Made available in DSpace on 2016-01-26T12:51:18Z (GMT). No. of bitstreams: 1 marcelomaiacaixetamelo_dissert.pdf: 1810009 bytes, checksum: 1014c04abf9e0627459b0eaa88a963d8 (MD5) Previous issue date: 2007-10-26 / The ileum is approximately the most distal three-fifths of the small intestine and is responsible for digestion and the absorption of foods. The diagnosis of diseases that affect this segment can be achieved by clinical evaluation and complementary examinations. Colonoscopy, not only allows macroscopical analysis, but also enables biopsies to be carried out for histological evaluation. Objective: The objective of this research was to study the terminal ileum of patients submitted to colonoscopy in respect to: 1) correlation of endoscopic and histological parameters; 2) compatibility between the initial histological results evaluation and a review of slides; 3) the chance of individuals with normal ileoscopy and abdominal pain and/or chronic diarrhea presenting with histological alterations. Casuistic and Method: Patients submitted to colonoscopy for varying reasons were prospectively studied. During this examination 47 (42.3%) male and 64 (57.7%) female patients, with ages ranging between 14 and 82 years old (mean 51.6 ? 15 years), were selected with the terminal ileum mucous smooth and without enanthema at endoscopic examinations. Biopsies of the ileal mucosa were obtained for these individuals with the slides being routinely examined during data collection and later reviewed. Results: The correlation between patients with normal xiii ileoscopy and histologically normal ileum was 34.2%. When patients with histologically normal ileum and mild ileitis were analyzed, the correlation was 99.1%. The agreement between the initial histological evaluation and review of slides in respect to normal ileum and mild or moderate ileitis according to the Kappa test was 0.10 (poor agreement). Considering the normal ileum together with mild ileitis and moderate ileitis Groups, the agreement was 0.21 (fair agreement). In patients with normal ileoscopy and abdominal pain and/or chronic diarrhea, the chance of presenting histological alterations by Odds Ratio calculation, was 2.5 times higher than for asymptomatic individuals or those with other symptoms. Conclusions: In patients with the terminal ileum mucosa smooth without enanthema, the correlation between endoscopic and histological findings was high. The concordance between the initial histological results evaluation and the review of slides was not good. The chance of individuals with normal ileoscopy and abdominal pain and/or chronic diarrhea, presenting histological alterations was greater than for asymptomatic individuals or those with other symptoms. / ?leo compreende cerca de 3/5 distais do intestino delgado, sendo respons?vel pela digest?o e absor??o de alimentos. O diagn?stico de doen?as que afetam esse segmento pode ser feito por meio de avalia??o cl?nica e exames complementares. A colonoscopia, al?m da possibilidade de an?lise macrosc?pica, permite realiza??o de bi?psias para avalia??o histol?gica. Objetivo: O objetivo desta pesquisa foi estudar o ?leo terminal de pacientes submetidos ? colonoscopia considerando: 1) correla??o endosc?pica e histol?gica; 2) concord?ncia entre resultados da avalia??o histol?gica inicial e revis?o de l?minas; 3) chance de indiv?duos com ileoscopia normal, portadores de dor abdominal e ou diarr?ia cr?nica apresentarem altera??es histol?gicas. Casu?stica e M?todo: Foram estudados prospectivamente pacientes submetidos ? colonoscopia por diversas indica??es. Durante esse exame foram selecionados 111 pacientes, sendo 47 (42,3%) do sexo masculino e 64 (57,7%) do feminino, com idade entre 14 e 82 anos (51,6 ? 15 anos), que apresentaram ao exame endosc?pico do ?leo terminal mucosa lisa, sem enantema. Foram realizadas bi?psias da mucosa ileal nesses indiv?duos, sendo as l?minas examinadas rotineiramente durante coleta de dados e revisadas posteriormente. Resultados: A correla??o entre pacientes com ileoscopia normal e ?leo histologicamente normal foi 34,2%. Quando a somat?ria dos pacientes com xi ?leo histologicamente normal e ile?te leve foi analisada, constatou-se correla??o de 99,1%. A concord?ncia entre avalia??o histol?gica inicial e revis?o de l?minas considerando-se ?leo normal, ile?te leve e ile?te moderada pelo teste de Kappa foi 0,10 (concord?ncia pobre). Considerando os grupos ?leo normal-ile?te leve e ile?te moderada, a concord?ncia foi 0,21 (concord?ncia razo?vel). Nos pacientes com ileoscopia normal, portadores de dor abdominal e ou diarr?ia cr?nica, a chance de apresentarem altera??es histol?gicas, pelo c?lculo da Odds Ratio, foi 2,5 vezes maior em rela??o ?queles assintom?ticos e ou com outros sintomas. Conclus?es: Nos pacientes com mucosa do ?leo terminal lisa, sem enantema, a correla??o entre achados endosc?picos e histol?gicos foi elevada. A concord?ncia entre resultados da avalia??o histol?gica inicial e revis?o de l?minas n?o foi satisfat?ria. A chance de indiv?duos com ileoscopia normal, portadores de dor abdominal e ou diarr?ia cr?nica, apresentarem altera??es histol?gicas foi maior em rela??o ?queles assintom?ticos e ou com outros sintomas.

