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

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

Physics Beyond the Standard Model: Focusing on the Muon Anomaly

We present a model based on the implication of an exceptional E_{6}-GUT symmetry for the anomalous magnetic moment of the muon. We follow a particular chain of breakings with Higgses in the 78 and 351 representations. We analyse the radiative correction contributions to the muon mass and the effects of the breaking of the so-called Weinberg symmetry. We also estimate the range of values of the parameters of our model.Comment: 14 RevTeX pages, 5 figure

Synthesis of 2,6-bis-(oxazolyl)pyridine ligands for luminescent Ln(III) complexes

Submitted to the European Journal of Organic ChemistryNew bis-(oxazolyl)pyridine ligands for Ln(III) ions were prepared using a expeditious methodology from threonine and dipicolinic acid chloride. The synthetic strategy includes a dehydration step to give a bis-dehydroaminobutyric acid derivative followed by bromination and cyclization with DBU. Photophysical studies of Eu(III) and Tb(III) complexes of these ligands showed that the 2,6-bis-(oxazolyl)pyridine moiety acts as an effective sensitizer for lanthanide luminescence and indicate the formation of 3:1 complexes [Ln-(bis-(oxazole)pyridine)3]3+.Fundação para a Ciência e Tecnologia (FCT), QREN, FEDER/E

Effectiveness factor for immobilized biocatalysts: two substratestwo products reactions

Immobilized enzymes are being increasingly used as biocatalysts in numerous processes to obtain high-value products for the pharmaceutical, flavour and fragrance industries (Gandhi et al., 2000). The major advantages of immobilization include the increase in enzyme stability, the possibility of enzyme reutilization and the easy separation of the biocatalysts from the reaction mixture. However, it is necessary to account for mass transfer limitations that, under some conditions, may arise in these systems (Gómez et al., 2003; Jeison et al., 2003). These resistances comprise the effects of intraparticle diffusion and external mass-transfer. Given the complexity of the kinetics of multisubstrate enzyme reactions, reactor modelling studies that account for mass-transfer phenomena are so far limited to single-substrate ones (Gómez et al., 2003). To compare the observed reaction rate with the reaction rate in the absence of mass-transfer limitations, an overall effectiveness factor is usually calculated (Gómez et al., 2003; Jeison et al., 2003). In this work, a model is developed to calculate the overall effectiveness factor for immobilized enzymes that carry out irreversible two substrates-two products reactions following kinetic mechanisms such as the Ternary Complex or the Ping-Pong Bi-Bi with inhibition by the second substrate. The model has two dimensionless parameters for each substrate – Thiele modulus (reaction/intraparticle diffusion), Biot number (film diffusion/intraparticle diffusion) – and one related to the reaction kinetics. Their influence on the effectiveness factor is analysed. The results obtained can be applied in the design and simulation of enzymatic reactors

Direct current control of an active power filter for harmonic elimination, power factor correction and load unbalancing compensation

An active power filter is designed, simulated, implemented, and tested. It can work in different modes: active power filtering, power factor correction, and load unbalance compensation. It is based on a current controlled voltage-source inverter with fixed carrier PWM. The control algorithm generates the source reference currents based on the controlled DC link voltage. The dimensioning criteria of the inductive and capacitive power components is discussed. The implementation is validated with simulated and experimental results obtained in a 5 kVA prototype

A modernização agropecuária nas microrregiões do estado de Minas Gerais

Este estudo objetivou identificar e caracterizar grupos distintos de microrregiões homogêneas quanto ao grau de modernização agropecuária no Estado de Minas Gerais. Para tanto foram empregadas as técnicas de análise fatorial e de análise de agrupamento, a fim de obter os fatores que refletem o padrão tecnológico e cujas relações permitam formar grupos de microrregiões semelhantes. Foram identificados 10 grupos distintos de microrregiões homogêneas, cada um possuindo combinação distinta dos fatores encontrados e que reflete o seu nível tecnológico. Os grupos encontrados constituem informação preliminar para aplicação localizada de políticas de apoio ao setor, bem como para a tomada de decisão por parte dos agentes da iniciativa privada

Time-to-Arrival and Useful Field of View: Associations with Reported Driving Difficulties Among Older Adults

The purpose of this study was to determine self-reported driving difficulties related to time-to-arrival (TTA) and/or useful field of view (UFOV), to identify associations between TTA and UFOV, and to compare the TTA estimated accuracy between different vehicle speed approaches. Thirty-eight male and female active drivers ages 61 to 81 years (70,2 ± 5,0 years) participated in this study. The UFOV® test was applied. TTA was studied with a removal paradigm, using two vehicle speeds (50 and 70km/h) for data collection. A driving habits questionnaire was administered, including items concerning driving difficulties. Results showed that lower performances in divided attention (subtest 2 of UFOV®) were significantly associated with reported difficulties in hightraffic intersections, trouble seeing the signs in time to respond to them, and problems judging the speed or distance of an approaching vehicle. Concerning TTA, greater response bias and/or greater response inconsistency were significantly associated with difficulties in overtaking other cars, difficulties seeing the signs in time to react to them, difficulties in the speed or distance perception of an oncoming vehicle. Low associations were found between UFOV and TTA measures. TTA estimated accuracy increased when the vehicle traveled at higher speeds. We concluded that both TTA and UFOV seem to be important measures to identify driving difficulties in older adults. The TTA could be relevant in measuring specific aspects of visual information processing in addition to other instruments like UFOV®

Determination of iron in soils by flow injection atomic absorption spectrometry

A single-channel flow injection system was optimized for the determination of available iron (Fe) in soil extracts by atomic absorption spectrophotometry. This method of introducing the samples in the spectrophotometer worked particularly well in preventing blockage of the burner head which was observed in the conventional introduction of Fe for its determination by atomic absorption spectrophotometry. The appropriate selection of the manifold parameters, such as injection volume, tube length and flow rate, allowed introduction of any soil extract without requiring any pre-treatment. This system allowed determinations at a detection limit of 0.36 mg L-1 to 5 mg L-1, with an output of 300 determinations per hour. The results obtained for analysis of 15 soil extracts were in good agreement with those provided by the colorimetric method, with average relative deviations of 1.6%. Relative standard deviations of 4.8, 2.5, and 2.3% were obtained for contents of 1.03, 1.85, and 3.99 mg Fe L-1, respectively

Flow injection systems for elemental soil analysis determinations

Flow injection analysis (FIA) is becoming an important automated procedure for the elemental analysis of agricultural and environmental samples. This paper reviews the application of the FIA technique for soil elemental analysis determinations, giving short descriptions of the required flow manifolds by highlighting some of their most important features