Simulação Da Captura De CO2 Por Meio De Pós-Combustão De Carvão Mineral

TCC (graduação) - Universidade Federal De Santa Catarina - Campus Araranguá. Engenharia de EnergiaDevido à crescente emissão de gases do efeito estufa, tem-se buscado processos mais limpos, principalmente relacionados à emissão de CO2. Uma das soluções para esse grave problema é a captura e armazenagem de carbono. O objetivo deste estudo foi avaliar o impacto da implantação da tecnologia de captura de CO2 na pós-combustão utilizando o software IECM-CS. Foram feitas simulações tendo como objeto de estudo a UTLC do Complexo Termelétrico Jorge Lacerda, maior termelétrica do Brasil e da América Latina, tomada como planta base para comparação com uma planta virtual simulando a inserção da tecnologia de captura na pós-combustão. Por meio dos resultados decorrentes dessas simulações, foi possível avaliar o impacto da tecnologia na redução das emissões atmosféricas, investigar opções para aproveitamento de resíduos (dióxido de carbono, dióxido de enxofre e cinzas leves e pesadas). Também comparou-se o preço da energia elétrica produzida pela planta base com o preço simulado pelo IECM-CS com a implantação da tecnologia de captura de CO2 considerada, verificando-se um aumento de 136,32% no custo da energia elétrica. Além disso, a instalação do sistema de captura de CO2 reduziu a eficiência da planta em torno de 20%, com acréscimo de 58,53% no consumo de água

Avaliação formativa no espaço de aprendizagem digital da matemática: uma experiência no Facebook com ensino médio

O trabalho articula os conceitos de avaliação formativa e espaço de aprendizagem digital nas aulas de Matemática, aplicado a Escola Básica e Pública, com estudantes do Ensino Médio, em 2012. A metodologia é, primeiro, teórica sobre estes conceitos, e depois aplicada, um estudo de caso, a uma turma que escolhe a rede social Facebook como seu espaço. O objetivo é como construir a avaliação formativa da aprendizagem de Matemática no Facebook. E esta construção é essencial às aulas de Matemática na Escola Básica, porque é de notório saber, por exemplo, as dificuldades dos estudantes com os conceitos desta disciplina, então é necessário mudar a sala de aula, e para isso mobilizar os estudantes, por exemplo, incluindo recursos digitais que lhes são interessante sé um meio. Um resultado, sob o olhar dos estudantes, é que estes aprendem Matemática de verdade interagindo com os colegas; e sob o ponto de vista dos professores, observando as resoluções dos estudantes no Facebook é possível verificar suas estratégias e dificuldades, além de ser uma forma de avaliar que contempla todo o desenvolvimento do estudanteAbstract: The paper articulates the concepts of formative assessment and digital learning space in math class, applied to Public Schools and with high school students in 2012. The methodology is first on these theoretical concepts, and then applied a case study, a group who choose Facebook as their social network space. The goal is to build formative assessment of learning math on Facebook. And this construction is essential to mathematics classes in Primary School, because it is public knowledge, for example, students' difficulties with the concepts of this discipline, then it is necessary to change the classroom, and for that mobilize students, eg including digital resources that are interesting to them is a means. A result, under the gaze of the students is that they learn mathematics actually interacting with colleagues, and from the point of view of teachers, noting the resolutions of students on Facebook you can check their strategies and difficulties, as well as being a form to assess which includes all development of the student.Universidade Aberta; Pavilhão do Conhecimento; LEA

A safety stock adjustment procedure to enable target service levels in simulation of generic inventory systems

The aim of this paper is to present a technique, called the safety stock adjustment procedure (SSAP), which enables the determination of safety stocks that ensure target service levels in simulation studies of inventory systems. The technique is based on a netting procedure constructed so that the net requirement process and the replenishment process are independent of the safety stock and that the inventory process satisfies an invariance relation. The procedure is presented for three kinds of service measures; namely the cycle service level, the fill rate and the ready rate. In a numerical example the benefits of using the safety stock adjustment procedure are shown. In this example three wellknown lot size models are compared assuming stochastic and time-varying demand. Moreover, we propose the safety stock adjustment procedure to be used in practical situations to set safety stock levels in companies for instance when demand is nonstationary. Keywords

Canonical Quantum Supergravity in Three Dimensions, (some lines lost during submission)

