Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-09T23:24:53Z No. of bitstreams: 1 ChristianeSiqueiraDeAzevedoSa_DISSERT.pdf: 2601824 bytes, checksum: 192560f3b8d14a03aa0da8a4f6dc9924 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-11T22:01:19Z (GMT) No. of bitstreams: 1 ChristianeSiqueiraDeAzevedoSa_DISSERT.pdf: 2601824 bytes, checksum: 192560f3b8d14a03aa0da8a4f6dc9924 (MD5) / Made available in DSpace on 2016-03-11T22:01:19Z (GMT). No. of bitstreams: 1 ChristianeSiqueiraDeAzevedoSa_DISSERT.pdf: 2601824 bytes, checksum: 192560f3b8d14a03aa0da8a4f6dc9924 (MD5) Previous issue date: 2015-02-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Os materiais t?xteis inteligentes e funcionais t?m sido amplamente desenvolvidos e pesquisados com a finalidade de serem utilizados em v?rias ?reas da ci?ncia e tecnologia. Esses materiais fibrosos necessitam de diferentes propriedades qu?micas e f?sicas para se tornarem materiais multifuncionais. Com o advento da nanotecnologia, as t?cnicas desenvolvidas t?m sido ferramentas essenciais para caracterizar qualitativamente esses novos materiais. Ultimamente a aplica??o de micro e nanomateriais em substratos t?xteis tem sido objeto de muitas pesquisas. Muitos desses nanomateriais n?o tem sido otimizado, e os custos para sua aplica??o e a polui??o ao meio ambiente vem aumentando, pois ainda n?o existe tratamento de efluentes contento esses nanomateriais. As fibras de soja t?m baixa adsor??o de micro e nanoc?psulas termosenss?veis devido a sua incompatibilidade de suas cargas superficiais. No presente trabalho utilizou-se a s?ntese da quitosana para previamente funcionalizar as fibras de soja. A quitosana ? um polieletr?lito natural apresentando alta densidade de cargas positivas, as fibras de soja apresentam cargas negativas bem como, as micro/nanoc?psulas, com isso a quitosana atua como agente cationizador da fibra. Neste caso a quitosana atua como agente auxiliar cationizador para fixar as microc?psulas termosenss?veis no substrato t?xtil. Para a caracteriza??o do polieletr?lito foram feitas as an?lises do tamanho das part?culas, potencial zeta, bem como as an?lises morfol?gicas (MEV e DRX), an?lises das propriedades t?rmicas (TG), an?lise da Calorimetria Explorat?ria Diferencial (DSC), an?lise por Espectroscopia na Regi?o do Infravermelho com Transformada de Fourier (FTIR), colorimetria via espectro de UV-VIS foram simultaneamente realizadas no substrato utilizado. No potencial zeta e na determina??o do tamanho das part?culas foi observada a estabilidade eletrost?tica da quitosana em torno de 31.55mV e 291,0 nm respectivamente. O resultado obtido com (GD) para o material extra?do de camar?o foi de 70%, que de acordo com a literatura pode ser considerada como quitosana. Para otimiza??o do processo de tingimento foi usado um software estat?stico, o Design expert. A funcionaliza??o do substrato t?xtil com 2% de quitosana apresentou o melhor resultado de K/S, sendo o par?metro utilizado para o planejamento experimental juntamente com as vari?veis, tendo demonstrado a melhor resposta de tingimento na faixa de 2,624 de absorb?ncia. Verificou-se tamb?m que a malha de soja tingida com as nano/microc?psulas termosenss?veis apresentou excelente propriedade de solidez a lavagem, que foi observada ap?s 25 lavagens caseiras e valores significativos de K/S. / Intelligent and functional Textile Materials have been widely developed and researched with the purpose of being used in several areas of science and technology. These fibrous materials require different chemical and physical properties to obtain a multifunctional material. With the advent of nanotechnology, the techniques developed, being used as essential tools to characterize these new materials qualitatively. Lately the application of micro and nanomaterials in textile substrates has been the objective of many studies, but many of these nanomaterials have not been optimized for their application, which has resulted in increased costs and environmental pollution, because there is still no satisfactory effluent treatment available for these nanomaterials. Soybean fiber has low adsorption for thermosensitive micro and nanocapsules due to their incompatibility of their surface charges. For this reason, in this work initially chitosan was