Angela Martins

Characterization of the acidity of Al- and Zr-pillared clays

The surface acidic properties of pillared clays (PILCs) with Al or Zr oxide pillars (prepared from a natural Portuguese smectite and a synthetic Laponite), and of a protonic NaHY zeolite, were studied by two methods: pyridine adsorption followed by infrared (IR) spectroscopy, and the catalytic transformation of 1-butene. The results of the pyridine adsorption revealed that all the pillared clays studied have mainly Lewis-type acidity, the exception being the clay pillared with Zr oxide, obtained from natural smectite, which also presents a significant number of Brönsted acid sites. The results of 1-butene transformation showed that the pillared clays exhibit catalytic properties similar to those of the protonic Y zeolite. The acid character of the solids was confirmed by the values of the cis/trans 2-butene isomers ratio. At short reaction times, product distribution showed that the main reaction is oligomerization, followed by cracking. After 15 min the products are mainly the linear isomers, cis and trans-2-butene, showing that the majority of the catalytic active sites, are already poisoned after 15 min of reaction. The particular behaviour of Laponite intercalated with Al oxide pillars is discussed. The IR spectra of the pyridine adsorbed on the fresh samples and after the catalytic assays, revealed that Lewis acid sites behave as active sites for 1-butene catalytic transformation. The consistency between the results of the two complementary techniques used for the characterization of the acidity of the solids was proved.

n-Hexane hydroisomerisation over bifunctional Pt/MCM-22 catalysts. Influence of the mode of Pt introduction

Three different methods were used to introduce 1.0 wt.% of Pt in bifunctional Pt/MCM-22 zeolite catalysts: ion exchange with Pt(NH 3 ) 4 2+ , incipient wetness impregnation with PtCl 6 H 2 and mechanical mixture with Pt/Al 2 O 3 . The Pt dispersion was estimated by transmission electron microscopy and the hydrogenating activity with toluene hydrogenation at 110°C. From these experiments, it can be concluded that with the ion exchanged sample, platinum was located within the inner micropores and on the outer surface, whereas with the impregnated one, platinum was essentially on the outer surface under the form of large particles. With all the samples there is a fast initial decrease in the activity for n-hexane hydroisomerisation at 250°C. With exchanged and impregnated samples, this decrease is followed by a plateau, the activity value being then higher with impregnated sample. For the sample prepared by mechanical mixture a continuous decrease in activity can be observed. All these differences can be related with the distinct locations of Pt.

A produção científica sobre avaliação educacional e gestão de sistemas e de escolas: o campo da questão entre 2000 e 2008

The text examines academic productions that focus on possible relationships between school management and evaluation, based on dissertations and theses, journal articles and proceedings from Associacao Nacional de Pos-Graduacao e Pesquisa em Educacao (Anpae), in a total of 25 documents. The focus here deepened originated in the State of Acre on the management, autonomy and functioning of collegiate bodies in public school systems which covered the period between the years 2000 and 2008, and gathered 735 documental sources. From the identification of the agglutinated thematic axes in question, the text aims to clarify contributions to the theoretical-methodological searches of that understanding, as well as to point out any possible subsidies for school managers and networks. It was found that, although still incipient, investigations that have dedicated themselves to analyze the relationship between large-scale assessment and school management tend to increase in a short period of time, in view of the prominence that the theme has been conquering in political guidelines in the field of education.O texto analisa producoes academicas que exploram possiveis relacoes entre gestao escolar e avaliacao, com base em dissertacoes e teses, artigos de periodicos e anais da Associacao Nacional de Pos-Graduacao e Pesquisa em Educacao (Anped) e da Associacao Nacional de Politica e Administracao da Educacao (Anpae), totalizando 25 documentos. O foco aqui aprofundado originou-se de Estado da Arte sobre gestao, autonomia e o funcionamento de orgaos colegiados em escolas publicas, que abrangeu o periodo entre os anos de 2000 a 2008 e reuniu 753 fontes documentais. A partir da identificacao de eixos tematicos aglutinadores da producao em pauta, o texto busca explicitar contribuicoes teorico-metodologicas das pesquisas para compreensao da referida tematica, bem como apontar eventuais subsidios para gestores de escolas e de redes. Verificou-se que, embora ainda incipiente, investigacoes que se dedicam a analisar as relacoes entre avaliacoes em larga escala e gestao escolar tendem a aumentar em curto espaco de tempo, tendo em vista a centralidade que o tema vem conquistando nas diretrizes politicas da area da educacao.

