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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.
61

Debussys Streichquartett – ein Werk gegen die Akademie?

Winkler, Andreas J. 22 October 2023 (has links)
No description available.
62

The Knee Response during Squats with Heels Up and Down

Metelues, Francis Gabriel 01 August 2014 (has links)
No description available.
63

A geografia econômica do setor agroalimentar brasileiro: investimentos, recursos ociosos e dinâmica cíclica (1990 - 2007) / The economic geography in Brazilian food industry: investments, idle resources and cyclical dynamics (1990 - 2007)

Medeiros, Marlon Clovis 31 August 2009 (has links)
A presente tese analisa o desenvolvimento do setor agroalimentar brasileiro, no período pós-1990, e suas relações com as oscilações da economia brasileira, com sua inserção internacional e com a política agrícola. O papel dos investimentos, da demanda e dos recursos ociosos ocupa espaço central na análise. A hipótese central é que a dinâmica do setor agroalimentar brasileiro, na década de 1990 e seguinte, foi marcada mais pelo amadurecimento dos investimentos realizados nas décadas de 1970 e 80, do que pela dinâmica da abertura e desmonte da ação do Estado da década de 1990. Baseado na teoria da dinâmica cíclica com formação de recursos ociosos de Ignácio Rangel e com apoio de ampla análise de dados argumentou-se que: 1- o crescimento do setor agroalimentar na década de 1990, e das exportações agrícolas após 1999, foram possíveis pelos investimentos e pela política de desenvolvimento do setor das décadas de 1970 e 80. Os investimentos no setor agroalimentar possuem uma dinâmica cíclica que respondeu a partir da década de 1990 reativamente ao crescimento, e que retornam após 1999 com recursos oficiais e a partir de 2003 com a elevação dos preços internacionais de commodities agrícolas. 2- a trajetória dos sub-setores do setor agroalimentar foi heterogênea, em conseqüência da mesma política macroeconômica. Logo, a diferença dos impactos causados relacionou-se diretamente a trajetória de cada sub-setor no período anterior à abertura em termos de investimentos, de nível tecnológico e em especial quanto as perspectivas de crescimento ou estagnação da demanda. 3- As oscilações da conjuntura, da política macroeconômica e das políticas setoriais são fundamentais. O setor é sensível a distribuição de renda, às taxas de crescimento do PIB e ao aumento do desemprego. Além disso, o setor agroalimentar apresentou um papel político central: na década de 1980, como elemento para o controle da inflação, recebeu incentivos e proteção; na década de 1990, as exportações são liberadas mas recorre-se às importações para baixar os preços internos. Após 1999, o setor passa a ocupar novamente o lugar de auxiliar na obtenção de divisas, de redução do déficit comercial e retomada do crescimento do PIB (como no início da década de 1980). Com isso, os interesses do setor se reforçam (incluindo seus representantes no legislativo e no executivo) e novas políticas setoriais de incentivo começam a surgir. 4- A dinâmica regional da agricultura é outro elemento central para se compreender os movimentos mais amplos do setor. A ociosidade de terras e de instalações industriais (devido as grandes distâncias entre as áreas produtoras de matérias-primas e a indústria e também devido aos impostos interestaduais) possui um componente territorial que influencia em toda a dinâmica do setor agroalimentar. As diferentes condições de solo, relevo e clima influenciam na produtividade e na escolha das técnicas utilizadas, o que gera grande diferenciação regional no Brasil. / This thesis analyzes the development of the Brazilian food sector in the post-1990, and its relations with the fluctuations of the Brazilian economy, with its international integration and agricultural policy. The investments, demand and idle resources has an important role. The central hypothesis is that the dynamics of the Brazilian food industry in the 1990s and after, was leaded by maturity of the investments in the 1970s and 80s. Based on the theory of cyclical dynamics with formation of idle resources by Ignacio Rangel and with broad support from data analysis, it was argued that: 1- the growth of food industry in the 1990s, and agricultural exports after 1999 were made possible by the investments and the development policy of the industry of the 1970s and 80s. Investment in food sector have a cyclical dynamic that responded from the 1990s reactively growth, and after returning in 1999 with governmental resources from 2003 to the rising international prices of agricultural commodities. 2- the trajectory of the sub-sectors of the food industry was heterogeneous, as a result of the macroeconomic policy. The difference of the impact caused is related directly to the trajectory of each sub-sector in the period before the opening, in terms of investments, technological level and specially on the prospects for growth or stagnation of demand. 3- Fluctuations in the economy, the macroeconomic policy and sectoral policies are crucial. The food sector is sensitive to distribution of income, the growth rates of GDP and increased unemployment. Moreover, the food sector had a central political role: in the 1980s, as an element for controlling inflation, its received subsidies and protection, in the 1990s, exports are released but it relies on imports to reduce domestic prices. After 1999, the food sector will again occupy the place of help in obtaining foreign currency, reducing the trade deficit and leading to growth of GDP (as in the early 1980\'s). With this, the interests of the sector is strengthening (including their representatives in the legislative and the executive) and new policies to encourage food sector begin to emerge. 4- The regional dynamics of agriculture is another key element to understanding the movements of the food sector. The idleness of land and industrial plants (due to the large distances between the areas producing raw materials and industry and also due to tax interstate) has a territorial component that influences the dynamic in the food sector. The different soil conditions, topography and climate influence the productivity and the choice of techniques, which generates large regional differences in Brazil.
64

