Dissertations / Theses on the topic 'SBS'
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García, González Rafael. "Etude du comportement sous déformation de copolymères à blocs SBS et SBM à morphologie lamellaire." Lyon, INSA, 2006. http://theses.insa-lyon.fr/publication/2006ISAL0045/these.pdf.
Full textWe have study the structure-properties relation of SBS and SBM black copolymers, where S is the polystyrene, B the polybutadiene and M the poly(methyl-methacrylate), These materials belong to the category of the lamellar "nana structured materials ". We studied the mechanical properties of oriented films in "linear" and in "non linear" conditions. We put in evidence the strain's effects in the microstructure evolution according to the orientation of the applied stress. We used some complementary experimental techniques as the transmission electronic microscopy and optic, the infrared dichroisme, the small angles X ray scattering, the analysis of the stress-strain curves, the measures of DMA. The most interesting results concern the modification of the oriented system's microstructure under strain observed in-situ through the infrared dichroisme and the X-rays scattering, the first shows the structural changes to the level of the chains conformations, and the second allowed us to analyze the structural modifications to the levels of the nanostructured domains. In this way we give account of the evolutions of the texture and the interrelationship with the mechanical behavior. As we could note the mechanical behavior proved to be very different according to the lamellae orientation in relation to the main axis of the solicitation
García, González Rafael Séguéla Roland Cavaillé Jean-Yves. "Etude du comportement sous déformation de copolymères à blocs SBS et SBM à morphologie lamellaire." Villeurbanne : Doc'INSA, 2006. http://docinsa.insa-lyon.fr/these/pont.php?id=garcia_gonzalez.
Full textNogueira, Helton Pereira 1986. "Compósitos baseados em grafite/grafite reconstituído e elastômero SBS." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248755.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: As cargas de carbono, tais como grafite, nanotubos de carbono, fulerenos e mais recentemente o grafite tem atraído a atenção de inúmeros pesquisadores, que buscam formas de aproveitar suas excepcionais propriedades elétricas no desenvolvimento de compósitos com potenciais aplicações nas áreas de sensores eletroquímicos, células solares, barreira eletromagnética entre outras. Neste trabalho teve-se como objetivo o desenvolvimento de compósitos baseados em poli(estireno-co-butadieno-co-estireno) ¿ SBS e as cargas de carbono, grafite e grafite. Para tanto, o grafite foi obtido pela oxidação do grafite empregando-se a metodologia de Hummers, seguida de redução por hidrazina. Os compósitos de grafite e "grafite¿ foram preparados por mistura mecânica e por casting de soluções em diferentes solventes na faixa de composição de 0,5 a 10 % em massa de carga. O processamento mecânico resultou em compósitos que apresentaram comportamento mecânico dependente do tipo e quantidade de carga. Porém, esses compósitos apresentaram-se como isolantes elétricos devido a não formação de uma rede de percolação. A matriz de SBS nos compósitos obtidos por casting apresentou morfologia dependente do solvente empregado, o que se deve aos parâmetros de solubilidade dos solventes e dos blocos de poliestireno e polibutadieno do SBS, e a dispersão da carga pela matriz foi mais uniforme do que no caso de compósitos preparados por mistura mecânica, promovendo uma melhora nas propriedades mecânicas e conferindo propriedades de condução elétrica
Abstract: Carbon fillers such as graphite, carbon nanotubes, fullerenes and currently graphene have attracted the attention of many researchers, due to their exceptional and useful electrical properties for the development of composites with potential applications in electrochemical sensors, solar cells, electromagnetic barrier, and so on. The objective of the herewith work is the development of composites made up of poly(styrene-co-butadiene-co-styrene) ¿ SBS and carbon fillers (graphite or graphene). The graphene was obtained by oxidation of the graphite by the Hummers¿ method, followed by hydrazine¿s reduction. The graphite and graphene - based composites were prepared by melt compounding and by solvent casting using different organic solvents in a composition range of 0,5 to 10% in weight of filler. The results showed that the melt compounding produced composites with mechanical properties dependent on the type and amount of filler. Also, these composites behave as electrical insulators due to the absence of percolation thresholds. The morphology of SBS matrix in the composites obtained by solvent casting is determined by the organic solvent, more specifically by the interaction paramenter of solvent and of the polybutadiene and polystyrene blocks of the SBS. The filler dispersion throughout the matrix in the composites obtained by solvent-casting was more uniform than the dispersion level in the composites obtained by melt compounding. Therefore, the first materials showed higher mechanical performance and electrical conducting
Mestrado
Físico-Química
Mestre em Química
Contreras, Exequiel, Trond Karlsen, and Juan Fco Urmeneta. "Plan de Negocios para la Empresa "SBS Consulting"." Tesis, Universidad de Chile, 2005. http://www.repositorio.uchile.cl/handle/2250/114372.
Full textNo disponible a texto completo
La compañía “SBS Consulting” (SBS = “Social Balance Solutions” en inglés y “Soluciones Balance Social” en castellano) será una empresa consultora especializada en gestión de personas, ubicada en Santiago de Chile. La Compañía proveerá servicios especializados de medición del nivel de compromiso, grado de motivación, satisfacción y actitudes de los empleados respecto de la empresa en que trabajan. La compañía también proveerá asesoría de análisis de los resultados de los servicios de medición que realice y asesoría en la implementación de mejoras. Este servicio de medición será entregado en forma periódica, de tal forma que los efectos de las mejoras que se implementen y otros cambios sociales sean detectados oportuna y adecuadamente. La técnica de medición estará basada en una metodología simple y única desarrollada y perfeccionada por el Sr. Juan Fco. Urmeneta a través de su trabajo como gerente de Recursos Humanos en la Asociación Chilena de Seguridad (ACHS) con una dotación de 3.600 trabajadores aproximadamente distribuidas en todas las regiones del país. ACHS es la principal mutualidad privada del país, administradora del seguro contra accidentes del trabajo y enfermedades profesionales, que entrega servicios de prevención de riesgos, salud ocupacional preventiva y curativa y pago de las prestaciones económicas a los trabajadores, que sufren un infortunio laboral. La empresa “SBS Consulting” cooperará con ACHS y ofrecerá sus servicios a las empresas asociadas de tamaño mediano y grande. La empresa “SBS Consulting” al disponer dentro de sus fundadores al Sr. Urmeneta, aprovechará en forma importante su experiencia adquirida durante más de 20 años administrando el Balance Social en una gran empresa con sucursales a lo largo de todo el país. La metodología ha sido denominada “Balance Social” y ha demostrado disponer de una gran eficiencia para ayudar en el aumento de la productividad de las personas, ahorro de costos asociados a la gestión de personas (Ej. Compensaciones y Entrenamiento, entre otros) disminución de costos de reclutamiento, retención de empleados claves, como también mejoras sustanciales en el nivel de reputación de las empresas, dónde esta metodología se ha aplicado, en forma profesional, con el apoyo decidido de la alta dirección de las mismas. ACHS ha sido reconocida dentro de las 25 mejores empresas para trabajar en Chile, en 3 oportunidades en los últimos 4 años y como la empresa N° 1 de las empresas calificadas dentro del ranking el mejor lugar de trabajo para las mujeres, el 2003 y la N° 3 el 2004. El activo uso de la metodología aportada por el Balance Social por la administración de la ACHS, se estima que ha sido la causa fundamental que le ha permitido lograr estas prestigiosas distinciones, entre otras, y alcanzar la más alta productividad del sistema mutual en forma reiterada. Esta metodología ha sido implementada en dos empresas clientes de la ACHS, cinco han solicitado el servicio y varias otras (más de veinte) han hecho ver su interés en recibir este servicio. En consecuencia, existe un mercado potencial más que razonable para crear una empresa que otorgue el servicio de confección del Balance Social.
Markotsis, Martin G. School of Chemical Engineering & Industrial Chemistry UNSW. "Morphological studies of sbs based interpenetrating polymer networks." Awarded by:University of New South Wales. School of Chemical Engineering and Industrial Chemistry, 2005. http://handle.unsw.edu.au/1959.4/32833.
Full textMachado, Ronaldo Zamiro. "Asfalto modificado com polimero SBS para pavimentos drenantes." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267009.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: O polímero SBS - Estireno-Butadieno-Estireno tem sido muito empregado para modificar o asfalto, tanto para pavimentação como para aplicações industrial. Nessa pesquisa foi abordado o estudo do asfalto modificado com polímeros SBS, apresentando comportamento melhor que asfalto convencional, mostrando-se como o polímero se comporta ao ser misturado com o asfalto e quais características são melhoradas. O asfalto modificado com polímero SBS tem uma vida útil muito superior ao asfalto convencional, ressaltando os pavimentos drenantes, que pelos seus vazios por onde escoam a água oferece maior segurança, durabilidade, conforto, menos custos com manutenção, tempo ganho com viagens mais rápidas, menos estresse, vidas poupadas, e com tudo isso, alertar as autoridades governamentais e concessionárias de rodovias que é necessário investirem mais com esses materiais de melhor qualidade, visto que na Europa e Estados Unidos já se apiicam muito o asfalto modificado com SBS. Porém foi verificado também que nem todos os trechos das rodovias podem ser usados os pavimentos drenantes e quais os pavimentos então que devem ser usados nesses trechos. Foi feito também um comparativo entre custos e benefícios de asfaltos modificados com polímero e asfaltos convencionais
Abstract: The polymer SBS - Styrene-Butadiene-Styrene has been very employed to modify the asphalt, for paving and for industrial applications. In that research the study of the asphalt was approached modified with polymer SBS, presenting better behavior than I asphalt conventional, being shown as the polymeric behaves when being mixed with the asphalt and which characteristics are gotten better. The asphalt modified with polymeric SBS it has an useful life very superior to the conventional asphalt, pointing out the drain pavements, that for your emptiness through where it drains the water it offers larger safety, durability, comfort, less costs with maintenance, time branch with trips faster, less stress, saved lives, and with all this to alert the government authorities and concessionary of highways that it is necessary to invest more with those materials of better quality, because in Europe and United States it is already applied a lot the asphalt modified with SBS. However it was also verified that nor all spaces of the highways can be used the drain pavements and which the pavements then that should be used in those spaces. It was also made a comparative one between costs and benefits of asphalts modified with polymeric and conventional asphalts
Mestrado
Ciencia e Tecnologia de Materiais
Mestre em Engenharia Química
Abreu, Flávia Oliveira Monteiro da Silva. "Blendas de polipropileno com elastômeros termoplásticos tipo SBS e SEBS." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2004. http://hdl.handle.net/10183/4517.
Full textLucena, Maria. "Caracterização química e reológica de asfaltos modificados por polímeros." reponame:Repositório Institucional da UFC, 2005. http://www.repositorio.ufc.br/handle/riufc/2080.
