Anatomização de pinos de fibra de vidro: estudo de propriedades mecânicas na interface restauradora adesiva

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

Beneficial effects of fermented vegetal beverages on human gastrointestinal microbial ecosystem in a simulator

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

Componentes produtivos do trigo afetados pela densidade de semeadura e aplicação de regulador vegetal

Improvement on yield potential of plants by crop management is the main research challenge due to the growing of food demand worldwide. The objective of this work was to study physiological and morphological traits and its relationship with yield components and yield of wheat as affected by sowing densities and plant growth regulators. The experimental design was a split-plot design with four replications. The plots were consisted by four sowing densities ( 30, 50 70 and 90 plants m(-1)) and the subplots were consisted by plant growth regulators [control, (IBA+GA+KT), Trinexapac-Ethyl e (IBA+GA+KT) + Trinexapac-Ethyl]. Dry matter accumulation, plant height, source-sink distance, gas exchange and yield were determined. Trinexapac-Ethyl application resulted in decreasing of plant height, source-sink distance and flag leaf length; however, the grain yield was not affected. The number of plants per unit area affected dry matter accumulation. Higher dry matter accumulation showed direct relationship with yield and yield components in lower plant densities.

Consumo, digestibilidade e balanço de nitrogênio de cordeiros alimentados com alto teor de amido ou fibra solúvel em detergente neutro associados ao óleo de girassol

The aim of this study was to evaluate the effect of different carbohydrate sources associated with sunflower oil on intake, digestibility of nutrients and nitrogen balance in diets of lambs. Twenty lambs were used, assigned in a completely randomized design with a 2 x 2 factorial arrangement of treatments with two sources of neutral detergent soluble carbohydrate, starch and neutral detergent soluble fiber, with and without the inclusion of 4.2% sunflower oil. The dry matter intake was not affected by carbohydrate sources and the inclusion of oil. Diets with a high percentage of starch provided higher digestibility of dry matter, starch and ether extract. The different sources of carbohydrates had no interference on digestibility of organic matter, crude protein, neutral detergent soluble fiber, nonfiber carbohydrates, neutral detergent fiber, hemicellulose and acid detergent fiber. The addition of oil in the diets increased the digestibility of ether extract. The combination of 4.2% oil in the diet high in soluble neutral detergent fiber had no influence on the nutrient digestibility, otherwise, the addition of oil at high starch diet caused a significant reduction in the digestibility of organic matter, neutral detergent fiber, hemicellulose and nonfiber carbohydrates. The quantities of nitrogen intake, absorbed and retained, did not differ as sources of carbohydrates and oil inclusion in the diet. The association of 4.2 % sunflower oil to the different sources of carbohydrates in the diet does not affect consumption and nitrogen metabolism in lambs. The addition of 4.2 % oil in the diet with high starch (28% of DM diet) promotes reduction in digestibility of organic matter, of fibrous and nonfibrous carbohydrate in the diet.

Fractografia quantitativa: correlação entre dimensão fractal e tenacidade à fratura em compósitos fibra de carbono/epóxi

The fracture surfaces express the sequence of events of energy release due to crack propagation by linking the relief of the fracture to the loading stresses. This study aims to evaluate the heterogeneity of the critical zone for the advancement of the crack along its entire length in a thermoset composite carbon fiber and epoxy matrix, fractured in DCB testing (Double Cantilever Beam) and ENF (End-Notched Flexure). Investigations were made from image stacks obtained by optical reflection of extended depth from focus reconstruction. The program NIH Image J was used to obtain elevation map and fully focused images of the fracture surface, whose topographies were quantitatively analyzed. The monofractal behavior for DCB samples was assessed as being heterogeneous along the crack front and along the crack for all the conditionings. For the samples fractured in ENF test, there was a strong positive correlation to the natural condition, considering the fibers at 0° for the monofractal dimension and structural dimension (Df and Ds). For fibers at 90° to crack propagation, there was a moderate positive correlation for the textural dimension of natural condition. However, for the samples under ultraviolet condition and those subjected to thermal cycles, there was no correlation between the fractal dimension and fracture toughness in mode II

Biodegradação de óleos derivados do petróleo e de origem vegetal estimulada por biossurfactantes em meio aquoso e monitoramento de sua toxicidade

Não disponível

Amostragem de poluentes gasosos e particulados emitidos pela queima de biomassa vegetal

