Modelo mecânico para estruturas lineares em concreto armado - uma abordagem acoplada entre a mecânica do dano e algoritmos de otimização

Modelos escritos através dos conceitos da Mecânica do Dano no Contínuo representam atualmente uma alternativa consistente para a simulação numérica do comportamento de estruturas constituídas por materiais quase frágeis, onde a perda de rigidez em função da fissuração crescente é o fator preponderante da resposta não-linear de seus elementos estruturais. No entanto, modelos de dano apresentam forte dependência de parâmetros internos usados para descrever os critérios e evolução das variáveis de dano, que devem ser calibrados adequadamente para uma resposta mecânica coerente da estrutura. Neste contexto, o artigo mostra um estudo sobre a calibração de parâmetros do modelo de dano de Mazars e sua aplicação na análise numérica de vigas e pórticos planos em concreto armado. O Método dos Mínimos Quadrados é adotado para resolver o problema, em conjunto com a técnica de Gauss-Newton. Em virtude da ausência de resultados experimentais para diversas classes de resistência do concreto, como referência para o processo de calibração, são adotados alguns modelos constitutivos teóricos tanto à tração quanto à compressão. Esse processo de calibração de parâmetros é incorporado a um modelo mecânico em elementos finitos para análise de barras em concreto armado, com a consideração conjunta dos mecanismos complementares de resistência ao cisalhamento, como efeito de pino, armadura transversal e engrenamento de agregados. Uma lei constitutiva exponencial para o decaimento da resistência à tração do concreto é proposta com o objetivo de simular o comportamento do tipo tension softening do material. Testes de simulação envolvendo o modelo proposto foram realizados, comparando-se com resultados experimentais e numéricos mostrando a boa precisão e capacidade de obtenção de cargas últimas em estruturas de barras em concreto armado.

Influência da deformação a frio na recristalização da liga Ti-30Ta para aplicações médicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Parâmetros hemetológicos da tilápia-do-Nilo: efeito da dieta suplementada com levedura e zinco e do estímulo pelo frio

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

Avaliação microbiológica e sensorial do guacamole conservado pelo frio

Avocado (Persea americana Mill.) is a product grown in tropical and subtropical regions and from it we can extract products like guacamole which is highly consumed in the Mexican culinary. The most used varieties for guacamole are the Hass and Fuerte. The present research had as objective to evaluate the microbiological and sensorial quality of the guacamole conserved through cold with no addition of additives. The microbiological analyses have shown the product reached satisfactory results as for the analysis of total and thermoenduring coliform < 3,0 UFC/g, Salmonella absent in 25g, Staphylococcus aureus and Bacillus cereus < 100 UFC/g, presenting values within the patterns set by RDC of Anvisa 12 of January 2nd 2001. The analyses of mesophile bacteria and the counting of mold and yeast reached values between 102 and 104 UFC/g and the psychrotropic bactéria presented values < 100 UFC/g. The sensorial anlyses have shown that the polyethylene package isn't effective in keeping the analysed sensorial parameters. Although the polyethylene and nylon packages had better results, however they didn't differentiate themselves so as the vacuum use.

Estabilidade físico-química de um produto de abacate acondicionado em diferentes embalagens e conservado pelo frio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparação entre ventilação mecânica convencional protetora e ventilação oscilatória de alta frequência, associadas ao NOi, quando aos efeitos sobre oxigenação, lesão histológica e dano oxidativo pulmonar em modelo de lesão pulmonar induzida em coelhos

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Implementação do OEE nas máquinas de laminação a frio

Through a description of the productivity problems experienced by some enterprises, to optimize their respective production lines, results of poor performance or low quality, the following work aims to explain and demonstrate the practical application of the theory of overall equipment effectiveness (OEE) on cold lamination machines in a steel industry . The project, to ensure your goal, is based on structuring a complete planning to increase levels of performance, availability and quality relating to rolling. On completion of the work, will be presented forecasts of future goals for the OEE, to search for continuous improvement and global standards of efficiency, taking into account, the sector the company operates, the history of the laminators, and financial aspects

Impactos causados por vibrações mecânicas em chapas de alumínio no processo de laminação a frio

