Celui-ci a pour objectif de valider l'ensemble des modèles physiques utilisés dans un code de simulation numérique pour simuler un écoulement de type annulaire dispersé en conduite rencontré lors d'une procédure de lavage à eau utilisé dans les raffineries. Pour ce faire une banque de données expérimentale est mise en place sur des configurations représentatives de celles utilisées en condition industrielle. La géométrie retenue comporte une zone horizontale d'injection rectiligne avec un injecteur central, suivi d'un coude à 90° situé dans un plan vertical. Différentes conditions expérimentales permettent d'étudier l'influence de la vitesse du gaz, de la condition d'injection du brouillard et de la pression sur les différents processus physiques. Ces résultats comprenant des visualisations du brouillard et du film pariétale, des mesures de taille et de distribution de gouttes,des mesures de débit et d'épaisseur de film, sont analysés pour faire ressortir les principaux mécanismes d'interaction entre le gaz et la phase dispersée, le gaz et le film liquide pariétal et la phase dispersée et le film pariétal. En parallèle, des premières simulations, avec une approche RANS, sont réalisées avec le code CEDRE de l'ONERA et les résultats sont confrontés aux mesures. / This work has been realised within a CIFRE contract with TOTAL. Its aim was to validate all the physical models used in a computation, which simulates an annular dispersed flow through a pipe used in a water washing process in refinery plants. That is why, a whole set of data has been gathered using experimental boundary conditions which are representative to those used in industrial configurations. The geometry is made of a horizontal pipe with a centred nozzle followed by a 90º elbow in the vertical plane. Several experimental boundary conditions enable one to study the influence of the gas velocity, the type of the spray injection and the pressure on the different physical phenomena. These results including spray and liquid film visualisations, droplets distribution and size measurements as well as liquid film thickness and mass flow measurements were analysed in order to extract the main interaction mechanism between the gas and the dispersed phase, the gas and the liquid film, and the dispersed phase and the annular liquid film. Meanwhile, simulations using a RANS approach were realized with the ONERA code named CEDRE and its results were compared to the gathered measurements.

本研究透過不同股權結構來探討傳統代理問題與核心代理問題對於研發支出投入程度之影響。 本研究將具有金字塔結構或交叉持股結構之企業分類為股權集中之企業，而將不具有金字塔結構或交叉持股結構之企業分類為股權分散之企業。實證分析顯示，在股權分散情況下，傳統代理問題的降低有助於研發支出之提升。其中，董事長兼任總經理、經理人持股比率、董監事持股比率、大股東持股比率、法人持股比率及獨立董事席次比率皆對研發支出之投入有正相關影響。在股權集中情況下，核心代理問題的降低也有助於研發支出之投入。 此外，相較於股權分散之企業，股權集中之企業有著較高的研發支出投入，代表股權集中之企業較有辦法投入較多資源於研發支出上。而透過交乘項之實證分析後，發現相對於股權集中之企業，若股權分散之企業的傳統代理問題能降低，那麼會更有效地提高研發支出以提升企業經營績效。同理也得知，在相對於股權分散之企業，股權集中之企業之核心代理問題若能降低，那麼會更有效地提高研發支出以提升公司價值。 / Based on ownership structures, this study investigates the effects of type I and type II agency problem on R&D expenses for innovation investments. This study classifies both pyramid ownership structure and cross-holding ownership structure as ownership-concentrated structure while others ownership-dispersed structure. The empirical results indicate that under ownership-dispersed structure, the reduction in type I agency problems increases research and development (R&D) expenses in innovation investments. The ways that reduce type I agency problem and boost innovation investments include CEO duality, executive ownership, corporate ownership, block ownership, institutional ownership, and the percentage of board seats held by independent directors. Under the case of ownership-concentrated structure, reduction in type II agency problems lead to increase in R&D expenses for innovation investments. Moreover, comparing with ownership dispersed firms, the ownership concentrated firms spend more in R&D expenses. However, if the dispersed ownership firms can decrease type I agency problems then they spend more in R&D relative to the ownership concentrated firms. By the same token, comparing with ownership-dispersed firms, the reduction in type II agency problems of ownership-concentrated firms will more effectively increase R&D expenses to raise the company value.

