L'objectif général de cette thèse est d'examiner le lien entre les traits de personnalité évalués selon l'approche des cinq facteurs et les résultats des traitements psychosociaux auprès de jeunes adultes présentant un premier épisode psychotique. Afin d'atteindre cet objectif, 129 personnes ont été recrutées à participer à une étude expérimentale randomisée. Les participants ont été assignés soit à un groupe de thérapie cognitive-comportementale, soit à un groupe d'entraînement aux habiletés sociales visant la gestion des symptômes, soit à une liste d'attente. Les participants ont complété pré- et post-traitement le Questionnaire bref de personnalité NEO Révisé (Costa & McCrae, 1992), l'Échelle abrégée d'évaluation psychiatrique (Lukoff et al., 1986; Ventura et al., 1993) et l'Échelle d'adaptation cybernétique (Edwards & Baglioni, 1993). Dans le premier article, les profils de personnalité et la stabilité temporelle des traits de personnalité des jeunes adultes présentant un premier épisode psychotique ont été étudiés. Les résultats révèlent différents profils de personnalité et une stabilité des traits de personnalité. Dans le second article, les profils de personnalité et la valeur prédictive des traits de personnalité ou des profils sur les résultats thérapeutiques ont été investigués. Les résultats révèlent aussi différents profils de personnalité, aucun spécifiquement lié aux symptômes. Aucun lien n'a pu être rapporté entre les traits de personnalité et l'amélioration symptomatologique. Toutefois, les traits de personnalité et les profils sont liés à l'amélioration des stratégies actives d'adaptation. Dans le dernier article, la valeur prédictive des traits de personnalité sur les résultats thérapeutiques selon le groupe de traitement spécifique a été étudiée. Les résultats démontrent un lien entre les traits de personnalité et l'amélioration symptomatologique et des stratégies d'adaptation selon le traitement. Les traits de personnalité sont particulièrement liés aux résultats thérapeutiques des stratégies actives d'adaptation. Cette thèse contribue à l'avancement des connaissances en se penchant sur l'importance des traits de personnalité dans le traitement psychosocial des jeunes adultes présentant un premier épisode psychotique et en soulignant la nécessité d'étudier davantage les différences individuelles de la personnalité de cette clientèle. Les implications cliniques des résultats et les recommandations pour la recherche sont présentées. / The aim of this thesis was to elucidate the link between personality traits based on the Five Factor Model of personality and therapeutic outcomes of two group treatments for first episode psychosis: cognitive behavior therapy and skills training for symptom management. One hundred and twenty-nine individuals with first episode psychosis were recruited to participate in a randomized controlled trial. Participants were randomized to one of two group treatments or to a wait-list control group. Measures pre- and post-treatment included the shorter version of the Revised NEO personality Inventory (Costa & McCrae, 1992), measures of Brief Psychiatric Rating Scale-Expanded (Lukoff et al., 1986; Ventura et al., 1993) and the shorter version of the Cybernetic Coping Scale coping strategies (Edwards & Baglioni, 1993). In the first article, personality profiles and stability over time of personality traits of individuals with a first episode of psychosis were investigated. Results showed that individuals with a first episode of psychosis present with different personality profiles. Moreover, personality traits of the first episodes showed stability over time. In the second article, personality profiles and predictive value of personality traits or profiles on therapeutic outcomes of treatments for first episode psychosis were investigated. Results revealed also different personality profiles, none specifically linked to psychotic symptoms. No links could be demonstrated between personality traits and symptom improvements but personality traits and profiles were linked to therapeutic improvements in active coping strategies. In the last article, predictive value of personality traits on therapeutic outcomes accordingly to specific group treatments for first episode psychosis was investigated. Results showed links between personality traits, symptoms and coping outcome measures, according to specific group treatments. Personality traits were particularly linked to therapeutic improvements in active coping strategies. In sum, this thesis contributed to the field of personality traits in those with a first episode psychosis by investigating the pertinence of personality traits in the choice of psychosocial treatments and highlighting the need for further study considering individual differences in psychosis. Clinical implications are discussed and recommendations for clinical research offered.

