Características químicas de serragem de espécies nativas e exóticas sob condições de plantio.

Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso

Caracterização dos solos em áreas manejadas com bacurizeiros nativos nas mesorregiões do Nordeste paraense e Marajó.

A distribuição geográfica de bacurizeiros (Platonia insignis Mart.) é controlada por fatores naturais e antrópicos que contribuem para sua ocorrência e concentração de populações manejadas desta espécie, nas mesorregiões do Nordeste Paraense e Marajó. Com base nessa hipótese, este trabalho teve como objetivo a caracterização dos solos de sítios com bacurizeiros manejados nestas duas mesorregiões..

An Exact Approach to the Oscillator Radiation Process in an Arbitrarily Large Cavity

Starting from a solution of the problem of a mechanical oscillator coupled to a scalar field inside a reflecting sphere of radius $R$, we study the behaviour of the system in free space as the limit of an arbitrarily large radius in the confined solution. From a mathematical point of view we show that this way of facing the problem is not equivalent to consider the system {\it a} {\it priori} embedded in infinite space. In particular, the matrix elements of the transformation turning the system to principal axis, do not tend to distributions in the limit of an arbitrarily large sphere as it should be the case if the two procedures were mathematically equivalent. Also, we introduce "dressed" coordinates which allow an exact description of the oscillator radiation process for any value of the coupling, strong or weak. In the case of weak coupling, we recover from our exact expressions the well known decay formulas from perturbation theory.Comment: 27 page

New method to study stochastic growth equations: a cellular automata perspective

We introduce a new method based on cellular automata dynamics to study stochastic growth equations. The method defines an interface growth process which depends on height differences between neighbors. The growth rule assigns a probability $p_{i}(t)=\rho$ exp$[\kappa \Gamma_{i}(t)]$ for a site $i$ to receive one particle at a time $t$ and all the sites are updated simultaneously. Here $\rho$ and $\kappa$ are two parameters and $\Gamma_{i}(t)$ is a function which depends on height of the site $i$ and its neighbors. Its functional form is specified through discretization of the deterministic part of the growth equation associated to a given deposition process. In particular, we apply this method to study two linear equations - the Edwards-Wilkinson (EW) equation and the Mullins-Herring (MH) equation - and a non-linear one - the Kardar-Parisi-Zhang (KPZ) equation. Through simulations and statistical analysis of the height distributions of the profiles, we recover the values for roughening exponents, which confirm that the processes generated by the method are indeed in the universality classes of the original growth equations. In addition, a crossover from Random Deposition to the associated correlated regime is observed when the parameter $\kappa$ is varied.Comment: 6 pages, 7 figure

O pensamento cr?tico em ci?ncias no Brasil: um olhar para os livros did?ticos

The Science area of education needs to provide for contemporaneous individuals with a background that prioritizes not only scientific knowledge, but also the development of competences that make them prepared to act in society. In this context, it is important to consider the promotion of Critical Thinking (CT) as potential approach for capabilities development as problem solving, decision-making, reflection and criticality. Considering this importance was performed documental analysis on 8 Didactic Books (DB) of the Elementary School 7th grade, identifying the purpose of the proposed activities, as well as their potential for the capacity development of CT. We realize, with the analysis, diversity of activities on Science DB, being that the most recurrent were classified on Exploratory category, which confer the opportunity for the person get involved in the process, depending on the pedagogical routing used by the teacher on his activities. We observed also, the presence of activities classified as Reflective/Criticism, whom play a crucial role in the person formation, instigating himself to think, reflect and criticize. It was also noted the presence of more traditional activities tory in the Explanatory category, because it only intends to bring additional information to the content. However, the results were considered satisfactory to the Science teaching, so we recognize that exploratory activities (most common), if well measured, has potential for the students build their own knowledge and their capabilities of CT, which also shows that the most updated DB of Science has been improved its quality in the last years. The results express that the most current LDs of Science, do not have predominantly simplistic and traditional activities, such as those listed in the Informational category, but which are advancing in relation to the nature of the proposed activities. Considering that some teachers still have their pedagogical practice basically permeated by LD, the improvements observed in the activities represent an advance for teaching and learning in Sciences.A ?rea da educa??o em Ci?ncias precisa subsidiar os sujeitos contempor?neos com uma forma??o que priorize n?o somente os conhecimentos cient?ficos, mas tamb?m o desenvolvimento de compet?ncias que os tornem preparados para atuar em sociedade. Nesse contexto, consideramos a promo??o do Pensamento Cr?tico (PC) como uma abordagem em potencial para o desenvolvimento de capacidades como: resolu??o de problemas, tomada de decis?es, reflex?o e criticidade. Pensando nisso, realizamos uma an?lise documental em 8 Livros Did?ticos (LD) do 7? ano do Ensino Fundamental, identificando a natureza das atividades propostas, bem como o potencial das mesmas para o desenvolvimento das capacidades do PC. Percebemos, com a an?lise a diversidade de atividades presentes nos LD de Ci?ncias, sendo que as mais recorrentes foram classificadas na categoria Explorat?rias, as quais conferem a oportunidade do sujeito se envolver no processo, a depender do encaminhamento pedag?gico utilizado pelo professor nas atividades. Observamos tamb?m, a presen?a de atividades classificadas como Reflexivas/Cr?ticas, as quais desempenham um papel crucial na forma??o do sujeito, instigando-o a pensar, refletir e criticar. Verificamos ainda, a presen?a de atividades mais tradicionais, classificadas na categoria Informativas, pois apenas t?m o intuito de apresentar uma informa??o adicional ao conte?do. Contudo, consideramos os resultados satisfat?rios ao ensino de Ci?ncias, pois reconhecemos que as atividades explorat?rias (mais frequentes), se bem mediadas possuem potencial para que os sujeitos construam os seus pr?prios conhecimentos e suas capacidades de PC. Os resultados expressam que os LD de Ci?ncias mais atuais, n?o possuem predominantemente atividades simplistas e tradicionais, como as elencadas na categoria Informativas, vem avan?ando em rela??o ao car?ter das atividades propostas. Tendo em vista, que ainda alguns docentes t?m a sua pr?tica pedag?gica permeada basicamente pelo LD, as melhorias observadas nas atividades, representam um avan?o para o ensino e aprendizagem em Ci?ncias

Resultados do controle de desenvolvimento ponderal - Raça Gir - 1976/1984.

A Raça Gir. Controle de desenvolvimento ponderal. Considerações sobre os resultados do controle de desenvolvimento ponderal das Raças Gir e Gir variedade Mocha. Controle ponderal das Raças Gir e Gir variedade mocha a nível nacional. Categorias de registro. Sexo. Regime alimentar. Ano de nascimento. Estação de nascimento. Mérito dos reprodutores. Controle ponderal da Raça Gir a nível de estado.bitstream/item/131353/1/resultados-do-controle-de-desenvolvimento-76-84.pd