Els materials nanocristal·lins han esdevingut darrerament un dels camps de recerca més actius en l'àrea de la Ciència de Materials. Aquest tipus de materials, caracteritzats per la presència d'estructures organitzades de tamanys característics entre el nm i el mm, han mostrat en determinats casos noves propietats, a vegades sorprenents, diferents dels materials tradicionals de composicions similars. Una característica comuna d'aquests materials és que les propietats que poden resultar d'interès són dependents, de vegades críticament, de la grandària de les nanostructures. El present treball es centra en aquesta temàtica, dins d'un subgrup de materials nanoestructurats molt concret com són els obtinguts mitjançant transformacions sòlid-sòlid activades tèrmicament. Un exemple d'aquests materials són els vidres metàl·lics nanocristal·litzats mitjançant un tractament tèrmic. Aquestes transformacions segueixen majoritàriament cinètiques de nucleació i creixement, el comportament cinètic de les quals és raonablement ben conegut des de la dècada de 1940 (models de Kolmogorov, Johnson & Mehl i Avrami, KJMA). L'objectiu fonamental del treball és generalitzar el model d'evolució microestructural PKJMA, desenvolupat anteriorment pel grup de recerca al que pertany l'autor, i oferir un esquema robust d'àmplia aplicabilitat. Aquest objectiu s'ha assolit, donant lloc a un sistema d'equacions contínues d'evolució per la distribució de grandària de gra, aplicable als materials nanocristal·lins obtinguts en condicions de laboratori. La validesa d'aquestes equacions s'ha comprovat amb la comparació amb simulacions cinètiques de creixement en condicions controlades. Una segona part del treball es centre en l'estudi dels efectes d'una nucleació no aleatòria en aquestes transformacions. El fet que aquest fenòmen sol considerar-se present a la cristal·lització primària de vidres metàl·lics va augmentar l'interès sobre el tema, i conduí, primer, a simular cinèticament aquest fenòmen i, després, a buscar un model adequat per descriure les desviacions observades respecte la cinètica KJMA. La construcció d'aquest model és el pas previ per l'extensió del model d'evolució microestructural a aquests sistemes.

A diferencia de la importancia de las investigaciones que, tradicionalmente, han dado protagonismo al mundo andino, son muy pocos los estudios que, desde el ámbito disciplinario de la historia, han abordado los territorios y las sociedades de las denominadas tierras bajas. En Bolivia, esto significa referirse, fundamentalmente, a la Amazonía que era percibida como “tierras baldías”, sin dueño, al margen de la civilización y susceptibles de ser ocupadas. En este sentido, desde mediados del siglo XIX, la amazonía boliviana pasó a ser administrada por el recién creado departamento del Beni, cuya historia sólo ha sido abordada recientemente y focalizada en acontecimientos del siglo XX. No obstante, se desconocen los aspectos más significativos de la historia socioeconómica y política del Beni durante la etapa de construcción de Bolivia como estado-nación siendo el estudio de este proceso el objetivo general de la tesis. Entendiendo que la conformación y consolidación del estado boliviano pasaba por el control de la amazonía, este trabajo aborda los avances y retrocesos producidos en el proceso de construcción del departamento del Beni, a través de las distintas políticas desarrolladas por el Estado. Ello ha permitido comprender los aspectos más importantes de la región beniana desde 1842, año de la creación del departamento, hasta el establecimiento definitivo de sus límites interestatales e interdepartamentales, en 1938. Así, se han analizado los programas y disposiciones estatales que pretendían nacionalizar la amazonía, siendo de especial interés aquellas que perseguían la exploración y colonización del territorio, la organización político-administrativa del departamento y su definición jurisdiccional; se han considerado también las relaciones, actitudes y prácticas desarrolladas por los grupos dirigentes, los grupos de poder local y regional y las poblaciones indígenas en el ejercicio de sus derechos y el acceso a las cotas de poder político y económico, que permitieron la construcción de la sociedad regional; y, finalmente, se han identificado las principales transformaciones de carácter socioeconómico de la región y, por ende, en la gestión de los recursos naturales y la tierra. Los principales aportes de esta investigación radican en la disección de las políticas estatales relativas hacia el Beni, y el uso y apropiación de éstas por parte de la sociedad local (blanco-mestiza e indígena) en el contexto de construcción del estado-nación boliviano. De ello se desprende que la construcción del departamento y de la sociedad beniana fue posible, fundamentalmente, por el control privado de los recursos naturales y económicos -tierras, ganadería, bosques- existentes en la región por parte de los actores locales y regionales en detrimento, en la mayor parte de las ocasiones, del Estado y también de las poblaciones indígenas. En fin, consideramos que la investigación realizada muestra la incapacidad de todos los gobiernos bolivianos para desarrollar sus políticas orientalistas –defensa de la soberanía, colonización del territorio, etc.