We discuss the canonical treatment and quantization of matter coupled supergravity in three dimensions, with special emphasis on $N=2$ supergravity. We then analyze the quantum constraint algebra; certain operator ordering ambiguities are found to be absent due to local supersymmetry. We show that the supersymmetry constraints can be partially solved by a functional analog of the method of characteristics. We also consider extensions of Wilson loop integrals of the type previously found in ordinary gravity, but now with connections involving the bosonic and fermionic matter fields in addition to the gravitational connection. In a separate section of this paper, the canonical treatment and quantization of non-linear coset space sigma models are discussed in a self contained way.Comment: 40 pages, LaTeX, DESY 93-07

Experimental study of formwork tightness as a function of rheological properties of SCC

Several studies relating formwork pressure to rheology exist, however the relationship between rheology and leakage through formwork joints remains to be investigated. In practice, standard documents are used to define formwork tightness requirements, typically using a qualitative approach. To try bridge this gap in knowledge, we developed a test set-up to study tightness of formwork joints under pressure as a function of varying rheological properties. Coupled with standard rheology tests, this new test set-up provides means of linking flow rate, formwork pressure, flow area, and the rheological properties. The study seeks to provide insight on measurable governing parameters and thus inform formwork tightness requirements in a more quantifiable manner. This paper presents a test set-up designed to study the flow of fresh paste through small openings. It highlights a preliminary study on the pressure-driven flow of limestone paste through a bottom orifice in a cylindrical container. While this new device may not be directly representative of the actual conditions in formwork, it provides a good base for a fundamental study that can then be extrapolated to a more representative test operation. Preliminary results show a linear relationship between the flow rate and the applied pressure. The results also show that increasing the flow area by a factor of 2.33 had a higher impact than an increase in yield stress and viscosity by a factor of 2.54 and 3.80 respectively. However, more tests need to be carried out to obtain clear trends

Transmission electron microscopy and energy dispersive X-ray spectroscopy on the worn surface of nano-structured TiAlN/VN multilayer coating

Nano-structured TiAIN/VN multilayer hard coatings grown by cathodic arc metal ion etching and unbalanced magnetron sputtering deposition have repeatedly shown low coefficients of friction and wear. In this paper, we employed the combined methods of cross-sectional ion beam milling sample preparation, conventional transmission electron microscopy, energy dispersive X-ray spectroscopy and quantitative spectrum analysis to give a comprehensive characterization of wear induced tribofilm, worn TiAIN/VN surface as well as wear debris. The major wear mechanism operating in the TiAIN/VN coating is the tribo-oxidation wear. A 20-50 nm thick tribofilm was observed on the TiAIN/VN worn surface, having inhomogeneous density, amorphous structure and multicomponent V-Al-Ti-O composition. Therefore the real sliding contact during the ball-on-disk test was a three-body sliding system including the tribofilm, in which the self-sintering and shearing deformation of the multicomponent oxide film played a significant role in determining the low friction coefficient. Owing to the low friction and high hardness, the TiAIN/VN worn surface retained good structural integrity without any crack, delamination or detectable deformation, resulting in minimized mechanical wear. (c) 2005 Elsevier B.V. All rights reserved

Regeneração de plantas de Eucalyptus camaldulensis a partir das explantes cotiledonares

A implementação, para espécies florestais, de técnicas de melhoramento baseadas em métodos de transformação genética, permitirá reduzir os longos ciclos de melhoramento e evitar a manipulação de árvores adultas. Isto implica dispor de um protocolo de regeneração que permita o desenvolvimento de plantas a partir de tecidos transformados. Este trabalho teve como objetivo otimizar este protocolo de regeneração para Eucalyptus camaldulensis. Folhas cotiledonares foram cultivadas em meio de cultura MS suplementado com combinações de ácido naftalenoacético (ANA) e 6-benzilaminopurina (BAP). O tratamento mais eficiente em termos de regeneração indireta de gemas foi 2,7 µmol L-1 de ANA combinado com 4,44 µmol L-1 de BAP, o qual foi utilizado nos experimentos posteriores. A manutenção dos explantes no escuro durante os trinta primeiros dias elevou a porcentagem de explantes com calos e reduziu a morte dos explantes, em comparação com os que permaneceram na luz. Modificações da composição mineral do meio MS foram comparadas e mostraram que a redução de metade dos sais foi tão eficiente para a formação de gemas (54% dos explantes) quanto o meio completo (47%). O meio de cultura com a concentração de íons nitrato e amônio reduzida à metade e 0,2% de carvão ativado apresentou-se adequado para o alongamento e enraizamento das brotações que atingiram uma altura de 1 a 8 cm depois de 30 dias. O processo completo representa um protocolo eficiente para a regeneração de plantas de Eucalyptus camaldulensis, uma vez que reduz o número de etapas para a obtenção de plantas completas.Breeding methods based on genetic transformation techniques need to be implemented for Eucalyptus camaldulensis to shorten the long breeding cycles and avoid manipulation of adult trees; that requires the development of plant regeneration protocols enabling development of plants from transformed tissues. The present work aimed to optimise the regeneration process already established for the species. Cotyledonary leaves of E. camaldulensis were cultured in MS medium supplemented with naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) combinations. The most efficient treatment for bud indirect regeneration (2.7 µmol L-1 NAA and 4.44 µmol L-1 BAP) was used for further experiments. When explants were kept in the dark during the first 30 days, the percentage of explants forming calluses increased and explant necrosis was reduced in comparison with light-cultured explants. Mineral medium modifications were compared and half-strength MS mineral medium turned out to be as efficient as full-strength medium, producing 54% and 47% of explants with buds, respectively. For shoot elongation, MS medium with half-strength nitrate and ammonium salts, and 0.2% activated charcoal yielded rooted shoots 1 to 8 cm high after one month. The procedure is an efficient protocol for E. camadulensis plant regeneration, reducing the stages necessary for the obtention of complete plants

