Advanced Supported and Non Supported Polyoxometalate Materials for Oxidative Catalytic Reactions

In this work, new heterogeneous catalysts based on mesoporous silica nanoparticles (MSNPs) with different cations of ionic liquids (ILs) covalently bonded to their surface, 1-butyl-3-methylimidazolium ([C4MIM]+), 1-butylpyridinium ([C4Py]+) and tetrabutylammonium ([N4,4,4,4]+), and with the polyoxometalate (POM) derived from phosphomolybdic acid ([H(3-x)PMo12O40]x-) as anions were prepared. Their analogous homogeneous compounds were also prepared for comparison (POM-ILs), [N4,4,4,4]3[PMo12O40], [C4MIM]3[PMo12O40] and [C4Py]3[PMo12O40]. The catalysts were characterized by elemental analysis, in solution (1H and 31P) and solid-state (13C and 31P) NMR spectroscopy, DLS (for the silica nanoparticles), SEM, TEM, EDS, X-ray fluorescence spectroscopy, FTIR spectroscopy and ICP-MS. The homogeneous catalysts were applied in the preliminary oxidation reactions of two lignin model compounds, cinnamyl alcohol and guaiacol, varying the reaction conditions (time, presence of hydrogen peroxide and use of conventional heating or microwave heating). The results obtained were characterized by solution 1H NMR spectroscopy. The oxidation of cinnamyl alcohol seems to be promissory using microwave heating process in comparison to conventional process. All catalysts prepared were also applied in the oxidative desulfurization reactions of a multicomponent model diesel, composed by 1-benzothiophene, dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene in order to study the performance of each catalyst in the removal of sulfur compounds present in fuels. This part of the study was performed in Faculdade de Ciências from Universidade do Porto, and the catalytic performance was evaluated by gas chromatography. The heterogeneous catalysts had the most promising results, in particular MSNPs-[N4,4,4,4]POM achieving 100% of total desulfurization after only 2 hours. Its recycling ability was evaluated for three consecutive cycles and it was observed an increase of the catalytic efficiency for the second and third cycles reaching the complete desulfurization of the model diesel after just 1h instead of the 2h. The catalysts with cation tetrabutylammonium had the best results in both heterogeneous and homogeneous catalysis in comparison to the other two catalysts. In general, all catalysts tested had interesting results

Benefícios cognitivos do treino musical em jovens

Este estudo teve como objetivo principal estudar e analisar diferenças cognitivas entre o estudante profissional de música em relação ao estudante de ensino regular, tendo em conta os dois ambientes distintos em que estes estão inseridos. A pesquisa foi elaborada numa amostra de estudantes de terceiro ciclo e ensino secundário em duas escolas da Beira Interior, sendo uma escola de cariz profissional e outra de cariz regular. Fizeram parte da amostra 190 alunos, do sexo feminino (n=84) e masculino (n=106), oriundos de várias localidades do país rurais e urbanas com idades compreendidas entre os 12 e 22 anos. Para elaborar a pesquisa foram utilizados dois instrumentos, um questionário sociodemográfico e a Bateria de Provas de Raciocínio (BPR), de Almeida (2009), que consiste em 5 provas de raciocínio (abstrato, numérico, verbal, espacial e mecânico). Os resultados sugerem que no geral os estudantes de música apresentam melhores capacidades de raciocínio em todas as provas de raciocínio que lhes foram apresentadas, sendo que apenas no que concerne ao raciocínio verbal os resultados, mesmo sendo superiores, não foram significativos. Pôde observar-se também, que tanto o começo precoce dos estudos musicais como a maior intensidade de treino musical (traduzida em mais tempo de dedicação ao estudo musical) são indicadores de melhores resultados em termos de raciocínio a um nível geral, por conseguinte de melhores capacidades cognitivas. Pudemos também, constatar que quanto maior é a experiência musical do individuo melhor será o seu desempenho cognitivo. Constatámos também a superioridade cognitiva dos alunos de música cujo instrumento principal é de coradas em detrimento de outro tipo de instrumentos. Foi destacada também a superioridade cognitiva dos músicos do sexo feminino em relação aos do sexo masculino tanto a nível geral como espacial. Não ficou provada a vantagem da utilização da prática musical enquanto atividade extracurricular, posto os estudantes de ensino regular que praticam atividades musicais obterem resultados inferiores aos demais estudantes regulares