Ce travail porte sur la mesure du couplage pi dans les jonctions Josephson ferromagnétiques à base de Nb et de l'alliage ferromagnétique PdNi. Nous avons mis en oeuvre une expérience de type SQUID (Superconducting QUantum Interfererence Device) avec laquelle nous avons mesuré directement le signe du couplage Josephson - donc la phase supraconductrice - dans les jonctions Josephson Nb/NbOx/PdNi/Nb (SIFS) en fonction de l'épaisseur du PdNi. La présence d'une jonction pi se manifeste par un décalage du spectre de diffraction d'un demi-quantum de flux par rapport au spectre d'un SQUID contenant deux jonctions avec le même signe du couplage Josephson. Nous avons également étudié le couplage Josephson dans des jonctions Nb/PdNi/Nb (SFS) d'une taille de 100*100 um2, ce qui avait pour objectif de mesurer une transition de 0 à pi dans ces jonctions, en fonction de la température. La qualité insuffisante des spectres de diffraction d'une part, et la valeur élevée des courants critiques d'autre part, ne nous ont pas permis de mettre en évidence cette transition. Les problèmes liés à l'impossibilité d'observer cette transition nous ont incitée à développer une nouvelle technique d'évaporation des jonctions à base de membranes en silicium. Ce système permet l'évaporation de jonctions d'une taille de 25*25 um2 in situ, à l'aide de masques, sans recourir à la lithographie optique.

Orientador: Falcondes José Mendes de Seixas / Resumo: O foco principal deste trabalho é a investigação de métodos de controle capazes de rejeitar perturbações, incertezas e influências degenerativas do atraso no problema referente ao controle vetorial por campo orientado do Motor de Indução Trifásico (MIT), através de um modelo matemático não linear deste. Dá-se ênfase à utilização do método de controle Proporcional-Integral em conjunto com o Controle com Estrutura Variável e Modos Deslizantes, sendo que este tem como principal característica a rejeição de perturbações e incertezas. São realizadas análises da robustez da estabilidade e também das influências que as incertezas e atrasos exercem sobre o comportamento dinâmico deste sistema. Para corroborar com as análises, são feitas simulações utilizando exemplos numéricos num sistema linear de ordem dois e aplicações no MIT através de um modelo matemático não linear. / Abstract: This work deals the investigation of control methods capable of rejecting perturbations, uncertainties and degenerative influence of input time-delay in the Three-phase Induction Motor (TIM) vector control problem, through a nonlinear mathematical model. The main focus is the use of the Proportional-Integral control method in conjunction with the Variable Structure Control with Sliding Mode, which has as main characteristic the rejection of perturbations and uncertainties. Analyzes are performed on the stability robustness and also on the influence that the uncertainties and input time-delay on the dynamic behavior of this system. In order to corroborate with the analyzes simulations are made using numerical examples of two-order linear system and applications in a non-linear mathematical model of a Three-phase Induction Motor. / Doutor

La structuration nanométrique par l'auto-assemblage des copolymères à blocs est l'une des stratégies « bottom-up » prometteuses pour contrôler la morphologie de la couche active de cellules photovoltaïques organiques. Dans cette thèse, une nouvelle classe de copolymère constitué d’un bloc semi-conducteur π-conjugué poly(3-hexylthiophène) (P3HT) regioregulier et d’un bloc oligosaccharidique a été synthétisée et a montré une auto-organisation en nanostructures périodiques de domaine inférieure à 10 nm. Deux systèmes de copolymères à blocs ont été synthétisés, le P3HT-bloc-maltoheptaose peracétylé (P3HT-b-AcMal7) et le P3HT-bloc-maltoheptaose (P3HT-b-Mal7), via une réaction de chimie "clic" entre les segments oligosaccharidiques et P3HT fonctionnalisés en extrémité. Une étude exhaustive sur leur comportement d'auto-assemblage par des analyses AFM, TEM et de diffusion des rayons X a révélé que le copolymère à bloc P3HT-b-AcMal7 montre une propension à s'auto-assembler par recuit thermique en structures lamellaires avec une résolution inférieure à 10 nm, c’est-à-dire la morphologie et la taille idéale pour la couche active d’une cellule photovoltaïque organique. De plus, ce système présente l’une des plus petites tailles de domaines réalisées par l'auto-assemblage de copolymères à blocs à base de P3HT. Un réseau lamellaire composé uniquement du P3HT a été obtenu par gravure chimique sélective du bloc sacrificiel AcMal7 à partir