Made available in DSpace on 2014-12-17T15:03:34Z (GMT). No. of bitstreams: 1 JoseFSF_DISSERT.pdf: 5192980 bytes, checksum: c2b3b9a8cbb06f679d5b9ca1b25bd740 (MD5) Previous issue date: 2014-03-10 / The aim of this study is to characterize and evaluate the Macro System of Regional Water Distribution Natal North (RNN) and Southern Regional Natal (RNS), covering 35% and 65% respectively of the Natal-RN City. The terms of the quality and quantity of water (surface and groundwater) were also evaluated in order to adjust the parameters that contribute to proper distribution and control in water reserves. The methodology of the work took place from collecting volumetric data of production capacity and distribution of the two treatment plants for Regional as well as the flow rates of wells. Yet the quantitative capacity of reservation, distribution and consumption of the main reservoirs, population numbers and consumption of members neighborhoods were collected. Data were tabulated and used in computational simulator EPANET to diagnose possible through the water balance, the offers and demands on the water supply system in the neighborhoods of the capital, linking them to specific distribution points. We also evaluated the wells in the levels of nitrate in water consumed. As a result it was found that some neighborhoods in the South Regional Natal, was ranked as critical supply situation: City of Hope, Lagoa Nova and Nova Descoberta, where demand exceeds supply. While in most Northern Regional Natal present deficiency in the supply system as: Lagoa Azul, the Parque dos Coqueiros, igap?, Amarante and Salinas. The rates of nitrate in the city were significant, but manageable with corrective and preventive measures. The averages were 12 mg /l-N in Candel?ria, 10 mg/l-N in Lagoa Nova, 9 mg/l-N in Satelite, 20 mg/l-N in Gramore and 15 mg/l-N in N. Sra. Apresenta??o. Therefore proper distribution of water abstracted and implementation of quality control ensures the supply required by the system, associated with preservation of Water Resources of the Metropolitan Region of Natal / O objetivo deste estudo ? caracterizar e avaliar o Macro Sistema de Distribui??o de ?gua da Regional Natal Norte (RNN) e Regional Natal Sul (RNS), abrangendo 35% e 65% respectivamente da Cidade do Natal-RN. As condi??es da qualidade e quantidade das ?guas (superficiais e subterr?neas) tamb?m foram avaliadas com a finalidade de ajuste aos par?metros que contribuam para adequada distribui??o e controle nas reservas h?dricas. A metodologia do trabalho se deu a partir da coleta dos dados volum?tricos da capacidade de produ??o e distribui??o das duas Esta??es de Tratamento das Regionais, assim como as vaz?es dos po?os tubulares. Foram coletados ainda os quantitativos da capacidade de reserva??o, distribui??o e consumo dos principais reservat?rios, n?mero populacional e o consumo dos bairros integrantes. Os dados foram tabulados e usados no simulador computacional EPANET que possibilitou diagnosticar, atrav?s do balan?o h?drico, as ofertas e demandas no sistema de abastecimento de ?gua nos bairros da capital, associando-os nos pontos espec?ficos de distribui??o. Foram tamb?m avaliados os po?os tubulares quanto aos n?veis de Nitrato na ?gua consumida. Como resultado verificou-se que alguns bairros da Regional Natal Sul, foi classificado em situa??o cr?tica de abastecimento como: Cidade da Esperan?a, Lagoa Nova e Nova Descoberta, onde a demanda supera a oferta. Enquanto na Regional Natal Norte a maioria apresentaram defici?ncia no sistema de abastecimento como: Lagoa Azul, Parque dos Coqueiros, igap?, Amarante e Salinas. Os ?ndices de Nitrato na cidade apresentaram signific?ncia, por?m, control?vel com medidas corretivas e preventivas. As m?dias foram 12 mg/l-N em Candel?ria, 10 mg/l-N em Lagoa Nova, 9 mg/l-N em Sat?lite, 20 mg/l-N em Gramor? e 15 mg//-N em N. Sra da Apresenta??o. Portanto a adequada distribui??o da ?gua captada e a implementa??o de controle de qualidade garante o suprimento requerido pelo sistema, associados a preserva??o dos Recursos H?dricos da Regi?o Metropolitana de Natal

Este trabalho se situa na fronteira entre os estudos culturais e os estudos lingüísticos. Ele tem como objetivo observar possíveis diferenças em termos de organização de gênero e escolhas lexicais entre os anúncios pessoais feitos por gays e heterossexuais do sexo masculino. O corpus de análise consiste de quarenta anúncios retirados de dois sites de encontros da Internet, sendo que vinte são originariamente escritos por gays e os outros vinte por heterossexuais do sexo masculino. A base desta pesquisa se encontra nos trabalhos de Swales (1990) e Bhatia (1993) sobre a descrição de gêneros e no trabalho de Hoey (1997) sobre narrativas eróticas. Deste último retiramos alguns conceitos sobre a auto-descrição e a descrição do objeto de desejo. Inicialmente, os anúncios eletrônicos