Há pouca informação sobre o agronegócio sustentável para biocombustíveis elaborados a partir de oleaginosas florestais perenes, num contexto de sóciobiodiversidade. Na presente pesquisa, foi proposto e aplicado um framework para analisar a emergência, evolução e consolidação de uma filière do biodiesel a partir da macaúba, uma oleaginosa florestal perene, orientada pelo desenvolvimento sustentável. Para isso, utilizou-se a combinação de três abordagens e instrumentos, resumidos a seguir: O primeiro é o metaframework transdisciplinar de Munasinghe (2002), o Sustainomics. O segundo, constituído pela análise de filière, uma abordagem francesa, e suas diretrizes mesoanalíticas: tecnologias, estratégia e relações (MONTIGAUD, 1991). O terceiro, no âmbito da Economia Evolutiva, utilizou-se o framework Micro-Meso-Macro (DOPFER, FOSTER e POTTS, 2004). Essas abordagens e alguns de seus instrumentos foram ajustados entre si, por meio de suas dimensões e elementos integrativos, para proposição de um novo framework na presente pesquisa, intitulado “Cadeia Oleaginosa Florestal Perene Micro- Meso-Macro Transdisciplinar-Sustainomics”, concebido tanto para a identificação como a recomendação de prioridades presentes e futuras para a cadeia estudada. A presente pesquisa é exploratória e qualitativa, na qual foram coletados dados primários e secundários. Na coleta de dados primários, foram feitas entrevistas, registradas em vídeo. Dos 7 elos identificados na filière da macaúba, o estudo de caso abordou os sistemas de produção, adotados e prospectados, no Elo Agrícola e na Agroindústria, no período entre 2004 a 2009, no locus geográfico do município de Montes Claros/MG. Os resultados foram interpretados com base nos instrumentos Matriz de Impacto da Ação, Análise diagnóstica sistêmica da filière e em duas técnicas da Economia Evolutiva: a Trajetória Micro Como um Domínio Analítico e a Análise da Trajetória Meso Genérica. Identificou-se em primeiro lugar, que das 6 empresas que atuam diretamente na filière emergente, no Brasil, nenhuma explora exclusivamente biodiesel de macaúba. Em segundo, existe a possibilidade de um jogo do tipo ganha-ganha no caso analisado, possibilitando simultaneamente “a melhoria da vida das pessoas pobres e o combate ao problema das mudanças climáticas” (MUNASINGHE, 2002). Na analise dos resultados são apontados, a recomendação de substituições progressivas: 1) Do diesel fóssil por biocombustíveis, que tenham ciclo de vida, de fato, renovável; 2) Das matérias-primas de ciclo anual, com baixos rendimentos em biocombustíveis, provenientes de monocultivos, por policultivos de culturas perenes, da biodiversidade dos biomas, com foco na macaúba para o Cerrado; 3) Da monocultura da soja pelas matérias-primas para biocombustíveis oriundas dos recursos florestais naturais não madeiráveis, organizada em sistema de produção agroflorestas sucessionais, com inovação pelo uso nas áreas de Reservas Legais, sustentáveis na forma de campos de produção. 4) Da entropia do desmatamento, pela sintropia; 5) Do biodiesel pelo uso direto – SVO: desatrelar o processo tecnológico agroindustrial equivocado de transesterificação do óleo vegetal para retirada da glicerina do óleo; 6) Dos motores de ciclo diesel não adiabáticos, produzidos e utilizados no Brasil, por novas tecnologias disponíveis: operar com temperaturas mais altas para queimar, como biocombustível, também a glicerina, evitar a desnecessária geração de resíduos. Por fim, o framework de análise para culturas perenes oleaginosas sustentáveis (Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics) utilizado neste estudo de caso, pode ser aplicado para outras culturas similares, com o objetivo de evitar catástrofes bruscas, sem demora, eliminando atividades que ameacem superar o limiar de segurança e capacidade de carga dos ecossistemas da Terra, por meio do aumento de sua resiliência. / There is little information about the sustainable agribusiness for biofuels made from perennial oil forest of sociobiodiversity context. This research aimed to propose a framework and analyze the emergence, evolution and consolidation of a biodiesel filière from Macaúba, guided by sustainable development. For this, it proposes a new model by combinning tree approaches and instruments from the models sumarized as follow: The first tool model is the practical method of Munasinghe (2002): a transdisciplinary metaframework, the Sustainomics, that has evaluative techniques of unsustainable activities. The second is the Filière Method, composed by the following mesoanalitics guidelines: technology, strategy and relationships (MONTIGAUD, 1991). The third envolves levels of Evolutionary Economics, derivatives from the Framework Micro-Meso-Macro (DOPFER FOSTER and POTTS, 2004). These approaches and some instruments used from the models, fit together the dimensions and elements of integration, to propose the mentioned new model entitled as a neologism “Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics”, designed to identify and to recommend urgent priorities in the present and in the future, to the studied chain. This research is exploratory, qualitative, within collected primary and secondary data. Primary data was interviews with video recorded. From the seven rings of chain (Macaúba filière) that were identified, the study case addresses the production systems, some adopted and some prospected, in Agricultural and Agroindustry rings, between the period from 2004 to 2009, the geographical locus of the municipality of Montes Claros/MG. The results were analyzed based on the instruments, as follow: Action Impact Matrix, Diagnostic analysis of systemic filière, and two Evolutionary Economics techniques: Trajectory Micro as an Analytical Domain and Analysis of the Meso Generic Trajectory. It was identified, first, that: the six companies operating directly in emerging filière, none operates exclusively Macaw Palm’s biodiesel. The Second consideration refers that it is possible a win-win game, for the analysed case, making possible coexistence: “improving the lives of poor people and addressing the issue of climate change” (MUNASINGHE, 2002). The results pointed the recomendations of progressive replacement of: 1) The fossil diesel through biofuels, which have life cycle, in fact, renewed; 2) The raw materials of the annual cycle, with low yields of biofuels from monocultures, through polycultures of perennial crops, from biodiversity biomes, focusing on Macaw Palm, for Savannah. 