Isomerization of n-hexane on bifunctional catalysts Pt/HBEA and Pt/HMCM-22 with rare earth elements

The influence of rare earth (RE) elements La, Nd, and Yb was studied on the transformation of n-hexane using two catalysts with different porous structures, HBEA and HMCM-22. The zeolites were submitted to ion exchange with rare earth nitrate solutions of La, Nd and Yb, followed by platinum introduction. Platinum was characterized by Temperature Programmed Reduction (TPR-H 2 ) and by toluene hydrogenation. Pt/HBEA samples show higher hydrogenation activities than Pt/HMCM-22. In transformation of n-hexane both zeolites present high selectivity for the isomerization reaction. The presence of RE elements in Pt/HBEA increases the selectivity for di-branched isomers. Pt/HMCM-22 shows low selectivity in di-branched isomers due to shape selectivity effects provoked by the introduction of RE elements in the pores of this zeolite.

Toluene methylation over pillared clays with Al, Zr and Al/Zr oxides

Pillared clays (PILCs), with Al, Zr and Al/Zr oxides, obtained from a natural montmorillonite from Benavila (Portugal), were investigated in terms of their structure (XRD), texture (N 2 and toluene adsorption), acidity (pyridine chemisorption) and catalytic performances on methylation of toluene. Zr content reflects on the d 001 values and on the acidity of PILCs, that present, besides Lewis sites, also Bronsted acid sites. All the solids showed activity to toluene alkylation revealing that, even the Bronsted acidic properties that proceed only from the clay sheets are enough to promote alkylation. A mixture of xylenes (XY) was obtained as the main reaction products, and the isomers distribution followed generally the order m ≥ o > p . Trimethylbenzenes (TMB) and ethyltoluenes (EtT) were also found, and on all the samples the selectivities were S xy >> S TMB > S EtT .

Improved cyclohexane oxidation catalyzed by a heterogenized Iron (II) complex on hierarchical Y zeolite through surfactant mediated technology

The hydrotris (pyrazol‐1‐yl) methane iron (II) complex [FeCl2(Tpm)] [Tpm=HC(C3N2H3)3] was successfully immobilized, by the incipient wetness impregnation method, in parent and hierarchical Y zeolite modified through surfactant mediated methodology using different bases (NH4OH, NaOH or TPAOH). The catalytic performance and recyclability of supported Fe complex was evaluated in the oxidation of cyclohexane with hydrogen peroxide to cyclohexanol and cyclohexanone under mild conditions and two distinct behaviors were observed: using commercial Y and modified Y with NaOH the complex is anchored mainly at the outer surface of the zeolite supports, resulting in high lixiviation after the first catalytic cycle. When NH4OH and TPAOH are used during the zeolite treatments the particular textural parameters exhibited by these two supports are able to effectively retain the complex molecules, resulting in a high recyclability observed after three consecutive cycles, especially when NH4OH treated zeolite was used as support.

A gestão da educação básica na esfera municipal: papel do governo federal na indução de programas

Introdução O artigo apresenta resultados de estudo que teve por objetivo analisar o potencial de iniciativa do governo federal para induzir inter-relações entre os governos municipais com vistas à promoção da gestão democrática da educação, por meio do Prêmio Inovação em Gestão Educacional. O referido Prêmio, instituído em 2006, se constitui em uma das iniciativas do Laboratório de Experiências Inovadoras em Gestão Educacional − fruto de parceria entre o Instituto Nacional de Estudos e Pesquisas Educacionais Anísio Teixeira e a Secretaria de Educação Básica do Ministério da Educação (Inep/SEB/MEC 1 ) −, que se propõe, dentre outras ações, a registrar e a disseminar experiências inovadoras de gestão municipal, por meio do Banco de Experiências em Gestão Municipal da Educação. Estruturado em três seções, o texto registra 2 , inicialmente, uma caracterização do Laboratório de Experiências Inovadoras em Gestão Educacional e do Banco de Experiências. Em seguida, analisa a noção de inovação assumida pelo governo federal, cotejando-a com a literatura que trata do tema, com base na apreciação de projetos de municípios paulistas, que correspondem a dez dentre as cinquenta e nove experiências brasileiras, constantes no referido Banco, inscritas nos anos 2006 e 2008. Por fim, problematiza o delineamento do próprio Laboratório, bem como a iniciativa de premiação de projetos isolados como forma de estimular a gestão democrática do ensino. Como perspectiva metodológica, tomou-se como referência a abordagem que enfatiza a relevância de se analisar instrumentos e planos normativos que norteiam a ação pública, pois estes não são neutros, expressam uma visão de mundo e de conhecimento concatenados em ação de governo. Registre-se que na análise de políticas podemos levar em conta três dimensões: a institucional, que se refere ao sistema jurídico e à estrutura do sistema político-administrativo; os processos políticos nos quais ocorrem negociações em torno dos objetivos e das escolhas para estruturação das agendas; finalmente, a terceira diz respeito à concretização de programas e projetos.

