The interaction of a liquid drop with a solid surface is being actively studied to understand practically encountered scenarios such as the impact of fuel spray droplets onto the walls of engine combustion chamber, the formation of thermal barrier coating on the surfaces of turbine blades, the process of ink-jet printing, etc. The surface topography of solid surface is one of the major parameters influencing the dynamics of drop-surface interaction process. Understanding the precise role of surface topography features such as micro asperities and grooves on the spreading and receding processes of impacting liquid drops is crucial for the improvement in abovementioned applications. Recent developments in the fabrication of micro- and nano-structures on solid surfaces provide fabulous opportunities to investigate the role of single/multiple micro asperities and grooves on the dynamics of impacting drops. The thesis deals with an experimental work on the impact of water drops on stainless steel surfaces comprising unidirectional parallel grooves. A group of six target grooved surfaces covering a wide range of surface wettability were considered. The target surfaces were prepared using the techniques of photolithography, electro discharge machining, and laser machining. Scanning electron microscope and optical surface profilometer were used to characterize the groove texture geometrical parameters of the target grooved surfaces. The experiments of drop impact were carried out in an experimental apparatus consisting of a liquid drop generator, a substrate table, and a digital video imaging system. Free-falling distilled water drops released from a certain height were allowed to impact normally on the target surfaces. The image sequences of drop impact dynamics were constructed from the images captured using the digital video imaging system. Majority of the drop impact experiments were captured using a high speed video camera operating with frame speed ranging from 3000 to 10000 fps. For the target grooved surfaces, the impact dynamics was analyzed for the impacting drop liquid oriented both in the direction perpendicular to the grooves ( ) and in the direction parallel to the grooves (||) via independent test runs. The captured digital frames were used to deduce the temporal variation of impacting drop parameters such as drop contact diameter, drop contact angle, and drop height at the center of impacting drop with the aid of image processing software. The impacting drops were characterized in terms of Weber number, We expressed in terms of drop impact velocity and drop diameter measured just before the start of impact process. The study covered We ranging from 1.8 to 170. In general, the groove texture on the solid surface influences the drop impact process for all We examined in the study. The effect is more pronounced for the receding of impacting drops. For high We drops, the groove texture enhances the perturbations seen at the periphery of spreading lamella. The study showed quantitatively that the drop impact process on a target grooved surface comprising unidirectional parallel grooves develops a non-axisymmetric drop flow on the grooved surface exhibiting different spreading and receding processes of impacting drop liquid in the directions perpendicular ( ) and parallel (||) to the grooves. The maximum spreading diameter reached immediately after the completion of early inertia-dominated spreading in is less than that obtained in || due to the loss of drop kinetic energy caused by the pinned motion of drop liquid in . The non- axisymmetric drop flow on the target grooved surface develops a difference between the frequencies of contact angle oscillation of impacting drop liquid in  and ||. The frequency difference in contact angle oscillation causes the beating phenomenon in the temporal variation of the contact angle anisotropy, Δθ and drop height at the center of impacting drop, Z. For a given target grooved surface, the experimental measurements suggested that the beat frequency is almost independent of We. The temporal variation of Δθ and Z do not show the traces of beating phenomenon for the impact of high We drops. Owing to the non-axisymmetric drop flow, the final equilibrium drop shape is eccentric for the impact of low We drops and approaches a circular shape for the impact of high We drops. The role of groove texture geometrical parameters is seen in the drop impact process via the surface wettability especially for the impact of low We drops. Larger surface roughness factor makes the target grooved surface to exhibit hydrophobic characteristics.