- siendo lo acontecido en el Beni, buen indicador de la debilidad e incapacidad de los dirigentes bolivianos para incorporar la amazonía a la república a lo largo del siglo XIX e inicios del siglo XX. / “For a history of Beni. A socioeconomic, political and ideological study of the Bolivian Amazon, centuries XIX-XX.” SUMMARY: There are very few studies that approach, from the discipline of history, to the territories and the societies of the lowlands. In Bolivia, refers principally to the Amazon, perceived as "the uncultivated lands" that must be occupied. From the middle of 19th century, the Bolivian Amazon was administrated by the department of Beni, whose history in the republican era has been poorly approached. Thus, the general aim of this thesis is the study of the most significant political and socioeconomic aspects of the history of Beni during the construction of Bolivia as nation-state. The control of the Amazon was basic for the consolidation of the Bolivian nation-state. Through diverse policies developed by the State, this thesis examines the progress and setbacks in the construction of the department of Beni, since 1842, the year of the department’s creation, until the final demarcation of their borders in 1938. It analyzes the government programs and regulations that wanted to nationalize the Amazon through the exploration and colonization of the territory, political and administrative organization of the department of Beni and its jurisdiction. Also considers the relationships, attitudes and practices developed by the local and regional groups and indigenous peoples in the exercise of their rights and access to political positions and economic power. And finally, identifies the main socioeconomic transformations in the region and in the management of natural resources and land. The main contributions of this research are in the dissection of state policies concerning the Beni, and the use and the appropriation of them by local society (white-mestizo and indigenous) in the context of construction of the Bolivian nation-state. Thus, the construction the department of Beni and their society was possible mainly by the private control of natural and economic resources of the region -land, livestock and forests- by local and regional groups against, in occasions, the State and indigenous populations. In short, the history of Beni shows the weakness and inability of Bolivian leaders to incorporate the Amazon to the republic during the 19th and early 20th century.

En aquesta tesi es valora l'impacte social que comporta per a la ciutat de Vic el bastiment d'un nou sistema educatiu implantat per l'estat liberal en el transcurs del segle XIX. L'estudi s'estructura a partir de: l'anàlisi del discurs i de les accions de les elits locals; de les actituds de les famílies; del sorgiment i consolidació dels i les mestres; i de l'escola com a espai educatiu: Vic esdevé un cas molt particular perquè és capital de bisbat però no de província; perquè exerceix una notable influència sobre el territori i perquè és zona de frontera entre el liberalisme i el carlisme. La tesi valora fins a quin punt tots els agents implicats en la qüestió educativa s'interconecten i com des de l'àmbit local es viuen les transformacions del segle XIX. / The present thesis evaluates the social impact on the city of Vic caused by the implementation of a new education system introduced by the liberal state during the 19th century. The study is structured from: the analysis of the discourse and the actions by local elites; the attitudes of the families; the rise and consolidation of teachers; and the school as a space for education: Vic becomes a very particular case because it is the bishopric capital city but not the province capital; and because it has a notable influence on the territory and it is a border between liberalism and Carlism. The thesis assesses to what extent all agents implied in the education issue are interconnected and how the transformations of the 19th century are viewed from the local environment.