d'un film nano-organisé de P3HT-b-AcMal7 et ceci sans affecter la structure lamellaire initiale. Les domaines vides du AcMal7 gravé pourront être remplis par un composé accepteur d'électrons tel que le [6,6]-phényl-C61-butanoate de méthyle (PCBM) pour l’application photovoltaïque comme perspective de cette thèse. Les résultats et les connaissances acquises dans cette étude devraient permettre d'augmenter les performances des prochaines générations de cellules photovoltaïques organiques. / Nanoscale patterning through self-assembly of block copolymers is one of the promising bottom-up strategies for controlling active layer morphology in organic photovoltaics. In this thesis, a new class of carbohydrate-based semiconducting block copolymers consisting of π-conjugated regioregular poly(3-hexylthiophene) (P3HT) and oligosaccharides were synthesized and self-organized into sub-10 nm scale periodic nanostructures. Two different diblock copolymers, i.e. P3HT-block-peracetylated maltoheptaose (P3HT-b-AcMal7) and P3HT-block-maltoheptaose (P3HT-b-Mal7) were synthesized via "click" reaction between end-functionalized oligosaccharide and P3HT moieties. A comprehensive investigation of their self-assembly behavior by AFM, TEM, and X-ray scattering analyses revealed that the P3HT-b-AcMal7 diblock copolymer has the ability to self-assemble into sub-10 nm scale lamellar structure, which is the ideal morphology of the active layer in organic photovoltaics and one of the smallest domain sizes achieved by self-assembly of P3HT-based block copolymers, via thermal annealing. Nano-patterned film made of P3HT was attained by selective chemical etching of AcMal7 block from microphase-separated P3HT-b-AcMal7 template without affecting the original lamellar structure. The resultant void where the etched-out AcMal7 block existed will be filled with electron acceptor compounds such as [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) for photovoltaic application as a perspective of this thesis. The results and knowledge obtained in this study are expected to provide further advances and innovation in organic photovoltaics.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-10-10T15:59:08Z No. of bitstreams: 1 LUCÉLIA NÁRJERA DE ARAÚJO - DISSERTAÇÃO PPGH 2013..pdf: 2054381 bytes, checksum: 803544b6f76d6efd717b1409e3b1843e (MD5) / Made available in DSpace on 2018-10-10T15:59:08Z (GMT). No. of bitstreams: 1 LUCÉLIA NÁRJERA DE ARAÚJO - DISSERTAÇÃO PPGH 2013..pdf: 2054381 bytes, checksum: 803544b6f76d6efd717b1409e3b1843e (MD5) Previous issue date: 2013-04-29 / Neste trabalho analisamos as transformações socioculturais vivenciadas pelos estudantes da FAFI e UFPI em Teresina entre os anos de 1964 a 1975. O recorte temporal foi assim delimitando porque nesse período o Brasil estava vivenciando uma efervescência cultural e ao mesmo tempo um cenário político conturbado marcado pela ditadura militar, que favoreceu a emergência de uma militância estudantil no meio universitário. Desta forma problematizamos como a juventude universitária de Teresina experimentou esses anos e recepcionou novos saberes, práticas, valores e comportamentos diante do discurso disciplinar da ditadura militar e das mudanças culturais que emergiram no período. Para tanto fizemos uma análise da configuração do ensino superior em Teresina. Em seguida, analisamos as táticas de resistência empreendidas pelos jovens para contestar as estratégias dos militares e, por fim como os jovens se conectaram com as novidades que circulavam no Brasil. Metodologicamente utilizamos as fontes hemerográficas pesquisadas no Arquivo Público do Piauí, Arquivo do Jornal O Dia, Arquivo da Cúria Metropolitana. Usamos os jornais O Dia, O Estado e O Dominical, empregamos ainda a metodologia da história oral, coletamos entrevistas de sujeitos que estudaram na FAFI, visando perceber como eles significam sua vivência e experiência desse período. O trabalho está ambientado na História Cultural, tendo como aporte teórico-metodológico Michel de Certeau sua concepção de táticas e estratégias, Roger Chartier a noção de recepção, Halbwachs para pensarmos a questão da memória coletiva. Através desta pesquisa foi possível visualizar as especificidades da militância universitária em Teresina, as lutas e táticas empreendidas pelos estudantes para contestar a ordem estabelecida e os comportamentos juvenis configurados a partir da recepção das mudanças culturais vivenciadas no Brasil. / In this study we analyzed the socio-cultural transformations experienced by students at FAFI and UFPI in Teresina between the years 1964 and 1975. The time