Cette thèse apporte des contributions à la modélisation, compréhension ainsi qu'à la communication efficace d'information dans les réseaux dynamiques peuplant la périphérie de l'Internet. Par réseaux dynamiques, nous signifions les réseaux pouvant être modélisés par des graphes dynamiques dans lesquels noeuds et liens évoluent temporellement. Dans la première partie de la thèse, nous proposons un nouveau modèle de mobilité - STEPS - qui permet de capturer un large spectre de comportement de mobilité humains. STEPS mets en oeuvre deux principes fondamentaux de la mobilité humaine : l'attachement préférentiel à une zone de prédilection et l'attraction vers une zone de prédilection. Nous proposons une modélisation markovienne de ce modèle de mobilité. Nous montrons que ce simple modèle paramétrique est capable de capturer les caractéristiques statistiques saillantes de la mobilité humaine comme la distribution des temps d'inter-contacts et de contacts. Dans la deuxième partie, en utilisant STEPS, nous analysons les propriétés comportementales et structurelles fondamentales des réseaux opportunistes. Nous redéfinissons dans le contexte des réseaux dynamiques la notion de structure petit monde et montrons comment une telle structure peut émerger. En particulier, nous montrons que les noeuds fortement dynamiques peuvent jouer le rôle de ponts entre les composants déconnectés, aident à réduire significativement la longueur du chemin caractéristique du réseau et contribuent à l'émergence du phénomène petit-monde dans les réseaux dynamiques. Nous proposons une façon de modéliser ce phénomène sous STEPS. À partir d'un réseau dynamique régulier dans lequel les noeuds limitent leur mobilité à leurs zones préférentielles respectives. Nous recablons ce réseau en injectant progressivement des noeuds nomades se déplaçant entre plusieurs zones. Nous montrons que le pourcentage de tels nœuds nomades est de 10%, le réseau possède une structure petit monde avec un fort taux de clusterisation et un faible longueur du chemin caractéristique. La troisième contribution de cette thèse porte sur l'étude de l'impact du désordre et de l'irrégularité des contacts sur la capacité de communication d'un réseau dynamique. Nous analysons le degré de désordre de réseaux opportunistes réels et montrons que si exploité correctement, celui-ci peut améliorer significativement les performances du routage. Nous introduisons ensuite un modèle permettant de capturer le niveau de désordre d'un réseau dynamique. Nous proposons deux algorithmes simples et efficaces qui exploitent la structure temporelle d'un réseau dynamique pour délivrer les messages avec un bon compromis entre l'usage des ressources et les performances. Les résultats de simulations et analytiques montrent que ce type d'algorithme est plus performant que les approches classiques. Nous mettons également en évidence aussi la structure de réseau pour laquelle ce type d'algorithme atteint ses performances optimum. Basé sur ce résultat théorique nous proposons un nouveau protocole de routage efficace pour les réseaux opportunistes centré sur le contenu. Dans ce protocole, les noeuds maintiennent, via leurs contacts opportunistes, une fonction d'utilité qui résume leur proximité spatio-temporelle par rapport aux autres noeuds. En conséquence, router dans un tel contexte se résume à suivre le gradient de plus grande pente conduisant vers le noeud destination. Cette propriété induit un algorithme de routage simple et efficace qui peut être utilisé aussi bien dans un contexte d'adressage IP que de réseau centré sur les contenus. Les résultats de simulation montrent que ce protocole superforme les protocoles de routage classiques déjà définis pour les réseaux opportunistes. La dernière contribution de cette thèse consiste à mettre en évidence une application potentielle des réseaux dynamiques dans le contexte du " mobile cloud computing ". En utilisant les techniques d'optimisation particulaires, nous montrons que la mobilité peut augmenter considérablement la capacité de calcul des réseaux dynamiques. De plus, nous montrons que la structure dynamique du réseau a un fort impact sur sa capacité de calcul.

Icicles are a ubiquitous and picturesque feature of cold winter weather. Their familiar form emerges from a subtle interplay between the solidification dynamics of ice and the gravity-driven flow of the thin water film flowing over their evolving surface. The latent heat released by freezing is advected by the water film and ultimately carried away by the surrounding sub-zero air, which is also flowing. Like many processes far from equilibrium, icicle growth can exhibit nonlinear pattern formation. While scaling theory predicts that icicles converge to `platonic', self-similar shapes, natural icicles often exhibit regular ripple patterns about their circumference, which are due to a morphological instability. This thesis presents a comprehensive experimental study of icicles that sheds new light on the dynamics of their growth and the origin of their form. A table-top apparatus was designed and built for the controlled growth of icicles, under different conditions of temperature, water supply rate, ambient air motion, and water purity. Image analysis and Fourier methods were used to examine their morphology. Contrary to theoretical expectations, ripples do not appear on icicles made from pure water. Instead, ripples grow and travel on icicles made from salt solutions, even at very low concentrations. The addition of non-ionic surfactant or dissolved gases does not produce ripples, unless ionic impurities are also present. The ripple wavelength is independent of time and growth conditions. The ripple amplification rate and traveling velocity vary weakly with the ionic concentration, as do the tip and radial growth speeds of the icicle. While the tip and radial growth also depend on the ambient temperature and input mass flux, the ripple dynamics is not correlated with extrinsic conditions. If the ambient temperature or input mass flux is sufficiently low, the tip growth only advances for a short period of time before it ceases. After cessation, the shape of the icicle deviates increasingly from self-similarity. The most self-similar icicles are made from pure water with the surrounding air gently stirred, whereas icicles made from impure water in still air tend to grow multiple tips.