3) the monoculture of soybeans for biofuels, through raw-material derived from Non-Timber Natural Forest resources, organized in successional agroforestry system of production, with innovation for use inthe areas of Legal Reserves, as sustainable production fields. 4) The entropy of deforestation, through the Syntropy; 5) From biodiesel through the direct use - SVO: unleash the technological process of wrong agroindustrial transesterification of vegetable oil to remove the glycerin from the oil; 6) From diesel cicle engines non-adiabatic, produced and used in Brazil through new available technologies: to operate at higher temperatures to burn, as biofuel, as well as glycerin, to avoid unnecessary waste generation. Summing up, the analysis model for perennial crops, oilseeds sustainable (Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics), used in this case study can be applied to other similar cultures, in order to prevent sudden disasters, without delay, eliminating activities that threaten to exceed the safety threshold and carrying capacity of Earth's ecosystems, by increasing its resilience.

Há pouca informação sobre o agronegócio sustentável para biocombustíveis elaborados a partir de oleaginosas florestais perenes, num contexto de sóciobiodiversidade. Na presente pesquisa, foi proposto e aplicado um framework para analisar a emergência, evolução e consolidação de uma filière do biodiesel a partir da macaúba, uma oleaginosa florestal perene, orientada pelo desenvolvimento sustentável. Para isso, utilizou-se a combinação de três abordagens e instrumentos, resumidos a seguir: O primeiro é o metaframework transdisciplinar de Munasinghe (2002), o Sustainomics. O segundo, constituído pela análise de filière, uma abordagem francesa, e suas diretrizes mesoanalíticas: tecnologias, estratégia e relações (MONTIGAUD, 1991). O terceiro, no âmbito da Economia Evolutiva, utilizou-se o framework Micro-Meso-Macro (DOPFER, FOSTER e POTTS, 2004). Essas abordagens e alguns de seus instrumentos foram ajustados entre si, por meio de suas dimensões e elementos integrativos, para proposição de um novo framework na presente pesquisa, intitulado “Cadeia Oleaginosa Florestal Perene Micro- Meso-Macro Transdisciplinar-Sustainomics”, concebido tanto para a identificação como a recomendação de prioridades presentes e futuras para a cadeia estudada. A presente pesquisa é exploratória e qualitativa, na qual foram coletados dados primários e secundários. Na coleta de dados primários, foram feitas entrevistas, registradas em vídeo. Dos 7 elos identificados na filière da macaúba, o estudo de caso abordou os sistemas de produção, adotados e prospectados, no Elo Agrícola e na Agroindústria, no período entre 2004 a 2009, no locus geográfico do município de Montes Claros/MG. Os resultados foram interpretados com base nos instrumentos Matriz de Impacto da Ação, Análise diagnóstica sistêmica da filière e em duas técnicas da Economia Evolutiva: a Trajetória Micro Como um Domínio Analítico e a Análise da Trajetória Meso Genérica. Identificou-se em primeiro lugar, que das 6 empresas que atuam diretamente na filière emergente, no Brasil, nenhuma explora exclusivamente biodiesel de macaúba. Em segundo, existe a possibilidade de um jogo do tipo ganha-ganha no caso analisado, possibilitando simultaneamente “a melhoria da vida das pessoas pobres e o combate ao problema das mudanças climáticas” (MUNASINGHE, 2002). Na analise dos resultados são apontados, a recomendação de substituições progressivas: 1) Do diesel fóssil por biocombustíveis, que tenham ciclo de vida, de fato, renovável; 2) Das matérias-primas de ciclo anual, com baixos rendimentos em biocombustíveis, provenientes de monocultivos, por policultivos de culturas perenes, da biodiversidade dos biomas, com foco na macaúba para o Cerrado; 3) Da monocultura da soja pelas matérias-primas para biocombustíveis oriundas dos recursos florestais naturais não madeiráveis, organizada em sistema de produção agroflorestas sucessionais, com inovação pelo uso nas áreas de Reservas Legais, sustentáveis na forma de campos de produção. 