Le confinement de polymères incompatibles au sein de particules induit une séparation de phase et conduit à la formation de morphologies particulières (cœur-écorce, hémisphérique…). Cette nanostructuration est à l’origine de propriétés de filmification particulières qui justifient l’utilisation des particules polymères composites dans le cadre d’applications comme la formulation de peintures ou de revêtements. Ce travail s’intéresse au développement d’approches permettant de préparer ces particules polymères composites en une seule étape et en milieu aqueux. La stratégie proposée repose sur le couplage « en simultané » de deux polymérisations distinctes: la polymérisation de cyclooléfines par métathèse (ROMP) et la polymérisation radicalaire par transfert d’atome (ATRP). Après avoir mis en évidence les difficultés liées au couplage de la ROMP et de l’ATRP en milieu dispersé aqueux, deux approches originales faisant intervenir respectivement des conditions de miniémulsion et de microémulsion sont proposées. Pour chacune d’elles, la présentation du principe de la synthèse et l’analyse de ses résultats précèdent l’étude morphologique des particules produites. / So as to broaden the scope of their applications in paints, coatings and impact-resistant plastics, many investigations have been dedicated to the preparation of nanostructured colloids over the past decades. Original morphologies including core-shell, hemispherical and complex occluded structures (raspberry-like, golf ball-like, octopus-like) can now be readily prepared. This work proposes a new straightforward one-pot, one-step, one-catalyst strategy to prepare polymer composite particles based on the simultaneous combination of two mechanistically distinct polymerizations in aqueous dispersed media. Norbornene (NB) and methyl methacrylate (MMA) were converted via Ring-Opening Metathesis Polymerization (ROMP) and Atom-Transfer Radical Polymerization (ATRP), respectively. Two original routes, designed to ensure simultaneous ROMP and ATRP, respectively under mini- and microemulsion conditions, are proposed. Both are successively reviewed on chemical and colloidal levels. Specific attention is paid to the morphologies of the prepared particles.

Dentre os atuais desafios do direito societário brasileiro, a estrutura da propriedade acionária das sociedades por ações de capital aberto e a identificação daqueles que as comandam merecem destaque. O aquecimento das transações realizadas via mercado de capitais e a consolidação dos segmentos especiais de governança corporativa no Brasil resultaram no chamado fenômeno de dispersão acionária, que evidenciou certa ruptura na tradicional estrutura de propriedade acionária exclusivamente concentrada, até então predominante nas companhias brasileiras. Diante desse cenário contrastante, de mudanças no perfil do poder de controle sobre as companhias brasileiras, o presente trabalho apresentará em seu capítulo terceiro, após breve análise das estruturas de capital identificadas em diferentes economias e de retrospectiva sobre a propriedade acionária das companhias brasileiras (a serem apresentadas em seu segundo capítulo), extensa pesquisa empírica realizada com o propósito de identificar a atual estrutura de propriedade acionária predominante entre as companhias brasileiras listadas no segmento especial do Novo Mercado da BMF&BOVESPA (Novo Mercado), e com o objetivo de averiguar a existência do chamado controle societário minoritário entre tais companhias, conforme detalhado nos apêndices desta dissertação. Referida pesquisa empírica representa, ainda, rico processamento da base de dados e informações divulgadas à Comissão de Valores Mobiliários (CVM) pelas companhias listadas no Novo Mercado, e serve de base para a avaliação da necessidade de eventuais mudanças nos conceitos adotados pelo Direito Societário pátrio, tendo em vista entendimento divergente identificado na doutrina e em julgados da CVM no âmbito da possibilidade de existência de um controle societário exercido por acionista ou grupo de acionistas não detentores da maioria do capital social votante, conforme detalhado no quarto capítulo deste estudo. Por fim, serão apresentadas, no quinto e último capítulo, as considerações finais à análise proposta, com destaque para as principais conclusões obtidas na elaboração dos capítulos terceiro e quarto descritos acima, dentre elas a existência do controle societário interno não majoritário (controle minoritário) entre companhias listadas no Novo Mercado, bem como os reflexos dessa constatação no âmbito da prática do Direito Societário. / Among the current challenges of the Brazilian Corporate Law, the structure of the capital ownership of the corporations and the identification of those who exercises control over it remains an important aspect to be taken into consideration when analyzing the main aspects of the Brazilian capital market. The heat up of the transactions carried out through the capital market, and the consolidation of the special corporate governance segments in Brazil resulted in the so called phenomenon of the dispersed ownership, which revealed a rupture from the traditional structure of extremely concentrated ownership, that was prevailing until now among the Brazilian corporations. Given such contrasting scenario of changes in the profile of corporate power over Brazilian corporations, these thesis, after describing, over its first two chapters, the structures of capital ownership existent in different economies and providing a retrospective on the capital ownership of Brazilian corporations, presents, in its third chapter, an extensive empirical research performed with the purposes of identifying the current structure of capital ownership prevailing among the Brazilian companies listed in the Novo Mercado, special segment of the Brazilian Exchange BMF&BOVESPA (the New Market), as well as ascertaining the existence of minority corporate control among such companies, as detailed in the appendixes hereto. The referred empirical research presents, furthermore, detailed data processing in connection with the information disclosed by such companies to the Brazilian Stock Exchange Commission, the Comissão de Valores Mobiliários (CVM), and is also used as basis for reviewing the need of eventual changes in the concepts embodied by the Brazilian Corporate Law, in view of the divergent understanding identified in the Brazilian doctrine and judgments issued by the CVM in connection with the existence of a corporate control exercised by a shareholder or group of shareholders owner of shareholding not representative of the majority of the voting capital stock, as detailed in the fourth chapter of these thesis. Finally, the fifth and last chapter of these study presents the final considerations in connection with the review proposed hereto, highlighting the main conclusions obtained through the elaboration of the third and fourth chapters described above, among them the existence of a not majority internal control (minority control) in companies listed in the New Market, as well as the effects of such conclusion in the light of the practice of corporate law.