synthesized to functionalise soybean fibres. Chitosan is a natural polyelectrolyte with a high density of positive charges, these fibres have negative charges as well as the micro/nanoc?psules, for this reason the chitosan acts as auxiliary agent to cationize in order to fix the thermosensitive microcapsules in the textile substrate. Polyelectrolyte was characterized using particle size analyses and the measurement of zeta potential. For the morphological analysis scanning Electron Microscopy (SEM) and x-Ray Diffraction (XRD) and to study the thermal properties, thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Near Infrared Spectroscopy analysis in the Region of the Fourier Transform Infrared (FTIR), colourimetry using UV-VIS spectrum were simultaneously performed on the substrate. From the measurement of zeta potential and in the determination of the particle size, stability of electrostatic chitosan was observed around 31.55mV and 291.0 nm respectively. The result obtained with (GD) for chitosan extracted from shrimp was 70 %, which according to the literature survey can be considered as chitosan. To optimize the dyeing process a statistical software, Design expert was used. The surface functionalisation of textile substrate with 2% chitosan showed the best result of K/S, being the parameter used for the experimental design, in which this showed the best response of dyeing absorbance in the range of 2.624. It was noted that soy knitting dyed with the thermosensitive micro andnanocapsules property showed excellent washing solidity, which was observed after 25 home washes, and significant K/S values.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-09T23:24:53Z No. of bitstreams: 1 LuizRicardoRodriguesAraujo_DISSERT.pdf: 3739180 bytes, checksum: 537275bf067079ba77fea7de66deff86 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-11T22:14:29Z (GMT) No. of bitstreams: 1 LuizRicardoRodriguesAraujo_DISSERT.pdf: 3739180 bytes, checksum: 537275bf067079ba77fea7de66deff86 (MD5) / Made available in DSpace on 2016-03-11T22:14:29Z (GMT). No. of bitstreams: 1 LuizRicardoRodriguesAraujo_DISSERT.pdf: 3739180 bytes, checksum: 537275bf067079ba77fea7de66deff86 (MD5) Previous issue date: 2015-05-08 / Apresenta-se o estudo comparativo da capacidade de assamento de dois fornos solares tipo caixa, fabricados a partir de um caixote para transporte de equipamentos. Os dois fornos t?m configura??es internas diferentes, predominando o efeito estufa ou a concentra??o da radia??o solar incidente. As principais caracter?sticas dos fornos fabricados s?o seu baixo custo, o reaproveitamento de materiais, os f?ceis processos de fabrica??o e montagem, a simples operacionalidade e a capacidade de assamento de v?rios alimentos simultaneamente. A fabrica??o e a operacionalidade dos fornos estudados podem ser repassados para pessoas de quaisquer n?veis sociais e intelectuais. Foi demonstrada a viabilidade de utiliza??o dos dois fornos para produzir o assamento dos alimentos testados, comprovando-se a supremacia do forno espelhado. Os resultados obtidos para as duas configura??es testadas foram competitivos at? mesmo com o forno convencional a g?s. Produziu-se o assamento de tr?s bolos de 750g cada em apenas 80 minutos. / This research is presented as a comparative study about the baking capacity of two box type ovens, produced from a packing case used to equipment transportation. The two ovens have different internal settings, with the greenhouse effect and the concentration of incident solar radiation as the main parameters of differentiation. The main features of the ovens are the low cost, the reuse of materials, the manufacturing and assembly processes simplified, the easy management and the ability of baking a variety of foods simultaneously. The manufacturing and operation of the ovens can be handled by any social and intellectual level of people. The feasibility of the ovens to bake the tested foods was proved with success, ensuring the supremacy of the mirrored oven. The results obtained for both ovens were competitive even with the conventional gas oven, producing the baking of three cakes with 750g in just 80 minutes.