Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-30T23:20:43Z No. of bitstreams: 1 AlineCristinaMendesDeFarias_TESE.pdf: 9556716 bytes, checksum: 2350df4b9bbb084a66c9da511159a31d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-01T23:15:21Z (GMT) No. of bitstreams: 1 AlineCristinaMendesDeFarias_TESE.pdf: 9556716 bytes, checksum: 2350df4b9bbb084a66c9da511159a31d (MD5) / Made available in DSpace on 2016-06-01T23:15:21Z (GMT). No. of bitstreams: 1 AlineCristinaMendesDeFarias_TESE.pdf: 9556716 bytes, checksum: 2350df4b9bbb084a66c9da511159a31d (MD5) Previous issue date: 2015-07-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A lubricidade do biodiesel interfere no funcionamento normal dos sistemas de inje??o diesel, principalmente dos bicos injetores, reduzindo o desgaste e elevando o tempo de vida da linha de alimenta??o do motor. O m?todo HFRR (High Frequency Reciprocating Rig) ? um ensaio padr?o para avalia??o da lubricidade do diesel/biodiesel (ASTM D6079), consistindo principalmente da medi??o da escara de desgaste impressa na esfera numa sonda de movimento alternado sob alta frequ?ncia. Quando o desgaste se desenvolve, algumas caracter?sticas din?micas do sistema variam, resultando em desvios significativos nos padr?es dos sinais de vibra??o, ac?sticos e de atrito. A aquisi??o e caracteriza??o das assinaturas desses sinais obtidos durante os ensaios tribol?gicos representam uma importante ferramenta n?o intrusiva de avalia??o da lubricidade desses combust?veis, cuja representa??o no dom?nio do tempo nem sempre revelam informa??es triviais, sendo necess?ria sua transforma??o para o dom?nio da frequ?ncia usando a Transformada r?pida de Fourier (FFT) do sinal. A presente tese objetivou desenvolver uma forma din?mica de avalia??o de lubricidade de combust?veis (Diesel S50, ?ster Met?lico de Soja e blendas B10 e B20) em bancada HFRR (contato esfera-disco plano), e melhoria aos referenciais metodol?gicos da ASTM D6079, aplicando t?cnicas de an?lise de sinais (vibra??o e n?vel de press?o sonora) e sua associa??o com par?metros disponibilizados pela norma ASTM D6079 (di?metro da escara de desgaste) com dura??o de 75, 120 e 180 minutos. Os perfis e par?metros de rugosidade e an?lise microsc?pica dos discos foram usados para melhor avaliar a influ?ncia do tempo e do combust?vel na evolu??o do desgaste do disco. Nesta avalia??o, a lubricidade dos combust?veis aumentou com o teor de biodiesel utilizado e diminuiu com o aumento do n?mero de ciclos aplicado. A an?lise temporal e o espectro de frequ?ncia dos sinais demonstraram sensibilidade com a mudan?a do combust?vel, o n?mero de ciclos e, consequentemente, com a evolu??o do desgaste pelo uso prolongado dos combust?veis, estando, assim, correlacionados entre si e com os resultados dispon?veis pela ASTM. / The lubricity of biodiesel interferes in the normal operation of diesel injection systems, especially in nozzles. It can reduce the wear and raise the lifetime of the engine supply line. The method HFRR (High Frequency Reciprocating Rig) is a standard test for evaluation of diesel/ biodiesel lubricity (ASTM D6079). The HFRR lubricity evaluation mainly consists of measuring the printed scar wear on the ball. When wear is developing, some dynamic features of the system vary and it results in significant changes in the patterns of vibration, sound pressure level (SPL) and friction signals. The acquisition and characterization of signatures of these signals obtained during tribological tests are an important non-intrusive tool for evaluating of the lubricity of these fuels, whose representation in the time domain not always reveals trivial information. This requires signal transformation to the frequency domain using the Fast Fourier Transform (FFT) and Short-Time Fourier Transform (STFT) analyses. This thesis aimed to develop a dynamic assessment of lubricity fuels (Diesel S50, Methyl Ester of Soybean and B10 and B20 blends) in HFRR bench (ball-on-flat disk contact), and improving the methodological framework of ASTM D6079 standard by application of signal analysis techniques (vibration and SPL) and its association with parameters provided by ASTM D6079 (wear scar diameter) lasting 75, 120 and 180 minutes. The profiles and topographic parameters of scars and their microscopic analysis were used to further evaluate the influence of the time and fuel in the wear evolution of disk. In this evaluation, the fuel lubricity was influenced by increasing of biodiesel content and decreasing of number of cycles applied. From the temporal and frequency spectrum analysis of the vibration and NPS signals it is shown that both vibration and NPS stablish a relation with fuel lubricity, biodiesel content, number of cycles and parameters of profiles from scar of discs.