895 resultados para Hot Forming Process
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Passion fruit is widely consumed due to its pleasant flavour and aroma acidity, and it is considered very important a source of minerals and vitamins. It is used in many products such as ice-cream, mousses and, especially, juices. However, the processing of passion fruit juice may modify the composition and biodisponibility of the bioactive compounds. Investigations of the effects of processing on nutritional components in tropical juices are scarce. Frequently, only losses of vitamin C are evaluated. The objective of this paper is to investigate how some operations of passion fruit juice processing (formulation/homogeneization/thermal treatment) affect this product's chemical and physicochemical characteristics. The results showed that the chemical and physicochemical characteristics are little affected by the processing although a reduction in vitamin C contents and anthocyanin, large quantities of carotenoids was verified even after the pasteurization stage.
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KESLA 2110T -autonosturin siirtopuomin teleskooppimainen rakenne koostuu kolmesta sisäkkäin menevästä puomista. Näiden puomien muodonmuutokset ja mittavaihtelut ovat kriittisiä seikkoja siirtopuomin kokoonpantavuuden kannalta. Liian suuret muodonmuutokset ja mittavaihtelut aiheuttavat ylimääräistä työtä siirtopuomien kokoonpanossa, mikä lisää tuotteen läpimenoaikaa ja valmistuskustannuksia. Työssä pyrittiin selvittämään valmistusprosessin kriittisimmät osat kokoonpantavuuden kannalta sekä varmistamaan niiden vaikutus mittauksin. Valmistusprosessin ongelmakohtia selvitettiin ensin haastattelemalla tuotannon työntekijöitä ja toimihenkilöitä. Saatujen tuloksien perusteella suunniteltiin tarkoituksenmukaiset mittausjärjestelyt, joilla valmistusprosessin ongelmakohdat voidaan todeta. Mittaukset suoritettiin kahdelle viiden siirtopuomin koesarjalle ja samalla kehitettiin valmistusprosessia. Puomien mittauksissa keskityttiin kokoonpanon kannalta kriittisiin mittoihin. Mittatuloksia arvioidaan toleranssien, standardien ja prosessien suorituskyvyn parametrien avulla. Työssä selvitettiin myös rullamuovauksen soveltuvuutta puomien valmistusmenetelmäksi sekä välyksen vaikutusta kokoonpantavuuden kehittämiseksi. Mittauksissa havaittiin mittavirheiden kertautuvan valmistusprosessin varrella. Kokoonpantavuuden kannalta kriittisimmät virheet ovat puomien alakotelon V-pohjan toislaitaisuus sekä puomien kieroutuminen hitsausvaiheessa. Puomien korkeus- tai leveysvaihteluilla ei ole suurta merkitystä, sillä niitä voidaan kompensoida liukupaloja säätämällä.
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Three-dimensional (3D) forming of paperboard and heat sealing of lidding films to trays manufactured by the press forming process are investigated in this thesis. The aim of the work was to investigate and recognize the factors affecting the quality of heat sealing and the leak resistance (tightness) of press-formed, polymer-coated paperboard trays heatsealed with a multi-layer polymer based lidding film. One target was to achieve a solution that can be used in food packaging using modified atmosphere packaging (MAP). The main challenge in acquiring adequate tightness properties for the use of MAP is creases in the sealing area of the paperboard trays which can act as capillary tubes and prevent leak-proof sealing. Several experiments were made to investigate the effect of different factors and process parameters in the forming and sealing processes. Also different methods of analysis, such as microscopic analysis and 3D-profilometry were used to investigate the structure of the creases in the sealing area, and to analyse the surface characteristics of the tray flange of the formed trays to define quality that can be sealed with satisfactory tightness for the use of MAP. The main factors and parameters that had an effect on the result of leak-proof sealing and must be adjusted accordingly were the tray geometry and dimensions, blank holding force in press forming, surface roughness of the sealing area, the geometry and depth of the creases, and the sealing pressure. The results show that the quality of press-formed, polymer-coated paperboard trays and multi-layer polymer lidding films can be satisfactory for the use of modified atmosphere packaging in food solutions. Suitable tools, materials, and process parameters have to be selected and used during the tray manufacturing process and lid sealing process, however. Utilizing these solutions and results makes it possible for a package that is made mostly from renewable and recyclable sources to be a considerable alternative for packages made completely from oil based polymers, and to achieve a greater market share for fibre-based solutions in food packaging using MAP.
