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Cost modelling for manufacturing of aerospace compositesMa, Weitao January 2011 (has links)
The application of composites has been increasing dramatically in aerospace structures recently, for example, composites have contributed over 50 percent of the structure mass of large transport airplanes Boeing 787 and Airbus 350XWB. However, the further usage has been restricted because of the high material and manufacturing costs. Hence, it is essential to utilize cost estimation tools for accurate cost estimation in the early design stages, and then efficient decisions and design optimizations could be made to reduce the cost of composite products. This research project aims to develop a cost model for aerospace carbon fibre reinforced plastic (CFRP) composites, which will help designers and cost engineers with the cost estimation for composites manufacturing in the early development stages. The main objectives of the research are to: (i) recognise the standard manufacturing stages and activities of CFRP components; (ii) identify the cost drivers of composites manufacturing; (iii) identify the cost estimation relationships; (iv) develop a cost model that can assist designers and engineers with manufacturing cost estimation for CFRP components; (v) validate the developed cost model through case studies and expert judgements. The process of model development was carried out through four main steps: firstly, conducting an integrated understanding of cost modelling for composites manufacturing; secondly, collecting data for cost modelling from industry and existing literature and databases; thirdly, developing the cost model with several function modules and databases; and finally, taking a validation of the developed model. The developed cost model consists of several modules: material selection, process planning, cost estimation, cost reporting and a user friendly interface. Moreover, the selection and planning modules are combined with databases including material and process. The developed model enables the user to estimate the manufacturing cost and process time of CFRP composites, and it can also help designers realize the impact of design changes on the manufacturing cost. The process planning can efficiently help estimators with manufacturing process understanding and accurate time estimation. Quality control activities are time consuming and investment sensitive in composites manufacturing.
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Příprava magnetických a optických nanočástic / Příprava magnetických a optických nanočásticRepko, Anton January 2010 (has links)
Title: Preparation of magnetic and optical nanoparticles Author: Anton Repko Department: Department of Inorganic Chemistry, Faculty of Science, Charles University of Prague Supervisor: RNDr. Daniel Nižňanský, Ph.D. Supervisor's e-mail address: niznansk@natur.cuni.cz Abstract: In the present work we study methods of preparation of magnetic and optical nanoparticles by hydrothermal method. Specifically, we prepared particles of cobalt ferrite (CoFe2O4) and sodium yttrium fluoride (NaYF4) doped by Yb3+ a Er3+ from corresponding nitrates in the system of water - ethanol - oleic acid, and in modified systems. By this method, it is possible to prepare particles of narrow size distribution (monodisperse particles). Pre- pared particles of ferrite show superparamagnetism and particles of NaYF4 up-conversion, i.e. conversion of infrared (980 nm) to visible light. Keywords: nanocrystals, superparamagnetism, up-conversion, CoFe2O4, NaYF4, hydrothermal synthesis
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Conception et caractérisation d'échangeurs-réacteurs à structuration multi-échelle / Design and characterization of exchanger-reactors with multi-scale structuringSaber, Meryem 28 September 2009 (has links)
La présente thèse s’intéresse à la conception et la caractérisation des procédés microstructurés mettant en œuvre des réseaux de microcanaux de différentes dimensions. L’analyse de tels réseaux multi-échelles, représentatifs d’une parallélisastion de microsystèmes élémentaires, a essentiellement servi à identifier les principaux paramètres géométriques et physiques contrôlant les performances de ces réseaux complexes. On a cherché à quantifier l’influence des paramètres géométriques comme le rapport de résistances hydrodynamiques internes, le nombre de canaux et d’échelles opérant ainsi que leur répartition sur le réseau, sur des critères hydrodynamiques comme la maldistribution du fluide et la perte de charge résistive. Il est révélé qu’en fonction des contraintes imposées, un arrangement optimal des canaux sur un nombre pair d’échelles permet de réduire considérablement la maldistribution interne des flux et les pertes de charge résultantes. L’analyse thermique associée à l’analyse hydrodynamique a montré que les performances thermiques des réseaux sont fortement liées à leurs structurations géométriques internes. En présence de