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-30T23:20:44Z No. of bitstreams: 1 LucemaideBatistaMirandaFerreira_TESE.pdf: 4494748 bytes, checksum: f35753b1191ecb306cd0973efb042a35 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-01T23:33:29Z (GMT) No. of bitstreams: 1 LucemaideBatistaMirandaFerreira_TESE.pdf: 4494748 bytes, checksum: f35753b1191ecb306cd0973efb042a35 (MD5) / Made available in DSpace on 2016-06-01T23:33:29Z (GMT). No. of bitstreams: 1 LucemaideBatistaMirandaFerreira_TESE.pdf: 4494748 bytes, checksum: f35753b1191ecb306cd0973efb042a35 (MD5) Previous issue date: 2015-08-06 / O presente trabalho tem como objetivo fazer uma an?lise das propriedades mec?nicas e do comportamento mec?nico de duas l?minas refor?adas com tecido unidirecional de fibra de curau? com diferentes fra??es volum?tricas, baseado em crit?rios de falha definidos em literatura. Os comp?sitos, que apresentam matriz polim?rica e refor?o com tecido unidirecional de fibra de curau?, foram submetidos a ensaios de tra??o e cisalhamento em uma s?rie de corpos de provas normatizados cuja orienta??o das fibras direcionadas em ?ngulos de 0?, 10?, 20?, 75? e 90? para a l?mina com fra??o volum?trica de 30% e 0?, 30?, 45?, 60?, e 90? para a l?mina com fra??o volum?trica de 22%, para ensaios de tra??o e para ensaio de cisalhamento a orienta??o do ?ngulo do refor?o foi de 90?. Os ensaios foram executados em uma m?quina universal de tra??o e coletados os dados das propriedades mec?nicas dos corpos de prova dos comp?sitos. Estes dados experimentais foram inseridos nas equa??es te?ricas que definem os crit?rios de falha, como tamb?m, tratados graficamente para an?lise dos resultados e compara??o entre os ?ngulos de orienta??o do refor?o. Constatou-se uma grande dispers?o entre os dados experimentais do m?dulo de Elasticidade e do Coeficiente de Poisson em rela??o ao comportamento te?rico principalmente para a l?mina com menor fra??o volum?trica. O comp?sito com orienta??o de refor?o a 0? apresentou a maior resist?ncia ? tra??o em rela??o ?s demais inclina??es para as duas l?minas. No entanto, em rela??o aos crit?rios de falha as l?minas tiveram comportamentos diferentes. Para a l?mina com fra??o volum?trica 30%, os quatro crit?rios estudados nesta Tese apresentaram boa concord?ncia em termos de resist?ncia, mas para a l?mina com fra??o volum?trica de 22%, apenas o crit?rio de Tsai-Will e Hashin apresentaram boa concord?ncia. . / This study aims to analyze the mechanical properties and the mechanical behavior of two laminas reinforced with unidirectional fabric curau? with different fiber volume fractions, based on failure criteria defined in the literature. The composites which have polymeric matrix and reinforcement with unidirectional fabric curaua fiber, were submitted to tensile and shear tests at a series of specimens standardized whose fiber orientation directed at angles of 0?, 10?, 20?, 75? and 90? to the lamina with volume fraction of 30% and 0?, 30 ?, 45 ?, 60 ?, and 90 ? to the lamina with volume fraction of 22% to tensile tests and shear tests the direction of strengthening the angle was 90 ? to the x axis (direction of the applied load). The tests were performed in a universal machine traction and collected the data of mechanical properties of the composite specimens. These experimental data were entered in the theoretical equations that define the failure criteria, as well as graphically treated to analyze the results and compare the enhanced orientation angles. It found major disparities between the experimental data of elastic modulus and Poisson's ratio in relation to the theoretical behavior primarily to the lamina with a lower volume fraction. The composite reinforcement orientation at 0 ? showed the highest tensile strength compared to other inclinations for the two laminas. However, regarding the failure criteria laminas have different behaviors. To the lamina with volume fraction 30%, the four criteria studied in this thesis showed equivalent results in terms of resistance and to the blade with volume fraction of 22%, only the maximum stress criterion was not satisfactory in representing experiemtais data.