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: A low earth orbit satellite system can be useful in numerous communication applications where physical connections are not possible. Communication time available from any point on earth to the satellite is less than one hour per day. This one hour is fragmented into smaller time slots due to the satellite orbiting. This is not much time to transfer data and there is even less time available to transfer data when there are other external factors affecting the system. It is thus crucial to optimise the satellite communications link so that more data can be transferred per orbit. The goal of this thesis is to improve the performance of a low earth orbit satellite communication channel by varying certain parameters of the system, such as the protocol used, modulation scheme, packet size, transmission power etc. and then to observe how these parameters influence the system. The protocols that were chosen to be implemented are CSMA-CA, CSMA-CA with DSSS technology and Round-Robin Polling. A simulator for each protocol was designed with the Opnet platform, so that specific parameters could be changed and the results observed, in order to optimise the communications link between the satellite and ground stations. The results showed that there is no particular configuration of modulation scheme, packet size, transmission power etc. presenting the best overall solution for LEO satellite communications. It must be considered what the specific LEO satellite application would be used for and the characteristics required by that specific application. A suitable configuration must subsequently be chosen from the set of configurations available to satisfy most of the application requirements. / AFRIKAANSE OPSOMMING: ’n Satelliet met ’n lae wentelbaan kan gebruik word in verskeie kommunikasie toepassings waar fisiese verbindinge nie noodwendig moontlik is nie. Die kommunikasietyd van enige punt van aarde af na die satelliet, is minder as een uur per dag. Hierdie tyd word nog verder verklein omdat die satelliet besig is om, om die aarde te wentel. ’n Uur is glad nie baie tyd om data oor te dra nie en in realiteit is daar nog minder tyd beskikbaar as daar eksterne faktore op die sisteem inwerk. Dus is dit baie belangrik om die satelliet kommunikasiekanaal te optimiseer sodat soveel moontlik data as moontlik oorgedra kan word per omwenteling. Die doel van hierdie tesis is om die deurset van die kommunikasiekanaal van n lae wentelbaan satelliet te optimiseer, deur verskeie parameters te verander soos, protokol wat gebruik word, modulasie skema, pakkie grootte, transmissiekrag ens. en dan waar te neem hoe dit die sisteem beïnvloed. Die protokolle wat geïmplementeer is, is CSMA-CA, CSMA-CA met DSSS tegnologie en Round-Robin Polling. ’n Simulator vir elke protokol was ontwerp in die Opnet simulasie platform, sodat die spesifieke parameters verander kon word om die resultate te bestudeer met die doel om die kommunikasiekanaal tussen die satelliet en grond stasies optimaal te benut. Die resultate het bewys dat daar geen spesifieke konfigurasie van modulasie skema, pakkie grootte, transmissiekrag ens. is wat die algehele beste oplossing is nie. Die spesifieke applikasie waarvoor die lae wentelbaan satelliet gaan gebruik word moet geanaliseer word sowel as die spesifieke karakteristieke van daai applikasie. Daarvolgens moet n unieke konfigurasie opgestel word wat meeste van die applikasie se behoeftes bevredig.

Data de aprova??o retirada da vers?o impressa do trabalho. / Incluir a Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) como ag?ncia financiadora. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-12-13T16:15:41Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) alice_lopes_macedo.pdf: 5251789 bytes, checksum: e988c8abc173c91e128980414db14ef9 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-01-03T12:17:24Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) alice_lopes_macedo.pdf: 5251789 bytes, checksum: e988c8abc173c91e128980414db14ef9 (MD5) / Made available in DSpace on 2018-01-03T12:17:24Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) alice_lopes_macedo.pdf: 5251789 bytes, checksum: e988c8abc173c91e128980414db14ef9 (MD5) Previous issue date: 2017 / Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) / A crescente demanda global por combust?veis l?quidos para transporte, gera??o de eletricidade, atividade industrial e produ??o agropecu?ria tem imposto planejamento de a??es direcionadas ao uso de fontes ambientalmente limpas de energia. Os derivados da biomassa s?o alternativas econ?mica e tecnicamente vi?veis aos de origem f?ssil, n?o renov?vel, ora dominantes na matriz energ?tica global. O biodiesel, l?quido formado por uma mistura de ?steres de ?cidos graxos, ? adequado ? opera??o em motores de combust?o interna de ciclo Diesel, em substitui??o ou em complemento ao petrodiesel, ou em outras m?quinas t?rmicas. O prop?sito central do presente trabalho foi o desenvolvimento de um catalisador s?lido economicamente vi?vel, quimicamente eficiente e ambientalmente limpo para a produ??o de biodiesel via processos de transesterifica??o de triacilglicer?is dos ?leos de maca?ba ou de soja, com metanol. Foi preparado o catalisador heterog?neo baseado em iodeto de pot?ssio impregnado em s?lica amorfa (SiO2; derivada de areia da constru??o civil) e misturada a um componente magn?tico sint?tico (maghemita, ?Fe2O3). As estruturas qu?mica, cristalogr?fica e hiperfina essenciais e as propriedades magn?ticas dos materiais precursores e do catalisador s?lido foram investigadas. O teor de ?steres e a composi??o dos biodieseis produzidos foram determinados por cromatografia de fase gasosa acoplada a espectr?metro de massa. A composi??o qu?mica do catalisador, verificada por espectroscopias de energia dispersiva sob feixe de el?trons e por fluoresc?ncia de raios X (FRX), confirmou a ocorr?ncia de Si, Fe, K, e I. As ?reas espec?ficas BET encontradas para os componentes individuais, SiO2, ?Fe2O3 