999 resultados para Coeficiente de difusão aparente
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Nowadays, bamboo is being studied because of their strength properties according with their specific mass and speed of growth, which makes it an important alternative as a new resource that will help reduce pressure on forests and helpping them favoring the minimization of uncontrolled deforestation in many regions of Brazil. This study aimed, in general, to analyze physical and mechanical properties of the material with the divulgation of its potential for industrial application. To do so, in this research were determined in relation to the physical properties, moisture content, dimensional stability and the apparent densities and the mechanics and basic, just a tension parallel to grain, in order to observe the interference of various kinds of treatments (chemical, thermal and natural) on the strength and modulus of elasticity in this request. The species used was the Guadua angustifolia, a species native of Brazil. All tests were performed at Universidade Estadual Paulista - Campus Experimental Itapeva in the laboratory of Materials Properties. The methodology used for testing of moisture, density and tension parallel to grain were based on NBR 7190/1997 for the wood, and dimensional stability tests were based on much the same as in COPANT 462/1972 (South American) . The preservative treatments conducted followed the recommendation of each manufacturer. The values obtained in tests of physical properties were satisfactory especially with respect to density and dimensional stability analyzed by the coefficient of anisotropy, showed that, compared to wood, excellent quality for the shrinkage test, obtaining a coefficient of 1.2. With respect to parallel tensile tests to fibre results showed, in most cases, that test specimens with the presence of us have lower values of resistance and modulus of elasticity when compared with those without us. In the treatment of thermal-treatment there was an apparent treatment there was an apparent increase in...
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This study investigated the effect of slope and antecedent soil moisture on the water depth stored and percolated on extensive green roofs built in pilot scale. For this purpose, slopes of 10, 20 and 30% were investigated. Moisture was measured before and after each test to determine the differential moisture (ΔU). A rainfall simulator was designed and tested; the best arrangement presents a Christiansen Uniformity Coefficient of 56%. The results yielded that the slopes of 10% presented the highest values of water depth stored (59,88%), water depth percolated (77,15%), the slope of 30% presented the highest water depth drained (48,22%.) and there was no correlation between slope, water depth stored, water depth percolated and ΔU. It was verified the effect of dilution on the modules i10% between water depth percolated and apparent color (0.71%) in i20% between water depth drained and apparent color (-0.748%) and in the module i30% between water depth drained and turbidity (-0.76%) and water depth drained and apparent color (-0.93%). In i10% there was high correlation between pH and water depth percolated (0.94%) and between water depth drained and pH (0.71%). The data indicate that the module i10% had a greater reduction of runoff
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This paper proposes to assess the lability of complexes of uranium in soil using the technique of Diffusion in Thin Films by concentration gradients (DGT) in the vicinity the Osamu Utsumi mine, located in the municipality of Caldas - MG. The technique is based on the 1ª Fick Law, where metal complexes diffuse through a gel, which in turn is adsorbed on a resin. The metals adsorbed are recovered by an analytical technique and quantified by optical emission spectrometer with plasma inductively coupled (ICP-OES) or mass spectrometry with inductively coupled plasma (ICP-MS)
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The DGT technique has been used to determine and better understand the dynamics and bioavailability of metals in the sea near to marine outfalls. In this work, the DGT was assessed for the determination of Cd, Pb, Cu, Zn and Ni in marine water samples from Potiguar Basin in its conventional aspect (binding agent, Chelex-100 and diffusive agent: Diffusive polyacrylamide gel (D) and restrictive (R)) and determination of Pb and Cd through its alternative aspect (binding agent: Saccharomyces cerevisiae immobilized in agarose gels and diffusive agent: 3MM Chromatography Paper). The deployment curves for long periods of immersion in the sample, showed a good linear correlation for the conventional aspect to Zn (D: R²=0.9586, R: R²=0.9444), Ni (D: R²=0.9789, R: R²=0.9286) and Cu (D: R²=0.764, R: R²=0.8143), and alternative to Pb (R²=0.9228) and Cd (R²=0.9673). The results of the organic and inorganic composition analysis in conventional aspect, showed that for every element there is no significant fraction of organic compounds in the sample. In addition, considering the alternative aspect, the comparison of obtained and expected masses suggests that some of the Pb is not labile and that the main retention mechanism of Pb for S. Cerevisiae occurs through ion exchange
