Reproductive site selection in the leaf-frog Phyllomedusa azurea Cope, 1862 (Anura: Hylidae) in altered areas of the Brazilian Cerrado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structural and Electrochemical Properties of Lutetium Bis-Octachloro-Phthalocyaninate Nanostructured Films. Application as Voltammetric Sensors

Thin films of the bis[2,3,9,10,16,17,23,24-octachlorophthalocyaninate] lutetium(III) complex (LuPc2Cl32) have been prepared by the Langmuir-Blodgett and the Langmuir-Schaefer (LS) techniques. The influence of the chlorine substituents in the structure of the films and in their spectroscopic, electrochemical and sensing properties has been evaluated. The pi-A isotherms exhibit a monolayer stability greater than the observed in the unsubstituted analogue (LuPc2), being easily transferred to solid substrates, also in contrast to LuPc2. The LB and LS films present a linear growth forming stratified layers, monitored by UV-VIS absorption spectroscopy. The latter also revealed the presence of LuPc2Cl32 in the form of monomers and aggregates in both films. The FTIR data showed that the LuPc2Cl32 molecules present a non-preferential arrangement in both films. Monolayers of LB and LS were deposited onto 6 nm Ag island films to record surface-enhanced resonance Raman scattering (SERRS), leading to enhancement factors close to 2 x 10(3). Finally, LB and LS films deposited onto ITO glass have been successfully used as voltammetric sensors for the detection of catechol. The improved electroactivity of the LB and LS films has been confirmed by the reduction of the overpotential of the oxidation of catechol. The enhancement of the electrocatalytic effect observed in LB and LS films is the result of the nanostructured arrangement of the surface which increases the number of active sites. The sensors show a limit of detection in the range of 10(-5) mol/L.

Peat humic substances enriched with nutrients for agricultural applications: competion between nutrients and non-essential metals present in tropical soils

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O ensino de redação em sites: diálogos em rede

We know that studies on reading and writing take place within the Linguistic for several decades and, with de computer, the language entered the network and this is opening a learning space for writing classes, no more reduced to a classroom but expanded to a universe that has no geographical boundaries, namely de Internet. Our research fits into this context and is part of the project The discourse on writing practices in contemporary Brazilian media: the art making, the pedagogical practice, and the production of meaning to develop discourse analysis on the practice of writing on sites dedicated to teaching and learning of this practice. The main objective of this research is to investigate the relationship between school attendance of redaction - made here as discourse gender, as you know Bakhtin - and the discourse of the sites that constitute our corpus. We set out the hypothesis that the sites are intended for the teaching/learning of writing seeking to create virtually teaching imaginarily conditions similar to those that exist in school attendance of the Portuguese language. We are interested in, therefore, observe, discursively, as the image is created of the interlocutors to which they are intended considering that the enunciators are not in front of those who occupy the place of real students, because they are virtual students. We, too, to know as the gender class manifested itself in those sites, as these sites dialogue with the face-to-face class in relation to ideology, the function of the teacher, the conception of language and writing. The constitution of the corpus was from search tools on the internet. The sites that we analyzed were: alunosonline.com.br, brasilescola.com.br, coladaweb.com.br, guiadoestudante.com.br, infoescola.com.br, mundoeducação.com.br, mundovestibular.com.br, português.com.br, professorjuscelino.com.br and redaçãodissertativa.com.br. The selection was qualitative, considering the...