e do catalisador SiO2/KI/?Fe2O3, foram 352, 102, e 19 m2 g-1, respectivamente. A significativa redu??o da ?rea espec?fica do catalisador aponta que os componentes foram efetivamente impregnados no suporte. A morfologia das part?culas visualizadas por microscopias eletr?nicas de varredura e de transmiss?o revela a textura esponjosa do catalisador SiO2/KI/?Fe2O3, similarmente ao suporte de s?lica; o ?xido de ferro magn?tico aparece como material altamente organizado, cristalino, disperso no suporte. Os dados M?ssbauer e da magnetometria do ?xido de ferro magn?tico puro e no catalisador confirmam ser a maghemita, resultando em uma magnetiza??o de satura??o do catalisador de 4,6 emu g-1. O catalisador SiO2/KI/?Fe2O3, usado na transesterifica??o de triacilglicer?is, na propor??o em massa em rela??o ao ?leo da am?ndoa de maca?ba de 4,5% e raz?o molar ?leo:metanol de 1:35, levou ? produ??o de 94,3 massa% de ?steres, ap?s 8 h de rea??o. Foi experimentalmente observado que a maghemita tem comportamento qu?mico-catal?tico sin?rgico com os demais componentes do catalisador. O SiO2/KI/?Fe2O3 foi reutilizado em seis rea??es consecutivas com ?leo de soja, na mesma propor??o do catalisador e raz?o molar ?leo:metanol de 1:35, com rendimentos de 94,5% e tempo reacional de 110 min, para o primeiro ciclo, e de 61,2% e 150 min, para o ?ltimo ciclo. O catalisador, antes e ap?s cada ciclo de reuso, e as al?quotas das rea??es foram analisados por FRX, que mostrou que n?o h? perda significativa dos componentes do catalisador. Os resultados demonstram uma perspectiva tecnol?gica que permite redu??o substantiva do volume de efluentes poluentes e utiliza??o de diferentes mat?rias-primas oleaginosas de alto potencial para a produ??o de biodiesel. / Tese (Doutorado) ? Programa de P?s-gradua??o em Biocombust?veis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The global demand for liquid fuels destined to propel automobile motors and for all other types of transport has been growing significantly over the last decades in response to the needs of the population for mobility. These fuels are also necessary for the generation of electricity to support industrial and agricultural activities. However, the principal concern involved in the generation of mechanical work involves the threat that the effluents from burning fuels, particularly those from fossil origin, impart to the environment. Biomass-derived fuels are energetically, economically and environmentally interesting alternatives to the non-renewable fossil fuels, which still dominate the global energy matrix. Biodiesel, a liquid that is composed of a mixture of esters of fatty acids, is mainly suitable for use in Diesel-cycle internal combustion engines, totally replacing or partially complementing petrodiesel. The main purpose of the present work was the development of an economically viable, environmentally clean and chemically efficient solid catalyst for the production of biodiesel via the transesterification reaction of triacylglycerols from maca?ba or soybean oil with methanol. The proposed heterogeneous catalyst was based on potassium iodide-impregnated particles of amorphous silica (SiO2; derived from construction sand) mixed with a synthetic magnetic iron oxide (maghemite, ?Fe2O3). The essential chemical, crystallographic and hyperfine structures and magnetic properties of the starting materials and of the solid catalyst mixture were assessed by physical laboratory techniques. The ester content and the chemical composition of the biodiesel produced were determined by gas chromatography coupled with mass spectrometry. The chemical composition of the catalyst, as determined by electron energy dispersive and X-ray fluorescence (FRX) spectroscopies, confirmed the occurrence of Si, Fe, K, and I. Specific BET surface areas for the SiO2 and ?Fe2O3 components and for the SiO2/KI/?Fe2O3 catalyst were found to be 352; 102 and 19 m2 g-1, respectively. The significant reduction in the specific area of the catalyst indicates that the solid components were intimately mixed and that KI was indeed impregnated on the support. The morphology of the particles, as visualized from the scanning and transmission electron microscopy images, reveals the spongy texture of the SiO2/KI/?Fe2O3 catalyst, which was quite similar to that of the initial silica support. The atomic framework of the magnetic iron oxide appeared to be a highly organized, crystalline nano-material, relatively well dispersed on the silica support. The M?ssbauer and magnetometric data for the pure magnetic iron oxide and for the catalyst confirm that the component is essentially maghemite. The resulting saturation magnetization of the catalyst mixture was 4.6 emu g-1. From the chemical point of view, this maghemite was found to act synergically with the other components of the catalyst and to significantly improve its catalytic activity. The transesterification reaction of triacylglycerols using the SiO2/KI/?Fe2O3 catalyst at a mass ratio corresponding to 4.5 mass% relative to the maca?ba kernel oil and a methanol:oil molar ratio 30:1 yielded 94.3 mass% of esters after 8 h of reaction. The SiO2/KI/?Fe2O3 catalyst was reused for six consecutive transesterification reactions of triacylglicerols in soybean oil employing the same mass proportion of the catalyst and a methanol:oil molar ratio 35:1. A 94.5% yield of esters was obtained after 110 min of reaction in the first cycle, and a 61.2% yield was obtained in the last reaction cycle after 150 min. The compositions of the catalyst before and after each reaction cycle, along with detection of residual chemical elements in the liquid mixture of esters formed, were duly monitored by FRX. There was no significant leaching of the catalyst components during the reactions. These results open a perspective for (i) a substantial reduction in the volume of polluting effluents and (ii) the use bio-oils from native Brazilian flora (maca?ba) as raw materials for the industrial production of biodiesel.