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Neste trabalho foi realizado o estudo da caracterização quimica e reologica do cimento asfaltico produzido recentemente no pais, oriundo de petroleo do Campo Fazenda Alegre, no estado do Espirito Santo. Para efeito de comparação, tambem foram estudados os asfaltos da refinaria Vale do Paraiba e os estrangeiros arabe e venezuelano. Os asfaltos foram modificados por incorporação dos polimeros SBS e EVA, e os efeitos resultantes da modificação foram avaliados. Os parâmetros investigados visaram a avaliação de problemas usuais como: deformação permanente, trincas termicas e oxidação. Os polimeros foram caracterizados atraves de termogravimetria e calorimetria exloratoria diferencial e por espectroscopia no infravermelho. Os asfaltos puros e modificados foram caracterizados por espectroscopia no infravermelho, ressonância magnetica nuclear, calorimetria exploratoria diferencial, termogravimetria e cromatografia de permeação em gel. A composição quimica foi realizada atraves do fracionamento SARA e teor de enxofre. Ensaios empiricos como ponto d amolecimento, penetração e retorno elastico tambem foram realizados. As propriedades reologicas foram avaliadas através da viscosidade absoluta e de ensaios dinâmico-mecânicos. O envelhecimento oxidativo dos asfaltos foi avaliado a partir da analise dos espectros no infravermelho e de ressonância magnética nuclear, alem da variação do modulo complexo de cisalhamento dinâmico. Observou-se que os asfaltos brasileiros diferem em relação aos teores de carbonos aromáticos, quando comparados com o asfalto árabe. Alem disso, apresentam comportamento diversos frente à presença de oxigênio. Nos asfaltos modificados pos SBS, o ensaio de calorimetria exploratória diferencial mostrou uma diminuição na transição vítrea do material. A presença do SBS aumentou a resistência do asfalto ao processo oxidativo. A adição do SBS e do EVA provocou um aumento da viscosidade do asfalto de forma não linear indicando que os polímeros não são aditivos inertes. O comportamento Newtoniano não foi verificado para os ligantes modificados. Ensaios dinâmicos-mecânicos demonstraram que o SBS elevou o grau de desempenho dos ligantes. Os ensaios com as aparas da industria de calçados (EVA), indicaram uma melhoria na elasticidade do ligante.
Sahlberg, Bo. "Indoor Environment in Dwellings and Sick Building Syndrome (SBS) : Longitudinal Studies." Doctoral thesis, Uppsala universitet, Arbets- och miljömedicin, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-172769.
Full textLucena, Maria da ConceiÃÃo Cavalcante. "Chemical and rheological characterization of an asphalt cement(AC)modified polymers." Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1417.
Full textThis work presents a study on chemical and rheological characterization of an asphalt cement (AC) recently produced in Brazil, originated of petroleum of the field of Fazenda Alegre at the state of EspÃrito Sa nto. A second Brazilian petroleum and also a foreign one were also studied, and their respective asphalts were compared to the Fazenda Alegre AC. The effect of polymers such as SBS and EVA on the chemical and rheological behavior of the investigated ACs was also object of the study. Typical pavement distresses were considered, such as permanent deformation, thermal cracking and oxidation. The polymers were examined using therm ogravimetry and differential scanning calorimetry and also infrared spectroscopy. Base and modi fied asphalt cements were characterized by infrared spectroscopy, nucl ear magnetic resonance, thermogravimetry, differential scanning calori metry and gel permeation chromatography. The chemical composition was found by the SARA method a nd the sulfur amount. Empirical tests such as softening point, penetration and elastic recovery were also performed. Rheological properties were determined by the absolute viscosity and dynamic mechanical analyses. The oxidative aging of asphalts was analyzed by the infrared and nuclear magnetic resonance as well by the variati on of complex shear modulus. The observed structural characteristics show ed that the Brazilian asphalt has a different structure when compared to foreign asphalts, evidenced by a different amount of aromatic carbon. In addition, the asphalts showed different beha vior when exposed to oxidative conditions. The differential scanning calorimetry results showed a decrease in glass transition temperatures in the polymer modi fied asphalts. The effect of SBS and EVA were also observed in the viscosity measurem ents. An increase in the absolute viscosity and a Non-Newtonian behavior was observe d. Therefore, polymers acted as non-inert additives. Dynamic mechanical analyses demonstrated that SBS increases the binder performance grade. The analyses performed in the asphalts modified by the residue of sandalâs industry showed an improvement in elasticity.
Fernández, Villalba Omar A., and Salinas Edgardo G. Cáceres. "Evaluación del comportamiento mecánico de mezclas SMA y Superpave empleando asfalto modificado con Polímero SBS (Estireno-Butadieno-Estireno)." Bachelor's thesis, Universidad Ricardo Palma. Programa Cybertesis PERÚ, 2007. http://cybertesis.urp.edu.pe/urp/2007/fernandez_oa/html/index-frames.html.
Full textCarlesso, Gabriela Ceccon. "Estudo do comportamento de mistura asfáltica modificada por nanoargila e polímero SBS." reponame:Repositório Institucional da UFSC, 2017. https://repositorio.ufsc.br/xmlui/handle/123456789/178976.
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No Brasil, o desenvolvimento e o estudo de misturas asfálticas de alto desempenho são justificados em virtude do elevado contingente de defeitos precoces identificados nas rodovias, que contrastam com a notável importância do meio de transporte rodoviário para o País. A partir deste contexto, este trabalho tem como objetivo a avaliação do comportamento reológico e a previsão de desempenho de uma mistura asfáltica modificada simultaneamente por nanoargila e por polímero SBS. Com esta finalidade, foi adaptado um procedimento de laboratório para a modificação de um ligante asfáltico convencional, por meio do qual a nanoargila e o polímero foram incorporados à matriz asfáltica em teores de 3% e de 2%, respectivamente. Posteriormente, a mistura produzida com o ligante modificado (3% NA + 2% SBS) foi investigada em relação à dosagem, à ação deletéria da água, à deformação permanente, ao módulo e à fadiga (aparato 4 pontos) e a simulações numéricas de estruturas de pavimentos. Os resultados foram comparados àqueles obtidos por Melo (2014) e por Marcon (2016), que avaliaram misturas asfálticas análogas, porém produzidas com ligante convencional (CAP 50-70), modificado somente por nanoargila (3% NA) e somente por SBS (SBS 60/85). Como resultado, o estudo de dosagem indicou um teor de ligante de projeto equivalente ao obtido para a mistura produzida com CAP 50-70 e intermediário se comparado àqueles obtidos para as misturas 3% NA e SBS 60/85. Na avaliação do efeito da ação deletéria da água e do fenômeno de deformação permanente, a mistura 3% NA+ 2% SBS mostrou-se superior às demais. No estudo reológico, apresentou módulos complexos relativamente elevados e os menores valores de ângulo de fase. Os resultados dos ensaios de resistência à fadiga, entretanto, mostraram o comportamento superior da mistura SBS 60/85, seguido pelo comportamento das misturas 3% NA+ 2% SBS, 3% NA e convencional. Contudo, com base nas simulações numéricas, evidenciou-se que a substituição de revestimentos com as misturas convencional, 3% NA e SBS 60/85 por revestimentos com a mistura 3% NA+2% SBS é tecnicamente adequada e também pode ser economicamente viável. Desta maneira, tendo em vista o comportamento da mistura modificada por nanoargila e SBS, evidenciado ao longo desta pesquisa, conclui-se que a mesma possui potencial para proporcionar melhorias ao setor rodoviário brasileiro.
Abstract : In Brazil, the development and study of high-performance asphalt mixtures are justified because of the high contingency of early distresses identified on roads, which contrast with the remarkable importance of road transportation to the country. From this context, this work aims to evaluate the rheological behavior and to predict the performance of an asphalt mixture simultaneously modified by nanoclay and SBS polymer. For this purpose, a laboratory procedure was adapted for the modification of a conventional asphalt binder whereby nanoclay and polymer were incorporated into the asphalt matrix in amounts of 3% and 2%, respectively. Subsequently, the mixture produced with the modified binder (3% NA + 2% SBS) was investigated in relation to design, to deleterious effects of water, to permanent deformation, to modulus and fatigue (four point bending test) and to numerical simulations of pavement structures. The results were compared to those obtained by Melo (2014) and by Marcon (2016), who evaluated similar asphalt mixtures but these produced with conventional binder, with binder modified only by nanoclay (3% NA) and with binder modified only by SBS (SBS 60/85). As a result, the dosage study indicated a level of project binder equivalent to that obtained for the mixture with CAP 50-70 and intermediate if compared to those obtained for the mixtures 3% NA and SBS 60/85. In the evaluation of the deleterious action of water effect and the phenomena of permanent deformation, the mixture 3% NA + 2% SBS showed to be superior to the others. In the rheological study, it presented relatively high complex modulus and the smallest phase angle values. The results of the fatigue strength tests, however, demonstrated the superior behavior of the mixture SBS 60/85 followed by the behavior of the mixtures 3% NA + 2% SBS, 3% NA and conventional. However, based on the numerical simulations, it has been found that the replacement of surfaces with conventional mixtures, 3% NA and SBS 60/85 by surfaces with the mixture 3% NA + 2% SBS is technically appropriate and can also be economically viable. Thus, considering the behavior of the mixture modified by nanoclay and SBS evidenced throughout this study, it is concluded that it has potential to provide improvements to Brazilian road sector.
Miles, Prudence E. "Teachers' use of multiplatform educational screen content: The case of Australia's SBS." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/107547/3/Prudence%20Miles%20Thesis.pdf.
Full textWaldman, Walter Ruggeri. "Interação entre processos degradativos na blenda de polipropileno e poliestireno compatibilizada com SBS." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248659.
Full textTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Doutorado
Quimica Inorganica
Doutor em Ciências
Pachamango, Rodríguez Ana, Rojas Roxana Pacheco, and Tinco Giomar Ruiz. "Plan de auditoría interna a ser presentado ante la SBS para su autorización." Master's thesis, Universidad del Pacífico, 2018. http://hdl.handle.net/11354/2287.
Full textCui, Zhanwu. "Use of binder rheology to predict the cracking performance of SBS-modified mixture." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001328.
Full textRossato, Jéssica Helisa Hautrive. "Obtenção e estudo de blendas poliméricas de ABC com copolímero em bloco SBS." reponame:Repositório Institucional da UFABC, 2016.
Find full textDissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Nanociências e Materiais Avançados, 2016.
