614 resultados para Aderência
Resumo:
Esta tese apresenta o desenvolvimento e aplicação de modelos de turbulência, transição laminar-turbulenta e de interações fluido-estrutura ao escoamento externo em cilindro rígido estacionário e em vibrações induzidas por vórtices. Tais desenvolvimentos foram realizados no código ReFRESCO, baseado em técnicas de dinâmica de fluidos computacional (CFD). Realizou-se um estudo quanto ao desempenho do modelo k- SST em extensa faixa de números de Reynolds, segundo o qual se identificaram as deficiências de modelagem para este escoamento. A modelagem adaptativa das escalas (SAS) e o modelo de transição por correlações locais (LCTM), ambos combinados ao SST, melhoraram a aderência aos resultados experimentais para este escoamento, em uma contribuição original deste trabalho. A aplicação de técnicas de verificação e validação possibilitou a estimação de incertezas e erros para os modelos e números de Reynolds e também de identificada como outra contribuição deste trabalho. A combinação da modelagem em SST, SAS e LCTM com movimentos impostos de realizada para números de Reynolds moderados, diferentes frequências e amplitudes de vibração, algo que poucas publicações abordam em detalhes. Com relação aos movimentos livres, este trabalho traz contribuições com a aplicação dos modelos SST e SAS ao estudo de vibrações induzidas por vórtices em dois graus de liberdade, baixa razão de massa e números de Reynolds moderados, mais altos do que normalmente observados na literatura. Por fim, a investigação da importância relativa de efeitos da turbulência aos casos de movimentos livres e impostos, com relação ao caso de cilindro estacionário, comprovou a conjetura formulada na parte inicial deste trabalho, no que tange à escolha do modelo de turbulência em determinadas aplicações. Tal escolha mostrou-se menos decisiva no caso do cilindro em movimento imposto e ainda menos nos movimentos livres, em comparação ao caso estacionário, uma vez que a resposta em movimentos do corpo filtra grande parte dos efeitos turbulentos de ordem superior. Esta observação mostra-se relevante, uma vez que pode permitir simplificações na modelagem e aplicação de ferramentas de CFD em uma classe importante de projetos de engenharia.
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Para que a sustentabilidade seja gerenciada e praticada de maneira efetiva, ela deve ser mensurada, utilizando-se de métodos de avaliação da sustentabilidade. Estão disponíveis diferentes métodos de avaliação, que geralmente reduzem o resultado desse levantamento à indicadores de desempenho ambiental, econômico e social (POPEA; ANNANDALE; MORISON-SAUNDERSB, 2004). Uma das denominações mais bem aceitas e difundidas para a conjunção da dimensão ambiental e econômica é conhecida por avaliação de eco eficiência (AEE). Eco eficiência é o \"aspecto da sustentabilidade que relaciona o desempenho ambiental de um sistema de produto ao valor do sistema de produto\" (ISO, 2012). Estão disponíveis diferentes métodos de AEE, porém sem evidência das suas semelhanças e particularidades e como essas características influenciam na escolha do método mais adequado de AEE em relação às potenciais aplicações O objetivo desta pesquisa é, portanto, analisar e indicar os tipos de métodos de avaliação de eco eficiência (AEE) mais adequados para ações gerenciais nas quais caibam tais abordagens. Foram selecionados onze métodos de AEE, a partir do estabelecimento de critérios de caracterização desses métodos, a saber: BASF, Bayer, EcoWater, Hahn et al., Kuosmanen e Kortelainen, MIPS, NRTEE, UN ESCAP, UN, TU Delft, e WBCSD. Identificaram-se, ainda, quatro potenciais aplicações: (i) Monitoramento de processo com vistas à melhoria contínua; (ii) Selecção e classificação de produtos; (iii) Atendimento a requisitos legais e outros requisitos; e, (iv) Marketing, rotulagem de produtos e comunicação ambiental. A partir dos elementos metodológicos estabelecidos pela norma ISSO 14045 (2012) e do conhecimento obtido dos métodos de AEE, determinaram-se quatro requisitos pelos quais os métodos e os potenciais aplicações foram avaliados: (i) Tipo de indicador de desempenho ambiental; (ii) Tipo de indicador de valor de sistema de produto; (iii) Abrangência de aplicação; e, (iv) Tipo de indicador de eco eficiência. Aplicando-se estes requisitos nos métodos de AEE e nos potenciais usos, concluiu-se que quanto à aplicações em termos de monitoramento de processos com vistas à melhoria continua os métodos de AEE recomendados foram Bayer, NRTEE, WBCSD e UN. Para situações de seleção e classificação de produtos os métodos BASF, EcoWater, Kuosmanen e Kortelainen, MIPS, Hahn et al., TU Delft, UN ESCAP e UN demonstraram ter boa aderência. No que se refere a usos voltados ao atendimento de requisitos legais e/ou de outras naturezas, os métodos NRTEE, WBCSD e UN são os mais indicados. Em aplicações de marketing, rotulagem e comunicação foram indicados os métodos BASF, EcoWater e MIPS. Finalmente, concluiu-se que, para a escolha adequada da metodologia para uma AEE, conhecimento prévio das características de cada abordagem é necessário.