Pour répondre à une demande, toujours croissante, des services multimédias avancés et pour supporter la connectivité électronique partout sur la planète, le développement de systèmes multimédias à large bande ubiquitaires gagne un grand intérêt aux niveaux académique et industriel. Les réseaux satellitaires en général et les constellations de satellites Low Earth Orbit (LEO) plus particulièrement jouent un rôle essentiel dans le déploiement de ces systèmes. Les constellations de satellites LEO telles que "Iridium" ou "Iridium-NEXT" sont extrêmement coûteuses à déployer et à maintenir. Par conséquent, le prolongement de la durée de leur vie est d'une importance cruciale. Dans la partie principale de cette thèse, nous proposons différentes techniques pour prolonger la durée de vie des services satellitaire dans les constellations de satellites LEO. Dans de telles constellations, les satellites peuvent passer plus de 30% de leur temps sous l'ombre de la Terre, temps pendant lequel ils sont alimentés par des batteries. Bien que les batteries soient rechargées par l'énergie solaire, la profondeur de décharge qu'elles atteignent pendant l'éclipse affecte considérablement leur durée de vie et, par extension, la durée de vie des satellites eux-mêmes. Pour des batteries du même type que celles qui alimentent les satellites "Iridium" et "Iridium-NEXT", une augmentation de 15% de la profondeur de décharge peut pratiquement réduire leur durée de vie de moitié. En raison de la nature très uniforme et symétrique des constellations de satellites LEO, il peut y avoir de nombreux chemins alternatifs entre deux noeuds d'un réseau de satellites. La décision relative à l'envoi de données sur un de ces chemins a un effet important sur la durée de vie du réseau. Dans ce contexte, nous nous concentrons tout d'abord sur le routage et nous proposons deux nouvelles métriques de routage, "LASER" et "SLIM", qui tentent de trouver un équilibre entre la performance et la profondeur de décharge de la batterie dans les constellations de satellites LEO. Notre approche de base est de tirer parti du mouvement déterministe des satellites pour favoriser le routage du trafic sur les satellites exposés au soleil plutôt que sur les satellites éclipsés, diminuant ainsi la moyenne de la profondeur de décharge de la batterie, le tout sans pénaliser les performances. Avec l'utilisation d'une topologie LEO réelle et des requêtes de trafic, nous montrons que LASER et SLIM peuvent augmenter la durée de vie de la batterie de près de 75 % et 100 %, respectivement. Ensuite, nous nous occupons de la consolidation des ressources, un nouveau paradigme pour la réduction de la consommation d'énergie. Il consiste à avoir un sous-ensemble, soigneusement sélectionné, de liens réseau à mettre en veille, et à utiliser le reste des liens pour transporter la quantité requise du trafic. Cela est possible sans causer des perturbations majeures aux activités du réseau, étant donné que les réseaux de communication sont conçus pour des périodes de pic de trafic, avec de la redondance, et des ressources surestimées. Comme solutions à ces problèmes, nous proposons deux méthodes différentes pour effectuer la consolidation des ressources dans les réseaux LEO. Premièrement, nous proposons une métrique sensible au trafic pour quantifier la qualité d'une topologie frugal, nommée "MLU". Le problème étant NP-difficile soumis à un seuil "MLU" donné, nous présentons deux heuristiques, "BASIC" et "SNAP", qui représentent différents compromis en termes de performances et de simplicité. Deuxièmement, nous proposons une nouvelle métrique légère n'utilisant pas de trafic pour quantifier la qualité d'une topologie frugal, nommée "ADI". Après avoir montré que le problème de minimisation de la consommation d'énergie d'un réseau LEO soumis à un seuil donné d'ADI est NP-difficile, nous proposons une heuristique nommé "AvOId" à résoudre. / To meet an ever-growing demand for advanced multimedia services and to support electronic connectivity anywhere on the planet, development of ubiquitous broadband multimedia systems is gaining a huge interest at both academic and industry levels. Satellite networks in general and LEO satellite constellations in particular will play an essential role in the deployment of such systems. Therefore, as LEO satellite constellations like Iridium or IridiumNEXT are extremely expensive to deploy and maintain, extending their service lifetimes is of crucial importance. In the main part of this thesis, we propose different techniques for extending satellite service