pessoais são comparados com anúncios pessoais impressos (cf. Shalom 1997), na tentativa de verificar como os anúncios impressos podem ter se adaptado ao meio digital. Num segundo momento, a análise se concentra na aplicação do sistema de Avaliação (ou Appraisal) de Martin e White (2005) a fim de caracterizarmos como os gays e heterossexuais do sexo masculino avaliam a si próprios e a seus objetos de desejo. A dissertação sugere que há diferenças relacionadas ao posicionamento atitudinal dos gays e heterossexuais, especialmente em relação à utilização de Afeto. Observam-se diferenças também não previstas por nossas perguntas de pesquisa, que não podem ser atribuídas nem às organizações diferentes dos sites, nem às escolhas lexicais dos anunciantes, mas sim aos tipos de sites e audiências escolhidos pelos anunciantes / The present work lies on the borderline of cultural and linguistic studies. It aims at examining whether there are differences concerning genre organization and lexical choices in ads filled in by gay and heterosexual males. The corpus consists of forty ads from two dating sites on the internet: twenty are originally written by gay males and the other twenty are written by heterosexual males. This research draws on works such as Swales (1990) and Bhatias (1993) on genre description and on Hoeys (1997) on erotic narratives. From the latter we have borrowed a few key concepts to help us analyze self and other description. At an early stage, the internet ads are compared to printed ads (cf. Shalom 1997) in an attempt to check how these ads should have adapted to the digital medium. Afterwards, we resort to Martin and Whites (2005) Appraisal system so as to characterize how gays and heterosexuals see themselves and their desired others. The dissertation suggests that there are differences related to the attitudinal positioning of gays and heterosexuals, particularly in the use of Affect. There are also findings unforeseen at the beginning of the research. In other words, these differences do not come down either to the variation in the organization of the sites, or to the lexical choices of the advertisers, but rather to the kind of site chosen by the advertisers

Chemical and physical attributes of an Acrustox subjected to different management systems were evaluated. The experiment was conducted at the Fazenda do Glória/UFU since 2000. The field experimental area was conducted during seven years, in a randomized block design, to evaluate some chemical and physical attributes of the soil, at depths of 0-5, 5-15 and 15-30 cm, for different management systems (conventional and conservationist). The parameters examined were: density, porosity, macro and microporosity, aggregate stability, total organic carbon (TOC), phosphorus (P), calcium (Ca2+), magnesium (Mg2+), potassium (K+), nitrogen (N) and aluminum (Al3+). Statistical differences were found between conventional and conservationist treatments. The values indicated a density increase with the depth, combined with porosity decrease as the relationship macro/micropores and with lower aggregate stability in conventional system in comparison with the conservationist systems. Statistical differences of the chemical attributes of soil, between the conservationist and conventional treatments, were found only at the top 5 cm of the soil, only for the elements Ca, P and K. Aluminum correction was more efficient in the conventional system, due to lime addition in the soil, independent of gypsum addition. / Foram avaliados atributos físicos e químicos de um Latossolo Vermelho distrófico submetido a diferentes sistemas de preparo do solo. O experimento foi conduzido na Fazenda do Glória/UFU desde o ano 2000. A área experimental de campo, disposta num esquema de delineamento em blocos casualizados, foi conduzida durante sete anos para avaliar alguns atributos físicos e químicos do solo, nas profundidades de 0-5; 5-15 e 15- 30 cm, para diferentes sistemas de manejo (convencional e conservacionistas). Os parâmetros analisados foram: densidade, porosidade total, macro e microporosidade, estabilidade de agregados, carbono orgânico total (COT), fósforo (P), cálcio (Ca2+), magnésio (Mg2+), potássio (K+), nitrogênio (N) e alumínio (Al3+). Foram verificadas diferenças estatísticas entre os tratamentos conservacionistas e convencional. Os dados indicaram aumento da densidade com a profundidade, conjugado com redução da porosidade total, bem como da relação macro/microporos e com a menor estabilidade de agregados no sistema convencional, em relação aos sistemas conservacionistas. Para os atributos químicos do solo, diferenças estatísticas entre os tratamentos conservacionistas e convencional ocorreram apenas nos primeiros 5 cm do solo, somente para os elementos P, Ca e K. A correção do Al foi mais eficiente no sistema convencional, devido à incorporação do calcário ao solo, independente da aplicação de gesso agrícola. / Mestre em Agronomia