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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014
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O objetivo deste trabalho é avaliar os fatores que afetam a determinação dos spreads nas operações de Certificado de Recebível do Agronegócio (CRA). Foram selecionadas na amostra todas as emissões registradas na ANBIMA entre os anos de 2012 e maio de 2016. Verificou-se que a remuneração desse título é influenciada principalmente pela presença de reforço de crédito/garantias, pelo setor originador dos recebíveis e pela companhia securitizadora. Em uma segunda análise mais detalhada e acrescentando as variáveis uma a uma de forma a testar a aderência do modelo, encontraram-se evidências de que o tamanho da emissão e o percentual de subordinação são importantes variáveis de controle na determinação do spread. Ao incluirmos a variável rating, esta passa a ser relevante e da mesma forma acontece com a garantia, demonstrando que o percentual de subordinação reduz o spread do título, mas quando se acrescenta garantia, ele deixa de ser significativo. O sinal da variável garantia é positivo e demonstra que se há a necessidade de incluir garantias na emissão, é porque provavelmente é essencial para que a emissão ocorra. Por fim, a variável securitizadora mostrou-se relevante, indicando que o investidor leva em consideração a qualidade da mesma para a precificação do título.
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A presente dissertação tem por objetivo investigar os aspectos do processo de terceirização da atividade industrial em suas diversas etapas. São estudadas todas as fases, iniciando-se pelo planejamento das atividades e segue com o estudo da viabilidade econômica, com o levantamento dos benefícios potenciais (identificados e separados). Identificação dos fornecedores potenciais, desenvolvimento dos produtos, aprovação dos produtos, estudo da estrutura de custo e do preço a ser praticado, finalizando com o início dos fornecimentos. Para tanto, foi realizado o estudo de um caso de terceirização da produção em uma indústria de produtos para iluminação. O objetivo desta terceirização foi otimizar a variedade dos produtos fabricados sem entretanto, alterar o portifólio dos produtos comercializados . Para tanto, decidiu-se por desenvolver novas fontes de fornecimento para os produtos com menor volume de produção e com maior complexidade em suas construções. A planta de produção da empresa "Alfa" está localizada no estado de Nuevo Leon no México e tem como objetivo fornecer produtos de iluminação (lâmpadas incandescentes e fluorescentes) para os países da área do NAFTA (México, Canadá e Estados Unidos). O trabalho foi conduzido por uma equipe multidisciplinar, operando em estrutura matricial, localizada em pontos geograficamente distintos em função da atividade requerida de cada um dos membros da equipe. O trabalho mostra que este processo é viável, mas que envolve um significativo grau de complexidade para que se possa obter os resultados finais alinhados com as expectativas das partes envolvidas no início do processo. Observa-se que o comprometimento da alta administração é fundamental para garantir os meios e alinhamento da equipecom as estratégias definidas, bem como suportar a aderência da atividade aos preceitos estabelecidos. Conclui-se que a estruturação deste processo pode garantir melhores resultados nos aspectos de custo dos produtos, tempo de realização do processo e qualidade dos produtos em conformidade com as especificações.(AU)
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O objetivo deste trabalho foi, através de pesquisa teórica para uma fundamentação filosófica, analisar como o estudo da Deontologia, observando as influências do Paradigma Educacional Emergente, pode contribuir com a formação do Profissional de Educação Física e como, com aderência aos conceitos de ser humano de Freire, Morin, Maturana e Varella e da legislação vigente, situa-se o ensino superior neste contexto. Princípios éticos foram observados como imprescindíveis para o desenvolvimento profissional em Educação Física, e confirmamos esta necessidade no decorrer do trabalho. Utilizamos como instrumentos de análise, conceitos filosóficos básicos da distinção de moral e ética em La Taille e Severino; estudos da preparação Ética e Bioética em Tojal; novos paradigmas da ciência segundo os estudos de Santos; do Paradigma Educacional Emergente em Moraes e das relações de ensino-aprendizagem do Ensino Superior através do pensamento de autores como Severino, Libâneo, Saviani, Cunha, Dias Sobrinho e Arroyo.