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:57:09Z No. of bitstreams: 1 BrunoDanielAlvesDoNascimento_DISSERT.pdf: 2697025 bytes, checksum: 8a93610daedd22a97964b68f4766a99b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T20:32:39Z (GMT) No. of bitstreams: 1 BrunoDanielAlvesDoNascimento_DISSERT.pdf: 2697025 bytes, checksum: 8a93610daedd22a97964b68f4766a99b (MD5) / Made available in DSpace on 2016-06-07T20:32:39Z (GMT). No. of bitstreams: 1 BrunoDanielAlvesDoNascimento_DISSERT.pdf: 2697025 bytes, checksum: 8a93610daedd22a97964b68f4766a99b (MD5) Previous issue date: 2015-06-19 / A redu??o no consumo de energia ? o principal requisito a ser satisfeito em sistemas de refrigera??o e condicionamento de ar por compress?o mec?nica de vapor. Em sistemas automotivos essa realidade n?o ? diferente. A an?lise t?rmica nesses sistemas ? de fundamental import?ncia para um bom desempenho do ar-condicionado veicular. Este trabalho tem o objetivo de avaliar as condi??es de utiliza??o do g?s refrigerante R134a (utilizado em ve?culos automotivos), variando a velocidade no eletroventilador do evaporador, comparando a performance do mesmo com o g?s R437a, submetido as mesmas condi??es. Todos os testes foram realizados na unidade de climatiza??o automotiva ATR600, que simula as condi??es t?rmicas do sistema e do habit?culo do ve?culo. O equipamento est? instrumentado para aquisi??o dos dados de temperatura, press?es de alta e baixa e pot?ncia el?trica consumida, para determina??o do coeficiente de performance do ciclo. O sistema foi ensaiado nas rota??es de 800, 1600 e 2400 RPM com carga constante de R134a / R437a, recomendada pelo fabricante. Os resultados mostram que a melhor performance do sistema ocorre na rota??o de 800 RPM para ambos os refrigerantes. / The reduction in energy consumption is the main requirement to be satisfied in refrigeration and air conditioning by mechanical vapor compression system. In automotive system isn?t different. Thermal analyses in these systems are crucial for a better performance in automotive air conditioner. This work aims to evaluate the conditions of use of R134A refrigerant (used in vehicles) and compare with R437A (alternative refrigerant), varying the speed of the electric fan in the evaporator. All tests were performed in automotive air conditioning unit ATR600, simulating the thermal conditions of the system. The equipment is instrumented for data acquisition temperature, condensation and evaporation pressures and electrical power consumed to determine the coefficient of performance of the cycle. The system was tested under rotations of 800, 1600 and 2400 rpm with constant load of R- 134a. It occurred with the same conditions with R437A. Both recommended by the manufacturer. The results show that the best system performance occurs in the rotation of 800 RPM for both refrigerants.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:57:10Z No. of bitstreams: 1 FelipeMoraisFernandesSerafim_DISSERT.pdf: 2615030 bytes, checksum: c5cdd1f3e33cd45acd31d95163c78d6a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T20:57:49Z (GMT) No. of bitstreams: 1 FelipeMoraisFernandesSerafim_DISSERT.pdf: 2615030 bytes, checksum: c5cdd1f3e33cd45acd31d95163c78d6a (MD5) / Made available in DSpace on 2016-06-07T20:57:49Z (GMT). No. of bitstreams: 1 FelipeMoraisFernandesSerafim_DISSERT.pdf: 2615030 bytes, checksum: c5cdd1f3e33cd45acd31d95163c78d6a (MD5) Previous issue date: 2015-11-16 / O trabalho objetiva investigar o uso de uma estrutura de sanduiche h?brida formada com tecido de fibras de kevlar (Kevlar 49), manta de fibras de vidro do tipo E e particulado do endocarpo do coco seco (Cocos Nuc?fera Linn), tendo como matriz a base de resina termofixa de tereftalato de poli?ster para o uso em ?reas de equipamento de prote??o. O processo de fabrica??o adotado foi o de lamina??o manual (hand lay up) para confeccionar a estrutura h?brida. Para caracterizar o comportamento mec?nico e f?sico foi fabricada uma placa de 800x700 mm? do painel h?brido, da qual foram preparados corpos de prova para os ensaios de absor??o de umidade, tra??o uniaxial, densidade volumetrica, impacto (Charpy) e testes bal?sticos. Este ?ltimo foi aplicado para que fosse feito um estudo comparativo da fratura bal?stica causada