Comparisons for Esta-Task3: Cles and Cesam

We present the results of comparing three different implementations of the microscopic diffusion process in the stellar evolution codes CESAM and CLES. For each of these implementations we computed models of 1.0, 1.2 and 1.3 M$_{\odot}$. We analyse the differences in their internal structure at three selected evolutionary stages, as well as the variations of helium abundance and depth of the stellar convective envelope. The origin of these differences and their effects on the seismic properties of the models are also considered.Comment: 10 pages, 8 figures, Joint HELAS and CoRoT/ESTA Workshop on Solar/Stellar Models and Seismic Analysis Tools, Novembre, Porto 2007 To be published in EAS Publications Serie

Comparison of experimental and numerical sloshing loads in partially filled tanks

Sloshing phenomenon consists in the movement of liquids inside partially filled tanks, whichgenerates dynamic loads on the tank structure. Resulting impact pressures are of great importance in assessingstructural strength, and their correct evaluation still represents a challenge for the designer due to the highnonlinearities involved, with complex free surface deformations, violent impact phenomena and influence of airtrapping. In the present paper a set of two-dimensional cases for which experimental results are available areconsidered to assess merits and shortcomings of different numerical methods for sloshing evaluation, namely twocommercial RANS solvers (FLOW-3D and LS-DYNA), and two own developed methods (Smoothed ParticleHydrodynamics and RANS). Impact pressures at different critical locations and global moment induced by watermotion for a partially filled tank with rectangular section having a rolling motion have been evaluated and resultsare compared with experiments

Why, when, and how fast innovations are adopted

When the full stock of a new product is quickly sold in a few days or weeks, one has the impression that new technologies develop and conquer the market in a very easy way. This may be true for some new technologies, for example the cell phone, but not for others, like the blue-ray. Novelty, usefulness, advertising, price, and fashion are the driving forces behind the adoption of a new product. But, what are the key factors that lead to adopt a new technology? In this paper we propose and investigate a simple model for the adoption of an innovation which depends mainly on three elements: the appeal of the novelty, the inertia or resistance to adopt it, and the interaction with other agents. Social interactions are taken into account in two ways: by imitation and by differentiation, i.e., some agents will be inclined to adopt an innovation if many people do the same, but other will act in the opposite direction, trying to differentiate from the "herd". We determine the conditions for a successful implantation of the new technology, by considering the strength of advertising and the effect of social interactions. We find a balance between the advertising and the number of anti-herding agents that may block the adoption of a new product. We also compare the effect of social interactions, when agents take into account the behavior of the whole society or just a part of it. In a nutshell, the present model reproduces qualitatively the available data on adoption of innovation.Comment: 11 pages, 13 figures (with subfigures), full paper (EPJB 2012) on innovation adoption mode

Emergence of communities on a coevolutive model of wealth interchange

We present a model in which we investigate the structure and evolution of a random network that connects agents capable of exchanging wealth. Economic interactions between neighbors can occur only if the difference between their wealth is less than a threshold value that defines the width of the economic classes. If the interchange of wealth cannot be done, agents are reconnected with another randomly selected agent, allowing the network to evolve in time. On each interaction there is a probability of favoring the poorer agent, simulating the action of the government. We measure the Gini index, having real world values attached to reality. Besides the network structure showed a very close connection with the economic dynamic of the system.Comment: 5 pages, 7 figure

Entropy and equilibrium state of free market models

Many recent models of trade dynamics use the simple idea of wealth exchanges among economic agents in order to obtain a stable or equilibrium distribution of wealth among the agents. In particular, a plain analogy compares the wealth in a society with the energy in a physical system, and the trade between agents to the energy exchange between molecules during collisions. In physical systems, the energy exchange among molecules leads to a state of equipartition of the energy and to an equilibrium situation where the entropy is a maximum. On the other hand, in the majority of exchange models, the system converges to a very unequal condensed state, where one or a few agents concentrate all the wealth of the society while the wide majority of agents shares zero or almost zero fraction of the wealth. So, in those economic systems a minimum entropy state is attained. We propose here an analytical model where we investigate the effects of a particular class of economic exchanges that minimize the entropy. By solving the model we discuss the conditions that can drive the system to a state of minimum entropy, as well as the mechanisms to recover a kind of equipartition of wealth

Kondo lattice model with a direct exchange interaction between localized moments

We study the Kondo lattice model with a direct antiferromagnetic exchange interaction between localized moments. Ferromagnetically long-range ordered state coexisting with the Kondo screening shows a continuous quantum phase transition to the Kondo singlet state. We obtain the value of the critical point where the magnetizations of the localized moments and the conduction electrons vanish. The magnetization curves yield a universal critical exponent independent of the filling factors and the strength of the interaction between localized moments. It is shown that the direct exchange interaction between localized moments introduces another phase transition from an antiferromagnetic ordering to a ferromagnetic ordering for small Kondo exchange interaction. We also explain the local minimum of the Kondo temperature in recent experiments.Comment: 6 pages, 5 figures, final versio

Evidence for magnetic clusters in BaCoO3_3

Magnetic properties of the transition metal oxide BaCoO$_3$ are analyzed on the basis of the experimental and theoretical literature available via ab inito calculations. These can be explained by assuming the material to be formed by noninteracting ferromagnetic clusters of about 1.2 nm in diameter separated by about 3 diameters. Above about 50 K, the so-called blocking temperature, superparamagnetic behavior of the magnetic clusters occurs and, above 250 K, paramagnetism sets in.Comment: 4 pages, 1 figur

Avoiding communication barriers in the classroom: the APEINTA project

Education is a fundamental human right, however unfortunately not everybody has the same learning opportunities. For instance, if a student has hearing impairments, s/he could face communications barriers in the classroom, which could affect his/her learning process. APEINTA is a Spanish educational project that aims for inclusive education for all. This project proposes two main accessible initiatives: (1) real-time captioning and text-to-speech (TTS) services in the classroom and (2) accessible Web-learning platform out of the classroom with accessible digital resources. This paper presents the inclusive initiatives of APEINTA. Also an evaluation of the into-the-classroom initiative (real-time captioning and TTS services) is presented. This evaluation has been conducted during a regular undergraduate course at a university and during a seminar at an integration school for deaf children. Forty-five hearing students, 1 foreign student, 3 experts in captioning, usability and accessibility, and 20 students with hearing impairments evaluated these services in the classroom. Evaluation results show that these initiatives are adequate to be used in the classroom and that students are satisfied with them.Publicad