Toxoplasma gondii, Neospora caninum et Plasmodium falciparum sont des parasites protozoaires intracellulaires obligatoires, respectivement responsables de la toxoplasmose, de la néosporose et du paludisme. Les différents traitements mis en œuvre reposent sur une association médicamenteuse. Cependant, des échecs thérapeutiques et des résistances aux traitements ont été décrits. Notre travail a porté sur l’identification de molécules actives isolées par Chomatographie de Partage Centrifuge (CPC) à partir d’extraits d’écorces d’Anogeissus leiocarpus, un arbre d’Afrique de l’ouest connu pour son activité antipaludique, et de dix arbres de la région Champagne-Ardenne. Nous nous sommes penchés, dans un premier temps, sur l’activité antiparasitaire des fractions obtenues à partir d’extrait d’écorce d’A. leiocarpus. La trachélospérogénine E et l’extrait global sans tanin se sont révélés actifs, notamment en inhibant l’invasion des cellules hôtes par T. gondii. Cet extrait a également préservé la survie des souris atteintes de toxoplasmose chronique. Les mêmes composés naturels ont eu un effet contre N. caninum et P. falciparum. Dans une seconde partie, 30 extraits d’écorces de dix arbres de la région Champagne-Ardenne ont été testés sur T. gondii et N. caninum. Les composés responsables de l’activité antiparasitaire présents chez Alnus glutinosa semblent être la bétuline et ses dérivés. Dans la dernière partie, nous nous sommes intéressés à l’activité de 400 molécules de synthèse de la Pathogen Box. Huit d’entre elles ont eu un effet significatif contre T. gondii, dont trois avec une sélectivité importante. Des expérimentations sont toutefois à réaliser pour N. caninum. / Toxoplasma gondii, Neospora caninum and Plasmodium falciparum are mandatory intracellular protozoan parasites and are responsible for toxoplasmosis, neosporosis and malaria, respectively. The different treatments used are based on drug combination. However therapeutic failures and drug resistances have been described. Our work focused on the identification of active compounds isolated by Centrifugal Partition Chromatography (CPC) from crude barks extracts from Anogeissus leiocarpus, a West African tree known for its antimalarial activity, and ten trees from the Champagne-Ardenne region. First we studied the activity of the fractions obtained from the crude bark extract from A. leiocarpus. Trachelosperogenin E and the global extract without tannin showed a good activity by inhibiting host cell invasion by T. gondii. The latter was able to preserve mice survival toward chronic toxoplasmosis. These extracts were also active on N. caninum and P. falciparum. In a second part 30 crude barks extracts from ten trees located in the Champagne-Ardenne region were screened on T. gondii and N. caninum. Compounds responsible for the antiparasitic activity found in Alnus glutinosa were especially betulin and its derivatives. In the last part of this study we focused on the antiparasitic activity of 400 synthetic molecules from the Pathogen Box. Eight out of them were significantly efficient against T. gondii, among which three showed an important selectivity. Further experiments must be completed in the case of N. caninum.