4) Da entropia do desmatamento, pela sintropia; 5) Do biodiesel pelo uso direto – SVO: desatrelar o processo tecnológico agroindustrial equivocado de transesterificação do óleo vegetal para retirada da glicerina do óleo; 6) Dos motores de ciclo diesel não adiabáticos, produzidos e utilizados no Brasil, por novas tecnologias disponíveis: operar com temperaturas mais altas para queimar, como biocombustível, também a glicerina, evitar a desnecessária geração de resíduos. Por fim, o framework de análise para culturas perenes oleaginosas sustentáveis (Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics) utilizado neste estudo de caso, pode ser aplicado para outras culturas similares, com o objetivo de evitar catástrofes bruscas, sem demora, eliminando atividades que ameacem superar o limiar de segurança e capacidade de carga dos ecossistemas da Terra, por meio do aumento de sua resiliência. / There is little information about the sustainable agribusiness for biofuels made from perennial oil forest of sociobiodiversity context. This research aimed to propose a framework and analyze the emergence, evolution and consolidation of a biodiesel filière from Macaúba, guided by sustainable development. For this, it proposes a new model by combinning tree approaches and instruments from the models sumarized as follow: The first tool model is the practical method of Munasinghe (2002): a transdisciplinary metaframework, the Sustainomics, that has evaluative techniques of unsustainable activities. The second is the Filière Method, composed by the following mesoanalitics guidelines: technology, strategy and relationships (MONTIGAUD, 1991). The third envolves levels of Evolutionary Economics, derivatives from the Framework Micro-Meso-Macro (DOPFER FOSTER and POTTS, 2004). These approaches and some instruments used from the models, fit together the dimensions and elements of integration, to propose the mentioned new model entitled as a neologism “Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics”, designed to identify and to recommend urgent priorities in the present and in the future, to the studied chain. This research is exploratory, qualitative, within collected primary and secondary data. Primary data was interviews with video recorded. From the seven rings of chain (Macaúba filière) that were identified, the study case addresses the production systems, some adopted and some prospected, in Agricultural and Agroindustry rings, between the period from 2004 to 2009, the geographical locus of the municipality of Montes Claros/MG. The results were analyzed based on the instruments, as follow: Action Impact Matrix, Diagnostic analysis of systemic filière, and two Evolutionary Economics techniques: Trajectory Micro as an Analytical Domain and Analysis of the Meso Generic Trajectory. It was identified, first, that: the six companies operating directly in emerging filière, none operates exclusively Macaw Palm’s biodiesel. The Second consideration refers that it is possible a win-win game, for the analysed case, making possible coexistence: “improving the lives of poor people and addressing the issue of climate change” (MUNASINGHE, 2002). The results pointed the recomendations of progressive replacement of: 1) The fossil diesel through biofuels, which have life cycle, in fact, renewed; 2) The raw materials of the annual cycle, with low yields of biofuels from monocultures, through polycultures of perennial crops, from biodiversity biomes, focusing on Macaw Palm, for Savannah. 3) the monoculture of soybeans for biofuels, through raw-material derived from Non-Timber Natural Forest resources, organized in successional agroforestry system of production, with innovation for use inthe areas of Legal Reserves, as sustainable production fields. 4) The entropy of deforestation, through the Syntropy; 5) From biodiesel through the direct use - SVO: unleash the technological process of wrong agroindustrial transesterification of vegetable oil to remove the glycerin from the oil; 6) From diesel cicle engines non-adiabatic, produced and used in Brazil through new available technologies: to operate at higher temperatures to burn, as biofuel, as well as glycerin, to avoid unnecessary waste generation. Summing up, the analysis model for perennial crops, oilseeds sustainable (Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics), used in this case study can be applied to other similar cultures, in order to prevent sudden disasters, without delay, eliminating activities that threaten to exceed the safety threshold and carrying capacity of Earth's ecosystems, by increasing its resilience.

A influência das variáveis associadas ao laser como a fluência, o comprimento de onda, e a duração do pulso, assim como as relacionadas às propriedades das amostras, como a distribuição do tamanho das partículas e as características químicas da matriz, foram avaliadas visando à determinação quantitativa de macro- (P, K, Ca, Mg) e micronutrientes (Cu, Fe, Mn, Zn, B) em pastilhas de materiais vegetais por espectrometria de emissão óptica com plasma induzido por laser (LIBS). Os efeitos da distribuição do tamanho das partículas e da fluência do laser foram investigados a partir da análise de amostras peneiradas (150-20 µm) empregando-se um sistema LIBS, em regime temporal de nanossegundos (ns-LIBS), montado com um laser de Nd:YAG a 1064 nm (pulsos de 5 ns e 360 mJ)e um espectrômetro com óptica Echelle e detector ICCD. Observou-se um aumento na sensibilidade e na precisão das medições com a diminuição do tamanho das partículas usadas no preparo das pastilhas, e uma diminuição dos efeitos de matriz causados por diferenças no tamanho das partículas, quando pastilhas preparadas com partículas < 75 µm foram analisadas com pulsos de 50 J cm-2. Verificou-se uma melhora significativa na exatidão das medições de Mg, Fe, Mn e Zn feitas em um conjunto de pastilhas de folhas de cana-de-açúcar (partículas < 75 µm) empregando-se esta fluência. Em uma segunda etapa, observou-se que variações no comprimento de onda do laser de Nd:YAG (1064, 532, 355 e 266 nm) não influenciaram de maneira significativa a precisão e exatidão das medições em pastilhas de folhas de cana-de-açúcar, obtendo-se correlações lineares entre as intensidades dos sinais de emissão e as correspondentes frações de massa dos analitos. Variações no comprimento de onda do laser de Nd:YAG não afetaram a análise de um conjunto heterogêneo de amostras, composto por pastilhas de folhas de plantas de