Made available in DSpace on 2014-12-17T14:53:15Z (GMT). No. of bitstreams: 1 DiogoRMF_DISSERT.pdf: 1388214 bytes, checksum: 8814cfa4eedc7a31b0c8be932ce1962d (MD5) Previous issue date: 2012-07-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / O aumento do tr?fego urbano e a exig?ncia de maior efici?ncia das cadeias de suprimentos estimulam a busca por solu??es log?sticas capazes de possibilitar o atendimento dessas exig?ncias minimizando custos operacionais e reduzindo o tr?fego de ve?culos pesados para distribui??o nos grandes centros. A presente disserta??o visa a fornecer algoritmos de otimiza??o para o problema de localiza??o capacitado que consiste em selecionar os locais de instala??o de f?bricas e sat?lites de forma a minimizar os custos de um sistema multin?vel de transporte de carga. O algoritmo desenvolvido ser? validado por meio de experimentos realizados com inst?ncias geradas aleatoriamente, simulando cen?rios reais de distribui??o. Tais experimentos mostram a efici?ncia computacional dos m?todos heur?sticos desenvolvidos, sendo seu desempenho superior ao do solver CPLEX (ILOG) em redes de distribui??o com maior grau de complexidade

Made available in DSpace on 2014-12-17T15:01:35Z (GMT). No. of bitstreams: 1 ZanielSDP_DISSERT.pdf: 2717599 bytes, checksum: 57e9c7752ad1f265d12ad2b68b546c90 (MD5) Previous issue date: 2014-04-04 / Petr?leo Brasileiro SA - PETROBRAS / Microalgae are microscopic photosynthetic organisms that grow rapidly and in different environmental conditions due to their simple cellular structure. The cultivation of microalgae is a biological system capable of storing solar energy through the production of organic compounds via photosynthesis, and these species presents growth faster than land plants, enabling higher biomass yield. Thus, it is understood that the cultivation of these photosynthetic mechanisms is part of a relevant proposal, since, when compared to other oil producing raw materials, they have a significantly higher productivity, thus being a raw material able to complete the current demand by biodiesel . The overall aim of the thesis was to obtain biofuel via transesterification process of bio oil from the microalgae Isochrysis galbana. The specific objective was to estimate the use of a photobioreactor at the laboratory level, for the experiments of microalgae growth; evaluating the characteristics of biodiesel from microalgae produced by in situ transesterification process; studying a new route for disinfection of microalgae cultivation, through the use of the chemical agent sodium hypochlorite. The introduction of this new method allowed obtaining the kinetics of the photobioreactor for cultivation, besides getting the biomass needed for processing and analysis of experiments in obtaining biodiesel. The research showed acceptable results for the characteristics observed in the bio oil obtained, which fell within the standards of ANP Resolution No. 14, dated 11.5.2012 - 18.5.2012. Furthermore, it was demonstrated that the photobioreactor designed meet expectations about study culture growth and has contributed largely to the development of the chosen species of microalgae. Thus, it can be seen that the microalgae Isochrysis galbana showed a species with potential for biodiesel production / As microalgas s?o organismos microsc?picos fotossintetizantes que crescem rapidamente e em diferentes condi??es ambientais devido a sua simples estrutura celular. O cultivo de microalgas ? um sistema biol?gico capaz de armazenar energia solar, atrav?s da produ??o de compostos org?nicos via processo fotossint?tico, sendo que a maioria das esp?cies apresenta crescimento mais r?pido que as plantas terrestres, possibilitando maior rendimento de biomassa. Assim, compreende-se que o cultivo desses mecanismos fotossintetizantes se insere numa proposta relevante, uma vez que, quando comparados a outras mat?rias primas produtoras de ?leo, apresentam uma produtividade significativamente maior, sendo, portanto, uma mat?ria-prima capaz de completar a demanda atual de biodiesel. O objetivo geral da disserta??o foi a obten??o do biocombust?vel via processo de transesterifica??o do bio-?leo obtido a partir da microalga Isochrysis galbana. O estudo ainda teve por objetivos espec?ficos estimar o uso de um fotobiorreator em n?vel laboratorial, para realiza??o de experimentos de crescimento de microalgas; avaliar as caracter?sticas do biodiesel produzido por processo de transesterifica??o in situ da microalga; estudar uma nova rota para desinfec??o deste meio de cultura, por meio do uso do agente qu?mico hipoclorito de s?dio. Com a introdu??o deste novo m?todo foi poss?vel obter a cin?tica de crescimento do cultivo para o fotobiorreator, al?m de obter a biomassa necess?ria para transforma??o nos experimentos de an?lise e obten??o do biodiesel. A pesquisa apontou resultados aceit?veis para as caracter?sticas verificadas no bio-?leo obtido, o qual se enquadrou nos padr?es da resolu??o ANP N?14, de 11.5.2012 DOU 18.5.2012. Al?m disso, demonstrou-se que o fotobiorreator projetado atendeu ?s expectativas no que concerne ao crescimento do cultivo estudado e contribuiu amplamente para o desenvolvimento da esp?cie de microalga escolhida. Dessa maneira, pode-se constatar que a microalga Isochrysis galbana se mostrou uma esp?cie com potencial para a produ??o de biodiesel

