Neoliberalismo, política educacional e politecnia: tensões, contradições e possibilidades decorrentes do Decreto n. 5154/04

Este trabalho tem como problema central verificar se a integração do ensino médio facultada pelo Decreto n. 5.154/04 poderá constituir-se, ainda que sob os limites do capitalismo, num caminho que contribua para a concretização de uma concepção educacional voltada para a politecnia, tomando como referência a legislação educacional brasileira, no que diz respeito ao ensino médio e à educação profissional técnica de nível médio a partir da promulgação da LDB n. 9.394/96 e, tendo como foco principal de análise as disposições do Decreto n. 5.154/04 e as circunstâncias que eventualmente contribuem para que ele se constitua no caminho referido. Seu objetivo é analisar a precariedade, as limitações de alcance, mas também, as possibilidades do decreto como caminho alternativo na construção de outra concepção educacional, na perspectiva de superação do modelo vigente de inspiração neoliberal. O pressuposto ponto de partida é de que uma fundamentação teórico-metodológica, epistemológica e ético-política calcada na formação omnilateral e/ou politécnica que alcance significativamente os fóruns docentes, no âmbito do ensino médio e da educação profissional técnica de nível médio, dá suporte para que o Decreto n. 5.154/04 constitua-se de fato, numa possibilidade de travessia rumo à superação da concepção educacional de matiz neoliberal. No entendimento de que isso, todavia, não é algo que possa ocorrer espontaneamente, pelo contrário. Entendendo que a possibilidade dessa travessia implica uma intencionalidade e a disputa de um projeto que é também social. Uma preocupação se revela recorrente ao longo do trabalho: o que fazer? Face à opacidade do tempo presente pródigo em reduzir o oxigênio das nossas esperanças, em exaurir a possibilidade de se conceber uma sociabilidade que, diferente desta, tenha o homem como centro, agir de que maneira? E, principalmente, como propor uma ação que não pareça histriônica, descolada das atuais condições de tempo e espaço? Ao otimismo da vontade, ainda que face ao pessimismo da razão do pensamento gramsciano somamos utopia e poesia na expectativa de tornarmos a dimensão da transcendência mais tangível. Para lembramos que o homem pode ser maior do que o acabrunhado papel para ele determinado pelo sistema dominante. Com a intenção de dialogarmos com as experiências que se dão no chão das escolas, realizamos uma pesquisa intencional no campo empírico e através de dados colhidos junto a dirigentes e professores de três instituições da rede federal de educação tecnológica, de três unidades da federação, procuramos confrontar as informações obtidas com os principais argumentos apresentados no trabalho.