réactions catalytiques consécutives, ces mêmes réseaux enregistrent des déviations du rendement du produit désiré. Ces déviations peuvent être levées par une structuration appropriée du réseau catalytique multi-canal. La même architecture de ces réseaux peut être adaptée pour permettre le déroulement des opérations de mélange et/ou des réactions multi-phasiques. Ainsi, pour ces réseaux complexes, où un nombre élevé de variables imbriquées est considéré, des lignes directrices sont ressorties pour aider à leur conception et dimensionnement / This PhD thesis focuses on the design and the characterization of microstructured processes including microchannel networks of various dimensions. The analysis of such multi-scale networks, representative of elementary microsystems parallelization, is mainly used to identify the main geometrical and physical parameters controlling the network performances. Influence of geometrical parameters, such as the internal hydrodynamic resistances ratio, the number of channels and scales and their arrangement in the network, on hydrodynamic criteria like fluid maldistribution and pressure drop is investigated. It is shown that according to some specific constraints, an optimal arrangement of the channels on an even number of scales, allows to reduce significantly the internal flow maldistribution and the consequential pressure losses. The thermal analysis coupled with the hydrodynamic analysis illustrates that the thermal performances of microchannel networks are strongly affected by their internal geometrical arrangement. Nevertheless, the various mixture points located in the network compensate the fluid maldistribution resulting from a non appropriate geometrical arrangement. When consecutive catalytic reactions are performed inside these networks, deviations of the desired product rate can be recorded. These deviations can be reduced by an optimal catalytic network arrangement. The same architecture of these networks is also adapted to allow multi-phase mixing and /or reactions. Thus, using these complex networks, where several variables are considered, guidelines are derived in order to improve their design and their dimensionless
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Imaginando a mulher: Pin-up, da chérette à playmate / Imagining the female: pin-up, of the chérette to playmateSaggese, Antonio José 23 September 2008 (has links)
Análise da produção da imagem da mulher enquanto mercadoria na era moderna. O imaginário erótico na sociedade de consumo, na mídia gráfica do Século XIX ao Século XX. A imagem técnica e suas relações com a pintura acadêmica na representação da figura feminina e do nu, pela fotografia, cinema, ilustração e cartum. A pin-up sua origem e suas variações. / Analysis of the production of the female image as a commodity in modern age. The erotic imagery in the consumer society, in the graphic media from XIX to XX century. The technical image and its relation with the academic painting in the representation of the womens figure and the nude in the photography, cinema, illustration and cartoon. The pin-up, its origins and variations.
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Aceleração do crescimento entre crianças e adolescentes de populações multiétnicas e suas evidências / Accelerating growth among children and adolescents of multiethnic populations and their evidenceGallo, Caroline de Oliveira 10 October 2018 (has links)
Introdução: Déficits de altura-para-idade (DAI) descrevem falhas no crescimento da criança e estão associados a condições de saúde e socioeconômicas. Evidências sugerem que intervenções durante os primeiros 1000 dias de vida são mais efetivas para reduzir a carga global de DAI. Entretanto, há evidências de recuperação do DAI após este período, fenômeno chamado de catch-up growth (CUG). O CUG descreve um rápido crescimento linear que permite o indivíduo acelerar para e, em condições favoráveis, voltar a sua curva de crescimento pré-doença. Contudo, não há uniformidade na definição operacional de CUG e existem divergências acerca do melhor mensurador do CUG, fator decisivo nas conclusões sobre o tema. Objetivos: Analisar evidências de crescimento acelerado entre crianças e adolescentes de populações multiétnicas utilizando distintas formas de mensuração e caracterizar aspectos epidemiológicos do CUG. Métodos: Utilizaram-se bases de dados de populações multiétnicas. Medidas de altura foram convertidas em escore-z a partir do padrão e referência OMS (2006/07). O CUG foi avaliado pelo escore-z altura-para-idade (HAZ) e pela diferença altura-para-idade (HAD), em centímetros, por meio da variação destes índices e pela canalização do crescimento, utilizando três valores de amplitude de canal (0,67, 0,75 e 0,86 desvio-padrão), assim como pela recuperação do DAI inicial. Os efeitos dos fatores associados ao crescimento sobre o CUG foram estimados em modelos de regressão de Poisson e análise multinível. Entre as variáveis independentes configuraram características