Made available in DSpace on 2014-12-17T15:03:18Z (GMT). No. of bitstreams: 1 CarlosAlbertoBA.pdf: 931437 bytes, checksum: 7ce2bcd537fa9aeb002e3cff8e09ad45 (MD5) Previous issue date: 2007-04-04 / This work aims for the evaluation of Cruzeta Irrigated Perimeter, RN, which consists in the efficient use of water for agricultural production. The goal is looking for the available quantity of water for supplying required demands for adequate and economically viable cultures for the region. It is supposed that regional community water is supplied by pipelines from sources located outside of the region. From this study it is recommended the implantation of adequate installments for culture management in accordance with the availability of water resources and others conditionings. It must be considered the intensity of rainy and drought seasons in order to adjust the cultivated area and equipments to be operated, and also, the use of operating models and simulations in order to establish alert levels and eventually, reduction of irrigated area. Based on obtained data it is proposed the cultivation of different types of non-permanent cultures so that temporary cultures would be extensively produced in periods of abundant reservoir storage water permitting the transformation of storage water in storage culture products and few or no production in severe drought periods. This is the basic premise for sustainable agricultural development for Brazilian semiarid region / Este trabalho visa ? avalia??o do Per?metro Irrigado Cruzeta, RN, que consiste na utiliza??o eficiente da ?gua para a produ??o agr?cola, equacionando a quantidade dispon?vel de ?gua para atender a demanda requerida de um plantio adequado e economicamente vi?vel ? regi?o. Admite-se que a ?gua para abastecimento da popula??o seja provida por fonte ex?gena atrav?s de adutoras. Com base nesse estudo ser? recomendada a implanta??o de instala??es adequadas ao manejo de culturas a serem exploradas de acordo com a disponibilidade h?dricas e demais condicionantes, devendo-se levar em considera??o as esta??es secas e os anos de seca, onde as instala??es ficar?o parcialmente ou totalmente inativas; a constru??o de modelos de opera??o que se ajustem ?s esta??es chuvosas e secas e o estabelecimento de n?veis de alerta para a redu??o gradual da ?rea irrigada. Com base nos dados do estudo prop?e-se a produ??o de tipos de agricultura irrigada n?o permanentes, ou seja, culturas tempor?rias seriam extensivamente produzidas durante per?odos com grande armazenamento de ?gua, transformando ?gua represada em produtos estocados e pouca ou nenhuma produ??o durante os per?odos prolongados de seca. Essa ? a premissa b?sica de desenvolvimento agr?cola sustentado para o semi-?rido

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-12T14:44:41Z No. of bitstreams: 1 JessicaNayaraDeCarvalhoLeite_DISSERT.pdf: 1653844 bytes, checksum: a1fa3b230b445d2b44c344d47909c125 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-14T20:07:28Z (GMT) No. of bitstreams: 1 JessicaNayaraDeCarvalhoLeite_DISSERT.pdf: 1653844 bytes, checksum: a1fa3b230b445d2b44c344d47909c125 (MD5) / Made available in DSpace on 2018-03-14T20:07:28Z (GMT). No. of bitstreams: 1 JessicaNayaraDeCarvalhoLeite_DISSERT.pdf: 1653844 bytes, checksum: a1fa3b230b445d2b44c344d47909c125 (MD5) Previous issue date: 2017-11-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Em regi?es mais secas, muitos reservat?rios chegam a volumes t?o baixos que deixam de ser suficientes para abastecimento, sendo assim interrompida a tomada d??gua. No semi?rido brasileiro ? recorrente o esgotamento h?drico em alguns reservat?rios, os quais permanecem secos por meses ou at? anos, o que representa um problema para o abastecimento e causa preju?zos socioecon?micos. Ap?s um evento de esgotamento h?drico, em termos de impactos na qualidade da ?gua, espera-se que haja melhorias ap?s a renova??o com novas ?guas: Menor biomassa algal, maior transpar?ncia da ?gua, menor turbidez e baixa concentra??o de nutrientes. O objetivo deste estudo foi analisar a qualidade da ?gua de um reservat?rio do semi?rido tropical ap?s esgotamento h?drico durante um evento de seca prolongada. O reservat?rio estudado foi Dourado, localizado semi?rido brasileiro. O trabalho foi realizado com tr?s per?odos distintos, determinados de acordo com o volume h?drico. Os per?odos foram marcados por chuvas abaixo da m?dia hist?rica anual, estando assim inseridos em um per?odo de estiagem prolongada. Foram analisadas as vari?veis transpar?ncia da ?gua, turbidez, condutividade el?trica, pH, f?sforo total, f?sforo reativo dissolvido e clorofila-a. Ap?s a renova??o das ?guas, a expressiva redu??o na clorofila-a, indicativa de biomassa algal, indica melhora na qualidade da ?gua em termos de eutrofiza??o, devido ? mudan?a de estado de trofia de eutr?fico para mesotr?fico. As vari?veis pH, condutividade el?trica e turbidez tamb?m sofreram redu??o ap?s a renova??o das ?guas. N?o houve redu??o ap?s o aporte de ?gua para as vari?veis f?sforo total e f?sforo reativo dissolvido em compara??o aos per?odos anteriores. / In dry regions, many reservoirs reach volumes so low that they are no longer sufficient for supply, interrupting the water intake. In the Brazilian semi-arid region, occasional drying is recurrent in some reservoirs, which remains dry for months or even years, representing a problem for the supply