pela penetra??o do projetil bal?stico de calibre 38 e 380, N?vel I e N?vel III, respectivamente. Houve tamb?m analise do di?metro de entrada e sa?da do projetil, como da ?rea de dano delaminada. Para o ensaio de Impacto (Charpy), foram analisadas a energia absorvida e a caracter?stica da fratura, para, assim, ser analisado o comportamento da configura??o proposta. Todos os testes realizados tem por finalidade a aplica??o nas ?reas de equipamento contra impacto bal?stico, tais como, capacetes; coletes ? prova de bala; blindagens; embalagens de prote??o entre outros itens a serem identificados nesta pesquisa. Os resultados obtidos apontam para aplica??es onde envolvem solicita??es trativas para este material, por?m, o mesmo obteve valores baixos de energia absorvida no ensaio de impacto. No teste bal?stico, houve penetra??o total das placas, mas com significativa ?rea delaminada. / This work aims to study and investigate the use of a hybrid composite polymer formed with blanket aramid (Kevlar 29) fiber blanket flax fiber and particulate dry endocarp of coconut (Cocos nucifera Linn), using as matrix an epoxy resin based thermoset for use in areas of protective equipment. Besides such material is used an aluminum plate, joined to the composite by means of glue based on epoxy and araldite commercial. The manufacturing process adopted was manual lamination (Hand Lay Up) to manufacture the hybrid composite. After the composite is prepared, an aluminum plate is subjected to pressure and glued to cure the adhesive. Layers of veil will also be used to separate the particulate from the linen blanket layer without disturbing the alignment of the fibers of the blankets. To characterize the mechanical and physical behavior was manufactured a plate of 800 x 600 mm of the hybrid composite, which were removed specimens for tests of water absorption to saturation; density; impact test (Charpy) and two test specimens for ballistic testing 220 mm x 200 mm to make a comparative study between the dry state and saturated water absorption and thus see the ballistic performance of these two conditions. The test was applied to make a comparative study of fracture in these two conditions, caused by penetrating ballistic missile (38 and 380). To test the impact (Charpy) will analyze the absorbed energy, fracture appearance and lateral contraction, also in dry condition and saturation of absorbed water, thereby analyzing situations where the impact load is relevant, such as bumps and shocks produced by stone, metal or wooden bars among others. The proposed configuration, along with the tests, has the purpose, application in the fields of equipment against ballistic impact, such as helmets; bullet proof vests; shields; protective packaging and other items to be identified in this research.

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 2016-06-03T23:57:10Z No. of bitstreams: 1 LuizHenriquePinheiroDeLima_DISSERT.pdf: 2055438 bytes, checksum: a2892c7c538f0c5ba015c03438289d3f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T21:59:39Z (GMT) No. of bitstreams: 1 LuizHenriquePinheiroDeLima_DISSERT.pdf: 2055438 bytes, checksum: a2892c7c538f0c5ba015c03438289d3f (MD5) / Made available in DSpace on 2016-06-07T21:59:39Z (GMT). No. of bitstreams: 1 LuizHenriquePinheiroDeLima_DISSERT.pdf: 2055438 bytes, checksum: a2892c7c538f0c5ba015c03438289d3f (MD5) Previous issue date: 2015-09-11 / Os refrigeradores de uso dom?stico s?o equipamentos que apresentam uma parcela significativa do consumo de energia el?trica nas resid?ncias brasileiras. O uso destes equipamentos com baixa efici?ncia energ?tica contribui para o aumento do consumo de energia. A efici?ncia energ?tica de um refrigerador ? fun??o da intera??o o fluido refrigerante e os componentes do ciclo termodin?mico. Altera??es na carga e/ou natureza do refrigerante podem modificar as press?es de condensa??o e/ou evapora??o. A capacidade volum?trica do compressor, a vaz?o m?ssica de refrigerante e a pot?ncia de compress?o s?o par?metros dependentes das press?es de evapora??o e condensa??o. Assim, os dispositivos de expans?o exercem um papel importante no equil?brio destas press?es, sendo fundamentais para o melhor desempenho do ciclo de refrigera??o. A presente pesquisa experimental tem como prop?sito investigar a sensibilidade dos par?metros de desempenho de um refrigerador dom?stico operando com R134a e em diferentes