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This doctoral thesis addresses the growing concern about the significant changes in the climatic and weather patterns due to the aerosol loading that have taken place in the Indo Gangetic Plain(IGP)which includes most of the Northern Indian region. The study region comprises of major industrial cities in India (New Delhi, Kanpur, Allahabad, Jamshedpur and Kolkata). Northern and central parts of India are one of the most thickly populated areas in the world and have the most intensely farmed areas. Rapid increase in population and urbanization has resulted in an abrupt increase in aerosol concentrations in recent years. The IGP has a major source of coal; therefore most of the industries including numerous thermal power plants that run on coal are located around this region. They inject copious amount of aerosols into the atmosphere. Moreover, the transport of dust aerosols from arid locations is prevalent during the dry months which increase the aerosol loading in theatmosphere. The topography of the place is also ideal for the congregation of aerosols. It is bounded by the Himalayas in the north, Thar Desert in the west, the Vindhyan range in the south and Brahmaputra ridge in the east. During the non‐monsoon months (October to May) the weather in the location is dry with very little rainfall. Surface winds are weak during most of the time in this dry season. The aerosols that reach the location by means of long distance transport and from regional sources get accumulated under these favourable conditions. The increase in aerosol concentration due to the complex combination of aerosol transport and anthropogenic factors mixed with the contribution from the natural sources alters the optical properties and the life time of clouds in the region. The associated perturbations in radiative balance have a significant impact on the meteorological parameters and this in turn determines the precipitation forming process. Therefore, any change in weather which disturbs the normal hydrological pattern is alarming in the socio‐economic point of view. Hence, the main focus of this work is to determine the variation in transport and distribution of aerosols in the region and to understand the interaction of these aerosols with meteorological parameters and cloud properties.
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Este trabalho pretende, na visão de novas tecnologias, discutir o processo de forjamento das ligas de alumínio (ABNT 6061), buscando propor uma metodologia baseada na ciência da engenharia. Deseja-se minimizar os procedimentos de tentativa e erro no desenvolvimento de processos de conformação. Para tanto, novas tecnologias disponíveis atualmente, tais como o Projeto Assistido por Computador (CAD), a Fabricação Assistida por Computador (CAM) e a Simulação do Processo (CAE) são empregadas. Resultados experimentais mostrando o comportamento da liga ABNT 6061 através das curvas de escoamento bem como o estabelecimento da condição do atrito no processo de conformação, avaliando dois lubrificantes comerciais disponíveis (Deltaforge 31 e Oildag) para aplicações nas ligas de alumínio, são reportados neste trabalho. A comparação dos resultados obtidos de um experimento prático de forjamento com a simulação pelo “Método dos Elementos Finitos” usando o código “QForm” é apresentada para uma peça de simetria axial em liga de alumínio. Finalmente, os resultados obtidos no forjamento de um componente automotivo em liga de alumínio (ABNT 6061), desenvolvido em parceria com a empresa Dana, são analisados e comparados com as simulações computacionais realizadas usando o código “Superforge”.
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Ao repensar-se a formação do educador, visando sua participação critica e consciente na sociedade, a Educação em Sa~de 6 objet6 de reflexão te6rico-metodo16gica. Assim, ã postura tradicional no ensino de sa~de - normativa, ing-ª. nua, restrita ã dimensão bio16gica, contrapõe-se atualmente a concepção de sa~dc como direito. O presente trabalho consiste em uma reflexão sobre a problemática Educação-Sa~de e Cidadania na sociedade brasileira, focalizando-se o papel da escola p~blica na co~ quista coletiva da sa~de. Reconhecendo-se a Educação como prática mediadora, que se articula dialeticamente a total i dade social, discute-se aqui as possibilidades e limites da Educação em Sa~de, no sentido de sua contribuição a melhoria da qualidade de vida e sa~de do povo brasileiro. sao analisadas, em uma perspectiva hist6rica, as tend~ncias pedag6gicas na area da Educação em Sa~de, identificando- se seus pressupostos filos6ficos e conte~do ideb l6gico; 6 tamb6~ investigada a função po1ftica exercida pc la Educação em Sa~de no contexto da formação so~ial capit~ lista. Considera-se importante que o compromisso polft! co dos educadores se concretize na compet6ncia profissio - nal, viabilizando a Escola P~blica constituir-se como esp~ ço de interpretação e transformação da realidade. Isso & algo a ser construido coletivamente, no cotidiano da escola, em condições dignas de trabalho; relaciona-se, portanto, ã uma polftica educacional de efetiva valorização da I ducação P~blica. Concluindo, enfatiza-se a importãncia da organizaçao e fortalecimento da sociedade civil para que o direi to constitucional a Sa~de e a Educação se torne uma realidade para todos os cidadãos brasileiros.
