Diferença e desigualdade: dilemas docentes no ensino fundamental

Embora a incorporação das questões da diferença nas pesquisas e práticas educacionais tenha visivelmente se acentuado nos últimos anos, sua abordagem ainda traz mais inquietações do que respostas. Neste texto, pretendemos contribuir para tais discussões, focalizando a tensão desigualdade-diferença identificada em representações de professores e professoras expressas no grupo focal realizado no contexto da pesquisa Multiculturalismo, direitos humanos e educação: a tensão entre igualdade e diferença. Entre as diversas abordagens que vem se afirmando no continente latino-americano, operamos com a perspectiva intercultural. Desse modo, problematizamos as significações atribuídas à palavra "diferença" pelos participantes do grupo focal em tela, para, em conclusão, discutir a associação da expressão "diferença" a "preconceito" e "discriminação", assim como sua significação como "desigualdade". Destacamos a produtividade do grupo focal como alternativa de entrevista coletiva, na medida em que se mostrou espaço privilegiado para a interação dos participantes, oportunizando construções discursivas menos direcionadas pela pesquisa e mais próximas das suas práticas cotidianas.

Trabalho docente na escola fundamental: questões candentes

Derivado de investigação mais ampla sobre a estrutura da escola fundamental, este trabalho apresenta e discute resultados de pesquisa de cunho qualitativo, realizada em escola pública de ensino fundamental, analisando questões relacionadas ao trabalho docente, com destaque para a assistência pedagógica, para as condições objetivas de trabalho na escola e para a gestão do tempo na prática docente cotidiana. O artigo se ampara num conceito de educação como prática democrática, construtora de personalidades humano-históricas, para sugerir a necessidade de transformação na estrutura da escola atual, e traz conclusões a respeito da necessidade de se considerar o caráter peculiar e único do trabalho docente, no encaminhamento de soluções e iniciativas visando à efetiva realização de um ensino de qualidade.

Efeitos de escolas e municípios na qualidade do ensino fundamental

Este estudo, em linha com a literatura sobre os efeitos das escolas, tem como principal objetivo identificar escolas públicas e municípios que contribuem para elevar significativamente os resultados de seus alunos. Para isso, comparamos os efeitos das escolas e dos municípios avaliados com outros indicadores de qualidade educacional, como o Índice de Desenvolvimento da Educação Básica - Ideb - e os gastos municipais por aluno, e também a eficiência das redes de ensino públicas dentro dos municípios. Utilizamos as bases de dados da Prova Brasil de 2005, 2007, 2009 e 2011, e estimamos modelos de regressão hierárquicos, que possibilitam um melhor controle sobre os fatores contextuais que influenciam os resultados dos alunos. A conclusão é que os efeitos das escolas e dos municípios são melhores indicadores da qualidade educacional do que o Ideb. Identificamos inúmeras escolas e municípios que, consideradas as características sociodemográficas dos alunos e do contexto escolar, têm efeitos muito acima do esperado e com eficiência de gastos.

Efetividade da política para o Ensino Fundamental em municípios brasileiros

Este artigo discute resultados de pesquisa sobre condições de qualidade educacional a partir da análise da aplicação do Índice de Condições de Qualidade dos anos iniciais do ensino fundamental das redes municipais, nos anos de 2007 e 2011. Tomando componentes da política educacional, especificamente as condições de trabalho docente, as condições materiais e estruturais das escolas e as condições de gestão escolar, esse índice dimensiona o possível esforço da política em responder às demandas educacionais postas na realidade brasileira. O estudo conclui mostrando que aparentemente as condições gerais de qualidade educacional no país têm sido incrementadas e os municípios que apresentam melhores resultados são aqueles que atendem até 1000 estudantes ou mais de 10 mil estudantes nas redes municipais.

Recursos informacionais para o ensino fundamental

Caracteriza os produtores de recursos informacionais para o ensino fundamental no Brasil. Identifica, mediante o estudo dos catálogos por eles distribuídos, o modo como são divulgados seus produtos. Conclui que a indústria editorial brasileira voltada para o ensino fundamental apresenta uma produção diversificada, oferecendo uma variedade de materiais, típica do ambiente informacional da sociedade contemporânea. A análise dos catálogos aponta algumas deficiências nas informações necessárias à seleção dos materiais.