The use of biomass as an energy source has been increasing in Brazil, with emphasis on the use of wood biomass, such as bark, wood chips and sawdust, that after receiving the appropriate treatment can be used in burners for power generation. However, from this burning are emitted fine particles known as particulate matter and a wide range of toxic organic and inorganic components in the form of gases that contribute greatly to air pollution and global warming, affecting human health, the environment and climate. The objective of this project was the quantification of gaseous and particulate, using and evaluating the equipment DR4000 ( Dataram 4 ) sampling of particulates smaller than 2.5μm and EUROTRON ( Ecoline 4000 ) when sampling gaseous pollutants, emitted from the burning of biomass in real time in the firing burner to a chimney attached biomass . We note that there are no specific rules that establish emission limits for particulate matter with diameter less than 2.5μm that are most harmful to human health and the highest concentrations reached about 800000μg/m3, for smaller diameters. It is noticeable the need for sampling of pollutants especially in industries that use biomass to fuel that could be implanted emission control equipment

Comparação de compósitos obtidos via RTM de resina epóxi e fibra de carbono com e sem descontinuidade nos tecidos

Technology is growing interest in the use of composites, due to the requirement of lighter materials and more resistant, factors essential to meet the project specifications and reduce the operational cost. In the production of high performance structural composites, considering the aerospace criteria, the domestic industry has shown interest in the process of resin transfer molding (RTM) for reproducibility and low cost. This process is suitable for producing components of polymeric composites with relatively simple geometries, consistent thicknesses, high quality finish with no size limitations. The objective of this work was machined carbon steel to make a matched-die tooling for RTM and produce two composite plates of epoxy resin and carbon fiber fabric with and without induced discontinuities, which were compared towards their impregnation with ultrasound, their properties via tensile tests and thermal analysis. In ultrasonic inspection, it was found good impregnation of the preform of both composites. In the thermal analysis it was possible to check the degradation temperature of the composites, the glass transition temperature and it was found that the composites showed no effective cure cycles, but presented good performance in the tensile test when compared with aluminum alloy 7050 T7451 . The results showed that the injection strategy was appropriate since the laminate exhibited a good quality for the proposed application

Cinética de degradação do sistema resina epóxi/fibra de carbono

With the increasing demand for electricity, the retraining of transmission lines is necessary despite environmental restrictions and crossings in densely populated areas to build new transmission and distribution lines. Solution is reuse the existent cables, replacing the old conductor cables for new cables with higher capacity power transmission, and control of sag installed. The increasing demand for electrical power has increased the electric current on the wires and therefore, it must bear out temperatures of 150°C or more, without the risk of the increasing sag beyond the established limits. In the case of long crossings or densely populated areas, sag is due to high weight of the cable on clearance. The cable type determines the weight, sag, height and the towers dimensions, which are the items that most influence the investment of the transmission line. Hence, to reduce both cost of investment and maintenance of the line, the use of a lighter cable can reduce both number and the height of the towers, with financial return on short and long term. Therefore, in order to increase the amount of transmitted energy and reduce the number of built towers and sag, is recommended in the current work substitute the current core material (steel or aluminium) for alternatives alloys or new materials, in this case a composite, which has low density, elevated stiffness (elasticity module), thus apply the pultruded carbon fiber with epoxy resin as matrix systems and perform the study of the kinetics of degradation by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC), according to their respective standards

Processamento do compósito de fibra de capim-sapê / epóxi e avaliação da resistência à flexão “t” de Student

In recent years a great worldwide interest has arisen for the development of new technologies that enable the use of products with less environmental impact. The replacement of synthetic fiber plants is a possibility very important because this fiber is renewable, biodegradable and few cost and cause less environmental impact. Given the above, this work proposes to develop polymeric composites of epoxy resin and study the behavior of these materials. Both, the epoxy resin used as matrix in the manufacture of sapegrass fiber composite, as tree composites formed by: epoxy/unidirectional sapegrass long fiber, 75% epoxy/25% short fiber, by volume, and 80% epoxy/20% short fiber, by volume, were characterized by bending, and the composites produced with short fibers random were inspected by Optical Microscopy and Acoustics Inspection (C-Scan). For the analysis of the sapegrass fiber morphology, composites 75% epoxy/25% short fiber (sheet chopped) and 80% epoxy/20% short fiber images were obtained by optical microscope and the adhesion between polymer/fiber was visualized. As results, the flexural strength of composites epoxy/unidirectional long fibers, 75% epoxy/25% short fiber and 80% epoxy/20% short fiber were 70.36 MPa, 21.26 MPa, 25.07 MPa, respectively. Being that composite showed that the best results was made up of long fibers, because it had a value of higher flexural strength than other composites analyzed

Estudo do efeito da classe de furação na resistência à fadiga em junta alumínio – fibra de carbono