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Este trabalho procura elucidar alguns conceitos teóricos de identidade, como é entendida por diferentes autores, como nós a interpretamos e como o processo educacional influencia o desenvolvimento da identidade dos adolescentes. Para isso recorremos ao fenômeno da identificação, aos conflitos intra-psíquicos, particularmente no período da adolescência, e aos vínculos de integração espacial, temporal e social. Consideramos a identidade estruturada por três níveis fundamentais: pelas estruturas mais desenvolvidas da personalidade, caracterizada pela relação interpessoal, baseada nos mecanismos de projeção e introjeção; pelos mecanismos de identificação projetiva-introjetiva e pela persistência da fusão ou estrutura sincicial primitiva que caracteriza a sociabilidade sincrética. Partimos da concepção de identificação como a forma mais primitiva de ligação afetiva. Tomamos a conquista da identidade corporal e sexual como a base das demais identidades parciais. A formação da identidade como um todo, que pressupõe uma crise na adolescência, baseia-se na problemática mais específica da formação de uma identidade sexual. Enquanto a identificação se opera através de introjeções, a identidade resulta da oposição de identificações anteriores. O processo é dialético. Somos de opinião que a identidade é formada por processos eminentemente sociais. Uma vez formada, é mantida, modificada ou mesmo remodelada pelas relações sociais. Nossa preocupação centralizou-se no processo de formação de identidade, considerado em estreita relação çom a família, a escola e a sociedade e em contínua interaçao professor-aluno, ensino-aprendizagem. Tentamos detectar as influências da educação sistematizadas no processo de formação da identidade e em especial visualizar o papel do professor no referido processo, através de pesquisa de campo. Para isso elaboramos um questionário composto de duas partes. A primeira contendo dados de identificação do aluno, da família e da escola. A segunda, composta de 40 perguntas consideradas, inferencialmente, como indicadores dos vínculos de integração espacial, temporal e social. Os sujeitos de nossa pesquisa constituiram-se de 176 alunos, na faixa etária de 14 anos, masculinos e femininos, de 5ª e 8ª series, do ensino de 1º grau das escolas da rede estadual de Divinopolis, M.G., em 1978. A análise dos dados obtidos evidenciou o desenvolvimento de nossos sujeitos em termos de identificação com os grupos primários, predominando a dependência em nível infantil.
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This study focuses on the central Brazilian historiography of science, focusing specifically on the life and work of a contemporaneous mathematician-physicist, and becomes part of the set of research results that investigate, organize and describe personal, intellectual and professional itineraries of Brazilian scientists and educators. The theme chosen for the study ran from seminars on Mathematics in Pará and is up to organize and describe the life history, education, professional experience and scientific production of William Mauricio Souza Marcos de La Penha (Guilherme de La Penha), considering their academic, professional and intellectual life history, so that their academic and intellectual production be spread over the Brazilian scientific and academic community. We adopted the historical research as theoretical and methodological base for the development of this study, rising arguments about the profile of Guilherme de La Penha to characterize him as a multiskill intellectual and to reveal that his thoughts about science, technology, training scientists and educators were in accordance with their writings and their professional practice in order to build a first story about the life and work of William de La Penha. In this sense, we took the theoretical aspects related to historical research, biographies, intellectual itineraries, files and inventories as sources and historical construction vehicles in order to point out the essential elements to form a profile of the transdisciplinary intellectual historians, ie a profile scientist who carries out the research, management and administration, as well as a committed educator to the on-going training and forming process. The results pointed in different directions, among which we highlight the creation of Seção Guilherme de La Penha at Universidade da Amazonia, producing several articles about the life and work of William de La Penha presented at national and international conferences and the proposal for documentary displays which could contribute to understanding the implementation of a scientific area in Pará State, an area that would not only be restricted to the production of knowledge, but more than that, it would include the spreading, which provides various means, primarily through education. Thus it was possible to ensure that La Penha has an intellectual profile that can be considered a multi-and transdisciplinary intellectual who defends the possibility of forming a scientist one and multiple, non-linear attitudes and dialogues with all other areas in order to be understood under a model scientist for the twenty-first century based on the model clearly inspired by the scientist authors with which he identified throughout their training and professional activities, like the three that stood out in their relationship science: Archimedes, Leonhard Euler and Cliford Ambrose Truesdell
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The presence of pores in ceramics is directly related to the chosen forming process. So, in the starch consolidation method, the ceramics show, after burning, pores with morphology similar to that presented by this organic material. on the other hand, the increase in solid load leads up to alterations in dispersion viscosity, increasing the thermal stresses during drying and sintering processes. In order to verify the solid percentage influence in ceramic final properties, samples were prepared with silicon carbide in different compositions using or not starch as binder agent and pore forming element. The characterization of the ceramic pieces was performed by superficial roughness measurements, porosity besides by optical and scanning electron microscopy. The results showed ceramics with SiC and starch presented physical and microscopic properties slightly higher in relation to those with only ceramic powder in their composition. The presence of organic material, agglomerated and foam during the forming were essential for the final properties of the studied samples.
