Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-01T21:32:18Z No. of bitstreams: 1 NatanaeyfleRandembergGomesDosSantos_TESE.pdf: 3542697 bytes, checksum: 97843b739f0b1a5bdcb53b7f88ac2d7a (MD5) / Approved for entry into archive by Elisangela Moura (lilaalves@gmail.com) on 2016-02-16T20:41:39Z (GMT) No. of bitstreams: 1 NatanaeyfleRandembergGomesDosSantos_TESE.pdf: 3542697 bytes, checksum: 97843b739f0b1a5bdcb53b7f88ac2d7a (MD5) / Made available in DSpace on 2016-02-16T20:41:39Z (GMT). No. of bitstreams: 1 NatanaeyfleRandembergGomesDosSantos_TESE.pdf: 3542697 bytes, checksum: 97843b739f0b1a5bdcb53b7f88ac2d7a (MD5) Previous issue date: 2015-02-05 / A utiliza??o de materiais comp?sitos para a constru??o civil tem sido tema de in?meros trabalhos cient?ficos no Brasil e no mundo. Um dos fatores que motivam essa busca ? o d?ficit habitacional que os pa?ses principalmente do terceiro mundo enfrentam. No Brasil esse d?ficit alcan?a mais de 6,5 milh?es de moradias, em torno de 12% dos domic?lios do pa?s. Esse trabalho apresenta um comp?sito que foi obtido a partir de res?duos gerados nos processos de obten??o de placas de granito e m?rmore, cimento, gesso, areia, EPS triturado e ?gua. Esses res?duos causam grandes danos ao meio ambiente e s?o jogados em aterros em grandes quantidades. O ineditismo do trabalho est? no estudo combinado t?rmico, mec?nico e ac?stica do comp?sito obtido, em situa??o real, de c?modos que fazem parte de uma habita??o experimental. Foram confeccionados diversos blocos a partir de composi??es variadas e foram efetuados testes preliminares de resist?ncia mec?nica e t?rmica, escolhendo-se a propor??o mais apropriada. Ser?o apresentados os processos de fabrica??o e montagem dos blocos produzidos, em n?mero de 500, para a fabrica??o de uma resid?ncia experimental. Estudou-se qual o tipo de bloco e de res?duo, m?rmore ou granito, apresentou-se mais vi?vel para o fim proposto. A resist?ncia mec?nica dos blocos produzidos esteve acima de 3,0 MPa. A resist?ncia t?rmica dos blocos foi comprovada pela diferen?a m?xima entre as paredes interna e externa dos c?modos edificados em torno 8,0 ?C. A absor??o ac?stica para o c?modo mais eficiente ficou em torno 31. Demonstrou-se a viabilidade de utiliza??o dos blocos fabricados com o material comp?sito proposto para a constru??o civil. / The use of composite materials for the construction industry has been the subject of numerous scientific papers in Brazil and in the world. One of the factors that motivate this quest is the housing deficit that countries especially the third world face. In Brazil this deficit reaches more than 6.5 million homes, around 12% of all US households . This paper presents a composite that was obtained from waste generated in processes for the production of granite and marble slabs, cement, gypsum, sand, crushed EPS and water. These wastes cause great damage to the environment and are thrown into landfi lls in bulk. The novelty of the work is in the combined study thermal, mechanical and acoustic composite obtained in real situation of rooms that are part of an experimental housing. Many blocks were made from cement compositions, plaster, foam, sand, marb le and / or granite, preliminary tests of mechanical and thermal resistance were made by choosing the most appropriate proportion. Will be given the manufacturing processes and assembly units 500 units 10 x 80 x 28 cm produced for the construction of an ex perimental home. We studied what kind of block and residue, marble or granite, made it more feasible for the intended purpose. The mechanical strength of the produced blocks were above 3.0 MPa. The thermal resistance of the blocks was confirmed by the maxi mum temperature difference between the inner and outer walls of rooms built around 8.0 ? C. The sound absorption for optimal room was around 31%. Demonstrated the feasibility of using the blocks manufactured with composite material proposed for construction.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T21:07:59Z No. of bitstreams: 1 JoseRenatoLimaCamara_DISSERT.pdf: 3552276 bytes, checksum: b25cc5d6b64a03d05ff895c1737a2060 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-12T23:11:02Z (GMT) No. of bitstreams: 1 JoseRenatoLimaCamara_DISSERT.pdf: 3552276 bytes, checksum: b25cc5d6b64a03d05ff895c1737a2060 (MD5) / Made available in DSpace on 2016-05-12T23:11:02Z (GMT). No. of bitstreams: 1 JoseRenatoLimaCamara_DISSERT.pdf: 3552276 bytes, checksum: b25cc5d6b64a03d05ff895c1737a2060 (MD5) Previous issue date: 2015-07-31 / Este trabalho consiste no desenvolvimento de um comp?sito a base de rejeito de telha epoliuretano de mamona, tendo como objetivo utilizar como isolantes t?rmicos para o mercadoconsumidor. Na etapa experimental o rejeito de telha foi mo?do e peneirado ? 