Modelo matemático para avaliação hidrodinâmica em reatores tubulares operando em regime não-permanente / Mathematical model for hydrodynamic evaluation of pipe reactors with diffusion operated in non-steady flow

Salgado, Monique Toledo 27 June 2008 (has links)
No meio científico são bastante utilizados os modelos matemáticos para avaliar as características hidrodinâmicas de reatores, porém a literatura é pobre em informações relativas à aplicação do equacionamento matemático em regime não-permanente. Neste trabalho foi aplicado um modelo matemático simulando a hidrodinâmica de reatores tubulares com dispersão para avaliar o efeito da variação de vazão afluente sobre os parâmetros hidrodinâmicos. As simulações foram efetuadas considerando vazão e volume constantes, vazão e volume variáveis e vazão variável e volume constante. Foi investigada a influência de dois tipos de ensaios estímulo-resposta, pulso e degrau, para aplicação de modelos matemáticos e determinação das curvas de distribuição do tempo de residência (DTR) experimentais. Teoricamente ambos devem fornecer os mesmos resultados embora o ensaio em pulso costume apresentar maior sensibilidade experimental. Conforme esperado, ambos os ensaios apresentaram os mesmos resultados finais. Também foram avaliados os traçadores empregados nos dois tipos de ensaios estímulo-resposta, pulso e degrau. Foram empregados três traçadores diferentes - verde de bromocresol, azul de bromofenol e eosina Y que proporcionaram curvas com diferentes características. Como ferramenta auxiliar da modelação foram estudas a determinação das curvas DTR experimentais com auxílio de duas técnicas distintas. Para calibrar o modelo matemático proposto foram utilizados dados de reatores em escala de bancada com diferentes configurações submetidas a variações de vazões afluentes. Os dados de um reator UASB em escala piloto - submetido a variações cíclicas de vazão afluente de 40 e 60% - foram empregados para calibrar e verificar o modelo matemático proposto. Os resultados encontrados com o modelo matemático proposto nesta pesquisa demonstraram que a variação de vazão afluente não deve ser negligenciada. O modelo utilizado representou adequadamente o reator UASB. Seus resultados, quando comparados aos modelos matemáticos que não consideram a variação de vazão, mostraram que para flutuações de vazão elevadas, vazões com valores até 60% maiores do que a vazão média, os valores dos coeficientes de difusão diferem significativamente em função das hipóteses empregadas no desenvolvimento do modelo matemático. / Mathematical models for hydrodynamic characteristics evaluation of reactors are commonly used however there is a lack of information in the literature concerning the application of mathematical modeling for non-steady state flow. In this thesis, it is presented a non-steady mathematical model to simulate the hydrodynamic behavior of pipe flow reactors with diffusion in order to evaluate the effect of the variation of the influent flowrate in the hydrodynamic parameters. The simulations were performed considering constant flowrate and volume, variable flowrate and volume and, variable flowrate and constant volume. It was investigated the influence of two types of stimulus-response assays, pulse and step function, on the application of mathematical models and the determination of the experimental retention time distribution curves. Theoretically, both tests should provide the same results although the pulse stimulus assay usually presents higher experimental sensitivity. As it was expected, both tests presented the same final results. The tested tracers were also evaluated in relation to the pulse and step stimulus-response tests. Three tracers were tested (bromocresol green, bromophenol blue and eosin Y) and it was shown that they provided different curves. It was studied the construction of the experimental retention time distribution curves using two procedures as an auxiliary tool for modeling. The proposed mathematical model was calibrated with data of bench scale reactors submitted to different cyclical variations of flowrates. Moreover, data of UASB reactor in pilot scale - submitted to 40 and 60% of cyclical variations of flowrates were utilized to calibrate and verify the obtained mathematical model. The results found with the mathematical model proposed in this research showed that the variations in influent flow rate can not be neglected. The model adequately represented a pilot scale UASB reactor. The results showed that the diffusion coefficients differ significantly for high flowrate fluctuations, when compared to other mathematical models that do not incorporate variable flowrate, depending upon the hypothesis used to derive the model.
65