Blendas de poli(acrilonitrila-estireno-butadieno) (ABS) com modificadores de impacto tipo estireno-butadieno-estireno (SBS) foram obtidas para melhorar ainda mais a resistência ao impacto e melhorar a processabilidade de determinados tipos de ABS. Neste trabalho o objetivo foi à obtenção de blendas ABS/SBS e a investigação do comportamento de resistência ao impacto em função da temperatura. As blendas foram obtidas por extrusão de três diferentes tipos de ABS com diferentes conteúdos de SBS. Foram caracterizadas as propriedades de fluxo, as propriedades reológicas, as propriedades mecânicas e a morfologia de fratura dos materiais obtidos. Concluiu-se que não ocorreu a tenacificação do ABS com adição dos conteúdos de SBS, com exceção das blendas ABS 1 com mais de 10% em massa de SBS. Isto mostrou a influência das características e da composição dos ABS e do SBS, e do processamento no comportamento mecânico e na morfologia obtida pela blendas, além da influência do conteúdo em massa de SBS adicionado. As análises das morfologias de fratura mostraram que as blendas de ABS 1 com mais de 10% em massa de SBS possuem um tamanho de partículas menor que nas blendas ABS 2/SBS e ABS 3/SBS, e também uma melhor distribuição das partículas. Nos resultados dos ensaios de tração notou-se um aumento no alongamento na ruptura com o aumento do conteúdo de SBS nas blendas, com uma pequena diminuição do módulo de elasticidade e na tensão no escoamento. Porém, a adição do copolímero em bloco fez com que houvesse uma melhora na processabilidade nas blendas que foi observado nos ensaios de MFI, reometria capilar e reometria de torque.
Blends of poly(acrylonitrile-styrene-butadiene) (ABS) with impact modifiers type styrene-butadiene-styrene (SBS) were obtained to further improve the impact resistance and improving processability of certain types of ABS copolymer. In this work, the objective was to obtain of ABS/SBS polymer blends and the investigating the behavior of the impact resistance versus temperature. The blends were extruded from different types of ABS with different SBS content. Were characterized the flow properties, rheological properties, mechanical properties and fracture morphology of the materials. Concludes that there wasn¿t toughening of ABS with addition of SBS content, except ABS 1/SBS blends with more than 10 w.t% of SBS. This showed the existence dependency characteristics and composition of ABS and processing in the mechanical behavior and morphology of the blends obtained, besides the influence of the content of SBS added. The analysis of fracture morphology showed that blends of ABS 1 copolymer with more than 10 w.t% of SBS having a less particle size than in the ABS 2/SBS blends and ABS 3/SBS blends, and better distribution of the particles. In the results of tensile tests were noted an increase in elongation at break with increasing content of SBS in the blend, with a small decrease in the elastic modulus and yield strength. However, the addition of block copolymer had caused an improvement in processability in the blends, which was observed in the MFI tests, capillary rheometer and torque rheometer.
Zegarra, Jorge Rodolfo Escalante. "Avaliação de misturas produzidas com ligantes asfálticos peruanos convencional PEN 60/70 e modificados por polímero SBS tipo I 60/60 e PG 76-22." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18143/tde-26042007-173415/.
Full textThe main goal of this work is the evaluation of the behavior of conventional peruvian asphalt binder AC PEN 60/70 and SBS polymer-modified asphalts I 60/60 and PG 76-22, when used in hot-mix asphalt (HMA), under both conditions with and without short-term aging. It aims also to establish the asphalt binder performance grade (PG), which is based on the weather conditions, for different peruvian regions. The peruvian asphalt binders were submitted to conventional and Superpave laboratory tests: penetration, softening point, Brookfield viscosity, flash point, elastic recovery, storage stability, rolling thin film oven test (RTFOT), pressure aging vessel (PAV), dynamic shear rheometer (DSR) and bending beam rheometer (BBR). For the evaluation of mechanical properties 196 specimen were sumitted to Marshall, indirect tensile strength under static loading, indirect tensile strength under static loading after induced moisture, resilient modulus under dynamic diametric compression, static and dynamic creep and fatigue tests. The result show that polymer-modified asphalt binder improve rheological characteristic, in terms of thermal susceptibility and resistance to aging, and also improve the asphalt mixtures behavior, which was verified in all of the mechanical tests and after the structural analysis performed with the Elsym5 program, for all of the short-term aging conditions studied in this work.
Amaral, Simonne da Costa. "Estudos de misturas asfálticas densas com agregados do estado do Pará, utilizando asfalto convencional (CAP-40) e asfalto modificado com polímero SBS (BETUFLEX B 65/60)." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-07012003-194218/.
Full textThis research intends to analyze the advantages of hot-mix asphalt mixtures composed by polymer modified binder and gravel in relation to those made with conventional binder. To achieve the objective, there were compacted seventy five specimens with conventional binder and seventy five specimens with SBS polymer modified binder (BETUFLEX B 65/60) and were performed Marshall tests, static creep (40oC) tests, indirect tensile strength tests and resilient modulus by indirect tensile (25oC) tests. The results of Marshall and tensile strength tests showed a better performance of the polymer modified asphalt mixes than that presented by the conventional asphalt ones. The results from the relation of resilient modulus by indirect tensile and indirect tensile strength tests probably showed that the modified asphalt mixes have the best performance. The elastic strains from static creep tests also showed a better performance of the polymer modified mixes in three of the five binder contents, however, the others properties from static creep tests like as total strain, viscoplastic strain and creep modulus showed that the conventional asphalt mixes have the best performance.
Kappe, Philip. "Design and investigation of the emission dynamics of a mode locked SBS-laser oscillator." Phd thesis, [S.l.] : [s.n.], 2006. http://opus.kobv.de/ubp/volltexte/2006/1151.
Full textTomÃ, Luisa GardÃnia Alves. "Efeito da adiÃÃo de nanoargilas e nanocompÃsitos argila/SBS no desempenho de ligantes asfÃlticos." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=12991.
Full textCoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
O presente trabalho trata do desenvolvimento de aditivos nanoestruturados como materiais potencialmente Ãteis para melhorar o desempenho de ligantes na pavimentaÃÃo asfÃltica. Foram preparados e utilizados como aditivos em composiÃÃes variadas: argilas organofÃlicas montmorilonita, vermiculita e CloisiteÂ, copolÃmero estireno-butadieno-estireno (SBS) e nanocompÃsitos SBS/CLO5% e SBS/OVMT5%. Os nanocompÃsitos polimÃricos foram produzidos por meio da tÃcnica de intercalaÃÃo por soluÃÃo. O objetivo foi melhorar as propriedades fÃsicas e reolÃgicas do ligante e, desta forma, contribuir para sua estabilidade ao armazenamento, para sua maior resistÃncia ao envelhecimento oxidativo e para a reduÃÃo da sua susceptibilidade tÃrmica. Os nanomateriais foram caracterizados por difraÃÃo de raios-x (DRX) e por espectroscopia no infravermelho por transformada de Fourier (FTIR). Os ligantes puros e modificados foram avaliados, quanto Ãs suas propriedades reolÃgicas, atravÃs de ensaios em reÃmetro de cisalhamento dinÃmico (DSR). As tÃcnicas de caracterizaÃÃo estrutural (FTIR), termogravimetria (TGA) e envelhecimento simulado em estufas Rolling Thin Film Oven Test (RTFOT), alÃm dos ensaios reolÃgicos realizados em um DSR, tambÃm foram utilizados para avaliar o desempenho dos ligantes na presenÃa dos aditivos nanoestruturados. Os resultados evidenciam que os ligantes modificados resultaram no aumento do mÃdulo complexo (G*) e na reduÃÃo do Ãngulo de fase (δ), o que significa maior resistÃncia destes à deformaÃÃo permanente. A viscosidade, a penetraÃÃo e a suscetibilidade tÃrmica dos mesmos foram adequadas aos limites estabelecidos pela AgÃncia Nacional do PetrÃleo GÃs Natural e BiocombustÃveis (ANP). As propriedades reolÃgicas dos ligantes asfÃlticos (LA) modificados com os nanocompÃsitos foram comparÃveis Ãs do LA modificado com 4,0% de SBS, identificando uma reduÃÃo de custos, dado o potencial de substituiÃÃo de polÃmero pela argila. A presenÃa da OVMT melhorou a estabilidade à estocagem do LA modificado com SBS, resultado este importante, visto que a separaÃÃo de fases à um dos maiores obstÃculos ao uso do SBS na pavimentaÃÃo.
The present work deals with the development of nanostructured additives as potentially useful materials to improve the performance of asphalt binders in paving. They were prepared and used as additives in various compositions: organophilic montmorillonite clay, vermiculite and CloisiteÂ, styrene-butadiene-styrene copolymer (SBS), as well as SBS/CLO5% and SBS/OVMT5% nanocomposites. The polymeric nanocomposites were produced by the technique of intercalation solution. The aim of that was to improve the physical and the rheological properties of the binder and thus to contribute for their storage stability, to improve their resistance to oxidative aging and to reduce their thermal susceptibility. Nanomaterials were characterized by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Pure and modified asphalt binder (AB) were evaluated for their rheological properties using a dynamic shear rheometer (DSR). The structural characterization technique (FTIR) spectroscopy, thermogravimetric analysis (TGA) and simulated aging in the Rolling Thin Film Oven Test (RTFOT), in addition to rheological measurements performed on a DSR, were also used to estimate the AB performance in the presence of nanostructured additives. The results show that the modified asphalt binder revealed an increase of the complex modulus (G*) and a reduction in the phase angle (δ), which means a higher resistance of them to permanent deformation. Their viscosity, penetration and thermal susceptibility were in accordance to the limits established by the National Agency of Petroleum, Natural Gas and Biofuels. The rheological properties of asphalt binders (AB) modified with nanocomposites were similar to those modified with SBS 4.0%, which identifies a reduction in costs, taking into account the possibility of replacing the polymer by clay. The presence of OVMT improved the storage stability of the SBS modified AB, which is an important result, since phase separation is a major obstacle to the use of SBS in paving.
Fernandes, Mônica Romero Santos. "Efeitos de aditivo tipo óleo e enxofre na reologia de asfaltos modificados com SBS." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/25410.
Full textThe use of polymer modified asphalts has grown significantly in the last decades due to the increase in traffic density, axle loading in vehicles and tyre pressure. These binders favor the increase of pavement life and the reduction of its maintenancement costs. The most used polymer for asphalt modification is styrene-butadiene-styrene blocked copolymers. This thesis evaluated the effects of different compatibilizers and crosslinkers on rheological behavior of styrene-butadiene-styrene copolymer modified asphalt binders, as well as the influence of its structure, linear or radial. Binder’s characteristics were determined by conventional analysis and tests in dinamic shear rheometer. Data obtained provided evidence of the positive effect of sulfur as crosslinker in modified binders properties, with high tan ō reduction, complex modulus increase and deformation reduction after application of cyclic loads, characteristics that turn possible the existence of pavements with greater rutting and fatigue resistance. It was also verified the shale oil efficacy as a compatibilizer agent, providing an excellent polymer dispersion inside asphalt matrix and a stable storage binder at high temperatures. This oil can be considered as a technical available option to aromatic oil presently in use at pavement industry.
Guimarães, José Marcos Faccin. "Concreto asfáltico drenante em asfaltos modificados por polímero SBS e borracha moída de pneus." reponame:Repositório Institucional da UFSC, 2013. http://repositorio.ufsc.br/xmlui/handle/123456789/100844.
