163 resultados para acrylonitrile butadiene(NBR) rubbers


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The quality in construction is increasingly a concern in this sector, in view of the occurrence of problems in civil works, even when a contractor is certified by ISO 9001. The ISO 9001 certification does not ensure the maintenance of quality because it only establishes the requirements for a quality management system (QMS) to ensure standardization of processes and products. With the development of ISO 15575, standard performance, the builders took on a quality parameter with the requirements established by this Standard, which must be met. Thus, the implementation of a quality management system (QMS) becomes essential, showing users the concern for quality. This study aimed to verify, through a case study, the impact of NBR 15575 quality construction and how that standard of performance may be the key element of ISO 9001 to ensure quality maintenance of civil works

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The use of environmental management systems - EMS has shown to be a key tool for addressing the environmental aspects and impacts of an organization. The vast majority of EMS based on the requirements of ISO 14001:2004, as it is a globally recognized standard and adopt its recommendations is considered to be a guarantee of fulfilling the basic requirements of an EMS. Despite all the benefits that the system provides, we still find many problems in the implementation of EMS, especially in small and medium enterprises or SME. Most of the difficulties of implementation is related to intrinsic factors that companies of this size have, and issues related to the models and methods used to implement an EMS. Thus, this work aimed to assess whether the guidelines of ISO 14005:2012 meet the needs of SMEs for the effective implementation of an environmental management system. For it has been identified in the relation between SMEs and EMS the majof intrinsic problems of SMEs to implement (PII), such as lack of financial and human resources, and lack of commitment from top management to the SGA. Also was also pointed the main implementation issues related to ISO 14001 (ABNT, 2004) or the models or methods (PIM), highlighting the lack of environmental performance criteria, and the need for a path or sequence of steps for implementation. The study of ISO 14005 (ABNT, 2012) showed that the standard guidelines and implementation examples proposed, include solutions for all problems related to EMS implementation SMEs

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This work brings to its content proposed deployment of a system of quality management in paving asphalt based on the elaboration of a basic training to meet those entering this area of civil engineering at a technical manual for the implementation of major services running on paving of roads. The training was designed to serve both those entering the field of asphalt paving, synthesizing the complex processes involved in paving services and providing an overview of the steps in implementation thereof, as well as entrants must meet the enterprise user of this system, providing them an idea of the method used by the company designing the paving of roads. The technical manual presented in turn, has 8 (eight) of the main services components of a work of paving, which are: Mobilization and Maintenance of construction site, Regularization and subfloor preparation, execution or sub-base BGS base (graded gravel plain), Execution of sub-base or base BGTC (graded gravel treated with cement), Implementation of subbase or base Macadam hydraulic Priming bituminous waterproofing, asphalt binder Priming and finally the execution flexible pavement - HMA (hot milled asphalt concrete). These services are presented in the form of IT-Education work, this seven items are presented that guide the performance of services, thus providing overall guidelines to perform the services described in it. The development of IT's was based on experiences in day-to-day paving near the theoretical precepts presented in the literature, so the conditions specified in these documents aim to always guide the implementation of services in general, giving the process a versatility major operation, as this work takes into account the dynamics of such services, as well as the variety of their execution according to local conditions and specified in the project. So in general we can say that this ... (Complete abstract click electronic access below)

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The progressive growth of the population and the increase of sewage generated has demanded of society and public policies that, besides the collection network deployment is carried out the treatment and proper disposal of treated sewage in all brazilian municipalities. The aim of this study was to monitor and evaluate the work of implementation of a Sewage Treatment Plant (STP) in Guaratinguetá city of São Paulo state, to identify the compliance with legal requirements and the NBR 12,209/2011. The construction of this ETE met all the requirements of NBR 12209/2011 and benefited a large portion of population with the sewage treatment. Based on the results of this assessment it was concluded that the construction of a STP is relatively simple, differing only on the legal requirements related to the location, area for the construction and materials used in the work. The knowledge generated in this study will assist the public policies in the implementation of STPs in municipalities that do not yet have this basic sanitation

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Objetivou-se neste trabalho, comparar a resistência à compressão de tijolos de solo-cimento fabricados com o montículo do cupim Cornitermes cumulans (Kollar, 1832), com tijolos que utilizaram como matéria prima um NEOSSOLO QUARTZARÊNICO (Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), 1999), ambos submetidos a duas idades de cura (07 ou 28 dias). O experimento foi montado em delineamento inteiramente casualizado, em esquema fatorial 2x2, sendo analisados dois cofatores: a matéria prima base e a idade de cura. Os ensaios físicos e mecânicos obedeceram às prescrições das normas da Associação Brasileira de Normas Técnicas NBR-8492 (ABNT, 1982) e NBR-8491 (ABNT, 1984). Concluiu-se que a resistência à compressão dos tijolos foi maior com o aumento das idades de cura. O tratamento T4 apresentou maior valor de resistência à compressão, não diferindo estatisticamente dos tratamentos T2 e T1. Os tijolos fabricados com o montículo do cupim C. cumulans (Kollar, 1832) apresentaram diminuição da absorção de água com o aumento das idades de cura, o que normalmente corresponde a um maior aumento da resistência à compressão, ao contrário dos que utilizaram o NEOSSOLO QUARTZARÊNICO (Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), 1999).