A rela??o c?clica entre informa??o, pessoas, conhecimento e inova??o : uma an?lise cr?tica / The cyclical relation among information, people, knowledge and innovation : a critical analysis

Oliveira, Leonardo Cassa de 27 October 2004 (has links)
Made available in DSpace on 2016-04-04T18:36:41Z (GMT). No. of bitstreams: 1 Leonardo Cassa de Oliveira.pdf: 1112623 bytes, checksum: 3380a5d2c962baef4c467adc48cabcf2 (MD5) Previous issue date: 2004-10-27 / This present dissertation proposal was to demonstrate, theoretically, that the innovations result from a Cyclical Relation, and establish a critical reflection comparing the presuppositions and practices to the generation of innovations and the organization s present thought, which priories productivity gains with costs reduction, specially with people. It s an exploratory research based in bibliographical revision. The critical analysis of notorious theoreticians permitted to verify that innovation determines the existent economic order and, consequently, the direction that the organizations should follow in the search for extraordinary gains or simply survival. Innovation results from a Cyclical Relation that involves information, people, and consequent creation, sharing and knowledge combination. Empirical studies analysis demonstrated that management practices oriented to organizational learning and knowledge creation provide a great extent in the generation of innovations and announce an organization that prioritizes the human interaction and time dedication to the learning process. On the other hand, the present productivity thought potencializes automated organizations with the least of people interacting. The final perspective indicates that the reflection about this dilemma is not a simple, direct and immediate answer to the way that should be followed, but contributes to visualize that it s necessary to change the present thought. / O presente trabalho teve por objetivo demonstrar teoricamente que as inova??es decorrem de uma Rela??o C?clica e, com isso, estabelecer uma reflex?o cr?tica comparando os pressupostos e pr?ticas para a gera??o de inova??es e o pensamento vigente das organiza??es, o qual prioriza ganhos de produtividade com redu??o de custos, especialmente com pessoas. Trata-se de um estudo de natureza explorat?ria baseado em pesquisa bibliogr?fica. A an?lise cr?tica de te?ricos reconhecidos permitiu verificar que a inova??o determina a ordem econ?mica existente e, por conseq??ncia, a dire??o que as organiza??es devem seguir na busca por ganhos extraordin?rios ou simplesmente sobreviv?ncia. A inova??o decorre de uma Rela??o C?clica que envolve informa??o, pessoas e, conseq?ente cria??o, compartilhamento e combina??o de conhecimentos. Estudos emp?ricos analisados demonstraram que pr?ticas gerenciais orientadas para a aprendizagem organizacional e cria??o de conhecimentos proporcionam maior amplitude na gera??o de inova??es e anunciam uma organiza??o que prioriza a intera??o humana e a dedica??o de tempo ao aprendizado. Por outro lado, o pensamento vigente de produtividade potencializa organiza??es automatizadas com o m?nimo de pessoas interagindo. A perspectiva final aponta que a reflex?o sobre esse dilema n?o se traduz numa resposta simples, direta e imediata para o caminho que deve ser seguido, mas contribui para visualizar que ? necess?rio mudar o pensamento vigente.
66

Analyse du cycle économique. Datation et prévision / Business Cycle Analysis. Dating and Forecasting