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O fluconazol é um antifúngico de amplo espectro indicado para o tratamento de infecções fúngicas sistêmicas e superficiais. A determinação da potência dos antimicrobianos é importante no controle e na garantia da qualidade das preparações farmacêuticas e faz-se necessário o desenvolvimento de procedimentos práticos e econômicos que possam ser validados e aplicados no doseamento desses fármacos. Dentre os ensaios microbiológicos, os mais comumente empregados são o de difusão em ágar e o turbidimétrico. O objetivo deste trabalho foi desenvolver e validar métodos microbiológicos para determinação da potência do fluconazol cápsulas. O método de difusão em ágar foi desenvolvido empregando ágar Sabouraud e Candida albicans ATCC 64548 como micro-organismo teste. Foi utilizado o delineamento 3 x 3, segundo preconiza a Farmacopeia Brasileira (2010). A validação do método demonstrou linearidade entre o diâmetro dos halos de inibição e o logaritmo da concentração numa faixa de 25,0 a 100,0 µg/mL. Os resultados foram precisos, com desvio padrão relativo igual a 6,15%, e exatos, com intervalo de tolerância de 97,30%, dentro dos limites permitidos. O método foi aplicado ainda em estudos de estabilidade, nas condições de estresse calor úmido, em câmara climática a 40 ºC e 75% de umidade relativa por 90 dias; calor seco, em estufa a 60 ºC por 66 dias e fotodegradação, em câmara espelhada com luz UVC por 66 e 180 dias. Os valores de teor médio calculados foram de 30,27% para calor úmido; 27,72% para calor seco; 33,29% para fotodegradação durante 66 dias e 25,00% para fotodegradação durante 180 dias
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It is known that there is a wide variety of bioavailable trace metals in aquatic systems, and its determination is fundamental to predict impacts to organisms in these environments. However, the determination of the total concentration of chemicals in aquatic systems, despite its importance, does not provide necessary information for decision making or even may lead to misinterpretation of the procedures and potential risks to the system in question. This study aimed to use the technique of diffusion in thin films by concentration gradients (DGT) to evaluate the anion exchange membrane Whatman DE 81 as binder alternative in determining Cr (VI). Experiments were carried out to determine the diffusion coefficients for the material used diffusion (agarose gel). The behaviors of the binders were analyzed before the main variables of the systems, immersion time, pH and ionic strength. Then was made the assessment of potential interferences, to finally proceed with testing using actual samples in the laboratory and in situ
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Worldwide environmental degradation is an undesirable byproduct resulting from the increasing demand for natural resources. Water sources are suffering intense contamination since they usually receive a huge amount of domestic and industrial effluents - which are mostly wasted without proper treatment - inserting a large number of pollutants in the environment, heavy metals included. Mercury holds great toxicological importance because, under some physicochemical conditions in a water environment, Hg (II) ion turns into methylated compounds stemming from this element, such as methylmercury CH3Hg, which is highly toxic for the aquatic community in which bioaccumulation occurs. Nowadays passive sampling techniques are being developed to enable the analytical procedures which are applied in environmental monitoring. Diffusive gradients in thin-films technique (DGT) has been proven an interesting tool for the determination of labile metal species due to its in situ application. The DGT technique consists of a piston-like device on which the following series of agents is disposed: a binding agent (conventionally Chelex 100 resin), a diffusive agent, usually a polyacrylamide gel, and a membrane filter. Nevertheless, the agents conventinally used for this technique don't usually show satisfactory results in mercury sampling. The main goal of this study was to evaluate the phosphate-treated cellulose membrane (Whatman P 81), an alternative material, as binding agent in the DGT to determine labile mercury fractions in aquatic systems. In this context, we conducted a study of the behavior of this material in relation with system variables, pH and ionic strength. Afterwards we performed immersions of the DGT devices in real and enriched samples and in situ aiming the determination of mercury
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Zootecnia - FCAV
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Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC
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The ideas related to the psychoanalysis of children began to be disseminated in Brazil in the 1920’s, by professionals connected to medicine and education. Therefore, the present article aims showing the contributions of Julius Pires PortoCarrero in the introduction of ideas referred to psychoanalysis of children in Brazil from 1920 to 1930, focusing on education. Through bibliographic research all of the author´s work that used psychoanalytic ideas to discuss themes related to education were identified. The conclusions indicate that, in agreement with new educational proposals emerged in the country in the 1920s, the author devoted himself to spread psychoanalytic concepts among educators, assuming that a better understanding of the child based on psychoanalysis could support its development and also the learning process. Besides conferring social legitimacy to psychoanalysis, this initiative has enabled the arising of a more comprehensive practice in child psychoanalysis.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Engenharia Civil e Ambiental - FEB