socioeconômicas, maternas e da criança e variável contextual indicando o nível de desenvolvimento do país. Resultados: Nas coortes Young Lives e nas Filipinas o HAZ declinou nas idades iniciais e aumentou até o último seguimento. O HAD, contudo, indicou aumento do déficit de altura até o último acompanhamento. Em São Paulo e na Grã-Bretanha ambos índices apresentaram incremento entre os períodos inicial e final, indicando melhoria do estado nutricional. Houve desigualdade de ambos indicadores entre os estratos socioeconômicos. Maiores prevalências de DAI ocorreram nos países menos desenvolvidos, em áreas rurais, em domicílios sem acesso a saneamento e em indivíduos com baixo peso ao nascer, episódios de diarreia na infância e cujas mães possuíam baixa estatura e menor escolaridade; houve relação dose-resposta com o quinto de renda. Houve substancial recuperação do DAI em todos países, com maiores taxas nos mais desenvolvidos. A incidência de CUG a cada cinco anos variou de 7,9% a 15,4% entre 1 e 12 anos de idade e foi 1% nas Filipinas entre 0 e 19 anos. Em todos os estudos, o grupo com DAI inicial obteve as maiores incidências. A maior parte dos indivíduos que se recuperaram do DAI inicial apresentaram crescimento acelerado considerando os três limites de canalização. O número de eventos de CUG durante a trajetória de crescimento foi o principal determinante da ocorrência de CUG final e recuperação do DAI, bem como o grau de DAI inicial e o estrato socioeconômico. Os efeitos randômicos sobre estes desfechos variaram em torno de 9%. Conclusões: Os resultados indicam potencial para o CUG e recuperação do DAI. O uso de distintos mensuradores levou a interpretações divergentes acerca da ocorrência de CUG. / Introduction: Height-for-age déficits (stunting) describe failures in child growth and are associated with health and socioeconomic conditions. Evidence suggests that interventions during the first 1000 days of life are more effective in reducing the overall burden of stunting. However, there is evidence of recovery of stunting after this period, a phenomenon called catch-up growth (CUG). CUG describes a rapid linear growth that allows the individual to accelerate to and, under favorable conditions, return to their pre-disease growth curve. However, there is no uniformity in the operational definition of CUG and there are disagreements about the best CUG measurer, a decisive factor in the conclusions about the subject. Objectives: To analyze evidence of accelerated growth among children and adolescents of multiethnic populations using different forms of measurement and to characterize the epidemiological aspects of CUG. Methods: Databases of multiethnic populations were used. Height measurements were converted to z-score from the WHO standard and reference (2006/07). The CUG was evaluated by height-for-age z-score (HAZ) and height-for-age difference (HAD), in centimeters, by variation of these indices and by canalisation of growth, using three values of amplitude (0.67, 0.75 and 0.86 standard deviation), as well as by recovery of the initial stunting. The effects of growth-related factors on CUG were estimated in Poisson regression models and multilevel analysis. Among the independent variables configured socioeconomic, maternal and child characteristics and a contextual variable indicating the level of development of the country. Results: In the Young Lives Cohorts and in the Philippines HAZ declined in the early ages and increased until the last follow-up. HAD, however, indicated an increase in height deficit until the last follow up. In São Paulo and Great Britain, both indexes showed an increase between the initial and final periods, indicating an improvement in nutritional status. There was inequality of both indicators among the socioeconomic strata. Higher prevalence of stunting occurred in less developed countries, in rural areas, in households without access to sanitation, and in individuals with low birth weight, episodes of childhood diarrhea and whose mothers had short stature and lower schooling; there was a dose-response relationship with the income. There was a substantial recovery of stunting in all countries, with higher rates in the most developed. The incidence of CUG every five years ranged from 7.9% to 15.4% between 1 and 12 years of age and was 1% in the Philippines between 0 and 19 years. In all studies, the group with initial stunting had the highest incidence. Most of the individuals who recovered from the initial stunting presented accelerated growth considering the three canalisation limits. The number of CUG events during the growth trajectory was the main determinant of the occurrence of final CUG and recovery of the stunting, as well as the degree of initial stunting and the socioeconomic stratum. The random effects on these outcomes varied around 9%. Conclusions: The results indicate potential for CUG and recovery of stunting. The use of different measurers led to divergent interpretations regarding the occurrence of CUG.