Transformer ageing is inevitable and it is a challenge for utilities to manage a large fleet of ageing transformers. This means the need for monitoring transformer condition. One of the most widely used methods is oil sampling and testing. Databases of oil test records hence manifest as a great source of information for facilitating transformer ageing assessment and asset management. In this work, databases from three UK utilities including about 4,600 transformers and 65,000 oil test entries were processed, cleaned and analysed. The procedures used could help asset managers in how to approach databases, such as the need for addressing oil contamination, measurement procedure change and oil treatment discontinuities. An early degradation phenomenon was detected in multiple databases/utilities, which was investigated and found to be caused by the adoption of hydrotreatment oil refining technique in the late 1980s. Asset managers may need to monitor more frequently the affected units and restructure long term plans. The work subsequently focused on population analyses which indicated higher voltage transformers (275 kV and 400 kV) are tested more frequently and for more parameters compared with lower voltage units (33 kV and 132 kV). Acidity is the parameter that shows the highest correlation with transformer in-service age. In addition, the influence of the length of oil test records on population ageing trends was studied. It is found that it is possible to have a representative population ageing trend even with a short period (e.g. two years) of oil test results if the transformer age profile is representative of the whole transformer population. Leading from population analyses, seasonal influence on moisture was investigated which implies the importance of incorporating oil sampling temperature for better interpretation of moisture as well as indirectly breakdown voltage records. A condition mismatch between dielectric dissipation factor and resistivity was also discovered which could mean the need for revising the current IEC 60422 oil maintenance guide. Finally, insulation condition ranking was performed through principal component analysis (PCA) and analytic hierarchy process (AHP). These two techniques were demonstrated to be not just capable alternatives to traditional empirical formula but also allow fast, objective interpretation in PCA case, as well as flexible and comprehensive (objective and subjective incorporations) analysis in AHP case.

L’accroissement du déplacement des footballeurs professionnels de l’Afrique vers les ligues européennes, observé dès les années 1990, a transformé la migration du travail du football. En retour, cela a aussi eu un impact sur les revenus des footballeurs africains, leur statut social, et leur relation avec leurs communautés d’origine en termes de soutien socioéconomique. Cette recherche se focalise sur ce sujet en s’appuyant sur la compréhension de l’évolution du football professionnel africain, des itinéraires de migration des joueurs, afin d’expliquer le « phénomène de don en retour » (PDR) lié à la relation entretenue avec leurs communautés d’origine. Elle examine le rôle des facteurs économiques et non économiques qui orientent la manière dont les footballeurs africains donnent en retour à leurs familles, leurs proches, leurs communautés. Celui-ci peut être déterminé dans le but d’un retour sur investissement, par l’influence des valeurs communautaires, des normes, par l’intégration à des réseaux sociaux ou des réseaux institutionnalisés relatifs à l’émigration des footballeurs. En d’autres termes, l’analyse de leur don en retour doit être basée sur la combinaison de facteurs sociaux, culturels et économiques. Aussi, cette recherche mobilise une approche interdisciplinaire à partir du modèle théorique d’analyse de la socio-économie. La méthodologie de Weber contribue à le faire, par l’analyse de l’action de don en retour des footballeurs. Celui-ci est généralement considéré comme la contribution sociale des joueurs, et leurs communautés attendent de recevoir quelque chose de la part des joueurs professionnels africains émigrés ayant réussi financièrement. L’étude est basée sur une enquête qualitative auprès de trente-deux footballeurs professionnels africains incluant aussi des biographies et autobiographies d’autres footballeurs africains. Les résultats montrent que les comportements des footballeurs africains migrants, en termes de don en retour, dépendant de leurs justifications qui sont basées sur des logiques d’intérêt économique, social et culturel.La recherche révèle trois résultats majeurs :1) Une évolution spécifique du football africain et de la perception du football professionnel par les communautés. On identifie une périodisation en trois phases, montrant l’évolution des familles, des structures du football et