and causing socioeconomic issues. After an event of drying, in terms of impacts on water quality, it is expected that there will be improvements after reflooding: Less algal biomass, increased water transparency, decreased turbidity and low concentration of nutrients. The aim of this study was to analyze the water quality of a tropical semi-arid reservoir after drying during an extended drought event. The studied reservoir was Dourado, located in the Brazilian semi-arid. This study consists of the comparison of three distinct periods accordingly to the water volume. Those periods were marked by rainfall below the annual historical average, therefore being inserted in an extended drought period. The variables water transparency, turbidity, electrical conductivity, pH, total phosphorus, soluble reactive phosphorus and chlorophyll-a were analyzed. After the water renewal, a significant reduction in chlorophyll-a, indicative of algal biomass, indicates an improvement in water quality in terms of eutrophication, due to the change of the trophic state from eutrophic to mesotrophic. pH, electrical conductivity and turbidity variables also reduced after the reflooding, indicating an improvement in water quality. There was no reduction in total phosphorus and soluble reactive phosphorus after the reflooding in comparison to the previous periods.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-12T20:16:45Z No. of bitstreams: 1 EwertonDaSilvaSantos_DISSERT.pdf: 1862280 bytes, checksum: f1f2785d323ba2a67e8e6e94f1350658 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-16T19:17:39Z (GMT) No. of bitstreams: 1 EwertonDaSilvaSantos_DISSERT.pdf: 1862280 bytes, checksum: f1f2785d323ba2a67e8e6e94f1350658 (MD5) / Made available in DSpace on 2018-03-16T19:17:39Z (GMT). No. of bitstreams: 1 EwertonDaSilvaSantos_DISSERT.pdf: 1862280 bytes, checksum: f1f2785d323ba2a67e8e6e94f1350658 (MD5) Previous issue date: 2018-02-02 / A popula??o brasileira vem passando por uma r?pida mudan?a em sua estrutura et?ria, como consequ?ncia de mudan?as em sua din?mica demogr?fica. Nesse contexto, observa-se uma redu??o na propor??o de crian?as e jovens, rapidez no processo de envelhecimento populacional e aumentos tanto na expectativa de vida ao nascer quanto na longevidade da popula??o. Com ganhos de sobreviv?ncia em quase todas as idades, em especial a partir dos 60 anos, analisar as condi??es de sa?de dessa popula??o sobrevivente sendo cada vez mais longeva ? importante para identificar a qualidade desse tempo de vida adicional. N?o obstante, sendo o Brasil um Pa?s de contrastes regionais, ? importante analisar os impactos do envelhecimento populacional e dos ganhos de longevidade diante dos diferentes contextos socioecon?micos e demogr?ficos nas Grandes Regi?es do Brasil. Este estudo estimou e analisou um indicador que incorpora, conjuntamente, mudan?as no n?vel de mortalidade e nas condi??es de sa?de da popula??o idosa, por caracter?sticas socioecon?micas e demogr?ficas entre as Grandes Regi?es do Brasil em 2013. As informa??es sobre mortalidade foram extra?das das t?buas oficiais de mortalidade de 2013 publicadas pelo IBGE. Enquanto que, a condi??o de sa?de da popula??o foi obtida com base nas informa??es sobre atividades da vida di?ria, coletadas na Pesquisa Nacional de Sa?de de 2013. Assim, analisaram-se os diferenciais regionais, socioecon?micos e demogr?ficos na Expectativa de Vida Livre de Incapacidade dos idosos residentes no Brasil em 2013. Como principais resultados observou-se que as mulheres viviam mais do que os homens, mas estavam em desvantagem em termos de EVLI. Para o Brasil, aos 60 anos, uma mulher teria uma sobrevida ativa de 19,4 anos e poderia esperar viver 4,0 anos com incapacidade funcional, os valores para a popula??o masculina seriam 17,3 e 2,6 anos, respectivamente. O subgrupo dos menos escolarizados, que vivem no Norte e Nordeste brasileiro, ? o que apresenta maior desvantagem em termos de EVLI, al?m de estarem abaixo da m?dia nacional. No entanto, diferen?as por ra?a e educa??o n?o foram estatisticamente significativas na maioria das Grandes Regi?es. Verificar os diferenciais na EVLI ? importante, pois os resultados podem servir como subs?dio para a avalia??o e planejamento das pol?ticas p?blicas voltadas aos cuidados com o idoso, definindo prioridades para h?bitos e estilos de vida saud?veis, minimizando demandas futuras na ?rea da sa?de, com uma maior aten??o para aqueles que se encontram em desvantagens. / The Brazilian population has been undergoing a rapid change in its structure as a consequence of changes in its demographic dynamics. In this context, there is a reduction in the proportion of children and young people, a rapid aging process and increases in both life expectancy at birth and longevity of the population. With survival gains in almost all ages, especially from the age of 60, analyzing how the health conditions of this survivor population being further and further away is important in identifying an additional lifetime duration. However, since Brazil is a country of regional contrasts, it is important to analyze the impacts of population aging and longevity gains in relation to the different socioeconomic and demographic contexts in the major Brazilian regions. This study estimated and analyzed the indication of jointly incorporating changes in the level of mortality and health conditions