Advanced Reaction Systems for Hydrogen Production

[EN] This PhD work started in March 2010 with the support of the University of the Basque Country (UPV/EHU) under the program named “Formación de Personal Investigador” at the Chemical and Environmental Engineering Department in the Faculty of Engineering of Bilbao. The major part of the Thesis work was carried out in the mentioned department, as a member of the Sustainable Process Engineering (SuPrEn) research group. In addition, this PhD Thesis includes the research work developed during a period of 6 months at the Institut für Mikrotechnik Mainz GmbH, IMM, in Germany. During the four years of the Thesis, conventional and microreactor systems were tested for several feedstocks renewable and non-renewable, gases and liquids through several reforming processes in order to produce hydrogen. For this purpose, new catalytic formulations which showed high activity, selectivity and stability were design. As a consequence, the PhD work performed allowed the publication of seven scientific articles in peer-reviewed journals. This PhD Thesis is divided into the following six chapters described below. The opportunity of this work is established on the basis of the transition period needed for moving from a petroleum based energy system to a renewable based new one. Consequently, the present global energy scenario was detailed in Chapter 1, and the role of hydrogen as a real alternative in the future energy system was justified based on several outlooks. Therefore, renewable and non-renewable hydrogen production routes were presented, explaining the corresponding benefits and drawbacks. Then, the raw materials used in this Thesis work were described and the most important issues regarding the processes and the characteristics of the catalytic formulations were explained. The introduction chapter finishes by introducing the concepts of decentralized production and process intensification with the use of microreactors. In addition, a small description of these innovative reaction systems and the benefits that entailed their use were also mentioned. In Chapter 2 the main objectives of this Thesis work are summarized. The development of advanced reaction systems for hydrogen rich mixtures production is the main objective. In addition, the use and comparison between two different reaction systems, (fixed bed reactor (FBR) and microreactor), the processing of renewable raw materials, the development of new, active, selective and stable catalytic formulations, and the optimization of the operating conditions were also established as additional partial objectives. Methane and natural gas (NG) steam reforming experimental results obtained when operated with microreactor and FBR systems are presented in Chapter 3. For these experiments nickel-based (Ni/Al2O3 and Ni/MgO) and noble metal-based (Pd/Al2O3 and Pt/Al2O3) catalysts were prepared by wet impregnation and their catalytic activity was measured at several temperatures, from 973 to 1073 K, different S/C ratios, from 1.0 to 2.0, and atmospheric pressure. The Weight Hourly Space Velocity (WHSV) was maintained constant in order to compare the catalytic activity in both reaction systems. The results obtained showed a better performance of the catalysts operating in microreactors. The Ni/MgO catalyst reached the highest hydrogen production yield at 1073 K and steam-to-carbon ratio (S/C) of 1.5 under Steam methane Reforming (SMR) conditions. In addition, this catalyst also showed good activity and stability under NG reforming at S/C=1.0 and 2.0. The Ni/Al2O3 catalyst also showed high activity and good stability and it was the catalyst reaching the highest methane conversion (72.9 %) and H2out/CH4in ratio (2.4) under SMR conditions at 1073 K and S/C=1.0. However, this catalyst suffered from deactivation when it was tested under NG reforming conditions. Regarding the activity measurements carried out with the noble metal-based catalysts in the microreactor systems, they suffered a very quick deactivation, probably because of the effects attributed to carbon deposition, which was detected by Scanning Electron Microscope (SEM). When the FBR was used no catalytic activity was measured with the catalysts under investigation, probably because they were operated at the same WHSV than the microreactors and these WHSVs were too high for FBR system. In Chapter 4 biogas reforming processes were studied. This chapter starts with an introduction explaining the properties of the biogas and the main production routes. Then, the experimental procedure carried out is detailed giving concrete information about the experimental set-up, defining the parameters measured, specifying the characteristics of the reactors used and describing the characterization techniques utilized. Each following section describes the results obtained from activity testing with the different catalysts prepared, which is subsequently summarized: Section 4.3: Biogas reforming processes using γ-Al2O3 based catalysts The activity results obtained by several Ni-based catalysts and a bimetallic Rh-Ni catalyst supported on magnesia or alumina modified with oxides like CeO2 and ZrO2 are presented in this section. In addition, an alumina-based commercial catalyst was tested in order to compare the activity results measured. Four different biogas reforming processes were studied using a FBR: dry reforming (DR), biogas steam reforming (BSR), biogas oxidative reforming (BOR) and tri-reforming (TR). For the BSR process different steam to carbon ratios (S/C) from 1.0 to 3.0, were tested. In the case of BOR process the oxygen-to-methane (O2/CH4) ratio was varied from 0.125 to 0.50. Finally, for TR processes different S/C ratios from 1.0 to 3.0, and O2/CH4 ratios of 0.25 and 0.50 were studied. Then, the catalysts which achieved high activity and stability were impregnated in a microreactor to explore the viability of process intensification. The operation with microreactors was carried out under the best experimental conditions measured in the FBR. In addition, the physicochemical characterization of the fresh and spent catalysts was carried out by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), N2 physisorption, H2 chemisorption, Temperature Programmed Reduction (TPR), SEM, X-ray Photoelectron Spectroscopy (XPS) and X-ray powder Diffraction (XRD). Operating with the FBR, conversions close to the ones predicted by thermodynamic calculations were obtained by most of the catalysts