Majetti, Reynald 07 November 2013 (has links)
La « Grande Récession » de 2008-2009 ou encore l'aggravation de la crise des dettes souveraines et de la dette publique dans la zone euro à l'été 2011, constituent de récents événements qui ont cristallisé les enjeux de l'analyse conjoncturelle, ceux relatifs notamment à la datation et à la prévision des inflexions cycliques de l'activité réelle. L'objet de cette thèse s'inscrit fondamentalement au sein de ces deux approches complémentaires du cycle économique.Le chapitre 1 dresse un portrait du cycle autour de trois conceptions distinctes de ses points de retournement : le cycle classique, le cycle de croissance et le cycle d'accélération. Nous discutons également de sa mesure eu égard aux diverses représentations possibles de l'activité agrégée d'un pays, ainsi qu'aux deux traditions existantes dans lesquelles s'inscrivent les modèles de datation. Nous mettons par ailleurs en lumière l'influence grandissante de l'environnement financier sur la dynamique cyclique des économies. Le chapitre 2 nous amène à développer deux algorithmes non-paramétriques dans le but de repérer les inflexions propres à chacun des cycles auparavant conceptualisés, mais aussipour en mesurer leurs principales caractéristiques. Le premier (resp. le second) algorithme repose sur une représentation univariée (resp. multivariée) de l'activité économique globale ; in fine, nous les appliquons aux données de la conjoncture française entre 1970 et 2010. Le chapitre 3 tire parti de nos résultats en matière de datation conjoncturelle afin de prévoir les récessions françaises depuis 1974. Au moyen de modèles probits, nous illustrons le rôle de variables financières et monétaires en tant qu'indicateurs avancés des fluctuations du cycle des affaires français. Nous montrons de plus que nos modèles prédictifs assurent uneparfaite détection des récessions pour un horizon égal à deux trimestres.Le chapitre 4 prolonge l'ensemble de l'analyse à plusieurs États membres de la zoneeuro, ces derniers étant observés depuis 1979. Nous construisons d'abord une chronologie de leurs cycles classiques respectifs puis, nous proposons un examen de leurs caractéristiques moyennes et de leur degré de synchronisation. Enfin, en s'appuyant sur des indicateurs financiers et monétaires dans le cadre d'un probit dynamique à effets fixes, nous parvenons à anticiper - jusqu'à un horizon de deux trimestres - les épisodes récessifs survenus dans les économies considérées. / The « Great Recession » of 2008-2009 and the sovereign and public debt crises which strengthened in the euro area in the summer of 2011 are recent events that have crystallized the challenges facing economic analysis, especially those related to dating and predicting cyclical inflections of real activity. The purpose of this thesis is to study these two complementary approaches to the economic cycle. Chapter 1 provides a portrait of the cycle using three distinct conceptions of its turning points: the classical cycle, the growth cycle and the acceleration cycle. We also discuss the measurement of the cycle with respect to various possible representations of aggregate activity of a country, as well as to two existing traditions which encompass dating models. Moreover, we highlight the growing influence of the financial environment over business cycle fluctuations.In chapter 2, we develop two non-parametric algorithms in order to identify theinflections that are particular to each of the previously conceptualized cycles, but also to measure their main characteristics. The first algorithm is based on a univariate representation of overall economic activity, the second on its ultivariate representation; ultimately, we apply the algorithms to the data of the French economy between 1970 and 2010. Chapter 3 builds on our results for cyclical dating to predict French recessions since 1974. Using probit models, we illustrate the role of monetary and financial variables as leading indicators of French business cycle fluctuations. In addition, we show that our models accurately detect recessions for a forecasting lag of two-quarters. Chapter 4 extends the entire analysis to several member states of the euro zone, with observations beginning in 1979. We first construct a chronology of their classical cycles, and then we propose an analysis of their main characteristics and their degree of synchronization.Finally, based on financial and monetary indicators in the context of a dynamic probit with fixed effects, we can anticipate the recessionary episodes which occurred in these economies with a horizon of two quarters.
67

Zdeněk Fibich: Nálady, dojmy a upomínky / Zdeněk Fibich: Moods, Impressions, and Souvenirs