of the elderly population, by socioeconomic and demographic characteristics among the Great Regions of Brazil in 2013. As information on the mortality from those extracted from the official tables of mortality rates published by IBGE. While the population's health condition was obtained based on the information on activities of daily living collected in the National Health Survey of 2013. Thus, the regional, socioeconomic and demographic differentials in the Life Expectancy of Disability of the elderly people living in Brazil in 2013. The main results show that as women lived longer than men, they are at a disadvantage in terms of DFLE. For Brazil, at age 60, a woman with a lifespan of 19.4 years and since I expect to live 4.0 years with functional disability, the values for the male population would be 17.3 and 2.6 years respectively . The subgroup of the less educated, living in the North and Northeast of Brazil, is the one that presents the biggest disadvantage in terms of DFLE, besides being below the national average. However, there are no more details about race and education are not statistically significant in most regions. Checking the differentials in the EVLI is important, since the results can serve as a subsidy for the evaluation and planning of public policies aimed at the care of the elderly, setting priorities for healthy habits and lifestyles, minimizing future demands in the health area, with a attention to those who are disadvantaged.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-04-02T12:36:23Z No. of bitstreams: 1 IsaacDantasIsidorio_DISSERT.pdf: 4646525 bytes, checksum: bea5542be39899ce21aff1d1abc4b3cf (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-04T13:08:25Z (GMT) No. of bitstreams: 1 IsaacDantasIsidorio_DISSERT.pdf: 4646525 bytes, checksum: bea5542be39899ce21aff1d1abc4b3cf (MD5) / Made available in DSpace on 2018-04-04T13:08:25Z (GMT). No. of bitstreams: 1 IsaacDantasIsidorio_DISSERT.pdf: 4646525 bytes, checksum: bea5542be39899ce21aff1d1abc4b3cf (MD5) Previous issue date: 2018-01-31 / Dois m?todos principais se destacam no projeto de controladores adaptativos: o controle adaptativo por modelo de refer?ncia (MRAC) e o controle adaptativo por posicionamento de polos (APPC). No MRAC, um modelo de refer?ncia ? escolhido para gerar uma trajet?ria, a qual deve ser seguida pela sa?da da planta a ser controlada. Este tipo de projeto pode envolver o cancelamento dos zeros da planta, n?o sendo aplic?vel a plantas de fase n?o-m?nima. O APPC, por sua vez, ? considerado o tipo mais geral de controle adaptativo, apresentando uma metodologia de projeto para o controlador e lei de adapta??o bastante flex?veis, al?m de n?o envolver o cancelamento de zeros e polos da planta. A combina??o da estrutura do APPC e as leis chaveadas do VSC permite agregar rapidez no transit?rio e robustez a dist?rbios e varia??es param?tricas. Nesse contexto, baseado em uma classe de esquemas de controle por posicionamento de polos (PPC), surge o controle adaptativo por posicionamento de polos e estrutura vari?vel (VS-APPC). Aqui, assim como no APPC, a lei de controle ? gerada como no caso com par?metros (coeficientes da fun??o de transfer?ncia) conhecidos, substituindo estes por suas estimativas. O processo de estima??o identifica o m?todo adaptativo utilizado, de modo que o APPC utiliza leis integrais ao passo que o VS-APPC faz uso de leis chaveadas. Neste trabalho ? proposta a aplica??o do VS-APPC para o controle do sistema de Lorenz, utilizando apenas as medi??es das vari?veis de sa?da e entrada da planta no projeto. Os par?metros do sistema s?o considerados desconhecidos e ? considerada a presen?a de dist?rbio na entrada do sistema. ? observado que no sistema em malha fechada a vari?vel de sa?da segue a trajet?ria de refer?ncia e o vetor de estado converge para o estado de equil?brio, apresentando um bom comportamento transit?rio e robustez a incertezas param?tricas, como tamb?m, na presen?a de dist?rbios na entrada da planta. / Two main methods highlight for the design of adaptive controllers: the model reference adaptive control (MRAC) and the adaptive pole placement control (APPC). In MRAC, a reference model is chosen to generate a trajectory, which must be followed by the output of the plant to be controlled. This type of project may involve cancellation of the plant zeros, not applicable to non-minimum phase plants. APPC, in turn, is considered the most general type of adaptive control, presenting a design methodology for the controller and adaptation law quite flexible, besides not involving plant zero-pole cancellations. The combination of the APPC structure and the VSC switched laws allows aggregation of transient speed and robustness to disturbances and parametric variations. In this context, based on a class of pole placement control schemes (PPC), the variable structure adaptive pole placement control (VS-APPC) arises. Here, such as in APPC, the control law is generated as in the case with known parameters (transfer function coefficients), replacing them by their estimates. The estimation process identifies the adaptive method used, so that APPC uses integral laws while the VS-APPC makes use of switching laws. In this work is proposed the application of VS-APPC for the control of the Lorenz system, using only the measured plant output and input variables in design. The parameters of system are considered unknown and is considered the disturbance presence in system input. It is observed that in closed-loop system, the output tracks the reference trajectory and the state vector converges to the equilibrium state, presenting good transient behavior and robustness to the parametrics uncertainties as also in presence of disturbance in plant input.