Made available in DSpace on 2016-04-28T18:22:26Z (GMT). No. of bitstreams: 1 Rodrigo Fernando Assis dos Santos.pdf: 1536485 bytes, checksum: a5ecc665cf98dff5e1e30e09968b8a13 (MD5) Previous issue date: 2011-11-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This research discusses the concept of language present in George Orwell´s book 1984 and relates it with the official concept of language of Russia during the 1920´s and 1930´s . For doing this, we chose as study object the book 1984 from which we selected newspeak as the corpus of analyses. Newspeak consists of a language system that´s is being created by the government of the plot and once it is finished and put into practice, would impeach people to have different opinions from the government and the existence of the other languages would also be impossible. The main feature of newspeak is that it is being constructed through the destruction of the current language. On the other side, we have the official Russian linguistics of the 30´s that has a similar project of destruction of the linguistic material and creation of a single universal language. Our objective in this research is to describe, analyze and interpretate through the linguistic-discursive newspeak material, the discourses that constitutes the book and establish dialogic relations between newspeak and the official russian linguistics of the 30´s, period which the book makes analogies. We inquire in this research what is the concept of language of Newspeak and the official russian linguistics of the 1920´s and 1930´s, which dialogic relations can be established between both concepts, which dialogic relations can be stablished between the newspeak lexical group that relates crime with the idea of disagreement of the government policies and the stanist society concerning the same matter and which language knowledge our dialogic relation meets. This research reconstruct some discourses about the Russian revolutionary period since the czarism regime until the great purge, it also identifies the official Russian linguistics theory of the 20´s and 30´s, and shows how 1984 materialize the discourses concerning the speech restriction policies that come from this historical period. Our methodology for the corpus´ construction was done based on the following steps; a) Describe the process of destruction of the current language; b) Identification of the term Newspeak and the terms in Newspeak through all narrative; (c) Construction of a glossary that has the definition of the words in Newspeak. Through the description of newspeak and the analyses of two linguistics marks, it was possible to realize that the human language either in life or in art, is able to create compensatory mechanisms that weakens and cancel the forces that struggles to finish with the heteroglossia that keeps the human language ideologically saturated. We also indentify the diference between the fictional language and the scientific one: the former there is not any diference between the act of uttering and the utterance, whereas the latter this difference is part of the discourse genre. This research is based on Bakhtinian´s circle theory, that discusses language through its social historical point of view. We used the concept of axiology, ideological sign, infrastructure and superstructure, monologism, dialogism, centripetal forces and centrifugal forces / Este trabalho discute o conceito de língua/linguagem em 1984 de George Orwell e relaciona esse conceito com o da linguística oficial russa das décadas de 1920/1930. Para tanto, selecionamos, especificamente, a novilíngua como corpus de pesquisa. A novilíngua consiste em um sistema linguístico elaborado pelos detentores do poder da ficção orwelliana que, quando finalizado e colocado em uso, impediria a expressão de opiniões contrárias ao regime e a existência de outras línguas. A característica central para a existência da novilíngua é a destruição da língua vigente. Ao pesquisarmos a política linguística oficial russa das décadas de 1920 e 1930, descobrimos um projeto similar de destruição das línguas existentes e de criação de uma língua única. Nosso objetivo de pesquisa, portanto, é descrever, analisar e interpretar, por meio da materialidade linguístico-discursiva da novilíngua, os discursos históricos que atravessam a obra e, a partir daí, estabelecer relações dialógicas entre o conceito de língua/linguagem de 1984 e esse mesmo conceito na linguística oficial russa das décadas de 1920/1930. Questionamos em nosso trabalho qual é o conceito de língua/linguagem da novilíngua e da linguística oficial russa das décadas de 1920/1930, quais relações dialógicas podem ser estabelecidas entre o conceito da novilíngua e esse mesmo conceito da linguística oficial russa dos anos 1930, quais relações dialógicas podem serestabelecidas entre o léxico da novilíngua, que trata o pensamento discordante ao sistema totalitário como crime, e a sociedade stalinista no que diz respeito à restrição da liberdade de expressão e quais conhecimentos sobre a linguagem humana nossa análise dialógica vai de encontro. Este estudo recupera alguns discursos que circulam sobre a história da Rússia desde o final do período czarista até o auge do expurgo stalinista, identifica a teoria linguística oficial da Rússia das décadas de 1920/1930 e mostra como a obra 1984, de Orwell, materializa os discursos advindos desse período histórico. Nossa metodologia para composição do corpus e descrição da novilíngua obedeceu à seguinte dinâmica: a) descrever o processo de destruição da língua vigente para a construção da novilíngua; b) levantamento do termo novilíngua e dos termos em novilíngua, em toda a narrativa; c) construção de um glossário que contém a definição das palavras em novilíngua. Por meio da descrição da novilíngua e da nossa respectiva análise, foi possível constatar que a linguagem humana, tanto na vida como na arte, é capaz de criar mecanismos compensatórios que atenuam e anulam as forças que querem acabar com o plurilinguísmo e assim manter a linguagem humana, mesmo sob forte coerção de sistemas políticos totalitários, pluriacentuada e ideologicamente saturada. Identificamos também a diferença entre a linguagem científica e a ficcional: na linguagem científica não há divergência entre o enunciado e a enunciação; na linguagem ficcional essa divergência é constituinte. Este trabalho está embasado pela teoria Bakhtiniana, que discute a linguagem pelo seu viés sócio-histórico ideológico. Utilizamos os conceitos de axiologia, signo ideológico, infraestrutura e superestrutura, dialogismo, forças centrípetas e centrífugas.