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Uniformização local: redução ao caso de valorizações de posto um / Local uniformization: reduction to the case of valuations of rank oneMoraes, Michael Willyans Borges de 16 August 2017 (has links)
Este trabalho trata da uniformização local, que é um passo do método de Zariski para provar resolução de singularidades em variedades algébricas. O método consiste numa abordagem por teoria de valorizações, e esta dissertação se baseia no artigo [NS], de Novacoski e Spivakovsky, que consiste em reduzir a prova da uniformização local para valorizações de qualquer posto, a provar apenas para os casos de posto um. / This work deals with local uniformization, which is a step in the method of Zariski to prove resolution of singularities for algebraic varieties. The method consists in an approach using valuation theory and this dissertation is based on the paper [NS], by Novacoski and Spivakovsky, which consists in reduce the proof of local uniformization for all cases to prove only the cases of rank one.
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Estratégias nacionais de catch-up aeronáutico / National strategies of aeronautical catch-upDemetrio Gaspari Cirne de Toledo 05 July 2013 (has links)
Esta tese compara as estratégias de catch-up aeronáutico de Brasil, Argentina, Indonésia, Japão, China e Rússia ao longo da segunda metade do século XX e começos dos anos 2000. Mais especificamente, examina os modos como esses países tentaram desenvolver empresas capazes de projetar, produzir e comercializar aviões civis para o mercado interno e externo. Partindo das noções de sistema tecnoprodutivo, distância da fronteira tecnológica e catch-up industrial, foi desenvolvido um modelo analítico dos fatores que explicam o sucesso ou o fracasso de cada um dos casos estudados. À reconstrução histórica segui-se a comparação formal dos casos por meio de um modelo de análise qualitativa comparada (QCA) composto por três dimensões: estratégia de aprendizagem tecnoprodutiva; fatores institucionais; fator empresarial. Os resultados da reconstrução histórica e do modelo de análise qualitativa comparada indicam que a estratégia de aprendizagem tecnoprodutiva e os fatores institucionais são aspectos altamente relevantes da explicação do sucesso ou fracasso das estratégias de catch-up aeronáutico. No entanto, apenas os sistemas tecnoprodutivos aeronáuticos que lograram desenvolver o fator empresarial, ou seja, formar uma empresa comercialmente orientada responsável pelo desenvolvimento, produção e comercialização de aviões, obtiveram pleno sucesso em suas tentativas de catch-up. A tese pretende, além de formalizar um modelo das estratégias de catch-up, contribuir para a reflexão mais ampla sobre as possibilidades de desenvolvimento industrial disponíveis aos países que atualmente se encontram a grande distância da fronteira tecnoprodutiva contemporânea. / This thesis compares aeronautical catch-up strategies in Brazil, Argentina, Indonesia, Japan, China and Russia during the second half of the 20th century and the beginning of the 2000s. In particular, it examines the ways in which these countries have tried to develop companies capable of designing, producing and selling civilian aircraft for domestic and foreign markets. Building on the notions of technoproductive system, distance to the technological frontier and industrial catch-up, we develop an analytical model of the factors that explain the success or failure of each of the cases examined. The historical reconstruction of the cases is followed by a formal comparison of cases by means of a model of qualitative comparative analysis (QCA) composed of three dimensions: technoproductive learning strategy; institutional factors; firm factor. The results of the historical reconstruction and of the comparative qualitative analysis indicate that technoproductive learning strategy and institutional factors are highly relevant aspects in explaining the success or failure of each aeronautical catch-up strategy. However, it is only the technoproductive aeronautical systems that succeed in developing the firm factor, ie, in forming a commercially oriented firm responsible for the development, production and commercialization of civil aircraft, that achieve full success in their attempts to catch-up. In addition to formalizing a model of catch-up strategies, this thesis contributes to a broader discussion on the possibilities of industrial development available to countries which are currently at a significant distance from the contemporary technoproductive frontier.