Špilauer, Jiří January 2018 (has links)
The dissertation deals with a complete cycle of piano pieces by Zdeněk Fibich called The Moods, Impressions and Reminiscences. The cycle has been largely presented in the literature as a `composer's love diary`, used to search for identical motifs across the composer's late work and understood in the context of programme music. The aim of the dissertation is to evaluate objectively this present majority view and to put a new view on it, to inform about the circumstances of the comprehensive complete edition of The Moods, Impressions and Reminiscences, to analyse the ensemble as a set of lyrical piano pieces with their specific purely musical features and to place the Fibich cycle into the context of the lyrical piano piece of the late 19th century. The work focuses mainly on musical- structural analysis based on grasping the form of compositions with the predominant way of thematic-motivational construction, observation and comparison of tonal fitting, dimension, prescribed times and searching for motivational, cyclic and other possible links. The results of the work enable us to view The Moods, Impressions and Reminiscences as a unique cycle of lyrical piano pieces from the end of the 19th century with their typical characteristics and key features of the musical kind and also show the unique...
68

A geografia econômica do setor agroalimentar brasileiro: investimentos, recursos ociosos e dinâmica cíclica (1990 - 2007) / The economic geography in Brazilian food industry: investments, idle resources and cyclical dynamics (1990 - 2007)

Marlon Clovis Medeiros 31 August 2009 (has links)
A presente tese analisa o desenvolvimento do setor agroalimentar brasileiro, no período pós-1990, e suas relações com as oscilações da economia brasileira, com sua inserção internacional e com a política agrícola. O papel dos investimentos, da demanda e dos recursos ociosos ocupa espaço central na análise. A hipótese central é que a dinâmica do setor agroalimentar brasileiro, na década de 1990 e seguinte, foi marcada mais pelo amadurecimento dos investimentos realizados nas décadas de 1970 e 80, do que pela dinâmica da abertura e desmonte da ação do Estado da década de 1990. Baseado na teoria da dinâmica cíclica com formação de recursos ociosos de Ignácio Rangel e com apoio de ampla análise de dados argumentou-se que: 1- o crescimento do setor agroalimentar na década de 1990, e das exportações agrícolas após 1999, foram possíveis pelos investimentos e pela política de desenvolvimento do setor das décadas de 1970 e 80. Os investimentos no setor agroalimentar possuem uma dinâmica cíclica que respondeu a partir da década de 1990 reativamente ao crescimento, e que retornam após 1999 com recursos oficiais e a partir de 2003 com a elevação dos preços internacionais de commodities agrícolas. 2- a trajetória dos sub-setores do setor agroalimentar foi heterogênea, em conseqüência da mesma política macroeconômica. Logo, a diferença dos impactos causados relacionou-se diretamente a trajetória de cada sub-setor no período anterior à abertura em termos de investimentos, de nível tecnológico e em especial quanto as perspectivas de crescimento ou estagnação da demanda. 3- As oscilações da conjuntura, da política macroeconômica e das políticas setoriais são fundamentais. O setor é sensível a distribuição de renda, às taxas de crescimento do PIB e ao aumento do desemprego. Além disso, o setor agroalimentar apresentou um papel político central: na década de 1980, como elemento para o controle da inflação, recebeu incentivos e proteção; na década de 1990, as exportações são liberadas mas recorre-se às importações para baixar os preços internos. Após 1999, o setor passa a ocupar novamente o lugar de auxiliar na obtenção de divisas, de redução do déficit comercial e retomada do crescimento do PIB (como no início da década de 1980). Com isso, os interesses do setor se reforçam (incluindo seus representantes no legislativo e no executivo) e novas políticas setoriais de incentivo começam a surgir. 4- A dinâmica regional da agricultura é outro elemento central para se compreender os movimentos mais amplos do setor. A ociosidade de terras e de instalações industriais (devido as grandes distâncias entre as áreas produtoras de matérias-primas e a indústria e também devido aos impostos interestaduais) possui um componente territorial que influencia em toda a dinâmica do setor agroalimentar. As diferentes condições de solo, relevo e clima influenciam na produtividade e na escolha das técnicas utilizadas, o que gera grande diferenciação regional no Brasil. / This thesis analyzes the development of the Brazilian food sector in the post-1990, and its relations with the fluctuations of the Brazilian economy, with its international integration and agricultural policy. The investments, demand and idle resources has an important role. The central hypothesis is that the dynamics of the Brazilian food industry in the 1990s and after, was leaded by maturity of the investments in the 1970s and 80s. Based on the theory of cyclical dynamics with formation of idle resources by Ignacio Rangel and with broad support from data analysis, it was argued that: 1- the growth of food industry in the 1990s, and agricultural exports after 1999 were made possible by the investments and the development policy of the industry of the 1970s and 80s. Investment in food sector have a cyclical dynamic that responded from the 1990s reactively growth, and after returning in 1999 with governmental resources from 2003 to the rising international prices of agricultural commodities. 2- the trajectory of the sub-sectors of the food industry was heterogeneous, as a result of the macroeconomic policy. The difference of the impact caused is related directly to the trajectory of each sub-sector in the period before the opening, in terms of investments, technological level and specially on the prospects for growth or stagnation of demand. 3- Fluctuations in the economy, the macroeconomic policy and sectoral policies are crucial. The food sector is sensitive to distribution of income, the growth rates of GDP and increased unemployment. Moreover, the food sector had a central political role: in the 1980s, as an element for controlling inflation, its received subsidies and protection, in the 1990s, exports are released but it relies on imports to reduce domestic prices. After 1999, the food sector will again occupy the place of help in obtaining foreign currency, reducing the trade deficit and leading to growth of GDP (as in the early 1980\'s). With this, the interests of the sector is strengthening (including their representatives in the legislative and the executive) and new policies to encourage food sector begin to emerge. 4- The regional dynamics of agriculture is another key element to understanding the movements of the food sector. The idleness of land and industrial plants (due to the large distances between the areas producing raw materials and industry and also due to tax interstate) has a territorial component that influences the dynamic in the food sector. The different soil conditions, topography and climate influence the productivity and the choice of techniques, which generates large regional differences in Brazil.
69