Cette thèse est le fruit d’un partenariat entre la société Johnson Controls et l’université Bordeaux1. L’objectif s’inscrit dans le cadre d’un projet de développement de pompe à chaleur innovante et est de développer un compresseur centrifuge à haute compression. Pour ce faire, un modèle numérique a été créé afin de simuler l’écoulement dans ce type de compresseur. Afin de respecter des impératifs industriels, une première géométrie a été établie par modifications itératives de divers paramètres et analyse des performances induites. L’écoulement a ensuite été étudié plus précisément, particulièrement pour mieux comprendre l’apparition des décollements. Enfin, une étude instationnaire de l’écoulement dans le diffuseur a été effectuée. Au delà des phénomènes physiques étudiés et appréhendés au cours de ce processus, c’est avant tout une méthodologie qui valorise ce travail. / This thesis is the result of a partnership between the company Johnson Controls and the university Bordeaux1. The objective is part of a project to develop innovative heat pump and involves the design of a high head centrifugal compressor. To do this, a numerical model is created to simulate the flow in this kind of compressor. To observe industriel deadlines, a first geometry was established by iterative changes of various parameters in analysing induced effiencies. The flow was then studied further, especially to better understand the onset of flow separation. Finally, a study of unsteady flow in the diffuser was performed. Beyond the physical phenomena investigated and comprehended during this process, it is firstly a methodology that values this work.

Future solar sail and solar power satellite missions require deployment of large and lightweight flexible structures in space. One option is to spin the assembly and use the centrifugal force for deployment, stiffening and stabilization. Some of the main advantages with spin deployment are that the significant forces are in the plane of rotation, a relatively simple control can be used and the tension in the membrane or web can be adjusted by the spin rate to meet the mission requirements. However, a successful deployment requires careful development of new control schemes. The deployment rate can be controlled by a torque, applied either to a satellite in the center or by thrusters in the corners, or by deployment rate control, obtained by tether, spool braking or folding properties. Analytical models with only three degrees of freedom were here used to model the deployment of webs and membranes for various folding patterns and control schemes, with focus on space webs folded in star-like arms coiled around a center hub. The model was used to investigate control requirements and folding patterns and to obtain optimal control laws for centrifugal deployment. New control laws were derived from the optimal control results and previously presented control strategies. Analytical and finite element simulations indicate that the here developed control laws yield less oscillations, and most likely more robustness, than existing controls. Rotation-free (RF) shell elements can be used to model inflation or centrifugal deployment of flexible memebrane structures by the finite element method. RF elements approximate the rotational degrees of freedom from the out-of-plane displacements of a patch of elements, and thus avoid common singularity problems for very thin shells. The performance of RF shell elements on unstructured grids is investigated in the last article of this thesis, and it is shown that a combination of existing RF elements performs well even for unstructured grids. / QC 20100729

The aim of this thesis has been to provide the reader with an intuitive insight into the mechanisms of the Coriolis effect. Apart from thoroughly describing the phenomenon, the essay attempts to eliminate as many myths prevailing around the Coriolis effect as possible. To get there, only a few mathematical derivations and calculations have been presented – the focus has been on a pure conceptual level. Furthermore, delusive textbook explanations have been examined and discussed in case studies. In the conclusion, the goal is reached by summarising the sought intuitive description of the Coriolis effect into one single sentence.

Abstract The influence of rotating and cross flow effect on local heat transfer coefficient and flow visualization for a single confined air/water jet with jet-to-wall spacing from 5 to 11.4, jet Reynolds number from 6500 to 26000, rotational Reynolds number from 0 to 112000, curvature ratio from 150 to , ratio of crossflow massflux to jet mass flux from 0 to 2, and the heat flux from 1430 to 12890W/m2 were reported. The local heat transfer coefficient for air/water along the surface is measured and the effect of the rotation, the jet-to-wall spacing, the surface curvature, local and average Nusselt number, are presented and discussed. Furthermore, flow visualization was made in the present study. Based on the experimental result, it is found that the rotation will induce the centrifugal and coriolis force. It also shows that the heat transfer response will be decreased when the impinging direction parallel to the rotating direction, and increased when impinging direction perpendicular to the rotating direction. Crossflow effect will make Nusselt number decrease to 48% when M=2. Moreover, the roughen surface will increase the heat transfer coefficient up to 22% due to the secondary flow. The flow visualization is used to observe the transition of laminar to turbulence flow and to calculate the boundary layer thickness.

