Formação de professores: perspectivas docentes para a construção da cidadania intercultural

Propomos neste artigo uma reflexão sobre as possibilidades de uma educação pautada pelos princípios da interculturalidade, no sentido de uma cidadania ativa, crítica e participativa. Para tanto, discutimos as contribuições de duas pesquisas realizadas por investigadores vinculados ao Grupo de Investigación en Educación Intercultural (GREDI Universidade de Barcelona). Os critérios que orientaram tal escolha se pautaram: por oferecer um enfoque privilegiado na formação de professores para a cidadania intercultural; pelo desenvolvimento de um programa de formação para a cidadania intercultural; pelo contexto de execução da pesquisa marcado por características multiculturais e pela atualidade do trabalho. Para além das estratégias consagradas de coleta de dados na pesquisa em educação, comumente as pesquisas produzidas no âmbito do GREDI apresentam propostas de intervenção traduzidas em programas, projetos e ações que são acompanhadas, avaliadas, analisadas e problematizadas conforme preconizam os princípios da metodologia adotada como referência. Assim, nosso objetivo centra-se em compreender como se desencadeiam os processos de construção de cidadania intercultural nas práticas educativas propostas pelos pesquisadores em suas investigações.

Projeto e construção de um bioreator para síntese orgânica assimétrica catalisada por saccharomyces cerevisiae (fermento biológico de padaria)

A model for the construction of a simple and cheap apparatus to be used as bioreactor for reactions catalyzed by baker's yeast (Saccharomyces cerevisiae) is described. The bioconversion and separation of cells from products and residual substrates are obtained at the same time. The reactions carried out in this type of reactor are faster than those catalyzed by immobilized cells. Yeast cells can be cultivated in this bioreactor operating with cell recycling at appropriated conditions using glucose and other nutrients.

Construção de equipamentos de refrigeração que permitem trabalhar com temperaturas de -40ºC ou -60ºC

In this article we describe the construction of two cooling systems with an immersion probe which will allow one to work at temperatures of either -40ºC or -60ºC. The two systems were constructed with readily available components and have been used daily for the last year in our laboratory to carry out reactions at low temperature or to cool down traps of vacuum pumps, reducing our need of dry-ice or liquid nitrogen.

Ultramicroeletrodos. Parte II: construção e aplicações

This work describes the techniques of construction and several applications of ultramicroelectrodes in electrochemistry and electroanalytical chemistry. Disc shaped UME are produced by embedding metal wires on insulating materials such as glass or epoxy resin. In the field of electrochemistry, UME have been applied in studies of the hydrogen evolution reaction and the electrocrystallization of metals. The negligible values of sensibility for ohmic drop and the enhanced mass transport rate by spherical diffusion are the main advantages of UME in these applications. New important conclusions regarding the phenomena under study were drawn from the experimental results. The applications in electroanalytical chemistry involved the determination of contaminants such as heavy metals and nitrites in natural waters and food products. The use of UME requires little sample manipulation and, in general, no need for oxygen removal or the addition of supporting electrolytes.

Construção e avaliação de um eletrodo tubular sensível ao íon hidrogênio como detector em sistemas de análise em fluxo

The construction of a tubular hydrogen ion-selective potentiometric electrode without inner reference solution, based on the tridodecylamine (TDDA) ionophore, and its evaluation in a flow system are described. TDDA was dissolved in 2-nitrophenyl octyl ether, dispersed in a PVC membrane and applied directly to a conducting support which consisted of an epoxy resin and graphite mixture. The electrode was designed with a tubular geometry to effort facilities to be coupled as part of a flow injection network. The main working characteristics such as response time, linear pH range, selectivity and life time were evaluated and compared with those obtained which a conventionally shaped electrode based on the same sensor. The electrode showed a slope of 51-52 mV dec-1 within a linear pH range from 4.0 up to 12.0.

Construção de uma célula espectroeletroquímica termostatizada e sua aplicação para estudar polímeros eletrocrômicos

The construction of a temperature controllable spectroelectrochemical cell is described. Its use in the analysis of the thermodynamic and structural parameters of the electrochromic process of poly(3-methyl thiophene) in the temperature range between -40ºC and 60ºC is given as an example of application.

Construção e otimização de um sistema para produção e aplicação de ozônio em escala de laboratório

This paper shows the assembly of an ozonization system to be used in laboratory scale, mainly to study effluent treatability. The system is simple, practical and provides easy acquisition of data when interfaced to a microcomputer. The performance of ozone generation and K La values are also described.

Construção de modelos para ilustração de estruturas moleculares em aulas de química

This paper describes the construction of a kit of molecular model for illustration of molecular structure in chemical class using cheap materials. The atoms were represented by plastic spheres and the bonds between the atoms were made from plastic straws which were cut in the required length using a scale of 1.6 cm corresponding to 100 pm. Examples of adaptations made in this kit for didactical application are given.