The UV-Visible spectra of a-C composites and nano composites have provided a very useful information about the electronic states and band structure. The UV-Visible spectra of a-C as well as nanoparticle are qualitatively similar. They do not show any absorption cutoff in wavelength (_max). In fact they are good absorbers of UV-Visible light in whole range. Composites show some absorptions which could be the combined effect of filler as we as host matrix. Since there is no _max, hence it is very unlikely to define any optical band gap. The nanoparticle is a good absorber in midinfrared compared to a-C. That may be due to presence of complicated kind of vibrational modes of carbon cased nanoparticle.Besides Fe3C also produces some additional modes. With kind of spectrum we have it is difficult to identify the different modes unambiguously for nanoparticle. The combined effects of filler as well as host polymer are reflected in both sets of composites. A new absorption is observed in a-C as well as in nanoparticle composites at 2370 cm−1 and 3462 cm−1 respectively. This peak may arise in composites due to interaction between filler and host matrix. The thermo gravimetric analysis is a useful characterization techniques for polymer and composites. It gives the information about the stability, phase change, degradation, chemical reaction and many more. The a-C composites as well as nano composites are stable up to 200_ C. These composites can be safely used for any practical purpose below this temperature. During the synthesis of composites the filler does not take part in any reaction. This fact is reflected in the DTG curve. The composites degrade in the way host polymer degrades.

published_or_final_version / Chemistry / Master / Master of Philosophy

In the spring of 1998, a closed end gravity flow pipeline was installed in the Lethbridge Northern Irrigation District. The pipes ranged from 900 mm to 300 mm in diameter. / Manholes were placed at several locations along the pipeline and were used to install velocity meters and pressure transducers, which recorded data every second. Pressures and velocities during periods of steady state were used to calculate the head loss, Re and the Hazen-Williams friction factor, "C", along lengths of constant diameter. / The results were compared to the industry design standard of C = 150 (used for the design of rigid PVC pipe installations) and to the theoretical hydraulically smooth line developed from the Moody diagram and the Darcy-Weisbach equation. Since the maximum and minimum calculated values of C came in the 750 mm and 900 mm diameter pipes, respectively, and all other C values, including those from the 300 mm and 650 mm diameters, fell between these, pipe diameter was assumed not to be a variable. Therefore all the field data was averaged. The average value of Re for the range studied was 9.73 x 105 . The corresponding best-fit C value is 147.7, which is 6.0% lower than the derived theoretical maximum. Since the derived theoretical maximum is the ideal condition and the recorded data was slightly lower and therefore determined be a good representation of what can be expected in true field conditions.

Green chemistry principles served as a guide for three industrially-relevant projects. In the first project, silylamines were applied as reversible ionic liquids for carbon dioxide capture from post-combustion flue gas streams. The effect of silylamine structure was thoroughly researched to develop a comprehensive library of silylamines and an accompanying set of structure-property relationships. The proposed solvent systems have the potential to present significant energy savings, as design has focused on their use in a non-aqueous, solvent-free environment. The second project also dealt extensively with carbon dioxide capture, as a reversible, in-situ protecting group for amines. Three strategies for the reversible protection of amines using carbon dioxide were developed and evaluated. Further, a chemoselective reaction was performed using carbon dioxide to protect a reactive amine and consequentially direct reactivity elsewhere within the same molecule. The carbon dioxide-protection technology developed has significant impact in multi-step industrial syntheses, as reversible, in-situ protection with carbon dioxide could eliminate the need for separate protection and deprotection unit operations. Lastly, a study was performed on the thermal degradation and stabilization of PVC in the presence of both plasticizers and thermal stabilizers. The study combined both model compound experiments as well as work with bulk PVC blends to gain a holistic understanding of the processes that take place during the degradation and stabilization of PVC. A bio-based plasticizer was investigated as a replacement for petroleum-based phthalate plasticizers. Additionally, two novel thermal stabilizers for PVC were presented and evaluated.

Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 2002. / Document électronique également accessible en format PDF. CaQCU

Thesis (M. Phil.)--University of Hong Kong, 1990.

xv, 277 p. A print copy of this title is available from the UO Libraries, under the call number: SCIENCE TP1180.V48 V46 2007 / This dissertation examines the political, scientific, social, environmental, and health debates surrounding the use of polyvinyl chloride (commonly called vinyl), a plastic many public health advocates and activists contend has a toxic lifecycle with deleterious human and ecological impacts at every stage. Using extensive documentary research and in-depth interviews, I answer a basic question: how and why have major stakeholders politicized PVC in recent decades? I find the strength of the anti-PVC movement lies largely in its broad based constituency: it includes professionals within the health care and green building industries, as well as labor unions and environmental health advocates. However, I raise critical questions about the movement's strategy of situating itself as a market-based movement where limited analysis is given to the greater environmental and health impacts of the health care and building industries as a whole. / Adviser: Gregory McLauchlan

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Brazil has a high deficit of housing. However, it is known that adequate housing condition may reflect in improvements in the quality of life of the population. Aiming the solution of this problem and the delivery of increased productivity and quality to residential buildings, new techniques and new materials are developed. This study has sought a better understanding of the innovative building system composed of polyvinyl chloride profiles - PVC - filled with concrete through assessments made during and after construction. Six housing complexes were visited in different cities of the state of Rio Grande do Sul, BR, where the questionnaires were administered to residents. The following housing complexes were examined: Canoas Minha Terra II, Valparaíso Condominium, São Luiz Condominum, Loteamento Park Novo Hamburgo, Residential Terra Nativa and Park São Pedro whose typology and constructive standards were diverse. In addition, the implementation of the Canoas Minha Terra I project was accompanied in order to identify the main construction stages of a building with such construction system and to take samples for testing. These samples showed inferior results when compared to the appropriate norms. The residents reviews were positive about the comfort and appearance of the building. However, the main problem reported and identified in loco was the excessive accumulation of moisture on the walls following condensation, and consequently the appearance of mold. This problem was less frequent in the condominium that had internal finishing of the rooms with no exposed PVC. Therefore, the constructive system at stake provides more rapidity, transportation facility and execution when compared to conventional methods. However, it requires projective artifices such as coating or increased ventilation, so that users do not have inconveniences generated by the accumulation of water on the walls. / O Brasil possui um alto déficit habitacional, todavia, sabe-se que a adequada condição de moradia pode refletir melhorias na qualidade de vida da população. No sentido de resolver tal problema e agregar maior produtividade e qualidade às construções residenciais, novas técnicas e novos materiais são desenvolvidos. Essa pesquisa buscou um melhor entendimento do sistema construtivo inovador composto por perfis de policloreto de vinila PVC preenchidos por concreto através de avaliações durante e pós-construção. Foram visitados seis conjuntos habitacionais em distintas cidades do estado do Rio Grande do Sul, BR, para aplicação de questionários aos moradores. Os conjuntos habitados inspecionados foram: Canoas Minha Terra II, Condomínio Valparaíso, Condomínio São Luiz, Loteamento Parque Novo Hamburgo, Residencial Terra Nativa e Parque São Pedro de variadas tipologias e padrões construtivos. Ainda, foi acompanhada a execução do empreendimento Canoas Minha Terra I com a finalidade de identificar as etapas principais da construção de uma edificação com tal sistema construtivo e também retirar amostras para ensaio. Essas amostras apresentaram resultados inferiores às normas pertinentes. Já as avaliações dos moradores foram positivas quanto ao conforto e aparência da edificação. Entretanto, o principal problema relatado e também identificado in loco foi o excessivo acúmulo de umidade nas paredes por efeito da condensação e, consequentemente, o aparecimento de fungos. Tal problema obteve menor frequência no condomínio que possui acabamento interno dos ambientes sem deixar o PVC exposto. Logo, o sistema construtivo em questão confere maior rapidez, facilidade de transporte e execução se comparado aos métodos convencionais. Contudo, ele necessita de artifícios projetuais, tais como revestimento ou incremento de ventilação, para que os usuários não tenham incômodos gerados pelo acúmulo de água nas paredes.