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Estratégias nacionais de catch-up aeronáutico / National strategies of aeronautical catch-upToledo, Demetrio Gaspari Cirne de 05 July 2013 (has links)
Esta tese compara as estratégias de catch-up aeronáutico de Brasil, Argentina, Indonésia, Japão, China e Rússia ao longo da segunda metade do século XX e começos dos anos 2000. Mais especificamente, examina os modos como esses países tentaram desenvolver empresas capazes de projetar, produzir e comercializar aviões civis para o mercado interno e externo. Partindo das noções de sistema tecnoprodutivo, distância da fronteira tecnológica e catch-up industrial, foi desenvolvido um modelo analítico dos fatores que explicam o sucesso ou o fracasso de cada um dos casos estudados. À reconstrução histórica segui-se a comparação formal dos casos por meio de um modelo de análise qualitativa comparada (QCA) composto por três dimensões: estratégia de aprendizagem tecnoprodutiva; fatores institucionais; fator empresarial. Os resultados da reconstrução histórica e do modelo de análise qualitativa comparada indicam que a estratégia de aprendizagem tecnoprodutiva e os fatores institucionais são aspectos altamente relevantes da explicação do sucesso ou fracasso das estratégias de catch-up aeronáutico. No entanto, apenas os sistemas tecnoprodutivos aeronáuticos que lograram desenvolver o fator empresarial, ou seja, formar uma empresa comercialmente orientada responsável pelo desenvolvimento, produção e comercialização de aviões, obtiveram pleno sucesso em suas tentativas de catch-up. A tese pretende, além de formalizar um modelo das estratégias de catch-up, contribuir para a reflexão mais ampla sobre as possibilidades de desenvolvimento industrial disponíveis aos países que atualmente se encontram a grande distância da fronteira tecnoprodutiva contemporânea. / This thesis compares aeronautical catch-up strategies in Brazil, Argentina, Indonesia, Japan, China and Russia during the second half of the 20th century and the beginning of the 2000s. In particular, it examines the ways in which these countries have tried to develop companies capable of designing, producing and selling civilian aircraft for domestic and foreign markets. Building on the notions of technoproductive system, distance to the technological frontier and industrial catch-up, we develop an analytical model of the factors that explain the success or failure of each of the cases examined. The historical reconstruction of the cases is followed by a formal comparison of cases by means of a model of qualitative comparative analysis (QCA) composed of three dimensions: technoproductive learning strategy; institutional factors; firm factor. The results of the historical reconstruction and of the comparative qualitative analysis indicate that technoproductive learning strategy and institutional factors are highly relevant aspects in explaining the success or failure of each aeronautical catch-up strategy. However, it is only the technoproductive aeronautical systems that succeed in developing the firm factor, ie, in forming a commercially oriented firm responsible for the development, production and commercialization of civil aircraft, that achieve full success in their attempts to catch-up. In addition to formalizing a model of catch-up strategies, this thesis contributes to a broader discussion on the possibilities of industrial development available to countries which are currently at a significant distance from the contemporary technoproductive frontier.