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-09T23:24:53Z No. of bitstreams: 1 MayaraPatriciaGalvaoCoelho_DISSERT.pdf: 2408849 bytes, checksum: 1bd70b2df5eb96dd1157b144481399c7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-11T22:43:11Z (GMT) No. of bitstreams: 1 MayaraPatriciaGalvaoCoelho_DISSERT.pdf: 2408849 bytes, checksum: 1bd70b2df5eb96dd1157b144481399c7 (MD5) / Made available in DSpace on 2016-03-11T22:43:11Z (GMT). No. of bitstreams: 1 MayaraPatriciaGalvaoCoelho_DISSERT.pdf: 2408849 bytes, checksum: 1bd70b2df5eb96dd1157b144481399c7 (MD5) Previous issue date: 2015-02-19 / Diante da evolu??o humana e do aumento populacional, fez-se necess?rio o surgimento de novas fontes de energia, o desenvolvimento de novos produtos e tecnologias. Um desses produtos, fruto da revolu??o industrial e de grande import?ncia para o desenvolvimento da humanidade, ? o petr?leo, uma subst?ncia composta basicamente de hidrocarbonetos que d?o origem a v?rios outros produtos como combust?veis, lubrificantes, pol?meros, solventes, g?s de cozinha, asfalto para estradas, fertilizantes, medicamentos, tintas, dentre outros. No entanto, o manuseio incorreto deste produto pode causar vazamentos e derramamentos que geram danos enormes para o meio ambiente e para a economia. Logo, com a finalidade de contribuir para amenizar est? problem?tica, neste trabalho de mestrado foi efetuada uma intensa pesquisa da poss?vel potencialidade das fibras de Ceiba Pentandra (L.) conhecida como ?Kapok? e Calotropis Procera como bioadsorventes de petr?leo. A escolha destas fibras deve-se a propriedades superficiais como oleof?licas/hidrof?bicas, sua flutuabilidade e ainda, serem pol?meros naturais biodegrad?veis presentes na regi?o nordeste do Brasil. Foi utilizado um planejamento experimental com metodologia de superf?cie de resposta (RSM) com o software Design Expert. Os resultados obtidos se mostraram eficientes estatisticamente, obtendo um R2= 0,9995 para a Calotropis Procera e um R2= 0,9993 para o Kapok no sistema est?tico; j? em sistema din?mico, foi obtido um R2= 0,9996 para a Calotropis e um R2= 0,9991para o Kapok. Ambas as fibras apresentaram uma efici?ncia na adsor??o, removendo mais de 80% do petr?leo da ?gua em estado est?tico e din?mico. / On the basis of human evolution and the population increase was necessary, the emergence of new sources of energy, the development of new products and technologies. One such product, object of the industry revolution and of great importance to the development of humanity is the oil, a substance composed primarily of hydrocarbons which give rise to several other products as fuels, lubricants, polymers, solvents, cooking gas, asphalt for roads, fertilizers, medicines, paints, among other. However, mishandling this product may cause leaks and spills that generate huge damages to the environment and the economy. Soon, with the purpose of contributing to decrease is problematic, in this master's work was carried out an intensive search of the possible potential of the fibers of Ceiba pentandra (L.) "Kapok" and Calotropis Procera as bioadsorbents of petroleum in water. The choice of these fibers is due to surface properties such as oleophylics and hydrophobic, their buoyancy and yet, being biodegradable natural polymers derived from the Brazilian Northeast. This research was used experimental planning with response surface methodology (RSM) with the software Design Expert. The results were statistically efficient, obtaining a R2= 0.9995 for Calotropis Procera and a R2= 0.9993 for Kapok. And that, both fibers showed adsorption efficiency, removing more than 80% petroleum in water static and dynamic state.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-31T22:54:15Z No. of bitstreams: 1 MaxwellSantanaLiborio_DISSERT.pdf: 1626523 bytes, checksum: 50034137e4680e28892b945409b7b1af (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-04T21:38:35Z (GMT) No. of bitstreams: 1 MaxwellSantanaLiborio_DISSERT.pdf: 1626523 bytes, checksum: 50034137e4680e28892b945409b7b1af (MD5) / Made available in DSpace on 2016-04-04T21:38:35Z (GMT). No. of bitstreams: 1 MaxwellSantanaLiborio_DISSERT.pdf: 1626523 bytes, checksum: 50034137e4680e28892b945409b7b1af (MD5) Previous issue date: 2015-03-02 / Nas ultimas d?cadas, a altera??o das propriedades superficiais de materiais tem sido muito utilizada para melhorar suas caracter?sticas tribol?gicas. Contudo, essa