press?es de evapora??o. Para tanto, um refrigerador de pequeno porte foi instrumentado com sensores de temperatura, de press?o e de outras vari?veis de interesse, instalados ao longo do circuito frigor?fico, de modo a permitir o mapeamento t?rmico e a avalia??o dos par?metros de desempenho do equipamento. A varia??o da perda de carga no fluido refrigerante resultante da atua??o da v?lvula de expans?o de ajuste microm?trico modifica a temperatura de evapora??o, influenciando sensivelmente os par?metros de desempenho do ciclo termodin?mico de refrigera??o. / Household refrigerators are equipments that represent a significant portion on the eletricity consumption of Brazilian homes. The use of these devices with low energy efficiency contributes to increase the energy consumption. The energy efficiency of a refrigerator is a function of the interaction between the coolant fluid and the components of the thermodynamic cycle. Changes in load and/or nature of the coolant may modify the condensing and/or evaporation pressures. The volumetric capacity of the compressor, the mass flow of coolant and the compression power are dependent parameters of the condensation and evaporation pressures. Thus, the expansion devices exert an importante role in the balance of these pressures, being fundamental for the better performance of the refrigeration cycle. This experimental research aims to investigate the sensitivity of the performance parameters of a household refrigerator operating with R134a and at different evaporation pressures. Therefore, a small refrigerator was instrumented with temperature, pressure sensors and other variables of interest, installed along the cooling circuit, in order to allow the thermal mapping and the evaluation of the equipment performance parameters. The variation of pressure loss in the coolant fluid resulting from the operation of the expansion valve with micrometric adjustment that modifies the evaporation temperature, influencing significantly the performance parameters of the thermodynamic refrigeration cycle.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:57:10Z No. of bitstreams: 1 RalysonRayalaGoncalvesDeOliveira_DISSERT.pdf: 3856655 bytes, checksum: 34ff8ff848067ea45bdaca75cd3e6f56 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T22:09:14Z (GMT) No. of bitstreams: 1 RalysonRayalaGoncalvesDeOliveira_DISSERT.pdf: 3856655 bytes, checksum: 34ff8ff848067ea45bdaca75cd3e6f56 (MD5) / Made available in DSpace on 2016-06-07T22:09:14Z (GMT). No. of bitstreams: 1 RalysonRayalaGoncalvesDeOliveira_DISSERT.pdf: 3856655 bytes, checksum: 34ff8ff848067ea45bdaca75cd3e6f56 (MD5) Previous issue date: 2015-11-20 / Na ind?stria do petr?leo s?o comumente empregados oleodutos e gasodutos para executar o transporte dos fluidos de produ??o a grandes distancias. As manuten??es desses dutos passam pela an?lise de diversas ferramentas, dentre as mais empregadas atualmente destaca-se as c?lulas de inspe??o de duto, popularmente conhecida como PIG. Dentre as variantes existentes no mercado, o chamado PIG instrumentado possui relev?ncia significativa, visto que atrav?s dos in?meros sensores existentes nele, o equipamento pode detectar falhas ou potenciais de falha ao longo da linha inspecionada. Apesar de sua versatilidade, o PIG instrumentado sofre com varia??es de velocidade, o que prejudica a leitura dos sensores embutidos nele. Como o PIG desloca-se em fun??o da velocidade do fluido de produ??o, uma forma de controlar a velocidade dele ? controlar a vaz?o deste fluido, atrav?s do controle da press?o, reduzindo a velocidade de escoamento do fluxo produzido, resultando na redu??o da produ??o total do fluido nos pr?prios dutos ou com o emprego de um elemento restritivo (v?lvula) instalado nele. A caracter?stica da raz?o vaz?o/perda de press?o de elementos restritivos do tipo orif?cio ? normalmente deduzida da equa??o ideal de energia (equa??o de Bernoulli) e, em seguida, corrigida para as perdas, normalmente por meio de testes experimentais. Assim, com o objetivo de controlar a vaz?o de um fluido que passa pelo PIG, foi desenvolvido uma v?lvula com obturador acionado por meio de solen?ide. Esta configura??o permite uma maior facilidade de controle e estabiliza??o do ajuste de vaz?o, com consequente resposta na quedas de press?o entre ? montante e ? jusante da restri??o. Para defini??o de coeficientes de vaz?o, foi montada uma bancada