In recent years, bulk amorphous alloys and nanocrystalline materials have been synthesized in a number of ferrous and non-ferrous based alloys systems, which have gained some applications due to their unique physico-chemical and mechanical properties. In the last decade, Zr-based alloys with a wide supercooled liquid region and excellent glass forming ability have been discovered. These systems have promising application fields due to their mechanical properties / high tensile strength, high fracture toughness, high corrosion resistance and good machinability. In this study, the aim is to model, synthesize and characterize the Zr-based bulk amorphous alloys. Initially, theoretical study on the basis of the semi-empirical rules well known in literature and the electronic theory of alloys in pseudopotential approximation has been provided in order to predict the potential impurity elements that would lead to an increase in the GFA of the selected Zr-Ni, Zr-Fe, Zr-Co and Zr-Al based binary systems. Furthermore, thermodynamic and structural parameters were calculated for mentioned binary and their ternary systems. According to the theoretical study, Zr67Ni33 binary system was selected and its multicomponent alloys were formed by adding its potential impurity elements / Mo, W and Al. Centrifugal casting method was used to produce alloy systems. Structural characterizations were performed by DSC, XRD, SEM and EDS methods. In the near-surface regions of Zr60Ni25Mo10W5 and Zr50Ni20Al15Mo10W5 alloys, amorphous structure has been observed. Experimental studies have shown that Zr-Ni based systems with impurity elements Mo, W and Al, not widely used in literature, might be good candidates for obtaining high GFA.

The aim of this study is to synthesize and characterize new bulk amorphous alloys in the Ni- based systems. Theoretical studies on the basis of semi-empirical rules and the electronic theory of alloys in pseudopotential approximation has been provided in order to predict the impurity elements that will lead to an increase in the glass forming ability of Ni-based alloy systems. Glass forming ability of ten different compositions of alloys of Ni-Nb, Ni-Fe, Ni-B, Ni-Hf and Ni-Cr was simulated by using FORTRAN programs based on pseudopotential theory. In addition to the binary alloys, ternary alloys, which were formed by addition of 1 at% of third element to these systems, were also simulated. Since ordering energy is an indicator of glass forming ability, theoretical studies allowed to predict the effect of various third elements on the formation of amorphous phase. Furthermore, ordering energies were also used to calculate other parameters important for glass forming ability. In the second part of the study, on the basis of theoretical results, a series of casting experiments were done. Different compositions of Ni-Nb, Ni-Nb-Sn and Ni-Nb-Al alloys were cast in the centrifugal casting machine. Alloys were melted in alumina crucibles and cast into the copper moulds. Characterizations of cast alloys were done by the use of Metallography, SEM, XRD and DSC. Fully amorphous Ni52Nb41Al7 alloy was synthesized in bulk form with 0.8 mm thickness.

The aim of this study, which was carried out in two main parts, is to investigate the glass forming ability of Fe-based systems. The first part involves the theoretical modeling to cover the requirement of a predictive model to identify the Fe-based alloy families that have high glass forming ability in the frame of atomistic and thermodynamic approach. The second part involves the experimental investigations to prove the results of the conducted theoretical modeling studies. For this purpose, in the first part, theoretical investigations were performed to identify the third alloying elements that will lead to an increase in the glass forming ability on the base of electronic theory of alloys in pseudopotential approximation for selected Fe- based systems, Fe - (B, Zr, Nb, C, W). In the experimental part, in the frame of the theoretical investigation results, one of the theoretically modeled binary system, and the third alloying elements that were predicted to lead an increase in the glass forming ability of the selected binary system, were determined. As a first step, designated compositions were synthesized by using low grade conventional Fe-B alloy as a raw material by using centrifugal casting technique and copper mold casting method. To compare the results, same compositions were also cast from the high purity elements by using the same technique and method. For the characterization of these cast specimens, DSC, XRD, SEM, EDS and metallographic examination techniques were used. Amorphous structure was successfully obtained in the thin sections of the wedge-cast samples for Fe-B-Nb and Fe-B-W ternary systems.