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Avaliação de novos processos de limpeza para quantificação de pireno em amostra de mexilhão / Evaluation of new cleaning processes for quantification of pyrene in samples of musselsPriscila Mendonça de Andrade 27 February 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os hidrocarbonetos policíclicos aromáticos (HPA) constituem um grupo de poluentes ambientais persistentes são moléculas com dois ou mais anéis aromáticos condensados, pouco solúveis em água e estão presentes no ambiente como resultante de processos naturais e também de atividades antrópicas; desta forma, os HPA podem ser encontrados em diversas matrizes ambientais. No presente trabalho foram utilizados mexilhões da região de Búzios, no Estado do Rio de Janeiro. Esse organismo foi selecionado devido à facilidade de acumulação de HPA nos tecidos, decorrente das propriedades hidrofóbicas dos HPA. O presente projeto teve como objetivo estudar um novo material de limpeza capaz de minimizar os compostos interferentes da matriz. Os cartuchos de SPE Florisil 5 g, são convencionalmente usados na limpeza de amostras de organismos, porém para diminuir os custos foram testados outros materiais adsorventes que pudessem ser eficientes na remoção dos interferentes presentes nos tecidos de mexilhão. Sendo assim, na etapa de limpeza conhecida como clean-up, foi estudada a recuperação do pireno após a extração por micro-ondas através de duas abordagens diferentes; a) utilização de cartuchos de SPE comerciais de 5 g de Florisil; b) cartuchos preenchidos com argila comercial K-10 bentonite, simulando os cartuchos comerciais. A recuperação e eficiência dos procedimentos de limpeza foram testadas e comparadas. A clean-up com argila K-10 apresentou uma recuperação de até 77% de pireno, sendo eficiente na remoção de compostos de colesteróis; confirmando a eficiência do material escolhido para a limpeza da amostra. A técnica de Cromatografia Gasosa e detecção por Espectrometria de Massas (GC-MS) foi aplicada para identificação e quantificação do contaminante pireno no extrato finaa / Polycyclic aromatic hydrocarbons (PAH) are a group of persistent environmental pollutants are molecules containing two or more condensed aromatic rings, little soluble in water and are present in the environment as a result of natural processes and human activities; in this way, the HPA can be found in various environmental matrices. In this work we used mussels in Búzios, Rio de Janeiro State. That body was selected due to the ease of accumulation of HPA in the tissues, due to the hydrophobic properties of HPA. This project aimed to study a new cleaning material able to minimize interfering compounds of the array. The 5 g Florisil SPE cartridges, are conventionally used in the cleaning of samples of organisms, however for lower costs have been tested other adsorbent materials which could be effective in the removal of the present in the tissues of mussels interfering. Therefore, in step of cleaning known as clean-up, recovery of pyrene was studied after extraction by microwave through two different approaches; a) use of commercial SPE cartridges 5 g of Florisil; b) cartridges filled with K-10 clay bentonite commercial, simulating the commercial cartridges. Recovery and efficiency of cleaning procedures were tested and compared. The clean-up with K-10 clay presented a recovery of up to 77% of pyrene, being effective in removing compounds of cholesterols; confirming the efficiency of the chosen material for cleaning of the sample. The technique of gas chromatography and detection by mass spectrometry (GC-MS) was applied for identification and quantification of contaminant pyrene in the final extract
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Podnikatelský plán MSP / Business plan of SMEMachová, Adéla January 2010 (has links)
Master's thesis on the topic Business plan of SME introduces theoretical description of business plan, where it describes reasons of being of the business plans and entrepreneurship and then individual points of business plan. That includes setting up the targets of the company, description of business activities using different methods till financing. Practical part creates new business plan. This plan starts a restaurant as a first step for future franchise chain. The target of the thesis is development of business plan and verifying it's feasibility. Theoretical part will be straightly implemented to the development of the practical part.
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