Made available in DSpace on 2014-12-17T14:52:38Z (GMT). No. of bitstreams: 1 LucianaMO.pdf: 4073489 bytes, checksum: 4335a902162ee646b1b51eab4a321659 (MD5) Previous issue date: 2008-08-29 / The present work is grounded basically on the use of the Basic Tools for the Statistic Process Control SPC, with the intent to detect non-conformities on a given productive process. It consists on a case study accomplished at a Hemocenter in Natal (Rio Grande do Norte). In this study it is shown that, the Statistic Process Control Technique, which was used as a tool, is useful to identify on-conformities on the volume of hemocomponents. The gathering of the used data was performed by means of document analysis, direct observations and database queries. The results achieved from the study show that the analyzed products, even though when they have presented, in some cases, points out of control, they satisfied the ANVISA standards. Finally, suggestions for further improvement of the final product and guidance for future employment of CEP, also extended to other lines of production, are presented / A presente disserta??o fundamenta-se, basicamente, na utiliza??o das Ferramentas B?sicas do Controle Estat?stico do Processo CEP, com o objetivo de detectar n?o conformidades num determinado processo produtivo. Trata-se de um estudo de caso, realizado em um Hemocentro, no munic?pio de Natal (Rio Grande do Norte). Demonstra-se no estudo que a t?cnica do controle estat?stico do processo, utilizada como ferramenta, ? ?til para identificar n?o conformidades no volume dos hemocomponentes. A coleta dos dados utilizados se deu atrav?s de: an?lise documental, observa??es diretas e consultas ao banco de dados. Os resultados do estudo demonstram que os produtos analisados, mesmo apresentando, em alguns casos, pontos fora de controle, satisfaziam as normas da ANVISA. Finalmente, s?o apresentadas sugest?es para melhorar ainda mais o produto final e tamb?m orientar a futura implanta??o do CEP, inclusive em outras linhas de produ??o

Made available in DSpace on 2014-12-17T14:52:39Z (GMT). No. of bitstreams: 1 PaulaOF.pdf: 1749658 bytes, checksum: c5a7f0123f17bea5eee66bccfbc7edd0 (MD5) Previous issue date: 2008-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This Master Thesis presents a case study on the use of Statistical Process Control (SPC) at the N?cleo de Pesquisas em Alimentos e Medicamentos (NUPLAM). The SPC basic tools have been applied in the process of the tuberculost?ticos drugs encapsulation, primarily concerning the objective to choose, between two speeds, which one is the best one to perform the tuberculostatics encapsulation. Later on, with the company effectively operating, the SPC was applied intending to know the variability of the process and, through the tracking of the process itself, to arrive at an estimated limit for the control of future lots of tuberculostatics of equal dosage. As special causes were detected acting in the process, a cause-and-effect diagram was built in order to try to discover, in each factor that composes the productive process, the possible causes of variation of the capsules average weight. The hypotheses raised will be able to serve as a base for deepened the study to eliminate or reduce these interferences in the process. Also a study on the capacity of the process to attend the specifications was carried out, and this study has shown the process?s inaptitude to take care of them. However, on the side of NUPLAM exists a real yearning to implant the SPC and consequently to improve the existing quality already present on its medicines / Esta disserta??o apresenta um estudo de caso sobre a utiliza??o do Controle Estat?stico do Processo (CEP) no N?cleo de Pesquisas em Alimentos e Medicamentos (NUPLAM). As ferramentas b?sicas do CEP foram aplicadas no processo de encapsulamento de tuberculost?ticos primeiramente com o objetivo de escolher entre duas velocidades