melhoria depende do processo, do tempo de tratamento e, principalmente, da espessura desta camada ou do filme superficial. Atualmente, o processo de deposi??o a plasma PVD (Physical vapor Deposition) de Nitreto de Tit?nio (TiN) vem sendo utilizado para aumentar a dureza superficial de materiais met?licos. Por isso, o objetivo deste trabalho foi de propor um m?todo num?rico-experimental para avaliar a espessura filmes (l) de TiN depositados por PVD. Para atingir este objetivo, combinaram-se resultados experimentais de ensaios de dureza (H) com sua simula??o num?rica para estudar o comportamento desta propriedade em fun??o da profundidade de penetra??o m?xima do indentador (hmax) no conjugado filme/substrato. Foram adotadas duas metodologias para determinar a espessura do filme. A primeira combinou os resultados num?ricos da curva H x hmax com sua curva experimental obtida atrav?s do ensaio de indenta??o instrumentado. Esta metodologia foi usada com sucesso em um conjugado de Tit?nio (Ti) revestido por TiN. Uma segunda estrat?gia combinou os resultados num?ricos da curva Hv x hmax com dados experimentais de dureza Vickers (Hv). Esta outra metodologia foi aplica em um conjugado de a?o ferramenta M2 recoberto por TiN. As propriedades mec?nicas dos materiais estudados tamb?m foram determinadas no presente trabalho. As espessuras encontradas para os dois conjugados apresentaram resultados compat?veis com seus dados experimentais. / In recent decades, changes in the surface properties of materials have been used to improve their tribological characteristics. However, this improvement depends on the process, treatment time and, primarily, the thickness of this surface film layer. Physical vapor deposition (PVD) of titanium nitrate (TiN) has been used to increase the surface hardness of metallic materials. Thus, the aim of the present study was to propose a numerical-experimental method to assess the film thickness (l) of TiN deposited by PVD. To reach this objective, experimental results of hardness (H) assays were combined with a numerical simulation to study the behavior of this property as a function of maximum penetration depth of the indenter (hmax) into the film/substrate conjugate. Two methodologies were adopted to determine film thickness. The first consists of the numerical results of the H x hmax curve with the experimental curve obtained by the instrumental indentation test. This methodology was used successfully in a TiN-coated titanium (Ti) conjugate. A second strategy combined the numerical results of the Hv x hmax curve with Vickers experimental hardness data (Hv). This methodology was applied to a TiN-coated M2 tool steel conjugate. The mechanical properties of the materials studied were also determined in the present study. The thicknesses results obtained for the two conjugates were compatible with their experimental data.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-08T23:17:04Z No. of bitstreams: 1 MarcondesMendesDeSouza_TESE.pdf: 3135857 bytes, checksum: 11e52ad3f92073cb71b4e3869890ab67 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-11T23:07:06Z (GMT) No. of bitstreams: 1 MarcondesMendesDeSouza_TESE.pdf: 3135857 bytes, checksum: 11e52ad3f92073cb71b4e3869890ab67 (MD5) / Made available in DSpace on 2016-04-11T23:07:06Z (GMT). No. of bitstreams: 1 MarcondesMendesDeSouza_TESE.pdf: 3135857 bytes, checksum: 11e52ad3f92073cb71b4e3869890ab67 (MD5) Previous issue date: 2015-04-17 / Nos estados da Para?ba e Rio Grande do Norte, no Brasil, as jazidas mais expressivas na produ??o de minerais industriais n?o-met?licos s?o as dos pegmatitos, quartzitos e granitos, que est?o localizadas na regi?o do Serid?. Os munic?pios de V?rzea - PB, Ouro Branco - RN e Parelhas - RN s?o os principais respons?veis pela extra??o de argila, quartzo, micas e feldspato. As empresas de minera??o que atuam na extra??o e beneficiamento dos quartzitos geram grandes volumes de res?duos, constituindo cerca de 90% de SiO2 na sua composi??o qu?mica proveniente do quartzo, que ? um dos constituintes b?sicos nas formula??es das massas cer?micas para a produ??o de revestimento cer?micos. Para tanto, este trabalho avalia o estudo da adi??o de res?duos de quartzito para obten??o do gr?s porcelanato atrav?s da caracteriza??o das