200 mesh ecaracterizados por fluoresc?ncia de raios-X (FRX), difra??o de raios-X ( DRX), Microscopiaeletr?nica de varredura (MeV) e granulometria a laser, para analisar os elementos constituintes,fases presentes, defeitos e tamanho do gr?o. Para a fabrica??o da espuma r?gida do poliuretano demamona puro, foram utilizados dois componentes polim?ricos A e B nas propor??es de 1:1,6.Foram desenvolvidas cinco formula??es: FI, FII, FIII, FIV, FV e FVI (0%, 10%, 20%, 30%, 40%,e 50 % de rejeito de telha, respectivamente) para fabrica??o do comp?sito. As propriedadesmec?nicas foram determinadas atrav?s de ensaios de compress?o e ensaio Shore A. J? aspropriedades t?rmicas foram determinadas a partir de ensaios de condutividade t?rmica, calorespec?fico, difusividade t?rmica, absor??o de ?gua e massa especifica. Os resultados morfol?gicosdo comp?sito apresentaram aglomerados de poros fechados, o que p?de ter contribu?do para aredu??o da resist?ncia e da massa espec?fica mec?nica, principalmente da formula??o FVI. Assim,foi percebido que o aumento do teor de rejeito de telha na matriz do poliuretano n?o modificou aspropriedades termofisicas do material. Contudo, o rejeito de telha contribuiu para diminui??o daquantidade de poliuretano usado na fabrica??o de componentes t?rmicos. Os valores apresentadospelos comp?sitos (rejeito de telha + poliuretano) foram similares na formula??o FIII, FIV e FV.Pois os mesmo n?o variaram muito em rela??o ao poliuretano puro. Com isso o material fabricadopode ser aplicado como isolantes t?rmicos, al?m disto, o seu uso pode contribuir na quest?oambiental, por ser um material biodegrad?vel devido ? utiliza??o do rejeito de telha como mat?riaprima e reduzindo custos de fabrica??o. / Studied a composite reject the base tile and castor oil polyurethane, aiming their use as insulation for the consumer market. In the experimental stage the reject tile was ground and sieved at 200 mesh and characterized by fluorescence X-ray (XRF), diffraction X-ray (XRD), scanning electron microscopy (SEM) and laser granulometry, to analyze the constituent elements, phases present, defects and grain size. For the manufacture of rigid foam polyurethane pure castor two polymer components A and B were used (40- Respan) in the proportions of 1 part to component A and 1.6 parts of component B. six formulations were developed: FI, FII, FIII, FIV, FV and FVI (0%, 10%, 20%, 30%, 40% and 50% reject tile, respectively) for the manufacture of the composite. The mechanical properties were determined by compression testing and hardness testing Shore A. Thermal properties were determined from test thermal conductivity, specific heat, thermal diffusivity. The technological tests were water absorption, bulk density and porosity of the composite Morphological results showed clusters of closed pores, which may have contributed to the reduction of the mechanical strength and density, especially of IVF formulation. It was noted that increasing the tile waste content in the polyurethane matrix did not change the thermo-physical properties of the material. However, the waste tile contributed to decreasing the amount of polyurethane used in the manufacture of thermal components. The values presented the composite properties (tailings tile + polyurethane) were similar in formulations FIII, FIV and FV. The obtained composite can be applied as an insulator and may contribute to the environmental issues because it is a biodegradable material due to the use of tile as raw material waste and reducing manufacturing costs.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-10T21:07:59Z No. of bitstreams: 1 LucianoLeonardoLopesCosta_DISSERT.pdf: 2685807 bytes, checksum: cd44bd3b6242d63070197e5e8c9d88a2 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-12T23:35:09Z (GMT) No. of bitstreams: 1 LucianoLeonardoLopesCosta_DISSERT.pdf: 2685807 bytes, checksum: cd44bd3b6242d63070197e5e8c9d88a2 (MD5) / Made available in DSpace on 2016-05-12T23:35:09Z (GMT). No. of bitstreams: 1 LucianoLeonardoLopesCosta_DISSERT.pdf: 2685807 bytes, checksum: cd44bd3b6242d63070197e5e8c9d88a2 (MD5) Previous issue date: 2015-08-12 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Tendo em vista a crescente busca por materiais que possam cada vez mais melhorar a efici?ncia de isolantes t?rmicos e que n?o causem agress?o ao meio ambiente, temos a utiliza??o da palha da carna?ba como uma alternativa de refor?o em comp?sitos de isola??o t?rmica. O comp?sito ? formado por fibras naturais da folha da carna?ba que possui propriedades f?sico-qu?micas desej?veis para ser utilizado como isolante t?rmico e o min?rio Caulim, que se caracteriza por ser quimicamente inerte e possuir baixa condutividade t?rmica. O comp?sito citado foi submetido a ensaios para determinar a sua condutividade t?rmica, densidade e resist?ncia ? temperatura. As propriedades f?sicas, estruturais e morfol?gicas das mat?rias-primas foram