O escoamento líquido-líquido, em especial o escoamento óleo-água, vem atraindo a atenção de pesquisadores devido à alta demanda pelo combustível fóssil no atual cenário petrolífero mundial e nacional. Os desafios tecnológicos colocados pelas descobertas de reservas de óleos pesados e altamente viscosos consideram, em especial, a preocupação por minimizar as perdas energéticas nas linhas. Emulsões inversas ou dispersões óleo-em-água, na qual o óleo se encontra disperso de maneira uniforme em água, caracteriza-se pela baixa viscosidade aparente, tornando-se um tipo de emulsão desejável em algumas etapas do transporte de petróleo. Esses fatos tornam essencial o estudo deste tipo de padrão para o dimensionamento e operação ótima de dutos de produção de petróleo. Contudo, não existe ainda um número abrangente de trabalhos sobre padrão disperso líquido-líquido, ao comparar com escoamento em fases separadas. Trabalhos sobre dispersões têm reportado redução de atrito sem a adição de substâncias químicas em regime turbulento. No entanto, não há ainda um entendimento satisfatório do fenômeno. Na maioria dos trabalhos, sendo quase todos realizados com óleos leves e pouco viscosos, a redução é reportada em dispersões água-em-óleo, com escassos trabalhos reportando o fenômeno em dispersões óleo-em-água. A pesquisa realizada tratou do estudo experimental e teórico de dispersões óleo-em-água em tubulações. O escoamento foi caracterizado a partir da obtenção de dados de holdup, gradiente de pressão por fricção, distribuição das fases e padrão de escoamento. Uma teoria foi proposta para explicar a redução de atrito detectada neste trabalho, baseada na existência de um filme fino de água que escoa em contato com a parede do tubo, a baixos números de Reynolds, evitando o contato direto do núcleo turbulento (mistura bifásica) com a parede do tubo. O referido filme líquido foi detectado e quantificado utilizando-se técnica visual. Além disso, um modelo dinâmico baseado na teoria de lubrificação hidrodinâmica foi desenvolvido como tentativa de explicar a formação do filme líquido parietal no escoamento turbulento de dispersões óleo-água. / Liquid-liquid flow, especially oil-water flow, has attracted the attention of researchers due to the high demand for petroleum in the current global scenario. The discovery of reserves of heavy and highly viscous oils creates new challenges which are mainly concerned with reducing the significant pressure drop in pipes. Inverse emulsion or oil-in-water dispersions in which the oil is dispersed in water is characterized by its low effective viscosity, making it a desirable type of emulsion in some steps of oil production. These facts make the study of dispersed liquid-liquid flow essential for the design and optimal operation of oil pipelines. However, the studies on such flow pattern are scanty in comparison to those on separate flows, as stratified and annular flow patterns. Drag reduction in oil-water turbulent flow without the addition of any chemical substance has been reported in some studies. This phenomenon has received increasing attention in recent years, because there is not a satisfactory understanding of its dynamics yet. Most studies, almost all using light oils, report drag reduction in dispersion of water-in-oil, with few studies reporting the phenomenon in oil-in-water dispersions. This research comprises an experimental and theoretical study on oil-in-water dispersions in pipes. Pressure gradient, holdup, phase distribution and flow patterns data were obtained to characterize the two-phase flow. A theory was proposed to explain the drag reduction detected in this work, based on the existence of a thin water film flowing in contact with the pipe wall at low Reynolds numbers, avoiding contact between the turbulent core (mixture) and the pipe wall. The liquid film was detected and quantified using visual technique. In addition, a dynamic model based on the hydrodynamic lubrication theory was developed as an attempt to explain the formation of the liquid film.

