Processamento e caracterização de compósito fibra de sisal/resina epóxi via RTM

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de nanocompósito utilizando diferentes fontes de celulose como reforço

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

O leitor na reportagem de revista: um estudo das marcas da interação no gênero

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da integridade estrutural em um tubo de aço API 5L X70 através da propagação de trincas por fadiga

Pós-graduação em Engenharia Mecânica - FEG

Percepções sobre trajetórias escolares de alunos do ensino fundamental: os contextos, os tempos e as relações

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

Effect of colloidal silica on the mechanical properties of fiber-cement reinforced with cellulosic fibers

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

Potential of bamboo organosolv pulp as a reinforcing element in fiber-cement materials

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A mixed-integer quadratically-constrained programming model for the distribution system expansion planning

This paper presents a mixed-integer quadratically-constrained programming (MIQCP) model to solve the distribution system expansion planning (DSEP) problem. The DSEP model considers the construction/reinforcement of substations, the construction/reconductoring of circuits, the allocation of fixed capacitors banks and the radial topology modification. As the DSEP problem is a very complex mixed-integer non-linear programming problem, it is convenient to reformulate it like a MIQCP problem; it is demonstrated that the proposed formulation represents the steady-state operation of a radial distribution system. The proposed MIQCP model is a convex formulation, which allows to find the optimal solution using optimization solvers. Test systems of 23 and 54 nodes and one real distribution system of 136 nodes were used to show the efficiency of the proposed model in comparison with other DSEP models available in the specialized literature. (C) 2014 Elsevier Ltd. All rights reserved.

Influence of cellulose nanofibrils on soft and hard segments of polyurethane/cellulose nanocomposites and effect of humidity on their mechanical properties

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

Habilidades sociais e análise do comportamento: compatibilidades e dissensões conceitual-metodológicas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Utilização de reforço geossintético em vias ferroviárias

This report analyses the use of geosynthetics in railways for subgrade reinforcement and separation of the track layers. Cases of instrumented test sections were studied. These test sections were located in Australia (with geocomposite applications), Brazil (with geotextile and geodrid applications) and China (with geotextile and geodrid applications). Railway design methods using geosynthetics applications were analyzed as well. Based on a studied case for implementation of geosynthetics in a German railway, a railway track was simulated with and without the use of geosynthetics, respectively on PLAXIS v.8 and FERROVIA 3.0 softwares. The performance benefits of the geosynthetics applications in railways were, therefore, confirmed, based on the simulation results

Verificação de terceira ordem de estruturas de concreto armado de edíficios

The change in design of a building can occur during its construction process, especially when this change involves greater amount of profit for the building company, as it is the case of adding extra floors. However, there must be an analysis of the structure of the building in order to see if it is possible to increase the number of floors without the need of reinforcement, as this need would result in higher costs for the building company. This graduation report presents this analysis by using the methods of third order verification of reinforced concrete structures

Desenvolvimento e caracterização de compósitos de fibras naturais modificadas e híbridos: fibras da coroa do abacaxi/polipropileno e fibras da coroa do abacaxi/fibras de vidro/polipropileno

The concern with the environment preservation has done with that researchers as well as industries invest in the search for materials that come from renewable sources. Natural fibers, because they are ecologically correct and have low cost, have been studied as a possible substitute, even if partial, of synthetic fibers in the development of polymeric composites. In this context, the hybrid composites (natural/synthetic) increase considerably the range of application of natural composites. The auto industry, in its constant quest for good mechanical properties materials which are developed with sustainability, has in composites with hybrid reinforcement a very viable alternative. In the present work, the nature Crown pineapple fibers and nature Crown pineapple fibers treated with alkaline solution were studied in order to evaluate the influence of chemical treatment in its properties. For this techniques were used x-ray diffractometry, Thermogravimetry and Infrared Spectroscopy (FTIR). Composites have been developed using polypropylene, reinforced with pineapple fibers and pineapple fibers hybrids/glass fibres, both with levels of 5 and 10%. These composites were analyzed by Thermogravimetry techniques and tested by traction. The realization of this work indicated that although the chemical treatment did not affect the thermal stability of the fibers, caused an increase in crystallinity index fibers and decreased its hydrophilic. The tests performed on composite indicated that the composites process was suitable because it provided good dispersion of the polymer matrix. The addition of natural fibers from the pineapple's Crown, in a proportion of 10%, provided the greatest increase in modulus of elasticity (27%) when compared to the pure polymer

Estudo da eficiência de reforços estruturais em vigas de concreto armado com o uso de chapas de aço coladas com resina epóxi: uma análise qualitativa

In civil engineering, a structure is the whole sustainment of a construction and, thus, it is important that it remains intact throughout its lifetime. An engineering construction must last for decades without losing its functionality. However its purpose may be altered and several times the original structure does not meet the new needs of use. Still, in new buildings, the functionality is altered due to possible flaws in execution and the structure, invariably does not reach the desired solicitation needs. In cases like this, the commonly adopted solutions are, basically, the demolishment followed by the reconstruction of the desired mold or the structural reinforcement. This second option, for long years, has not been put to practice due to certain factors such as the high costs for its implantation, use of inadequate reinforcement execution techniques, and the culture of people involved in the area regarding its use and, in this case, the option would always be the reconstruction. Thoughtout the years, some techniques were developed to allow the execution of structural reinforcements with low costs and in efficient ways. An interesting, fast, efficient and economical technique is the structural reinforcement through metal sheets put together with epoxy resin that can be applied in beams, slabs and pillars. In the present work the different behavior of beams reinforced with this technique. Steel is a very recommended material for these reinforcements due to its characteristics related to traction, compression and the effectiveness of the technique related to its cost. For the attachment the epoxy resin is recommended, since it allows the joining of two materials, in this case, steel and concrete. The efficiency of this union is so considerably high that it rarely produces any flaws in adherence and, normally, when it happens it is due to problems in the execution process, not in the union of materials

Estudo comparativo de dois tipos de painéis de MDP: com adição de papel impregnado e lâminas de bambu

This work is the production of two types of particle boards reconstructed MDP (Medium Density Particleboard), the first with the addition, in the inner layer of particles of impregnated paper, the ratios of 0%, 1%, 5% and 20 %. In the second type of panel MDP was inserted with blades of bamboo species Dendrocalumus giganteus as coatings and structural reinforcement. The MDP panel, used as a basis for both cases has the composition of three layers, two external particles with smaller particle size and an inner layer composed of particles of larger particle sizes. Assays were performed based on physical and mechanical NBR 14.810/2006 for the determination of the board density, thickness swelling, water absorption, moisture content, bending, tension parallel and perpendicular, and testing of particle sizes of the particles did not exists in standard references. The results were analyzed and compared the results of the commercial boards made from 100% eucalyptus, based on the limits specified by the ABNT NBR 14.810/2006. The values of the tests showed similar results indicating normative specifications in a positive way, the possibility of production of MDP with the use of waste paper impregnated. As for the panel with bamboo blades, the tests showed a mechanical performance far superior to MDP market, explaining the study and possible implementation of the bamboo for use where the MDP will suffer greater mechanical stress, such as doors, tops and benches tables