Taking into account water use impacts in the LCA of biofuels: an Argentinean case study

Purpose: The assessment of biofuels has until now mainly focused on energy demand and greenhouse gas emissions. Only little attention has been given to other impacts, although the general importance of water use for the life cycle assessment (LCA) of agricultural products has been recognized in recent publications. The aim of this work is to assess in detail the water consumption along a biofuel production chain taking into account irrigation efficiencies, levels of water scarcity, and type of feedstock, and to integrate those results in a full LCA. Furthermore, we compare the results for biofuels from various feedstocks and regions with conventional petrol. Methods: We calculate the water consumption and overall life cycle assessment results in a case study for the production of methyl ester from irrigated and non-irrigated rapeseed. The results are compared with other irrigated and non-irrigated biofuels based on different feedstocks. Results and discussion: Water consumption in biofuel production chains based on non-irrigated crops does not vary greatly and is in the same range as for fossil fuel. In contrast, as a consequence of irrigation, agricultural water consumption dominates the overall results of all irrigated crops. Consequently, the level of water scarcity plays a key role for the LCA results. In our case study, the environmental impacts of methyl ester from irrigated rapeseed in a water-scarce region, measured in aggregated Eco-Indicator 99 scores, are almost doubled by water consumption. Variations in irrigation efficiency, however, are of little influence on the results, as the assessment method used here is based on consumptive water, which depends mainly on the evapotranspiration of the crop. Conclusions: The focus on greenhouse gas emissions of the main regulatory schemes neglects other relevant environmental impacts and may provide the wrong incentives. Water consumption may thus become a major concern, offsetting the benefits of biofuel use with respect to climate chang

Forestry restoration in abandoned pastures of Urochloa by different sizes of brushwood.

A galharia é um método de complexação ambiental, que consiste no aproveitamento de resíduos vegetais. Esse método, quando bem estabelecido tecnicamente, pode exercer influência sobre a qualidade da cama de sementes, favorecendo o estabelecimento de plantas nativas e a restauração do ecossistema. Dessa forma, objetivou-se avaliar a eficiência de galharia para a indução da regeneração natural de espécies nativas em área coberta por gramíneas exóticas inibidoras do gênero Urochloa, bem como verificar o tamanho mínimo necessário para conter a reinvasão das forrageiras. Como hipótese, adotou-se a largura mínima de 4 m como suficiente para o estabelecimento da regeneração natural, antes da reocupação das forrageiras. O experimento foi conduzido entre maio 2014 e maio 2016 em Morretes-PR, na Floresta Ombrófila Densa de Terras Baixas. Foram implantados sete tamanhos de galharia: 6 x 1, 6 x 2, 6 x 3, 6 x 4, 6 x 5, 6 x 6 m e testemunha. As espécies lenhosas foram identificadas e contadas e a porcentagem de cobertura herbácea estimada após 4, 8, 12, 18 e 24 meses. Não se verificou retomada da sucessão natural por espécies nativas. Independentemente do tamanho, a galharia foi ineficiente para conter a reinvasão pelas gramíneas a partir das bordas das parcelas e, como pilha de resíduos, dificultou o estabelecimento de espécies lenhosas. Para a criação de safe sites e consequente restauração via regeneração natural, faz-se necessária a eliminação local das forrageiras Urochloa, sem a qual espécies nativas terão pouca probabilidade de sobreviver