investigadas atrav?s de an?lises de termogravimetria, difra??o de raios X, fluoresc?ncia de raios X e microscopia eletr?nica de varredura. / Thinking about the growing search for materials than can improve the efficiency of thermal insulations, and that do not cause aggressions to the environment, we decided to use the leaf of the carnauba as an alternative reinforcement in composites of thermal insulation. The composite is formed by natural fibers of leaves of the carnauba, that possesses good physicochemical properties to work as a thermal insulation and the minerium caulim, that is characterized for being chemical inert and possesses low thermal conductivity. The carna?ba straw acquired was-covered with impurities, it was subjected to various washing processes for these impurities do not interfere in the tests, the caulimwas used without any treatment for their processing. After cleaning, the straw was milled in a knife mill to be in the form of powder, this powder was mixed with kaolin to be more homogeneous, the mixture was properly hydrated and pressed to make specimenfor testing.The composite was divided into formulations of 10%, 30% and 50%, this value indicates the percentage of the fiber mass of the carnauba powderper total mass of the composite, after that, the specimens were manufactured by the pressing method. The specimens have been tested to determine conductivity, resistance, diffusivity. Analyses of thermogravimetry, x-ray diffraction, x-ray fluorescence were done, and a compression test to determine whether it could be used in wall cladding. The composite showed satisfactory results in their thermal characteristics, the composite showed satisfactory results in their thermal characteristics , with an operating range of up to 150 ? C and an average thermal conductivity of 0.199 W /m.K and quite feasible in the item cost-effective, but somewhat limited by their place of application.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:57:10Z No. of bitstreams: 1 ItailzaGomesDaRocha_DISSERT.pdf: 3542376 bytes, checksum: feceaf0a2a5196b154b6fcc7af590782 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T21:10:55Z (GMT) No. of bitstreams: 1 ItailzaGomesDaRocha_DISSERT.pdf: 3542376 bytes, checksum: feceaf0a2a5196b154b6fcc7af590782 (MD5) / Made available in DSpace on 2016-06-07T21:10:55Z (GMT). No. of bitstreams: 1 ItailzaGomesDaRocha_DISSERT.pdf: 3542376 bytes, checksum: feceaf0a2a5196b154b6fcc7af590782 (MD5) Previous issue date: 2015-09-08 / Atualmente se observa uma grande busca por materiais originados de fontes renov?veis. As fibras vegetais como refor?o para matrizes polim?ricas, tem sido uma alternativa para substituir fibras sint?ticas, por serem biodegrad?veis e de baixo custo. Este trabalho objetiva desenvolver um material comp?sito de resina ep?xi refor?ado com fibra de curau? e aditivo retardante de chama de alumina trihidratada (hidr?xido de alum?nio - Al(OH)3), que foi utilizado em propor??es de 10%, 20% e 30% do volume total do comp?sito. As fibras de curau? passaram por um processo de limpeza com um banho alcalino de hidr?xido de s?dio (NaOH), paralelizadas atrav?s de cardagem manual e cortadas de acordo com o comprimento predefinido. Foram moldados comp?sitos com fibras de 30cm e com fra??o volum?trica de 20% de fibra no Lossy Mould. Os comp?sitos foram preparados no Laborat?rio de Engenharia T?xtil da UFRN. Os testes de resist?ncia ao fogo foram realizados no laborat?rio de engenharia de materiais da UFRN. Para medir o desempenho do material, foram realizados ensaios de resist?ncia ? tra??o e flex?o, com as amostras que foram posteriormente analisadas no aparelho de Microscopia Eletr?nico de Varredura (MEV). Os comp?sitos apresentaram bom desempenho mec?nico, e foi observado que a adi??o do agente retardante de chama influenciou nas propriedades mec?nicas, e em alguns casos, deixando o comp?sito mais fr?geis a ruptura. Esses resultados mec?nicos foram submetidos ao teste estat?stico Qui-Quadrado ao n?vel de signific?ncia de 5% para verificar poss?veis diferen?as entre ao grupos de comp?sitos. O teste de flamabilidade foi realizado baseado na norma Underwriter's Laboratory 94 e o material apresentou um resultado satisfat?rio, tendo a sua taxa m?dia de queima (mm/min) diminuindo com o aumento da adi??o do retardante de chamas nos comp?sitos. / Currently, there is a great search for materials derived from renewable sources. The vegetable fibers as reinforcement for polymer matrixes, has been used as an alternative to replace synthetic fibres, being biodegradable and of low cost. The present work aims to develop a composite material with epoxy resin reinforced with curau? fibre with the addition of alumina trihydrate (aluminum hydroxide, Al(OH)3) as a flame retardant, which was used in proportions of 10 %, 20% and 30% of the total volume of the composite. The