frame was thus outlining because in this period Brazil was experiencing a cultural effervescence and, at the same time, a troubled political scenario marked by the military dictatorship that favored the emergence of a student militancy at the universities. Thus it was discussed how the college youth in Teresina experienced these years and welcomed new knowledge, practices, values and behaviors before the disciplinary discourse of military dictatorship and the cultural changes that emerged in the period. Therefore we analyzed the configuration of higher education in Teresina. Then we analyzed the tactics of resistance undertaken by young people to challenge the strategies of the military and ultimately how young people have connected with the news circulating in Brazil. Methodologically we used sources surveyed in the Public Archives of Piaui, O Dia Newspaper Archive, Cúria Metropolitana Archive. We used the newspapers O Dia, O Estado and O Dominical, and also used the methodology of oral history, collected interviews from people who studied at FAFI, aiming to understand how they signify their living and experience of that period. The work is set in the Cultural History, with the theoretical and methodological contribution of Michel de Certeau with his conception of tactics and strategies, Roger Chartier’s notion of reception, and Halbwachs to think through the issue of collective memory. Through this research it was able to see the specifics of the university militancy in Teresina, the struggles and tactics undertaken by students to challenge the established order and the juvenile behavior configured from receipt of the cultural changes experienced in Brazil.

Made available in DSpace on 2011-05-04T12:36:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2010 / A sílica é um composto natural formado pelos dois elementos mais abundantes na Terra - oxigênio e silício. A exposição a partículas de sílica cristalina induz a uma inflamação pulmonar crônica, que pode evoluir para fibrose pulmonar, acarretando na doença conhecida como silicose. O estresse oxidativo desempenha um papel importante na patogênese desta fibrose pulmonar. Sendo assim, a expressão de genes antioxidantes, como glutationa S-transferases (GSTs), são importantes componentes de proteção das células contra o estresse oxidativo e são conhecidas como genes altamente polimórficos, podendo contribuir para a susceptibilidade a silicose. O polimorfismo da GSTP1 A/G resulta na substituição do aminoácido isoleucina por valina, diminuindo, substancialmente, a atividade da enzima GSTP1. O estudo teve como objetivo a determinação do polimorfismo da enzima GSTP1 em trabalhadores expostos à sílica e associação com silicose. A população foi composta por 82 trabalhadores expostos à sílica oriundos, principalmente, da indústria naval. O polimorfismo da GSTP1 foi analisado por PCR-RFLP. Como resultado verificou-se que 31,6 por cento dos trabalhadores tinham genótipo A/A, 57,9 por cento A/G e 10,5 por cento G/G. Observou-se que a média da atividade enzimática da GST foi menor (1,58 U/mL enzima) em indivíduos com o alelo G em relação ao alelo A (1,84 U/mL de enzima). Trabalhadores expostos à sílica portadores do alelo G mostraram um maior risco de desenvolver silicose, embora os resultados não tenham sido significativos, provavelmente, em função do universo amostral. Os indivíduos portadores do alelo G tiveram níveis menores na atividade da GST, independente do genótipo das enzimas GSTM1 e GSTT1. Em conclusão, estudos adicionais devem ser realizados para determinar o polimorfismo da GSTP1 em populações expostas à sílica em comparação com populações não-expostas, pois os resultados deste trabalho sugerem a utilização da determinação do polimorfismo da GSTP1, no processo de avaliação da exposição à sílica, como uma ferramenta complementar na identificação de subgrupos mais susceptíveis ao desenvolvimento da doença silicose. / Sílica is the natural compound of the two most abundant elements on Earth - oxygen and silicon. Exposure to crystalline silica particles induces chronic lung inflammation, which may progress to lung fibrosis, a disease known as silicosis. The oxidative stress plays an important role in the pathogenesis of pulmonary fibrosis. In this respect, the expression of antioxidant genes such as glutathione S-transferases (GSTs) are important to protect cells from oxidative stress and they are known as highly polymorphic genes, that may contribute to silicosis susceptibility. The GSTP1 A G polymorphism results in amino acid substitution isoleucine for valine which substantially diminishes