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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Caracterização de biomassa lignocelulósica utilizando técnicas de ressonância magnética nuclear do estado sólido (SSNMR) / Characterization of lignocellulosic biomass using solid-state nuclear magnetic resonance techniques

Oigres Daniel Bernardinelli 29 January 2016 (has links)
Nesta tese, a ressonância magnética nuclear do estado sólido (SSNMR) foi utilizada para estudar a composição química e estrutura dos componentes da parede celular de plantas. Visando contribuir no desenvolvimento de estratégias de despolimerização da biomassa, SSNMR foi inicialmente utilizada para estudar efeitos dos pré-tratamentos químicos e físicos, e da ação de enzimas sobre algumas biomassas. Os resultados mostraram que, em baixas concentrações, tratamentos ácidos são altamente efetivos na remoção das frações de hemicelulose, com pouco efeito nas frações de lignina e celulose. Já tratamentos alcalinos promovem eficiente deslignificação da biomassa, sendo que a mínima concentração da solução alcalina necessária para obter a máxima deslignificação depende do tipo de biomassa e da temperatura do tratamento. Os estudos por SSNMR foram correlacionados com estudos por outras técnicas, contribuindo para um entendimento mais profundo sobre o efeito dos pré-tratamentos e da hidrolise enzimática em diferentes biomassas. Outra parte da tese aborda a determinação da cristalinidade de celulose nativa (não extraída) de biomassa de bagaço de cana-de-açúcar. Utilizando a técnica de polarização cruzada em múltiplas etapas (Multi-CP) e um procedimento de subtração espectral, foi possível isolar os sinais de RMN da celulose nativa e a partir daí avaliar o índice de cristalinidade (CI). Esse método foi utilizado para avaliar o CI da celulose nativa de bagaço de cana-de-açúcar submetido à pré-tratamentos com H2SO4 e NaOH e os resultados não mostraram variações significativas do CI da celulose nas concentrações utilizadas, apesar do aumento da eficiência da hidrólise. Assim, ao contrário de muitos trabalhos encontrados na literatura, não parece que a cristalinidade da celulose seja um fator primordial no aumento de eficiência da hidrólise enzimática. Na parte final da tese, as interações intermoleculares entre os dois principais polissacarídeos da biomassa: celulose e xilano foram investigadas utilizando uma variedade de técnicas avançadas de RMN bidimensional. Neste trabalho, a arquitetura molecular de hastes de plantas de Arabidopsis Thaliana, sem nunca serem seca foi estudada. Utilizando a técnica refocused J-INADEQUATE (Increadible Natural Abundance Double Quantum Transfer Experiment via J coupling) observamos dois conjuntos de deslocamentos químicos distintos para o xilano, sendo um deles coincidente com aquele observado em solução. Em seguida, utilizamos experimentos SSNMR com o intuito de investigar se algum desses domínios de xilano estaria vinculado com a celulose. Experimentos CP-PDSD (Proton Driven Spin Diffusion detected via 13C through Cross-Polarization) demonstram a existência de proximidade espacial entre o novo domínio do xilano e o domínio da celulose. A comparação de resultados entre as amostras de padrão e o seu mutante deficiente em celulose (irx3) indicaram que o xilano com novo deslocamento químico é fortemente dependente da presença de celulose. A análise da mobilidade molecular pela técnica Dipolar Chemical Shift Correlation (DIPSHIFT), mostrou que as moléculas do novo domínio do xilano são altamente rígidas - uma característica partilhada com a celulose. Combinados, esses dados fornecem evidências de uma arquitetura molecular específica entre os dois polissacarídeos majoritários da parede celular. / Solid-state nuclear magnetic resonance (SSNMR) was used to study the chemical composition and structure of plant cell wall components. Aiming the development of depolymerization strategies, SSNMR was initially used to study the effects of chemical and physical pre-treatments, as well as the enzymatic action on the structure and composition of biomasses. The results showed that, at low concentrations, pre-treatments with acids are highly effective for removal of hemicellulose without significant effect on lignin and cellulose. In turn, the alkaline pre-treatment promotes efficient delignification of the biomass. The minimum concentration of the alkaline solution required to achieve the maximum delignification depends on the type of biomass and treatment temperature. SSNMR studies were correlated with studies using other techniques, contributing to an in-depth understanding of the effect of pre-treatments and enzymatic hydrolysis in different biomasses. Another part of the thesis discusses is the determination of native cellulose crystallinity (not extracted) of sugarcane bagasse biomasses. Using the cross-polarization technique in multiple blocks (Multi-CP) and a spectral subtraction approach, it was possible to isolate the NMR signals of the native cellulose and to evaluate the crystallinity index (CI). This method was used to accessof the CI of cellulose in sugarcane bagasse samples pre-treated with H2SO4 and NaOH. The results did not show significant variations of the cellulose CI, at the concentration used here, despite the increase in the hydrolysis efficiency. Thus, in contrast to some studies in the literature, it does not appear that the crystallinity of cellulose is a primary limiting factor concerning the enzymatic hydrolysis efficiency in biomasses. In the final part of this thesis, the intermolecular interactions between the two main polysaccharides of the plant cell wall, cellulose and xylan, were investigated using advanced two-dimensional NMR techniques. The molecular architecture of 13C labelled never-dried Arabidopsis Thaliana stems was studied. Using refocused J-INADEQUATE (Increadible Natural Abundance Double Quantum Transfer Experiment via J coupling) we observed two distinct chemical shifts in xylan, one of which coincides with that observed in solution. Next, we used SSNMR experiments toinvestigate the interaction between the novel xylan and cellulose domains. CP-PDSD (Proton Driven Spin Diffusion detected via 13C through Cross-Polarization) experiments demonstrated spatial proximity between the new xylan and cellulose domains. The same approach was used to study cellulose deficient (irx3) mutants and the comparison between the results indicate that the new xylan domain is cellulose-dependent. Dipolar Chemical Shift Correlation (DIPSHIFT) experiments were performed to analyse the molecular mobility of these polysaccharides showing that the novel xylan is highly rigid - a characteristic which is shared with cellulose. Combined, these data provide evidence for a specific molecular architecture between the two most common polysaccharides in plant cell walls.
192