CAPES / A bomba centrífuga submersa (BCS) é utilizada na indústria do petróleo como uma técnica de elevação artificial. Entretanto, o bombeamento de petróleo está associado a escoamentos de óleo de diferentes viscosidades. Esta condição leva a degradação do desempenho em relação à operação com água, na qual a bomba é originalmente projetada. Neste cenário no presente trabalho é desenvolvido um estudo numérico do escoamento em três estágios de duas BCSs semi-axiais. As equações transientes da conservação da massa e do balanço da quantidade de movimento, que modelam o escoamento nas BCSs, são resolvidas numericamente utilizando o programa computacional comercial Ansys-CFX. A turbulência do escoamento foi modelada utilizando o modelo SST. Os resultados numéricos obtidos foram comparados contra dados experimentais e de catálogo mostrando uma boa concordância, para uma grande faixa de viscosidades e rotações. Grupos adimensionais (n, n, n e Re) foram usados para avaliar a degradação do desempenho das BCSs. Além disso, os fenômenos envolvidos no escoamento no interior do rotor das bombas centrífugas foram analisados através dos campos de velocidade obtidos numericamente. A partir dos resultados numéricos foi verificado que a degradação do desempenho é diretamente relacionada com o número de Reynolds de rotação, Re. Também, observou-se que a degradação do desempenho ocorre para uma rotação específica normalizada constante n, no qual bombas de diferentes geometrias apresentaram degradação do desempenho similar. Além disso, dados experimentais e os resultados numéricos obtidos foram consistentes quando comparados com a relação entre os fatores de correção para a vazão e altura de elevação propostas por Stepanoff (1967). Uma definição de número de Reynolds modificado foi proposta e relaciona o fator de correção para altura de elevação com a viscosidade. Além disso, uma correlação entre o fator de correção para altura de elevação e o número de Reynolds modificado foi proposta, apresentando boa concordância. A partir das correlações obtidas, foi proposto um método para prever o desempenho de bombas centrífugas operando com fluidos de alta viscosidade, sendo comparado com outras metodologias encontradas na literatura. Certamente, as informações extraídas são relevantes para o entendimento do escoamento de fluidos de alta viscosidade em bombas, especialmente em BCSs semi-axiais de múltiplos estágios. / Electrical Submersible Pump (ESP) is used as an artificial lift technique. However, pumping viscous oil is generally associated with low Reynolds number flows. This condition leads to a performance degradation respect to the performance expected from the regular operation with water that most of the centrifugal pumps are originally designed for. These issues are considered in this investigation through a numerical study of the flow in two different multistage, semi-axial type ESPs. This investigation is carried out numerically using a Computational Fluid Dynamics (CFD) package, where the transient RANS equations are solved numerically. The turbulence is modeled using the SST model. Head curves for several operating conditions are compared with manufacturer’s curves and experimental data for a three-stage ESP, showing good agreement for a wide range of fluid viscosities and rotational speeds. Dimensionless numbers (n, n, n e Re) are used to investigate performance degradation of the ESPs. In addition, flow phenomena through the impellers of the ESPs are investigated using flow field from numerical results. Results show that performance degradation is directly related to rotational Reynolds number, Re. In addition, it was verified that performance degradation occurs for constant normalized specific speedn, which shows that performance degradation occurs similarly for different centrifugal pumps. Moreover, experimental data and numerical results agreed with a correlation from literature between head and flow correction factors proposed by Stepanoff (1967). A definition of modified Reynolds number was proposed and relates the head correction factor to viscosity. A correlation between head correction factor and the modified Reynolds number was proposed, which agreed well with numerical and experimental data. Then, a method to predict performance degradation based on the previous correlations was proposed. This method was compared with others from literature. In general, results and conclusions from this work can also be useful to bring more information about the flow of highly viscous fluids in pumps, especially in semi-axial, multistage ESPs.