O rio Paraíba do Sul, em seu trecho paulista, é sem dúvida um dos mais importantes cursos d\'água do Estado de São Paulo. Foi às suas margens que parte do desenvolvimento do Brasil ocorreu, em virtude do plantio do café, e como ligação entre as duas principais cidades do país; São Paulo e Rio de Janeiro, rota conhecida como macro-eixo. As descargas de efluentes líquidos domésticos, sem o devido tratamento, são hoje as fontes que mais poluem o rio. Este estudo pretende avaliar a evolução da carga orgânica de origem doméstica, lançada pelos municípios que compõem a bacia hidrográfica, até os limites do Estado de São Paulo com o Estado do Rio de Janeiro. O período escolhido para a realização da avaliação foi de uma década, entre os anos de 1998 a 2007, já que, o início das atividades do Comitê da Bacia do rio Paraíba do Sul no âmbito do Estado de São Paulo, ter sido no ano de 1994. Os parâmetros químicos definidos para a realização do estudo, a partir dos 16 pontos de monitoramento da água da CETESB (Companhia de Tecnologia e Saneamento Ambiental), localizados ao longo do curso do rio, no trecho paulista, foram: a DBO (demanda bioquímica de oxigênio) e o OD (oxigênio dissolvido), que representam o nível de poluição orgânica de origem doméstica em um corpo d\'água, conforme estabelece as legislações vigentes para a bacia hidrográfica do rio Paraíba do Sul. A importância deste estudo está relacionada com as condições em que as águas do rio Paraíba do Sul, entram na represa do Funil, no Estado do Rio de Janeiro, que tem reclamado muito da poluição do rio no trecho paulista, por ser este o manancial mais importante para o abastecimento da região metropolitana do Rio de Janeiro. Entende-se, portanto a preocupação daquele Estado com a qualidade da água do rio à montante da represa do Funil. / The Paraíba do Sul rives, at São Paulo, is undoubtedly one of the most important water courses of the State of São Paulo. Went to their banks that the development of Brazil occurred because of the planting of coffee, and as a liaison between the two main cities of Brazil, São Paulo and Rio de Janeiro, route known as \"macro-axis.\" Discharges of liquid household, without proper treatment, are now the sources that pollute the river more. This study aims to assess the evolution of the organic load of domestic origin, launched by the municipalities that make up the basin, until the limits of the State of São Paulo with the State of Rio de Janeiro. The period chosen for the evaluation was a decade between the years 1998 to 2007, since the beginning of activities of the Committee of the basin of the river Paraíba do Sul in the state of São Paulo, was the year 1994. The chemical parameters defined for the study, from 16 points to monitor the water CETESB (Cia. of Thecnology e Wasting Envoriomental), located along the course of the river, in São Paulo words, were the BOD (biochemical demand of oxygen) and DO (dissolved oxygen), representing the level of organic pollution of domestic origin in a body of water, as provides the existing laws for the basin of the river Paraíba do Sul The importance of this study is related to the conditions under which the waters of the river Paraíba do Sul, the funnel into the reservoir in the state of Rio de Janeiro, which has claimed much of the pollution of the river stretch in Sao Paulo, since this is the most wealth important for the supply of the metropolitan region of Rio de Janeiro. It is understood, therefore the concern that state with the water quality of the river upstream to the dam of the funnel.

The purpose of this thesis work was to make a survey of current on-line payment technologies and find out which are they and how do they work? Compare and analyze them from a security point of view, as well as a usability point of view. What is good? What is bad? What is lacking? To achieve this purpose, an overview of the current on-line payment technologies was acquired through academic books and papers, Internet sites, magazines. Basic cryptographic and security related techniques were studied for the security analysis of current on-line payment systems. In this work, various current on-line payment systems were classified into two groups [Macro and Micro on-line payment systems]. This classification was based on the mode of on-line payment transactions. To analyze these on-line payment systems, a set of payment system requirements were formed [Security Issues, Usability Issues, Anonymity, Scalability etc]. Under the category of Macro payment system, Credit Card payment system, Debit Card payment system, Stored Value Card payment system, Electronic Check payment system, Electronic Cash payment system, Electronic account transfer payment system and mobile payment system transactions were examined. Under the category of Micro payment system, Hash Chain based Payment System, Hash Collisions and Hash sequences based Payment Systems, Shared Secrete Keys based Payment Systems and Probability based payment systems were examined. Based on the requirements of payment system, these on-line payment systems were analyzed and compared. In the analysis phase, the advantages and drawbacks of these payment systems were figured out. It was found from the study that the credit card based payment systems are the most widely used means of conducting on-line payments. It is evident that credit card based payment systems satisfy stakeholder requirements the best, as they offer more flexible payment options, having a large user-base, benefit from familiarity and simplicity of use and also allow international payments. The other on-line payment systems lack this flexibility It can also be extracted from the study that users want more simplified, convenient and secure on-line payment systems. Thus the futuristic on-line payment systems will have all secure payment options into one system.