life in LEO satellite constellations. Satellites in such constellations can spend over 30% of their time under the earth’s umbra, time during which they are powered by batteries. While the batteries are recharged by solar energy, the Depth of Discharge (DoD) they reach during eclipse significantly affects their lifetime – and by extension, the service life of the satellites themselves. For batteries of the type that power Iridium and Iridium-NEXT satellites, a 15% increase to the DoD can practically cut their service lives in half. We first focus on routing and propose two new routing metrics – LASER and SLIM – that try to strike a balance between performance and battery DoD in LEO satellite constellations. Our basic approach is to leverage the deterministic movement of satellites for favoring routing traffic over satellites exposed to the sun as opposed to the eclipsed satellites, thereby decreasing the average battery DoD– all without taking a significant penalty in performance. Then, we deal with resource consolidation – a new paradigm for the reduction of the power consumption. It consists in having a carefully selected subset of network links entering a sleep state, and use the rest to transport the required amount of traffic. This possible without causing major disruptions to network activities. Since communication networks are designed over the peak traffic periods, and with redundancy and over-provisioned in mind. As a remedy to these issues, we propose two different methods to perform resource consolidation in LEO networks. First, we propose trafficaware metric for quantifiying the quality of a frugal topology, the Maximum Link Utilization (MLU). With the problem being NP-hard subject to a given MLU threshold, we introduce two heuristics, BASIC and SNAP, which represent different tradeoffs in terms of performance and simplicity. Second, we propose a new lightweight traffic-agnostic metric for quantifiying the quality of a frugal topology, the Adequacy Index (ADI). After showing that the problem of minimizing the power consumption of a LEO network subject to a given ADI threshold is NP-hard, we propose a heuristc named AvOId to solve it. We evaluate both forms of resource consolidation using realistic LEO topologies and traffic requests. The results show that the simple schemes we develop are almost double the satellite batteries lifetime. Following the green networking in LEO systems, the second part of this thesis focuses on extending the resource consolidation schemes to current wired networks. Indeed, the energy consumption of wired networks has been traditionally overlooked. Several studies exhibit that the traffic load of the routers only has a small influence on their energy consumption. Hence, the power consumption in networks is strongly related to the number of active network elements. In this context, we extend the traffic-agnostic metric, ADI, to the wired networks. We model the problem subject to ADI threshold as NP-hard. Then, we propose two polynomial time heuristics – ABStAIn and CuTBAck. Although ABStAIn and CuTBAck are traffic unaware, we assess their behavior under real traffic loads from 3 networks, demonstrating that their performance are comparable to the more complex traffic-aware solutions proposed in the literature.

Made available in DSpace on 2014-12-17T15:01:48Z (GMT). No. of bitstreams: 1 LedaMOL_TESE.pdf: 3658937 bytes, checksum: 6ad7dbe6b2ec8a6f89d9264905ef89b6 (MD5) Previous issue date: 2009-12-21 / Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1? order / Tecnologias inovadoras que usam materiais tensoativos t?m aplicabilidade em v?rios campos industriais, dentre eles petr?leo e g?s natural. Este estudo busca investigar o uso de um tensoativo, derivado de ?leo de coco (OCS - ?leo de coco saponificado), no processo de recupera??o de compostos org?nicos presentes em efluentes oleosos da ind?stria de petr?leo. Para este fim, foram realizados experimentos em uma coluna de bancada objetivando verificar a influ?ncia do tensoativo OCS na efici?ncia de remo??o de ?leo. Desta forma, foram preparadas emuls?es com quantidades fixas de ?leo (50, 100, 200 e 400 ppm), determinandose a concentra??o ?tima de tensoativo para cada uma delas. Foram, tamb?m, realizados alguns ensaios com ?gua de produ??o da ind?stria de petr?leo, visando comparar o resultado com o das emuls?es. O processo de separa??o consiste no uso de bolhas gasosas formadas quando um fluxo de g?s passa em uma coluna l?quida, com concentra??es de tensoativo, ocorrendo a coalesc?ncia das gotas de ?leo dispersas