des stratégies de migration : a) une vision controversée du football (années 1980) : football vs scolarisation ; b) une vision partagée du football (années 1990) : passage progressif d’une activité sociale à une activité professionnelle ; et 3) le football professionnel comme opportunité (années 2000).2) Trois types d’itinéraires migratoires de joueurs qui sont liés à leurs stratégies, aux réseaux mobilisés, et aux ressources disponibles : a) ressources collectives, b) réseaux formels, et c) les ressources individuelles.3) Une typologie du « phénomène de don en retour » (PDR) du footballeur africain migrant concernant les comportements socio-économiques : a) familial hybride, b) familial croisé proche, c) familial partagé, d) familial de l’ombre, qui influencent leurs types d’investissements dans les communautés. D’autre part, certains projets de joueurs tendent à soutenir le développement régional et national de leurs communautés. Toutefois, les joueurs migrants africains doivent gérer et protéger leur réputation et leurs ressources sportives en les utilisant intelligemment et en effectuant de bonnes actions pour leurs communautés, amis et autres au-delà du continent. / The increase in movement of professional footballers from Africa to the European leagues as observed since the 1990’, has transformed the labour football migration. In return, this also impacted African footballers’ incomes, social status, and their relation to the communities of origin in terms of socio-economic support. This research focuses on this subject by drawing on the understanding of the evolution of African professional football, players migration itineraries, as to explain the ‘give back phenomenon’ (GBP) related to their relationship with the communities of origin. It examines the role of the economic and non-economic factors that orient African footballers’ ways of giving back to their families, relatives, and the communities. Their give back may be determined by the aim of return on investments, by the influence of communities’ values, norms, or by embeddedness in social networks or by the institutionalised networks related to footballers’ migration. In other words, the analysis of their giving back may be based on the combination of social, cultural and economic factors. Thus, this research mobilised multidisciplinary approach through the socio-economic theoretical model of analysis. Weber methodology helps to do so, in the analysis of footballers’ 'give back' action. This is generally considered as the players’ social contribution and their communities expect to receive something from financially successful professional African migrant players. The study’s qualitative survey was based on thirty-two interviews of professional players from Africa including, biographies and autobiographies. The results show that African migrant players’ behaviours in term of giving back depend on their justifications, which are based on economic interest, social or cultural logics.The research revealed three major outcomes:1) specific evolution of African football and communities’ perception of professional football. This identified one periodization, with three phases, showing families, football structures and migration strategies evolution: a) the controversial vision of football (the 1980s): football vs. school b) the shared vision of football (the 1990s): gradual shift from social activity to a professional activity, and c) football professionalism as an opportunity (the 2000s) 2) three types of players’ migration itineraries which are linked to their strategies, networks mobilised, and the resources available to them: a) collective resource-based, b) formal networks-based, and c) individual resource-based. 3) typology of 'GBP' based on African migrant players’ socio-economic behaviours was a) hybrid family, b) cross-closed family, c) shared family, and d) shadow family that influenced their type of investments in the communities. On another hand, some projects of players tend to support regional and national development in the communities. However, African player migrants have to manage and protect the fame, and sporting resources by using them intelligently to do good things for their communities, friends and others beyond the continent. In conclusion, the itineraries of players’ show the role of the communities in their migration projects. On another hand, the evolution of African football displays how players’ strategies changed with the structuration of African football and the attractiveness of the European football market. The co-determining of economic and non-economic factors relating to the ‘GBP’, justify the use of economic sociology theories. This research demonstrates that ‘GBP’ is not only based on the players’ economic interest but also the combination of social, cultural and economic elements.