tested. The Rh-Ni/Ce-Al2O3 catalyst obtained the highest hydrogen production yield in DR. In BSR process, the Ni/Ce-Al2O3 catalyst achieved the best activity results operating at S/C=1.0. In the case of BOR process, the Ni/Ce-Zr-Al2O3 catalyst showed the highest reactants conversion values operating at O2/CH4=0.25. Finally, in the TR process the Rh-Ni/Ce-Al2O3 catalyst obtained the best results operating at S/C=1.0 and O2/CH4=0.25. Therefore, these three catalysts were selected to be coated onto microchannels in order to test its performance under BOR and TR processes conditions. Although the operation using microreactors was carried out under considerably higher WHSV, similar conversions and yields as the ones measured in FBR were measured. Furthermore, attending to other measurements like Turnover Frequency (TOF) and Hydrogen Productivity (PROD), the values calculated for the catalysts tested in microreactors were one order of magnitude higher. Thus, due to the low dispersion degree measured by H2-chemisorption, the Ni/Ce-Al2O3 catalyst reached the highest TOF and PROD values. Section 4.4: Biogas reforming processes using Zeolites L based catalysts In this section three type of L zeolites, with different morphology and size, were synthesized and used as catalyst support. Then, for each type of L zeolite three nickel monometallic and their homologous Rh-Ni bimetallic catalysts were prepared by the wetness impregnation method. These catalysts were tested using the FBR under DR process and different conditions of BSR (S/C ratio of 1.0 and 2.0), BOR (O2/CH4 ratio of 0.25 and 0.50) and TR processes (at S/C=1.0 and O2/CH4=0.25). The characterization of these catalysts was also carried out by using the same techniques mentioned in the previous section. Very high methane and carbon dioxide conversion values were measured for almost all the catalysts under investigation. The experimental results evidenced the better catalytic behavior of the bimetallic catalysts as compared to the monometallic ones. Comparing the catalysts behavior with regards to their morphology, for the BSR process the Disc catalysts were the most active ones at the lowest S/C ratio tested. On the contrary, the Cylindrical (30–60 nm) catalysts were more active under BOR conditions at O2/CH4=0.25 and TR processes. By the contrary, the Cylindrical (1–3 µm) catalysts showed the worst activity results for both processes. Section 4.5: Biogas reforming processes using Na+ and Cs+ doped Zeolites LTL based catalysts A method for the synthesis of Linde Type L (LTL) zeolite under microwave-assisted hydrothermal conditions and its behavior as a support for heterogeneously catalyzed hydrogen production is described in this section. Then, rhodium and nickel-based bimetallic catalysts were prepared in order to be tested by DR process and BOR process at O2/CH4=0.25. Moreover, the characterization of the catalysts under investigation was also carried out. Higher activities were achieved by the catalysts prepared from the non-doped zeolites, Rh-Ni/D and Rh-Ni/N, as compared to the ones supported on Na+ and Cs+ exchanged supports. However, the differences between them were not very significant. In addition, the Na+ and Cs+ incorporation affected mainly to the Disc catalysts. Comparing the results obtained by these catalysts with the ones studied in the section 4.4, in general worst results were achieved under DR conditions and almost the same results when operated under BOR conditions. In Chapter 5 the ethylene glycol (EG) as feed for syngas production by steam reforming (SR) and oxidative steam reforming (OSR) was studied by using microchannel reactors. The product composition was determined at a S/C of 4.0, reaction temperatures between 625°C and 725°C, atmospheric pressure and Volume Hourly Space Velocities (VHSV) between 100 and 300 NL/(gcath). This work was divided in two sections. The first one corresponds to the introduction of the main and most promising EG production routes. Then, the new experimental procedure is detailed and the information about the experimental set-up and the measured parameters is described. The characterization was carried out using the same techniques as for the previous chapter. Then, the next sections correspond to the catalytic activity and catalysts characterization results. Section 5.3: xRh-cm and xRh-np catalysts for ethylene glycol reforming Initially, catalysts with different rhodium loading, from 1.0 to 5.0 wt. %, and supported on α-Al2O3 were prepared by two different preparation methods (conventional impregnation and separate nanoparticle synthesis). Then, the catalysts were compared regarding their measured activity and selectivity, as well as the characterization results obtained before and after the activity tests carried out. The samples prepared by a conventional impregnation method showed generally higher activity compared to catalysts prepared from Rh nanoparticles. By-product formation of species such as acetaldehyde, ethane and ethylene was detected, regardless if oxygen was added to the feed or not. Among the catalysts tested, the 2.5Rh-cm catalyst was considered the best one. Section 5.4: 2.5Rh-cm catalyst support modification with CeO2 and La2O3 In this part of the Chapter 5, the catalyst showing the best performance in the previous section, the 2.5Rh-Al2O3 catalyst, was selected in order to be improved. Therefore, new Rh based catalysts were designed using α-Al2O3 and being modified this support with different contents of CeO2 or La2O3 oxides. All the catalysts containing additives showed complete conversion and selectivities close to the equilibrium in both SR and OSR processes. In addition, for these catalysts the concentrations measured for the C2H4, CH4, CH3CHO and C2H6 by-products were very low. Finally, the 2.5Rh-20Ce catalyst was selected according to its catalytic activity and characterization results in order to run a stability test, which lasted more than 115 hours under stable operation. The last chapter, Chapter 6, summarizes the main conclusions achieved throughout this Thesis work. Although very high reactant conversions and rich hydrogen mixtures were obtained using a fixed bed reaction system, the use of microreactors improves the key issues, heat and mass transfer limitations, through which the reforming reactions are intensified. Therefore, they seem to be a very interesting and promising alternative for process intensification and decentralized production for remote application.