diferentes espécies, como soja, cana-de-açúcar, milho, citros, café, por exemplo, por ns-LIBS. No entanto, diferentemente do observado para o conjunto de pastilhas de folhas de cana-de-açúcar, observou-se, uma baixa correlação (r cal < 0,90) entre as frações de massa de Ca, Mg, P, Cu, Fe, Mn e Zn determinadas por ns-LIBS e os valores de referência, o que demonstra a baixa robustez de ns-LIBS frente às variações na composição química das matrizes. Posteriormente, analisou-se este conjunto heterogêneo de amostras com sistema LIBS, em regime temporal de femtossegundos (fs-LIBS), montado com laser de Ti:Safira (pulsos de 60 fs e 1,65 mJ) e espectrômetro com óptica Czerny-Turner e ICCD. Demonstrou-se que o uso de pulsos em regime de fs proporcionou calibrações e validação menos dependentes da composição química das matrizes. As frações de massa de Ca, Mg, P, Fe e Mn previstas por fs-LIBS foram estatisticamente concordantes com os valores de referência, independentemente do modelo de calibração usado. Além disso, o uso de calibração multivariada melhorou a capacidade preditiva de ns-LIBS, assemelhando-se à de fs-LIBS. Concluiu-se que o emprego de fs-LIBS foi a estratégia mais robusta e que ofereceu maior flexibilidade à variabilidade matricial / The influence of laser properties, such as fluence, wavelength and pulse duration, as well as sample characteristics, such as particle size distribution and chemical matrix composition, was evaluated aiming at the quantitative determination of macro- (P, K, Ca, Mg) and micronutrients (Cu, Fe, Mn, Zn, B) in pellets of plant materials by laser-induced breakdown spectroscopy (LIBS). Firstly, the effects of particle size distribution and laser fluence on the analysis of pellets (test samples) prepared with sieved samples (from 150 to 20 µm apertures) were investigated. Experiments were carried out with a nanosecond LIBS (ns-LIBS) system by using a Q-switched Nd:YAG laser at 1064 nm (5 ns; 360 mJ) and a spectrometer with Echelle optics and intensified charge-coupled device (ICCD) detector. Results indicated that smaller particles yielded to sensitivities\' enhancement and attained better measurements\' precision. Moreover, matrix effects were reduced by analyzing pellets prepared from < 75 ?m sieved fractions and pulses of 50 J cm-2. In addition, there was a significant improvement on accuracy of Mg, Fe, Mn and Zn measurements in a set of test samples of sugarcane leaves by using this fluence. In a second experiment, variations in the Nd:YAG laser wavelength (1064, 532, 355 and 266 nm) did not affect the analysis of test samples of sugarcane leaves, and provided linear correlations between emission signal intensities and corresponding analytes mass fractions. In addition, variations within Nd:YAG laser wavelength did not affect the analysis of a heterogeneous sample set composed by pellets of leaves from different crops, such as soy, sugarcane, maize, citrus and coffee by ns-LIBS. However, in contrast to previous findings, the univariate calibration models for ns-LIBS presented lower linearity (r cal < 0.90) for Ca, Mg, P, Cu, Fe, Mn and Zn, no matter the laser wavelength used for the analysis. These circumstances reflect the low robustness of ns-LIBS to variations within matrix chemical composition among test samples. Afterwards, test samples from different crops were analyzed by a femtosecond LIBS (fs-LIBS) by using a Ti:Sapphire laser, including a mode-locked oscillator and an ultrafast amplifier (60 fs; 1.65 mJ per pulse), and a spectrometer with Czerny-Turner optics and ICCD. Findings indicated that the pulse duration was a decisive variable for providing accurate quantification of nutrients in different plant species, which present substantial differences in terms of matrix chemical composition. Close agreement between Ca, Mg, P, Fe and Mn mass fractions predicted by fs-LIBS and those determined by ICP OES was evidenced, whatever the modeling approach used. Contrarily, for ns-LIBS analysis of test samples from different crops, only the use of multivariate partial least squares (PLS) regression appears capable for resolving the non-linear transformations of the emission intensities according to the physical mechanisms governing this temporal regime of ablation. Thus, when using multivariate modeling, the figures-of merit reflecting the predictive capabilities of ns-LIBS resemble to those achieved by fs-LIBS. Either way, fs-LIBS is a more robust approach that better offers larger flexibility to the matrix variability

L'acte d'achat de produits monastiques est un moment de rencontre entre deux mondes que tout semble opposer : le monde monastique, silencieux et détaché des biens matériels, et le monde sécularisé de la consommation, bruyant et matérialiste. Notre recherche très contextualisée se place dans la perspective culturelle de la consommation. La problématique est centrée sur la compréhension de l'influence des contextes sur le contenu de l'expérience vécue par l'acheteur de produits monastiques alimentaires et cosmétiques. Notre recherche empirique, fondée sur une approche qualitative de nature ethnographique, est pratiquée en immersion dans le monde de l'économie monastique française. Nous interrogeons les acheteurs sur le sens qu'ils donnent à leur expérience d'achat de produits monastiques dans des magasins physiques d'abbayes, sur une galerie marchande virtuelle d'abbayes, et dans une enseigne physique laïque. Un premier palier de résultats apporte une compréhension contextualisée de l'écosystème monastique, et du contenu de l'expérience d'achat dans trois types de points de vente. Ils mettent notamment en lumière les liens étroits entre achat, don, plaisir et partage, ainsi