Submitted by Noeme Timbo (noeme.timbo@metodista.br) on 2016-09-13T17:02:28Z No. of bitstreams: 1 Jose Antonio.pdf: 1915237 bytes, checksum: 9bb4783cbaeae39698926fc3ec0f7fca (MD5) / Made available in DSpace on 2016-09-13T17:02:28Z (GMT). No. of bitstreams: 1 Jose Antonio.pdf: 1915237 bytes, checksum: 9bb4783cbaeae39698926fc3ec0f7fca (MD5) Previous issue date: 2016-03-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Studying the historical evolution and taking an overview of the religious education in Brazil, we today face the problem of the exclusion of two different types of view on its treatment on public schools: or should it exist the "confessional" religious teaching, or it shouldn't exist at all. Overcoming the view of the laicity as an abstention when affirming that the religious, on its own definition, doesn't concern us nor even the science, and admitting a laicity of intelligence when we defend that is our duty or even the duty of science to understand it as a human and social expression, the teaching of the religious phenomenon can overcome these two views with the use of a strong epistemological basis for this area of knowledge, as fixed in our Constitution. It guarantees the respect to the diversity and the cultural plurality of the brazilian society and it contributes to the comprehension of the religious phenomenon as a "cultural object". It is capable of support practices of a teaching of the religious phenomenon in a secular education system, without prejudicing its laicity - on the contrary, it can actually go on its behalf. The secular education focusing on the formation of a citizen cannot ignore the existance of religions for its strong presence and for its role in a society. It is needed to critically decrypt the religions representations and its practices in name of a more constructive cohabitation between people and extract values from the religious traditions that can contribute with the human life on its plenitude. This model of teaching the religion as an anthropological, social and cultural phenomenon can even perform a specific role on what concerns the knowledge of oneself (identity) and also on what regards the acceptation of the different (alterity), pointing to the construction of ethic values and the notion of being a citizen. This research is based on a great bibliographic raising data and interviews with specialists on secularization, laicity and on religious teaching, all based on Régis Debray's proposal adopted in France. It leads us to conclude that the teaching of the religious phenomenon in Brazil's public schools is not only necessary, but indispensable if we want an education that contributes to the formation of our students in a solidary living. / Ao estudarmos a evolução histórica e o panorama atual do ensino religioso no Brasil, nos deparamos hoje com o problema da exclusão mútua de duas visões do seu tratamento na escola pública: ou deve existir o ensino religioso confessional ou não deve existir nenhum tipo de ensino religioso. Superando uma visão de laicidade de abstenção ao afirmar que o religioso, por definição, não nos diz respeito ou não diz respeito à ciência, e admitindo uma laicidade de inteligência ao defender que é nosso dever ou dever da ciência compreendê-lo como expressão humana e social, o ensino do fenômeno religioso pode superar essas duas visões, a partir de uma base epistemológica sólida para esta área de conhecimento, como já é prevista pela nossa legislação. Ele garante o respeito à diversidade e à pluralidade cultural da sociedade brasileira e contribui para a compreensão do fenômeno religioso como “objeto de cultura”. Ele é capaz de subsidiar práticas de ensino do fenômeno religioso no sistema de ensino laico, sem prejuízo de sua laicidade, mas a favor dela. A educação laica para a cidadania não pode ignorar as religiões pela sua forte presença e função na sociedade. É preciso decodificar criticamente as representações e práticas religiosas em nome da convivência mais construtiva entre as pessoas e extrair das tradições religiosas valores que contribuam para a vida humana na sua plenitude. Este modelo de ensinar a religião como fenômeno antropológico, social e cultural pode ainda cumprir uma função específica no que se refere ao conhecimento de si mesmo (identidade) e do outro para a aceitação do diferente (alteridade) apontando para a construção de valores éticos e de cidadania. Esta pesquisa se baseia em um grande levantamento bibliográfico e entrevistas com especialistas em laicidade e ensino do religioso a partir da proposta de Régis Debray adotada na França. Ela nos leva a concluir que o ensino do fenômeno religioso na escola pública do Brasil não é apenas necessário, mas até indispensável, se queremos uma educação que contribua para a formação dos nossos alunos e alunas para a convivência solidária.