This paper purpose is to analyze one of the main problems faced by cold rolling industry of the current time, the mechanical vibration. Factors such as strips with high velocity in order to increase the productivity and thickness becoming thinner and thinner cause the vibrations to be present at all times during rolling. These market requirements also drive the industry for technology development and thus bring the challenges that the operation of a new modern equipment and more powerful. The initial purpose is to analyze the forces that cause vibration in a rolling mill type four high with two stands, where is desirable to identify the origins of these vibrational forces to make possible dismiss them or at least control its intensity, in order to prevent damage in the rolling mill and ensure product quality to the customer. For it, will be used instruments to record and store the vibrations that occur during the lamination process. With this data will be able to analyze the characteristics of the vibrations and act at your elimination. At the end of the work is expected to demonstrate how important the critical view of the engineer in the analysis of graphics combined with the calculations of the natural vibration frequency and engagement of key parts of the laminator. With these two tools at hand, will be possible to increase the productivity of the rolling mill and act preventively in maintenance, thereby reducing your downtime and increasing its performance and efficiency

Verificação de pilares metálicos compostos constituídos por perfis formados a frio por meio de programa computacional

In this work, we discuss the procedures adopted for the design of built-up columns (laced and battened columns). Built-up columns are widely used in steel construction generally when the compression forces are relatively low and the column buckling lengths are large. They are commonly used in industrial buildings, for example, as posts for cladding, or as columns supporting a crane girder. Unlike columns with full section, in the case of built-up columns, it is necessary to evaluate the shear stiffness. In fact, the shear strength leads to a significant reduction of the critical load. In the context of this work, the components of the columns (chords, diagonals, posts, etc.) are formed by cold-formed members. In order to systematize and rationalize the verification of the built-up columns, this work aim to develop a computer program based on the standards NBR 14762, NBR 6355 and Eurocode 3, basically the considerations of the part EN 1993-1-1

Efeitos da suplementação de taurina ou flavonóides de cacau associado à achocolatado sobre a composição corporal, metabolismo de carboidratos e proteinas, desempenho fisico, dano muscular e estresse oxidativo em atletas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Implementação do OEE nas máquinas de laminação a frio

Through a description of the productivity problems experienced by some enterprises, to optimize their respective production lines, results of poor performance or low quality, the following work aims to explain and demonstrate the practical application of the theory of overall equipment effectiveness (OEE) on cold lamination machines in a steel industry . The project, to ensure your goal, is based on structuring a complete planning to increase levels of performance, availability and quality relating to rolling. On completion of the work, will be presented forecasts of future goals for the OEE, to search for continuous improvement and global standards of efficiency, taking into account, the sector the company operates, the history of the laminators, and financial aspects

Impactos causados por vibrações mecânicas em chapas de alumínio no processo de laminação a frio

This paper purpose is to analyze one of the main problems faced by cold rolling industry of the current time, the mechanical vibration. Factors such as strips with high velocity in order to increase the productivity and thickness becoming thinner and thinner cause the vibrations to be present at all times during rolling. These market requirements also drive the industry for technology development and thus bring the challenges that the operation of a new modern equipment and more powerful. The initial purpose is to analyze the forces that cause vibration in a rolling mill type four high with two stands, where is desirable to identify the origins of these vibrational forces to make possible dismiss them or at least control its intensity, in order to prevent damage in the rolling mill and ensure product quality to the customer. For it, will be used instruments to record and store the vibrations that occur during the lamination process. With this data will be able to analyze the characteristics of the vibrations and act at your elimination. At the end of the work is expected to demonstrate how important the critical view of the engineer in the analysis of graphics combined with the calculations of the natural vibration frequency and engagement of key parts of the laminator. With these two tools at hand, will be possible to increase the productivity of the rolling mill and act preventively in maintenance, thereby reducing your downtime and increasing its performance and efficiency

Verificação de pilares metálicos compostos constituídos por perfis formados a frio por meio de programa computacional

In this work, we discuss the procedures adopted for the design of built-up columns (laced and battened columns). Built-up columns are widely used in steel construction generally when the compression forces are relatively low and the column buckling lengths are large. They are commonly used in industrial buildings, for example, as posts for cladding, or as columns supporting a crane girder. Unlike columns with full section, in the case of built-up columns, it is necessary to evaluate the shear stiffness. In fact, the shear strength leads to a significant reduction of the critical load. In the context of this work, the components of the columns (chords, diagonals, posts, etc.) are formed by cold-formed members. In order to systematize and rationalize the verification of the built-up columns, this work aim to develop a computer program based on the standards NBR 14762, NBR 6355 and Eurocode 3, basically the considerations of the part EN 1993-1-1

Efeitos da suplementação de taurina ou flavonóides de cacau associado à achocolatado sobre a composição corporal, metabolismo de carboidratos e proteinas, desempenho fisico, dano muscular e estresse oxidativo em atletas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)