Resumo Descreve-se neste trabalho resultados recentes, obtidos com 32 alunos do Ensino Médio a respeito de concepções alternativas sobre corrente elétrica em circuitos simples. Utilizou-se um teste de 14 itens elaborado no IF-UFRGS e validado após aplicação a alunos de engenharia da mesma universidade, em 1989. No presente experimento, 7 alunos foram selecionados para entrevistas clínicas, a partir do padrão de respostas no teste escrito. Os resultados do teste escrito foram comparados àqueles obtidos na UFRGS e analisados no contexto da literatura internacional pertinente ao tema. Confirmou-se a recorrência de concepções alternativas já amplamente relatada por autores de diversos países em diferentes continentes. As entrevistas clínicas permitiram uma investigação mais detalhada deste fenômeno e sinalizaram a necessidade de novas abordagens didáticas no ensino de circuitos elétricos.

Abstract This paper describes recent results obtained with 32 students from the Middle School regarding alternative conceptions about electric current in simple circuits. A 14-item test developed at IF-UFRGS was used and validated after application to engineering students from the same university in 1989. In the present experiment, 7 students were selected for clinical interviews, from the standard of answers in the written test. The results of the written test were compared to those obtained at UFRGS and analyzed in the context of the international literature relevant to the topic. The recurrence of alternative conceptions, as observed in the present investigation, has already been widely reported by authors from different countries on different continents. The clinical interviews allowed a more detailed investigation of this phenomenon and signaled the need for new didactic approaches in the teaching of electrical circuits.

Titanium oxides such as rutile and anatase, are materials that stand out for exhibiting properties that act in biomedical and photocatalytic applications, among others. It is extreme importance to idealize new techniques that produce such compounds, being indispensable the improvement of characterizations for these materials. For this purpose, titanium comercially pure (CP) grade II cylindrical samples were oxidized ionically using titanium cage electric shields, oxidized at 350 ° C in 3 and 8 hours. Through Grazing Incidence X-ray Diffraction (GIXRD) analysis, was observed on the surface of the treated samples the formation of a TiO2 film with the anatase, rutile and brookite phases, the latter phase cited being difficult to produce in conventional thermochemical treatments. All samples treated showed a significant increase in wettability using distilled water. The higer value was for the sample with a 8 hours treatment time, in which this condition presented phases with greater intensity in the analysis of GIXRD