Pour beaucoup de cultures, un sol non travaillé est une alternative de plus en plus crédible au travail intensif du sol, en particulier pour des raisons environnementales. Mais l’ananas (ananas comosus) présente un enracinement fragile très sensible à la structure, ce qui motive souvent un travail important du sol avant plantation. L’alternative d’une plantation sans travail du sol ne va donc pas de soi. L’objet de cette thèse est de répondre à la question de la faisabilité d’une culture d’ananas sans travail du sol, en remplaçant ce dernier par une plante de service « décompactante » dont les traits racinaires seraient favorables à la (re)structuration d’un sol compact. Le travail de cette thèse a donc porté sur l’évaluation de plusieurs espèces candidates, puis sur l’étude, au champ, des effets sur le sol de la plus prometteuse (Stylosanthes guianensis ). Enfin, dans le cadre d’un essai au champ comparant un système de culture innovant ananas sans travail du sol, on a étudié l’effet de la plante de service sur le fonctionnement de la culture de l’ananas. Dans un premier essai, c’est le Stylosanthes guianensis qui, comparé à huit autres espèces (Arachis pintoï, Brachiaria decumbens, Cajanus cajan, Crotalaria juncea, Cynodon dactylon, Eleusine coracana, Pueraria phaseoloides, et le maïs), a montré les traits racinaires les plus favorables à la structuration d’un sol compact. Les valeurs supérieures du diamètre racinaire moyen et de la densité de longueur racinaire (DRL) caractérisent les principaux traits impliqués. Dans un deuxième essai, les mesures de conductivité hydraulique, d’indice des vides du sol et d’analyse d’images de blocs de sol imprégné sur la répartition surfacique des différents types de porosité ont montré que la culture du Stylosanthes guianensis avait augmenté l’indice des vides du sol et provoqué l’apparition d’une porosité fissurale de grande taille, contribuant ainsi à l’amélioration de la structure du sol. Enfin, un troisième essai mettant en comparaison (i) un système de culture innovant où la culture d’ananas est implantée sans travail du sol après une culture de S. guianensis restructurante et (ii) un système conventionnel comportant un travail profond du sol (et pas de plante de service) a montré que le rendement en fruit est similaire dans les deux systèmes. Cet essai a permis de vérifier que l’enracinement de l’ananas en condition de sol non travaillé bénéficiait du précédent S. guianensis. / For many crops, direct drilling is a well-tried alternative facing the damaging effects of intensive tillage, mainly for environmental causes. But, pineapple (ananas comosus), presents a fragile rooting system which is very sensitive to soil structure. This leads frequently to intensive soil tillage before planting. Direct drilling is not so evident. The aim of this thesis is to give an answer to the feasibility of a no till system for pineapple cultivation, by using a plant with favorable roots traits for compacted soil (re)structuration. This work consisted in evaluating several candidate species, followed by the study, on the field, of the effects the most promising on soil (Stylosanthes guianensis). Finally, through a field experiment, comparing an innovating no till pineapple cultivation system we studied the use effects of Stylosanthes guianensis on the pineapple crop functioning. In a first experiment, Stylosanthes guianensis compared with eight other species (Arachis pintoï, Brachiaria decumbens, Cajanus cajan, Crotalaria juncea, Cynodon dactylon, Eleusine coracana, Pueraria phaseoloides and corn) showed better roots traits for structuring a compacted soil. Measures of average root diameter and root length density are the main implicated roots traits. In a second experiment, the measures of hydraulic conductivity, of the soil void ratio and the analysis of blocks of resin-impregnated soil on the surface distribution of the different type of porosity, all of this showed that Stylosanthes guianensis had increased the soil void ratio and had caused the creation of large-sized cracked porosity, thus contributing to the improvement of the soil structure. Finally, a third experiment involving a comparison between (i) an innovating cultivation system where pineapple is growing in a no till soil after a structuring crop of S. guianensis and (ii) a conventional system with deep tillage (without structuring crop), showed similar fruit yield. This experiment showed evidence that the rooting of pineapple in no till soil benefited from the previous Stylosanthes.