curau? fibers have gone through a cleaning process with an alkaline bath of sodium hydroxide (NaOH ), parallelized by hand and cut carding according to the default length . They were molded composites with fibers 30cm. Composites were molded in a Lossy Mold with unidirectional fibres in the proportion of 20% of the total volume of the composite. The composites were prepared in the Chemical Processing Laboratory of the Textile Engineering Department at UFRN. To measure the performance of the material, tests for the resistance to traction and flexion were carried out. with samples that were later analyzed in the Electronic Microscopy Apparatus (SEM ). The composites showed good mechanical properties by the addition of flame retardant and in some cases, leaving the composite more vulnerable to breakage. These mechanical results were analyzed by chi-square statistical test at the 5% significance level to check for possible differences between the composite groups. Flammability testing was conducted based on the standard Underwriters Laboratory 94 and the material showed a satisfactory result taking their average burn rate (mm / min) decreasing with increasing addition of the flame retardant composite.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-10T00:17:19Z No. of bitstreams: 1 FranciscoClaudivanDaSilva_TESE.pdf: 104448273 bytes, checksum: 6fc093e63486403fa90fe3c9a04747ab (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-10T23:41:42Z (GMT) No. of bitstreams: 1 FranciscoClaudivanDaSilva_TESE.pdf: 104448273 bytes, checksum: 6fc093e63486403fa90fe3c9a04747ab (MD5) / Made available in DSpace on 2016-06-10T23:41:42Z (GMT). No. of bitstreams: 1 FranciscoClaudivanDaSilva_TESE.pdf: 104448273 bytes, checksum: 6fc093e63486403fa90fe3c9a04747ab (MD5) Previous issue date: 2015-12-14 / A sustentabilidade tem sido cada dia mais um tema em evid?ncia no mundo, atualmente organiza??es t?m buscado estar cada vez mais dentro desta filosofia em seus processos, produtos ou servi?os. No presente trabalho foram fabricados ecocomp?sitos com a fibra animal (l? canina) que atualmente ? descartada no meio ambiente sem nenhum aproveitamento. As fases do projeto consistiram em tratamento inicial das fibras em solu??o alcalina (NaOH) ? 0,05 mols para retirada das impurezas presentes, e desenvolver m?todos para converter estas fibras (refor?o) misturadas com o poliuretano de mamona (matriz) em eco-comp?sito com distintas propor??es (5%, 10%, 15% e 20%). Foram estudadas as propriedades da fibra pela an?lise de MEV, DRX e FTIR. Os comp?sitos foram fabricados em molde por compress?o com dimens?es 30x30x1cm com um tempo de cura de 24 horas. Para caracteriza??o dos comp?sitos foram realizados os seguintes ensaios normatizados: mec?nicos (tra??o, compress?o, dureza shore A), testes absor??o de ?gua, moisture regain e biodegrada??o. As propriedades t?rmicas nas fibras e comp?sitos foram analisadas por TG, DSC, condutividade t?rmica, resistividade, capacidade calorifica, resist?ncia t?rmica e dilatometria. Analisando os resultados destes testes, observou-se que o comp?sito refor?ado com 20% apresentou um melhor comportamento t?rmico em rela??o aos demais comp?sitos e estabilidade dimensional quando comparado aos isolantes t?rmicos comerciais. Sendo tamb?m poss?vel observar um equil?brio na absor??o de umidade dos comp?sitos sendo evidenciado com o seu maior ?ndice de absor??o nesta mesma amostra (20%). As micrografias demonstram as regi?es de intera??o da fibra com o poliuretano com preenchimento dos espa?os vazios. Nos testes de dureza e compress?o podemos identificar que com o aumento do percentual de fibras o material adquire uma maior rigidez fazendo se necess?ria uma maior tens?o utilizada para deforma??o. Portanto mediante os testes realizados nos eco-comp?sitos, o de maior percentual de fibra utilizado como refor?o em sua composi??o obteve melhor desempenho frente aos demais eco-comp?sitos, chegando a valores bem pr?ximos ao do PU. / The Sustainability has been evidence in the world today; organizations have sought to be more and more into this philosophy in their processes, whether products or attendance. In the present work were manufactured eco-composites with animal fiber (dog wool) that is currently discarded into the environment without any use. Project phases consisted on the initial treatment of fibers with alkaline solution (NaOH) at 0.05 mols for removal of impurities, developing methods to convert these fibers (reinforcement) blended with castor oil polyurethane (matrix) in eco-composite with different proportions (5%, 10%, 15% and 20%). Fiber properties were evaluated by analysis of SEM, XRD and FTIR. The composites were produced by compression molding with dimensions 30x30x1cm. For characterization of the composites the following tests were performed: mechanical (tensile, compression, shore