Usar ativos financeiros para extrair as expectativas de mercado para algumas variáveis macroeconômicas é uma prática comum na literatura de Macro-Finanças. Nessa dissertação utilizamos títulos brasileiros para extrairmos as expectativas tanto do câmbio quanto da inflação com o uso de fatores latentes do tipo Nelson-Siegel. No primeiro capítulo desenvolvemos um modelo que tenta incorporar expectativas do mercado financeiro com os fundamentos macroeconômicos dessa variável. O modelo desenvolvido aqui difere dos modelos anteriores ao permitir volatilidades condicionais que parecem ser muito importantes no mercado cambial. Os resultados encontrados aqui indicam que os modelos com os fatores latentes e as variáveis macroeconômicas tem um poder de previsão melhor do que os modelos puramente macroeconômicos. Além disso, parece haver uma relação entre as variáveis macroeconômicas e a curva de diferencial de juros entre os países. Já no segundo capítulo utilizamos o diferencial entre rendimentos dos títulos reais e nominais usadas como preditores da inflação. O modelo aqui apresentado faz uma decomposição desse diferencial de juros, em prêmios de risco e inflação implícita usando um modelo paramétrico baseado em condições de não-arbitragem. As estimações da de inflação implícita do modelo se mostram estimadores não viesados da inflação futura para horizontes mais curtos e carregam informação para horizontes mais longos. Além disso, mostram resultados superiores que o uso somente do diferencial / Use financial assets to extract market expectations for some macroeconomic variables is a common practice in Macro-Finance literature. In this dissertation we use Brazilian securities to extract the expectations of both the exchange rate as inflation using Nelson- Siegel factors. In the first chapter we developed a model that incorporates these financial market expectations with macroeconomic variables, which are the foundations of this variable. The model developed here differs from previous models by allowing conditional volatilities that seem to be very important in the foreign exchange market. The study findings indicate that the models with latent factors and macroeconomic variables has better preditive power than purely macroeconomic models. In addition,indicates that there is a relationship between macroeconomic variables and the interest rate differential curve between countries. In the second chapter we use the spread between real and nominal bonds used as predictors of inflation. The model presented here is a decomposition of this interest differential in risk premiums and implied inflation using a parametric model based on no-arbitrage conditions. Estimates of implied inflation are non biased estimators of future inflation for shorter horizons and carry information over longer horizons. In addition, the implied inflation has superior results than that only using the differential

A cavitação e a dinâmica de bolhas são tópicos bastante recorrentes na literatura, devido sobretudo a seus efeitos em diversos tipos de fenômenos, como transferência de calor e escoamento em tubos. Considerando fases líquidas, sabe-se que estas estruturas de cavidade estão normalmente associadas ao equilíbrio metaestável, alcançado devido a quedas locais de pressão ou ao superaquecimento de uma substância pura (ou quase). Nestes casos é necessária a inicialização da mudança de fase através de algum mecanismo adequado, o qual gera uma sequência rápida de fenômenos. Apesar de comumente associado a danos, recentemente vários estudos vêm mostrando aplicações práticas deste tema, além de um campo ainda pouco explorado, que é o das macro cavidades. Essas cavidades podem ser geradas através do aquecimento de água a baixa pressão, sob condições específicas, criando sequências explosivas e formando movimentos como pistão para a água no interior de um invólucro convenientemente dimensionado. Este fenômeno mostra-se semelhante em diversos aspectos às micro cavidades, mais especificamente às cavidades próximas a superfícies livres, embora, sem dúvida, em escala muito maior. Os aspectos mencionados foram filmados com câmeras de alta velocidade e as características observadas foram comparadas com aquelas observadas em micro escala. Vários testes foram desenvolvidos de forma a melhor entender a dinâmica da formação e colapso dessas estruturas, sobretudo levando em conta um comportamento mais unidimensional para a evolução da bolha. Através de várias aproximações e análise de diferentes hipóteses para a variação de pressão e para a força de resistência, soluções analíticas e numéricas foram obtidas para a força exercida no fundo do contêiner e para a expansão e colapso das bolhas ao longo do tempo. As soluções propostas, em comparação com os dados experimentais, mostraram boa concordância entre