Cognitive radio is a recent novel approach for the realization of intelligent and sophisticated wireless systems. Although the research and development on cognitive radio is still in the stage of infancy, there are significant interests and efforts towards realization of cognitive radio. Cognitive radio systems are envisioned to support context awareness and related systems. The context can be spectrum, environment, location, waveform, power and other radio resources. Significant amount of the studies related to cognitive radio in the literature focuses on the spectrum awareness since it is one of the most crucial features of cognitive radio systems. However, the rest of the features of cognitive radio such as location and environment awareness have not been investigated thoroughly. For instance, location aware systems are widespread and the demand for more advanced ones are growing. Therefore, the main objective of this dissertation is to develop an underlying location awareness architecture for cognitive radio systems, which is described as location awareness engine, in order to support goal driven and autonomous location aware systems. A cognitive radio conceptual model with location awareness engine and cycle is developed by inspiring from the location awareness features of human being and bat echolocation systems. Additionally, the functionalities of the engine are identified and presented. Upon providing the functionalities of location awareness engine, the focus is given to the development of cognitive positioning systems. Furthermore, range accuracy adaptation, which is a cognitive behavior of bats, is developed for cognitive positioning systems. In what follows, two main approaches are investigated in order to improve the performance of range accuracy adaptation method. The first approach is based on idea of improving the spectrum availability through hybrid underlay and overlay dynamic spectrum access method. On the other hand, the second approach emphasizes on spectrum utilization, where we study performance of range accuracy adaptation from both theoretical and practical perspectives considering whole spectrum utilization approach. Furthermore, we introduced a new spectrum utilization technique that is referred as dispersed spectrum utilization. The performance analysis of dispersed spectrum utilization approach is studied considering time delay estimation problem in cognitive positioning systems. Afterward, the performance of whole and dispersed spectrum utilization approaches are compared in the context of cognitive positioning systems. Finally, some representative advanced location aware systems for cognitive radio networks are presented in order to demonstrate some potential applications of the proposed location awareness engine in cognitive radio systems.

This thesis explores barriers to the establishment of trust needed for high performing teams due to inequality in the context of a global economy. Postcolonial Theory is introduced to illustrate how inequality is a key aspect of diversity in the current context of the global workplace. Different philosophies underlying the values and norms in organizations are examined to make sense of contemporary approaches to diversity management in terms of how power, difference, and identity are addressed. This provides an understanding of the context of current team development praxis in working with diversity. Using autoethnography, the author tells personal stories of working in diverse teams to convey the complex ways in which power, difference, and identity coalesce in real-life experience. Some theoretical foundations are developed for facilitating the building of team trust in contexts with different philosophical approaches to diversity. Addressing social justice in Organization Development work is considered.

This thesis explores barriers to the establishment of trust needed for high performing teams due to inequality in the context of a global economy. Postcolonial Theory is introduced to illustrate how inequality is a key aspect of diversity in the current context of the global workplace. Different philosophies underlying the values and norms in organizations are examined to make sense of contemporary approaches to diversity management in terms of how power, difference, and identity are addressed. This provides an understanding of the context of current team development praxis in working with diversity. Using autoethnography, the author tells personal stories of working in diverse teams to convey the complex ways in which power, difference, and identity coalesce in real-life experience. Some theoretical foundations are developed for facilitating the building of team trust in contexts with different philosophical approaches to diversity. Addressing social justice in Organization Development work is considered.

The main objective of the thesis is to assess the damage resistance and damage tolerance of the non-conventional dispersed laminates and compare the response with the conventional ones. However, part of the effort is spent on understanding the delamination behavior in multidirectional laminates. In the first part of the thesis, the delamination in multidirectional laminates is studied. The objective is to design a proper stacking sequence, capable of avoiding intralaminar damage (crack jumping), to enable the fracture toughness characterization under pure mode I. The result of this study shows that the higher the crack arm bending stiffness, the lower the tendency to crack jumping. This phenomenon is also studied experimentally and the same conclusion is drawn. / El principal objectiu de la tesi és valorar la resistència al dany i la tolerància al dany dels laminats no-convencionals dispersos i comparar la seva resposta amb la dels laminats convencionals. No obstant, part de l'atenció es dedica a comprendre el comportament de la delaminació en laminats multidireccionals. En la primera part de la tesi, s'analitza la delaminació en laminats multidireccionals. L'objectiu és dissenyar una seqüència d'apilament apropiada per evitar el dany intralaminar (migració de la delaminació) i permetre la caracterització de la tenacitat a la fractura en model. Els resultats d'aquests estudi mostren que a major rigidesa a flexió dels braços de l'esquerda, menor és la tendència a la migració de l'esquerda. Aquest aspecte també s'ha analitzat experimentalment, obtenint les mateixes conclusions.