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A pesquisa estuda as propriedades mecânicas quanto a desagregação, permeabilidade e deformação permanente dos concretos asfálticos drenantes modificados por polímero SBS e borracha moída de pneus na condição com e sem ciclagem de água. Os granulares utilizados foram de origem granítica oriundos da Empresa Vogelsanger em Palhoça # SC e os ligantes de elevada consistência (CAP 30/45) fornecidos pela Refinaria Duque de Caxias (REDUC) e modificados a fim de atender o objetivo da pesquisa pela Empresa CBB Asfaltos em Curitiba # PR. Utilizou-se o CAP 30/45 com a intenção de obter misturas mais resistentes ao elevado tráfego que provoca o aumento da deterioração das rodovias e modificados para aumentar ainda mais essa resistência. A modificação caracterizou-se pela adição de 4% de polímero SBS por já ter sido tema de outras pesquisas e 20% de borracha moída de pneus pelo apelo ambiental, sendo que tal percentagem foi utilizada pois é a adotada pelas curvas granulométricas descontínuas que caracterizam as misturas drenantes. Para a realização de ambas as misturas, para que sejam comprovadamente drenantes, devem ter volume de vazios acima de 20% e permeabilidade com velocidade de escoamento acima de 0,6 cm/s e além disso, possuírem desagregação inferior a 25% e deformação permanente inferior a 10% para que não haja afundamentos nas trilhas de roda. A razão de estudar as condições das misturas com e sem ciclagem, é verificar o comportamento dessas misturas tanto em pista seca quanto com pista úmida ou molhada. Mas acima de tudo, o estudo busca desenvolver um bom pavimento que proporciona conforto, economia e segurança o que o pavimento drenante oferece por não haver a formação da hidroplanagem, viscoplanagem, reflexão luminosa, névoa d#água, irregularidades, graças à eliminação da lâmina d#água
The research studies the mechanical properties as to disintegration, permeability and permanent deformation of drainage asphalt concretes modifieds for polymer SBS and ground rubber tires in the condition with and without water cycling. The granulars used are of granitic origin from the Vogelsanger Firm in Palhoça - SC and the binders of high consistency (CAP 30/45) were provided by Duque de Caxias Refinery (REDUC) and modifieds for the purpose accord the objective of the research by CBB Asphalt Firm in Curitiba - PR. Was used himself the CAP 30/45 with the intention of obtaining mixtures more resistant to high traffic which causes the increase of the deterioration of the highways and modifieds to further increase this resistence. The modification was characterized himself by the addition of 4% of polymer SBS for already have been theme of other researchs and 20% of ground rubber tires by environmental appeal, being that such percentage was used because is adopted by the discontinuous granulometric curves that characterize the draining mixtures. For the realization of both mixtures, so that are provenly draining, must have void volume above than 20% and permeability with flow velocity above than 0,6 cm/s and furthermore, will possess disintegration less than 25% and permanent deformation less then 10% so that no there sags in the wheel tracks. The reason for study the conditions of mixtures with and without water cycling, is check the behavior of these mixtures both in dry runway as with moist or wet runway. But above all, the study search to develop a good paviment that provides comfort, economy and safety which the drainage paviment provides for have not the formation of hydroplaning, viscoplanagem, light reflection, water mist, irregularities, due to elimination of water depth
Tomé, Luisa Gardênia Alves. "Efeito da adição de nanoargilas e nanocompósitos argila/SBS no desempenho de ligantes asfálticos." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/10833.
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The present work deals with the development of nanostructured additives as potentially useful materials to improve the performance of asphalt binders in paving. They were prepared and used as additives in various compositions: organophilic montmorillonite clay, vermiculite and Cloisite®, styrene-butadiene-styrene copolymer (SBS), as well as SBS/CLO5% and SBS/OVMT5% nanocomposites. The polymeric nanocomposites were produced by the technique of intercalation solution. The aim of that was to improve the physical and the rheological properties of the binder and thus to contribute for their storage stability, to improve their resistance to oxidative aging and to reduce their thermal susceptibility. Nanomaterials were characterized by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Pure and modified asphalt binder (AB) were evaluated for their rheological properties using a dynamic shear rheometer (DSR). The structural characterization technique (FTIR) spectroscopy, thermogravimetric analysis (TGA) and simulated aging in the Rolling Thin Film Oven Test (RTFOT), in addition to rheological measurements performed on a DSR, were also used to estimate the AB performance in the presence of nanostructured additives. The results show that the modified asphalt binder revealed an increase of the complex modulus (G*) and a reduction in the phase angle (δ), which means a higher resistance of them to permanent deformation. Their viscosity, penetration and thermal susceptibility were in accordance to the limits established by the National Agency of Petroleum, Natural Gas and Biofuels. The rheological properties of asphalt binders (AB) modified with nanocomposites were similar to those modified with SBS 4.0%, which identifies a reduction in costs, taking into account the possibility of replacing the polymer by clay. The presence of OVMT improved the storage stability of the SBS modified AB, which is an important result, since phase separation is a major obstacle to the use of SBS in paving.
O presente trabalho trata do desenvolvimento de aditivos nanoestruturados como materiais potencialmente úteis para melhorar o desempenho de ligantes na pavimentação asfáltica. Foram preparados e utilizados como aditivos em composições variadas: argilas organofílicas montmorilonita, vermiculita e Cloisite®, copolímero estireno-butadieno-estireno (SBS) e nanocompósitos SBS/CLO5% e SBS/OVMT5%. Os nanocompósitos poliméricos foram produzidos por meio da técnica de intercalação por solução. O objetivo foi melhorar as propriedades físicas e reológicas do ligante e, desta forma, contribuir para sua estabilidade ao armazenamento, para sua maior resistência ao envelhecimento oxidativo e para a redução da sua susceptibilidade térmica. Os nanomateriais foram caracterizados por difração de raios-x (DRX) e por espectroscopia no infravermelho por transformada de Fourier (FTIR). Os ligantes puros e modificados foram avaliados, quanto às suas propriedades reológicas, através de ensaios em reômetro de cisalhamento dinâmico (DSR). As técnicas de caracterização estrutural (FTIR), termogravimetria (TGA) e envelhecimento simulado em estufas Rolling Thin Film Oven Test (RTFOT), além dos ensaios reológicos realizados em um DSR, também foram utilizados para avaliar o desempenho dos ligantes na presença dos aditivos nanoestruturados. Os resultados evidenciam que os ligantes modificados resultaram no aumento do módulo complexo (G*) e na redução do ângulo de fase (δ), o que significa maior resistência destes à deformação permanente. A viscosidade, a penetração e a suscetibilidade térmica dos mesmos foram adequadas aos limites estabelecidos pela Agência Nacional do Petróleo Gás Natural e Biocombustíveis (ANP). As propriedades reológicas dos ligantes asfálticos (LA) modificados com os nanocompósitos foram comparáveis às do LA modificado com 4,0% de SBS, identificando uma redução de custos, dado o potencial de substituição de polímero pela argila. A presença da OVMT melhorou a estabilidade à estocagem do LA modificado com SBS, resultado este importante, visto que a separação de fases é um dos maiores obstáculos ao uso do SBS na pavimentação.
Taira, Claudio. "Avaliação do desempenho em laboratório de misturas asfálticas densas utilizando asfalto convencional (CAP-20) e asfalto modificado com polímero SBS (BETUFLEX B 65/60)." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-09052016-111805/.
Full textThe purpose of this study is to evaluate the performance of asphalt mixes using conventional binder and the same binder modified with SBS polymer (Betuflex B 65/60) based on Marshall test, static and dynamic creep tests, indirect tensile strength test and resilient modulus by indirect tensile test, with the same granulometric composition and different binders contents. In Marshall test, polymer modified asphalt mixes presented better stability performance than conventional asphalt mixes in most of binders contents, despite of the higher flow values obtained for all binders contents. The static creep test results indicated that this test does not clearly distinguish the effect of polymer in asphalt mixes while the results of dynamic creep test indicated the opposite, i. e., polymer modified asphalt mixes deformations are smaller for most of the asphalt binders contents studied. The indirect tensile strength test results showed a better performance of modified asphalt. The results of resilient modulus by indirect tensile test at 25°C showed smaller values for modified asphalt, while the results at 5ºC and 40ºC did not show differences between the asphalt mixes. The mathematics modelling of the creep and recovering curves according to constitutive equations of some basic visco- elastic models showed a difference between the values of some constitutive elements in both cases, dynamic and static tests.
Na, Jong-Ha. "Introducing the digital news system into a TV newsroom : a case of SBS, South Korea." Thesis, University of Sheffield, 2012. http://etheses.whiterose.ac.uk/14995/.