Please read the abstract in the section 00front of this document / Thesis (D Com (Econometrics))--University of Pretoria, 2007. / Economics / unrestricted

Cette étude porte sur la production des bio-huiles à partir de la pyrolyse de bois de hêtre et celui du pin représentant respectivement les bois durs et les bois tendres. Afin de répondre à la problématique liée à la séparation des composés chimique de valeur ajoutée de la bio-huile,une étude a été effectuée sur la faisabilité d’une pré-séparation des constituants chimiques de la bio-huile à l’aide d’une pyrolyse étagée en température dans un réacteur en lit fixe de sorte à cibler la thermo-décomposition sélective des macro-composants de la biomasse (hémicellulose, cellulose et lignine). L’identification du couple macro-composant – marqueur de la décomposition est réalisée à partir du bilan en macro-composant dans le solide résiduel et l’identification par GC/MS des constituants contenus dans la bio-huile produite. Les résultats de cette partie ont montré la possibilité de la pré-séparation des fractions de dérivés de furane et des produits phénoliques, cependant le gain en sélectivité se fait au détriment du rendement total de la bio-huile. La deuxième partie de ce travail concerne l’étude de la production de la bio-huile dans les conditions de pyrolyse rapide dans un réacteur gaz/solide.Afin d’établir une relation entre les conditions opératoires de pyrolyse et la composition des bio-huiles, un outil permettant la comparaison pertinente des testes expérimentaux a été élaboré. Les expériences ont montré que le rendement de et la composition de l’huile de pyrolyse dépend essentiellement de : la nature du bois, la vitesse de chauffe et le temps de séjours effectif des particules de bois dans le réacteur. / This research study is concerned in the production of bio-oils from the pyrolysis of beech and pines wood representing the hard and soft wood, respectively. In order to resolve the problems related to the separation of high added value molecules from the bio-oil, a study was held out on the feasibility of the pre-separation of the chemical components of bio-oil using of a staged pyrolysis temperature in a fixed bed reactor in order to target selective thermal decomposition of macro-components of biomass (hemicellulose, cellulose and lignin). The identification of macro-component couples - marker of decomposition is made from the balance macro-component in the residual solid and identification by GC / MS of the chemical components contained in the produced bio-oil. The results of this part have shown the possibility of the pre-separation of furans and phenolic derivatives, despite of the gain in selectivity at the expense of overall yield of bio-oil. The second part of this work (concerns with the study of the production of bio-oil in fast pyrolysis conditions in a gas / solid reactor. To establish a relationship between the operating conditions and chemical composition of pyrolysis bio-oil, a tool for meaningfull comparison of experiments was developed. Experiments have shown that the yield and composition of pyrolysis oil depends mainly on the composition of wood, the heating rate and the effective residence time of the wood particles into the reactor.

In this dissertation, the art of the short story as practised by S.N. Nkadimeng (Mmantshaotlogele) is investigated in accordance with the narratological descriptive model. According to this approach the literary work is divided into three levels, namely, content level, plot level and style level. The level of style, however, is not discussed in detail in this dissertation. In this study, Nkadimeng's art is placed within the framework of a brief discussion of the Northem Sotho short story as an art form. Furthermore, the aim of this investigation is formulated. Thereafter the relevant concepts which are discussed in this dissertation are also illustrated. In the second, third and fourth chapters attention is paid mainly to the analysis of a single short story, that is 0 nyalwa lenyalo mang .. . ; however, the other short stories in this collection, among others Nna nka se je dipute and Thapelo ya pula are referred to as examples. In the last chapter, Nkadimeng's work, particularly with regard to his ironic stories, is compared to Mpepele's and Matsepe's work. Nkadimeng writes with compassion about his people; his irony is delicate and mocking without venom, which differs from that of Matsepe and Mpepele. Whereas Matsepe mocks important figures in the society, such as leaders, kings, the rich and so forth, Nkadimeng's and Mpepele's mocking is aimed at the weaknesses of the ordinary people. / Dissertation (MA)--University of Pretoria, 2012. / Philosophy / unrestricted