mat?rias-primas por FRX, DRX, MEV, AG, ATG e DSC, utilizando cinco formula??es contendo 57% de feldspato, 37% de argila e 6% de res?duos de quartzitos com colora??es diferentes (branco, dourado, rosa, verde e preto), que foram sinterizadas em tr?s temperaturas: 1150?C, 1200?C e 1250?C, com isoterma de 1 hora e taxa de aquecimento de 10? C/min. Ap?s a sinteriza??o, os corpos-de-prova foram submetidos a ensaios de caracteriza??o f?sica como: absor??o de ?gua, retra??o linear, porosidade aparente, massa espec?fica aparente, resist?ncia ? flex?o em tr?s pontos. Os resultados obtidos apontavam para a possibilidade da utiliza??o do res?duo de quartzito em um percentual de 6% de adi??o na massa cer?mica. A utiliza??o de res?duos de quartzito em massa cer?mica proporcionou um produto final com propriedades tecnol?gicas que atendem ?s normas t?cnicas para a produ??o de gr?s porcelanato, sendo a temperatura de 1200?Ca que apresentou melhores resultados. De acordo com os resultados obtidos verificou-se um alto teor de ?xido de ferro no quartzito preto, sendo descartada a utiliza??o do mesmo em gr?s porcelanato por quest?o estrutural, pois o material fundiu a 1250?C. Todas as formula??es dos quartzitos obtiveram baixa absor??o de ?gua quando sinterizadas a 1200?C, obtendo AA entre 0,1% a 0,36% sem terem passado pelo processo de atomiza??o. Nos ensaios de resist?ncia ? flex?o todos os quartzitos encontram-se nos limites de aceita??o, segundo a norma europeia EN 100, superando 27 MPa na sinteriza??o a 1200?C. Com isso, o uso de res?duo de quartzito em massas cer?micas se apresenta como excelente potencial para a produ??o de gr?s porcelanato. / In States of Para?ba (PB) and Rio Grande do Norte (RN), northeast of Brazil, the most significant deposits of non-metallic industrial minerals are pegmatites, quartzites and granites, which are located in Serid? region. Extraction of clay, quartz, micas and feldspars occurs mainly in the cities of V?rzea (PB), OuroBranco (RN) and Parelhas (RN). Mining companies working in the extraction and processing of quartzite generate large volumes of waste containing about 90% SiO2 in their chemical composition coming from quartz that is one of the basic constituents of ceramic mass for the production of ceramic coating. Therefore, this work evaluates the utilization of these wastes on fabrication of high-quality ceramic products, such as porcelain stoneware, in industrial scale. Characterization of raw materials was based on XRF, XRD, GA, TGA and DSC analysis, on samples composed by 57% of feldspar, 37% of argil and 6% of quartzite residues, with 5 different colors (white, gold, pink, green and black). Samples were synthesized in three temperatures, 1150?C, 1200?C and 1250?C, with one hour isotherm and warming-up tax of 10?C/min. After synthesizing, the specimens were submit to physical characterization tests of water absorption, linear shrinkage, apparently porosity, density, flexural strain at three points. The addition of 6% of quartzite residue to ceramic mass provided a final product with technological properties attending technical norms for the production of porcelain stoneware; best results were observed at a temperature of 1200?C. According to the results there was a high iron oxide on black quartzite, being their use in porcelain stoneware discarded by ethic and structural question, because the material fused at 1250?C. All quartzite formulations had low water absorption when synthesized at 1200?C, getting 0.1% to 0.36% without having gone through the atomization process. Besides, flexural strain tests overcame 27 MPa reaching the acceptance limits of the European Directive EN 100, at 1200?C synthesizing. Thus, the use of quartzite residues in ceramic masses poses as great potential for the production of porcelain stoneware.