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Systemic Arterial Hypertension – SAH – is defined as the syndrome which its main feature is the presence of high tensional levels, associated with alterations of functional or structural levels in the organs that it strikes. Its specific causes are not very well bounded and have an asymptomatic character. Due to its chronicity it requires adherence to the treatment plan in a systematic and permanent manner, implicating in lifestyle changes, combined or not with the use of medication. The personality inventories have been largely used in the lineation of indicative traits of difficulties with the adherence to the treatment. In this sense, developed by Theodore Millon, the Millon Behavioural Medicine Diagnostic – MBMD is an instrument made from the consensus among healthcare professionals, aiming at identifying psychological factors that may compromise medical treatment so that they can be conducted in a way to enable a better adherence. Objective: evaluation of the evidence of validity of the Millon Behavioural Medicine Diagnostic – MBMD for a public of patients with hypertension, aiming at investigating the indicators implicated in the adherence or not to the anti-hypertensive treatment. Method: there was a group of 200 participants in a university hospital in the city of Natal/RN, males and females, ranging from 20 to 70 years old. An interview protocol was administered in order to obtain information about socio-demographic data, clinical history, healthcare habits and way of conducting treatment, and after, the administration of the MBMD followed. Results: by means of Factor Analysis it was verified that the organization proposed by the factors is favorable and it adjusts to the theory, allowing the visualization of other underlying constructs to the scales, with adequate adjustment indexes and satisfactory Cronbach’s alpha indicators. Besides, the MBMD revealed itself sensitive to the intragroup differences relative to the sex, age, schooling, marital status, profession, income, SAH history, diagnostic time, medication use, comorbidity presence, hyposodic diet, social support and adherence criteria variables. The utilization of such instrument in the evaluation of the adherence to the anti-hypertensive treatment show, therefore, indicators of validity.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
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This work aims to demonstrate the feasibility of a ceramic composite containing fiber in the rubber manufacturing interlocking blocks. Gravel, sand, cement, rubber and fiber: the processes of manufacture and assembly of blocks produced and the various formulations studied with different proportions between the constituent elements were addressed. Mechanical properties were determined for the different formulations, compressive strength, diametral compressive strength, water absorption and apparent density, obeying the rules related to each property. It was concluded that the addition of rubber fiber gave the concrete studied resistance lower than conventional concrete which can be verified on the microstructural analysis obtained by SEM, which revealed the presence of pores and the low adhesion between the fiber and the matrix compression (tire fiber / cement paste). The composite of more viable tire BCPB1 (1/2) fiber can be used in places requests as light squares, pavements, roads and other cycle as well as in the manufacture of the curb and gutter, by having compressive strength in about 20 MPa
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It is considered that the Strategic Alignment IT is the first step within the IT Governance process for any institution. Taking as initial point the recognition that the governance corporate has an overall view of the organizations, the IT Governance takes place as a sub-set responsible for the implementation of the organization strategies in what concerns the provision of the necessary tools for the achievement of the goals set in the Institutional Development Plan. In order to do so, COBIT specifies that such Governance shall be built on the following principles: Strategic Alignment, Value Delivery, Risk Management, Performance Measurement. This paper aims at the Strategic Alignment, considered by the authors as the foundation for the development of the entire IT Governance core. By deepening the technical knowledge of the management system development, UFRN has made a decisive step towards the technical empowerment needed to the “Value Delivery”, yet, by perusing the primarily set processes to the “Strategic Alignment”, gaps that limited the IT strategic view in the implementation of the organizational goals were found. In the qualitative study that used documentary research with content analysis and interviews with the strategic and tactical managers, the view on the role of SINFO – Superintendência de Informática was mapped. The documentary research was done on public documents present on the institutional site and on TCU – Tribunal de Contas da União – documents that map the IT Governance profiles on the federal public service as a whole. As a means to obtain the documentary research results equalization, questionnaires/interviews and iGovTI indexes, quantitative tools to the standardization of the results were used, always bearing in mind the usage of the same scale elements present in the TCU analysis. This being said, similarly to what the TCU study through the IGovTI index provides, this paper advocates a particular index to the study area – SA (Strategic Alignment), calculated from the representative variables of the COBIT 4.1 domains and having the representative variables of the Strategic Alignment primary process as components. As a result, an intermediate index among the values in two adjacent surveys done by TCU in the years of 2010 and 2012 was found, which reflects the attitude and view of managers towards the IT governance: still linked to Data Processing in which a department performs its tasks according to the demand of the various departments or sectors, although there is a commission that discusses the issues related to infrastructure acquisition and systems development. With an Operational view rather than Strategic/Managerial and low attachment to the tools consecrated by the market, several processes are not contemplated in the framework COBIT defined set; this is mainly due to the inexistence of a formal strategic plan for IT; hence, the partial congruency between the organization goals and the IT goals.
