT FROM AUTHOR]

El articulo discute sobre el sistema complejos y física estadística con el enfoque de en la ciudad de Estocolmo y Habana. El articulo también discute sobre las sistemas complejos publica importantes artículos sobre micro-gotas en emulsiones de combustible, el impacto negativo del sistema complejos en el desarrollo de la industria electrónica nacional y dinámica de avalanchas en vórtices superconductores y pilas.

Mathematical modeling of evolutionary states of non-homogeneous multi-layer shallow shells with orthotropic initial imperfections belongs to one of the most important and necessary steps while constructing numerous technical devices, as well as aviation and ship structural members. In first part of the paper fundamental hypotheses are formulated which allow us to derive Hamilton–Ostrogradsky equations. The latter yield equations governing shell behavior within the applied hypotheses and modified Pelekh–Sheremetev conditions. The aim of second part of the paper is to formulate fundamental hypotheses in order to construct coupled boundary problems of thermo-elasticity which are used in non-classical mathematical models for multi-layer shallow shells with initial imperfections. In addition, a coupled problem for multi-layer shell taking into account a 3D heat transfer equation is formulated. Third part of the paper introduces necessary phase spaces for the second boundary value problem for evolutionary equations, defining the coupled problem of thermo-elasticity for a simply supported shallow shell. The theorem regarding uniqueness of the mentioned boundary value problem is proved. It is also proved that the approximate solution regarding the second boundary value problem defining condition for the thermo-mechanical evolution for rectangular shallow homogeneous and isotropic shells can be found using the Bubnov–Galerkin method. [ABSTRACT FROM AUTHOR]

Modern systems are mostly coupled together. Therefore, they should be modeled as interdependent networks. In this paper, the robustness of interdependent networks coupled with different type networks is studied in detail under both targeted and random attack. The critical fraction of nodes leading to a complete fragmentation of two interdependent networks is analyzed. Some findings are summarized as: (i) For random attack problem, the existence criteria for the giant component in interdependent networks coupled by two different type networks are quite different from those coupled by the same type networks. Different type coupled networks are more vulnerable than the same type coupled-networks. (ii) For targeted attack problem, if the highly connected nodes are protected and only the lowly connected nodes failed, the system leads to a first order percolation phase transition for different type coupled-networks, and a second transition for same type coupled-networks as well. The available result implies that different type coupled-networks are difficult to defend by strategies such as protecting the high degree nodes that can be useful to significantly improve robustness of the same type coupled-networks. (iii) For targeted attack problem, when the lowly connected nodes are protected and only the highly connected nodes failed, coupled scale free networks become more vulnerable than the others. [ABSTRACT FROM AUTHOR]

In this paper we study invariant domains with unbounded dynamics for one cosmological Hamiltonian system which is formed by the conformally coupled field; this system was introduced by Maciejewski et al. (2007). We find a few groups of conditions imposed on parameters of this system for which all trajectories are unbounded in both of time directions. Further, we present a few groups of other conditions imposed on system parameters under which we localize the invariant domain with unbounded dynamics; this domain is defined with help of bounds for values of the Hamiltonian level surface parameter. We describe one group of conditions when our system possesses two periodic orbits found explicitly. In some of rest cases we get localization bounds for compact invariant sets. [ABSTRACT FROM AUTHOR]

We consider a system of an evolutionary variational inequality of two obstacles type, depending on the temperature, coupled with the heat equation. We prove existence of solution of this system and we present examples that motivated this work. In particular, with additional assumptions on the data, we prove that solutions of this problem are also solutions of a similar problem where the convex set is of gradient constraint type (that depends on the temperature), improving a previous result. [ABSTRACT FROM AUTHOR]

We review coupled SU(3)-structures, also known in the literature as restricted half-flat structures, in relation to supersymmetry. In particular, we study special classes of examples admitting such structures and the behavior of flows of SU(3)-structures with respect to the coupled condition. [ABSTRACT FROM AUTHOR]

Summary Field studies of subsurface transport of colloids, which may act as carriers of contaminants, are still rare. This is particularly true for heterogeneous and fractured matrices. To address this knowledge gap, a 30-m long monitoring trench was constructed at the lower end of sloping farmland in central Sichuan, southwest China. During the summer of 2013, high resolution dynamic and temporal fracture flow discharging from the interface between fractured mudrock and impermeable sandstone was obtained at intervals of 5 min (for fast rising stages), 30–60 min (for slow falling stages) or 15 min (at all other times). This discharge was analyzed to elucidate fracture flow and colloid transport in response to rainfall events. Colloid concentrations were observed to increase quickly once rainfall started (∼15–90 min) and reached peak values of up to 188 mg/L. Interestingly, maximum colloid concentration occurred prior to the arrival of flow discharge peak (i.e. maximum colloid concentration was observed before saturation of the soil layer). Rainfall intensity (rather than its duration) was noted to be the main factor controlling colloid response and transport. Dissolved organic carbon concentration and δ 18 O dynamics in combination with soil water potential were used to apportion water sources of fracture flow at different stages. These approaches suggested the main source of the colloids discharged to be associated with the flushing of colloids from the soil mesopores and macropores. Beyond the scientific interest of colloid mobilization and transport at the field scale, these results have important implications for a region of about 160,000 km 2 in southwest China that featured similar hydrogeologic settings as the experimental site. In this agriculture-dominated area, application of pesticides and fertilizers to farmland is prevalent. These results highlight the need to avoid such applications immediately before rainfall events in order to reduce rapid migration to groundwater via fracture flow in either dissolved form or in association with colloids. [ABSTRACT FROM AUTHOR]

In the paper, a benchmark in the field of induction heating is described in order to test optimization methods. The optimal design of a pancake inductor for the controlled heating of a graphite disk is considered. The direct problem is characterized by a coupledmagneto-thermal field analysis. [ABSTRACT FROM AUTHOR]

Connections are ubiquitous. The hydrologic cycle is perhaps the best example: every component of this cycle is connected to every other component, but some connections are stronger than the others. Unraveling the nature and extent of connections in hydrologic systems, as well as their interactions with others, has always been a fundamental challenge in hydrology. Despite the progress in this direction, a strong scientific theory that is suitable for studying all types of connections in hydrology continues to be elusive. In this article, I argue that the theory of networks provides a generic theory for studying all types of connections in hydrology. After presenting a general discussion of complex systems as networks, I offer a brief account of the history of development of network theory and some basic concepts and measures of complex networks, and explain the relevance of complex network theory for hydrologic systems, with three specific examples. [ABSTRACT FROM AUTHOR]

With the aim of providing an effective method for optimal design and condition monitoring of the plug-in connector used in gas-insulated switchgears, a 3-D coupled field finite-element method model has been developed for analyzing the electrical, thermal, and mechanical behaviors of a plug-in connector under steady and short circuit conditions. Contact resistance and electromagnetic repulsion force are considered by modeling an equivalent contact bridge between contact interfaces. Electromagnetic force and temperature derived from electromagnetic-thermal coupled field calculation are used as the load inputs in thermal-mechanical coupled field analysis. The validity of the calculation model is demonstrated by temperature rise experiments and comparing with other closed formulas. Dynamic behaviors of a plug-in connector under short circuit conditions have been also analyzed. [ABSTRACT FROM AUTHOR]