Produção de biomassa e eficiência no uso da água para oito variedades de cana-de-açúcar irrigadas por gotejamento em dois ciclos de cultivo / Biomass production and efficient use of water for eight varieties of sugarcane drip irrigated in two crops

Lucas da Costa Santos 15 April 2016 (has links)
A irrigação quando bem manejada, pode minimizar os riscos econômicos da atividade sucroalcooleira, particularmente em safras com presença de instabilidade climática onde a restrição hídrica, promovida pela diminuição no volume de chuvas, pode reduzir a produtividade dos canaviais. Dentre as ferramentas disponíveis para a gestão eficiente da água na agricultura irrigada, a técnica de irrigação sob déficit pode se tornar uma escolha acertada para a cana-de-açúcar, desde que sejam identificadas as fases fenológicas e épocas de cultivo onde a limitação da oferta de água não implique em reduções antieconômicas no rendimento da cultura. Diante disso, a hipótese que norteia essa pesquisa, é a de que existe uma estratégia de irrigação sob déficit, que associada a uma variedade com características específicas, possibilite a expressão de indicadores de produtividade tão satisfatórios quanto os obtidos em condições de irrigação plena. Nessa linha, os objetivos da pesquisa envolveram o estudo da dinâmica foliar, acúmulo e particionamento de biomassa e ainda, índices de produtividade da água para biomassa, açúcar e etanol de 1ª e 2ª geração de oito variedade de cana-de-açúcar, submetidas a diferentes condições de disponibilidade hídrica no solo em dois ciclos de cultivo (cana-planta e cana-soca). A pesquisa foi realizada na Escola Superior de Agricultura \"Luiz de Queiroz\", em Piracicaba/SP, onde foram estudados os dois primeiros ciclos de cultivo da cana-de-açúcar, sendo estes abordados nesta tese como Experimento 1 (cana-planta) e Experimento 2 (cana-soca). O delineamento experimental adotado para ambos os ciclos foi o de blocos casualizados, com três blocos completos. Os tratamentos foram compostos por três fatores em esquema de parcelas sub-subdivididas. Estas parcelas foram formadas por duas plantas (touceiras) alocadas em um vaso com aproximadamente 330 litros de solo. No Experimento 1, foram estudados três fatores, sendo o primeiro e segundo com quatro níveis e o terceiro com oito (4x4x8), totalizando assim 128 tratamentos, sendo eles: quatro níveis de irrigação ao longo do ciclo (125, 100, 75 e 50% da ETc); oito variedades comerciais de cana-de-açúcar e quatro procedimentos de maturação, impostos por meio de variações na intensidade do déficit hídrico aplicado. Para o Experimento 2, substitui-se o fator Maturação por Épocas de Corte, o qual consistiu em colheitas de um quarto do experimento a cada 90 dias. Os resultados encontrados apontaram que a área foliar responde positivamente a maior disponibilidade hídrica no solo, tendo sido verificado uma relação proporcional entre estes. Quanto ao acúmulo de biomassa, verificou-se que para as oito variedades estudadas houve incremento de biomassa a medida em que se aumentou o volume de água disponibilizado às variedades. No tocante ao particionamento, as folhas foram os drenos principais de fotoassimilados da planta até os 100 dias de cultivo, sendo que após este período, os colmos ocuparam o lugar de dreno preferencial. Os indicadores de produtividade da água apresentaram diferenças significativas para o fator lâmina, o que indica a existência de cultivares de cana-de-açúcar mais eficientes no uso da água. Por fim, observou-se que a produtividade da água