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-02T12:02:51Z No. of bitstreams: 1 FranklinKaicDutraPereira_DISSERT.pdf: 4927080 bytes, checksum: 2819590cb07d91690515be5ccc3a0f65 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-06T21:43:53Z (GMT) No. of bitstreams: 1 FranklinKaicDutraPereira_DISSERT.pdf: 4927080 bytes, checksum: 2819590cb07d91690515be5ccc3a0f65 (MD5) / Made available in DSpace on 2017-02-06T21:43:53Z (GMT). No. of bitstreams: 1 FranklinKaicDutraPereira_DISSERT.pdf: 4927080 bytes, checksum: 2819590cb07d91690515be5ccc3a0f65 (MD5) Previous issue date: 2016-07-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O biodiesel e o diesel s?o subst?ncias org?nicas e corrosivas, que podem atacar tanques de combust?veis met?licos, hastes de conex?o, sistemas de tubula??es, a?o de transporte e armazenamento, dentre outros constituintes met?licos. Atualmente, metais e a?os, a exemplo do a?o AISI 316, est?o sendo cada vez mais usados em tanques de transporte e armazenamento de biocombust?veis. Com tais pressupostos, o objetivo do trabalho foi avaliar e comparar a a??o corrosiva de diferentes biodieseis sobre o a?o AISI 316. A metodologia consistiu na an?lise fisico-qu?mica dos ?leos de soja, girassol e mamona, posteriormente os biodeiseis foram sintetizados atrav?s da rea??o de transesterifica??o pelas rotas met?lica e et?lica, fazendo uso do KOH como catalisador. Os biocombust?veis foram caracterizados seguindo as normas American Society of Testing Materials (ASTM) e por Espectroscopia de Infravermelho por Transformada de Fourier (FTIR). Avaliou-se tamb?m o B7 dispon?vel comercialmente. As estabilidades t?rmicas foram avaliadas via Termogravimetria (TG, DTG e DTA) e Calorimetria Explorat?ria Diferencial Din?mica (DSC). O ensaio de corros?o consistiu em teste de imers?o do a?o em estudo, em diferentes horas. Foram utilizadas as medidas de Polariza??o Potenciodin?mica Linear (PPL) e Espectroscopia de Imped?ncia Eletroqu?mica (EIE), para a avalia??o eletroqu?mica de corros?o. Posteriormente, o a?o foi analisado atrav?s de Microscopia Eletr?nica de Varredura (MEV), acoplado ao Espectr?metro de Energia Dispersiva de Raios X (EDS), e foi realizado an?lise qu?mica via Fluoresc?ncia de Raio X (FRX). Os resultados comprovaram que os biodieseis est?o conforme as normas espec?ficas da Ag?ncia Nacional do Petr?leo, G?s Natural e Biocombust?veis (ANP). Os conjuntos das t?cnicas indicaram que houve perda de massa e a an?lise da superf?cie evidenciou corros?o localizada por pitting. Com as curvas de polariza??o e imped?ncia eletroqu?mica, observou-se que todos os biocombust?veis s?o agentes corrosivos, portanto, redutores. O B7 ? o flu?do que mais corr?i os corpos de prova, fazendo uma nuclea??o de ?xido, formando a passiva??o met?lica ap?s serem atacados pelo biocombust?vel. Por meio do FRX, observou-se que os biocombust?veis foram contaminados por metais de transi??o, quando expostos ao a?o, catalisando rea??es de degrada??o dos biocombust?veis formando hidroper?xidos, o que se confirmou pelas mudan?as nas vibra??es dos espectros do FTIR. O tratamento estat?stico comprovou que o modelo ? aceit?vel e confi?vel, pois a an?lise de ru?dos est? pr?xima ? linha padr?o. O Modelo de Superf?cie de Resposta (MSR) indicou que o tempo de imers?o ? o fator que mais influencia na taxa de corros?o nos biodieseis sintetizados pela rota met?lica, enquanto o ?ndice de acidez ? o que mais influencia nos ?steres et?licos. / Biodiesel and diesel are organic and corrosive substances that can attack metal fuel tanks, connecting rods, piping systems, transportation and storage of steel, among other metallic constituents. Currently, metal and steel, such as the AISI 316 steel, are being increasingly used in tanks for transport and storage of biofuels. With such assumptions, the study aimed to evaluate and compare the corrosive action of different biodiesels on steel AISI 316. The methodology consisted of physic-chemical analysis of soybean oil, sunflower oil and castor oil. The biodiesels were synthesized by the transesterification reaction by the methyl and ethyl routes, making use of NaOH as catalyst. Biofuels were characterized following the guidelines of the American Society of Testing Materials (ASTM), Fourier Transform Infrared Spectrometry (FTIR). Also it evaluated B7 commercially available. The thermal stabilities were evaluated by Termogravimetric Analysis (TG, DTG and DTA) and Differential Scanning Calorimetry Dynamics (DSC). The corrosion test consisted of immersing the steel under biofuel sat different times. It were used Linear Potentiodynamic Polarization (PPL) measurements and Electrochemical Impedance Spectroscopy (EIS) for the electrochemical evaluation of corrosion. Subsequently, the steel was analyzed by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-Ray Spectrometer (EDS), and was carried out chemical analysis via X-Ray Fluorescence (XRF). Findings showed that biodiesels were like stated by National Agency of Petroleum (NAP) standards. The