para realiza??o de ensaios, composta por um duto de quatro polegadas de di?metro interno, uma conjunto de obturadores dispostos em arranjo em uma placa e medidores de press?o para verifica??o de quedas de press?o no ensaio. A linha foi pressurizada e com base nas coletas de queda de press?o foi poss?vel tra?ar uma curva que caracterize o coeficiente de vaz?o do prot?tipo da v?lvula de controle e simular em bancada o funcionamento dela, resultando em redu??es de velocidade do PIG em aproximadamente 68%. / In the Oil industry, oil and gas pipelines are commonly utilized to perform the transportation of production fluids to longer distances. The maintenance of the pipelines passes through the analysis of several tools, in which the most currently used are the pipelines inspection cells, popularly knowing as PIG. Among the variants existing in the market, the instrumented PIG has a significant relevance; acknowledging that through the numerous sensors existing in the equipment, it can detect faults or potential failure along the inspected line. Despite its versatility, the instrumented PIG suffers from speed variations, impairing the reading of sensors embedded in it. Considering that PIG moves depending on the speed of the production fluid, a way to control his speed is to control the flow of the fluid through the pressure control, reducing the flow rate of the produced flow, resulting in reduction of overall production the fluid in the ducts own or with the use of a restrictive element (valve) installed on it. The characteristic of the flow rate/pressure drop from restrictive elements of the orifice plate is deducted usually from the ideal energy equation (Bernoulli?s equation) and later, the losses are corrected normally through experimental tests. Thus, with the objective of controlling the fluids flow passing through the PIG, a valve shutter actuated by solenoid has been developed. This configuration allows an ease control and stabilization of the flow adjustment, with a consequent response in the pressure drops between upstream and downstream of the restriction. It was assembled a test bench for better definition of flow coefficients; composed by a duct with intern diameter of four inches, one set of shutters arranged in a plate and pressure gauges for checking the pressure drop in the test. The line was pressurized and based on the pressure drop it was possible to draw a curve able to characterize the flow coefficient of the control valve prototype and simulate in mockup the functioning, resulting in PIG speed reduction of approximately 68%.

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 2016-06-10T00:17:19Z No. of bitstreams: 1 RicardoPiresDeSouza_TESE.pdf: 6120519 bytes, checksum: 9fff267c4280206b4148045fe28e44aa (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-10T23:50:18Z (GMT) No. of bitstreams: 1 RicardoPiresDeSouza_TESE.pdf: 6120519 bytes, checksum: 9fff267c4280206b4148045fe28e44aa (MD5) / Made available in DSpace on 2016-06-10T23:50:18Z (GMT). No. of bitstreams: 1 RicardoPiresDeSouza_TESE.pdf: 6120519 bytes, checksum: 9fff267c4280206b4148045fe28e44aa (MD5) Previous issue date: 2015-12-03 / Defeitos superficiais em pe?as de a?os oneram os custos das industrias de fundi??o devido a necessidade de retrabalhos. Os moldes de areia s?o os mais utilizados em industrias de fundi??o e um dos grandes respons?veis por proporcionar os defeitos superficiais. Este estudo tem como objetivo otimizar os n?veis das vari?veis do processo de moldagem visando minimizar a ocorr?ncia de defeitos superficiais nas pe?as de a?o fundidas em moldes de areia de s?lica ligados quimicamente por processo de cura a frio. Na metodologia utilizou-se o planejamento de experimentos com parcelas subdivididas, sendo considerados no estudo os fatores de porcentagem de resina na formula??o do molde, adi??o de ?xido de ferro, tipo de tinta, m?todo da aplica??o de tinta, quantidade de camadas de tinta, utiliza??o de ar quente nos moldes e tempo de espera do molde antes do vazamento. Foram analisados como vari?veis respostas os defeitos de eros?o, inclus?o de areia, penetra??o, porosidade e acabamento superficial. Foram realizados ensaios de resist?ncia ? tra??o para avaliar a influ?ncia dos fatores nos par?metros mec?nicos e para os par?metros microestruturais foram realizadas as an?lises de difra??o de raios X, microscopia eletr?nica de varredura (MEV) e an?lises t?rmicas (TG/DSC/dilatometria). Os resultados elucidam que para o defeito de eros?o, o ?nico fator significativo, com n?vel de confian?a de 95%, foi o tipo de tinta, sendo que a tinta ? base de alumina obteve resultados superiores. Para o defeito de inclus?o de areia, houve tr?s fatores significativos, sendo os melhores resultados alcan?ados com a tinta ? base de alumina aplicados com spray e a utiliza??o de ar quente no molde antes do vazamento do metal. Para o defeito de penetra??o, houve quatro fatores significativos, sendo os melhores resultados alcan?ados com 0,8% de resina e adi??o de ?xido de ferro na formula??o do molde, com a tinta sendo aplicada com pincel e tempo de espera de 24 horas antes do vazamento. Para o defeito de porosidade, com n?vel de confian?a de 95%, n?o houve fatores significativos. Para o defeito de acabamento superficial, os melhores resultados foram alcan?ados com 0,8% da resina na formula??o do molde e aplica??o da tinta com pincel. Visando obter os n?veis dos fatores que otimizem todos os defeitos simultaneamente, efetuou-se uma m?dia ponderada dos resultados de cada tipo de defeito, concluindo-se que os melhores n?veis dos fatores foram: 0,8% de resina e adi??o de ?xido de ferro na formula??o da molde, aplica??o de duas camadas de tinta aplicadas com pincel ou spray, com a utiliza??o de ar quente no molde antes do vazamento e 24 horas de espera do molde pronto antes do vazamento. Esses n?veis dos fatores otimizados foram utilizadas em um experimento de confirma??o que ratificaram os resultados obtidos, auxiliando para a redu??o dos retrabalhos e consequentemente na redu??o dos custos das pe?as de a?o fundidas. / Surface defects on steel parts borne costs of smelting industries due to the need of rework. Sand molds are frequently used in foundry industries and largely responsible for providing surface defects. This study aims to optimize the levels of the molding process variables to minimize the occurrence of surface defects in steel castings in silica sand molds chemically linked by cold cure process. The methodology used the experimental design with split plot, being considered in the study the resin percentage factors in the mold formulation, addition of iron oxide, type of paint, the paint application method, amount of ink layers, use of hot air along the lines and waiting time of the mold before casting. They were analyzed as response variables erosion defects, sand inclusion, penetration, porosity and surface finish. Tensile strength tests were performed to evaluate the influence of factors on mechanical parameters and the microstructural parameters were carried out the analysis of X-ray diffraction, scanning electron microscopy (SEM) and thermal analysis (TG / DSC / dilatometry). The results elucidate that for the faulty erosion, the only significant factor with a 95% confidence level was the type of ink and the ink alumina-based superior results obtained. For the sand inclusion of defect, there were three significant factors, with best results obtained with alumina-based paint and spray applied using hot air in the mold before casting the metal. For the defect penetration, there were four significant factors, the best results being achieved with 0.8% of resin and addition of iron oxide in the molding formulation, the paint being applied by brush and standby time of 24 hours before leak. For the defect porosity with a 95% confidence level, no significant factors. For the defect surface finish, the best results were achieved with the 0.8% formulation of the resin in the mold and application of the paint brush. To obtain the levels of the factors that optimize all defects simultaneously, we performed a weighted average of the results of each type of fault, concluding that the best levels of the factors were: 0.8% resin and addition of iron oxide in the formulation of the template, application of two coats of paint applied with a brush or spray, using hot air in the mold before casting and 24 hours of waiting ready the mold before casting. These levels of the optimized factors were used in an experiment to confirm that ratified the results, helping to reduce rework and consequently reducing costs of cast steel parts.