GSTP1 enzyme activity. The objetive of study was the determination of enzyme GSTP1 polymorphism in workers exposed to silica and association with silicosis. The population was composed of 82 workers exposed to silica coming mainly from the shipbuilding industry.GSTP1 polymorphism was analyzed by PCR-RFLP. As a result it was found that 31,6% of workers had genotype A/A, 57,9% A/G and 10.5% G/G. It was observed that the mean enzyme activity of GST was lower (1.58 U / mL enzyme) in individuals with allele G compared with allele A (1.84 U / mL enzyme). Workers exposed to silica with allele G showed a higher risk of developing silicosis, although the results had not been significant, probably because of sample size. Individuals with allele G had lower levels of GST activity, independent of the genotype of GSTM1 and GSTT1 enzymes. In conclusion, further studies to determine the polymorphism of GSTP1 should be conducted in populations exposed to silica compared with non-exposed populations, because the results in this paper suggest the use of the determination of the polymorphism of GSTP1, in the process of evaluating the exposure to silica, as a complementary tool in the identification of subgroups more likely to develop the disease silicosis. / Sílica is the natural compound of the two most abundant elements on Earth - oxygen and silicon. Exposure to crystalline silica particles induces chronic lung inflammation, which may progress to lung fibrosis, a disease known as silicosis. The oxidative stress plays an important role in the pathogenesis of pulmonary fibrosis. In this respect, the expression of antioxidant genes such as glutathione S-transferases (GSTs) are important to protect cells from oxidative stress and they are known as highly polymorphic genes, that may contribute to silicosis susceptibility. The GSTP1 A G polymorphism results in amino acid substitution isoleucine for valine which substantially diminishes GSTP1 enzyme activity. The objetive of study was the determination of enzyme GSTP1 polymorphism in workers exposed to silica and association with silicosis. The population was composed of 82 workers exposed to silica coming mainly from the shipbuilding industry.GSTP1 polymorphism was analyzed by PCR-RFLP. As a result it was found that 31,6% of workers had genotype A/A, 57,9% A/G and 10.5% G/G. It was observed that the mean enzyme activity of GST was lower (1.58 U / mL enzyme) in individuals with allele G compared with allele A (1.84 U / mL enzyme). Workers exposed to silica with allele G showed a higher risk of developing silicosis, although the results had not been significant, probably because of sample size. Individuals with allele G had lower levels of GST activity, independent of the genotype of GSTM1 and GSTT1 enzymes. In conclusion, further studies to determine the polymorphism of GSTP1 should be conducted in populations exposed to silica compared with non-exposed populations, because the results in this paper suggest the use of the determination of the polymorphism of GSTP1, in the process of evaluating the exposure to silica, as a complementary tool in the identification of subgroups more likely to develop the disease silicosis.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-07-22T14:49:45Z No. of bitstreams: 1 CARLOS DAVID DE CARVALHO LOBÃO - DISSERTAÇÃO PPGMAT 2009..pdf: 418073 bytes, checksum: b2deb42599e396408cd91ddf1721d8eb (MD5) / Made available in DSpace on 2018-07-22T14:49:45Z (GMT). No. of bitstreams: 1 CARLOS DAVID DE CARVALHO LOBÃO - DISSERTAÇÃO PPGMAT 2009..pdf: 418073 bytes, checksum: b2deb42599e396408cd91ddf1721d8eb (MD5) Previous issue date: 2009-03 / As álgebras verbalmente primas são bem conhecidas em característica 0. Já sobre corpos de característica p > 2 pouco sabemos sobre elas. Apresentamos modelos genéricos e calcularemos a dimensão de Gelfand-kirillov para as álgebras E⊗E, Aa,b, Ma,b(E)⊗E e Ma,b(E)⊗E. Como consequência, obteremos a prova de não PI-equivalência entre álgebras importantes para PI-Teoria em características positiva. / The verbally prime algebras are well understood in characteristic 0 while over a field of characteristic p > 2 little is known about them. In this work we discuss some sharp differents between these two generics cases for the characteristc. We exhibit constructions of generic models. By using these models we compute the Gelfand-Kirillov dimension of the relatively free algebras of rank m in the varieties generated by E⊗E, Aa,b, Ma,b(E)⊗E e Ma,b(E)⊗E. As consequence we obtain the PI non equivalence of important algebras for the PI theory in positive characteristic.