Full textMazzucco, Mateus De Lorenzi Cancelier 1981. "Estudo de híbridos de montmorilonitas organicamente modificadas e ABS compatibilizados com copolímeros SEBS ou SBS." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266723.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: Este trabalho apresenta um estudo sobre a relação entre estrutura e propriedades de híbridos de montmorilonitas organicamente modificadas (MMTO) e terpolímero de acrilonitrila-butadieno-estireno (ABS), compatibilizados com o copolímero de estirenoetileno- butadieno-estireno (SEBS) ou de estireno-butadieno-estireno (SBS) preparados via intercalação no estado fundido em extrusora de rosca-dupla. Quatro formulações de híbridos foram propostas segundo um planejamento fatorial de experimentos 22 para estudar o efeito dos fatores compatibilizante (SEBS e SBS) e composição da MMTO (Cloisite 30B e mistura Cloisite 30B+Cloisite 20A (1:1)). A mistura binária de argilas foi proposta para verificar a viabilidade em balancear o caráter hidrofílico e hidrofóbico dos surfactantes destes dois tipos de argilas. As etapas de processamento foram: 1) Preparação de quatro concentrados na proporção mássica de 49,5: 40: 10: 0,5 de ABS/argila/compatibilizante/antioxidante em misturador interno; 2) Diluição para 4% em massa de MMTO; 3) extrusão do composto; 4) Granulação em moinho e moldagem por injeção dos corpos de prova. O efeito destes fatores e suas interações foram avaliados através de análises de difração de raios-X (DRX), microscopia eletrônica de varredura (MEV), microscopia eletrônica de transmissão (MET), termogravimetria (TGA), calorimetria diferencial de varredura (DSC), ensaios de tração uniaxial, resistência ao impacto, flamabilidade e análises reológicas do fundido em regime permanente e oscilatório em altas e baixas taxas de cisalhamento. As análises de DRX e de MET indicaram que os híbridos apresentaram estruturas intercaladas (ABS/20A30B/SEBS) e parcialmente esfoliadas (ABS/30B/SBS), essencialmente na fase SAN dos híbridos. As análises por MEV mostraram morfologias distintas da superfície de fratura na tração para os híbridos com SBS e SEBS sendo o SEBS caracterizado por uma fratura dúctil. As análises reológicas dos híbridos mostraram o surgimento de um caráter pseudo-sólido, com aumento significativo nos módulos de armazenamento e na viscosidade complexa, em especial para os híbridos com SBS. Este comportamento revela uma provável dispersão em escala nanométrica das argilas nos híbridos ABS, seja na forma simples ou mistura binária de MMTO. A resistência ao impacto, de todos os híbridos, foi significativamente reduzida devido às micro ou nano partículas de argila que podem atuar como defeitos aumentando aconcentração das tensões localizadas. Melhorias significativas nas propriedades mecânicas de tração quanto ao módulo de elasticidade foram verificadas nos híbridos com SBS em relação ao ABS de referência, por sua vez os híbridos com SEBS mostraram um expressivo comportamento dúctil. No ensaio de flamabilidade na horizontal (norma UL 94 HB) verificou-se uma supressão do gotejamento de material incandescente durante a queima dos híbridos contendo SBS, gotejamento observado nos híbridos com SEBS e no ABS de referência, este comportamento favorável é provavelmente devido à viscosidade do híbrido fundido SBS ser o dobro do SEBS. O estudo da cinética de degradação termo-oxidativa dos híbridos mostrou que a energia de ativação dos híbridos compatibilizados com SEBS é significativamente maior do que os híbridos com SBS, provavelmente devido à hidrogenação do butadieno no SEBS que melhora a sua estabilidade térmica. O grau de dispersão obtido pelas argilas permite designar estes híbridos como nanocompósitos de ABS
Abstract: The present work, shows a study about the relationship between structure and properties of hybrids of organically modified montmorillonites (MMTO) and terpolymer of acrylonitrile-butadiene-styrene (ABS), compatibilized with styrene-ethylene-butadienestyrene (SEBS) or styrene-butadiene-styrene (SBS) prepared by melt blending process. Four formulations of hybrids were proposed in a 22 factorial design of experiments to study the effect of factors compatibilizer (SEBS and SBS) and composition of OMMT (Cloisite 30B and Cloisite 30B + Cloisite 20A mixture (1:1)). The binary mixture of clay was proposed to verify the feasibility of balancing the hydrophobic and hydrophilic character of surfactants these two types of clays. The processing steps were: 1) Preparation of four masterbatches in mass ratio of 49,5: 40: 10:0,5 of ABS/clay/compatibilizer/antioxidant in an internal mixer; 2) Dilution to 4% by weight of OMMT; 3) Extrusion of the compound; 4) Granulation in mill and injection molding of test specimens. The effect of these factors and their interactions were evaluated through analysis of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetry (TGA), differential scanning calorimetry (DSC), uniaxial tensile tests, impact strength, flammability and rheological analysis at high and low shear rates. The analyses of XRD and TEM showed that hybrids had structures intercaled (ABS/20A30B/SEBS) and partially exfoliated (ABS/30B/SBS) essentially in the SAN phase of the hybrids. The analyses by SEM showed different morphologies of the fracture surface in tensile for hybrids with SBS and SEBS, being the SEBS characterized by a ductile fracture. The analyses rheological of hybrids showed the appearance of a pseudo-solid behavior, with a significant increase in storage modulus and complex viscosity, in particular for hybrids with SBS. This behavior reveals a probable dispersion in nano scale of clays in hybrids ABS, either as single or binary mixture of MMTO. The impact strength of all hybrids were significantly reduced due to micro or nano clay particles that can act as defects increasing the concentration of localized stresses. The mechanical properties showed positive results of tensile as so elastic modulus observed in hybrids with SBS in relation to pristine ABS, while hybrids with SEBS showed a significant ductile behavior. In horizontal flammability test (UL 94 HB) verified a suppression of dripping of incandescent material during the burning of hybrids containing SBS, drip observed in hybrids with SEBS and pristine ABS reference, this behavior is probably due to the viscosity of hybrid melted SBS be the double of SEBS. The study of the kinetics of thermo-oxidative degradation of hybrids showed that the activation energy of the hybrid compatibilized with SEBS is significantly greater than the hybrids with SBS, probably due to hydrogenation of the butadiene on SEBS which improves their thermal stability. The degree of dispersion obtained by clays allows to designate these hybrids how nanocomposites ABS
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Ciencia e Tecnologia de Materiais
Mestre em Engenharia Química
Kuerten, Ariane Salvador. "Pré-concentração de carvão mineral da Mina de Moatize com tecnologia Sensor Based Sorting - SBS." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/163429.
Full textThis research is part of a project financed by ITV - Vale Technological Institute, in partnership of UFRGS. Due to coal heterogeneity, particles with low or no content of carbon are mixed with high quality coals and constitute a significant part of the run of mine, which promotes an increase in costs of waste processing and transportation. Commercially available mobile and semi-mobile sorting equipments for mining ores implement dry processes for preconcentration. Therefore, it is estimated that the SBS technique could be used in preconcentration of Mozambique's coal, with the aim to reduce the waste sent to the concentration plant, thus reducing operational costs and environmental impacts. The SBS technique was applied to four different coal's of the Moatize Mine seam and the efficiency was evaluated. The results shows it is possible reduce the ash content in the coarse fraction from feed plant. Through removal of the low quality ore was possible reduce 10 to 14% of mass, which promoted the reduction of ash content from 10 to 20% in coarse fraction feeding the concentration plant.
Gustafsson, Astrid, and Sara Lahti. "Byggnadsrelaterad ohälsa och psykiskt lidande." Thesis, Umeå universitet, Institutionen för psykologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-159511.
Full textBuilding related intolerance (BRI) is a condition with disturbing and unspecified symptoms attributed to certain buildings or parts of buildings. In previous research mental ill-health has been identified as a risk factor for BRI, but the studies investigating this are still few. The general aim of the current study was to investigate how burnout, depression, anxiety and stress, defined as psychological distress, is constituted among people with different levels of severity of BRI. Level of severity was defined in two different ways. As number of BRI-symptoms (distributed into three groups; mucosal, skin and general symptoms) and as intensity ratings of suffering from BRI-symptoms. The data was collected through a questionnaire answered by 106 participants including a control group. Participants were recruited from their occupational health care and their workplace. The participants worked at the university hospital of Umeå or the hospital in Skellefteå. The results showed that there were significantly more people that reached a cut-off for severe burnout (4.47), in the group with severe BRI. The group with severe BRI rated significantly higher than all other groups regarding burnout and significantly higher than a control group regarding depression. All parts of psychological distress had a significant positive correlation with measures of suffering from BRI-symptoms. The results indicates that psychological distress, burnout in particular and partially depression, is associated with increasing severity levels of BRI.
Maciel, Emerson Rodrigues. "O emprego de borracha termoplástica tipo estireno-butadieno-estireno em cimentos asfálticos de petróleo." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266942.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: Este trabalho apresenta resultados o estudo de pesquisa e desenvolvimento de misturas de polímeros em cimento asfáltico de petróleo. O asfalto é um excelente material aglutinante utilizado na construção de rodovias e vias urbanas, entretanto o aumento do número de veículos comerciais e da carga transportada por eixo tem levado a deteriorização prematura dos pavimentos. Os resultados obtidos mostram que o polímero do tipo estireno-butadieno-estireno quando incorporado ao asfalto traz melhoria nas propriedades físico-químicas e desempenho, sobretudo quando em contato com cargas pesadas, em climas quentes, tornando-o resistente à deformação permanente, pela preservação de sua flexibilidade e elasticidade. A incorporação de 4% polímero tipo estirenobutadieno-estireno ao asfalto resultou na melhoria de suas propriedades, principalmente a resistência ao envelhecimento, aumento no ponto de amolecimento, ganho de recuperação elástica. O asfalto modificado é uma boa solução, pois embora aumente os custos iniciais do produto, resulta em um ótimo custo benefício, reduzindo a necessidade de manutenção das rodovias ou vias urbanas ao longo dos anos
Abstract: This paper presents laboratorial research results comprising developing project of polymer mixtures in petroleum asphalt cement. The asphalt is an excellent binding material used in the highway constructions and unban roads, however the increase of the commercial vehicles number and the load transported by axle have led to the premature pavements failure. The laboratory outcomes obtained show that the SBS polymer, which is embedded to the asphalt, brings improvement in the physico - chemical properties and performance mainly for its good performance under heavy loads in hot climates becoming resistant to the permanent deformation, but maintaining the flexibility as the asphaltic concrete providing elasticity. The SBS polymer is a good solution, although it increases the initial costs of the product, however with a great costeffective regarding the maintenance of the highways or unban roads over the years
Mestrado
Ciencia e Tecnologia de Materiais
Mestre em Engenharia Química
Moreira, AntÃnio AurÃlio Gomes. "Propriedades ReolÃgicas e ResistÃncia a OxidaÃÃo de Cimento AsfÃltico de PetrÃleo (CAP) Modificado com Cardanol." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=12145.
Full textNeste trabalho, um derivado fenÃlico extraÃdo do lÃquido da casca da castanha de caju (LCC), fonte natural e renovÃvel, foi utilizado como aditivo modificador de cimento asfÃltico de petrÃleo (CAP). FraÃÃes extraÃdas por diferentes mÃtodos (I, II e III) foram analisadas por cromatografia lÃquida de alta eficiÃncia (HPLC) e por espectroscopia no infravermelho, tendo sido identificadas como cardanol. Os CAP modificados por cardanol (I) foram comparados ao CAP modificado por LCC e estireno-butadieno-estireno (SBS), sendo avaliadas suas propriedades reolÃgicas antes e apÃs envelhecimento simulado. O LCC e o cardanol (I) atuaram de forma semelhante, aumentando os valores de penetraÃÃo e reduzindo o ponto de amolecimento, a viscosidade, a temperatura de usinagem e compactaÃÃo (TUC), e a susceptibilidade tÃrmica do ligante. Os parÃmetros reolÃgicos, obtidos em reÃmetro de cisalhamento dinÃmico (DSR), indicaram que LCC e cardanol (I) tornaram o CAP mais susceptÃvel à deformaÃÃo permanente, no entanto, nÃo houve alteraÃÃo do desempenho do CAP a baixas temperaturas. Foi verificado que o cardanol pode atuar como agente compatibilizante de CAP modificado com SBS, tal como os Ãleos aromÃticos comerciais. Em relaÃÃo ao CAP original, o CAP com SBS apresentou diminuiÃÃo na penetraÃÃo e na susceptibilidade tÃrmica, e aumento do ponto de amolecimento e da viscosidade. Os parÃmetros reolÃgicos (G*, δ) indicaram que o CAP com SBS foi mais resistente à deformaÃÃo permanente. O efeito dos aditivos em relaÃÃo ao grau de desempenho (PG), a altas temperaturas, para os CAP modificados foi CAP/SBS > CAP/cardanol ≥ CAP/LCC. O PG, a baixas temperaturas, foi superior para CAP/SBS, indicando que este pode ser aplicado em regiÃes de clima frio. A resistÃncia à decomposiÃÃo tÃrmica, observada por termogravimetria (TGA), foi semelhante para todas as amostras. As curvas de calorimetria exploratÃria diferencial (DSC) mostraram que todas as amostras possuem baixo teor de fraÃÃes cristalizÃveis e que o CAP modificado com cardanol apresenta maior resistÃncia ao trincamento tÃrmico. O efeito de cardanol como potencial antioxidante foi avaliado apÃs o envelhecimento em estufa RTFOT, e por espectroscopia no infravermelho (FTIR). Os resultados indicaram que o cardanol foi Ãtil para atuar como aditivo redutor do envelhecimento do CAP. Na preparaÃÃo de corpos de prova de misturas CAP/cardanol e agregado constatou-se uma economia no teor de ligante requerido, comparando-se com o CAP sem aditivo. No ensaio Lottman modificado, foi verificado que o cardanol agiu como melhorador da adesividade (AMA) entre ligante e agregado, conforme medida da resistÃncia à traÃÃo (RRT) acima de 80%, e acima do valor encontrado para o CAP virgem.