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In this work it is assessed the performance of Portland cement-based mortar to the grouting of type II ceramic plates with the addition of unusable tire rubber powder. It is presented a bibliographical review about the subject in which is done the theoretical and methodological foundation of the whole investigative process. The analyzed universe comprises a sample of mortar to the grouting of conventional ceramic plates type II (reference sample) and five more samples to the grouting of ceramic plates type II, which were made up of the addition of unusable tire rubber powder in the respective proportion (in mass) of 4%, 8%, 12%, 16% and 20%. These mortar samples were subject to the trials of determination of the consistency index (Brazilian Standard NBR 13276:2005), water retention ( Brazilian Standard NBR 14992 Attachment B:2003), permeability in 240 minutes (Brazilian Standard NBR 14992 Attachment G:2003), absorption of water by immersion (Brazilian Standard NBR 9781:2013), resistance to compression (Brazilian Standard NBR14992 Attachment D: 2003), resistance to traction in the flexion (Brazilian Standard NBR 13279:2005), resistance of traction adherence (Brazilian Standard NBR 14081 part 4:2012) and hardened mass density (Brazilian Standard NBR 13280: 2005). It has been found out from the analyzes of the results in the trial the following situation: the reference mortar used met the established requirements in the norms of specifications corresponding to only six from the eight parameters assessed in the research; the mortar with addition of 4,0% of tire rubber powder met the established requirements corresponding to only the resistance to compression and the resistance of adherence to traction. Thus, the other kinds of mortar with addition of 8,0 %, 12,0 %, 16,0 % and 20,0 % of tire rubber powder met the requirements of specifications corresponding to only the resistance to compression and the resistance of adherence to traction. This result concludes that the adding of tire rubber powder does not grant improvement to the mortar of type II grouting to the laying of ceramic plates.
Resumo:
In this work it is assessed the performance of Portland cement-based mortar to the grouting of type II ceramic plates with the addition of unusable tire rubber powder. It is presented a bibliographical review about the subject in which is done the theoretical and methodological foundation of the whole investigative process. The analyzed universe comprises a sample of mortar to the grouting of conventional ceramic plates type II (reference sample) and five more samples to the grouting of ceramic plates type II, which were made up of the addition of unusable tire rubber powder in the respective proportion (in mass) of 4%, 8%, 12%, 16% and 20%. These mortar samples were subject to the trials of determination of the consistency index (Brazilian Standard NBR 13276:2005), water retention ( Brazilian Standard NBR 14992 Attachment B:2003), permeability in 240 minutes (Brazilian Standard NBR 14992 Attachment G:2003), absorption of water by immersion (Brazilian Standard NBR 9781:2013), resistance to compression (Brazilian Standard NBR14992 Attachment D: 2003), resistance to traction in the flexion (Brazilian Standard NBR 13279:2005), resistance of traction adherence (Brazilian Standard NBR 14081 part 4:2012) and hardened mass density (Brazilian Standard NBR 13280: 2005). It has been found out from the analyzes of the results in the trial the following situation: the reference mortar used met the established requirements in the norms of specifications corresponding to only six from the eight parameters assessed in the research; the mortar with addition of 4,0% of tire rubber powder met the established requirements corresponding to only the resistance to compression and the resistance of adherence to traction. Thus, the other kinds of mortar with addition of 8,0 %, 12,0 %, 16,0 % and 20,0 % of tire rubber powder met the requirements of specifications corresponding to only the resistance to compression and the resistance of adherence to traction. This result concludes that the adding of tire rubber powder does not grant improvement to the mortar of type II grouting to the laying of ceramic plates.