Pour cette thèse, des systèmes donneur-accepteur (DA) modèles pour le photovoltaïque organique ont été étudiés par microscopie à force atomique en mode non contact (nc-AFM) et microscopie à sonde de Kelvin (KPFM). Ces systèmes DA présentent une structure et des propriétés électroniques mieux contrôlées que dans la plupart des hétérojonctions DA en volume.Afin, d'étudier les propriétés optoélectroniques d'architectures DA présentant une séparation de phase à l'échelle de la dizaine de nanomètres, il est indispensable d'optimiser la résolution des modes nc-AFM/KPFM. Dans ce travail, l'influence du régime d'interaction pointe-surface sur les mesures a été étudiée dans le cas d'auto-assemblages de P3DDT sur substrat HOPG. Nous avons ainsi démontré que l'imagerie dans le régime d'interaction à courte portée améliore non seulement la résolution latérale, mais permet également de réaliser des mesures de hauteur plus réalistes.Ensuite, un système DA à base de FG1:[70]PCBM a été étudié. Pour ce mélange DA, la nanostructure et l'échelle de la séparation de phase peuvent être ajustées grâce aux propriétés cristal liquide du composé donneur FG1. Les potentiels mesurés dans le noir sont consistants avec la morphologie attendue en surface et en volume. La relation entre le photo-potentiel de surface (SPV) et le régime d'interaction pointe-surface a pu être précisément analysée. Une résolution optimale est obtenue dans les images de SPV en travaillant près du seuil de dissipation.Enfin, une nouvelle génération de diades comprenant des groupements donneur et accepteur a été étudiée. La nature de l'auto-assemblage sur HOPG a été établie sur la base d'études comparatives de microscopie à effet tunnel et de nc-AFM, avec le support de simulations en mécanique et dynamique moléculaire. Les mesures de photo-potentiel de surface ont ensuite permis de démontrer qu'il était possible d'étudier les mécanismes de photo-génération des porteurs jusqu'à l'échelle de la mono-couche moléculaire. / During this thesis, model donor-acceptor (DA) systems for organic photovoltaics have been studied by non-contact atomic force microscopy (nc-AFM) and Kelvin probe force microscopy (KPFM). To enhance the understanding of the optoelectronic processes on the nanoscale, DA systems with better defined structural and electronic properties than the one of most bulk heterojunction blends (BHJ), have been studied.With DA phase-separations of below 10nm in organic photovoltaic systems, the highest possible resolution has to be achieved by KPFM to investigate optoelectronic processes. It has been shown that nc-AFM/KPFM measurements in the regime of short range (SR) forces can increase imaging resolution. In preparation of such investigations, the influence of the interaction regime on the topographic measurement via KPFM has been studied for a self-assembly of P3DDT on HOPG. It is demonstrated that imaging in the SR-regime not only increases the lateral resolution, but also assures a correct topographic height values.In a next step, DA blends of FG1:[70]PCMB have been studied by KPFM. For these BHJs, the structure and the scale of the DA phase-separation can be tuned via the liquid crystal behavior of the donor FG1. The in dark potential contrasts are consistent with surface and bulk morphology. The relationship between the surface photovoltage (SPV) and the tip-sample interaction regime has been analyzed. An optimal resolution for SPV imaging is obtained when measuring next to the onset of dissipation.Finally, a new generation of DA dyad with donor and acceptor moieties has been studied. Its self-assembly on HOPG has been determined via a comparative study by scanning tunneling microscopy and nc-AFM plus molecular mechanics and dynamics simulations. By KPFM the charge carrier generation and collection has been analyzed down to the level of a single molecular layer. A clear relationship between the dyads' molecular assembly and their photovoltaic properties can be established.