In this work, phenolics from renewable and natural sources extracted from cashew nut shell liquid (CNSL) were used as petroleum asphalt cement (PAC) modifiers additives. Fractions extracted by different methods (I, II and III) were analyzed by High Performance Liquid chromatography (HPLC) and Infrared Spectroscopy (FTIR) and were identified as cardanol. The PAC modified by cardanol I was compared to PAC modified with CNSL and styrene-butadiene-estyrene (SBS) by measuring its rheological properties before and after an aging simulation evaluation. CNSL and cardanol I showed, similarly, increasing values of penetration and decreasing the soft point, the viscosity, the mixing and compaction temperature and the thermal susceptibility. Regarding the rheological parameters obtained by dynamic shear rheometer (DSR), it was observed that PAC/CNSL and PAC/cardanol became more susceptible to rutting. It was verified that cardanol acted as a compatibility agent in PAC modified with SBS in a similar way as for commercial aromatics oils. On the other hand, PAC modified with SBS showed decreasing on penetration values and on thermal susceptibility, as well as increasing soft point and viscosity values. PAC modified with SBS was more resistant to rutting as observed by its rheological parameters (G*, δ). The performance grade (PG) in high temperatures was lower for PAC/cardanol I and PAC/CNSL then for PAC modified with SBS, confirming the conclusions obtained by analysis of the rheological parameters. The PG value, in low temperatures, was greater for PAC modified with SBS then those for the other modified PAC, indicating that this mixture can be used in cold climates. For PAC modified with cardanol I and with CNSL, there was no change performance in low temperatures. The resistance to thermal degradation verified by thermogravimetry (TGA) was similar for all samples. The differential scanning calorimetry (DSC) showed that all samples have low content of crystallizable fractions and PAC modified by cardanol has a higher thermal crack resistance. Simulated oxidative ageing showed that cardanol acted as antioxidants. For the dosage of PAC modified with cardanol II, it was observed an economy in the content of used binder compared to PAC without any additive. In the Lottman modified test it was verified that cardanol II acted as an anti-stripping agent (ASA) between the binder and aggregates because it was found a tensile strength ratio (TSR) higher than 80% and larger than the value found for unmodified PAC.
Engvall, Karin. "A Sociological Approach to Indoor Environment in Dwellings : Risk factors for Sick Building Syndrome (SBS) and Discomfort." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3506.
Full textAnitelli, Andre. "Estudo do dano por umidade de misturas densas com ligantes asfálticos convencional e modificado com polímero SBS." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18143/tde-17102013-100748/.
Full textThis research presents a contribution to understanding hot mix asphalt (HMA) moisture damage susceptibility according to ASTM D 4867 and AASHTO T 283 tests. A full factorial experiment design was carried out considering the factor variations, on two levels: asphalt type (CAP 50/70 and CAP 50/70+SBS), additive presence (with or without hydrated lime) and mixture procedure (short and long term aging). The experimental program resulted in 8 types of asphalt mixes (experimental conditions) which were characterized by the original properties and after a thermal conditioning wich consisted of a freezing phase (-18 °C for 16 hours) and a thawing phase (60 °C for 24 hours). Findings indicate that (i) no one mix was considered susceptible to moisture damage, however the ITR (indirect tensile ratio) of the CAP 50/70 mixes resulted ITR near to protocol admissible values; (ii) in general, CAP 50/70+SBS mixes presented higher resilient modulus, indirect tensile strength and indirect tensile ratio values, (iii) the addition of hydrated lime did not show remarkable changes in original properties, nevertheless it contributed for maintaining or increasing the moisture damage resistance; (iv) short and long term aging procedures (ASTM and AASHTO) did not cause important changes in original properties and after conditioning the mixes showed similar behavior tendencies.
Cordella, Cristina Dias. "Funcionalização do copolímero em bloco estireno-butadieno-estireno (SBS) e sua utilização em misturas com nylon 6." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2000. http://hdl.handle.net/10183/40422.
Full textIn this work chemical modification of styrene-butadiene-styrene copolymer with glycidyl methacrylate was carried out in an internal mixer through radical reactions. Dicumyl peroxide was used as initiator. Grafting reactions with maleic anhydride were also performed. During reactions torque was monitored continuously. Reactions products were characterized by Fourier transform infrared spectroscopy and crosslinking was evaluated in terms of the insoluble fraction in toluene. A factorial design was performed to evaluate the effects of the glycidyl methacrylate, Dicumyl peroxide content and time on the grafting degree, conversion and final torque. Only principal effects were significant to grafting degree, conversion and final torque. The glycidyl methacrylate content had a significant effect on final torque while time had a significant effect on conversion. Dicumyl peroxide content was found to be the most significant factor for final torque and conversion and had small effect on grafting degree. The modified elastomers were used as compatibilizing agents and impact modifiers for blends with nylon 6. The morphologic analysis showed that the grafting reaction causes interaction between nylon and elastomer. On the mixing conditions used in this work, the grafted SBS was not efficient as impact modifier. The toughness of the blends was smaller than the values corresponding to pure nylon, although toughness of blends with grafted SBS was a little higher than toughness of blends with unmodified SBS.
Rodrigues, Fabíola Odete. "Efeito do líquido da Castanha do Caju (LCC) nas propriedades reológicas do ligante asfáltico modificado por SBS." reponame:Repositório Institucional da UFC, 2010. http://www.repositorio.ufc.br/handle/riufc/581.
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The objective of this study was to modify the asphalt binder (LA) with 50/70 penetration by incorporating SBS (3, 4 and 4.5%) and the cashew nut shell liquid (CNSL) (1% w/w). The studies were directed towards assessing and analyzing the rheological master curves obtained from tests on a dynamic-shear rheometer (DSR). In addition, we assessed the effects of additives in relation to the viscosity, storage stability, and oxidative aging simulated at the RTFOT. The results indicated that the addition of SBS increases the stiffness and the elastic response of the binder at high temperatures. The master curves showed improvements in the rheological parameters at intermediate and high temperatures, where the process of permanent deformation occurs. Samples with SBS contents 3, 4 and 4.5% were tested for storage stability for 48 hours. The sample with 3% SBS showed no phase separation when stored under the conditions investigated, however, samples with 4 and 4.5% of SBS showed phase separation. In these samples (4 and 4.5%), the addition of CNSL embedded in the modified binder by SBS show the potential to estabilize the binder-polymer mixture, avoiding phase separation. The CNSL, therefore, proved to be potentially useful to prevent phase separation of the LAs with the polymer. The results also indicate that the presence of CNSL promoted a reduction in viscosity and flow activation energy of the binder modified by SBS, contributing thus to improve the thermal susceptibility of the modified binder. Tests of resilient modulus (MR) and tensile strength (RT) in asphalt mixtures containing modified binder suggest that the presence of SBS makes the mixture less susceptible to deformation and failure than mixtures with pure LA. However, the asphalt mixture containing the binder modified by SBS with the addition of CNSL presents an even greater hardening when compared to the SBS blend containing no additive. It is likely that the presence of polymerized CNSL has contributed to the hardening of the sample.
O objetivo deste trabalho foi modificar o ligante asfáltico (LA) com penetração 50/70 pela incorporação de SBS (3, 4 e 4,5% m/m) e do líquido da castanha do caju (LCC) (1% m/m). Os estudos foram dirigidos para avaliação dos parâmetros reológicos e análise das curvas mestras obtidas através de ensaios realizados em um reômetro de cisalhamento dinâminco (DSR). Além disso, foram avaliados os efeitos da presença dos aditivos em relação à viscosidade, estabilidade à estocagem e envelhecimento oxidativo simulado em estufa RTFOT. Os resultados indicaram que a adição de SBS aumenta a rigidez e a resposta elástica do ligante em altas temperaturas. As curvas mestras mostraram melhorias nos parâmetros reológicos em temperaturas intermediárias e altas, onde ocorre o processo de deformação permanente. As amostras com teores de 3, 4 e 4,5% foram testadas quanto à estabilidade a estocagem por 48h. A amostra com teor de 3% SBS não apresentou separação de fases quando estocada nas condições trabalhadas, no entanto, as amostras com teores de 4 e 4,5% apresentaram separação de fases. Nessas amostras (4 e 4,5%), a adição do LCC incorporado ao ligante modificado por SBS demonstrou estabilizar a mistura ligante-polímero, evitando a separação de fases. O LCC, portanto, mostrou-se potencialmente útil para prevenir a separação de fases dos LAs modificados com o polímero. Os resultados também indicam que a presença do LCC promoveu uma redução na viscosidade e na energia de ativação de fluxo do ligante modificado por SBS, contribuindo, portanto, para melhorar a susceptibilidade térmica do ligante modificado. Os ensaios de módulo de resiliência (MR) e reistência a tração (RT) nas misturas asfálticas contendo os ligantes modificados sugerem que a presença do SBS torna a mistura menos susceptível à deformação do que as misturas com o LA puro. No entanto, a mistura asfáltica contendo o ligante modificado por SBS com adição de LCC apresenta um endurecimento ainda maior quando comparada a mistura que contém o SBS sem o aditivo. É provável que a presença de LCC polimerizado tenha contribuído para o endurecimento da amostra.
Slavinskis, Nerijus. "Trumpų impulsų kokybės moduliacijos išilgai diodais kaupinami kietojo kūno minilazeriai: generavimas, charakterizavimas ir panaudojimas." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110630_134132-74098.
