Labor Market Regimes and Mobility through a Markov Chain in Chile

In this paper we analyze the dynamics of labor markets in Chile. Our goal is to understand how flexibility in the labor market has changed over time, and in particular, to relate this change with the legislation framework. We analyze mobility in four different periods, each of them associated with different labor regimes. Based on flows, we estimate transition probabilities across three relevant possible states: unemployment, employment, and out of the labor force. Our finding shows that since 1974 employment became less secure. The probability for an employed person of becoming unemployed almost doubled since 1974 and remained thereafter. Also, the probability of remaining unemployed increased from 26,1% in the period 1962-73, to over 40% in the periods 1974-79 and 1980-89, but felt to 25,6% after 1990. This in spite the average unemployment rate doubled between these two periods. The probabilities related with discourage and added worker effects were stable in the different periods considered, except since 1990, where the hypothesis of discouraged workers is challenged. Finally, whilst the natural rate of unemployment doubled after the reforms in 1974, it remained high until the last period, starting in 1990. Changes in participation compensated such changes, and hence, the expected length of unemployment did not increase dramatically in the period, remaining stable around two quarterslabor markets, transition probabilities, unemployment.

Isolated photon production and pion-photon correlations in high-energy pppp and pApA collisions

A phenomenological study of the isolated photon production in high energy $pp$ and $pA$ collisions at RHIC and LHC energies is performed. Using the color dipole approach we investigate the production cross section differential in the transverse momentum of the photon considering three different phenomenological models for the universal dipole cross section. We also present the predictions for the rapidity dependence of the ratio of $pA$ to $pp$ cross sections. As a further test of the formalism, for different energies and photon rapidites we analyse the correlation function in azimuthal angle $\Delta\phi$ between the photon and a forward pion. The characteristic double-peak structure of the correlation function around $\Delta \phi\simeq \pi$ observed previously for Drell-Yan pair production is found for isolated photon emitted into the forward rapidity region which can be tested by future experiments.Comment: 11 pages, 9 figures. Improved version to be published in Physical Review

Novel method for photovoltaic energy conversion using surface acoustic waves in piezoelectric semiconductors

This paper presents a novel principle for photovoltaic (PV) energy conversion using surface acoustic waves (SAWs) in piezoelectric semiconductors. A SAW produces a periodically modulated electric potential, which spatially segregates photoexcited electrons and holes to the maxima and minima of the SAW potential. The moving SAW collectively transports the carriers with the speed of sound to the electrodes made of different materials, which extract electrons and holes separately and generate dc output. The proposed active design is expected to have higher efficiency than passive designs of the existing PV devices and to produce enough energy to sustain the SAW.Comment: v.3 4 pages, 3 figures, submitted to proceedings of ECRYS-2011 to be published in Physica

Flow and hemocompatibility study of straight-bladed impeller VADs

Ventricular Assist Devices are continuous flow pumps that act as cardiac orthoses. The evaluation of the compatibility of such devices with blood involves, among other aspects, the study of thrombogenicity, hemolysis, and platelet activation. Computational Fluid Dynamics simulation is one of the tools used in this kind of evaluation. Thus, this work used Computational Fluid Dynamics simulations in the analysis of three Ventricular Assist Devices models under development, generating their velocity and pressure contours, their characteristic curves, and the distribution of shear stresses in their walls. A blood model has also been developed in order to estimate the damage inflicted on the blood by the devices. Steady-state simulations were performed, applying the Multiple Reference Frame method. The numerical blood modeling used the Lagrangean approach, with a discrete phase. The estimation of the damage on the blood was based on the relationship between the residence time of the discrete phase and the scalar shear stress. The prototype of one of the models was bench tested to validate the simulations. The simulation results relate the geometry of the models to the characteristics and magnitudes of the recirculation and stagnation regions and to the distribution of shear stresses. The energy performance of each pump and the blood damage index were used as comparison metrics between the devices

SINAES: UM ALERTA SOBRE A AUTOAVALIAÇÃO EM INSTITUIÇÕES DE ENSINO SUPERIOR - IES

Entendendo o processo de autoavaliação como um dos componentes chave do Sistema Nacional de Avaliação da Educação Superior – SINAES, objetiva-se com este artigo identificar e discutir os entraves que dificultam a sua execução no contexto IES. O suporte teórico adotado neste trabalho refere-se ao conceito de gestão em IES, na teoria estratégica em organizações e sistemas complexos. A revisão da literatura apresenta as tendências emergentes em estudos empíricos de avaliação de IES no contexto nacional, na legislação concernente ao SINAES, aos documentos produzidos pelo INEP e CONAES, assim como a estudos voltados a execução da estratégia. Utiliza-se para a abordagem do problema a técnica qualitativa, sendo que os objetivos de estudo são desenvolvidos por meio de uma pesquisa explicativa e a estratégia da pesquisa é de caráter bibliográfico. Há indicativos de que, de forma equivalente a outras organizações, as barreiras para execução da autoavaliação de forma efetiva em IES, estão vinculados a falta de elementos como: uma liderança atuante, persistente com atitudes para as mudanças essenciais na cultura destas organizações; capacitação que crie um ambiente mais receptivo às novas mudanças; programas que incentivem o envolvimento dos funcionários; sistemas e mecanismos de gestão estratégica e processos alinhados a estratégia institucional