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-07T00:01:05Z No. of bitstreams: 1 PedroHenriqueSalesDaCosta_DISSERT.pdf: 3167327 bytes, checksum: e3758236165e8d3906f6f8f92e8a236b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-09T20:11:14Z (GMT) No. of bitstreams: 1 PedroHenriqueSalesDaCosta_DISSERT.pdf: 3167327 bytes, checksum: e3758236165e8d3906f6f8f92e8a236b (MD5) / Made available in DSpace on 2016-05-09T20:11:14Z (GMT). No. of bitstreams: 1 PedroHenriqueSalesDaCosta_DISSERT.pdf: 3167327 bytes, checksum: e3758236165e8d3906f6f8f92e8a236b (MD5) Previous issue date: 2015-08-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Em muitos casos o passe de raiz ? uma etapa cr?tica da soldagem, uma vez que sua execu??o ? afetada por diversos fatores, tais como varia??o da abertura da junta, ?ngulo do chanfro, dimens?es da face (nariz) da raiz, inclina??o da tocha, velocidade de soldagem e velocidade de alimenta??o. Al?m disso, a escolha do processo de soldagem ? um fator primordial para garantir a execu??o de um passe de raiz com adequadas propriedades mec?nicas e metal?rgicas. Nesse contexto, este trabalho teve como objetivo estudar a viabilidade dos processos de soldagem MIG-P CC+ e TIG-A aplicado ao passe de raiz em chapas de 200 x 200 x 12,75 mm da liga de alum?nio AA 5052. Para tal, foram analisadas configura??es diferentes de soldagem: o tipo de chanfro (em V e em gola com L=2,00 e 3,00 mm) e dois tipos de metais de adi??o (ER 4043 e 5356). Como metodologia de compara??o, foi determinada a mesma corrente de 150 A e taxa de deposi??o do metal de adi??o Va/Vs = 14, foram realizadas 8 combina??es de par?metros, cada uma com 3 repeti??es, totalizando 24 testes, salientando que foi usada apenas a configura??o de chanfro mais adequada para o TIG-A. S?o apresentados resultados da micrografia e microdureza das zonas fundida e termicamente afetada e n?veis de dilui??o para as juntas soldadas com os distintos metais de adi??o, al?m da radiografia. Nas condi??es estabelecidas neste trabalho, pode-se afirmar que o processo TIG-A apresentou melhores resultados em rela??o ao MIG-P CC+. Em rela??o ? configura??o do chanfro, o que se mostrou mais adequado foi o chanfro em V, para ambos os metais de adi??o e processos. N?o ocorreram defeitos como falta de fus?o, mordeduras e rugosidades. Em rela??o aos n?veis de dilui??o, foram constatados maiores valores quando utilizado o processo MIG-P CC+ para o ER 4043, assim como o processo TIG-A na configura??o de chanfro em V. O metal de adi??o ER 4043 apresentou uma quantidade de poros maior em rela??o ao ER 5356, em ambos os processos. Foi observada ? presen?a de um refino de gr?o, al?m de maiores n?veis de dureza em todas as soldas realizadas com o metal de adi??o ER 5356. / In many cases the root pass is a critical step of welding, since its execution is affected by several factors, such as variation of joint opening, chamfer angle, dimensions of the face (nose) root, torch inclination, welding speed and feed speed. Moreover, the choice of the welding process is a key factor to ensure the execution of a root pass with adequate mechanical and metallurgical properties. In this context, this work aimed to study the feasibility of MIG-P CC+ and TIG-A welding processes applied to the root pass in plates of 200 x 200 x 12,75 mm of the AA 5052 aluminum alloy. For this, different configurations of welding were analyzed: chamfer type(V and collar with L=1,0 and 3,00 mm) and two types of addition metals (ER 4043 and 5356). As compared methodology, It was determined the same current 150 A and the deposition rate of addition metal Va/Vs = 14, they were proposed 12combinations of parameters, each with 3repetitions, totaling 36 tests, stressing that It was used only the most appropriate chamfer setting for TIG-A. Results of micrograph and microhardness of fusion and heat affected zones and dilution levels for welded joints with diferente addition metals, beyond radiography. At the established conditions in this work, it can be said that the TIG-A process showed better results in relation to MIG-P CC+. About the chamfer configuration, which was more appropriate was V chamfer, for both addition metals and process. There were no defects such as lack of fusion, bites and roughness. Relative to dilution levels, higher values were observed when used the MIG-P CC+ process for the ER 4043, as well as TIG-A in the V chamfer configuration. ER 4043 addition metal showed a larger amount of pores in relation to the ER 5356, in both process. It was observed the presence of a grain refining, beyond higher hardness levels in all welds made with the ER 5356 addition metal.