qual a melhor para a realiza??o do encapsulamento dos tuberculost?ticos. Posteriormente, com a empresa efetivamente funcionando, o CEP foi aplicado com o intuito de conhecer a variabilidade do processo e atrav?s do monitoramento do mesmo chegar a um limite de controle estimado para o controle de lotes futuros de tuberculost?ticos que possuam a mesma dosagem do tuberculost?tico monitorado. Como foram detectadas causas especiais atuando no processo, um diagrama de causa-e- efeito foi constru?do a fim de tentar descobrir em cada fator que comp?e o processo produtivo as poss?veis causas de varia??o do peso m?dio das c?psulas. As hip?teses levantadas poder?o servir de base para um estudo mais aprofundado para a elimina??o ou redu??o dessas interfer?ncias no processo. Tamb?m foi realizado um estudo sobre a capacidade do processo em atender ?s especifica??es o qual se mostrou incapaz de atend?-las. Contudo, existe por parte do NUPLAM um real anseio em implantar o CEP e conseq?entemente melhorar a qualidade j? existente em seus medicamentos

Made available in DSpace on 2015-03-03T15:16:25Z (GMT). No. of bitstreams: 1 AlysonPS_TESE.pdf: 964551 bytes, checksum: c9d496a0da4f410a6e8efa100d961e64 (MD5) Previous issue date: 2012-03-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Considering a quantum gas, the foundations of standard thermostatistics are investigated in the context of non-Gaussian statistical mechanics introduced by Tsallis and Kaniadakis. The new formalism is based on the following generalizations: i) Maxwell- Boltzmann-Gibbs entropy and ii) deduction of H-theorem. Based on this investigation, we calculate a new entropy using a generalization of combinatorial analysis based on two different methods of counting. The basic ingredients used in the H-theorem were: a generalized quantum entropy and a generalization of collisional term of Boltzmann equation. The power law distributions are parameterized by parameters q;, measuring the degree of non-Gaussianity of quantum gas. In the limit q ?1; ?0, the gaussian thermostatistics is recovered. A complementary study is related to a perfect gas in the context of general relativity. Using the non-Gaussian effects on the concept of entropy flux, and on the collisional term of the Boltzmann equation, we generalize the H-theorem within the Tsallis and Kaniadakis frameworks. In the first one, the nonextensive parameter is constrained to the interval [0,2] / Considerando um g?s qu?ntico, os fundamentos da termoestat?stica padr?o s?o investigados no contexto da mec?nica estat?stica n?o-gaussiana introduzida por Tsallis e Kaniadakis. O novo formalismo ? baseado nas seguintes generaliza??es: i) entropia de Maxwell-Boltzmann-Gibbs e ii) dedu??o do Teorema-H. Com base neste estudo, calculamos uma nova entropia usando a generaliza??o da an?lise combinat?ria baseadas em dois diferentes m?todos de contagem. Os ingredientes b?sicos usados no teorema-H foram: uma entropia qu?ntica generalizada e uma generaliza??o do termo colisional da equa??o de Boltzmann. As distribui??es lei de pot?ncia calculadas s?o parametrizadas pelos par?metros q; , medindo o grau de n?o-gaussianidade do sistema. No limite q ?1; ?0, a termoestat?stica gaussiana ? recuperada. Um estudo complementar est? relacionado com um g?s perfeito no contexto da relatividade geral. Utilizando os efeitos n?o-gaussiano no conceito de fluxo de entropia, e no termo colisional da equa??o de transporte de Boltzmann, n?s generalizamos o teorema- H nos formalismos de Tsallis e Kaniadakis. No formalismo de Tsallis, o par?metro n?o extensivo est? restrito ao intervalo [0,2]