Submitted by Maria Suzana Diniz (msuzanad@hotmail.com) on 2015-11-12T13:26:59Z No. of bitstreams: 1 arquivototal.pdf: 1771439 bytes, checksum: 5a0ce436783e1a04419dc8a73bf4c204 (MD5) / Made available in DSpace on 2015-11-12T13:26:59Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1771439 bytes, checksum: 5a0ce436783e1a04419dc8a73bf4c204 (MD5) Previous issue date: 2015-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work presents the designs and results obtained through simulation and experimental testing of conventional controllers P, PI and PID implemented by personal computers applied to an electropneumatic servomechanism for control of force. The system consists of a double acting pneumatic cylinder, which is responsible for applying the force on a mechanical subsystem consisting of a spiral spring, representing the means of working. The proportional electropneumatic flow valve, being the element controlling the flow of compressed air to be released into the pneumatic air cylinder which results in controlled force application; a load cell converts the force applied by the cylinder onto the medium into an electrical signal. The control signal to be applied on the electropneumatic proportional flow valve comes from a signal input and output plate installed on the computer, which is controlled by an algorithm implemented in the computing environment LabVIEW®, wherein the mentioned controllers are inserted, the mathematical representative model of the servomechanism was obtained by applying the parametric identification technique Box-Jenkins (BJ) which results in a family of four models, one of which is chosen to represent the system. The adjustment of the controllers is done by using the critical gain method of Ziegler and Nichols so that the response from the system meets the performance specifications imposed on it. Simulated and experimental results of the system are presented under the inserted controllers, which are analyzed according to relevant theory to the study of conventional controllers; it appears then that the PID controller is best suited for use in its electropneumatic servomechanism. / Neste trabalho apresenta-se os projetos e resultados obtidos através de simulações e ensaios experimentais de controladores convencionais P, PI e PID implementado por computador pessoal aplicado em um servomecanismo eletropneumático para controle de força. O sistema é constituído por um cilindro pneumático de dupla ação, sendo este responsável pela aplicação da força sobre um subsistema mecânico constituído por uma mola helicoidal, representando o meio de trabalho. A válvula eletropneumática proporcional de vazão, sendo o elemento de controle da vazão de ar comprimido a ser liberada para o cilindro pneumático que resulta na aplicação da força controlada; uma célula de carga converte a força aplicada pelo cilindro sobre o meio em sinal elétrico. O sinal de controle a ser aplicado na válvula eletropneumática proporcional de vazão é proveniente de uma placa de entrada e saída de sinais instalada no computador, sendo esta comandada por um algoritmo implementado no ambiente computacional LabVIEW®, no qual os referidos controladores estão inseridos. O modelo matemático representativo do servomecanismo foi obtido aplicando-se a técnica de identificação paramétrica Box-Jenkins (BJ) da qual resulta uma família de quatro modelos, dos quais um é escolhido para representar o sistema. O ajuste dos controladores é feito utilizando-se a técnica do ganho crítico de Ziegler e Nichols, de modo que a resposta do sistema atenda as especificações de desempenho impostas ao mesmo. Resultados simulados e experimentais do sistema são apresentados sob ação dos controladores inseridos, que são analisados de acordo com a teoria pertinente ao estudo dos controladores convencionais; verifica-se então que o controlador PID é o mais adequado para utilização no respectivo servomecanismo.