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-14T20:19:26Z No. of bitstreams: 1 EriemAllyneMedeirosAzevedo_DISSERT.pdf: 6333576 bytes, checksum: 4fb198cb10ff3117dbd15b989910b143 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-15T23:30:13Z (GMT) No. of bitstreams: 1 EriemAllyneMedeirosAzevedo_DISSERT.pdf: 6333576 bytes, checksum: 4fb198cb10ff3117dbd15b989910b143 (MD5) / Made available in DSpace on 2016-06-15T23:30:13Z (GMT). No. of bitstreams: 1 EriemAllyneMedeirosAzevedo_DISSERT.pdf: 6333576 bytes, checksum: 4fb198cb10ff3117dbd15b989910b143 (MD5) Previous issue date: 2015-12-17 / Embora que eficiente do ponto de vista t?cnico, as camadas de argamassa que constituem o revestimento tradicional de alvenaria (chapisco, embo?o e reboco) apresentam-se em contradi??o com as novas tecnologias construtivas e m?todos mais eficientes de consumo e racionaliza??o da obra. Do ponto de vista ambiental, o aproveitamento de res?duos em novos comp?sitos para a constru??o civil tem sido uma vertente de estudos em crescimento na comunidade cient?fica, podendo vir a ser uma solu??o econ?mica, em alguns casos. Assim sendo, essa pesquisa prop?e o desenvolvimento de uma argamassa para Revestimento Decorativo Monocamada (RDM), para aplica??o em fachadas, produzida em canteiro, incorporando res?duo de vidro temperado (RVT) na matriz ciment?cia, como substituto parcial do agregado. Para tanto, adotou-se a rela??o aglomerante/agregado de 1:6 (em volume), ?ndice de consist?ncia de 250mm ? 20, teores de substitui??o da areia por res?duo de vidro em 20%, 50% e 80%, e rela??o ?gua/cimento vari?vel em diversos tra?os. Foram utilizados dois aditivos, um polim?rico, ? base de estireno butadieno, e outro qu?mico, al?m da adi??o mineral de s?lica ativa e de pigmento inorg?nico nas cores vermelho, amarelo e azul. Foram realizados ensaios mec?nicos para a massa no estado fresco e endurecido, assim como para o revestimento aplicado sobre alvenaria, de modo a demonstrar a viabilidade do material. Al?m disso, verificou-se a adequabilidade do RDM ao ambiente constru?do, por meio de ensaios t?rmicos. Os resultados demonstram a exequibilidade do RDM proposto com valores expressivamente superiores, quando comparado ?s normatiza??es. Assim sendo, o estudo apresenta-se a comunidade cient?fica como um incentivo ao uso das inova??es tecnol?gicas na constru??o, aumentando o leque de alternativas dispon?veis para a produ??o habitacional, com a proposi??o de um material que alcan?a as funcionalidades pretendidas e obt?m ganho ambiental, podendo ser adotado em canteiros de obras, em contrapartida as argamassas industrializadas. / Although efficient from a technical point of view, mortar layers that make up the traditional masonry coating (slurry mortar, plaster and plaster) have to be in contradiction with the new construction technologies and more efficient methods of consumption and work rationalization. From an environmental point of view, the recovery of waste into new composites for the building has been a growing strand of studies in the scientific community, may prove to be a cost-effective solution in some cases. Thus, this research proposes the development of a mortar Decorative Coating Monolayer (RDM), for use in facades, produced on site, incorporating tempered glass waste (RVT) in the cement matrix, as a partial substitute for aggregate. Therefore, we adopted the binder respect / aggregate of 1: 6 (by volume), consistency index 250mm ? 20, sand substitution levels of glass waste 20%, 50% and 80% and relative water / cement varied in many traits. Two additives were used, a polymer, styrene-butadiene-based, and other chemical, besides mineral and silica fume inorganic pigment in colors red, yellow and blue. Mechanical tests were carried out on fresh pasta and hardened, as well as for the applied coating on masonry, so as to demonstrate the feasibility of the material. In addition, it verified the adequacy of the RDM built environment by means of thermal tests. The results demonstrated the feasibility of the proposed RDM with significantly higher values when compared to norms, especially the dash-added replacement content of 20% and addition of pigment in red. Therefore, the study shows the scientific community as an incentive to the use of technological innovations in construction, increasing the range of alternatives available for housing production, with the proposition of a material that achieves the desired functionality and obtain environmental gain, and may be adopted on construction sites as an alternative industrialized mortars.