This work performs a comparative study of fatigue life of riveted lap joints involving classes of drilling which adjustment is made with interference or clearance. For this study, representative specimens of this joints were manufactured with four rivets distributed in two rows. In this context, are presented the test matrix, the methodology employed in performing of the tests, the used mathematical modeling, and that methods that are the basis for the latter are described through the theoretical foundation. Next, are present the results obtained in fatigue tests and images of the region of failure of the specimens. Finally, are present some comments and conclusions related to the results obtained

Dinâmica espacial e estrutura fitossociológica do estrato inferior de um trecho da comunidade vegetal às margens do Ribeirão Claro e de seu afluente Jardim Bandeirantes, Rio Claro/SP

O presente trabalho tem como objetivo descrever a estrutura fitossociológica do estrato herbáceo, de diferentes manchas que definem o mosaico da vegetação de um trecho do Ribeirão Claro e seu afluente Jardim Bandeirantes, analisando a diversidade das comunidades no tempo e no espaço, a dominância e a distribuição das espécies, estabelecendo relações com variáveis ambientais edáficas (umidade, pH e teor de matéria orgânica) e microclimáticas (luminosidade, cobertura de dossel e declividade), a fim de estudar a estrutura, composição e os processos sucessionais desta fitocenose. Foram definidas 13 manchas de vegetação como foco de estudo, em cada uma foram dispostas 6 parcelas de 5x5m perfazendo uma extensão de 30 m perpendicularmente ao rio. No interior das parcelas foram levantadas todas as formas de vida vegetais abaixo de 1,5m de altura, aplicando-se um método de avaliação de cobertura (método do toque), onde a amostragem foi realizada em intervalos de 0,5m. Os indivíduos foram amostrados com indicação do seu hábito e classificação taxonômica. As quantificações foram realizadas tanto no período chuvoso quanto no período seco, com a finalidade de entender a dinâmica sazonal dessa comunidade. A comunidade estudada apresentou variação em sua composição e estrutura no que se refere às estações seca e chuvosa. Os parâmetros ambientais analisados mostraram uma heterogeneidade física nas fisionomias descritas, o que pode estar contribuindo para a diferenciação na distribuição das espécies amostradas em cada fisionomia. Com base no inventário realizado, envolvendo a vegetação marginal do trecho estudado do Ribeirão Claro e seu tributário Jardim Bandeirantes, em duas estações distintas, os dados mostraram maiores variações da cobertura herbácea nas fitocenoses em estágios sucessionais mais avançados... (Resumo completo, clicar acesso eletrônico abaixo)

Avaliação do efeito ambiental nas propriedades mecânicas e viscoelásticas de compósitos híbridos de titânio/fibra de carbono/resina epóxi

Hybrid composites combining metal plates and laminates with continuous fiber reinforced polymer, called fiber-metal (CHMF), have been particularly attractive for aerospace applications, due mainly to their high mechanical strength and stiffness associated with low density. These laminates (CHMF) consist of a sandwich structure consisting of layers of polymer composites and metal plates, stacked alternately. This setting allows you to combine the best mechanical performance of polymer composites reinforced with long fibers, to the high toughness of metals. Environmental effects should always be considered in the design of structural components, because these materials in applications are submitted to the effects of moisture in the atmosphere, the large cyclical variations of temperature around 82 ° C to -56 ° C, and high effort mechanical. The specimens of fibermetal composite were prepared at EMBRAER with titanium plates and laminates of carbon fiber/epoxy resin. This study aims to evaluate the effect of different environmental conditions (water immersion, hygrothermal chamber and thermal shock) of laminate hybrid titanium/carbon fiber/epoxy resin. The effects of conditioning were evaluated by interlaminar shear tests - ILSS, tensile, and vibration free

Avaliação da atenuação da toxicidade de lodo de esgoto por associação com resíduo vegetal da indústria sucro-alcooleira

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Produção de carvão vegetal a partir da madeira de Eucalyptus saligna clone SI70 com tres anos e meio de idade

Charcoal is obtained from carbonization, much used in the steel industry for ore reduction, using as raw material the Eucalyptus. The present study aims to verify whether the main Eucalyptus saligna genetically modified produce quality charcoal with only 3.5 years old. The study was done with material collected from three trees, divided into five discs removed at 0, 25 , 50 , 75 and 100 % of the commercial height of the tree. The procedures adopted were based on standards published by ABNT. The results were satisfactory for the parameters: basic wood density with an average of 0.39 ± 0.0082 g / cm ³; volatile materials from coal with an average of 19.35 ± 3.27 %, fixed carbon content of the coal with an average of 75.62 ± 3.40 % and gross calorific value of coal with an average of 4694.43 cal / g, and unsatisfactory results for ash content averaging 5.03 ± 0.23 when compared to the values found in the literature. It was concluded that the studied wood is able to produce charcoal, but the factors of production should be better observed, such as heating time which exerted direct influence on the determination of ash content