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-09T23:30:05Z No. of bitstreams: 1 DucianeOliveiraDeFreitas_TESE.pdf: 6906207 bytes, checksum: 2135ed091959cb162bbf7ed88bcb9751 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-09T23:46:53Z (GMT) No. of bitstreams: 1 DucianeOliveiraDeFreitas_TESE.pdf: 6906207 bytes, checksum: 2135ed091959cb162bbf7ed88bcb9751 (MD5) / Made available in DSpace on 2016-05-09T23:46:53Z (GMT). No. of bitstreams: 1 DucianeOliveiraDeFreitas_TESE.pdf: 6906207 bytes, checksum: 2135ed091959cb162bbf7ed88bcb9751 (MD5) Previous issue date: 2015-04-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O uso de nanomateriais na ind?stria t?xtil vem demonstrando destaque nas ?reas de engenharia de superf?cie e acabamento de tecidos planos, malhas, fios e fibras. Os produtos t?xteis, tratados com estes nanomateriais, adquirem novas propriedades como a autolimpeza. Esta propriedade tem como caracter?stica a capacidade de decompor subst?ncias org?nicas, adsorvidas sobre a superf?cie do material; isto ocorre por meio da fotodegrada??o (rea??o qu?mica produzida na presen?a de um fotocatalizador). O di?xido de tit?nio (TiO2) est? entre os nanomateriais mais utilizados como fotocatalizador na ind?stria t?xtil. Diversos m?todos s?o empregados para a deposi??o de TiO2. Um exemplo comum deste tipo de processo para aplica??o em tecidos t?xteis ? a pr?-ativa??o da superf?cie atrav?s de plasma, seguida de imers?o em solu??o sol-gel com TiO2. Neste caso, s?o utilizados elementos qu?micos que elevam os custos do processo, al?m de se tornarem t?xicos. Neste ?mbito, este trabalho prop?e uma t?cnica alternativa para acabamento t?xtil com TiO2. Ela consiste em aspergir sobre o tecido, as nanopart?culas (NPs) de TiO2 dilu?das em ?gua destilada, utilizando um nebulizador pneum?tico a jato de ar. A t?cnica tamb?m utiliza um filme de carbono (Diamond-like carbon - DLC) para reduzir a hidrofilicidade do tecido de algod?o potencializando, assim, o processo de autolimpeza na superf?cie do tecido. As amostras, ap?s a aspers?o, foram secadas em estufa por 5 minutos a 100?C e introduzidas em reator de plasma, com fonte de descarga cont?nua pulsada, para deposi??o do filme de DLC em atmosfera CH4 (g?s metano) em tr?s tempos diferentes de deposi??o: 10, 20 e 30 minutos. A caracteriza??o do material foi realizada por Microscopia eletr?nica de varredura (MEV), Espectroscopia de energia dispersiva (EDS), Espectroscopia Raman, contagem de distribui??o de part?culas, fotodegrada??o por radia??o de luz Ultra Violeta (UV) e an?lise de molhabilidade por m?todo wicking de espalhamento e absor??o de l?quido. Na an?lise da morfologia da superf?cie, os resultados mostraram boa distribui??o das part?culas sobre a amostra. Em rela??o ao tempo de deposi??o do DLC, as amostras tratadas em 10 minutos, apresentaram os melhores resultados tanto para a fotodegrada??o do corante azul metileno sob luz UV, quanto para o espalhamento e absor??o de l?quidos. Esses resultados mostraram que a utiliza??o do nebulizador para depositar TiO2 sobre um material t?xtil ? vi?vel e que o filme de DLC, al?m de funcionar como ancoragem para as NPs, tamb?m diminui a hidrofilicidade do tecido de algod?o sem interromper a a??o de fotodegrada??o do TiO2. Al?m disso, a t?cnica proposta reduz a quantidade de ?gua como ve?culo de deposi??o das NPs, o tempo e custo no processo de acabamento t?xtil. Todos esses aspectos s?o relevantes para a produ??o industrial no momento onde se busca redu??o dos custos aliada ao menor impacto ambiental. / Nanomaterials have received increasing interest in the textile industry, e.g. in engineering surface and textile finishing of woven fabrics, knits, yarns and fibers. Textile materials treated with these nanomaterials acquire new properties like self-cleaning. Self-cleaning is the ability to decompose organic materials adsorbed on surface, which occurs through photodegradation reaction. Titanium dioxide (TiO2) is one of the nanomaterials most used as photocat alysts in textile industry. Several methods have been employed for TiO2 deposition on textile fabrics surfaces. A common example is immerse a fabric to a sol-gel solution with pre-activation of substrate surface by plasma. In this context, we present an alternative technique for textile finishing: TiO2 nanoparticles suspended in distilled water and spr aying on cotton woven fabric sample by using