si, sugerindo que os aspectos fundamentais da dinâmica da cavidade foram devidamente considerados e quantificados. / Cavitation and bubble dynamics are fairly recurring topics in literature, mostly due to their effects in various types of phenomena such as heat transfer and flow in pipes. Considering liquid phases, it is known that these cavity structures are normally associated with the metastable equilibrium, reached due to local pressure drop or overheating of a pure substance (or nearly so). In these cases, the phase change require a startup via some appropriate mechanism, which generates a fast sequence of phenomena. Although commonly associated with damage, recently several studies shown practical applications of these topics, and a still little explored field emerged, which is the field of macro cavities. These cavities can be generated by heating water at a low pressure, under specific conditions, creating an explosive sequences and forming piston like movements for the water inside a properly scaled casing. This phenomenon appears to be similar in many aspects to micro cavities, more specifically for cavities near free surfaces, although, without doubt, on a much larger scale. The mentioned aspects were filmed with high-speed cameras and the main features were compared with those observed in micro scale. Several tests have been developed to better understand the dynamics of the formation and collapse of these structures, especially taking into account a more one-dimensional behavior to the evolution of the bubble. Through various approximations, and analysis of different assumptions for the variation of pressure and the resistance force, analytical and numerical solutions were obtained for the force exerted on the bottom of the container and the expansion and collapse of bubbles over time. The proposed solutions in comparison with experimental data showed good agreement between each other suggesting that the fundamental aspects of the dynamics of the cavity were properly considered and quantified.

Les mousses de polyuréthane (PU) hautement poreuses sont largement utilisées dans différentes industries pour dissiper l’énergie des ondes sonores et vibratoires. La propagation des ondes acoustiques dans ces matériaux poroélastiques est décrite à partir d’un ensemble de paramètres physiques connus sous le nom de paramètres de Biot (pour les matériaux isotropes, ils sont composés de 5 paramètres non acoustiques et de 4 paramètres mécaniques). Il est bien connu que les propriétés macroscopiques dépendent intrinsèquement des propriétés de la microstructure de la mousse. Ainsi, une compréhension claire des corrélations entre la structure interne des mousses de PU et leurs paramètres de Biot ainsi que la contribution de chaque paramètre, soit microscopique ou macroscopique, sur l’indicateur vibroacoustique désiré est d’un intérêt majeur au stade précoce de la conception et de l’optimisation de ces matériaux poroélastiques. Le développement d’un modèle micromacro qui corrèle les propriétés de la microstructure aux paramètres macroscopiques de Biot est donc nécessaire. Récemment, un modèle qui corrèle les propriétés de la microstructure des mousses PU hautement poreuses à leurs propriétés non acoustiques a été présenté par Doutres et coll. [24, 25]. Dans cette étude, les propriétés de la microstructure (dimensions de la cellule et taux de réticulation) sont d’abord caractérisées par un microscope électronique à balayage (SEM). Ensuite, l’effet du taux de réticulation (mesurant le pourcentage de fenêtres ouvertes), de la taille des cellules et de la densité relative sur les propriétés mécaniques de la mousse de polyuréthane a été élucidé à l’aide d’un modèle numérique. Se basant sur ce modèle, un modelé analytique existant, qui corrèle les propriétés de la microstructure de mousses PU entièrement réticulées à ses propriétés mécaniques, a été revu et corrigé pour tenir compte de l’effet important du taux de réticulation. En combinant le modèle de Doutres avec le modèle mécanique développé dans cette thèse, un modèle micro-macro complet est ainsi obtenu. Utilisant ce modèle, l’impact de la variabilité de la microstructure et la contribution de chacun des paramètres microstructuraux à la réponse vibroacoustique ont été étudiés utilisant une méthode d’analyse de sensibilité globale (FAST). La méthode FAST a été utilisée pour identifier l’impact de la microstructure sur, premièrement, les paramètres de Biot-Allard et, deuxièmement, sur les indicateurs vibroacoustiques (absorption et perte par transmission) des mousses de polyuréthane poroélastiques. Une fois les modèles micro-macro et la contribution des propriétés de la microstructure connus, la performance vibroacoustique de la mousse a été optimisée. Ainsi nous avons testé numériquement la performance acoustique de mousses homogènes et de mousses graduellement structurées (variation de propriétés suivant l’épaisseur de la mousse). Cette étude ouvre ainsi de nouvelles portes pour concevoir des mousses PU innovantes avec une microstructure modifiée et des performances vibroacoustique améliorées. / Abstract : Highly porous polyurethane (PU) foams are widely used in different industries to dissipate the energy of sound and vibration waves. Propagation of acoustic waves in such poroelastic materials is explained based on a set of physical parameters known as the Biot's parameters (for isotropic materials these are comprised of 5 non-acoustical parameters and 4 mechanical parameters). These macroscopic properties are inherently dependent on the microstructure properties of the foam. Hence, a clear understanding of correlations between the internal structure of PU foams and their Biot's parameters and the contribution of each parameter, either microscopic or macroscopic, to classical vibro-acoustic indicators is of utmost interest at the early stage of design and optimization of such poroelastic materials. In consequence, a micro macro model that correlates microstructure properties to macroscopic Biot's parameters is needed. Recently, a model that correlates the microstructure properties of highly porous PU foams to their non-acoustical properties was presented by~\citet{Doutres2011,Doutres2013}. In this study, micro-structure properties (strut length, strut thickness, and open pore content) are first characterized using a Scanning Electron Microscope (SEM). Then, a numerical study is performed to elucidate the effect of open pore content (known as reticulation rate), cell size, and relative density on the mechanical properties of polyurethane foam. Based on this study, an existing analytical model~\cite{Gong2005} that correlates fully reticulated unit cell microstructure properties of PU foams to its mechanical properties is corrected and updated to account for these important parameters. Combined with Doutres’ model, the proposed extension lead to a full micro-macro model for predicting the acoustic performance of PU foams from its microstructure. Using this model, the contribution of the unit cell parameters and effect of their variability on classical vibro-acoustic indicators (absorption and transmission loss) is investigated using a global sensitivity analysis method (FAST). The FAST method is used to identify the impact of microstructure role on, first, the Biot-Allard parameters and, second, on vibro-acoustical indicators of poroelastic polyurethane foams. Based on this sensitivity analysis study, the developed micro-macro model, is used to design both optimum homogeneous foam and functionally graded foams (properties optimally varnish along the thickness of the foam) targeting specific in absorption and/or transmission loss problems. This study opens thus a new door to design innovative PU foams with modified micro-structure and improved vibro-acoustical performance.

Ces travaux portent sur la déformation des aciers au cours de leur solidification, au moyen d'une expérience instrumentée et de sa simulation numérique. L'étude est focalisée sur deux phénomènes induits par la déformation : la fissuration à chaud et la macroségrégation. L'expérience consiste à poinçonner latéralement un lingot de 450 kg, alors que son cœur est encore partiellement liquide.L'expérience est instrumentée thermiquement et mécaniquement. Les lingots sont analysés, visuellement en termes de lieu et de fréquence d'apparition de fissures, et par microsonde pour les ségrégations chimiques.Pour la fissuration à chaud, une simulation numérique 3D par éléments finis est mise en œuvre avec le logiciel Thercast®, dans lequel a été implanté un critère d'amorçage de fissure basé sur la déformation plastique cumulée en fin de solidification, entre deux valeurs critiques de fraction de liquide. La comparaison entre simulations et observations montre le caractère prédictif du critère.La simulation numérique de la macroségré-gation est réalisée avec le logiciel R2sol qui résout simultanément la déformation du solide et l'écoulement du liquide. La simulation montre la redistribution des solutés dans le cœur du lingot sous l'effet de la compression du squelette solide et de l'écoulement du liquide, induits par le poinçonnement. Elle reproduit qualitativement les mesures expéri-mentales mais sous-estime l'amplitude des hétérogénéités de composition chimique. Une discussion des résultats permet de dégager des pistes permettant d'espérer une prédiction quantitative dans le futur.Les deux thématiques étudiées ont mis en relief la nécessité d'une bonne modélisation des phénomènes de microségrégation des alliages multiconstitués. Un modèle a été spécifiquement développé à cet effet. / Experimental and numerical studies of hot tearing and macrosegregation formation during steel solidification are reported. On one hand, an ingot