e, consequentemente, o transporte delas ao topo da coluna, formando uma nova fase oleosa cont?nua. O processo fundamenta-se na satura??o de tensoativo na interface g?s-l?quido, dependendo da concentra??o de tensoativo usada, resultando na flota??o da fase ?leo dispersa. Um filtro de prato poroso, com tamanho de poro que varia de 40 a 250 μm, foi colocado ? base da coluna para permitir uma opera??o hidrodin?mica est?vel. Durante os procedimentos experimentais, o volume operacional da fase l?quida foi mantido constante e a taxa de fluxo de ar variada em cada experimento. Os resultados experimentais do estudo hidrodin?mico demonstraram que a captura do ?leo foi influenciada pelos di?metros das bolhas e vaz?es de ar. Com o aumento da vaz?o de 300 para 900 cm3.min-1, ocorreu um aumento de remo??o da fase ?leo de 44% para 66% e a cin?tica de remo??o do ?leo foi definida como uma rea??o de 1? ordem

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-23T18:59:16Z No. of bitstreams: 1 JoseHiltonDaSilva_DISSERT.pdf: 57424622 bytes, checksum: 239c3696815d52401ee84d224dca0845 (MD5) / Approved for entry into archive by Monica Paiva (monicalpaiva@hotmail.com) on 2017-02-23T19:04:22Z (GMT) No. of bitstreams: 1 JoseHiltonDaSilva_DISSERT.pdf: 57424622 bytes, checksum: 239c3696815d52401ee84d224dca0845 (MD5) / Made available in DSpace on 2017-02-23T19:04:22Z (GMT). No. of bitstreams: 1 JoseHiltonDaSilva_DISSERT.pdf: 57424622 bytes, checksum: 239c3696815d52401ee84d224dca0845 (MD5) Previous issue date: 2014-12-17 / A unidade de destila??o atmosf?rica ? a planta mais importante de uma refinaria de petr?leo. Para levar a opera??o desta unidade pr?ximo ao seu ponto operacional ?timo ? necess?rio medir algumas propriedades chaves, em tempo real, para a atua??o do sistema avan?ado de otimiza??o. Neste contexto um sistema especialista de uma unidade de destila??o de petr?leo bruto foi desenvolvido para realizar a otimiza??o do processo com maximiza??o da produ??o diesel, produto de maior valor agregado, atendendo aos requisitos de qualidade determinados pela Ag?ncia Nacional de Petr?leo, G?s Natural e Biocombust?veis (ANP). A modelagem no processo de destila??o foi realizada por meio de redes neurais artificiais (RNA). As vari?veis operacionais de entrada do processo foram propriedades de petr?leo bruto e vari?veis manipuladas, enquanto que as vari?veis de sa?da do sistema foram definidas como as de qualidades do ?leo diesel. O modelo de RNA constru?do pode ser aplicado na previs?o das vari?veis de qualidade do produto principal da unidade, ?leo diesel,respeito ?s vari?veis de entrada do sistema. Al?m disso, foi desenvolvido um otimizador do processo com o uso de algoritmos gen?ticos (AG?s) com o objetivo de minimizar erros de sa?da do sistema especialista e tamb?m maximizar a produ??o do ?leo diesel. Assim sendo, condi??es de funcionamento ideais foram encontrados usando o banco de dados de conhecimento obtido pelas redes neurais com um m?todo de otimiza??o por algoritmos gen?ticos de acordo com uma fun??o objetivo definido. / A unidade de destila??o atmosf?rica ? a planta mais importante de uma refinaria de petr?leo. Para levar a opera??o desta unidade pr?ximo ao seu ponto operacional ?timo ? necess?rio medir algumas propriedades chaves, em tempo real, para a atua??o do sistema avan?ado de otimiza??o. Neste contexto um sistema especialista de uma unidade de destila??o de petr?leo bruto foi desenvolvido para realizar a otimiza??o do processo com maximiza??o da produ??o diesel, produto de maior valor agregado, atendendo aos requisitos de qualidade determinados pela Ag?ncia Nacional de Petr?leo, G?s Natural e Biocombust?veis (ANP). A modelagem no processo de destila??o foi realizada por meio de redes neurais artificiais (RNA). As vari?veis operacionais de entrada do processo foram propriedades de petr?leo bruto e vari?veis manipuladas, enquanto que as vari?veis de sa?da do sistema foram definidas como as de qualidades do ?leo diesel. O modelo de RNA constru?do pode ser aplicado na previs?o das vari?veis de qualidade do produto principal da unidade, ?leo diesel,respeito ?s vari?veis de entrada do sistema. Al?m disso, foi desenvolvido um otimizador do processo com o uso de algoritmos gen?ticos (AG?s) com o objetivo de minimizar erros de sa?da do sistema especialista e tamb?m maximizar a produ??o do ?leo diesel. Assim sendo, condi??es de funcionamento ideais foram encontrados usando o banco de dados de conhecimento obtido pelas redes neurais com um m?todo de otimiza??o por algoritmos gen?ticos de acordo com uma fun??o objetivo definido.