hardness A) according the standards and testing water absorption, moisture regain and biodegradation. The analysis of thermal properties on fibers and composites were by TG, DSC, thermal conductivity, resistivity, heat capacity and thermal resistance. Analyzing the results of these tests, it was observed that the composite reinforced with 20% showed a better thermal performance between others composites and dimensional stability when compared to commercial thermal insulation. Also is possible to observe a balance in moisture absorption of the composite being shown with its higher absorption rate in this same sample (20%). The micrographs show the fiber interaction regions with polyurethane to fill the empty spaces. In hardness and compression testing can identify that with increasing percentage of the fiber material acquires a greater stiffness by making a higher voltage is used for forming necessary. So by the tests performed in eco-composites, the highest percentage of fiber used as reinforcement in their composition obtained a better performance compared to the remaining eco-composites, reaching values very close to the PU.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-14T20:19:26Z No. of bitstreams: 1 IgorGuedesReboucas_DISSERT.pdf: 4109459 bytes, checksum: 9d05bc4fe3e1208e2195bfe4405550de (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-15T23:42:40Z (GMT) No. of bitstreams: 1 IgorGuedesReboucas_DISSERT.pdf: 4109459 bytes, checksum: 9d05bc4fe3e1208e2195bfe4405550de (MD5) / Made available in DSpace on 2016-06-15T23:42:40Z (GMT). No. of bitstreams: 1 IgorGuedesReboucas_DISSERT.pdf: 4109459 bytes, checksum: 9d05bc4fe3e1208e2195bfe4405550de (MD5) Previous issue date: 2015-12-17 / Este trabalho consiste na elabora??o de uma Rede Neural Artificial (RNA) com o fim de modelar o comportamento de comp?sitos quando submetidos a carregamento de fadiga. A proposta ? desenvolver e apresentar um modelo misto, que associa uma equa??o anal?tica (Equa??o de Adam) ? estrutura da RNA. Tendo em vista que os comp?sitos geralmente apresentam comportamentos semelhantes quando sujeitos a carregamentos flutuantes, essa equa??o visa estabelecer um padr?o pr?-definido de compara??o para um material gen?rico, a fim de que a RNA ajuste o comportamento de outro comp?sito a esse padr?o. Dessa forma, a RNA n?o precisaria aprender por completo o comportamento de determinado material, pois a Equa??o de Adam faria boa parte do trabalho. Este modelo foi utilizado em duas arquiteturas de rede diferentes, modular e perceptron, com o objetivo de analisar a sua efici?ncia em estruturas distintas. Al?m das diferentes arquiteturas, foram analisadas as respostas geradas a partir de dois conjuntos de dados diferentes ? com tr?s e duas curvas S-N. Esse modelo tamb?m foi comparado com os resultados da literatura especializada, que utilizam uma estrutura convencional de RNA. Os resultados consistem em analisar e comparar algumas caracter?sticas, como a capacidade de generaliza??o, a robustez e os Diagramas de Goodman, desenvolvidas pelas redes. / This work consists basically in the elaboration of an Artificial Neural Network (ANN) in order to model the composites materials? behavior when submitted to fatigue loadings. The proposal is to develop and present a mixed model, which associate an analytical equation (Adam Equation) to the structure of the ANN. Given that the composites often shows a similar behavior when subject to float loadings, this equation aims to establish a pre-defined comparison pattern for a generic material, so that the ANN fit the behavior of another composite material to that pattern. In this way, the ANN did not need to fully learn the behavior of a determined material, because the Adam Equation would do the big part of the job. This model was used in two different network architectures, modular and perceptron, with the aim of analyze it efficiency in distinct structures. Beyond the different architectures, it was analyzed the answers generated from two sets of different data ? with three and two SN curves. This model was also compared to the specialized literature results, which use a conventional structure of ANN. The results consist in analyze and compare some characteristics like generalization capacity, robustness and the Goodman Diagrams, developed by the networks.