Search results for "steady states"

showing 5 items of 5 documents

A generalized Degn–Harrison reaction–diffusion system: Asymptotic stability and non-existence results

2021

Abstract In this paper we study the Degn–Harrison system with a generalized reaction term. Once proved the global existence and boundedness of a unique solution, we address the asymptotic behavior of the system. The conditions for the global asymptotic stability of the steady state solution are derived using the appropriate techniques based on the eigen-analysis, the Poincare–Bendixson theorem and the direct Lyapunov method. Numerical simulations are also shown to corroborate the asymptotic stability predictions. Moreover, we determine the constraints on the size of the reactor and the diffusion coefficient such that the system does not admit non-constant positive steady state solutions.

Lyapunov functionSteady state (electronics)Asymptotic stability Existence of solutions Generalized Degn–Harrison system Non-constant steady state solutions Steady statesApplied Mathematics010102 general mathematicsGeneral EngineeringGeneral Medicine01 natural sciencesTerm (time)010101 applied mathematicsComputational Mathematicssymbols.namesakeExponential stabilityReaction–diffusion systemsymbolsApplied mathematics0101 mathematicsDiffusion (business)General Economics Econometrics and FinanceSettore MAT/07 - Fisica MatematicaAnalysisMathematics
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World Interest Rates and Inequality: Insight from the Galor - Zeira Model

2018

In this paper, we study the relationship between changes in the world interest rate and within-country inequality during the 1985–2005 period in which the world interest rate sharply declined. In line with the predictions of the seminal model of Galor and Zeira [Income distribution and macroeconomics. Review of Economic Studies 60, 35–52], the analysis suggests that the decrease in the world interest rate is associated with a decrease in inequality in poor countries and an increase in inequality in rich ones.

Economics and EconometricsInequalitymedia_common.quotation_subjectKeynesian economics05 social sciencesInterest rateGalor-Zeira modelInequalityIncome distributionWorld interest rates0502 economics and businessEconomics050207 economicsSettore SECS-P/01 - Economia PoliticaMultiple steady statesInequality Economic Growth Multiple Steady States World Interest RatesEconomic growth050205 econometrics media_common
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Adaptive discontinuous evolution Galerkin method for dry atmospheric flow

2014

We present a new adaptive genuinely multidimensional method within the framework of the discontinuous Galerkin method. The discontinuous evolution Galerkin (DEG) method couples a discontinuous Galerkin formulation with approximate evolution operators. The latter are constructed using the bicharacteristics of multidimensional hyperbolic systems, such that all of the infinitely many directions of wave propagation are considered explicitly. In order to take into account multiscale phenomena that typically appear in atmospheric flows nonlinear fluxes are split into a linear part governing the acoustic and gravitational waves and a nonlinear part that models advection. Time integration is realiz…

Backward differentiation formulasteady statesPhysics and Astronomy (miscellaneous)Wave propagationdry atmospheric convectionlarge time stepsystems of hyperbolic balance lawssymbols.namesakeDiscontinuous Galerkin methodApplied mathematicsevolution Galerkin schemesGalerkin methodMathematicssemi-implicit approximationNumerical AnalysisAdaptive mesh refinementApplied MathematicsEuler equationsRiemann solverComputer Science ApplicationsEuler equationsComputational MathematicsNonlinear systemClassical mechanicsModeling and SimulationsymbolsJournal of Computational Physics
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Buckling and nonlinear dynamics of elastically coupled double-beam systems

2016

Abstract This paper deals with damped transverse vibrations of elastically coupled double-beam system under even compressive axial loading. Each beam is assumed to be elastic, extensible and supported at the ends. The related stationary problem is proved to admit both unimodal (only one eigenfunction is involved) and bimodal (two eigenfunctions are involved) buckled solutions, and their number depends on structural parameters and applied axial loads. The occurrence of a so complex structure of the steady states motivates a global analysis of the longtime dynamics. In this regard, we are able to prove the existence of a global regular attractor of solutions. When a finite set of stationary s…

Buckling; Double-beam system; Global attractor; Nonlinear oscillations; Steady states; Mechanics of Materials; Mechanical Engineering; Applied MathematicsSteady statesBucklingApplied MathematicsMechanical Engineering010102 general mathematicsEigenfunctionDouble-beam system01 natural sciencesGlobal attractorNonlinear oscillations010101 applied mathematicsVibrationNonlinear systemClassical mechanicsBucklingMechanics of MaterialsAttractor0101 mathematicsNonlinear OscillationsFinite setBeam (structure)MathematicsInternational Journal of Non-Linear Mechanics
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Nonlinear Thermal Transport with Inertia in Thin Wires: Thermal Fronts and Steady States

2022

Abstract In a series of papers we have obtained results for nonlinear heat transport when thin wires exchange heat non-linearly with the surroundings, with particular attention to propagating solitons. Here we obtain and discuss new results related to the propagation of nonlinear heat fronts and some conceptual aspects referring to the application of the second principle of thermodynamics to some nonlinear steady states related to non-propagating solitons.

Nonlinear thermal frontsauxiliary equation methodMaxwell-Cattaneo lawGeneral Physics and AstronomyGeneral Chemistrynonlinear steady statesnonlinear radiative transferJournal of Non-Equilibrium Thermodynamics
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