Modeling habits as self-sustaining patterns of sensorimotor behavior

In the recent history of psychology and cognitive neuroscience, the notion of habit has been reduced to a stimulus-triggered response probability correlation. In this paper we use a computational model to present an alternative theoretical view (with some philosophical implications), where habits are seen as self-maintaining patterns of behavior that share properties in common with self-maintaining biological processes, and that inhabit a complex ecological context, including the presence and influence of other habits. Far from mechanical automatisms, this organismic and self-organizing concept of habit can overcome the dominating atomistic and statistical conceptions, and the high temporal resolution effects of situatedness, embodiment and sensorimotor loops emerge as playing a more central, subtle and complex role in the organization of behavior. The model is based on a novel "iterant deformable sensorimotor medium (IDSM)," designed such that trajectories taken through sensorimotor-space increase the likelihood that in the future, similar trajectories will be taken. We couple the IDSM to sensors and motors of a simulated robot, and show that under certain conditions, the IDSM conditions, the IDSM forms self-maintaining patterns of activity that operate across the IDSM, the robot's body, and the environment. We present various environments and the resulting habits that form in them. The model acts as an abstraction of habits at a much needed sensorimotor "meso-scale" between microscopic neuron-based models and macroscopic descriptions of behavior. Finally, we discuss how this model and extensions of it can help us understand aspects of behavioral self-organization, historicity and autonomy that remain out of the scope of contemporary representationalist frameworks.

Uso de ambientes virtuais para a simulação de acidentes radiológicos

Em um ambiente virtual, construído com o uso de tecnologia computacional, encontram-se presentes entidades virtuais inseridas em um espaço tridimensional, que é utilizado para a simulação de processos críticos, como os acidentes radiológicos. A pronta detecção de um acidente radiológico e a determinação da sua possível extensão são fatores essenciais para o planejamento de respostas imediatas e de ações de emergência. A integração das representações georeferenciadas do espaço tridimensional, com modelos baseados em agentes autônomos, com o objetivo de construir ambientes virtuais que tenham a capacidade de simular acidentes radiológicos é a proposta dessa tese. As representações georeferenciadas do espaço tridimensional candidatas são: i)as representações espaciais usadas nos sistemas de informações geográficas (SIG) e ii) a representação adotada pelo Google MapsTM. Com o uso deste ambiente pode-se: quantificar as doses recebidas pelas pessoas; ter uma distribuição espacial das pessoas contaminadas; estimar o número de indivíduos contaminados; estimar o impacto na rede de saúde; estimar impactos ambientais; gerar zonas de exclusão; construir cenários alternativos; treinar pessoal técnico para lidar com acidentes radiológicos.