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Zein films plasticized with oleic acid were formed by solution casting, by the stretching of moldable resins, and by blown film extrusion. The effects of the forming process on film structure were investigated by X-ray diffraction. Wide-angle X-ray scattering (WAXS) patterns showed d-spacings at 4.5 and 10 angstrom, which were attributed to the zein alpha-helix backbone and inter-helix packing, respectively. The 4.5.angstrom d-spacing remained stable under processing while the 10 angstrom d-spacing varied with processing treatment. Small-angle X-ray scattering (SAXS) detected a long-range periodicity for the formed films but not for unprocessed zein, which suggests that the forming process-promoted film structure development is possibly aided by oleic acid. The SAXS d-spacing varied among the samples (130-238 angstrom) according to zein origin and film-forming method. X-ray scattering data suggest that the zein molecular structure resists processing but the zein supramolecular arrangements in the formed films are dependent on processing methods.
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Deposits formed on the surface of. paper were analysed in order to identify the sources of the defects, as well as to solve the problems associated with performance and adjustments at the wet end of the paper forming process. Standard paper samples containing deposits were collected and analysed by comparing the microstructure and composition of the deposit with paper regions adjacent to it. Optical microscopy (OM). energy dispersive X-ray microanalysis (EDX) X-ray powder diffraction (XRD). thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were the techniques used in this study. The results obtained from the EDX, XRD. and TG techniques allowed concluding that the calcium carbonate content in the farm of calcite is 1.6 times higher in the formed deposit them the quantity expected in the standard paper composition. The paper sample microstructure revealed by the SEM images indicates the presence of irregular spherical aggregates up to 20μm in diameter in the deposit region. containing larger amount of calcium carbonate as well as in the regions adjacent to the deposit. These spherical aggregates seem to be absorbed and integrated into the pulp fibres and present characteristics similar to those of partially cooked cationic starch. The analysed deposits are characterised by a dense and thick substance, forming a plate with highly adhesive property. This adhesive substance has a characteristic similar to glue with a large amount of organic matter due to the high weight loss shown by the TG curve. The results are consistent with the interaction ofparticles of negatively charged calcium carbonate and cationic starch, forming sterically stabilized deposits, which firmly adhere to the paper microstructure.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Educação - FCT
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Pós-graduação em Engenharia Mecânica - FEIS
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A liga 6101 (série 6xxx) foi modificada através da adição de cobre nos percentuais de 0,05%Cu e 0,3%Cu, e também de refinadores de grão à base de uma pré-liga Al-Ti-B. As ligas foram caracterizadas termicamente (coeficiente de transferência de calor metal/molde, Velocidade de deslocamento da isoterma liquidus e taxa de resfriamento), mecanicamente (limite de resistência à tração e módulo de tenacidade) e eletricamente (resistência, resistividade e condutividade elétrica) utilizando duas formas de vazamentos: uma sendo através de solidificação em molde unidirecional horizontal e a outra através do molde em “U”. Para a solidificação em molde unidirecional horizontal as caracterizações mostraram-se bastante influenciadas pelos refinadores de grão e pela viscosidade que o cobre exerce na eficiência do contato metal/molde das ligas, alterando significativamente suas propriedades térmicas, mecânicas e elétricas. Por outro lado, na solidificação em molde “U” as ligas foram avaliadas apenas através de caracterização mecânica e elétrica, tendo em vista a preocupação sobre as variáveis do processo de conformação da liga metálica, tais como, a avaliação da taxa de deformação, do limite de resistência a tração, da tenacidade e da resistência, resistividade e condutividade elétrica, do perfil metálico produzido, para corpos de prova de diferentes diâmetros. Para o molde em “U” houve ainda a adição e avaliação de mais duas ligas sendo a Al-0,6Mg-0,4Si-0,1Cu e Al-0,6Mg-0,4Si-0,2Cu. As propriedades mecânicas e elétricas sofreram forte influência do encruamento, do teor de cobre e das microcavidades existentes nas estruturas das ligas.