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Composite materials arise from the need for lighter materials and with bigger mechanical and thermal resistance. The difficulties of discard, recycling or reuse are currently environmental concerns and, therefore, they are study object of much researches. In this perspective the feasibility of using loofahs (Luffa Cylindrica) for obtainment of a polymeric matrix composite was studied. Six formulations, with 4, 5 and 6 treated layers and untreated, were tested. The loofahs were treated in boiling water to remove lignins, waxes and impurities present in the fibers. After that, they were dried in a direct exposure solar dryer. For the characterization of the composite, thermal (thermal conductivity, thermal capacity, thermal diffusivity and thermal resistivity), mechanical (tensile and bending resistance) and physicochemical (SEM, XRD, density, absorption and degradation) properties were determined. The proposed composite has as advantage the low fiber density, which is around 0.66 g/cm³ (almost half of the polyester resin matrix), resulting in an average composite density of around 1.17g/cm³, 6.0 % lower in relation to the matrix. The treatment carried out in the loofahs increased the mechanical strength of the composite and decreased the humidity absorption. The composite showed lower mechanical behavior than the matrix for all the formulations. The composite also demonstrated itself to be feasible for thermal applications, with a value of thermal conductivity of less than 0.159 W/m.K, ranking it as a good thermal insulator. For all formulations/settings a low adherence between fibers and matrix occurred, with the presence of cracks, showing the fragility due to low impregnation of the fiber by the matrix. This composite can be used to manufacture structures that do not require significant mechanical strength, such as solar prototypes, as ovens and stoves.
Resumo:
Composite materials arise from the need for lighter materials and with bigger mechanical and thermal resistance. The difficulties of discard, recycling or reuse are currently environmental concerns and, therefore, they are study object of much researches. In this perspective the feasibility of using loofahs (Luffa Cylindrica) for obtainment of a polymeric matrix composite was studied. Six formulations, with 4, 5 and 6 treated layers and untreated, were tested. The loofahs were treated in boiling water to remove lignins, waxes and impurities present in the fibers. After that, they were dried in a direct exposure solar dryer. For the characterization of the composite, thermal (thermal conductivity, thermal capacity, thermal diffusivity and thermal resistivity), mechanical (tensile and bending resistance) and physicochemical (SEM, XRD, density, absorption and degradation) properties were determined. The proposed composite has as advantage the low fiber density, which is around 0.66 g/cm³ (almost half of the polyester resin matrix), resulting in an average composite density of around 1.17g/cm³, 6.0 % lower in relation to the matrix. The treatment carried out in the loofahs increased the mechanical strength of the composite and decreased the humidity absorption. The composite showed lower mechanical behavior than the matrix for all the formulations. The composite also demonstrated itself to be feasible for thermal applications, with a value of thermal conductivity of less than 0.159 W/m.K, ranking it as a good thermal insulator. For all formulations/settings a low adherence between fibers and matrix occurred, with the presence of cracks, showing the fragility due to low impregnation of the fiber by the matrix. This composite can be used to manufacture structures that do not require significant mechanical strength, such as solar prototypes, as ovens and stoves.
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Objective: To evaluate in vitro the surface roughness and bacterial adhesion of nanoparticle composites, after being subjected to different finishing and polishing systems. Materials and Methods: 66 specimens were prepared, and 30 with Filtek Z350 XT (3M ESPE, USA) and 30 with the resin IPS Empress Direct (Ivoclar Vivadent, USA), divided into 6 groups (n = 10 ). Six specimens were prepared for analysis in scanning electron microscopy (SEM) .Each kind of resin was subjected to finishing and polishing systems: Sof-Lex Pop-On discs (3M ESPE, USA) and AstropolTM system (Ivoclar Vivadent , USA), featuring the experimental group. The control group did not undergo any kind of finishing and polishing technique. The average roughness (Ra) in both groups was measured using a roughness in the setting of 0.25 mm (cut off) and surface images obtained with photomicrographs taken with a scanning electron microscope (SEM) magnified 500 times. Bacterial adherence was evaluated by determining the absorbance (OD) of the suspension of adhered cells by spectrophotometer at 570 nm. The results were submitted for analyzed with 2-way ANOVA at α=.05 and Tukey multiple comparison tests. Results: Statistically significant differences were found between the groups in terms of roughness and bacterial adhesion. Filtek Z350 XT for resin were no differences between the tested finishing and polishing systems, where the system of lowest surface roughness was the Sof-Lex Pop-On. To the resin IPS Empress Direct, the finishing and polishing system Astropol, had lower results of surface roughness. As for bacterial adhesion, the lowest optical density value for Filtek Z350 XT was for the group that used the finishing and polishing system Sof-Lex Pop-On and the resin IPS Empress Direct the group that used the Astropol system. In addition, there was a positive correlation between surface roughness and bacterial adhesion on polished surfaces (r = 0.612) Conclusions: surface roughness and bacterial adhesion are closely related. The finishing and polishing Sof-Lex Pop-On system is more suitable for nanoparticulate Filtek Z350 XT and the finishing and polishing system Astropol for resin nanohíbrida IPS Empress Direct.