Advanced composite materials have enabled the conventional aircraft structures to reduce weight, improve fuel efficiency and offer superior mechanical properties. In the past, materials such as aluminum, steel or titanium have been used to manufacture aircraft structures for support of heavy loads. Within the last decade or so, demand for advanced composite materials have been emerging that offer significant advantages over the traditional metallic materials. Of particular interest in the recent years, there has been an upsurge in scientific significance in the usage of adhesively bonded composite joints (ABCJ’s). ABCJ’s negate the introduction of stress risers that are associated with riveting or other classical techniques. In today’s aircraft transportation market, there is a push to increase structural efficiency by promoting adhesive bonding to primary joining of aircraft structures. This research is focused on the issues associated with the durability and related failures in bonded composite joints that continue to be a critical hindrance to the universal acceptance of ABCJ’s. Of particular interest are the short term strength, contamination and long term durability of ABCJ’s. One of the factors that influence bond performance is contamination and in this study the influence of contamination on composite-adhesive bond quality was investigated through the development of a repeatable and scalable surface contamination procedure. Results showed an increase in the contaminant coverage area decreases the overall bond strength significantly. A direct correlation between the contaminant coverage area and the fracture toughness of the bonded joint was established. Another factor that influences bond performance during an aircraft’s service life is its long term strength upon exposure to harsh environmental conditions or when subjected to severe mechanical loading. A test procedure was successfully developed in order to evaluate durability of ABCJ’s comprising severe environmental conditioning, fatiguing in ambient air and a combination of both. The bonds produced were durable enough to sustain the tests cases mentioned above when conditioned for 8 weeks and did not experience any loss in strength. Specimens that were aged for 80 weeks showed a degradation of 10% in their fracture toughness when compared to their baseline datasets. The effect of various exposure times needs to be further evaluated to establish the relationship of durability that is associated with the fracture toughness of ABCJ’s.

Un ensemble de disciplines tente de comprendre les causes de la distribution de la biodiversité à la surface de la terre. Cette thèse, à l'interface entre macro-écologie et phylogéographie, démêle le rôle relatif des différents facteurs environnementaux et des processus contrôlant la diversité des crustacés aquatiques souterrains en Europe. L'utilisation d'un modèle biologique souterrain permet d'écarter l'effet de la saisonnalité thermique, omniprésente dans les milieux de surface. L'action de multiples facteurs – plus particulièrement la disponibilité des ressources trophiques et l'hétérogénéité environnementale – et les variations régionales de leur importance relative fournissent l'explication la plus parcimonieuse des patrons de richesse. Ce résultat s'oppose au paradigme du rôle prépondérant du processus d'extinction causé par les fortes oscillations climatiques du Pléistocène en Europe du nord. Toutefois, ces oscillations ont très probablement sélectionné des organismes mobiles qui participent à l'augmentation de la taille moyenne des aires de répartition des espèces avec la latitude. La reconstruction de la dynamique des aires de distribution montre que la dispersion est un processus très hétérogène entre et au sein des espèces. Elle interviendrait lors de courtes fenêtres temporelles entre lesquelles l'adaptation locale tendrait au contraire, à contrecarrer les capacités de dispersion. Enfin, ce travail propose des pistes de réflexion afin d'expliquer plus précisément, à partir de données moléculaires supplémentaires et d'outils génomiques, les variations géographiques des taux de diversification et de substitution à l'échelle continentale / A set of disciplines attempt to understand causes of biodiversity patterns on the earth. This thesis, at the frontier between macroecology and phylogeography, disentangles the relative influence of environmental factors and processes shaping groundwater crustacean diversity in Europe. Groundwater habitats offer useful case studies for avoiding the effect of thermal seasonality, which is pervasive in surface ecosystems. The influence of multiple factors – especially productive energy and spatial heterogeneity – and regional variation in their relative importance provide the most parsimonious explanation of species richness patterns. This result undermines the prominent role attributed to the disproportionate extinction of species in northern European regions with high historical climate oscillations. However, these oscillations have probably selected vagile species which contribute to the increase in median range size of species with latitude. Reconstructing range dynamics shows that dispersal is a heterogeneous process within and among species. It may occur during short time windows between which local adaptation favors specialization. Finally, I suggest several research avenues using molecular data and genomic tools for understanding geographical variation in diversification and substitution rates at continental scale