Made available in DSpace on 2015-03-03T15:07:34Z (GMT). No. of bitstreams: 1 AndreFOAD_DISSERT.pdf: 2002320 bytes, checksum: 0ebf2e7fb75a8ce59284dc72a43ef7ba (MD5) Previous issue date: 2012-05-18 / The separation methods are reduced applications as a result of the operational costs, the low output and the long time to separate the uids. But, these treatment methods are important because of the need for extraction of unwanted contaminants in the oil production. The water and the concentration of oil in water should be minimal (around 40 to 20 ppm) in order to take it to the sea. Because of the need of primary treatment, the objective of this project is to study and implement algorithms for identification of polynomial NARX (Nonlinear Auto-Regressive with Exogenous Input) models in closed loop, implement a structural identification, and compare strategies using PI control and updated on-line NARX predictive models on a combination of three-phase separator in series with three hydro cyclones batteries. The main goal of this project is to: obtain an optimized process of phase separation that will regulate the system, even in the presence of oil gushes; Show that it is possible to get optimized tunings for controllers analyzing the mesh as a whole, and evaluate and compare the strategies of PI and predictive control applied to the process. To accomplish these goals a simulator was used to represent the three phase separator and hydro cyclones. Algorithms were developed for system identification (NARX) using RLS(Recursive Least Square), along with methods for structure models detection. Predictive Control Algorithms were also implemented with NARX model updated on-line, and optimization algorithms using PSO (Particle Swarm Optimization). This project ends with a comparison of results obtained from the use of PI and predictive controllers (both with optimal state through the algorithm of cloud particles) in the simulated system. Thus, concluding that the performed optimizations make the system less sensitive to external perturbations and when optimized, the two controllers show similar results with the assessment of predictive control somewhat less sensitive to disturbances / Os m?todos de separa??o de ?leo e ?gua possuem, em sua maioria, aplica??es reduzidas devido ao custo operacional, a baixa efici?ncia de separa??o e ao alto tempo de processamento da separa??o. Por?m, Esses m?todos de tratamento s?o importantes devido a necessidade de extra??o dos contaminantes mais indesejados no processo de produ??o do petr?leo, a ?gua, e ao mesmo tempo, a concentra??o de ?leo na ?gua deve ser m?nima (da ordem de 40 a 20ppm) para o descarte regular da fase aquosa ao mar. A partir dessa necessidade de tratamento prim?rio objetiva-se, neste trabalho, estudar e implementar algoritmos de identifica??o para modelos polinomiais NARX em malha fechada, detectando a estrutura dos modelos, e comparar estrat?gias de controle PI e preditivo utilizando os modelos NARX (Nonlinear Auto-Regressive with Exogenous Input) atualizados online em uma combina??o de separador trif?sico em s?rie com tr?s baterias de hidrociclones. Os objetivos principais deste trabalho s?o obter um processo otimizado de separa??o trif?sica que regule o sistema, mesmo na presen?a de golfadas; mostrar que e poss?vel obter sintonias otimizadas para os controladores analisando a malha como um todo; e, avaliar e comparar as estrat?gias de controle PI e preditivo aplicadas ao processo. Para cumprir estes objetivos foi utilizado um simulador para representar o separador trif?sico e os hidrociclones, al?m de desenvolvidos algoritmos de identifica??o de sistemas (NARX) utilizando MQR (M?nimos Quadrados Recursivo), aliados a m?todos de detec??o de estrutura de modelos. Tamb?m foram implementados algoritmos de controle preditivo com modelos NARX atualizados online, e algoritmos de otimiza??o que utilizam PSO (Particle Swarm Optimization). O trabalho finaliza com a compara??o de resultados obtidos a partir da utiliza??o dos controladores PI e preditivo no sistema simulado ambos com par?metros otimizados atrav?s do algoritmo de nuvem de part?culas, e concluindo que as otimiza??es realizadas tornam o regulat?rio menos sens?vel a perturba??es externas (golfadas) e quando otimizados os dois controladores apresentam resultados similares, sendo os resultados do preditivo um pouco menos sens?vel as perturba??es