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-23T20:06:05Z No. of bitstreams: 1 MaraisaCristianeDeOliveiraLeite_DISSERT.pdf: 2733334 bytes, checksum: d086f67ef0d47e95e151ff9ad376bcd7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-27T20:29:13Z (GMT) No. of bitstreams: 1 MaraisaCristianeDeOliveiraLeite_DISSERT.pdf: 2733334 bytes, checksum: d086f67ef0d47e95e151ff9ad376bcd7 (MD5) / Made available in DSpace on 2016-06-27T20:29:13Z (GMT). No. of bitstreams: 1 MaraisaCristianeDeOliveiraLeite_DISSERT.pdf: 2733334 bytes, checksum: d086f67ef0d47e95e151ff9ad376bcd7 (MD5) Previous issue date: 2015-12-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Este trabalho objetiva fabricar e caracterizar um comp?sito hibrido pl?stico, com matriz ? base de resina de poli?ster isoft?lica e tendo como refor?o fibras de vidro e o endocarpo do coco seco (Cocos Nuc?fera Linn) na forma de particulado como carga. O comp?sito foi confeccionado industrialmente na Tecniplas Ind?stria e Com?rcio LTDA. na forma de placa, e o processo de fabrica??o utilizado foi ? lamina??o manual (Hand Lay up). A partir da placa foram preparados corpos de prova para ensaios de densidade volum?trica, absor??o de umidade, tra??o uniaxial nos estados seco e ?mido, e ensaio de flex?o, al?m de estudos sobre o comportamento da fratura gerada nos ensaios mec?nicos por meio do MEV. Todos os ensaios foram feitos de modo a achar as aplica??es mais vi?veis ao comp?sito hibrido fabricado. Nos ensaios de tra??o e flex?o foram analisadas as propriedades de tens?o ?ltima, m?dulo de elasticidade e deforma??o. A partir dos resultados observa-se que o percentual de umidade absorvido foi de 3,03%, um valor razoavelmente alto, dado o intervalo de tempo que ocorreu esta absor??o. A presen?a de umidade no ensaio de tra??o significou uma queda de 19,77% da resist?ncia ?ltima, e 5,26% no m?dulo de elasticidade. Para os ensaios de flex?o obteve-se o valor m?dio de 69,13 MPa de resist?ncia ? flex?o. Os resultados apontam a aplica??o do comp?sito hibrido estudado em estruturas leves, ambientes internos, onde exijam solicita??es de tra??o de baixo/m?dio desempenho, e onde envolvem solicita??es de flex?o. / This work aims to manufacture and characterize a hybrid plastic composite with the matrix isophthalic polyester resin base and having as reinforcing glass fiber and the dry endocarp of coconut (Coco nucifera Linn) in the form of particles as filler. The composite was made industrially in Tecniplas Industry and Trade LTDA. in the form of plate, and was manufactured process made by the manual lamination (Hand Lay Up). From the plate they were prepared test specimens for testing density, water absorption, uniaxial traction in dry and wet states, and testing of bending, as well as studies on the behavior of the generated fractures, macroscopic and microscopic, in mechanical tests through. All tests were performed in order to find the most viable applications the hybrid composite manufactured. The tensile and bending tests were analyzed last tensile properties, elasticity and deformation module. After the studies, it is observed that the percentage moisture absorbed was 3.03%. The presence of moisture in the tensile test meant a decrease of 19.77% from last stand, and 5.26% in the elastic modulus. For bending tests gave an average value of 69.13 MPa flexural strength. The results show the application of hybrid composite studied in lightweight structures, indoors, which require low / medium performance traction demands, and which involve flexural requests.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-06T19:38:09Z No. of bitstreams: 1 JoseRibeiroDeSouzaFilho_TESE.pdf: 4358122 bytes, checksum: 4f7e4f1461183c83e90986ad9b9ed75b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-07T17:36:23Z (GMT) No. of bitstreams: 1 JoseRibeiroDeSouzaFilho_TESE.pdf: 4358122 bytes, checksum: 4f7e4f1461183c83e90986ad9b9ed75b (MD5) / Made available in DSpace on 2016-07-07T17:36:23Z (GMT). No. of bitstreams: 1 JoseRibeiroDeSouzaFilho_TESE.pdf: 4358122 bytes, checksum: 4f7e4f1461183c83e90986ad9b9ed75b (MD5) Previous issue date: 2015-12-18 / Com o surgimento de novas tecnologias, tem crescido a necessidade de utiliza??o de novos materiais, e com isso tem se intensificado pesquisas sobre a obten??o e utiliza??o de materiais provenientes de fontes renov?veis, seja para reduzir os custos de produ??o e/ou impacto ambiental. Nesse contexto, verificou-se que a bainha da palha do coqueiro pode ser aproveitada como mat?ria-prima para a produ??o de um comp?sito que pode ser utilizado como isolante t?rmico e ac?stico. Depois de selecionadas as bainhas do coqueiro foram submetidas a tratamento com solu??o aquosa com 2% de hidr?xido de s?dio (NaOH). O comp?sito mencionado foi produzido com bainha do coqueiro e l?tex natural, com percentuais de bainha nas propor??es 15%, 25% e 35% do volume total do composto. As propriedades f?sico-mec?nicas avaliadas foram: Densidade, Absor??o de ?gua, Teor de Umidade, Microscopia Eletr?nica, Dureza Shore e Resist?ncia ? Tra??o. Al?m dos par?metros j? mencionados, foram determinadas a Condutividade T?rmica, Difusividade T?rmica, Resistividade T?rmica, Calor Espec?fico, Inflamabilidade, bem como a Isola??o Ac?stica, proporcionada pelo comp?sito em estudo. As an?lises foram fundamentadas em normas ABNT, ASTM e UL. Diante dos resultados obtidos, pode-se concluir que o comp?sito produzido a partir da bainha do coqueiro pode ser utilizado como isolamento t?rmico e ac?stico. Com isso, d?