que la dimension patrimoniale des produits. Un second palier de résultats moins contextualisés défend la thèse que le point de vente physique est un instrument de transfert de sens des contextes extérieurs vers le cœur de l'expérience. Nous mettons ainsi en lumière les limites du e-commerce pour les produits ancrés dans l'histoire et le territoire, et proposons aux décideurs des pistes d'adaptation pour les sites marchands. / The act of purchasing a monastic product is a situation when two apparently contradictory worlds come together: the monastic world, silent and detached from material goods, and the secular world of consumption, noisy and materialistic. Our research is highly contextualised and looks at consumption from a cultural perspective. The aim of this research is to understand in which way contexts influence the content of the experience when buying monastic food products and cosmetics. Our empirical research is qualitative, ethnographic in nature, and is carried out inside the world of the French monastic economy. We ask purchasers about the meaning they give to their experience of buying monastic products from abbey shops, from an abbeys' virtual marketplace, and from a secular branded outlet. The first-level results bring a contextualised understanding of the monastic ecosystem, and of the dimensions of the buying experience at the three types of shops. They particularly highlight the close links between purchasing, giving, enjoyment and sharing, and also the patrimonial aspect of these products. The second-level results are less contextualised and support the theory according to which the physical point of sale is the instrument through which the meaning of the external contexts is transferred into the heart of the experience. We are thus able to highlight the limitations of e-commerce for products that are deeply anchored in history and territory, and we advise decision-makers on how best to adapt their strategies for online channels.

L'objectif de cette thèse est de caractériser l'influence de la présence d'obstacles dans les passes à poissons à fentes verticales. Deux types d'éléments sont couramment insérés, à l'heure actuelle, dans les passes : les seuils et les macro-rugosités. Dans un premier temps, l'effet de ces deux dispositifs à la fois sur l'écoulement et sur le comportement des poissons est étudié. Dans le but de favoriser le passage des petites espèces à travers le dispositif de franchissement, une solution technique est ensuite proposée, sous la forme de plusieurs rangées de cylindres flexibles placées en sortie de fente. La caractérisation du comportement hydraulique d'une passe à poissons équipée de ces obstacles est effectuée par des mesures expérimentales de niveau d'eau à l'aide de sondes acoustiques et des mesures de vitesses tridimensionnelles avec un vélocimètre acoustique à effet Doppler (ADV). La base de données générée par ces mesures est ensuite utilisée pour définir une loi de dimensionnement, qui prend en compte les paramètres influençant le fonctionnement hydraulique de l'ouvrage en vue d'améliorer sa conception. Les simulations numériques 3D instationnaires URANS et LES de l'écoulement permettent une analyse volumique fine des grandeurs caractéristiques de la turbulence qui règne dans les bassins en fonction du type d'obstacle inséré. En obstruant une partie de la fente, la présence d'un seuil accentue la tridimensionnalité de l'écoulement tandis que les macro-rugosités créent une zone de plus faible vitesses et des abris utilisables par les espèces de fonds. L'insertion des structures souples permet une meilleure dissipation de l'énergie du jet et réduit l'énergie cinétique turbulente dans une partie du volume des bassins. Les manipulations réalisées avec différentes espèces de poissons, permettent de mieux comprendre l'effet de la modification des grandeurs cinématiques de l'écoulement, par l'insertion d'obstacles, sur le comportement des poissons pour pouvoir adapter les passes à poissons existantes aux espèces dotées de faibles capacités de nage. / The aim of this work is to characterize the influence of two kinds of obstacles, sills and macro-roughnesses, on the flow inside a vertical slot fishway (VSF) and the behavior of several species of fish. Another objective is to study a technical solution to allow the passage of small fish species, which take the form of flexible cylinders placed in the jet at the entrance of each pool of the VSF. A hydraulic characterization is made by experimental measurements of the water level in each pool with acoustic sensors and by measurements of three-dimensional velocity components with an acoustic Doppler velocimeter (ADV). The data acquired by these measurements are then used to define a predictive law that takes into account the presence of sills or macro-roughnesses, to help the design of devices that are as efficient as possible. Unsteady RANS and LES three-dimensional numerical simulations of the flow allow performing a careful volume analysis of the turbulence characteristics inside the pools when obstacles are presents in the flow. By obstructing a part of the slot, sills enhance the three-dimensionality of the flow while macro-roughnesses generate a low velocity layer and shelters for benthic species. Flexible elements produce a better dissipation of the energy of the jet and reduce the turbulent kinetic energy in a part of the volume of the pools. The effect of the modification of the flow kinematic properties, by the presence of obstacles, on the behavior of various fish species is evaluated. It provides important insights on how to adapt the flow in existing fishways to fish species with low swimming capacity.