Modelo matemático para avaliação hidrodinâmica em reatores tubulares operando em regime não-permanente / Mathematical model for hydrodynamic evaluation of pipe reactors with diffusion operated in non-steady flow

Monique Toledo Salgado 27 June 2008 (has links)
No meio científico são bastante utilizados os modelos matemáticos para avaliar as características hidrodinâmicas de reatores, porém a literatura é pobre em informações relativas à aplicação do equacionamento matemático em regime não-permanente. Neste trabalho foi aplicado um modelo matemático simulando a hidrodinâmica de reatores tubulares com dispersão para avaliar o efeito da variação de vazão afluente sobre os parâmetros hidrodinâmicos. As simulações foram efetuadas considerando vazão e volume constantes, vazão e volume variáveis e vazão variável e volume constante. Foi investigada a influência de dois tipos de ensaios estímulo-resposta, pulso e degrau, para aplicação de modelos matemáticos e determinação das curvas de distribuição do tempo de residência (DTR) experimentais. Teoricamente ambos devem fornecer os mesmos resultados embora o ensaio em pulso costume apresentar maior sensibilidade experimental. Conforme esperado, ambos os ensaios apresentaram os mesmos resultados finais. Também foram avaliados os traçadores empregados nos dois tipos de ensaios estímulo-resposta, pulso e degrau. Foram empregados três traçadores diferentes - verde de bromocresol, azul de bromofenol e eosina Y que proporcionaram curvas com diferentes características. Como ferramenta auxiliar da modelação foram estudas a determinação das curvas DTR experimentais com auxílio de duas técnicas distintas. Para calibrar o modelo matemático proposto foram utilizados dados de reatores em escala de bancada com diferentes configurações submetidas a variações de vazões afluentes. Os dados de um reator UASB em escala piloto - submetido a variações cíclicas de vazão afluente de 40 e 60% - foram empregados para calibrar e verificar o modelo matemático proposto. Os resultados encontrados com o modelo matemático proposto nesta pesquisa demonstraram que a variação de vazão afluente não deve ser negligenciada. O modelo utilizado representou adequadamente o reator UASB. Seus resultados, quando comparados aos modelos matemáticos que não consideram a variação de vazão, mostraram que para flutuações de vazão elevadas, vazões com valores até 60% maiores do que a vazão média, os valores dos coeficientes de difusão diferem significativamente em função das hipóteses empregadas no desenvolvimento do modelo matemático. / Mathematical models for hydrodynamic characteristics evaluation of reactors are commonly used however there is a lack of information in the literature concerning the application of mathematical modeling for non-steady state flow. In this thesis, it is presented a non-steady mathematical model to simulate the hydrodynamic behavior of pipe flow reactors with diffusion in order to evaluate the effect of the variation of the influent flowrate in the hydrodynamic parameters. The simulations were performed considering constant flowrate and volume, variable flowrate and volume and, variable flowrate and constant volume. It was investigated the influence of two types of stimulus-response assays, pulse and step function, on the application of mathematical models and the determination of the experimental retention time distribution curves. Theoretically, both tests should provide the same results although the pulse stimulus assay usually presents higher experimental sensitivity. As it was expected, both tests presented the same final results. The tested tracers were also evaluated in relation to the pulse and step stimulus-response tests. Three tracers were tested (bromocresol green, bromophenol blue and eosin Y) and it was shown that they provided different curves. It was studied the construction of the experimental retention time distribution curves using two procedures as an auxiliary tool for modeling. The proposed mathematical model was calibrated with data of bench scale reactors submitted to different cyclical variations of flowrates. Moreover, data of UASB reactor in pilot scale - submitted to 40 and 60% of cyclical variations of flowrates were utilized to calibrate and verify the obtained mathematical model. The results found with the mathematical model proposed in this research showed that the variations in influent flow rate can not be neglected. The model adequately represented a pilot scale UASB reactor. The results showed that the diffusion coefficients differ significantly for high flowrate fluctuations, when compared to other mathematical models that do not incorporate variable flowrate, depending upon the hypothesis used to derive the model.
70