The scientific literature on educational assessment and management systems and schools: the field of matter between the years 2000 - 2008

The text examines academic productions that focus on possible relationships between school management and evaluation, based on dissertations and theses, journal articles and proceedings from Associacao Nacional de Pos-Graduacao e Pesquisa em Educacao (Anpae), in a total of 25 documents. The focus here deepened originated in the State of Acre on the management, autonomy and functioning of collegiate bodies in public school systems which covered the period between the years 2000 and 2008, and gathered 735 documental sources. From the identification of the agglutinated thematic axes in question, the text aims to clarify contributions to the theoretical-methodological searches of that understanding, as well as to point out any possible subsidies for school managers and networks. It was found that, although still incipient, investigations that have dedicated themselves to analyze the relationship between large-scale assessment and school management tend to increase in a short period of time, in view of the prominence that the theme has been conquering in political guidelines in the field of education.O texto analisa producoes academicas que exploram possiveis relacoes entre gestao escolar e avaliacao, com base em dissertacoes e teses, artigos de periodicos e anais da Associacao Nacional de Pos-Graduacao e Pesquisa em Educacao (Anped) e da Associacao Nacional de Politica e Administracao da Educacao (Anpae), totalizando 25 documentos. O foco aqui aprofundado originou-se de Estado da Arte sobre gestao, autonomia e o funcionamento de orgaos colegiados em escolas publicas, que abrangeu o periodo entre os anos de 2000 a 2008 e reuniu 753 fontes documentais. A partir da identificacao de eixos tematicos aglutinadores da producao em pauta, o texto busca explicitar contribuicoes teorico-metodologicas das pesquisas para compreensao da referida tematica, bem como apontar eventuais subsidios para gestores de escolas e de redes. Verificou-se que, embora ainda incipiente, investigacoes que se dedicam a analisar as relacoes entre avaliacoes em larga escala e gestao escolar tendem a aumentar em curto espaco de tempo, tendo em vista a centralidade que o tema vem conquistando nas diretrizes politicas da area da educacao.

La producción científica sobre evaluación educacional y gestión escolar y de sistemas: su ámbito entre 2000 y 2008

The text examines academic productions that focus on possible relationships between school management and evaluation, based on dissertations and theses, journal articles and proceedings from Associacao Nacional de Pos-Graduacao e Pesquisa em Educacao (Anpae), in a total of 25 documents. The focus here deepened originated in the State of Acre on the management, autonomy and functioning of collegiate bodies in public school systems which covered the period between the years 2000 and 2008, and gathered 735 documental sources. From the identification of the agglutinated thematic axes in question, the text aims to clarify contributions to the theoretical-methodological searches of that understanding, as well as to point out any possible subsidies for school managers and networks. It was found that, although still incipient, investigations that have dedicated themselves to analyze the relationship between large-scale assessment and school management tend to increase in a short period of time, in view of the prominence that the theme has been conquering in political guidelines in the field of education.O texto analisa producoes academicas que exploram possiveis relacoes entre gestao escolar e avaliacao, com base em dissertacoes e teses, artigos de periodicos e anais da Associacao Nacional de Pos-Graduacao e Pesquisa em Educacao (Anped) e da Associacao Nacional de Politica e Administracao da Educacao (Anpae), totalizando 25 documentos. O foco aqui aprofundado originou-se de Estado da Arte sobre gestao, autonomia e o funcionamento de orgaos colegiados em escolas publicas, que abrangeu o periodo entre os anos de 2000 a 2008 e reuniu 753 fontes documentais. A partir da identificacao de eixos tematicos aglutinadores da producao em pauta, o texto busca explicitar contribuicoes teorico-metodologicas das pesquisas para compreensao da referida tematica, bem como apontar eventuais subsidios para gestores de escolas e de redes. Verificou-se que, embora ainda incipiente, investigacoes que se dedicam a analisar as relacoes entre avaliacoes em larga escala e gestao escolar tendem a aumentar em curto espaco de tempo, tendo em vista a centralidade que o tema vem conquistando nas diretrizes politicas da area da educacao.

Study of Metal NH3 Interfaces (Metal = Cu, Ni, Ag) Using Potentiostatic Curves.

Students determine kinetic and thermodynamic parameters of different metal�solution interfaces. These parameters are obtained from potentiostatic curves using the Tafel and the Arrhenius equations. The work involves the variation of type of metal, solution concentration, and temperature. The results allow the discussion of the polarizability, transfer coefficient, and activation energy of the processes, as well as the differences between them.