Les nuages jouent un rôle important dans le cycle de l'eau et de l'énergie au sein de l'atmosphère. De plus, ils représentent l'une des principales sources d'incertitudes dans les projections des modèles de climat en raison notamment de la difficulté à paramétrer les processus qui leurs sont associés ainsi que leurs interactions avec l'environnement. Dans cette thèse nous étudions les nuages de mi-niveau qui ont été beaucoup moins étudiés que les nuages bas et les nuages hauts, en se focalisant sur l’Afrique de l'Ouest. L'Afrique de l'Ouest se caractérise par une forte saisonnalité des précipitations survenant au Sahel de juin à septembre durant la période dite de mousson. Cette période coïncide également avec le maximum annuel de la couverture nuageuse. Au travers du déploiement de la station mobile ARM (Atmospheric Radiation Measurement) durant une année en 2006 à Niamey (Niger), Bouniol et al. (2012) ont documenté les différents types de nuages observés pendant la mousson et ont montré la présence récurrente de nuages vers 6 km d'altitude dont l’impact radiatif est important dans les domaines du visible et de l'infrarouge. Dans le prolongement de cette étude, l'objectif de cette thèse est donc d'analyser plus en détails ces nuages de mi-niveau en documentant leur occurrence, leur cycle diurne et leurs caractéristiques macro- et microphysiques. Nous analysons également l'environnement thermodynamique dans lequel ces nuages sont observés ainsi que leurs effets radiatifs. D’autre part, en analysant les simulations effectuées dans le cadre du projet CMIP5, Roehrig et al. (2013) ont montré une sous-estimation de ce type de nuages dans les modèles de climat. Nous documentons plus précisément ici comment les modèles de climat et les modèles à aire limitée simulent ces nuages de mi-niveau. Afin de documenter ces nuages, des observations obtenues à partir d'instruments de télédétection active déployés sur deux sites sols : Niamey au Sahel et Bordj Badji Mokhtar au Sahara ont été combinées avec les données satellites de CloudSat et CALIPSO. Ces observations ont révélé une occurrence de ces nuages tout au long de l'année avec une prédominance durant la période de mousson. Ces nuages sont majoritairement observés dans le Sud et l'Ouest de l'Afrique de l'Ouest mais s’étendent jusqu’au cœur du Sahara. Leur présence dans cette zone désertique pourrait s’expliquer par la dynamique de la dépression thermique saharienne (Saharan Heat Low). Ces nuages sont généralement fins (la plupart ont une épaisseur inférieure à 1000 m) et sont principalement composés d'eau liquide. Une méthode de clustering appliquée à ces données nous a permis d'identifier trois types de nuages : le premier avec des bases plus basses, le deuxième avec des bases plus hautes et le dernier avec de plus fortes épaisseurs. Les radiosondages et les mesures de rayonnement nous ont permis de déterminer la stratification thermodynamique dans laquelle ces nuages sont observés ainsi que d’estimer leur impact radiatif. On observe généralement des inversions de température potentielle au sommet des nuages des deux premières familles. Dans les modèles de climat, nous avons mis en évidence une forte dispersion des occurrences des nuages de mi-niveau en termes de fréquence, de position et d’extension sur la verticale et de cycle saisonnier. L'analyse des simulations régionales indique aussi une influence de la résolution spatiale et de la paramétrisation de la convection sur la modélisation des nuages de mi-niveau simulés au Sahel et sur le Sahara. / Clouds have an important impact on the water and energy fluxes within the atmosphere. They also represent one of the main sources of uncertainties of climate models projections as a consequence of the difficulty to parametrize their associated processes as well as their interactions with their environment. In this thesis mid-level clouds are studied. Such clouds have been much less studied than low clouds and high clouds and the focus is on the West Africa. West Africa is characterized by a strong seasonality in precipitation that occur in the Sahel from June to September named the monsoon season. This period also coincides with the annual maximum of the cloud cover. Taking advantage of the one-year ARM Mobile Facility (AMF) deployment in 2006 in Niamey (Niger), Bouniol et al. (2012) documented the distinct cloud types observed during the monsoon and showed a frequent occurrence of clouds around 6 km height with an important radiative impact in the surface short-wave and long-wave domains. In the continuity of this study, the aim of this thesis is therefore to analyse in more details these mid-level clouds by documenting their occurrence, their diurnal cycle as well as their macro- and microphysical characteristics. We also analyse the thermodynamical environment in which these clouds are observed and their radiative effects. In a process-oriented evaluation of CMIP5 climate models, Roehrig et al. (2013) showed an underestimation of mid-level clouds. We document more precisely here how climate models and limited-area models simulate these mid-level clouds. To document those clouds, we combine observational data from active remote sensing instruments deployed at the two groundbased sites : Niamey in the Sahel and Bordj Badji Mokhtar in the Sahara, with merged CloudSatCALIPSO satellite. These observations reveal an occurrence of those clouds throughout the year with a predominance around the monsoon season. These clouds are preferentially observed in the Southern and Western part of West Africa but extend to the heart of the Sahara. Their presence in this desert zone may be explained by the dynamics of the Saharan Heat Low. Those clouds are usually quite thin (most of them are less than 1000 m deep) and mainly composed of liquid water. A clustering method applied to this data allows us to identify three different types of clouds : one with lower bases, one with higher bases and another with larger thicknesses. Radiosondes and radiation measurements allowed us to determine the thermodynamical stratification in which these clouds are observed as well as to estimate their radiative impact. Potential temperature inversions are generally observed at the top of the clouds of the first two families. In the climate models, we showed a strong dispersion of the occurrences of mid-level clouds in terms of frequency, location and vertical extension and seasonal cycle. Analysis of regional simulations also indicates an influence of spatial resolution and of the convection parametrization on the model ability in simulating mid-level clouds in the Sahel and in the Sahara.