para etanol total apresentou valores expressivos, com média para essa variável igual a 1,81 L m-3, o que denota o potencial de rendimento de etanol (1G + 2G) a partir da cana-de-açúcar quando é adotado o aproveitamento integral das plantas. / Irrigation when managed, can minimize the economic risks of sugarcane activity, particularly in crops with the presence of climatic instability where water restriction, promoted by the decrease in rainfall, can reduce the productivity of sugarcane fields. Among the tools available to effectively irrigation manage, under deficit irrigation technique can become a right choice for sugarcane, provided they are investigated phenological stages and growing seasons where the limitation of the supply of water does not lead to uneconomical reductions in crop yield. Therefore, the hypothesis that guides this work is that there is a strategy of deficit irrigation, which associated with a cultivar with specific characteristics, enables the expression of productivity indicators as satisfactory as those obtained in full irrigation conditions. In this context, the objectives of this research involves the study of leaf dynamics, biomass accumulation and partitioning and also the water productivity indices for biomass, sugar and ethanol from 1st and 2nd generation of eight variety of sugarcane, subject to different conditions of soil water availability in two crop cycles (cane plant and ratoon crop). The research was conducted at the College of Agriculture \"Luiz de Queiroz\", Piracicaba-SP, Brazil. The research was conducted in the first two cycles of cultivation of sugarcane, which are named in this thesis as Experiment 1 (plant crop) and Experiment 2 (ratoon crop). The experimental design adopted for both cycles was blocks randomized, with three complete blocks. The treatments were three factors in scheme of sub-split plot. These plots were formed by two plants (clumps) placed in a pot with about 330 liters of soil. In Experiment 1, three factors were studied, the first and second with four levels and the third with eight (4x4x8), totalizing 128 treatments, as follows: four levels of irrigation throughout the cycle (125, 100, 75 and 50% ETc); eight commercial varieties of sugarcane and four maturity procedures imposed by means of variations in the intensity of water deficit applied. For Experiment 2, the maturation factor was replace for Seasons Court, which consisted in harvests of a quarter of the experiment every 90 days. The results showed that the leaf area responds positively to greater soil water availability, having been verified a proportional relationship between these variables. For the biomass accumulation, it was found, for the eight varieties studied, an increment of biomass while was increase the volume of water available for the varieties. Regarding the partitioning, the leaves were the preferred structures of the plant until the 100 days of cultivation, and after this period, the stems took the place of preferred drain. Water productivity indicators showed significant differences for the irrigation depth factor, which indicates the existence of sugarcane cultivars water use more efficient. Finally, it was observed that the total water productivity to ethanol showed significant values, with a mean for that variable equal to 1.81 L m-3, which shows the ethanol yield potential (1G + 2G) from sugarcane when it adopted the overall use of plants.
193

Redes de inovação em etanol de segunda geração / Innovation Networks in Second-Generation Ethanol