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-02T22:55:04Z No. of bitstreams: 1 GiselleKallineGomesCarvalho_DISSERT.pdf: 2257540 bytes, checksum: e731412b34e93ab422b0df96d21ad8b7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-04T00:24:44Z (GMT) No. of bitstreams: 1 GiselleKallineGomesCarvalho_DISSERT.pdf: 2257540 bytes, checksum: e731412b34e93ab422b0df96d21ad8b7 (MD5) / Made available in DSpace on 2016-03-04T00:24:44Z (GMT). No. of bitstreams: 1 GiselleKallineGomesCarvalho_DISSERT.pdf: 2257540 bytes, checksum: e731412b34e93ab422b0df96d21ad8b7 (MD5) Previous issue date: 2014-11-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Atividades industriais de minera??o, galvanoplastia e o processo de extra??o do petr?leo, vem aumentando os n?veis de metais pesados, tais como Cu, Fe, Mg e Cd, nos ecossistemas aqu?ticos. Este aumento est? relacionado ao descarte de efluentes contendo teores desses elementos acima do valor m?ximo permitido por lei. M?todos como troca i?nica, filtra??o por membranas e precipita??o qu?mica vem sendo estudados como meios de tratamentos de efluentes contaminados por esses metais. A precipita??o de metais utilizando tensoativos ani?nicos obtidos a partir de ?cidos carbox?licos surgiu como uma alternativa para a remo??o de metais de efluentes industriais. A rea??o entre ?ons bivalentes dos metais e esses tipos de tensoativos em solu??o aquosa leva a forma??o de carboxilatos de metais, que podem precipitar na forma de flocos e serem removidos, posteriormente, por um processo de decanta??o dos flocos formados ou por uma filtra??o simples. Neste trabalho, a extra??o de metais ? realizada por meio da utiliza??o do tensoativo hexadecanoato de s?dio como agente extrator. O objetivo principal ? estudar o efeito da varia??o da temperatura do meio, pH da solu??o de metal e concentra??o do tensoativo no processo de remo??o do metal. A modelagem estat?stica do estudo mostrou que o processo ? diretamente dependente das varia??es de pH e concentra??o do tensoativo, por?m inversamente proporcional e pouco dependente da varia??o de temperatura, sendo esse ?ltimo efeito considerado desprez?vel na maioria dos casos. O estudo individual do efeito da temperatura apresenta uma forte depend?ncia do processo ? temperatura de Kraft, tanto do tensoativo utilizado como agente extrator como do tensoativo obtido ap?s a rea??o desse tensoativo com o metal. A partir dos dados de temperaturas e concentra??es do tensoativo foi poss?vel o c?lculo da constante de equil?brio para a rea??o entre o hexadecanoato de s?dio e ?ons cobre. Posteriormente, foram determinados par?metros termodin?micos, comprovando que o processo ? exot?rmico e espont?neo. / Industrial activities like mining, electroplating and the oil extraction process, are increasing the levels of heavy metals such as Cu, Fe, Mg and Cd in aquatic ecosystems. This increase is related to the discharge of effluents containing trace of this elements above the maximum allowed by law. Methods such as ion exchange, membrane filtration and chemical precipitation have been studied as a means of treatment of these metals contamination. The precipitation of metals using anionic surfactants derived from carboxylic acids emerged as an alternative for the removal of metals from industrial effluents. The reaction between bivalent ions and these types of surfactants in aqueous solution leads to the formation of metal carboxylates, which can precipitate in the form of flakes and are subsequently removed by a process of decantation or simple filtration. In this work the metals extraction is performed by using the surfactant sodium hexadecanoate as extracting agent. The main purpose was to study the effect of temperature, solution pH, and concentration of surfactant in the metal removal process. The statistical design of the process showed that the process is directly dependent to changes in pH and concentration of surfactant, but inversely proportional and somewhat dependent to temperature variation, with the latter effect being considered negligible in most cases. The individual study of the effect of temperature showed a strong dependence of the process with the Kraft point, both for the surfactant used as extracting agent, as for the surfactant obtained after the reaction of this surfactant with the metal. From data of temperatures and concentrations of the surfactant was possible to calculate the equilibrium constant for the reaction between sodium hexadecanoate and copper ions. Later, thermodynamic parameters were determined, showing that the process is exothermic and spontaneous.