pneumatic air blast nebulizer. Afterwards, the samples were dried in oven at 100?C for 5 minutes. Then, fabric were introduced in the plasma reactor of d.c. pulsed source for DLC film deposition. The plasma atmosphere was composed of CH4 (methane gas) and three different deposition times were employed: 10, 20 and 30 minutes. The samples were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Raman Spectroscopy, wettability analysis by wicking method of spreading and absorption of liquid, count of particles distribution, and photodegradation by UV light radiation. The results of surface morphology analysis showed good distribution of particles on the substrate surface. The samples modified by TiO2 and plasma deposition of DLC film at 10 minutes, had the best results of methylene blue dye degradation in UV light, as well as spreading and absorption of liquids. These results showed that the use of nebulizer to deposit TiO2 on textile material is feasible and the DLC film in addition to anchor TiO2 NPs, decreases the cotton fabric hydrophilicity without interrupting the action of photodegradation of TiO2. Furthermore, the proposed technique reduces the amount of water as a vehicle for depositing the nanoparticles, the time and costs in the t?xtil e finishing process. All these aspects are relevant for industrial production at the moment when it seeks to reduce costs coupled with lower environmental impact.

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 2016-05-10T21:07:59Z No. of bitstreams: 1 LuizGuilhermeVieiraMeiraDeSouza_DISSERT.pdf: 5289218 bytes, checksum: c88882ed7873a6e13af70d302f562b90 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-12T23:55:24Z (GMT) No. of bitstreams: 1 LuizGuilhermeVieiraMeiraDeSouza_DISSERT.pdf: 5289218 bytes, checksum: c88882ed7873a6e13af70d302f562b90 (MD5) / Made available in DSpace on 2016-05-12T23:55:24Z (GMT). No. of bitstreams: 1 LuizGuilhermeVieiraMeiraDeSouza_DISSERT.pdf: 5289218 bytes, checksum: c88882ed7873a6e13af70d302f562b90 (MD5) Previous issue date: 2015-04-23 / ? apresentado o estudo num?rico de um sistema e?lico de convers?o de energia, que consiste de um aerogerador de eixo horizontal instalado no interior de uma envolta difusora com um flange na periferia de sua sa?da, utilizando CFD. A envolta difusora flangeada desempenha o papel de coletar e acelerar o vento, assim aumentando a pot?ncia el?trica gerada pelo aerogerador. De modo a obter uma pot?ncia de sa?da ainda maior, dados encontrados na literatura a respeito de par?metros ?timos para a envolta, tais como ?ngulo de abertura, altura do flange, formato da entrada, etc., foram utilizados para gerar o modelo estudado neste trabalho. Os resultados obtidos com as simula??es foram ?teis para avalia??es dos n?meros de Reynolds, coeficientes de pot?ncia e outros par?metros envolvidos no processo. O torque e velocidade angular do aerogerador tamb?m foram determinados. Como resultado, o aerogerador com envolta difusora flangeada demonstrou um aumento de pot?ncia em rela??o ao aerogerador simples. / It is presented a numerical study, using Computational Fluid Dynamics (CFD), of a wind power conversion system that consists of a horizontal axis wind turbine installed inside of a diffuser shroud with a flange at the exit periphery. The flanged diffuser shroud plays the role of a device for collecting and accelerating the approaching wind, thereby increasing the power generated by the turbine. In order to obtain an even higher power output, data found on literature concerning optimal parameters for the diffuser shroud, such as open angle, flange height, hub ratio and inlet shape, were used to generate the model studied in this paper. The obtained results from computational simulations were useful for evaluations of the criteria adopted for the study and velocities and pressure distributions. Furthermore, it was possible to calculate the axis power produced by the rotor and the mean wind velocities in the radial direction in front of the rotating plane of the blades for the bare wind turbine case and for the shrouded wind turbine case, making it possible to conclude that the proposed system provided a power increase for a given rotor diameter and Wind speed by a factor of 3.74 when compared to the bare Wind turbine configuration.