Luiz Gustavo Antonio de Souza 26 July 2013 (has links)
No campo da pesquisa em etanol de segunda geração (lignocelulósico), o Brasil mostra-se como um ator em potencial para a transformação e difusão da ciência em tecnologia. A produção em escala comercial - em especial na fronteira da inovação em etanol lignocelulósico e dos novos produtos oriundos desta conversão - requer alta tecnologia para o desenvolvimento de produtos e processos, matéria-prima disponível e viável, além de um ambiente institucional favorável. Esses fatores colocam o setor sucroenergético brasileiro em posição de destaque e justificam a questão central desta tese que é analisar - sob a perspectiva dos avanços científicos nacionais para o etanol de segunda geração e de seu potencial inovativo - o grau de desenvolvimento do Sistema Nacional de Inovação (SNI) com base na articulação existente entre as pesquisas realizadas por brasileiros em comparação com as realizadas por outros países e em específico os Estados Unidos. A abordagem teóricoconceitual e metodológica estrutura-se nos conceitos da economia evolucionista, subjacentes à formação de Redes de Inovação. Há robustas evidências que mostram que a colaboração científica em redes correlaciona-se positivamente com a difusão do conhecimento científico. As patentes ao assimilarem o conhecimento científico disponível permitem criar novos padrões tecnológicos, novos produtos e processos. Mas também, podem direcionar o fluxo de conhecimento criando uma trajetória tecnológica, ou seja, o caminho realizado para chegar-se em determinada patente. O conhecimento acumulado em determinada patente é representado pelas patentes que a originaram e que envolve diversos setores e atividades. Assim as Redes de Inovação na ótica evolucionista podem ser consideradas indicadores de inovação de determinada atividade ou produto, proxy, para o grau de desenvolvimento de um SNI. Neste cenário, são utilizados dois procedimentos metodológicos complementares, que permitem entender a dinâmica da produção científica e da inovação: a) Redes de Inovação em publicações para a colaboração científica entre países, instituições, KeyWord Plus e citações; e b) Redes de Inovação em patentes para as áreas de aplicação através do IPC8. Portanto, na ótica do desenvolvimento de um SNI, contam principalmente: o grau de colaboração científica, relevância e inserção. Apesar do SNI em etanol de segunda geração possuir elementos necessários para a transformação da ciência em tecnologia, observou-se baixo grau de desenvolvimento em reflexo às seguintes características: a) um baixo grau de colaboração científica internacional em comparação com os Estados Unidos e o Mundo; b) os esforços gerados não estão alinhados com o gargalo tecnológico do etanol de segunda geração; c) há apenas uma instituição representativa no cenário internacional, d) existe uma relação fraca entre universidade-governo-empresa; e) o potencial de difusão do conhecimento não é explorado, seja na forma de publicações científicas quanto na forma de patentes. Conclui-se que o SNI em etanol de segunda geração no Brasil está desenvolvendose, mas com baixa articulação com pesquisadores internacionais, além de uma baixa interação universidade-governo-empresa. Os esforços indicam que o Brasil irá especializar-se na fermentação, processo em que já possui conhecimento acumulado. / In the research area of second generation ethanol (lignocellulosic), Brazil has been shown as a potential actor for changing and spreading the science through technologies. The commercial scale of production - especially in the innovation frontier in lignocellulosic ethanol and new products from this conversion - requires high technology for products and processes development, available and feasible raw materials, plus a favorable institutional environment. These factors place the Brazilian sugarcane industry in a prominent position and justify the central question of this thesis which is to analyze - from the perspective of national scientific advances in second generation ethanol and its innovative potential - the development degree of a National Innovation System (NIS) based on the articulation between researches conducted by Brazilians in the comparison to researches made by other countries, specific by the United States. The theoretical-conceptual and methodological framework is based on evolutionary economics concepts, underlying the Innovation Networks formation. There is a robust evidence that shows the scientific collaboration though networks are positively correlated with the spread of scientific knowledge. Patents in the process of assimilating available scientific knowledge allow to create new technological standards, new products and processes. But also can direct the knowledge flow by creating a technological path, in other words, the path taken to arrive in certain patent. The accumulated knowledge in a particular patent is represented by patents which have originated and that involving different sectors and activities. Thus the Innovation Networks in an evolutionary perspective can be considered as measures of the innovation of a particular activity or product, indeed a proxy for the development degree of the NIS. In this scenario, it was used two complementary methodological procedures, which allow to understand the dynamics of scientific production and innovation: a) Innovation Networks in publications for the scientific collaboration between countries, institutions, KeyWord Plus and citations and b) Innovation Networks in patents for some application areas using IPC8 class. Therefore, in the sight of development of NIS rely mainly: the scientific collaboration degree, relevance and insertion. Despite the NIS in second generation ethanol has necessary elements to change the science and technology, it was observed a low development degree which reflects the following characteristics: a) low degree of international scientific collaboration in comparison with the United States and World; b) efforts generated are not aligned with the technological bottleneck in second generation ethanol; c) only one representative institution in the international scenario; d) weak relationship between university-government-enterprise, e) potential of conversion of knowledge is not exploited, either in the form of scientific publications and in the form of patents. It was concluded that the NIS on second generation ethanol in Brazil is developing, but with low articulation with international researchers, besides a low university-government-enterprise interaction. Efforts indicate that Brazil will specialize in the fermentation, process that has already accumulated knowledge.
194