Predicting soil erosion using Rusle and NDVI time series from TM Landsat 5

The objective of this work was to evaluate the seasonal variation of soil cover and rainfall erosivity, and their influences on the revised universal soil loss equation (Rusle), in order to estimate watershed soil losses in a temporal scale. Twenty-two TM Landsat 5 images from 1986 to 2009 were used to estimate soil use and management factor (C factor). A corresponding rainfall erosivity factor (R factor) was considered for each image, and the other factors were obtained using the standard Rusle method. Estimated soil losses were grouped into classes and ranged from 0.13 Mg ha-1 on May 24, 2009 (dry season) to 62.0 Mg ha-1 on March 11, 2007 (rainy season). In these dates, maximum losses in the watershed were 2.2 and 781.5 Mg ha-1 , respectively. Mean annual soil loss in the watershed was 109.5 Mg ha-1 , but the central area, with a loss of nearly 300.0 Mg ha-1 , was characterized as a site of high water-erosion risk. The use of C factor obtained from remote sensing data, associated to corresponding R factor, was fundamental to evaluate the soil erosion estimated by the Rusle in different seasons, unlike of other studies which keep these factors constant throughout time.

Estudo do estado fundamental de aglomerados de silício via redes neurais

We introduce a global optimization method based on the cooperation between an Artificial Neural Net (ANN) and Genetic Algorithm (GA). We have used ANN to select the initial population for the GA. We have tested the new method to predict the ground-state geometry of silicon clusters. We have described the clusters as a piling of plane structures. We have trained three ANN architectures and compared their results with those of pure GA. ANN strongly reduces the total computational time. For Si10, it gained a factor of 5 in search speed. This method can be easily extended to other optimization problems.

Uma introdução à espectroscopia atômica: II - o espectro do sódio

The present article is devoted to Chemistry or Physics undergraduate students, given their difficulty to understand fundamental concepts and technical language used in atomic spectroscopy and quantum mechanics. An easy approach is shown in the treatment of the emission spectrum of the sodium atom without any involved calculations. In a previous article, the hydrogen spectrum was considered and the energy degeneracy of the angular momentum quantum number was observed. For the sodium spectrum, due to the valence electron penetration into internal shells, a breakdown of this degeneracy occurs and a dependence of this penetration on the angular momentum quantum number is observed. The eigenvalues are determined introducing the quantum defect correction (Rydberg correction) in the denominator of the Balmer equation, and the energy diagram is obtained. The intensity ratio for the observed doublets is explained by introducing new wave functions, containing the magnetic quantum number of the total angular momentum.

Foam-forming properties of Ilex paraguariensis (mate) saponin: foamability and foam lifetime analysis by Weibull equation

Saponins are natural soaplike foam-forming compounds widely used in foods, cosmetic and pharmaceutical preparations. In this work foamability and foam lifetime of foams obtained from Ilex paraguariensis unripe fruits were analyzed. Polysorbate 80 and sodium dodecyl sulfate were used as reference surfactants. Aiming a better data understanding a linearized 4-parameters Weibull function was proposed. The mate hydroethanolic extract (ME) and a mate saponin enriched fraction (MSF) afforded foamability and foam lifetime comparable to the synthetic surfactants. The linearization of the Weibull equation allowed the statistical comparison of foam decay curves, improving former mathematical approaches.

Resolvendo a equação de Schrödinger utilizando procedimentos numéricos fundamentais

A combination of the variational principle, expectation value and Quantum Monte Carlo method is used to solve the Schrödinger equation for some simple systems. The results are accurate and the simplicity of this version of the Variational Quantum Monte Carlo method provides a powerful tool to teach alternative procedures and fundamental concepts in quantum chemistry courses. Some numerical procedures are described in order to control accuracy and computational efficiency. The method was applied to the ground state energies and a first attempt to obtain excited states is described.

Solving Schrödinger equation for two dimensional potentials using supersymmetry

The formalism of supersymmetric Quantum Mechanics can be extended to arbitrary dimensions. We introduce this formalism and explore its utility to solve the Schrödinger equation for a bidimensinal potential. This potential can be applied in several systems in physical and chemistry context , for instance, it can be used to study benzene molecule.