sets of the techniques indicated a weight loss, and surface analysis evidenced general pitting corrosion. With the polarization curves and electrochemical impedance spectroscopy, it was observed that all biofuels are corrosive agents, therefore, reducers. The B7 is the fluid that corrodes more the samples, which by having a nucleation of oxide form the metal passivation after being attacked by biofuels. By XRF, it was observed that biofuels have been contaminated with transition metals when exposed to the steel, causing the formation of free radicals that induce autoxidation, forming hydroperoxides, which was confirmed by changes in vibrations of FTIR spectra. Statistical analysis indicated that the model is acceptable and reliable, because the noise analysis is close to the standard range. The Response Surface Methodology (RSM) indicated that the immersion time is the factor that most influences the corrosion rate in biodiesels synthesized by methyl route, while the acid value is what most influences in ethyl esters.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-14T22:33:05Z No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-16T19:54:31Z (GMT) No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) / Made available in DSpace on 2017-03-16T19:54:31Z (GMT). No. of bitstreams: 1 ThiagoVieiraFonseca_DISSERT.pdf: 2958142 bytes, checksum: c66f334f99f3044869ebf39752984389 (MD5) Previous issue date: 2016-12-15 / O concreto autoadens?vel (CAA) possui elevado teor de materiais finos e vem sendo bastante utilizado devido as suas caracter?sticas de alta fluidez e coes?o. Os finos provindos de res?duos ou subprodutos industriais podem vir a ser usados em prol da sustentabilidade, minimizando consideravelmente o consumo de cimento associado ? possibilidade de manter, ou melhorar, as propriedades mec?nicas ou de durabilidade. Desta forma, o presente trabalho investigou a viabilidade do desenvolvimento de CAA?s confeccionados com elevados teores de adi??es minerais e cal hidratada. Para isso, o cimento foi substitu?do por adi??es minerais (pozolana da casca do arroz, metacaulim e f?ler calc?rio) no teor de 60%, com base no tra?o de refer?ncia com consumo de 451,1 kg/m? de cimento, originando novos tra?os com consumos de cimento entre 167,7 kg/m? e 173,3 kg/m?. A cal hidratada foi incorporada como adi??o em tr?s tra?os no teor de 5% sobre a massa total dos materiais finos. Os CAA?s foram caracterizados no estado fresco pelos ensaios de espalhamento, T500, anel-J, funil-V e caixa-L. Para avalia??o do desempenho mec?nico dos CAA?s foram realizados ensaios de resist?ncia ? compress?o, velocidade do pulso ultrass?nico e m?dulo de elasticidade est?tico, bem como propriedades de transporte relacionadas ? durabilidade: absor??o por capilaridade, difus?o de ?ons cloreto, resistividade el?trica e carbonata??o. Os CAA?s com adi??es minerais apresentaram desempenho mec?nico satisfat?rio, embora inferiores ao do tra?o de refer?ncia. As resist?ncias ? compress?o aos 28 dias dos concretos com adi??es minerais apresentaram redu??o de 15 a 60% em rela??o ao tra?o de refer?ncia, mas todos os resultados foram compat?veis com concretos estruturais de acordo com os requisitos da NBR 6118 (ABNT, 2014). Com rela??o a durabilidade, os concretos com adi??es minerais apresentaram redu??o do coeficiente de difus?o de ?ons cloreto que variaram entre 25,4% e 74,8%. As resistividades el?tricas do concreto de refer?ncia foram bastante inferiores ?s dos concretos com adi??es minerais, mas todas as composi??es estudadas foram classificadas como prov?vel taxa de corros?o desprez?vel. As resistividades el?tricas sofreram grande redu??o quando analisadas em amostras carbonatadas. J? a an?lise da carbonata??o acelerada mostrou que a substitui??o do cimento por adi??es minerais em elevados teores torna os CAA?s bastante suscet?veis a carbonata??o. Quanto a adi??o de cal hidratada, n?o foi verificada influ?ncia positiva no desempenho mec?nico dos CAA?s estudados, mas observou-se que sua utiliza??o proporcionou redu??o da profundidade de carbonata??o nos CAA?s devido a reposi??o da reserva alcalina. / Self-compacting concrete (SCC) has a high content of fine materials and has been widely used due to its characteristics of high fluidity and cohesion. Fines from industrial waste or by-products may be used for the sake of sustainability, considerably reducing the consumption of cement associated with the possibility of maintaining or improving mechanical or durability properties. In this way, the present work investigated the feasibility of the development of SCC's made with high levels of mineral additions and hydrated lime. For this purpose, the cement was replaced by mineral additives (rice husk pozzolan, metakaolin and limestone filer) in the 60% content, based on the reference mixture with consumption of 451.1 kg / m? of cement, giving rise to new mixtures with consumption of cement between 167.7 kg / m? and 173.3 kg / m?. The hydrated lime was incorporated as an addition in three mixtures in the content of 5% on the total mass of the fine materials. The SCC's were characterized in the fresh state by the slump flow test, T500, J-ring, V-funnel and L-box. To evaluate the mechanical performance of the SCC's, tests of compressive strength, ultrasonic pulse velocity and static modulus of elasticity, as well as transport properties related