Analyses of the modifications in the pi circuits for inclusion of frequency influence in transmission line representation

In this article, it is represented by state variables phase a transmission line which parameters are considered frequency independently and frequency dependent. It is analyzed what is the reasonable number of pi circuits and the number of blocks composed by parallel resistor and inductor in parallel for reduction of numerical oscillations. It is simulated the numerical routine with and without the effect of frequency in the longitudinal parameters. Initially, it is used state variables and pi circuits representing the transmission line composing a linear system which is solved by numerical routines based on the trapezoidal rule. The effect of frequency on the line is synthesized by resistors and inductors in parallel and this representation is analyzed in details. It is described transmission lines and the frequency influence in these lines through the state variables.

Control of parasitic infections among school children in the peri-urban area of Botucatu, Sao Paulo, Brazil

The prevalence of intestinal parasitosis was investigated in a primary school located in Rubiao Junior, a peri-urban district of Botucatu, Sao Paulo state, Brazil, in order to assess the effect of treatment and practical measures of prophylaxis in the control of parasitic infections among 7-to-18-year-old school children of a low socio-economic status. The first series of parasitological examinations included 219 school children, of which 123 (56.1%) were found to be infected with one or more parasite species. Eighty-four children carrying pathogenic parasites were submitted to various anti-parasitic treatment schedules. We re-evaluated 75 (89%) students after 4 to 6 months postchemotherapy. The results indicate that the combination of treatment with prophylactic measures has been successful in the control of parasitic infections, since reinfection rates were generally low (≤5.3%), except for Giardia lamblia infections (18.6%), and a marked reduction on the prevalence rates was observed with a significant percentage of cure (≤73.1%) in children infected with most parasite species. The reasons for the apparent failure in the control of infections caused by Hymenolepsis nana and Strongyloides stercoralis are discussed.

Ergonomic research applied in the design of pre-school furniture: The Mobipresc 3.6

This research describes the application of a scientific and technological model of Ergonomics in the design of pre-school furniture. The constant presence of the desk in early education and its influence in the relationship between the user and his educational environment determined the necessity of this project. The pre-school desk was considered as a work station, where the joint aspects of education and child anthropometry substantiate the problem. The review of the Historical application of Ergonomics in the Design of children's products consolidated the importance of this report. The development of ergonomic research, characterised by investigations of the Brazilian child's Anthropometry Data and Biomechanical Features, resulted in dimensional parameters of the user and physical characteristics of the present furniture. These elements, together with a comprehension of activities and needs in the pre-school, were connected with aspects of bibliographical revision to result in a series of recomendations for design. Through the methods of Ergonomic Design, a new proposal for the pre-school desk was developed, denominated Mobipresc 3.6.

The Didactic Transposition of the Photoelectric Effect in High School Brazilian Physics Textbooks

É notório que o livro didático desempenha um papel fundamental na prática pedagógica da maioria dos professores de Física constituindo importante fonte de referência para professores e estudantes. Ao mesmo tempo representa a memória impressa das demandas e paradigmas de ensino, e procura atender às exigências prescritas na legislação e diretrizes, de uma determinada localidade e período. Atualmente, a inserção de Física Moderna e Contemporânea no currículo do Ensino Médio brasileiro está entre as prioridades, preconizando, entre. outros, o ensino do efeito fotoelétrico, em função da relevância do fenômeno ao corroborar a interpretação corpuscular da natureza da luz, e o consequente laureio de Albert Einstein com o Prêmio Nobel. Estudos realizados apontam que muitos dos livros didáticos apresentam a história do efeito fotoelétrico de maneira superficial ou errônea, e expõem incorretamente a função trabalho e o conceito de fóton (Klassen, 2011). Tendo em vista o exposto, objetivamos analisar como ocorre a apresentação do efeito fotoelétrico especificamente em dez coleções didáticas brasileiras aprovadas pelo Programa Nacional do Livro Didático do Ensino Médio 2012 do governo federal, tendo como aporte teórico as considerações de Yves Chevallard (Brockington e Pietrocola, 2005). Procuramos resposta para a seguinte pergunta: Quais são as transposições ocorridas na apresentação do efeito fotoelétrico (saber sábio) para se tornar o saber a ensinar em materiais escolares? Nossa análise centrou-se no processo de descontextualização, entendido como o processo pelo qual o saber sábio passa para que seja ensinável, sendo necessário que seja arrancado de seu contexto original, ou seja, o seu processo histórico.

Particle Physics in the teaching practice of the participants of the School of Physics CERN

A atualização dos currículos escolares e, em especial, a inserção de assuntos de física moderna e contemporânea já foram defendidos com justificativas satisfatórias, tanto por professores em atividade escolar como por pesquisadores da área de ensino de física. Entre os assuntos que deveriam ser discutidos encontramos a Física das Partículas Elementares. O ensino deste tópico é justificado pelo fato dele permitir a discussão: a) de uma nova visão de mundo; b) de uma visão mais adequada da ciência; c) da reinterpretação da Física Clássica; d) da dinâmica da Ciência e seu desenvolvimento; e) da contribuição dos diversos cientistas; f) do papel da experimentação; g) do investimento financeiro e cooperativo de diversos países e pesquisadores. No entanto, para que a inserção de assuntos de física moderna e contemporânea ocorra de maneira eficiente é necessária a atualização dos professores que já estão em docência escolar, bem como uma formação adequada daqueles que estão em processo de formação inicial. Neste sentido, desde 2010 a Sociedade Brasileira de Física realiza anualmente a Escola de Física do CERN, na qual participam professores brasileiros de física de escolas públicas do Ensino Médio. Nesta escola são desenvolvidas aulas sobre física de partículas, sessões experimentais e visitas aos laboratórios do CERN. Perante isso, investigamos como os professores participantes da Escola de Física do CERN abordam a física de partículas em suas aulas após participarem dela.

The interactive whiteboard in primary school: a case study of a brazilian district school

Interactive whiteboards (IWB) consist of a set of technological equipment organized in order to fulfill a specific task, enabling the development of didactic activities. Because they are associated to computers’ potentiality, interactive whiteboards can provide bigger interactivity between: teacher and students, students and content, and among students. This work’s main objective is to present some of the results yielded from a research related to the way students perceive interactive whiteboards in the classroom. In order to analyze the IWB usage dynamics, some educational applications in the field of mathematics were applied in the 3rd grade of elementary school. Aside from observation, video recordings were made and students were interviewed about the interactive whiteboard, in order to understand how these students observe and engage with the technological tool. IWB do not transform classroom’s reality by themselves, however, their physical presence and usage amount to external reinforcement can change student’s behavior positively.