O livro didático de alfabetização na era do letramento: uma análise crítica

Essa pesquisa insere-se em um contexto de muitas discussões acerca da qualidade da educação no Brasil, motivadas principalmente pelos maus resultados atingidos pelo país em exames internacionais. Os constantes debates têm dado margem, inclusive, a movimentos que, culpando os PCNs pelo fracasso generalizado na alfabetização, clamam pela volta de um ensino tradicional. De fato, apesar das imensas contribuições trazidas pelos estudos que embasam os PCNs, apenas a sua institucionalização não garantiu a ocorrência de mudanças efetivas na educação. Principalmente no campo da alfabetização, interpretações equivocadas levaram, por exemplo, ao desencadeamento de um processo de desmetodização do ensino, caracterizado pela exclusão total, nos últimos anos, das questões de ordem metodológica das pautas de discussões. Tal fenômeno, denominado por Soares (2004) de desinvenção da alfabetização, e também abordado por outros pesquisadores (cf. MORAIS, 2006; FRADE, 2003; CARVALHO, 2007), obviamente, acabou se refletindo nos novos livros didáticos, avaliados e recomendados pelo MEC. O problema é que os novos livros parecem não estar satisfazendo às necessidades dos docentes. Estudos recentes têm revelado tanto uma insatisfação desses profissionais em relação a tais materiais quanto a manutenção de práticas didáticas preconizadas pelos métodos tradicionais (Cf. BRITO et al., 2007; SILVA 2008; e MORAIS E ALBURQUERQUE, 2008). Considerando-se que: (a) hoje já se reconhece que os processos de alfabetização e letramento são complementares e indissociáveis (SOARES, 2004); (b) na realidade brasileira os livros didáticos ainda são recursos centrais no trabalho em sala de aula; (c) as obras são avaliadas a partir de rígidos critérios, alinhados às mais recentes teorias; e (d), a disponibilização gratuita desses materiais demanda um alto investimento do governo, o objetivo deste estudo foi analisar criticamente um dos livros didáticos de alfabetização do PNLD/2010 (L.E.R., Leitura, escrita e reflexão 1 ano, FTD), na tentativa de levantar pistas sobre os possíveis motivos dessa não-adesão dos docentes aos novos livros. Para tanto, foi realizada uma análise documental crítica, de abordagem qualitativa, que observou na obra os seguintes aspectos: o espaço dedicado ao ensino do sistema de escrita alfabética; a existência de articulação desse trabalho com o de letramento; a coerência entre a orientação pedagógica declarada e as atividades propostas; e a clareza e objetividade das instruções e sugestões fornecidas ao docente. As análises realizadas mostram, entre os dados mais relevantes, que o livro estudado ainda dedica um espaço muito reduzido às atividades de ensino do sistema de escrita e não apresenta uma articulação satisfatória entre essas atividades e àquelas voltadas ao letramento, corroborando dados de outros estudos, aqui já mencionados. Esses resultados podem ser indicativos de que os critérios estipulados para a avaliação desses livros precisariam ser revistos de forma que atendessem mais equilibradamente tanto aos objetivos da alfabetização e do letramento quanto às necessidades da prática docente. Para um maior aprofundamento deste estudo considero que, futuramente, seus dados podem ser complementados por análises dos próprios docentes sobre o livro estudado, ou até mesmo por pesquisas sobre seu uso efetivo em sala de aula

Double-cladding Yb3+ fiber for free-space optical communication

The experiment result of Nd:YVO4 laser pumped by laser diode that was amplified by double-cladding Yb3+ fiber is reported. Stable mode-locking pulses are obtained at repetition rate of 320 MHz and the output power is 15 mW. When laser power is amplified by Yb3+- doped double-cladding fiber amplifier, its power can get to 600 mW. Based on these, experiment of double-frequency is carried out, and green laser with power of 4 mW is obtained. (c) 2007 Wiley Periodicals, Inc.