Les déchets plastiques s'accumulent depuis plusieurs décennies dans les océans où ils se fragmentent en particules appelés microplastiques lorsque leur taille est inférieure à 5 mm. Ces microplastiques sont retrouvés dans toutes les eaux du globe, dans les sédiments ainsi que dans de nombreux organismes marins. Le devenir physicochimique à long terme de ces particules et leur possible fragmentation en nanoplastiques sont complexes, encore peu documentés et nécessitent des études en laboratoire.Afin de comprendre les processus liés à la photodégradation et à la fragmentation des polymères dans l’environnement, mais également dans le but d’'appréhender l’évolution des fragments générés au cours de l’irradiation, un protocole de vieillissement accéléré en milieu abiotique a été mis en place sur des polymères modèles. Le suivi de l’oxydation et de la fragmentation des deux polymères étudiés,polyéthylène basse densité et polypropylène, a été mené à l’aide de techniques spectroscopiques (infrarouge, Raman), DSC, angles de contact, et microscopiques (lumière polarisée, MEB, AFM…).Ce travail a permis de mettre en évidence l’influence significative de l’environnement et de la morphologie initiale des polymères sur leurs cinétiques de vieillissement et leurs mécanismes de fissuration. Ainsi des distributions en nombres, tailles et formes de fragments très différentes ont été obtenues pour les deux polymères selon la présence d’eau. Enfin, après un long temps d’irradiation, des produits de dégradation ont pu être détectés mais la production significative de nanoplastiques n’a pas été démontrée. L'hypothèse d'une taille limite de fragmentation devrait être envisagée. / Plastic wastes have been accumulating for several decades in the oceans where they break up into particles called microplastics when their size is less than 5 mm. These microplastics are found in all earth’s waters, in sediments and in many marine organisms. Their long-term physico-chemical fate and their possible fragmentation into nanoplastics are complex, still poorly documented and require laboratory studies.In order to understand the processes related to photodegradation and fragmentation of polymers, but also in order to understand the evolution of these fragments during irradiation, an accelerated aging protocol in abiotic conditions has been set up. The oxidation and fragmentation of two model polymers, low density polyethylene and polypropylene, were monitored using spectroscopic techniques (InfraRed, Raman), DSC, contact angles and microscopic technics (light microscopy, polarized light, SEM, AFM ...).This work has demonstrated a significant influence of the environment and the initial morphology of the polymers on their kinetics of aging and cracking mechanisms. This lead to significantly different distributions in numbers, sizes and shapes of the generated fragments. Moreover, after a long time of irradiaiton, other degradation products could be detected but the significant production of nanoplastics has not been demonstrated. The possibility of a size limit below which the fragmentation rate of plastics would strongly decrease should be considered.

La République Démocratique du Congo (RDC) fut l'un des meilleurs modèles de l'exploitation aéronautique en Afrique pendant la colonisation et plus d'une vingtaine d'années après l'indépendance au point d'en être félicitée par l'Association Internationale des Transporteurs Aériens (IATA). Aujourd'hui, par contre, ce vaste pays situé au cœur de l'Afrique passe pour le mauvais élève de l'aviation civile mondiale sur le plan sécuritaire et le pire dans l'enregistrement des accidents et des catastrophes aériens depuis la libéralisation de ce secteur en 1978. Conséquence: la DOC est blacklistée par l'Union européenne depuis 2005 jusqu'à ce jour. Dans la mémoire collective et les médias, la RDC est ainsi assimilée aux crashes et aux catastrophes aériennes et le commentaire l'égratigne chaque fois que survient un accident aérien dans n'importe quel pays au monde. Cette étude s'inscrit dans la problématisation de la communication au sein des organisations. Elle questionne les nouveaux paradigmes de l'accident aérien dans le but de sa prévention en amont dans le transport aérien. La question principale concerne donc la communication en aéronautique civile. En effet, malgré l'imputabilité des occurrences comptabilisées en RDC soit à l'erreur humaine, soit à la technique, soit à l'environnement, soit à la conjonction de ces trois facteurs causaux, cette thèse doctorale démontre, dans une approche généalogico­processuelle, socio-anthropologique et macro systémique-technique aéronautique, que l'avalanche des accidents et des catastrophes aériens en RDC est consécutive à « la communication autistique», c'est-à-dire à « la normalisation de l'anormal, des dysfonctionnements, des déviances, des transgressions normatives», donc de « l'anormal normalisé» ou à un échange ou une communication procédant par les écarts aux normes de l'Organisation de !'Aviation Civile Internationale (OACI) dans un domaine très réglementé et très normalisé. Ainsi, l'étude décrit l'évolution de l'aéronautique civile congolaise des origines coloniales à ce jour. Elle fait une immersion dans les organisations ou les structures de son « collectif sécuritaire», en esquisse les types de communications, d'interactions, de relations et d'interrelations y entretenus, à savoir les incommunications, les communications paradoxales, ambigües, confuses, incompatibles, absurdes, l'aveuglement communicationnel ou déni de communication, les dialogues de sourds, communication de défense transpersonnelle, silences en tant que langue de bois. Enfin, cette recherche doctorale analyse sans complaisance les accidents et les catastrophes aériens survenus de 1990 à 2011 en ROC pour le démontrer et propose une théorie systémique du collectif sécuritaire de l'aéronautique civile comme « frein » aux pratiques communicationnelles autistiques