O efeito de factores climáticos no consumo de energia eléctrica

Neste trabalho identificam-se as causas responsáveis por variações no consumo horário de energia com base na identificação de padrões e relações entre os dados de consumo e várias variáveis climatéricas. Para tal utilizam-se técnicas de data mining, nomeadamente a metodologia CRISP-DM e software de data warehouse MS SQL Server. Assim, foi possível verificar que as variáveis climatéricas têm influência muito significativa na produção de energia eléctrica, tendo sido possível prever os consumos de 2007 com um erro absoluto médio de 1,4 MW. Identificam-se ainda vários padrões no comportamento do consumo ou produção de energia eléctrica, nem todos espectáveis face ao conhecimento actual de domínio.info:eu-repo/semantics/publishedVersio

Factores climáticos no consumo de energia eléctrica: um caso com utilização de data mining.

4ª Conferência Ibérica de Sistemas e Tecnologias de Informação, 17 a 20 de Junho de 2009, Póvoa de Varzim.Este trabalho tem por objectivo identificar causas responsáveis por variações no consumo horário de energia com base na identificação de padrões e relações entre os dados de consumo e várias variáveis climatéricas. Para tal utilizam-se técnicas de data mining, nomeadamente a metodologia CRISP-DM e software de data warehouse MS SQL Server. Assim, foi possível verificar que as variáveis climatológicas têm influência muito significativa na produção de energia eléctrica, tendo sido possível prever os consumos de 2007 com um erro absoluto médio de 1,4 MW. Identificam-se ainda vários padrões no comportamento do consumo ou produção de energia eléctrica, nem todos espectáveis face ao conhecimento actual de domínio

Stress induced magnetic anisotropy on BaTiO3-CoFe2O4 nanogranular composite thin films

The influence of stress on the magnetic properties of BaTiO3-CoFe2O4 nanocomposites deposited by laser ablation on platinum covered Si(001) substrates, was characterized. The cobalt ferrite phase was under compressive strain in the growth direction that progressively relaxed as its concentration increased. A stress induced perpendicular magnetic anisotropy was observed, that decreased with increasing CoFe2O4 content, due to the relaxation of stress in the films.This work has been financially supported by the Portuguese Foundation for Science and Technology (FCT) and FEDER, through the projects POCI/CTM/60181/2004, FEDER/POCTI/0155/94, and through the Associated Laboratory-IN

Epitope mapping of a single repetitive unit of the B13 Trypanosoma cruzi antigen as fusions to Escherichia coli LamB protein

B13, one of the immunodominant antigens of Trypanosoma cruzi, is composed of repeats of a 12-amino-acid motif. Using synthetic peptides, the sequence FGQAAAGDK was previously shown to contain the B13 immunodominant epitope recognized by chagasic patients sera. To investigate the effects of neighboring sequences in the immunodominance, we tested serum recognition of two B13 sequences fused to LamB. GDKPSPFGQAAA-LamB and FGQAAAGDKPSP-LamB were recognized, respectively, by 15% and 80% of 80 sera reactive to B13 antigen. Recognition of FGQAAAGDKPSP-LamB was inhibited by AAAGDK-containing synthetic peptides. FGQAAAGDKPSP-LamB competed with a B13 recombinant protein containing 16.6 repeats for binding to chagasic antibodies. These results strengthen previous conclusions on the immunodominant epitope of B13 and provide a comparison of two methods for epitope mapping. (C) 2004 Published by Elsevier B.V. on behalf of the Federation of European Microbiological Societies.UNIFESP, Escola Paulista Med, Dept Microbiol Immunol & Parasitol, BR-01023062 São Paulo, BrazilUniv São Paulo, Inst Quim, Dept Bioquim, BR-01498 São Paulo, BrazilUniv São Paulo, Fac Med, Inst Coracao, Lab Immunol Transplantes, BR-01498 São Paulo, BrazilUNIFESP, Escola Paulista Med, Dept Microbiol Immunol & Parasitol, BR-01023062 São Paulo, BrazilWeb of Scienc

