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Na educação a distância, a mediação pedagógica ocorre por meio de diversas tecnologias. Nesse contexto, as lives apresentam-se como um recurso que possibilita a melhor simulação de uma situação dialógica semelhante à da sala de aula. Com base na experiência da Universidade Virtual do Estado de São Paulo, este trabalho propõe compreender a relação entre a expectativa dos alunos com as ofertas das lives e as estratégias dos facilitadores para tornar essa ferramenta relevante no processo de aprendizagem. A partir dos dados obtidos analisados quantitativamente, notou-se a necessidade da combinação de práticas, ação pedagógica e uso das tecnologias mais adequadas considerando o conteúdo e o conhecimento que se quer construir, corroborando a adoção do paradigma TPACK.

A derivation of the sol-gel-dip-coating deposition technique is proposed, where the precursor solution exhibits two separated liquid phases, reaching an equilibrium state in a heterogeneous solution. Structural, optical and photocatalytic properties of TiO 2 films grown from the proposed two phases method are shown and discussed, along with the properties of films deposited when the top phase present distinct lengths, which are observed through SEM images and optical transmittance spectra. The dominant crystalline phase is anatase for all the films prepared. Films are tested towards their efficiency for photocatalysis, using methylene blue as dye degradation agent. It has been found that films deposited through the two phase method are more efficient on the photocatalyitic degradation of methylene blue.

The photocatalytic activity and stability of TiO 2 thin films deposited by reactive sputtering were evaluated through many cycles of aqueous methylene blue solutions photodegradation. Tests were performed in TiO 2 films deposited onto silica, silicon, and lanthanum aluminate substrates under UV light irradiation. The dye degradation was determined using the optical absorbance spectra at preestablished exposure times. After 16 cycles of reaction, 180 minutes each, no systematic losses in the photocatalytic activity were observed in the samples. The best activity was observed on films deposited onto silica glass. The results indicate that the TiO 2 samples deposited by the sputtering technique are stable concerning the UV degradation of methylene blue.

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