Full textThe dissertation is dedicated to the detailed numerical modelling of generation dynamics of actively and/or passively Q-switched diode laser longitudinally pumped solid-state lasers, characterization of spatial and temporal laser properties and for the demonstration of application possibility of created minilasers. A detailed theoretical model for the description of generation dynamics using travelling wave approach is presented. In this model more parameters of active laser medium, pump sources and resonator architecture are taken into account. In this thesis the results which show the principal difference between results obtained using the laser travelling wave model and point laser model are presented. Using point laser model the problems of generated pulse timing jitter in passively Q-switched lasers are described and its lowering possibilities using different pumping methods are suggested. In this thesis new, based by the second order moment, laser beam characterisation by knife-edge method is presented. Also laser pulse compression possibilities in tetrachloride CCL4 medium are described. It is showed that using seed signal it is possible to obtain shorter (< 60 ps) and more stable optical pulses. In this thesis application possibilities of created minilasers are presented: the experimental results of the Z-scan measurements obtained using pulses with different pulse shapes for fused silica are presented; also experiments, in which, created minilasers for paper cleaning... [to full text]
Dhondt, Axel. "Impacts du procédé de fabrication sur les propriétés thermorhéologiques de liants routiers purs et modifiés aux polymères." Electronic Thesis or Diss., Ecole nationale supérieure Mines-Télécom Lille Douai, 2018. http://www.theses.fr/2018MTLD0010.
Full textSobreiro, Fernanda Pilati. "Efeito da adição de ácidos fosfóricos no comportamento reológico de ligantes asfálticos puros e modificados com copolímero SBS." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18143/tde-28052014-100359/.
Full textThe addition of modifiers in asphalt binder to improve its behavior is a common practice nowadays. There are many types of modifiers, among them the most used in the Brazilian federal highways is the SBS copolymer. In addition to polymers, polyphosphoric acid (PPA) is another type of modifier that produces good characteristics when added to asphalt binder. Despite the positive effects, it is known that this material is imported, which makes its purchase as well as the final product very expensive. Considering the opportunity to work with a product with the same basic component, but of national origin, which would make it the most affordable modifier, the present study decided to verify the behavior of the addition of phosphoric acid (PA85) to the asphalt binder. Therefore, the purpose of this thesis is to analyze the effect of the addition of phosphoric acid to the rheological behavior of pure and modified asphalt binders with the SBS copolymer. For both, empirical and rheological tests were conducted in order to verify the behavior of these materials/substances. In the first part of the research, two asphalt binders base CAP50/70 asphalt binder graded PG64-XX (Replan and Lubnor) were modified only with the addition of the two acids (PPA and PA85), while in the second part of these asphalt binders base were modified with SBS copolymer with or without the presence of acids. The tests evaluated penetration, softening point, rotational viscosity, multiple stress creep and recovery (MSCR), LAS modified, and storage stability. In general, the addition of the modifiers enhances the behavior of the asphalt binders, for they improve recovery, are less susceptible to rutting and are more resistant to fatigue. It was found that the type of asphalt binder base directly influences the behavior of materials, regardless of added modifiers. The addition of modifiers was greater in the asphalt binder from the Replan. Compared to acids, it is concluded that the addition of PA85 was satisfactory, since the performance was similar to the PPA acid behavior, but with slightly less significant effect. The addition of acid improved the storage stability of the modified asphalt binders, and it was found that the addition of such modifiers allows reducing the content of the SBS copolymer. Regarding the ability to support traffic, the addition of high levels of these modifiers is not feasible because they show similar support for modified asphalt binders with low and intermediate levels.
Veronese, Vinicius Bassanesi. "Desenvolvimento e avaliação de propriedades de misturas de poliestireno (PS) e copolímeros em bloco estireno-butadieno-estireno (SBS)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2003. http://hdl.handle.net/10183/4609.
Full textSilva, Patrícia Alves da. "Nanocompósitos de borrachas termoplásticas do tipo poli(estireno-b-butadieno-b-estireno) - SBS e poli(etireno-butadieno) - SSBR." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2007. http://hdl.handle.net/10183/10994.
Full textSBS and SSBR nanocomposites were obtained with organically modified montmorillonites. Different methods of obtaining the SBS nanocomposite were employed, and all aimed the improvement of the mechanical properties of pure rubber by adding MMT. PBLH (hydroxylated liquid polybutadiene), epoxidized SBS and PBLH (hydroxylated liquid polybutadiene) were used as compatibilizer between the clay and the thermoplastic rubber. The nanocomposites were obtained in the mixture chamber. Most of these nanocomposites showed improvement in their properties when epoxidized SBS and clay were used. The nanocomposites from a rubber solution obtained using lower agitation speed presented higher values of modulus without losing elongation and tension. The best results were those using the MMT 10 A and epoxidized SBS as compatibilizer. The SSBR nanocomposites, also in all cases, showed improvement in their properties when clay and epoxidized rubber were used. The addition of MMT and the use of epoxidized rubbers as compatibilizer increased the properties of the nanocomposites when compared with pure rubber, which means that the compatibilizer increased the interaction between the clay and the rubber matrix. This effect is stronger when MMT 10 A was used, and it can be verified in the mechanical properties, TEM and DMA analysis.The effect of these nanocomposites as impact modifier in a polypropylene matrix was also evaluated in the present work. The blends with the SBS nanocomposites also had positive results, and the impact resistance test showed to be three-fold higher than for the pure PP.
Wang, Chengju. "Energy use and energy saving in buildings and asthma, allergy and sick building syndrome (SBS): a literature review." Thesis, Högskolan i Gävle, Energisystem och byggnadsteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-30086.
Full textPodkalicka, Aneta Monika. "Lost in translation? Language policy, media and community in the EU and Australia : some lessons from the SBS." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16696/1/Aneta_Podkalicka_Thesis.pdf.
Full textPodkalicka, Aneta Monika. "Lost in translation? Language policy, media and community in the EU and Australia : some lessons from the SBS." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16696/.
Full textEdvardsson, Berit. ""Det är inte mig det är fel på, det är huset" : en studie av prognosfaktorer och bemötande med fokus på sjuka hus-syndromet." Doctoral thesis, Umeå universitet, Epidemiologi och global hälsa, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-111269.
Full textBackground: Sick Building Syndrome (SBS) is still in 2015 a controversial condition. The set of non-specific symptoms occurring in a particular building and not caused by specific illness such as allergy or infection are questioned. The variousSBS symptoms can be grouped as dermal, mucosal and general and there is no universally accepted clinical definition of SBS. Symptoms normally improve or disappear when people are not exposed in a particular building. SBS is a multifactorial disease and described as a syndrome caused or aggravated by many factors related to indoor environment such as dampness and mould, insufficiency of fresh air, but also psychosocial and individual factors like female gender and personality. Objectives: The hypothesis is that personal factors such as previous health, actions taken, time, treatment, personality and coping resources are factors important in influencing the prognosis for SBS patients. The main purpose of this thesis is to explore more about how the symptoms affect work-capability and if SBS patients recover from their symptoms. Another important aim is to explore the experience of the emergence of symptoms and encounters in a group of people with SBS. To find out more about personality and coping resources and their importance for the progress of SBS symptoms comparisons were made with a selection from the general population, a group of patients having hand eczema and a group of patients with perceived sensitivity to electricity. Methods: A follow-up questionnaire focusing on current medical and social status, care, treatment, other measures taken, coping and personality traits was sent to 239 patients with non-specific building-related symptoms, assessed during the period between 1986-1998 at the University Hospital in Umeå, Sweden, response rate 79,1%. Prognosis and risk factors for prognosis were calculated for the SBS patients. Measurement of personality traits like self-image was done using Structural analysis of Social Behaviour, SASB, and coping ability was measured with Coping Resources Inventory, CRI. Similar follow-up questionnaires for patient groups with hand eczema and perceived electrical sensitivity were used and response rates were 68% respectively 73%. Risk factors for prognosis with focus on self-image and coping were calculated for the SBS patients and the group of patients having hand eczema. Comparisons were made between self-image and coping among SBS patients, patients with electrical hypersensitivity, patients with hand eczema and a selection from the general population. To explore the experience of SBS symptoms and encounters a semi-structured interview was performed with 10 informants with symptoms of SBS. Five of them were previously diagnosed and had participated in the earlier follow-up study. The remaining five had had SBS symptoms for a shorter period. The interviews were analysed using qualitative content analysis. Results: The degree and severity of SBS symptoms decreased over time, although nearly half of the SBS patients claimed that symptoms were more or less unchanged after 7 years or more. The risk of having no work capabilities was significantly increased at follow-up if the time from debut to first visit at the hospital clinic was more than one year and this risk was also significantly higher if the patient at the first visit had 5 or more symptoms. Common daily activities, like going by bus, also aggravated the SBS symptoms according to answers in the questionnaires. The informants’ experiences of the emerging SBS symptoms are that when they first appear they are often similar to those of flu like runny nose and eyes, hoarseness, cough, and headache. Many of the informants act to change the way they manage the situation as a result of increased symptoms. During this whole process the informants/patients perceived a lack of confirmation and support from e.g. employers, primary health care and occupational health care centres. Regarding self-image, all three patient groups scored higher on spontaneous and positive self-image than a comparison group. They were all less controlled. The patients with hand-eczema together with the patients with perceived electrical sensitivity also had a high score on negative self-image. CRI- domains did not differ between patients and comparison group except on CRI cognitive, were the hand eczema patients had a lower score than the comparison group contrary to SBS patients who had a higher score than the comparison group. The patients with perceived electrical sensitivity had a higher score on CRI spiritual. Self-image or coping ability was not associated with SBS symptoms or persistent hand eczema symptoms at follow-up and their personality did not affect their work capability. Previous atopic dermatitis was the only consistent predictor of hand eczema at follow-up. Conclusion: Within this group of SBS patients there are long lasting symptoms aggravated by environmental factors. The results support that early and comprehensive measures for rehabilitation are essential for these patients. In the beginning the symptoms of SBS are diffuse and difficult to recognise for all involved. Patients with SBS symptoms experience a lack of confirmation and support. It is important that healthcare personnel confirm the patient and are aware of the possible connection between symptoms and the indoor environment. For employers and facility managers knowledge of their obligations in terms of working environment is important. Differences in personality traits were seen in a well-established condition and not only in patients with medically unexplained symptoms. This can imply that patients with general chronic symptoms can deviate from the general population with respect to self-image and coping ability. Certain personality traits may be potential risk factors that increase the probability of encountering and experiencing stressful work situations.
Rodrigues, FabÃola Odete. "Effect of the cashew nut shell liquid (CNSL) on the rheological properties of the asphalt binder modified with SBS." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5691.