Empresas cidadãs e comunicação: uma nova era no âmbito da responsabilidade social corporativa

Procurar-se-à, no presente artigo, defender uma visão da Responsabilidade Social Corporativa que esteja muito para além de uma qualquer ideia de “caridade” ou “dever”. As empresas hoje devem reencontrar valores há algumas décadas perdidos e que as levem a assumir o seu papel de cidadãs nas suas comunidades, com os seus direitos e deveres, como todos e cada um de nós. À comunicação pede-se-lhe que seja constitutiva desses mesmos processos e não meramente relatora de algumas dessas politicas ou acções.N/

A comunicação no desenvolvimento: Análise de tendências no uso da comunicação em projectos de desenvolvimento

O presente estudo foi realizado enquanto requisito parcial para a obtenção do grau de Mestre em Desenvolvimento, Diversidades Locais e Desafios Mundiais - análise e gestão. A temática evidenciada centra-se no papel potencial da disciplina da Comunicação no âmbito do Desenvolvimento, dentro de um contexto de desafios globais emergentes que exigem contínuos e renovados exercícios de reflexão e acção. Neste estudo expõem-se algumas das evidências empíricas recolhidas, fruto da implementação da comunicação em iniciativas de desenvolvimento ao longo das últimas décadas. O modelo de análise baseou-se num exercício de confronto entre permissas dos dois principais modelos teóricos de desenvolvimento - modernização e participação - e a sua relação com aspectos comunicativos, sendo que, a redução do exercício a apenas dois modelos foi intencional e realizada com vista à simplificação do exercício de comparação. O exercício comparativo permitiu analisar algumas das principais tendências e blind spots no uso da disciplina e a sua relação com os resultados obtidos, elementos que poderão ser considerados em futuras iniciativas de desenvolvimento de carácter comunicativo.This study was carried as a partial fulfilment of requirments for the degree of Master in Development, Local Diversities and Global Challenges - analysis and management. The thematic on focus relates to the potential role of Communication within Development, considering the world scenario of emerging global challenges, which demand continuous and renovated exercises of thought and action. In this study are exposed some of the empirical evidences collected, as a result of the use of communication within development initiatives in the last decades. The study analysis was based on the exercise of comparing the guidelines of the two main development models - modernization and participation - and their relation to communication aspects; reducing the exercise to only two models was intentionally made in order to simplify the comparison between cases. The comparative exercise has made possible to analyse some of the trends and blind spots of the use of communication within development, as well as their relation to the results obtained - elements which can be considered in future development initiatives

Modelling and simulation of biodiesel production processes

The reduction of CO2 and CH4 emissions to atmosphere is a matter of great concern nowadays since both gases can contribute signi cantly to the so-called greenhouse e ect that describes the trapping of heat near earth s surface by gases in the atmosphere. At the same time CO2=CH4 separations are of interest in treating gas streams like land ll gas, biogas and coal-bed methane. Accordingly, there is a need to investigate on this topic and that can be done with improved e cient technologies to separate or remove CO2 and CH4 from exhaust gases. Two recent reviews discuss this matter with great detail concerning the use of adsorbents (porous solids) based technologies to handle CO2 capture and CO2=CH4 separations [1, 2]. Biogas is mainly composed by CH4 (60 to 70%) and CO2 (30 to 40%) and to obtain a high energy content CO2 needs to be separated from CH4. For this purpose a variety of solid physical adsorbents have been considered including molecular sieve zeolites and a new class of adsorbents named Metal-Organic Frameworks (MOFs). The technology for biogas upgrading using adsorbents is called Pressure Swing Adsorption (PSA). With this technique, carbon dioxide is separated from the biogas by adsorption under elevated pressure. The adsorbing material, is regenerated by a sequential decrease in pressure before the column is reloaded again, hence the name of the technique. In this work, we will present sorption equilibrium, kinetic and xed bed data of CO2, CH4 in MOF-508b and zeolite 13X at 303, 323 and 343 K and partial pressures up to 4.5 bar. These data are tted with appropriate isotherm models. At the same time single, binary and ternary breakthrough curves were measured to provide required data to develop and validate a mathematical model based on the LDF approximation for the mass transfer, which could be used in the implementation (simulation) of a cyclic adsorption processes (PSA) for the puri cation of biogas and CO2 sequestration

