Search results for " steady state"
showing 8 items of 8 documents
Soil organic carbon stocks under recommended management practices in different soils of semiarid vineyards
2019
The Intergovernmental Panel on Climate Change (IPCC) approach is widely used to estimate the C account through the use of standardized coefficients that are not site specific. For these reasons, the aim of the work was to define specific IPCC coefficient taking into account differences in pedological characteristics that affect soil C steady state. In a vineyard area of Sicily, the effectiveness of 5 years of recommended management practice (RMP) adoption on soil organic carbon (SOC) stock increases was evaluated by considering 100 paired sites distributed over four functional soil groups. Each site consisted of two neighbouring plots. The soil of one plot was managed with cover crops accor…
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…
Phytoplankton equilibrium phases during thermal stratification in a deep subtropical reservoir
2008
SUMMARY 1. Equilibrium and non-equilibrium hypotheses have often been used to explain observations in community ecology. Published case studies have demonstrated that steady state phytoplankton assemblages are more likely to occur in deep lakes than in shallow mixed ones. 2. Phytoplankton seasonal succession was studied by weekly sampling in Faxinal Reservoir (S Brazil), a subtropical deep, clear, warm monomictic and slightly eutrophic reservoir. This study demonstrated an alternation of steady and non-steady state phases of phytoplankton assemblages with different dominant species during the steady states. 3. During the studied period, three steady states were identified with different dom…
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.
Some diffusion equations with finite propagation speed
2007
We summarize some of our recent results on diffusion equations with finite speed of propagation. These equations have been introduced to correct the infinite speed of propagation predicted by the classical linear diffusion theory. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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.
Diffusion Equations with Finite Speed of Propagation
2007
In this paper we summarize some of our recent results on diffusion equations with finite speed of propagation. These equations have been introduced to correct the infinite speed of propagation predicted by the classical linear diffusion theory.
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.