punching test is considered. It consists of the application of a deformation at the surface of a solidifying 450 kg steel ingot. On the other hand, finite element thermo-mechanical modelling of the test is used.For hot tearing analysis, 3D finite element modeling is applied by use of Thercast® software. The time evolution of the strain tensor serves to evaluate the possibility for hot tear formation with a Hot Tearing Criterion (HTC). The HTC compares the local accumulation of strain over a certain solidification interval with the expression of a critical value proposed in the literature. Detailed comparisons reveal an excellent capability of the HTC to predict the formation of hot tears.For macrosegregation analysis, a two-phase formulation has been implemented (R2sol software), in which the velocities of the liquid and solid phases are concurrently solved for. The simulation shows how solutes are redistributed through the central mushy zone of the ingot under the effect of the com-pression of the solid phase resulting from the punching of the solid shell. The simulation proves its capability to reproduce the main experimental trends. However the predicted intensity of macrosegregation is lower than measured. Through discussion and analysis of different numerical sensitivity tests, critical material parameters and model improvements are identified in view of achieving better quantitative predictions in the future.The two topics studied have clearly shown the need for a good modelling of microsegregation phenomena in multicomponent alloys. A numerical model has especially been developed and implemented in the two software packages.

L’Hydroxypropyle méthylcellulose (HPMC) constitue un des polymères les plus utilisés pour la production de films destinés aux applications pharmaceutiques (gélules, comprimés, etc.). Afin de contrôler les propriétés physico-chimiques de films HPMC, des additifs sont fréquemment incorporés pendant la formulation du film: ce sont dans la plupart des cas un lubrifiant hydrophobe (acides gras) ou un plastifiant hydrophile (le polyéthylène glycol). L’objectif principal de ce travail est d’étudier les propriétés physico-chimiques en volume et en surface des films HPMC formulés aux échelles nanoscopique et macroscopique. Les propriétés volumiques concernent l’isotherme de sorption de l’eau, le taux de transmission de la vapeur d’eau, les propriétés thermiques et mécaniques des films. Les caractéristiques de surface ont été exploitées en termes de structuration, morphologie, séparation de phase, énergie de surface, adhésion et friction de films HPMC formulés. A l’échelle nanoscopique, la microscopie à force atomique en mode contact et en mode friction est un outil puissant pour étudier la nanoadhésion et la nanofriction. A l’échelle macroscopique, le test de tack et le tribomètre ont permis d’accéder aux propriétés d’adhésion et tribologiques. La présente étude souligne que les propriétés de films HPMC dépendent fortement de la nature et de la concentration de l’additif, et/ou de l’affinité avec l’eau. Elle montre aussi que la compatibilité HPMC-additif semble un facteur intéressant pour la variation des propriétés de surface de films HPMC formulés, et que la formulation est un moyen efficace pour contrôler les propriétés physico-chimiques de films à base de biopolymères. / Hydroxypropyl methylcellulose (HPMC) constitutes one of the most dedicated polymers used in the production of film coatings for pharmaceutical applications (capsules, tablets, etc.). In order to control the physicochemical properties of HPMC films, additives are frequently incorporated during film formulation: these are in most cases hydrophobic lubricant (like fatty acids) or hydrophilic plasticizer (like polyethylene glycol). The main objective of this work is to study the bulk and the surface physicochemical properties of HPMC formulated films at nanoscopic and macroscopic scales. Bulk properties include moisture sorption isotherms, barrier properties, thermal and mechanical properties. The surface characteristics have been explored in terms of structuration, surface morphologies, surface phase separation, surface energy, adhesion, and friction properties of HPMC-formulated films. At nanoscale, atomic force microscopy in contact mode and in friction mode is a powerful tool for studying nanoadhesion and nanofriction. At macroscale, tack test and pin-on-disk tribometer were conducted to access adhesion and tribological properties. The present study underlines the strong dependence of film properties on additive nature, concentration, and/or water sensitivity. It also shows that first the HPMC-additive compatibility seems to be an interesting factor behind the variation of surface properties of HPMC-formulated films, and second that formulation is an effective way to tune physicochemical properties of biopolymer-based films.