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-31T23:35:39Z No. of bitstreams: 1 RodrigoDaSilvaSobrinho_DISSERT.pdf: 2479618 bytes, checksum: 3094f42c505921ebc1ac094112499a49 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-05T20:34:51Z (GMT) No. of bitstreams: 1 RodrigoDaSilvaSobrinho_DISSERT.pdf: 2479618 bytes, checksum: 3094f42c505921ebc1ac094112499a49 (MD5) / Made available in DSpace on 2016-04-05T20:34:51Z (GMT). No. of bitstreams: 1 RodrigoDaSilvaSobrinho_DISSERT.pdf: 2479618 bytes, checksum: 3094f42c505921ebc1ac094112499a49 (MD5) Previous issue date: 2015-05-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O pioneiro trabalho proposto por Skumanich (1972) mostrou que a velocidade de rota?c?ao projetada m?edia < v sini > para estrelas do tipo solar obedece uma lei de decrescimento no tempo, dada por t ?1/2 , onde t ?e a idade da estrela. Essa rela?c?ao ?e consistente com as teorias de perda de momentum angular atrav?es do vento estelar ionizado, que por sua vez est?a acoplado `a estrela pelo seu campo magn?etico. V?arios autores (e.g.: Silva et al. 2013 e de Freitas et al. 2014) analisaram as poss??veis correla?c?oes entre o decaimento rotacional e o perfil da distribui?c?ao de velocidade. Esses autores chegaram a uma simples rela?c?ao heur??stica, mas n?ao constru??ram uma passagem direta entre o expoente do decaimento rotacional (j) e o expoente da distribui?c?ao da velocidade rotacional (q). Todo esse cen?ario te?orico foi proposto usando uma eficiente e robusta mec?anica estat??stica bem conhecida como mec?anica estat??stica n?ao-extensiva. A presente disserta?c?ao prop?oe efetivamente fechar essa quest?ao, elaborando um caminho te?orico para modificar as distribui?c?oes q-Maxwellianas em q-Maxwellianas com v??nculos f??sicos extra??dos da teoria do freio magn?etico. Para testar nossas distribui?c?oes, usamos um pacote de dados do cat?alogo de Geneva-Copenhagem Survey com aproximadamente 6000 estrelas F e G limitadas em idade. Como resultado, obtivemos que os expoentes da lei de decaimento e da distribui?c?ao seguem uma rela?c?ao similar `aquela proposta por Silva et al. (2013). / The pioneering work proposed by Skumanich (1972) has shown that the projected mean rotational velocity < v sini > for solar type stars follows a rotation law decreases with the time given by t ?1/2 , where t is the stellar age. This relationship is consistent with the theories of the angular momentum loss through the ionized stellar wind, which in turn is coupled to the star through its magnetic field. Several authors (e.g.: Silva et al. 2013 and de Freitas et al. 2014) have analyzed the possible matches between the rotational decay and the profile of the velocity distribution. These authors came to a simple heuristic relationship, but did not build a direct path between the exponent of the rotational decay (j) and the exponent of the distribution of the rotational velocity (q). The whole theoretical scenario has been proposed using an efficient and strong statistical mechanics well known as non-extensive statistical mechanics. The present dissertation proposes effectively to close this issue by elaborating a theoretical way to modify the q-Maxwellians? distributions into q-Maxwellians with physics links extracted from the theory of magnetic braking. In order to test our distributions we have used the GenevaCapenhagen Survey data with approximately 6000 F and G field stars limited by age. As a result, we obtained that the exponents of the decay law and distribution follow a similar relationship to that proposed by Silva et al. (2013).