O deserto de uma metassemântica esconde tamareiras em flor : o legado translinguístico de Émile Benveniste

Bressan, Nilvia Thaís Weigert January 2010 (has links)
A presente pesquisa tem como fundamento epistemológico a Teoria da Enunciação de Émile Benveniste e visa à elaboração de uma metassemântica. Esta noção é nomeada no texto Semiologia da língua, quando Benveniste concebe a ultrapassagem do signo saussuriano como princípio único por duas vias: na análise intralinguística, pelo discurso, o semântico; na análise translinguística, pela elaboração de uma metassemântica que se construirá sobre a semântica da enunciação e será uma semiologia de segunda geração. O método de análise define a partir do estudo intrateórico de Problèmes de linguistique générale, 1, e Problèmes de linguistique générale, 2, seis princípios que possibilitam a análise translinguística no campo metassemântico. São: 1- A metassemântica é uma semiologia de segunda geração: tem como objeto o estudo das relações que se estabelecem entre sistemas semióticos linguísticos e não linguísticos. 2- A metassemântica é a análise das formas complexas do discurso: é a análise de qualquer fato humano, em que seja possível construir a relação entre o método global de apreensão do sentido e o método analítico, tendo por base a semântica da enunciação. 3- A metassemântica tem forma e sentido: sentido e forma são as necessárias faces do importante problema da significação, são noções gêmeas. 4- A metassemântica tem níveis de análise: a noção de nível permite que se reconheça, na complexidade das formas, a arquitetura singular das partes e do todo. 5- A metassemântica possibilita a construção de diversos aparelhos de enunciação: sistemas semióticos não linguísticos estabelecem relações que se definem por enunciações não linguísticas. 6- A metassemântica é sempre uma interpretação parcial do analista: o analista tem uma condição espaço-temporal diferente da condição espaçotemporal de seu objeto de análise. A pesquisa conclui que foi elaborada a metassemântica da metassemântica. / This research is epistemologically based on the Enunciation Theory of Émile Benveniste and proposes to achieve a metasemantics. This notion appears in the text Semiology of the language, when Benveniste conceives two ways to overthrown Saussurian sign as the only principle. Firstly, in the intralinguistic analysis, the discourse, the semantics. Secondly, in the translinguistic analysis by the elaboration of a metasemantics that will be built on the enunciation semantics and it will be a second generation semiology. The method of analysis defines, through an intratheorical study of Problèmes de linguistique générale 1, and Problèmes de linguistique générale 2, six principles that allow the translinguistc analysis in the metasemantics field. They are: 1- Metasemantics is a second generation semiology: its object of study is the relationship between linguistic and non-linguistic semiotic systems. 2- Metasemantics is the analysis of complex forms of discourse: it is the analysis of any human fact in which it is possible to reconstruct the relation between the global method of capturing the meaning and the analytical method based on the enunciation semantics. 3- Metasemantics has form and meaning: meaning and form are the two faces of signification, two twinned notions. 4- Metasemantics presents levels of analysis: this concept is the condition to recognize unique architectures of complex forms partially or as a whole. 5- Metasemantics is the possibility of the construction of several apparatus of enunciation: non-linguistic semiotic systems establish relations capable to allow non-linguistic enunciations. 6- Metasemantics is always a partial interpretation of the analyst: the space-time of the analyst is not the same space-time of his/her object. As conclusion, this research has developed the metasemantics of the metasemantics.
195