Vers une autonomie en apprentissage selon le chemin du milieu : le cas des étudiants de français à l’Université Nationale de Hanoï / Towards autonomy in learning according to the middle way : the case of students of French at the National University of Hanoi

Do, Thanh Thuy 14 October 2016 (has links)
Le présent travail vise à approfondir la problématique de l’autonomie en apprentissage, considéré comme une exigence incontournable de l’éducation. Il aborde le sujet étudié en tenant compte de la dimension culturelle et part du constat d’une difficulté d’application des modèles occidentaux dans le contexte de l’apprentissage du français langue étrangère au Vietnam. Il s’appuie sur une recherche abductive utilisant la méthode d’analyse par théorisation ancrée qui favorise des allers-retours successifs entre le travail empirique et les théories mobilisées. Un corpus riche et complexe a été recueilli au moyen du filmage, des entretiens, de l’écriture des journaux de bord des quatre étudiants suivis, des échanges par courriels et de la prise de notes. Dégager la complexité du concept d’autonomie a exigé l’exploration des notions de stratégie et de compétence ainsi que l’identification des difficultés lors des apprentissages. Ce travail a permis de révéler que l’émotion joue un rôle intermédiaire dans la relation interdépendante des composantes de l’apprentissage. Cette relation est fondée sur des causalités à la fois linéaire et cyclique. En montrant les types d’entraves dont l’acteur-apprenant doit se délivrer pour devenir autonome, l’étude affirme la nécessité pour l’apprenant de garder l’équilibre entre des modes analytique et synthétique. Soutenir l’apprenant dans son apprentissage implique que le tuteur l’accompagne vers cet équilibre et s’efforce lui-même aussi de le maintenir durant le processus de soutien. / The aim of this thesis is to analyse in depth the question of learner autonomy, considered to be a fundamental requirement in the educational field. Adopting a cultural perspective, the study acknowledges first of all the difficulty in applying western models to the context of learning French as a foreign language in Vietnam. It adopts an abductive research method based on a grounded theory approach entailing successive interplay between empirical work and theory. A rich and complex corpus has been collected through filming, interviews, the log-books of the four students observed, the exchange of emails and note-taking. In order to elucidate the complexity of the concept of autonomy it was necessary to explore the notions of strategy and competence and to identify learning difficulties. The study reveals notably that emotion plays an intermediary role in the interdependent relationship between the different learning components. This relationship is based upon both linear and cyclical causality. By showing the different obstacles the actor-learner must overcome in order to be autonomous, the study affirms the necessity to keep a balance between analytic and synthetic modes of thinking. Scaffolding the leaner’s development requires the tutor to accompany him/her towards this balance and to endeavour to maintain the same balance during the scaffolding process.

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