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-31T23:54:17Z No. of bitstreams: 1 RenatoTigreMartinsDaCosta_DISSERT.pdf: 1398473 bytes, checksum: 5259c2bb8b8df69f928b864b5cdaf972 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-05T22:15:41Z (GMT) No. of bitstreams: 1 RenatoTigreMartinsDaCosta_DISSERT.pdf: 1398473 bytes, checksum: 5259c2bb8b8df69f928b864b5cdaf972 (MD5) / Made available in DSpace on 2016-04-05T22:15:41Z (GMT). No. of bitstreams: 1 RenatoTigreMartinsDaCosta_DISSERT.pdf: 1398473 bytes, checksum: 5259c2bb8b8df69f928b864b5cdaf972 (MD5) Previous issue date: 2015-04-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Este trabalho prop?e um gr?fico de controle modificado incorporando conceitos de an?lise de s?ries temporais. Especificamente, n?s consideramos os modelos de distribui??o de transi- ??o e mistura gaussianas (GMTD). Os modelos GMTD s?o uma classe mais geral do que os modelos da fam?lia autoregressiva (AR), no sentido de que os processos autocorrelacionados podem apresentar trechos planos (plat?s), explos?es ou outliers. Neste cen?rio os Gr?ficos de Shewhart tradicionais n?o s?o mais ferramentas adequadas para o acompanhamento desses processos. Portanto, Vasilopoulos e Stamboulis (1978) propuseram uma vers?o modificada dos gr?ficos, considerando limites de controle adequados com base em processos autocorrelacionados. A fim de avaliar a efici?ncia da t?cnica proposta uma compara??o com um gr?fico tradicional Shewhart (que ignora a estrutura de autocorrela??o do processo), o gr?fico de controle Shewhart AR(1) e um gr?fico de controle Shewhart GMTD foi feita. Uma express?o anal?tica para a vari?ncia processo, assim como os limites de controle foram desenvolvidos para um modelo GMTD particular. O ARL ? utilizado como crit?rio para medir a efici?ncia dos gr?ficos de controle. A compara??o foi feita com base em uma s?rie gerada de acordo com um modelo GMTD. Os resultados apontam para a dire??o que os gr?ficos modificados Shewhart GMTD t?m um melhor desempenho do que o Shewhart AR(1) e o Shewhart tradicional. / This work proposes a modified control chart incorporating concepts of time series analysis. Specifically, we considerer Gaussian mixed transition distribution (GMTD) models. The GMTD models are a more general class than the autorregressive (AR) family, in the sense that the autocorrelated processes may present flat stretches, bursts or outliers. In this scenario traditional Shewhart charts are no longer appropriate tools to monitoring such processes. Therefore, Vasilopoulos and Stamboulis (1978) proposed a modified version of those charts, considering proper control limits based on autocorrelated processes. In order to evaluate the efficiency of the proposed technique a comparison with a traditional Shewhart chart (which ignores the autocorrelation structure of the process), a AR(1) Shewhart control chart and a GMTD Shewhart control chart was made. An analytical expression for the process variance, as well as control limits were developed for a particular GMTD model. The ARL was used as a criteria to measure the efficiency of control charts. The comparison was made based on a series generated according to a GMTD model. The results point to the direction that the modified Shewhart GMTD charts have a better performance than the AR(1) Shewhart and the traditional Shewhart.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-07T00:04:50Z No. of bitstreams: 1 FernandoJoseVieiraDaCunhaFilho_DISSERT.pdf: 1842958 bytes, checksum: 2191a99f87d6cfed0a71cb2a9466d014 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-09T20:31:23Z (GMT) No. of bitstreams: 1 FernandoJoseVieiraDaCunhaFilho_DISSERT.pdf: 1842958 bytes, checksum: 2191a99f87d6cfed0a71cb2a9466d014 (MD5) / Made available in DSpace on 2016-05-09T20:31:23Z (GMT). No. of bitstreams: 1 FernandoJoseVieiraDaCunhaFilho_DISSERT.pdf: 1842958 bytes, checksum: 2191a99f87d6cfed0a71cb2a9466d014 (MD5) Previous issue date: 2015-08-25 / A perfura??o de po?os de petr?leo, uma das etapas da explora??o de ?leo e g?s, ? feita ininterruptamente e hoje ? capaz de ser realizada em regi?es de grande complexidade como nas chamadas ?guas profundas. Para isto, ? de extrema import?ncia a utiliza??o do fluido de perfura??o. Dentre os fluidos de perfura??o existentes, os fluidos de perfura??o ? base de ?leo s?o utilizados em situa??es nas quais se requer maior resist?ncia a temperaturas elevadas, baixa taxa de corros?o, baixa solubilidade das forma??es de sal, tais como as encontradas nas perfura??es da camada pr?