-se um fim mais nobre a este material, que na maioria das vezes ? queimado ou descartado inadequadamente no meio ambiente. / With the emergence of new technologies, has grown the need to use new materials, and this has intensified research on the collection and use of materials from renewable sources, is to reduce production costs and / or environmental impact. In this context, it was found that the sheath coconut straw, can be utilized as raw material for the production of a eco-composite that can be used as a thermal and acoustic insulator. After selected from the coconut sheaths were subjected to treatment with aqueous 2 % sodium hydroxide (NaOH). The composite study was produced with the sheath and coconut natural latex, with coconut sheath percentage in the proportions 15%, 25% and 35% of the total compound volume. Physical, thermal and acoustic properties of the composites were analyzed in order to obtain data on the use of viability as thermoacoustic insulation. The CP15 composites, CP25 and CP35 showed thermal conductivity 0.188 W/m.K, 0.155 W/m.K and 0.150 W/m.K, respectively. It can be applied as thermal insulation in hot systems to 200 ? C. The CP35 composite was more efficient as a thermal and acoustic insulation, providing 20% noise reduction, 31% and 34% for frequencies of 1 kHz, 2 kHz and 4 kHz, respectively. The analyzes were based on ABNT, ASTM, UL. Based on these results, it can be concluded that the eco-composite produced the hem of coconut can be used as thermal and acoustic insulation. Thus, it gives a more noble end to this material, which most often is burned or disposed of improperly in the environment.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-22T15:34:02Z No. of bitstreams: 1 MarianaLimaDeOliveira_DISSERT.pdf: 1436779 bytes, checksum: b40fe8dddf1d23473972fa9553244479 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-27T22:37:51Z (GMT) No. of bitstreams: 1 MarianaLimaDeOliveira_DISSERT.pdf: 1436779 bytes, checksum: b40fe8dddf1d23473972fa9553244479 (MD5) / Made available in DSpace on 2016-07-27T22:37:51Z (GMT). No. of bitstreams: 1 MarianaLimaDeOliveira_DISSERT.pdf: 1436779 bytes, checksum: b40fe8dddf1d23473972fa9553244479 (MD5) Previous issue date: 2015-12-29 / Foi estudada a viabilidade do uso do farelo do sabugo de milho para a obten??o de um comp?sito de matriz polim?rica. Foram utilizadas tr?s granulometrias e algumas formula??es entre os elementos constituintes do comp?sito, resina poli?ster e farelo do sabugo de milho e determinada qual a formula??o mais adequada levando-se em conta par?metros mec?nicos e t?rmicos. Para a obten??o do farelo, o sabugo passou pelo processo de secagem em secador solar e posteriormente foi triturado numa forrageira, obtendo-se diferentes granulometria atrav?s de peneiramento. Para a caracteriza??o do comp?sito ser?o determinadas propriedades t?rmicas e mec?nicas. A principal vantagem do comp?sito proposto foi sua baixa densidade, abaixo da relativa a resina, em torno de 1,06 Kg/m? para a formula??o com P? Grosso. O comp?sito apresentou comportamento mec?nico inferior ao da resina para todas as granulometrias e formula??es estudadas. Apresentou resultados melhores para a flex?o, alcan?ando 25,3 MPa para o P? Grosso. O comp?sito tamb?m se demonstrou vi?vel para aplica??es t?rmicas, com condutividade t?rmica inferior a 0,21 W/m, classificando-se como isolante t?rmico. Em termos de homogeneidade da mistura a granulometria mais vi?vel ? a PF 20%, que tamb?m apresentou melhor est?tica e uma melhor processabilidade. Tal comp?sito pode ser utilizado para a fabrica??o de estruturas que n?o requeiram significativa resist?ncia mec?nica, como por exemplo, mesas, cadeiras, pranchas, e prot?tipos solares e e?licos, como fornos e fog?es solares e p?s de aero geradores. / The feasibility of using the corn cob to obtain a polymer matrix composite was studied. To obtain the bran, corncob passed the drying process in a solar dryer, and was subsequently triturated in forage and to obtain the different particle sizes, by sieving. Three different grain sizes were used: fine particles (FP) size between 0,10 and 2mm; sized particles (PM) with sizes between 2,10 and 3,35 mm; large particles (PG) sizes between 3,45 and 4,10 mm. Using 20% of residue relative to the resin, the test samples were constructed for characterization of the composite, taking into account thermal and mechanical parameters. The main advantage of the proposed composite is that it has a low density, below the relative resin, about 1.06 kg / m? for the PG. The composite showed a mechanical behavior less than of the resin to the grain sizes and for all formulations studied. Showed better results for the bending, reaching 25.3 MPa for the PG. The composite also showed be feasible for thermal applications, with thermal conductivity less than 0.21 W / m, ranking as insulation. In terms of homogeneity of the mixture, the most viable grain size is the PF, which also showed improved aesthetics and better processability. This composite can be used to make structures that do not require significant mechanical strength, such as tables, chairs, planks, and solar and wind prototypes, such as ovens and cookers and turbines blades.