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[pt] Sistemas rotativos atuados através de um eixo flexível apresentam um grande desafio para estratégias de controle, uma vez que o atuador não está conectado diretamente ao sistema principal, causando efeitos de propagação de ondas e acúmulos e dissipações de energia no eixo. Este trabalho apresenta um estudo sobre uma das mais notórias aplicações deste problema, sistemas de perfuração de petróleo. Habitualmente, o sistema de perfuração é composto por um motor de topo conectado à broca através de milhares de metros de tubos de aço que transmitem o toque. Diversos tipos de vibrações podem ser observadas: Axiais, de flexão e torcionais, estas últimas ligadas ao fenomeno stick-slip. Para um completo conhecimento do problema, é necessário conhecer cada uma delas. Esta tese trata especificamente das vibrações torsionais através de uma análise com dois diferentes modelos, um primeiro mais simples de fois graus de liberdade (inércia, mola torcional, amortecedor), e um segundo mais completo discretizado em 20 graus de liberdade capaz de considerar a masssa do eixo e efeitos de propagação de ondas mecânicas no eixo. Este trabalho inclui aidna a construção de uma bancada em escala reduzida para observar os fenômenos associados as vibraçoes torcionais. São apresentados ainda estudos numéricos e experimentais de técnicas de controle de minimizar os efeitos do atrito na dinâmica torcional do sistema. Duas estrututas de controle são estudadas nesta tese a fim de reduzir vibrações torcionais em colunas de perfuração. A primeira é um controle simples, de malha aberta, baseado no comportamento do sistema. A segunda é o controle adaptativo L1, que faz uso de um modelo de refeência do sistema em sua estrutura. / [en] Systems actuated trough a highly flexible shaft poses a big challenge to control strategies as the actuator is not connected directly to the end effector, causing propagation effects as well as an energy accumulation and dissipation in the shaft. This thesis focuses the study of one of the most investigated application of this type, the top driven drilling system used in the oil and gas industry. Usually, the drilling system is composed by a top drive linked to the drill bit trough hundreds or even thousands of meters of steel pipes. All kind of vibrations will be found: longitudinal deformations will be associated to the bit bouncing, flexional with rubbing, and torsional with stick-slip effects. A better understanding is only possible when each of these situations is carefully investigated. This thesis focuses on the torsional deformation of the highly flexible string and presents two different models for the drill string, the first is the most common single spring single damper model. The second one is a 20 DOF Lumped parameters that has the advantage of being able to consider the mass of the drill string and propagation of torsional waves in the shaft. The investigation includes the development of a test rig adequate for torsional vibrations under damping that may induce stick-slip in the system. Two control techniques are studied to reduce the torsional vibrations in drill strings with numerical and experimental results presented. The first is a behavior based open loop scheme control, which is very simple and effective to reduce stick-slip oscillations. The second one is the L1 adaptive control that uses a reference model on its structure.

Resume: The work has a special theme of social accents of the prophets in the period before the exile. There is question what the chronology of the history of the royal era, in which the prophets spoke, was, what social processes were taking place at that time and how they are documented by biblical history and archeology. The first part of the work describes the historical situation in which these prophets were spreading their message. In this epoch the King's time was at the top of its peak, after which the crisis of transition from tribal society started into the urban civilization started which was finished by Israel's exile to Assyria and Judea in Babylon. In the northern empire peaks of the prosperity are considered to be the period during the reign of Achab and Jeroboam II. In the southern Empire it is the Uzziah's period. These peak times of prosperity, stemming from the state development, successful battles, and foreign trade, brought with an increase in social inequality and damage to social relations. The work depicts this time according to biblical sources, particulary the 1st and 2nd Books of Kings and the 2nd Paralipomenon. This section is followed by a chapter on interpretations by which Biblical archeology interprets archeological finds related to the time of the kingdom, especially from the...

This study focuses on the induction of novice teachers in Community Junior Secondary Schools (CJSS) in Gaborone, Botswana. The point of departure is that induction is an important factor that is essential to the success of every beginner teacher. It is the responsibility of the school management to provide comprehensive induction programmes that will support beginner teachers and retain them in the teaching profession. This problem was investigated by means of a literature study and an empirical investigation using a qualitative approach. A small sample of beginner teachers in six selected schools in Gaborone formed the sample for this study. Findings indicated that the extent to which novice teachers are given professional guidance and support in schools is not enough. It is recommended that induction programmes receive more priority in schools since the first year of teaching is the most important determiner in the teaching career of an individual. / Education management / M.Ed. (Education Management)