O presente estudo parte da proposta de um pacto narrativo com o leitor, envolvendo uma dupla operação: renunciar, provisoriamente, o formato usual de uma tese dirigida contra ou a favor do pensamento conservador (sem perder de vista o posicionamento político e filosófico em questão), e assumir, enquanto isso, a complexidade da perspectiva de autores que se apropriaram e polemizaram questões políticas e temas filosóficos tendo em vista o seu tempo. Quanto ao gênero em questão, a proposta de desenvolver uma reunião de ensaios procura delimitar as configurações teóricas que permitiram o incremento de um pensamento conservador. A partir das leituras que Carl Schmitt e Leo Strauss estabeleceram sobre a filosofia de Thomas Hobbes, uma das principais problematizações tratadas aqui é a que vê na filosofia hobbesiana a fundação do liberalismo. Para tanto, a questão da adesão ou da separação entre a filosofia política e a filosofia natural torna-se bastante polêmica no tratamento que ambos os intérpretes dão a Hobbes. Como críticos dos rumos da política contemporânea, Schmitt e Strauss entenderam a instauração filosófica do racionalismo moderno como a base teórica que permitiu, a um só tempo, a consolidação de um Estado político que superou a ordem passada, o incremento de um regime absoluto de dominação da sociedade e a abertura que viabilizou, pelo desenvolvimento técnico da nova ciência da natureza e pelo rebaixamento moral da finalidade da vida humana, a ascensão liberal. Como uma tentativa de compreensão da força e das consequências que tais intérpretes tiveram, o presente estudo ainda explora uma recepção crítica brasileira da obra de Strauss que questiona e limita a interpretação da fundação hobbesiana do liberalismo. / This study proposes a narrative pact with the reader, involving a double operation: a temporary renouncement of the usual format of a thesis directed against or in favour of conservative thinking (without losing sight of the political and philosophical positioning in question), and assuming, meanwhile, the complexity of the perspective of authors who take political issues and philosophical subjects aiming at polemizing and debating problems that belong to their own times. As to the literary genre, the proposal of making up a set of essays aims to delimit the theoretical settings that enabled the development of a conservative thought. Considering the interpretations that Carl Schmitt and Leo Strauss set out concerning the philosophy of Thomas Hobbes, a major question treated here is that which sees the Hobbesian philosophy as the foundation of liberalism. For this purpose, the issue of adherence or separation between political philosophy and natural philosophy becomes quite provocative in the way both authors treat Hobbes. As critics of the contemporary political directions, Schmitt and Strauss consider the settlement of modern philosophical rationalism as the theoretical basis that made at the same time possible the consolidation of a political State that overcame the former order of politics, the instauration of an absolute regimen of domination of the society and, finally, the breach which, through the technical improvement of the new science of nature and the debasement of the moral purpose of human life, made the liberal ascension feasible. As an attempt to understand the strength and the consequences that such interpreters had, this study also explores the Brazilian critical reception of the works of Strauss, which discusses and delimits the interpretation of the Hobbesian foundation of liberalism.

It is the purpose of this investigation to examine his popularity and influence in the United States during this period so as to provide a basis for a considered and adequate understanding of the problems and their implications.

L’augmentation depuis une trentaine d’années des maladies infectieuses dites émergentes ou ré-émergentes chez l’homme, causées à plus de 70% par des pathogènes issus d’espèces hôtes animales (i.e. Ebola, SIDA), stimule l’étude de systèmes éco-épidémiologiques à l’interface entres populations humaines et animales (i.e. sauvages et/ou domestiques).Le contact entre hôtes est un phénomène important dans l’étude de ces systèmes car il permet la transmission des pathogènes entre individus et la diffusion de maladie au sein et entre populations. Nous avons choisi la maladie de la fièvre aphteuse comme modèle d’étude de la transmission de pathogènes des populations sauvages vers les populations domestiques. Le buffle africain (Syncerus caffer) étant le réservoir présumé de cette maladie fortement contagieuse, nous nous sommes interrogés sur les conditions de transfert au bétail (Bos taurus et Bos indicus) du virus aphteux aux frontières de trois parcs nationaux africains qui constituent des interfaces entre espaces anthropiques et protégés perméables aux mouvements d’animaux. Dans le cadre de ce doctorat 4 protocoles ont été mis en place entre 2010 et 2011 au Zimbabwe. Premièrement, des colliers GPS (Global Positionning System) ont été déployés sur des bovins sauvages/domestiques pour décrire leurs déplacements dans le paysage et quantifier les contacts interspécifiques. Des colliers furent également posés sur l’une des espèces prédatrices de ces ongulés: le lion (Panthera leo). L’intégration de la guilde des prédateurs nous a permis d’estimer les modifications de l’utilisation de l’espace par les herbivores en réponse à la présence de carnivores et les conséquences en termes de contacts et de transmission interspécifique de pathogènes. Deuxièmement, un suivi longitudinal sérologique sur le bétail a complété le protocole télémétrique avec des prélèvements répétés sur des individus marqués selon le cycle saisonnier. Troisièmement, les contacts au sein des populations de bovins domestiques ont été caractérisés par des enquêtes auprès des éleveurs. Quatrièmement, le rôle potentiel de la diversité des hôtes sur le risque infectieux d’un écosystème a été exploré par l’estimation de densité de macro-parasites dans le paysage selon une variation de la gamme d’hôtes potentiels (i.e. (i) sauvages, (ii) sauvages et domestiques et (iii) uniquement domestiques).Nos résultats montrent que (1) les taux d’interaction interspécifiques, estimés par télémétrie, varient entre sites et présentent une saisonnalité prononcée (i.e. pic saison sèche chaude). (2) La distribution des ressources conditionne la périodicité et la distribution de ces contacts dans les différents compartiments du paysage. (3) La fréquence des incursions du