The use of the two-body energy to study problems of escape/capture Ernesto Vieira Neto1

The problem of escape/capture is encountered in many problems of the celestial mechanics -the capture of the giants planets irregular satellites, comets capture by Jupiter, and also orbital transfer between two celestial bodies as Earth and Moon. To study these problems we introduce an approach which is based on the numerical integration of a grid of initial conditions. The two-body energy of the particle relative to a celestial body defines the escape/capture. The trajectories are integrated into the past from initial conditions with negative two-body energy. The energy change from negative to positive is considered as an escape. By reversing the time, this escape turns into a capture. Using this technique we can understand many characteristics of the problem, as the maximum capture time, stable regions where the particles cannot escape from, and others. The advantage of this kind of approach is that it can be used out of plane (that is, for any inclination), and with perturbations in the dynamics of the n-body problem. © 2005 International Astronomical Union.

Further investigation of the initial fission-track length and geometry factor in apatite fission-track thermochronology

The external detector method (EDM) is a widely used technique in fission track thermochronology (FTT) in which two different minerals are concomitantly employed: spontaneous tracks are observed in apatite and induced ones in the muscovite external detector. They show intrinsic differences in detection and etching properties that should be taken into account. In this work, new geometry factor values, g, in apatite, were obtained by directly measuring the ρed/ρis ratios and independently determined [GQR]ed/is values through the measurement of projected lengths. Five mounts, two of which were large area prismatic sections and three samples composed of random-orientation pieces have been used to determine the g-values. A side effect of applying EDM is that the value of the initial confined induced fission track, L0, is not measured in routine analyses. The L 0-value is an important parameter to quantify with good confidence the degree of annealing of the spontaneous fission tracks in unknown-age samples, and is essential for accurate thermal history modeling. The impact of using arbitrary L0-values on the inference of sample thermal history is investigated and discussed. The measurement of the L0-value for each sample to be dated using an extra irradiated apatite mount is proposed. This extra mount can be also used for determining the g value as an extension of the ρed/ρis ratio method. Eight apatite samples from crystalline basement, with grains at random orientation, were used to determine the g-values. The results found are statistically in agreement with the values found for apatite samples (from Durango, Mexico) measured in prismatic section and also measured at random orientation. There was no observable variation in efficiency regarding crystal orientation, showing that it is relatively safe using non-prismatic grains, especially in samples with paucity of grains, as it is the case of most basin samples. Implications for the ζ-calibration and for the calibration of the direct (spectrometer-based) fission-track dating are also discussed.

Estudo da bioconversão da lactose do soro de leite em bioetanol pela evedura Kluyveromyces marxianus 229

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Criando novos tabuleiros para o jogo Tri-Hex e sua validação didático-pedagógica na formação continuada de professores de matemática: uma contribuição para a geometria das séries finais do ensino fundamental

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Apropriação/vivência de valores em questão: repercussões na prática pedagógica

Pós-graduação em Educação - FFC

Programa de Educação de Jovens e Adultos como Processo Formativo: relato de experiência acerca da extensão universitária na atuação do PEJA/Araraquara

O relato apresentado enfoca uma análise acerca de alguns aspectos inicialmente detectados no processo de retomada das atividades do Programa de Educação de Jovens e Adultos (PEJA), no Campus da UNESP em Araraquara/SP. Situando a relevância das atividades de extensão universitária frente aos graves problemas que afetam a qualidade da escola e da educação no Brasil, em particular a Educação de Jovens e Adultos, e considerando que o enfrentamento dessa realidade deva se dar sob a perspectiva da formação articulada com a pesquisa, a reflexão feita busca apresentar o perfil dos alunos que se interessaram em participar do processo de reorganização do grupo de professores alfabetizadores, os passos iniciais nesse processo de formação de salas de aula e as manifestações e impressões manifestas por duas bolsistas integrantes do PEJA quanto às atividades que passaram a realizar, na atuação docente frente a uma sala de aula. Destacando pontos positivos e dificuldades detectadas, as análises empreendidas pelas participantes revelam o valor das atividades de extensão, intimamente relacionadas à pesquisa e à formação profissional, bem como dão pistas sobre elementos que poderiam enriquecer e engrandecer a formação inicial em cursos de licenciaturas.

Singular Value Decomposition and Ligand Binding Analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Significados e expectativas de crianças das camadas populares em relação à escolarização

Nowadays, we understand the childhood as a result of historical and social changes. This work aims to comprehend representations and expectations made by children from the popular classes in the initial years of Fundamentaql Education. We conducted a research with six students from a public school that attends children from urban popular layer's families. The research examines the meanings and representations of educational practices developed in the relationships established among teachers, students and families through their life stories. Among the results, we can say that the environment of differentiation in the school id perceived to the students because they introject teacher's representations about their performance. Scientific studies show that children crystallize a positive image of the shool when the speech and posture of the institution value and encourage learning. However, the students are challenged to produce better results in order to participate in extracurricular activities, which they are excluded todue indiscipline or learning difficulties. The mean of the schooling is highly influenced by the performance of students and also by the attitude of educators in the family and in the school. The theoretical review points out that when students have a good performance, the merit is attributed to stress and ease they have to acquire the learning contents. In other hand, struggling students or with a lag of content explains the academic problems stems from the lack of capacity and potential for acquisition of learning compatible with age, defining schooling as something necessary for training, but which is inaccessible in their life stories

Multicollinearity and financial constraint in investment decisions: a bayesian generalized ridge regression

This paper addresses the investment decisions considering the presence of financial constraints of 373 large Brazilian firms from 1997 to 2004, using panel data. A Bayesian econometric model was used considering ridge regression for multicollinearity problems among the variables in the model. Prior distributions are assumed for the parameters, classifying the model into random or fixed effects. We used a Bayesian approach to estimate the parameters, considering normal and Student t distributions for the error and assumed that the initial values for the lagged dependent variable are not fixed, but generated by a random process. The recursive predictive density criterion was used for model comparisons. Twenty models were tested and the results indicated that multicollinearity does influence the value of the estimated parameters. Controlling for capital intensity, financial constraints are found to be more important for capital-intensive firms, probably due to their lower profitability indexes, higher fixed costs and higher degree of property diversification.

Modelagem do aporte de sedimentos aplicada à bacia hidrográfica contribuinte da PCH Costa Rica (MS) e proposta de mitigação do assoreamento

Pós-graduação em Engenharia Mecânica - FEG

Avaliação técnica e econômica de um biodigestor de fluxo tubular: estudo de caso do modelo implantado na etec "orlando quagliato" em Santa Cruz do Rio Pardo, SP

Pós-graduação em Agronomia (Energia na Agricultura) - FCA