en aviation civile. / The Democratic Republic of Congo (DRC) was one of the best models of aeronautical exploitation in Africa during colonization and over a couple of decades after independence to the extent of being congratulated by the International Air Transport Association (IATA). Today, in contrast, this huge central African country (DRC) is the bad student in world civil aviation in terms of security and the worst in terms of air accidents and disasters since the sector was liberalized in 1978. The consequence is that ORC has been blacklisted by the European Union since 2005. In the collective memory and the media, DRC is associated with crashes and air disasters so that every lime there is a plane crash anywhere in the world, reference is made to ORC. This research questions the issue of communication within organizations. New paradigms of air accidents are questioned with the aim of their prevention upstream in air transport. The main research question is about communication in civil aeronautics. As a matter of tact, even though registered occurrences in ORC have been attributed either to human error or to technology, or to the environment, or sometimes to the combination of these three factors, results of this study conducted in a genealogic-process, socio-anthropological and macro aeronautical technically-systemic approach indicate that the avalanche of air accidents and disasters in ORC is due to "autistic communication", that is, "the normalization of the abnormal, dysfunction, deviances and infringement of standards", thus 'the abnormal standardized" or through communication that proceeds by discrepancies to standards of the International Civil Aviation Organization (ICAO) in a highly regulated and standardized field. The study depicts the evolution of Congolese civil aeronautics since its colonial origins until the present, it immerses itself in the organizations or structures of its "security sector", and outlines the types of communications, interactions, relations and interrelations that occur in there including paradoxical, ambiguous, confusing, incompatible, absurd communications, non-communications, communicational blindness or denial of communication, dialog of the deaf, transpersonal defense communication, silence as waffle. Finally, the research analyzes air accidents and disasters that occurred in DRC between 1990 and 2011 without leniency to demonstrate this and suggests a systemic theory of civil aeronautics security sector as "a brake" to autistic communicational practices in civil aviation.

Les pays de l’UEMOA ont recours depuis quelques années aux Partenariats Public-Privé (PPP) pour faire face à une demande en infrastructures publiques loin d’être satisfaite par le seul budget de l’Etat. Au-delà des difficultés financières, il s’avère difficile de construire des modèles de gouvernance durables et socialement acceptables pour conduire ces processus. Ainsi notre problématique concerne l’indentification des modèles adéquats de gouvernance des PPP dans le contexte des pays de l’UEMOA. Le cadre théorique mobilisé à cet effet s’inspire de la théorie des coûts de transaction, de la théorie de l’agence, du nouveau management public et des contributions récentes à l’analyse des modèles de gouvernance de PPP. Ainsi, une grille d’analyse des données empiriques composée de quatre macro-dimensions (exogène, organisationnelle, projet et qualité du service) est déduite. Dans une posture du constructiviste pragmatique, une méthodologie qualitative basée sur deux études de cas a été privilégiée. La collecte des données, effectuée en deux phases séparées d’un an, a permis l’analyse de régularités. 42 entretiens semi-directifs, auprès des acteurs impliqués dans deux processus PPP, ont été réalisés. Il s’agit du Programme de Vérification des Importations- Nouvelle Génération (PVI-NG) au Bénin et du pont Henri Konan Bédié d’Abidjan en Côte D’Ivoire. Le traitement et l’analyse des données sont effectués à l’aide du logiciel N’vivo. Certes, l’analyse des résultats a permis d’identifier trois modèles (coercitif, normatif/mimétique et participatif) de gouvernance de PPP ; mais dans la pratique, c’est à une combinaison, des trois modèles, dosée selon le PPP qu’on assiste. Un système propositionnel de 28 principes relatifs aux trois modèles est déduit pour améliorer le management des processus PPP. / Recently, WAEMU countries have been using PPPs to meet the demand for public infrastructure which is far from being met by the state budget alone. Added to financial difficulties, difficulties in building sustainable and socially acceptable governance models for these public projects are faced. Thus, our problem concerns the identification of adequate models of PPP governance in WAEMU context. The theoretical framework mobilized for this purpose is based on the theory of transaction costs, agency theory, new public management and recent contributions to the analysis of PPP governance models. Thus, an empirical data analysis grid composed of four macro-dimensions (exogenous, organizational, project and quality of service) is deduced. In a pragmatic constructivist posture, a qualitative methodology based on two case studies was favored. The data collection, carried out in two separate phases of one year, allowed the analysis of patterns. 42 semi-directive interviews were conducted with stakeholders involved in two PPP processes. These are the New Generation-Import Verification Program (PVI-NG) in Benin and the Henri Konan Bédié Bridge in Abidjan, Côte d'Ivoire. Data processing and analysis is carried out using the N'vivo software. The results highlight three PPP governance models: coercive, normative / mimetic and participatory; but in practice, it is a combination of the three models, assayed according to the PPP. A propositional system of 28 principles relating to the three models is deduced to improve the PPP processes management.

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