Mathematical equation correction to spectral and transport interferences in high-resolution continuum source flame atomic absorption spectrometry: determination of lead in phosphoric acid

In this work, a new mathematical equation correction approach for overcoming spectral and transport interferences was proposed. The proposal was applied to eliminate spectral interference caused by PO molecules at the 217.0005 nm Pb line, and the transport interference caused by variations in phosphoric acid concentrations. Correction may be necessary at 217.0005 nm to account for the contribution of PO, since Atotal217.0005 nm = A Pb217.0005 nm + A PO217.0005 nm. This may be easily done by measuring other PO wavelengths (e.g. 217.0458 nm) and calculating the relative contribution of PO absorbance (A PO) to the total absorbance (Atotal) at 217.0005 nm: A Pb217.0005 nm = Atotal217.0005 nm - A PO217.0005 nm = Atotal217.0005 nm - k (A PO217.0458 nm). The correction factor k is calculated from slopes of calibration curves built up for phosphorous (P) standard solutions measured at 217.0005 and 217.0458 nm, i.e. k = (slope217.0005 nm/slope217.0458 nm). For wavelength integrated absorbance of 3 pixels, sample aspiration rate of 5.0 ml min-1, analytical curves in the 0.1 - 1.0 mg L-1 Pb range with linearity better than 0.9990 were consistently obtained. Calibration curves for P at 217.0005 and 217.0458 nm with linearity better than 0.998 were obtained. Relative standard deviations (RSD) of measurements (n = 12) in the range of 1.4 - 4.3% and 2.0 - 6.0% without and with mathematical equation correction approach were obtained respectively. The limit of detection calculated to analytical line at 217.0005 nm was 10 µg L-1 Pb. Recoveries for Pb spikes were in the 97.5 - 100% and 105 - 230% intervals with and without mathematical equation correction approach, respectively.

Bound state solutions of schrödinger equation for a more general exponential screened coulomb potential via Nikiforov-Uvarov method

The arbitrary angular momentum solutions of the Schrödinger equation for a diatomic molecule with the general exponential screened coulomb potential of the form V(r) = (- a / r){1+ (1+ b )e-2b } has been presented. The energy eigenvalues and the corresponding eigenfunctions are calculated analytically by the use of Nikiforov-Uvarov (NU) method which is related to the solutions in terms of Jacobi polynomials. The bounded state eigenvalues are calculated numerically for the 1s state of N2 CO and NO

Evapotranspiration and crop coefficient of drip irrigated watermelon in Piaui coastline, Brazil

The knowledge of the evapotranspiration (ETc) and crop coefficient (Kc) is fundamental to plan and to manage the irrigation of any crop. The aim of this study was to determine the daily and hourly evapotranspiration of drip irrigated watermelon (Citrullus Lanatus, var. Crimson Sweet) and crop coefficient (Kc) in each crop development phase. The experiment was carried out in an experimental area of 1.27 ha of Embrapa Mid-North, localized in Parnaíba (02°54'S, 41°47'W and 46 m above of sea), State of Piauí, Brazil, from September to November, 2006. Electronic weighing lysimeters of 1.5 m x 1.5 m wide and long and 1.0 m deep were used to obtain the evapotranspiration. The plants were drip irrigated with a lateral row per plant row and drippers spaced 0.5 m from each other. The reference evapotranspiration (ETo) was estimated using the Penman-Monteith equation from the climatic data obtained by electronic sensors. The total evapotranspiration during the watermelon crop cycle cultivated in the state of Piauí was 233.87 mm, with mean values of 3.7 mm day-1, minimum of 1.18 and maximum of 8.14 mm day-1. The Kc of the drip irrigated watermelon was 0.18 in the initial stage of crop growth; 0.18 to 1.3, in crop development stage; 1.3 in the intermediate stage and 0.43 in the final stage.

Estimation of evaporation in the Banabuiú dam, in the state of Ceará, Brazil, by different combined methods, derived from the Penman equation

The state of Ceará, Brazil, has 75% of its area covered by Brazilian semiarid, with its peculiar features. In this state, the dams are constituted in water structure of strategic importance, ensuring, both in time and space, the development and supply of water to population. However, construction of reservoirs results in various impacts that should be carefully observed when deciding on their implementation. One of the impacts identified as negative is the increased evaporation, which constitutes a major component of water balance in reservoirs, especially in arid regions. Several methods for estimating evaporation have been proposed over time, many of them deriving from the Penman equation. This study evaluated six different methods for estimating evaporation in order to determine the most suitable for use in hydrological models for water balance in reservoirs in the state of Ceará. The tested methods were proposed by Penman, Kohler-Nordenson-Fox, Priestley-Taylor, deBruim-Keijman, Brutsaert-Stricker and deBruim. The methods presented good performance when tested for water balance during the dry season, and the Priestley-Taylor was the most appropriate, since the data from de simulated water balance with evaporation estimated by this method were the closest of the water balance data observed from measures of reservoir level and the elevation-volume curve provided by the Company of Management of Water Resources of the state of Ceará - COGERH.