Cette thèse s'inscrit dans le cadre de l'élaboration de méthodes simplifiées d'analyse du comportement non-linéaire des ouvrages en béton armé à voiles porteurs sous action sismique. Une stratégie de modélisation simplifiée basée sur la notion de macro-éléments a été adoptée, afin de décrire le comportement non-linéaire du mur voile et d'estimer sa capacité résistante vis-à-vis des forces latérales. Les lois de comportement utilisées pour le béton et l'acier sont basées sur la théorie de l'endommagement et de la plasticité. La validation des capacités prédictives du modèle à partir des résultats expérimentaux a été aussi effectuée. De plus, une étude paramétrique a été réalisée pour étudier la sensibilité des résultats aux variations des paramètres liés au modèle, au matériau et/ou type de chargement. / Abstract

Dans le domaine de l’électronique organique comprenant les cellules photovoltaïques (OPV), les diodes électroluminescentes (OLED) et les transistors à effet de champ (OFET), l’intérêt pour des matériaux ambipolaires a fortement augmenté au cours de ces dernières années.Dans ce contexte, nous nous sommes intéressés au cours de cette thèse au design et à la préparation de différentes architectures semi-conductrices auto-organisées avec lesquelles il serait possible d’injecter et de transporter à la fois les trous et les électrons. Notre approche est basée sur des matériaux cristaux liquide (LC) incorporant différents types de systèmes électron-donneurs (p-type) ou électron-accepteurs (n-type) dans une architecture moléculaire ou macromoléculaire unique. Ainsi, nous avons synthétisé et caractérisé différentes séries de semi-conducteurs organiques tels que des diades discotiques LC donneur-σ-accepteur, des diades calamitiques LC donneur-σ-accepteur, et des polymères en peigne LC donneur-σ-accepteur portant des groupements latéraux discotiques. Leurs comportement thermiques, leurs propriétés optiques et électroniques, leurs propriétés d’auto-organisation en volume et en film mince, ainsi que leurs propriétés de transport de charge sont présentées et discutés.Ces études ont montré que tous ces matériaux présentent des propriétés liquide-cristallines en s’auto-organisant selon différentes structures telles que des organisations colonnaires, lamellaires et lamello-colonnaires. Plus particulièrement, ces matériaux montrent une nano-ségrégation spontanée en volume des fragments de type p et de type n, formant des chemins bien distincts pour chaque type de porteurs de charge, ces résultats étant bien mis en évidence par les premières mesures de transport de charge ambipolaire observées par temps de vol et en configuration transistor à effet de champs. / In the general field of organic electronics, including Organic Photovoltaic (OPV), Organic Light-Emitting Diode (OLED) and Organic Field-Effect Transistor (OFET), the interest for the ambipolar organic materials have increased remarkably during the recent years.In this context, we were interested, in this present work, in designing and preparing different new self-organized semiconducting architectures in which it could be possible to inject and transport both holes and electrons. Our approach is based on liquid crystalline (LC) materials incorporating different kinds of electron-donor (p-type) and electron acceptor (n-type) π-conjugated systems in a unique molecular or macromolecular architecture. Thus, we synthesized and characterized different series of organic semiconductors such as donor-σ-acceptor discotic LC dyads and triads, donor-σ-acceptor calamitic LC dyads, and donor-σ-acceptor side-chain LC polymers bearing discotic side-groups. Their thermal behaviors, optical and electronic properties, self-organization properties both in bulk and in thin films, and finally charge transport properties are presented and discussed.Based on different characterization techniques, we demonstrated that all these series of materials present liquid crystalline properties in self-organizing in different structure such as columnar, lamellar, and lamella-columnar organizations. More particularly, these materials exhibit spontaneous nanosegregation of p-type and n-type entities in bulk, leading to well defined distinct conductive channels for each type of charge carriers as evidenced by the preliminary ambipolar charge transport properties observed by Time-of-flight and Field effect transistor measurements.