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-09T22:54:12Z No. of bitstreams: 1 MariaKalionaraDeFreitasMota_TESE.pdf: 2448911 bytes, checksum: 324edc16514bb1c73bf850667ec692d8 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-12T23:50:08Z (GMT) No. of bitstreams: 1 MariaKalionaraDeFreitasMota_TESE.pdf: 2448911 bytes, checksum: 324edc16514bb1c73bf850667ec692d8 (MD5) / Made available in DSpace on 2016-08-12T23:50:08Z (GMT). No. of bitstreams: 1 MariaKalionaraDeFreitasMota_TESE.pdf: 2448911 bytes, checksum: 324edc16514bb1c73bf850667ec692d8 (MD5) Previous issue date: 2016-02-23 / Os materiais comp?sitos surgem da necessidade de materiais mais leves e com maiores resist?ncias mec?nica e t?rmica. As dificuldades de descarte, reciclagem ou reutiliza??o s?o hoje preocupa??es ambientais e por isso objeto de estudo de muitas pesquisas. Nessa perspectiva estudou-se a viabilidade do uso da bucha vegetal (Luffa Cylindrica) para a obten??o de um comp?sito de matriz polim?rica. Foram testadas seis configura??es/formula??es, com 4, 5 e 6 camadas tratadas e n?o tratadas. As buchas foram tratadas em ?gua fervente para retirar ligninas, ceras e impurezas presentes nas fibras, posteriormente secadas em secador solar de exposi??o direta. Para a caracteriza??o do comp?sito foram determinadas propriedades t?rmicas (condutividade, capacidade t?rmica, difusividade e resistividade), mec?nicas (tra??o e flex?o) e fisicoqu?micas (MEV, DRX, densidade, absor??o e degrada??o). Uma das vantagens do comp?sito proposto foi a baixa densidade das fibras, 066 g/cm?, quase metade da matriz de resina poli?ster, produzindo uma densidade m?dia do comp?sito em torno de 1,17g/cm?, inferior em 6,0% em rela??o a matriz. O tratamento realizado nas buchas trouxe aumento na resist?ncia mec?nica do comp?sito e diminui??o da absor??o de umidade. O comp?sito apresentou comportamento mec?nico inferior ao da resina matriz para todas as formula??es. O comp?sito tamb?m demonstrou-se vi?vel para aplica??es t?rmicas, com condutividade t?rmica inferior a 0,159 W/mk, classificando-se como um bom isolante t?rmico. Para todas as formula??es/configura??es ocorreu uma baixa ader?ncia entre fibras e matriz, com fissuras presentes, mostrando fragilidade em fun??o da baixa impregna??o da fibra pela matriz. Tal comp?sito pode ser utilizado para a fabrica??o de estruturas que n?o requeiram significativa resist?ncia mec?nica, como por exemplo, prot?tipos solares, como fornos e fog?es. / Composite materials arise from the need for lighter materials and with bigger mechanical and thermal resistance. The difficulties of discard, recycling or reuse are currently environmental concerns and, therefore, they are study object of much researches. In this perspective the feasibility of using loofahs (Luffa Cylindrica) for obtainment of a polymeric matrix composite was studied. Six formulations, with 4, 5 and 6 treated layers and untreated, were tested. The loofahs were treated in boiling water to remove lignins, waxes and impurities present in the fibers. After that, they were dried in a direct exposure solar dryer. For the characterization of the composite, thermal (thermal conductivity, thermal capacity, thermal diffusivity and thermal resistivity), mechanical (tensile and bending resistance) and physicochemical (SEM, XRD, density, absorption and degradation) properties were determined. The proposed composite has as advantage the low fiber density, which is around 0.66 g/cm? (almost half of the polyester resin matrix), resulting in an average composite density of around 1.17g/cm?, 6.0 % lower in relation to the matrix. The treatment carried out in the loofahs increased the mechanical strength of the composite and decreased the humidity absorption. The composite showed lower mechanical behavior than the matrix for all the formulations. The composite also demonstrated itself to be feasible for thermal applications, with a value of thermal conductivity of less than 0.159 W/m.K, ranking it as a good thermal insulator. For all formulations/settings a low adherence between fibers and matrix occurred, with the presence of cracks, showing the fragility due to low impregnation of the fiber by the matrix. This composite can be used to manufacture structures that do not require significant mechanical strength, such as solar prototypes, as ovens and stoves.