Search results for "libri"

Equilibrium swelling properties of polyampholytic hydrogels

1996

The role of counter ions and ion dissociation in establishing the equilibrium swelling of balanced and unbalanced polyampholytic hydrogels has been investigated experimentally and theoretically. The swelling dependence on both the net charge offset and the external bath salt concentration has been examined using an acrylamide based polyampholytic hydrogels. By careful consideration of the swelling kinetics, we illustrate the effects of ion dissociation equilibria and counter ion shielding in polyampholytic hydrogels near their balance point where both polyelectrolyte and polyampholyte effects are present. The theory considers a Flory type swelling model where the Coulombic interactions betw…

Posturografía estática con pruebas dinámicas. Utilidad de los parámetros biomecánicos en la valoración del paciente vestibular

2012

[ES] Introducción y objetivos: La posturografía permite evaluar el control postural de un sujeto. En este estudio se presentan aquellos parámetros biomecánicos del sistema de posturografía empleado, que han resultado útiles para valorar funcionalmente los pacientes vestibulares de nuestra muestra. Material y métodos: De un total de 89 participantes, 59 eran sujetos sanos y 30 presentaban un trastorno vestibular periférico. Todos ellos realizaron un estudio posturográfico mediante el sistema NedSVE/IBV que combina pruebas estáticas (Romberg) y dinámicas (límites de estabilidad y control rítmico-direccional). Posteriormente se compararon las medidas halladas en uno y otro grupo. Resultados: L…

Recent trends in solar exergy and net radiation at global scale

2012

Abstract The availability during the last decades of remotely sensed images and global climatic data allow us to analyse the “Earth system” as a whole in order to develop concepts for global environmental management. This system can be considered a complex, dissipative, dynamic entity, far from thermodynamic equilibrium ( Schellnhuber, 1999 ). Energy balance has been considered for many decades to understand the functioning of ecosystems, the biosphere or the Earth planet as a whole, but it is also possible to study our planet from a thermodynamic point of view. In this letter we analyse recent trends in solar exergy and net radiation at global scale during the period 1980–2010, distinguish…

A Stackelberg-game approach to support the design of logistic terminals

2014

This paper deals with the design of logistic terminals taking Sicily, in the South of Italy, as a case study. It focuses on consolidation terminals for truckers and addresses the problem of optimising location pattern and public share in investments. This problem is solved through a Stackelberg game between the designer and the collective of road carriers. So a bilevel approach combines a system-optimum problem, at the upper level, with the carrier equilibrium problem, at the lower level. The choice behaviour of the lower-level player is simulated by a random utility model. The output of the game suggests that private companies and society should share the investments and the public contrib…

Attenuation of the Fourth Sound in Liquid Helium II via Extended Thermodymamics

2004

Studies of polyamines transport through liquid membranes with D2EHPA as a carrier.

2008

The transport of polyamines through the liquid membranes with di‐2‐ethylhexyl phosphoric acid (D2EHPA) was investigated. The study was performed in three main steps: liquid–liquid extraction (LLE), bulk liquid membrane (BLM) extraction, and supported liquid membrane (SLM) extraction. Equilibrium distribution experiments allowed determining the extraction constants and stoichiometric coefficients for each polyamine. It turned out that one amino group binds two molecules of carrier (one D2EHPA dimer) and the extractability of polyamine rises with the increase in number of function groups in the molecule. The BLM and SLM experiments showed that despite considerable differences in distribution …

Pecking Order Versus Trade-off: An Empirical Approach to the Small and Medium Enterprise Capital Structure

2003

In this paper, we explore two of the most relevant theories that explain financial policy in small and medium enterprises (SMEs): pecking order theory and trade-off theory. Panel data methodology is used to test the empirical hypotheses over a sample of 6482 Spanish SMEs during the five-year period 1994?1998. The results suggest that both theoretical approaches contribute to explain capital structure in SMEs. However, while we find evidence that SMEs attempt to achieve a target or optimum leverage (trade-off model), there is less support for the view that SMEs adjust their leverage level to their financing requirements (pecking order model). En este trabajo, exploramos dos de las teorías má…

Financial and fiscal shocks in the great recession and recovery of the Spanish economy

2020

In this paper we develop and estimate a new Bayesian DSGE model for the Spanish economy that has been designed to evaluate different structural reforms. The small open economy model incorporates a banking sector, consumers and entrepreneurs who accumulate debt, and a rich fiscal structure and monopolistic competition in products and labor markets, for a country in a currency union, with no independent monetary policy. The model can be used to evaluate ex-ante and ex-post policies and structural reforms and to decompose the evolution of macroeconomic aggregates according to different shocks. In particular, we estimate the contribution of financial and fiscal shocks to both the crisis of the …

A Novel Multi-step Finite-State Automaton for Arbitrarily Deterministic Tsetlin Machine Learning

2020

Due to the high energy consumption and scalability challenges of deep learning, there is a critical need to shift research focus towards dealing with energy consumption constraints. Tsetlin Machines (TMs) are a recent approach to machine learning that has demonstrated significantly reduced energy usage compared to neural networks alike, while performing competitively accuracy-wise on several benchmarks. However, TMs rely heavily on energy-costly random number generation to stochastically guide a team of Tsetlin Automata (TA) to a Nash Equilibrium of the TM game. In this paper, we propose a novel finite-state learning automaton that can replace the TA in TM learning, for increased determinis…

Floquet analysis of excitations in materials

2019

Abstract Controlled excitation of materials can transiently induce changed or novel properties with many fundamental and technological implications. Especially, the concept of Floquet engineering and the manipulation of the electronic structure via dressing with external lasers have attracted some recent interest. Here we review the progress made in defining Floquet material properties and give a special focus on their signatures in experimental observables as well as considering recent experiments realizing Floquet phases in solid state materials. We discuss how a wide range of experiments with non-equilibrium electronic structure can be viewed by employing Floquet theory as an analysis to…