bétail dans un espace protégé ainsi que les taux de contacts avec les buffles influencent positivement la probabilité d’acquisition d’anticorps anti-aphteux chez le bétail. La probabilité de perte d’anticorps est également fonction du niveau d’interaction avec les buffles mais selon une relation négative. (4) La densité du réseau d’interaction intra-spécifique domestique influence positivement l’incidence sérologique de la fièvre aphteuse. (5) La présence de prédateurs supérieurs dans le paysage permettrait de limiter les incursions du bétail dans les espaces protégés et diminuerait la probabilité d’infection par les populations d’hôtes sauvages. (6) Enfin les densités de macro-parasites dans la végétation sont supérieures dans des espaces communaux sans interaction avec les populations sauvages et où la richesse spécifique des hôtes est plus faible. Les résultats de cette étude sur la transmission interspécifique de pathogènes entre populations sauvages et domestiques dans les écosystèmes tropicaux ouvrent des champs de réflexion encore largement inexplorés, notamment sur l’évolution de la virulence et des modes de transmission des pathogènes ayant comme hôtes des populations sympatriques sauvages et domestiques. / Emerging or re-emerging diseases in human populations have increased over the last thirty years. Since 70% of such diseases are caused by pathogens originating from animal hosts (i.e. Ebola, AIDS, and avian influenza), this increase has prompted the study of eco-epidemiological systems that occur at the interface between human and animal populations (i.e. wild and/or domestic). Contacts between hosts are particularly important factors in these systems since they result in pathogen transmission among individuals and, therefore, disease diffusion within and among populations. We used foot-and-mouth disease (FMD) as a model to study pathogen transmission from wild to domestic populations. As the African buffalo (Syncerus caffer) is the presumed reservoir of this highly contagious disease, we examined the conditions in which the virus was transmitted to cattle sensitive to the disease (Bos taurus and Bos indicus) at the borders of African national parks; these areas are interfaces between anthropogenic and protected areas in which animals can move freely.In the context, 4 protocols were implemented between 2010 and 2011 in Zimbabwe. First, GPS (Global Positioning System) collars were placed on cattle and buffalo in order to describe and analyze their movements across the landscape as well as to quantify interspecific contacts. In one of the study sites, collars were attached to one of the predators of these ungulates: the lion (Panthera leo). By integrating the predator guild into our telemetry protocols, we could examine the potential changes in spatial use by cattle and buffalo in response to predator presence and their consequences for contact dynamics and interspecific pathogen transmission. Second, a longitudinal serological survey was conducted in which tagged individuals were sampled repeatedly over the course of different seasons. Third, to characterize contacts within the domestic host population, interviews were conducted with cattle owners regarding their husbandry practices across seasons. Fourth, to describe the potential role of host diversity in ecosystem infection risks, macroparasite density (i.e. ticks) was estimated for landscape compartments that contrasted in terms of potential hosts present (i.e. (i) wild, (ii) domestic and wild, and (iii) domestic only).Our study primarily shows the following results. (1) Interspecific interaction rates, as estimated by telemetry, vary between sites and have a pronounced seasonality (peak occurs during the hot dry season). (2) Resource distribution (i.e. water and grazing areas) seems to condition the frequency and distribution of these contacts in the different landscape compartments. (3) Cattle incursion frequencies into protected areas and the frequency and intensity of contact with buffalo significantly positively affect the probability of foot-and-mouth antibody acquisition in cattle. The probability of antibody loss in cattle is also a function of diminished rates of interaction with buffalo. (4) Intraspecific interaction densities positively influence FMD serological incidence in cattle. (5) Top predator presence in the landscape could limit cattle incursion into protected areas and reduce the likelihood of their being infected by wild host populations. (6) Finally, the estimated densities of macroparasites in the vegetation were higher in communal spaces where there was no interaction with wild hosts and where host species richness was weak.The results of this study on the interspecific transmission of pathogens between wild and domestic populations in tropical ecosystems encourage the exploration of research topics that are still largely unexplored, including the evolution of virulence transmission modes of pathogens hosted by sympatric wild and domestic populations.

La philosophie politique de Leo Strauss a inspiré aux États-Unis des disciples bien au-delà des départements de philosophie. En créant une communauté de conversation, les « straussiens » ont insufflé à l’étude et à l’activité politique un style de pensée irréductible aux sensibilités libérale et conservatrice contemporaines, bien qu'ils aient principalement choisi de dialoguer avec le conservatisme politique naissant. Le conservatisme lincolnien qu’ils ont adopté en est une version modérée par le rationalisme du premier constitutionalisme américain et trouve son origine dans la réhabilitation polémique de la science politique aristotélicienne. En effet, cette science politique les a conduit à interpréter le constitutionalisme à la lumière des principes des pères fondateurs de la République américaine. / The Political Philosophy of Leo Strauss has a far wider sphere of influence in America than the departments of Philosophy. By creating their own community of conversation, the “straussians” inflected to study and political activity a style of thought beyond contemporary liberalism and conservatism, even if Straussians mainly chose to converse with new born political conservatism. The lincolnian conservatism they embraced is one moderated by the rationalism of the first American constitutionalism, and has foundings in the reenforcement of the aristotelician political science. This Political Science led them to read the constitutionalism thanks to the principles of the Founding Fathers of the American Republic.