to durability were performed: capillary absorption, chloride ion diffusion, electrical resistivity and carbonation. The SCC's with mineral additions presented satisfactory mechanical performance, although lower than the reference mixture. The compressive strength at 28 days of the concretes with mineral additions showed a reduction of 15 to 60% in relation to the reference mixture, but all the results were compatible with structural concretes according to the requirements of NBR 6118 (ABNT, 2014). Regarding the durability, the concrete with mineral additions presented reduction of the diffusion coefficient of chloride ions that varied between 25.4% and 74.8%. The electrical resistivities of the reference concrete were much lower than those of the concretes with mineral additions, but all the studied compositions were classified as probable negligible corrosion rates. The electrical resistivities suffered great reduction when analyzed in carbonated samples. The analysis of the accelerated carbonation showed that the substitution of cement by mineral additions at high levels makes the SCC very susceptible to carbonation. As for the addition of hydrated lime, there was no positive influence on the mechanical performance of the SCC's studied, but it was observed that its use provided a reduction of the carbonation depth in the SCC's due to the alkaline reserve.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T21:03:01Z No. of bitstreams: 1 PedroDaniloGaldinoVitorPereira_DISSERT.pdf: 1001427 bytes, checksum: 369e9208b5b3b076acb2435df546cb28 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-23T18:24:43Z (GMT) No. of bitstreams: 1 PedroDaniloGaldinoVitorPereira_DISSERT.pdf: 1001427 bytes, checksum: 369e9208b5b3b076acb2435df546cb28 (MD5) / Made available in DSpace on 2017-03-23T18:24:44Z (GMT). No. of bitstreams: 1 PedroDaniloGaldinoVitorPereira_DISSERT.pdf: 1001427 bytes, checksum: 369e9208b5b3b076acb2435df546cb28 (MD5) Previous issue date: 2016-12-05 / O presente trabalho discutir? a rela??o entre est?tica e pol?tica na obra do fil?sofo franc?s Jacques Ranci?re, a partir, principalmente, do conceito de partilha do sens?vel. Para Ranci?re h? um campo comum que une essas duas esferas do saber humano, a est?tica primeira que se refere a um a priori da sensibilidade. Neste sentido, tanto a arte quanto a pol?tica podem intervir neste tecido da sensibilidade, reconfigurando a partilha do sens?vel de maneira dissensual. H?, segundo o autor, uma dicotomia no campo da partilha do sens?vel, duas l?gicas que organizam ou redistribuem as ativi-dades, os tempos e espa?os. De um lado, uma l?gica do consenso e da boa ordena-??o das posi??es e, de outro lado, uma l?gica que funciona nas fronteiras da domina-??o, criando um sens?vel conflituoso. A partir deste campo comum da partilha do sen-s?vel, Ranci?re colocar? em discuss?o como as artes afetam o tecido das partilhas e como ganha um car?ter pol?tico por esta raz?o. O objetivo desta disserta??o ? apre-sentar e discutir como ? poss?vel a emancipa??o se efetivar a partir da pr?tica de indiv?duos como prolet?rios ou artistas, pensando as rela??es entre est?tica e pol?tica. / This work will discuss the relationship between aesthetics and politics in the work of the French philosopher Jacques Ranci?re, based mainly on the concept of distribution of the sensible. For Ranci?re there is a common field that joins these two spheres of human knowledge, the primary aesthetics referred to an a priori of sensitivity. In this sense, both art and politics can intervene in this sensory fabric, reconfiguring the dis-tribution of the sensible dissensual way. There is, according to the author, a dichotomy in the field of distribution of the sensible, two logics that organize or redistribute the activities, times and spaces. On the one hand, a logic of consensus and good order of locations and on an other hand, a logic that works on the frontiers of domination, cre-ating a disruptive sensible. From this common ground of distribution of the sensible, Ranci?re put in discussion how the arts affect the fabric of the distribution and how to get a political character for this reason. The aim of this work is to present and discuss how it is possible to effective the emancipation from the practice of subjects as workers or artists, thinking the relationship between aesthetics and politics.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T23:06:42Z No. of bitstreams: 1 WesleyFeuDosSantos_DISSERT.pdf: 2488767 bytes, checksum: 54fa9201753bfbbe0b0ff0a295b2a4ac (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-24T21:53:11Z (GMT) No. of bitstreams: 1 WesleyFeuDosSantos_DISSERT.pdf: 2488767 bytes, checksum: 54fa9201753bfbbe0b0ff0a295b2a4ac (MD5) / Made available in DSpace on 2017-03-24T21:53:11Z (GMT). No. of bitstreams: 1 WesleyFeuDosSantos_DISSERT.pdf: 2488767 bytes, checksum: 54fa9201753bfbbe0b0ff0a295b2a4ac (MD5) Previous issue date: 2016-09-09 / A fabrica??o do Cimento Portland ? uma atividade que causa grande impacto ambiental devido ? sua elevada taxa de emiss?o de CO2 na atmosfera. Visando reduzir esse impacto, a viabilidade t?cnica de materiais alternativos em substitui??o ao Cimento Portland tem sido cada vez mais analisada. J? s?o conhecidos os benef?cios que as adi??es minerais infere ao concreto convencional (CV), no entanto, existe a necessidade de compreender melhor seus benef?cios quando utilizadas em CAA e verificar o comportamento deste quando curado termicamente. Assim, este trabalho avalia os efeitos da incorpora??o de f?ler calc?rio (Fc) e metacaulim (Mk) na hidrata??o do concreto autoadens?vel, quando submetido ? cura t?rmica. Para tanto, foram produzidos seis composi??es de CAA, sendo uma de refer?ncia, sem adi??o mineral, quatro misturas bin?rias com substitui??o do cimento por 10% de Mk, 10% Fc, 20% de Mk e 20% Fc e uma terci?ria com substitui??o do cimento por 10% de Mk e 10% de Fc. Os concretos foram dosados e realizados os ensaios realizados para os concretos dosados foram: slump flow, T500, L-box, V-test e J-ring para caracteriza??o do CAA no estado fresco. Ap?s iniciada a pega (aproximadamente 3 horas), intervalo chamado de pr?