Στην παρούσα μελέτη διερευνάται η αρχή του φαινομένου της ηλεκτροχημικής ενίσχυσης με την τεχνική της ηλεκτρονικής μικροσκοπίας σήραγγος (STM) και με την τεχνική Kelvin probe. Συγκεκριμένα, με το STM εξετάστηκε το σύστημα Pt(111)/YSZ υπό συνθήκες περιβάλλοντος προκειμένου να διερευνηθούν σε ατομική κλίμακα οι μεταβολές που υφίσταται η επιφάνεια του μονοκρυστάλλου της Pt μετά από ηλεκτροχημική παροχή ιόντων οξυγόνου στην επιφάνειά της. Βρέθηκε ότι το ηλεκτροχημικά παρεχόμενο οξυγόνο από το στερεό ηλεκτρολύτη στην επιφάνεια της Pt(111) δημιουργεί τη δομή Pt(111)-(12x12)-O. Με την τεχνική Kelvin probe μελετήθηκε το έργο εξόδου ηλεκτροδίων σε υδατικά διαλύματα και εν συνεχεία διερευνήθηκε η αρχή του απόλυτου δυναμικού των ηλεκτροδίων στην υγρή ηλεκτροχημεία. Τα αποτελέσματα επιβεβαιώνουν για πρώτη φορά την ισχύ της εξίσωσης: eUWR= ΦW – ΦR στην υγρή ηλεκτροχημεία και τονίζουν ότι το έργο εξόδου των αναδυόμενων ηλεκτροδίων, διαιρούμενο από το μοναδιαίο φορτίο του ηλεκτρονίου e, μπορεί να οριστεί ως το απόλυτο δυναμικό. Μελετήθηκε επίσης η αναγωγή των οξειδίων του αζώτου από C3H6 και από CO παρουσία οξυγόνου σε διεσπαρμένους καταλύτες ροδίου (Rh) και πλατίνας (Pt). Βρέθηκε ότι η αντίδραση αναγωγής του ΝΟ εξαρτάται από το είδος του φορέα και του μετάλλου. Τα αποτελέσματα συγκρινόμενα με αντίστοιχα πειράματα ηλεκτροχημικής ενίσχυσης, ΗΕ, έδειξαν τη βασική ομοιότητα του μηχανισμού της ΗΕ και των αλληλεπιδράσεων μετάλλου-φορέα, που συνίστανται στην διάχυση (backspillover) ιόντων Ο2- από το φορέα στο μέταλλο και την επακόλουθη αλλαγή της ισχύος των χημειοροφητικών δεσμών των αντιδρώντων. Επίσης μελετήθηκε η συμπεριφορά ζεόλιθου Cu-ZSM-5 στην αναγωγή του ΝΟ από προπυλένιο όπου βρέθηκε ότι ο συγκεκριμένος καταλύτης είναι ιδιαίτερα εκλεκτικός σε Ν2 υπό έντονα οξειδωτικές συνθήκες. / Scanning tunneling microscopy (STM) was used to investigate the surface of Pt single crystal catalyst surfaces interfaced with O2- conducting catalyst supports under conditions simulating electrochemical promotion and metal-support interactions. In both cases STM has clearly shown the reversible migration on the catalyst surface of promoting O2- species which are entirely distinct from normally chemisorbed oxygen originating from the gas phase. These observations provide useful information for the mechanism of electrochemical promotion and metal-support interactions, reveal the existence and fast migration of O2-, a most effective anionic promoter, on metal surfaces and underline its role in inducing the phenomena of electrochemical promotion and of metal-support interactions. In the second part of my thesis a two Kelvin probe setup is used for the first time in aqueous electrochemistry, to measure in situ and simultaneously the work functions, ΦW, ΦC and ΦR, of emersed working, counter and reference electrodes, respectively. The results confirm, for the first time, the validity of equation eUWR= ΦW – ΦR in aqueous electrochemistry and underline that the work function of emersed electrodes, divided by the unit charge e, can be used as the absolute potential. Additionally, in the last part of this thesis, it was studied NOx reduction by C3H6 and CO in the presence of oxygen on Rh and Pt dispersed catalysts. It was found that NO reduction depends on the support, but also on the type of the impregnating metal. The obtained results showed the similarity of electrochemical promotion and of metal-support interactions, when compared with corresponding NEMCA experiments. Finally, an ion-exchanged zeolite, Cu-ZSM-5, was used for NO reduction by propylene. It was found that the used zeolite was highly selective to dinitrogen production in high excess of oxygen.