Les cavités artificielles funéraires sont à la fin de la Préhistoire en Méditerranée occidentale un type d’architecture privilégié. La compréhension de la chaîne opératoire de construction des hypogées est essentielle afin de déterminer quelles techniques et stratégies entrent en jeu dans la mise en place de ces architectures souterraines. C’est dans le cadre de cette thèse qu’une méthode a été développée sur le sujet. Celle-ci se présente en trois axes : l’étude technologique du macro-outillage de creusement, l’analyse à l’aide de la photogrammétrie des traces présentes sur les parois des hypogées et l’expérimentation permettant de confirmer ou d’infirmer les hypothèses émises. Ces trois axes ont été développés dans des contextes différents, en France dans les Bouches-du-Rhône avec l’ensemble monumental de Fontvieille et en Sardaigne avec notamment la nécropole à domus de janas de S’Elighe Entosu. Ces deux contextes offrent la possibilité d’étudier des hypogées possédant des caractéristiques différentes. La comparaison entre les divers contextes sélectionnés en Méditerranée occidentale permet d’entrevoir les différences et similitudes présentes dans les chaînes opératoires de creusement et les choix effectués par les différents groupes humains. Au-delà de la connaissance des techniques employées pour le creusement de ces architectures, cette étude permet également de s’interroger sur le rôle de celles-ci au sein de la communauté par l’investissement que leur mise en place engendre. / At the end of Prehistory in the Western Mediterranean, the rock-cut tombs are a privileged type of architecture. The understanding of the hypogea’s digging process is essential In order to determine which techniques and strategies come into play in the establishment of these structures. In the context of a PhD research work, a method has been developed on the subject. It is presented in three lines of reflection: the technological study of digging macro-tools, the analysis of the traces which are present on the walls of hypogea using photogrammetry, and an experimentation to confirm or refute the assumptions made during the first two axes of the study. These three axes were developed in different contexts, the monumental context of Fontvieille, located in the geographical area of the Bouches-du-Rhône administrative department in France and the necropolis of S'Elighe Entosu in Sardinia, Italy. These two fieldworks allows us to study the different characteristics of the hypogea. The comparison between the various contexts selected in the western Mediterranean allows us to glimpse the differences and similarities present in the digging process chains and the choices made by the different human groups. Beyond the knowledge of the techniques used for the digging of these architectures, this study also makes it possible to question the role of these in the community by the investment that their establishment generates.

A large proportion of the farming in Kenya and Eastern Africa is performed by smallholding farmers. At the same time, consumers are expecting to find foodstuff more close by and in a more convenient way than most smallholding farmers can provide. Crowdsourcing can efficiently be applied to many problems where many small producers need to collaborate to create the complete product, without exposing much of the complex process to the end consumers. Using semi structured interviews, systematic literature review and prototyping, the application of crowdsourcing to reach and empower smallholding farmers was explored. The findings were used to create recommendations in the form of guidelines that are expected to serve as ground work and background to future studies within the area. In general, a mobile based platform for crowdsourcing was found to be viable while still having some problems with the intended target market. Three primary factors which affects the potential success were identified; The generally low availability of internet to smallholding farmers (limited by high prices), lacking education which can limit comprehension of more complicated processes, and smartphones with limited capacity for advanced applications. / En stor del av jordbruket i Kenya och östra Afrika utförs av småbönder. Samtidigt förväntar sig konsumenter att kunna hitta matprodukter närmare och på ett mer bekvämt sätt än de flesta småbönder kan erbjuda. Crowdsourcing kan effektivt tillämpas på många problem där flera små producenter behöver samarbeta för att skapa den kompletta produkten utan att utsätta slutkonsumenten för den komplexa processen. Med hjälp av semi-trukturerade intervjuer, systematisk litteratur studie och prototyping, undersöktes tillämpningen av crowdsourcing för att nå och förstärka småbönder. Resultaten användes för att skapa rekommendationer i form av riktlinjer som förväntas fungera som grundarbete och bakgrund till framtida studier inom området. I allmänhet visade sig en mobilbaserad plattform för crowdsourcing vara realistisk, samtidigt som den fortfarande hade några problem med den avsedda målmarknaden. Tre primära faktorer som påverkar den potentiella framgången identifierades. Dessa var den generellt låga tillgängligheten av internet till småbönder (begränsad av höga priser), avsaknad av utbildning som kan begränsa förståelsen av mer komplicerade processer, och smartphones med begränsad kapacitet för avancerade applikationer.