Icke-religiositetens (o)lika uttryck : En komparativ sekundäranalys mellan icke-religiösa etniskt svenska och icke-religiösa andra generationens invandrare

Mukhtar, Tania January 2018 (has links)
The group known as “non-religious” have in recent time received attention in sociology of religion due to the need of presenting a more accurate and nuanced image of these individuals.  In the following study, young adults who ascribe themselves as religious to a low degree are investigated through quantitative analysis on previously collected survey material from the project Religion som resurs? (2008).  The study examines what reasons the respondents have stated for assigning themselves a religious affiliation, and to what degree they value the importance of religious tradition in their lives. Furthermore, the study includes a comparative analysis of two non-religious groups which were ethnic Swedes and Swedish born second-generation immigrants whose parents originate from outside of Scandinavia. The purpose of this comparison is to detect whether non-religiosity is expressed differently depending on ethnic background. Finally, the study also examines how the two groups differ in the degree of religious socialisation during their childhood years. Due to restrictions in method and material, this study can only show correlation or lack thereof in regard to the respondents’ answers, rather than explain what the causes behind the differences between the two non-religious groups are. The results were constructed through cross-tabulation of the two groups and six questions from the mentioned survey. In analysing the results, the theories used are socialisation theory as it is expressed by Berger & Luckman, but more so theories developed by Day (2011) from her qualitative study. The analysis uses Days categorisation of nominalist identities, belief orientations and the term which she calls performative belonging. The results of this essay show that the majority of both groups did not grow up exposed to religious socialisation, however a larger share of the second-generation immigrants than the ethnic Swedes stated that they did. Furthermore, almost twice as many second-generation immigrants than ethnic Swedes ascribe themselves a religious affiliation to a high degree. As for why the respondents ascribe themselves a religious affiliation, the reasons, and the degree of which the respondents agree to these reasons, differ slightly between the two groups. The biggest differences which can be seen is that the second-generation immigrants ascribe themselves a religion based on their relationships with family. Finally, regarding the respondents’ opinions on tradition, the results show that they have varied opinions on the question of how important traditions are, but that religious tradition largely does not affect their life-view.
196

Etude des critères de seconde génération de la stabilité du navire à l'état intact / An analysis on second generation intact stability criteria

Ariffin, Arman 09 June 2017 (has links)
Le Sous-comité de la conception et de la construction navale de l'Organisation maritime internationale (OMI) a entrepris l'élaboration de critères de stabilité intacts de deuxième génération (SGISC). Le SGISC est une règle supplémentaire qui complète les règles actuelles.En outre, ces critères sont structurés en trois niveaux, à savoir le premier niveau, le deuxième niveau et l'évaluation directe. Les procédures d'évaluation directe pour chaque échec de stabilité sont développées avec la technologie de pointe la plus avancée disponible soit par analyse numérique, soit par travail expérimental pour une analyse quantitative. Dans cette thèse, on présente une implémentation des niveaux 1 et 2 du SGISC dans le solveur hydrostatique, une approche expérimentale pour le navire en détresse dans une tempête et des simulations RANS du même critère. En conclusion, il est possible de mettre en oeuvre les critères de stabilité du navire intact de deuxième génération dans le code de stabilité GHS ©, un code couramment utilisé par les industriels dans le domaine. Cinq navires ont été considérés pour vérifier cette mise en oeuvre. Une méthode expérimentale utilisant une grande soufflerie et une méthode de calcul CFD simplifiée ont été appliquées sur deux modèles. Dans les deux cas, les résultats montrent que l'angle de roulis maximal atteint par les deux navires étudiés est inférieur à celui donné par le calcul réglementaire. La méthode expérimentale est certainement plus proche de la réalité et le calcul CFD reste conservateur sans être aussi contraignant que la réglementation. En conclusion les méthodes expérimentale et numérique développées et utilisées dans ce travail de thèse peuvent être proposées pour l’évaluation directe du critère. / The Sub-Committee of Ship Design and Construction of International Maritime Organisation (IMO) has undertaken the development of Second Generation Intact Stability Criteria (SGISC). The GISC is an additional rule that complement present rules. Five failure modes will be address in SGISC are excessive roll in dead ship condition, pure loss of stability, broaching, parametric roll, and excessive acceleration. Moreover, these criteria are structured in three levels namely, first level, second level and direct assessment. Direct assessment procedures for every stability failure are developed with the most advanced state-of-the art technology available either by numerical analysis or experimental work for quantitative analysis. In this thesis, implementations of Level 1 and Level 2 of the SGISC in the hydrostatic solver, experimental approached for dead ship condition and RANS simulation are presented.In conclusion, it was possible to implement the stability criteria of the intact second-generation vessel in the GHS © code of stability, a code commonly used by industrialists in the field. Five vessels were considered to verify this implementation. An experimental wind tunnel method and a simplified CFD calculation method were used on two different models. In both cases, the results show that the maximum roll angle reached by the two vessels studied is lower than the one given by the regulatory calculation. The experimental method is certainly closer to reality and the calculation CFD remains conservative without being as binding as the regulation.Therefore, the two approaches, numerical and experimental can be proposed to be used for Direct Assessment of the criterion.
197