A Lesson Study with Mathematics Teachers: Learning About Communication in the Classroom

Background: Orchestrating classroom communication is one of the challenges for teachers in exploratory lessons. Objectives: We aim to understand how the participation of secondary school teachers in a lesson study based on an exploratory approach promotes the development of their knowledge about classroom communication. Design: The research is qualitative and interpretative. Setting and Participants: The participants are three secondary school teachers who were willing to participate. Data collection and analysis: Data were collected through participant observation (with research journal and audio/video recording), document collection, and a focus group interview. Results: During the students’ autonomous work, although with different actions, closed progress details and open progress initiatives, the teachers listened to small-group discussions and used them as a starting point to support the students, asking them to explain their answers without pointing out the strategy to follow, according to what they discussed in the planning sessions. During the whole-class discussion, the teachers promoted the comparison of different representations and invited the students to explain and justify their answers, as they had planned, but also considered answers that they did not anticipate. After observing the research lesson, the teachers reflected about the students’ explanations, valuing their clarity, and referring to them as an opportunity for the teacher to understand how the students were thinking. Conclusions: The results suggest that lesson study is a professional development process in which secondary school teachers have the opportunity to deepen their knowledge about classroom communication

Leading whole-class discussions: From participating in a lesson study to teaching practice

Purpose – This article aims to analyse how a teacher leads whole-class discussions during and after participating in lesson studies and to what extent that participation influences her teaching practice. Design/methodology/approach – This is a qualitative/interpretative research with a case study design, carried out with a secondary school mathematics teacher who participated in two lesson studies. Data were collected from participant observation, audio recording of lesson study (LS) sessions and discussions with the teacher, video recording of lessons and semi-structured interviews. Frameworks regarding the teachers’ actions are used in the analysis. Findings – The results suggest that in her teaching practice, the teacher led students to explain their strategies with supporting/guiding actions, but she also challenged the students to justify their productions, ensuring that the students’ ideas were clear. Additionally, the teacher explored incorrect strategies and disagreements, inviting and challenging other students to intervene or react and involved students in drawing connections, as discussed in the LS. Therefore, the teacher put into practice several actions teachers can do in leading whole-class discussions to promote students’ learning. Participating in LS was an opportunity to rethink her teaching practice, as the teacher pointed out, bringing her a new perspective on leading discussions in which students play an active role in learning mathematics, creating opportunities for the students to explain and react to their colleagues’ ideas. Originality/value – This article examines an under-researched issue: the influence of LS on the way a teacher leads whole-class discussions, during and after participating in lesson studies.info:eu-repo/semantics/publishedVersio

A lesson study with mathematics teachers: learning about communication in the classroom

Background: orchestrating classroom communication is one of the challenges for teachers in exploratory lessons. Objectives: we aim to understand how the participation of secondary school teachers in a lesson study based on an exploratory approach promotes the development of their knowledge about classroom communication. Design: the research is qualitative and interpretative. Setting and participants: the participants are three secondary school teachers who were willing to participate. Data collection and analysis: data were collected through participant observation (with research journal and audio/videorecording), document collection, and a focus group interview. Results: during the students’ autonomous work, although with different actions, closed progress details and open progress initiatives, the teachers listened to small-group discussions and used them as a starting point to support the students, asking them to explain their answers without pointing out the strategy to follow, according to what they discussed in the planning sessions. During the wholeclass discussion, the teachers promoted the comparison of different representations and invited the students to explain and justify their answers, as they had planned, but also considered answers that they did not anticipate. After observing the research lesson, the teachers reflected about the students’ explanations, valuing their clarity, and referring to them as an opportunity for the teacher to understand how the students were thinking. Conclusions: the results suggest that lesson study is a professional development process in which secondary school teachers can deepen their knowledge about classroom communication