-sal. Este trabalho teve como objetivo estudar reologicamente, atra? do STATISTICA 10, um fluido de perfura??o, produzido, a partir de um sistema microemulsionado, utilizando uma argila (bentonita) organofilizada. O fluido estudado foi constitu?do de n-parafina como fase ?leo, ?gua salina (35g/L de NaCl), tensoativo nonilfenoletoxilado com quatro graus de etoxila??o e a baritina, como adensante, para dar peso ao fluido e chegar ao peso de 8,5 lb/gal, usualmente utilizado em perfura??es e padr?o neste trabalho. O procedimento experimental foi dividido em seis etapas: processo de organofiliza??o da bentonita, na qual foi realizada a modifica??o superficial da argila atrav?s do tensoativo cati?nico brometo de hexadeciltrimetilam?nio (CTAB) em tr?s diferentes concentra??es: 30% acima da concentra??o micelar cr?tica (c.m.c); 30% abaixo da concentra??o micelar cr?tica (c.m.c); na concentra??o micelar cr?tica (c.m.c); an?lise da tens?o superficial e da molhabilidade, para assegurar que a modifica??o superficial foi realizada com sucesso; constru??o dos diagramas de fase tern?rios para obten??o dos sistemas microemulsionados; preparo do fluido de perfura??o; planejamento fatorial, para estudo estat?stico atrav?s do software STATISTICA 10.0; e an?lise reol?gica, que foi realizada no equipamento re?metro Thermo Cientific - HAAKE MARS (Modular Advanced Rheometer System) em tr?s diferentes temperaturas: 25?C, 45?C e 65?C. As vari?veis de respostas obtidas ap?s ensaio reol?gico foram: viscosidade pl?stica, viscosidade aparente, limite de escoamento e tixotropia. / For drilling of oil wells, one of the stages of oil and gas is of utmost importance to use the drilling fluid. Among the existing drilling fluids, the oil-based drilling fluids are used in situations which require higher strength at elevated temperatures, low corrosion rate, low solubility of the salt formations, such as those found in the perforations of the pre Layer-salt. This work aimed to study rheological, attracts STATISTICA 10 a drilling fluid, produced from a microemulsion system, using a clay (bentonite) organophilizated. The fluid was studied consisting of n-paraffin as oil phase, brine (35g / L NaCl), surfactant nonilfenoletoxilado with four degrees of ethoxylation and barytes as density modifier to give weight to the fluid and reach the weight 8.5 lb / gal, usually used in drilling and standard in this work. The experimental procedure was divided into six steps: organophilization process of bentonite, which was carried out the surface of the clay modified by the cationic surfactant hexadecyltrim ethylammonium bromide (CTAB) at three different concentrations: 30% above the critical micelle concentration (cmc); 30% below the critical micelle concentration (CMC); the critical micelle concentration (c.m.c); Analysis of surface tension and wettability, to assess the success of surface modification; Construction of ternary phase diagrams in order to obtain the microemulsion systems; preparation of drilling fluid; factorial design, to statistical study using STATISTICA software 10.0; and rheological analysis at three different temperatures: 25 ?C, 45 ?C and 65 ?C. The variable responses obtained after rheological testing were: plastic viscosity, apparent viscosity, yield stress and thixotropy. It was noticed increased wettability by decreasing the contact angle, as larger amounts of quaternary ammonium cations were adsorbed onto the clay surface. In addition, statistical analyzes have provided model equations to represent the response variables as a function of control variables significant for medium and predictive studied intervals.