Etude et implémentation des critères de seconde génération dans un code de stabilité / Analysis and implementation of second generation criteria in a stability computer code

Grinnaert, François 19 January 2017 (has links)
Les critères de stabilité à l’état intact de seconde génération sont en cours de finalisation par l’Organisation Maritime Internationale. Ils doivent compléter les critères actuels en apportant une sécurité accrue dans les vagues. Ils sont organisés en cinq modes de défaillance et trois niveaux d’évaluation dans chaque mode de défaillance. Le premier niveau est basé sur une approche déterministe simplifiée des phénomènes et assure des marges de sécurité importantes. Le second niveau requiert des calculs plus complexes basés sur des considérations hydrostatiques dans les vagues. Il est supposé assurer des marges de sécurité réduites. Le troisième niveau, actuellement en cours de développement, devrait consister en des simulations numériques du comportement du navire sur des états de mer réels réalisés par des instituts spécialisés. Les deux premiers niveaux des modes de défaillance perte pure de stabilité et roulis paramétrique ont été implémentés dans un code de stabilité. Les courbes de KGmax associées à ces critères sont calculées pour une sélection de navires civils et militaires de différents types ayant des comportements connus ou supposés différents vis-à-vis de ces modes de défaillance. Les exigences et la pertinence des critères sont analysées. La seconde vérification du critère de niveau deux en roulis paramétrique est étudiée en détail. Une méthode simplifiée de calcul de l’angle maximum de roulis paramétrique supposant un GZ linéaire est proposée et implémentée dans le critère correspondant. / The second generation intact stability criteria are currently under finalization by the International Maritime Organization. They are intended to improve the current intact stability rules by adding safety in waves. They are structured in five failure modes and three levels of assessment in each failure mode. The first level is based on a simplified deterministic approach of the phenomena and ensures high safety margins. The second level requires more complex computations based on hydrostatic considerations with regard to static waves and is expected to provide reduced safety margins. The third level, currently under development, would consist of numerical simulations of the ship’s behavior in real sea states performed by specialized institutes. Level-one and level-two criteria of both pure loss of stability and parametric roll failure modes have been implemented in a stability code. The KGmax curves associated with these future criteria are computed for a selection of different ships of different types, both civilian and military, expected or known to have different behaviors with regard to the considered failure modes. The requirement and the relevance of the criteria are analyzed. The second check of parametric roll level-two criterion is thoroughly analyzed. A simplified method providing the maximum parametric roll angle assuming a linear GZ is developed and implemented in the corresponding criterion.
198

Exploring hybridity in the 21st century : the working lives of South Asian ethnic minorities from a British born generation in Bradford