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Reusing scrap tires has become a worldwide challenge, especially due to the great difficulty in finding ecologically and economically feasible ways to dispose of them. This has led to the creation of specific programs and legislation for reusing scrap tires. Research has shown that a certain percentage of scrap tire rubber can be added to asphalt compositions, and this has become a worldwide practice. This paper describes the properties of four asphalt compositions modified with scrap tire rubber (STR) prepared in the laboratory. These properties are then compared with those of asphalt modified with styrene butadiene styrene (SBS), a synthetic polymer and one of the most common modifiers, to verify the feasibility of using scrap tire rubber as a substitute for SBS. The scope of this study does not include an analysis of how STR affects end-of-life asphalt. The main findings indicate that STR is a potential substitute of SBS in paving material, and although it does not meet some of the standard specifications when compared with SBS, these issues can be overcome by proper care during storage and transportation. The substitution of SBS by STR also showed the potential for about 10% in expenditure savings. (C) 2012 Elsevier Ltd. All rights reserved.

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A auditoria de sistema de gestão da qualidade é utilizada pelas organizações para melhorar o seu desempenho por meio de avaliações sistemáticas dos processos. Ao mesmo tempo, a atividade de auditoria vem sendo questionada quanto à sua capacidade de promover essa melhoria. Diante deste cenário, este artigo objetiva analisar fatores que afetam o processo de auditoria de certificação do sistema de gestão da qualidade, de modo a indicar oportunidades de melhoria das auditorias. A pesquisa é delimitada a auditorias no setor aeroespacial, que são orientadas pela NBR 15100. Foi realizada uma survey com auditores experientes nos anos de 2009 e 2010. São identificados fatores como comunicação, seleção da equipe, conhecimento do setor e os resultados mostram a existência de discrepâncias consideráveis entre o nível de importância e de aplicação desses fatores nas organizações auditadas.

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This paper presents results of physical and mechanical tests in polyester (PET) and polypropilene (PP) nonwoven geotextiles that were exposed to weathering conditions (solar radiation, humidity, wind, rain) after some specific periods of exposure (1, 2, 3 and 4 months). ASTM D5970 and Brazilian standards (NBR) recommendation were followed in this research. Results show variations in tensile properties and in the mass per unit area. Variations in the deformations were more significant in the PP geotextile when compared to the PET geotextile.

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Octakis(cyanopropyldimethylsiloxy)octasilsesquioxane was prepared and characterized by C-13, Si-29 NMR (MAS), SEM, FF-IR, XRD and thermogravimetric techniques. The four groups alpha, beta, gamma, kappa (to the terminal silicon atom), associated with an acrylonitrile, were clearly seen in the C-13 NMR (alpha-CH2 at 17.9; P-CH2 at 31.3; gamma-CH, at 50.4; K-C N at 59.0 ppm). The Si-29 NMR spectrum of the final product, exhibits only Q type silicon signal, ascribed to Q(4) (-118.0 ppm). The presence of acrylonittile substituted for octameric cube confers a relative change phase and thermal stability to the material. With regard to the applications for this new material, it was intended, in this case, to react with Na-2[Fe(CN)(5)NH3] by chemical substitution. This composite was incorporated into a carbon paste electrode and the electrochemical studies were performed by cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode, showed one redox couples with formal potential (E-1/2(ox)) = 0.24 V versus SCE. (c) 2006 Elsevier B.V. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Avaliaram-se os efeitos de diferentes porcentagens (0, 10, 20 e 30%) de inclusão da torta de macaúba (TM) no comportamento ingestivo de 24 cordeiros Santa Inês, com média de cinco meses de idade e peso vivo de 23,9kg, distribuídos em delineamento em blocos ao acaso, com quatro tratamentos e seis repetições, durante 60 dias de confinamento. Foram avaliados os tempos médios despendidos com alimentação, ruminação (TR), ócio (TO), tempo de mastigação total (TMT), eficiência de alimentação (EA MS e EA FDN) e eficiência de ruminação, além do número de bolos ruminados (NBR) e número diário de mastigações merícicas (MMnd). A adição de TM à dieta aumentou linearmente o TR, TMT, NBR, MMnd e EA FDN e reduziu de forma linear o TO, em consequência do maior teor de fibra em detergente neutro das dietas com o coproduto. Mesmo com o aumento no TMT, não foi verificada diferença no consumo e na eficiência de ruminação e alimentação da matéria seca, possivelmente em razão da baixa efetividade de fibra da TM, demonstrando o potencial de utilização desse coproduto na dieta de ovinos em crescimento.

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O principal objetivo deste trabalho é verificar, por meio de uma pesquisa tipo survey, os benefícios e as dificuldades da adoção de Sistemas de Gestão Ambiental ISO 14001 em empresas industriais do Estado de São Paulo. Para tal, um questionário foi enviado para 194 empresas constantes da base de dados do INMETRO (Instituto Nacional de Metrologia, Normalização e Qualidade Industrial) e respondido por 69 delas, representando uma taxa de retorno de 35,36%. Duas hipóteses foram estabelecidas para realização do estudo: uma enunciando os potenciais benefícios e outra as dificuldades da gestão ambiental com base na norma NBR ISO 14001. Estas hipóteses foram parcialmente comprovadas. O artigo está estruturado da seguinte forma: introdução, sistema de gestão ambiental, norma NBR ISO 14001, método de pesquisa, apresentação e análise dos resultados, conclusão e referências bibliográficas.