Full textO objetivo deste trabalho foi modificar o ligante asfÃltico (LA) com penetraÃÃo 50/70 pela incorporaÃÃo de SBS (3, 4 e 4,5% m/m) e do lÃquido da castanha do caju (LCC) (1% m/m). Os estudos foram dirigidos para avaliaÃÃo dos parÃmetros reolÃgicos e anÃlise das curvas mestras obtidas atravÃs de ensaios realizados em um reÃmetro de cisalhamento dinÃminco (DSR). AlÃm disso, foram avaliados os efeitos da presenÃa dos aditivos em relaÃÃo à viscosidade, estabilidade à estocagem e envelhecimento oxidativo simulado em estufa RTFOT. Os resultados indicaram que a adiÃÃo de SBS aumenta a rigidez e a resposta elÃstica do ligante em altas temperaturas. As curvas mestras mostraram melhorias nos parÃmetros reolÃgicos em temperaturas intermediÃrias e altas, onde ocorre o processo de deformaÃÃo permanente. As amostras com teores de 3, 4 e 4,5% foram testadas quanto à estabilidade a estocagem por 48h. A amostra com teor de 3% SBS nÃo apresentou separaÃÃo de fases quando estocada nas condiÃÃes trabalhadas, no entanto, as amostras com teores de 4 e 4,5% apresentaram separaÃÃo de fases. Nessas amostras (4 e 4,5%), a adiÃÃo do LCC incorporado ao ligante modificado por SBS demonstrou estabilizar a mistura ligante-polÃmero, evitando a separaÃÃo de fases. O LCC, portanto, mostrou-se potencialmente Ãtil para prevenir a separaÃÃo de fases dos LAs modificados com o polÃmero. Os resultados tambÃm indicam que a presenÃa do LCC promoveu uma reduÃÃo na viscosidade e na energia de ativaÃÃo de fluxo do ligante modificado por SBS, contribuindo, portanto, para melhorar a susceptibilidade tÃrmica do ligante modificado. Os ensaios de mÃdulo de resiliÃncia (MR) e reistÃncia a traÃÃo (RT) nas misturas asfÃlticas contendo os ligantes modificados sugerem que a presenÃa do SBS torna a mistura menos susceptÃvel à deformaÃÃo do que as misturas com o LA puro. No entanto, a mistura asfÃltica contendo o ligante modificado por SBS com adiÃÃo de LCC apresenta um endurecimento ainda maior quando comparada a mistura que contÃm o SBS sem o aditivo. à provÃvel que a presenÃa de LCC polimerizado tenha contribuÃdo para o endurecimento da amostra.
Lebre, Inês Navarro Soeiro Guedes. "Eficácia dos diluidores do kit SBS CryosSystem e do BotuCrio na criopreservação de sémen em garanhões Puro Sangue Lusitano." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2022. http://hdl.handle.net/10400.5/23560.
Full textFoi também avaliado o efeito da adição de cushion fluid previamente à centrifugação. Houve uma redução significativa (p<0,0001) da motilidade média do sémen fresco (71%) para o sémen congelado (36%), e dos parâmetros de velocidade VCL, VSL e VAP entre estes dois períodos (p<0,0001). Observou-se um efeito significativo (p<0,0001) dos fatores “garanhão” e “diluidor” sobre as variáveis estudadas, não havendo uma interação significativa entre estes dois fatores. O BotuCrio foi o diluidor que apresentou uma motilidade média após descongelação mais elevada (48%) e o Azul foi o que apresentou uma menor motilidade média (21%). Quanto à vitalidade, o diluidor Vermelho obteve a maior média (41%) e o diluidor Laranja a média mais baixa (34%). Em relação ao HOST, o diluidor Violeta apresentou a maior média de caudas enroladas (47%), enquanto o BotuCrio apresentou a menor média (35%). A motilidade apresentou uma correlação forte com o VCL (0,82) e VAP (0,77), uma correlação moderada com o VSL (0,56) e vitalidade (0,63), e não apresentou correlação com o HOST (-0,01). A adição de cushion fluid apresentou um efeito significativo sobre as variáveis motilidade (p<0,005), vitalidade (p<0,0005) e HOST (p<0,05). Observou-se a existência de variabilidade entre garanhões nos diversos parâmetros avaliados, mais evidenciada na motilidade, e dentro do mesmo garanhão, entre diferentes ejaculados, sendo a amplitude desta variabilidade diferente consoante o garanhão avaliado. Assim, neste trabalho não foi possível determinar a existência de um diluidor específico para cada garanhão que permitisse a otimização do processo de criopreservação.
ABSTRACT - The optimization of semen cryopreservation protocols is essential to improve its viability and, consequently, fertility rates. The present master's dissertation consisted in the study of the effectiveness of the freezing extenders that are part of the SBSCryoSystem Kit – Red, Green, Orange, Purple and Blue - and BotuCrio in six purebred Alter Real Lusitano stallions. The sample used was of 6 stallions and 5-6 collections were performed per stallion in a total of 204 straws. The main objectives of the present study were to evaluate the effect of the different extenders on several seminal evaluation parameters as well and the existence of inter and intraindividual variability. Seminal parameters evaluated included a subjective analysis of motility, an objective analysis of sperm kinetics that was performed using the CASA system, the assessment of vitality and the evaluation of membrane integrity and functionality by performing a hypoosmotic test (HOST). The effect of adding cushion fluid prior to centrifugation was also evaluated. There was a significant reduction (p<0,0001) in the mean motility of frozen semen (36%) when compared to fresh semen (71%), associated with a significant decrease (p<0,0001) in VCL, VSL and VAP speed parameters between these two periods. There was a significant effect (p<0.0001) of the “stallion” and “extender” factors on the studied variables but there wasn’t a significant interaction between these two factors. BotuCrio was the extender with the highest average motility after thawing (48%) and the Blue extender was the one with the lowest average motility (21%). As for the vitality, the Red extender presented the highest mean value (41%) while the Orange extender presented the lowest (34%). Regarding the hypoosmotic test, the Violet extender had a higher average of curled tails (47%), while BotuCrio had the lowest average value (35%). Motility showed a strong correlation with VCL (0.82) and VAP (0.77), a moderate correlation with VSL (0.56) and vitality (0.63), and did not show any correlation with the hypo-osmotic test (-0.01). The addition of cushion fluid had a significant effect on the variables motility (p<0,005), vitality (p<0,0005) and HOST (p<0,05). There was variability between stallions in the different parameters evaluated, more evident in motility, and within the same stallion, between different ejaculates, the amplitude of this variability being different depending on the stallion evaluated. Thus, in this work, it was not possible to determine the existence of a specific extender for each stallion that allowed the optimization of the cryopreservation process
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Silva, Patrícia Alves da. "Nanocompósitios de borrachas termoplásticas do tipo poli(estireno-b-butadieno-b-estireno)-SBS e sua aplicação em blendas poliméricas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/97870.
Full textIn this work nanocomposites with organically modified montmorillonite SBS were obtained. Epoxidized SBS was used as compatibilizer, with two different percentages of epoxidation, with the aim of improving their mechanical properties compared to the pure rubber. The nanocomposites were prepared in the mixing chamber. Many of these nanocomposites showed improvement in their properties with the addition of clay and SBS epoxidized. The nanocomposites were obtained containing SBS with lower degree of epoxidation showed higher drying module, without lower losing in stretching and maximum tension. Most of the mixtures containing clay and epoxided SBS caused a gain in the secant modulus. The epoxidized rubber acted as compatibilizer to improve the properties of the nanocomposites. The addition of clay and the use of compatibilizer increases the strength of the interaction between the clay and the rubber matrix. The results The use of MMT 10 and the compatibilizer with lower epoxidation degree presented the best results on the mechanical properties and DMA analysis. The morphology was observed by TEM and AMF. To complete the work, the SBS nanocomposites obtained in industrial plant were used in blends of polypropylene to verify their influence as impact modifiers. It was used PP-g-MA as compatibilizer. The blends showed no gain in mechanical properties probably due to the poor dispersion of clay in the nanocomposite and the poor effect of the aompatibilizer between PP and nanocomposite phases of SBS. The use of PP-g-MA increased the flexural modulus and impact resistance, but their results were lower than those of the blends PP / SBS. The increase in the size of the rubber domains with the presence of compatibilizer proved more effective to aborb the impact.
Slavinskis, Nerijus. "Short pulse q-switched longitudinally diode pumped solid state minilasers: generation, characterization and application." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110630_134119-87467.
Full textDisertacija skirta diodais kaupinamų kietojo kūno lazerių su aktyviąja ir pasyviąja kokybės moduliacija generacijos dinamikos detalesnei skaitmeninei analizei, lazerio impulsų laikinių ir erdvinių parametrų charakterizavimui ir sukurtų minilazerių panaudojimo galimybių demonstracijai. Generacijos dinamikos detalesniai skaitmeniniai analizei, darbe pristatomas sukurtas bėgančiųjų bangų modelis, kuriame atsižvelgiama ne tik į daugelį procesų vykstančių lazerio aktyviajame elemente, bet ir į rezonatoriaus konfigūraciją bei kaupinimo šaltino parametrus. Pateikiami skaitinio modeliavimo rezultatai demonstruojantys šio modelio privalumus lyginant su dažniausiai naudojamu taškiniu lazerio modeliu. Naudojant taškinį lazerio modelį yra nagrinėjama generuojamų impulsų laikinio tirtėjimo problema pasyvios kokybės moduliacijos lazeriuose ir pasiūlyti mažinimo būdai naudojant skirtingus kaupinimo būdus. Darbe taip pat pateiktas naujas, antraisiais momentais pagrįstas, pluošto charakterizavimo judančiu peiliu metodas. Nagrinėjamos lazerių impulsų spūdos galimybės tetrachlorido CCL4 skystyje ir pademonstruota, kad naudojant užkrato signalą galima gauti trumpesnius (< 60 ps) ir stabilesnius optinius impulsus. Darbe pademonstruotos sukurtų minilazerių pritaikymo galimybės: aprašomas netiesinio lūžio rodiklio kvarciniame stikle matavimas Z-skenavimo metodu ir gautų duomenų apdorojimo procedūra įskaitant naudojamų impulsų erdvinę ir laikinę formą; aprašomi eksperimentai, kuriuose sukurti... [toliau žr. visą tekstą]
Senate, University of Arizona Faculty. "Faculty Senate Minutes December 5, 2011." University of Arizona Faculty Senate (Tucson, AZ), 2011. http://hdl.handle.net/10150/209889.
Full textGoll, Maiara Fernanda Gonçalves Holz 1987, Lorena Benathar Ballod 1959 Tavares, Atilano Antonio 1964 Vegini, and Universidade Regional de Blumenau Programa de Pós-Graduação em Engenharia Ambiental. "Estudo da caracterização e dimensionamento de uma unidade de produção de pellets de aparas de papel cartão SBS com PET." reponame:Biblioteca Digital de Teses e Dissertações FURB, 2016. http://www.bc.furb.br/docs/DS/2016/361015_1_1.pdf.
Full textCo-orientador: Atilano Antonio Vegini.
Dissertação (Mestrado em Engenharia Ambiental) - Programa de Pós-Graduação em Engenharia Ambiental, Centro de Ciências Tecnológicas, Universidade Regional de Blumenau, Blumenau.