Rifet, Saima January 2015 (has links)
This thesis explores the working lives of British Born South Asian Ethnic Minorities (BB SAEMs), critiquing the homogenous identities ascribed to them in previous research. Its methodology is life-story interviews analysed using Nvivo. This identified four hybrid categories emerging from two cultures. I fitted myself neatly into just one. However the reflexive analysis required in good qualitative research led me to realise that I fitted into not one, but all four categories, and into others not yet recognised. At this point, my thesis had to take a new turn. An auto-ethnographic, moment-by-moment study led to an ‘unhybrid categorisation of hybridities’ acknowledging ‘fuzziness and mélange, cut ‘n’ mix, and criss and crossover’ where identity is a complex-mix, always in flux. I conclude not only with this new theory of identity formation in the working lives of BB SAEMs, but also by arguing that by imposing the requirement to categorise, research methods lead to over-simplification and misunderstanding.
199

Druhá generace biopaliv v reálném světě / The second generation of biofuels in the real world

Skalický, Michal January 2009 (has links)
The diploma thesis deals with the problematics of biofuels as a renewable source of energy in transportation, which has recently gotten under social spotlight. The theoretical part is focused on an explanation of basic terminology, historical development and especially reasons for the need to replace current fosil fuels with respect to an increasing volume of CO2 and shortening oil reserves. The practical part compares characteristics, use, pros and cons of the biofuels of the first and second generation and tries to estimate benefits of the biofuels of the second generation in both economic and environmental area.
200

En studie över etnisk boendesegregation i Sverige : Med fokus på andra generationens invandrare

Soyal, Bejna Dilsen January 2016 (has links)
The study is a qualitative study that aims to examine how foreign-born parents affect second-generation immigrants choice of form of housing and residential areas and what differences there are between Swedish native-born and foreign-born parents. The study also examines how ethnicity affects young adults' choice of housing and residential area and the importance of second-generation immigrants attitudes towards segregated areas in the future have. The study focuses on the residential neighbourhoods of Sätra located in Gävle and Vivalla located in Örebro. Both neighbourhoods are million program areas but in different ways. The data collection consisted of ten people, five women and five men. The method asked specific questions and then interviewees spoke about themselves and how they perceive housing segregation. The selection has been made strategically thus the people that have been interviewed are born in Sweden and have parents that are born abroad. Also all of the interviewed individuals live in segregated areas. There is a lot of prejudice in the media and the public about segregation and the vulnerability of segregated areas. The results shows five women and five men’s own experiences and thoughts about living in segregated residential areas, having foreign- born parents, how both have affected them and their views of ethnic segregation. / Undersökningen är en kvalitativ studie där intervjuer kommer göras för att jag somforskare ska kunna befinna mig i den sociala miljön som analyseras. Studien syftar tillatt granska hur utlandsfödda föräldrar påverkar andra generationens invandrares val avbostadsform och bostadsområde samt vilka skillnader det finns mellan inlandsfödda ochutlandsfödda föräldrar. Samt hur etnicitet påverkar unga vuxnas val av bostadsform ochbostadsområde och vilken betydelse andra generationens invandrares inställning tillboendesegregerade områden i framtiden har. För att utföra arbetet har en fallstudieanvänts. Anledningen till att en fallstudie har använts är för att arbetet ska utföras underen tidsbegränsad period. I studien ligger fokus på bostadsområdena Sätra och Vivalla,det dessa två områden har gemensamt är att de är segregerade på olika sätt och ärmiljonprogramsområden. Datainsamlingen bestod av tio personer, fem kvinnor och femmän. I studien tas intervjupersonernas erfarenheter, tankar och upplevelser med ochmetoden går ut på att ställa bestämd frågor och sedan har intervjupersonerna fått pratautifrån sig själva och hur de själva upplever ämnet. Urvalet är strategiskt, detintervjupersonerna har gemensamt är att de själva är födda i Sverige och harutlandsfödda föräldrar från olika länder samt bor i segregerade områden. Detförekommer mycket fördomar av media och människor utifrån på grund avsegregationen och utsattheten som råder i områdena. Resultatet visar fem kvinnor ochfem mäns egna erfarenheter, upplevelser och tankar av att bo i bostadsområdena och attha utlandsfödda föräldrar, hur det har påverkat dem och hur de ser på den etniskaboendesegregationen.

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