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-09-28T19:19:22Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação PPGEM - Francisco Alves de Lima Júnior.pdf: 7760423 bytes, checksum: b0d747f5e3c3795b57483f19b676a178 (MD5) / Made available in DSpace on 2016-09-28T19:19:22Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação PPGEM - Francisco Alves de Lima Júnior.pdf: 7760423 bytes, checksum: b0d747f5e3c3795b57483f19b676a178 (MD5) Previous issue date: 2016-02-03 / A pesquisa que deu origem a esta dissertação foi realizada a partir de dados de propriedades mecânicas obtidos de testes e ensaios de inspeção, performance e controle de qualidade, executados em tubos fabricados em material polimérico, com e sem orientação molecular. Foram eles: Resistência ao Impacto, Resistência à Pressão Hidrostática Interna, Grau de Gelificação e Resistência ao Cloreto de Metileno, Resistência à Compressão Diametral, Estabilidade Dimensional, Classe de Rigidez e Resistência ao Achatamento, Resistência o Prolongamento da Fissura e Grau de Orientação Molecular. Para obtenção dos dados, os materiais foram testados em condições reais e extremas de operação, em sistemas, equipamentos, instrumentos, “softwares” e acessórios especificados, montados e calibrados em laboratório e instalações fabris, conforme normativos técnicos. Para registros dos dados foram utilizados sistemas informatizados acessórios aos equipamentos, assim como planilhas eletrônicas e “softwares” de controle estatístico e descritivo e para parametrização de ensaios mecânicos. Os dados e resultados foram analisados segundo parâmetros e critérios de estabilidade dimensional, tenacidade e rigidez, resistência à pressão hidrostática interna, ao impacto, ao cloreto de metileno, à compressão diametral e ao prolongamento de fissura, associados ao seu grau de orientação molecular, baseados em bibliografias e normas técnicas referentes às análises, ensaios e materiais empregados. Estes critérios abrangem o dimensionamento, cálculo e comparação de parâmetros, quando do material aplicado ao projeto de tubos. Foram avaliados os efeitos resultantes da orientação molecular nas propriedades mecânicas finais dos produtos acabados. Foi observado que o processo de orientação molecular proporcionou ao material maior tenacidade, maior resistência à transmissão da fissura, bem como maiores resistências a fadiga, impacto, tração, compressão e deformação, maior módulo de elasticidade, e consequente diminuição de coeficientes de segurança aplicados ao projeto. / The research that led to this work was made from data obtained mechanical properties testing and inspection testing, performance and quality control, performed in tubes made of polymer material, with or without molecular orientation. They were: Impact Resistance, Resistance Pressure Internal Hydro, Grade Gelling and resistance Methylene Chloride, Resistance Diametral compression, dimensional stability, Class of stiffness and resistance to flattening, resistance to extension of the fissure and Molecular Orientation degree. To obtain the data, the materials have been tested in real and extreme operating conditions, systems, equipment, instruments, “software” and accessories specified, assembled and calibrated in laboratory and manufacturing facilities, as technical regulations. For data records were used computer accessories systems for equipment, as well as spreadsheets and statistical and descriptive control “software” for parameter setting and mechanical tests. The data and results were analyzed according to parameters and dimensional stability criteria, toughness and rigidity, resistance to internal hydrostatic pressure, impact, methylene chloride, diametral compression and extension cleft associated to the degree of molecular orientation, based in technical bibliographies and rules regarding analyzes, testing and materials used. These criteria cover the design, calculation and parameters comparison, when the material applied to the pipe design. The effects resulting from the molecular orientation in the final mechanical properties of finished products. It was observed that the molecular orientation process provided the material greater toughness, greater resistance to the transmission of the crack, as well as higher resistance to fatigue, impact, tensile, compression and creep, higher modulus, and thus reduce safety coefficients applied to project.

Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-16T10:09:19Z (GMT). No. of bitstreams: 1 RodolfoJunior_Antonio_D.pdf: 6966645 bytes, checksum: 4b063523c75c2d8c912fc38efa499563 (MD5) Previous issue date: 2010 / Resumo: Nanocompósitos de poli(cloreto de vinila) (PVC) flexível, com óxidos de cobre (II), molibdênio e zinco, e argila organicamente modificada (O-MMT), foram preparados utilizando-se o processo de pré-esfoliação da argila em uma mistura de plastificantes a quente, seguido da intercalação no estado fundido. Nanocompósitos de microestrutura híbrida intercalada/parcialmente esfoliada foram obtidos em todas as situações avaliadas, o que foi demonstrado diretamente pelos resultados de difratometria de raios X (DRX) e microscopia eletrônica de transmissão (MET), bem como indiretamente pelo incremento significativo do módulo de elasticidade das composições estudadas. A modelagem dos resultados de módulo de elasticidade mostrou que o processo de preparação utilizado permitiu o efetivo desenvolvimento da razão de aspecto da argila, que atingiu valores comparáveis com os obtidos por outros pesquisadores, em diferentes matrizes poliméricas e processos de preparação de seus nanocompósitos. As propriedades de combustão e emissão de fumaça, quando estudadas por calorimetria de cone em fluxo radiante de 50 kW m-2, mostraram que os óxidos metálicos possuem efeito bastante significativo, notadamente naquelas propriedades mais importantes quanto aos requisitos de segurança em situação de incêndio, retardando a liberação de calor e a emissão de fumaça das amostras estudadas, além de reduzir suas quantidades absolutas. A presença da O-MMT afeta somente de maneira discreta estas propriedades, e pouca interação foi observada na utilização conjunta destes dois aditivos. Os resultados fornecem ainda indicativos de que a combinação entre CuO e MoO3 é a que apresenta o melhor balanço de propriedades de combustão, uma vez que reduz o calor liberado e promove a supressão da fumaça de maneira mais eficiente. As formulações contendo ZnO, por conta de seu forte caráter de ácido de Lewis, indicam uma redução menos pronunciada da fumaça emitida durante o processo de combustão, quando em comparação com os óxidos de cobre (II) e molibdênio / Abstract: Poly(vinyl chloride) (PVC), copper (II), molybdenum and zinc oxides, and organically modified montmorillonite nanocomposites were prepared in a melt blending intercalation process. The morphology of the nanocomposites was evaluated using X-ray diffractometry (XRD) and transmission electron microscopy (TEM), and indirectly by the increment of the Young modulus of the formulations studied. The modeling of the Young modulus showed that the process of nanocomposite preparation allowed the increase of the aspect ratio of the clay particles, whose values were comparable to those nanocomposites obtained by other researchers, using different polymeric matrices and methodologies. Combustion and smoke emission properties, when studied using cone calorimetry at a radiant flux of 50 kW m-2, revealed that the metallic oxides have a significant effect on both combustion and smoke suppression properties, mainly those closely linked with safety in fire situations, retarding heat and smoke release, and lowering their absolute values. The presence of O-MMT only affects these properties discretely, and little interaction was observed in the joint use of these additives. Results also provide indications that the combination of the CuO and MoO3 present the best balance of combustion properties, as it reduced the heat released and promoted the suppression of smoke more efficiently. The formulations containing ZnO, because of their strong Lewis acid character, indicated a less pronounced reduction of smoke released during the combustion process, when compared with copper (II) and molybdenum oxides / Doutorado / Ciencia e Tecnologia de Materiais / Doutor em Engenharia Química