-cura, os corpos de prova moldados foram curados atrav?s de imers?o total em banho aquecido. A taxa de aquecimento utilizada foi de 20 ?C/h, chegando ?s temperaturas m?ximas de 50, 60 e 70 ?C, com posterior resfriamento de 10 ?C/h. O tempo total do ciclo (pr?-cura, aquecimento, patamar isot?rmico e resfriamento), foi de 18 a 20 horas. Tamb?m foram confeccionados corpos de prova de CAA que foram curados por imers?o em ?gua a temperatura ambiente. As propriedades analisadas no estado endurecido de todas as composi??es foram: resist?ncia ? compress?o nas idades de 1, 3, 7 e 28 dias, com m?dulo de elasticidade din?mico, absor??o de ?gua por capilaridade, massa espec?fica e absor??o total aos 28 dias de idade. A an?lise da microestrutura dos diferentes concretos se deu por microscopia eletr?nica de varredura e difra??o de raios X aos 3 e 28 dias de idade. As adi??es de metacaulim e filer calc?rio podem substituir o cimento Portland, nos percentuais de 10% e 20%, de maneira satisfat?ria em misturas bin?rias e terci?rias. Aos 28 dias de idade, os CAA curados termicamente em geral n?o apresentaram resist?ncias ? compress?o inferiores aos curados a 28 ?C. A cura t?rmica ?mida por imers?o propicia um aumento na resist?ncia ? compress?o nas primeiras idades, exceto para os concretos contendo 20% de f?ler calc?rio em substitui??o ao cimento Portland. Para cada tra?o estudado, houve um temperatura que se mostrou mais eficaz, ou seja, uma temperatura patamar mais adequada. Na an?lise da microestrutura dos CAA pode se observar que a elevada resist?ncia obtida a 1 dia de idade, deve-se a r?pida forma??o de CSH para os CAA tratados termicamente. / The manufacture of Portland cement is an activity that causes great environmental impact due to its high CO2 emission rate in the atmosphere. In order to reduce this impact, technical feasibility of alternative materials to replace Portland cement has been increasingly analyzed. It is already known the benefits that mineral additions infers to conventional concrete (CV), however, little is known of their use in self-compacting concrete (SCC) subjected to heat treatment. This work evaluates the effects of the incorporation of limestone fillers (LP) and metakaolin (MK) in the hydration of self-compacting concrete, when subjected to thermal curing. For this purpose six SCC compositions were produced, as a reference without mineral addition, four binary mixtures with replacement of cement with 10% MK, 10% LP, 20% MK and 20% LP and a tertiary with substitution of cement by 10% MK and 10% LP. The concrete were measured and made the tests slump flow, T500, L-box, V-test and J-ring to characterize the SCC fresh. After started the crystallization reactions (about 3 hours), range called pre-curing, the molded specimens were cured through total immersion in a warm bath. The heating rate used was 20 ?C/hr, reaching the maximum temperatures 50, 60 and 70 ?C, with subsequent cooling 10 ?C/hr. The total cycle time (pre-curing, heating, cooling and isothermal level) was 18 to 20 hours. Also, specimens were prepared which were cured by immersion in water at room temperature. The analyzed properties in the hardened state of all compositions were compressive strength at ages of 1, 3, 7 and 28 days at modulus, water absorption by capillarity, density, and total absorption to 28 days of age. The analysis of the microstructure of different concrete was given by scanning electron microscopy and X-ray diffraction at 1 and 28 days of age. The CAA thermally cured obtained a high increase in compressive strength at 1 day old, when compared to CAA cured at room temperature. For each dosage analyzed, there is a maximum temperature within the thermal cycle, which provides better mechanical performance to the CAA. The thermal curing causes changes in the microstructure, including, promote the rapid formation of calcium silicate hydrate (CSH). The additions of metakaolin and lime filer can replace Portland cement in percentages of 10% and 20%, satisfactorily in binary and tertiary mixtures. After 28 days the CAA cured thermally groups showed no resistance to compression to lower cured at 28 ? C. The wet thermal curing dip provides an increase in compressive strength at early ages, except for the concrete containing 20% filler limestone to replace Portland cement. For each studied trait, there was a temperature that was more effective, i.e., a temperature most suitable level. The analysis of the microstructure of the CAA can be seen that the high strength obtained at 1 day old, due to rapid formation of the CSH to the heat-treated CAA.