Cobalt ferrite thin films deposited by electrophoresis on p-doped Si substrates

The structural and magnetic properties of cobalt ferrite (CoFe2O4) thin films deposited by electrophoresis on p-doped Si(001) substrates have been characterized. The films were polycrystalline and composed by cobalt ferrite with the cubic spinnel structure. The observed decrease of the coercive field with the sixth power of the grain size was indicative of a competition between the magnetocrystalline anisotropy and the exchange coupling energy, on these randomly oriented nanosized grained films.J. Barbosa and M.P. Proenca gratefully acknowledge a PhD grant from Fundacao para a Ciencia e Tecnologia (SFRH/BD/41913/2007 and SFRH/BD/43440/2008, respectively)

Structural and magnetic characterization of LaSrMnO3 thin films deposited by laser ablation on MgO substrates

La2/3Sr1/3MnO3-delta thin films were deposited by laser ablation on MgO substrates under low oxygen pressure cool down. Their structural and magnetic properties are presented. The magnetic and electrical resistivity measurements indicate a reduction of the Curie and the metal-insulator transition temperatures due to the formation of magnetic inhomogeneneous films, where clusters of a metallic phase are mixed in a magnetically disordered insulating matrix. By a low-angle X-ray reflectivity study we show that the thin films are chemically inhomogeneous with an oxygen deficiency in bulk of the film when compared with the film/air interfacial region

Dossiê 'Controvérsias públicas em Portugal e no Brasil.

As narrativas públicas sobre a modernidade política têm estado assentes, desde a sua gênese, em princípios marcados por ambivalências e por ambiguidades com expressões públicas diversas. Na verdade, os acontecimentos políticos na origem da reconfiguração dos Estados modernos na segunda metade do século XVIII expressam dilemas associados, por um lado, à extensão das liberdades políticas e econômicas e, por outro, à extensão da intervenção de serviços públicos visando ordenar seus territórios, quer do ponto de vista administrativo pela definição das suas fronteiras, quer do ponto de vista econômico com a institucionalização de serviços tributários e aduaneiros, quer ainda com a organização de dispositivos de vigilância e de uso legítimo da violência interna e externa. À medida que, na história da modernidade, os bens classificados por convenções estatais como públicos vão se tornando objeto de um trabalho aturado de alargamento para responder quer a demandas socialmente vinculadas a movimentos sociais quer a exigências éticas e morais diversas visando ao reconhecimento de novos direitos, quer ainda para repostar situações tornadas socialmente insuportáveis, a definição das políticas e das ações públicas objetivando a aplicação de instrumentos que zelem por sua distribuição justa não deixam de gerar controvérsias diversas

Dynamic Simulations of the Kosterlitz-Thouless Phase Transition

Based on the short-time dynamic scaling form, a novel dynamic approach is proposed to tackle numerically the Kosterlitz-Thouless phase transition. Taking the two-dimensional XY model as an example, the exponential divergence of the spatial correlation length, the transition temperature $T_{KT}$ and all critical exponents are computed. Compared with Monte Carlo simulations in equilibrium, we obtain data at temperatures nearer to $T_{KT}$.Comment: to appear in Phys. Rev. E in Rapid Communicatio

Major electrocardiographic abnormalities according to the Minnesota coding system among Brazilian adults (from the ELSA-Brasil cohort study)

The electrocardiogram is a simple and useful clinical tool; nevertheless, few studies have evaluated the prevalence of electrocardiographic abnormalities in the Latin American population. This study aims to evaluate the major electrocardiographic abnormalities according to the Minnesota coding system in Brazilian adults, stratified by gender, age, race, and cardiovascular risk factors. Data from 14,424 adults (45.8% men, age 35 to 74 years) were obtained at baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), according to standardized protocol. The electrocardiogram were obtained with the Burdick Atria 6100 machine, stored on Pyramis System, automatically coded according to the Minnesota coding system by the Glasgow University software and then manually revised. Major abnormalities were more prevalent in men than women (11.3% and 7.9%, p <0.001). These differences were consistent through the different age groups, race, and number of cardiovascular risk factors. Electrocardiographic major abnormalities were more prevalent in black participants for both men (black: 15.1%, mixed: 10.4%, white: 11.1%, p = 0.001) and women (black: 10%, mixed: 7.6%, white: 7.2%, p = 0.004). In conclusion, in this large sample of Brazilian adults, the prevalence of major electrocardiographic abnormalities was higher among men, the elderly, black, and among people with more cardiovascular risk factors