971 resultados para vapor phase transport
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FEMS Yeast Research, Vol. 9, nº 4
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Thesis to obtain the Master of Science Degree in Computer Science and Engineering
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O transporte de cargas é uma tarefa comum para crianças, adolescentes e adultos, pela necessidade de transferência diária de objetos pessoais, livros e artigos de papelaria para os locais de trabalho ou escolas. Diversos autores apontam que o peso carregado durante transporte de material é o principal responsável pelo aparecimento de dor lombar. Deste modo é importante o constante estudo da temática para a definição recomendações e limites. O presente estudo teve como principais objetivos a caraterização da problemática associada à utilização de mochilas e a determinação do Peso Máximo Aceitável (PMA) e do Índice de Esforço Percebido (IEP) para a tarefa de transporte de mochilas, através da abordagem psicofísica. O estudo foi desenvolvido com estudantes do 7º, 8º e 9º ano de escolaridade e, foi dividido em duas fases. Na 1ª fase foram aplicados questionários para a análise da problemática associada à utilização de diferentes tipos de mochilas escolares. Nesta fase, foram incluídos aspetos associados à identificação do tipo de mochila mais utilizada, as rotinas e hábitos dos estudantes e as características da mochila utilizada. Verificou-se que os estudantes utilizam, maioritariamente, a mochila de duas alças para transporte de material escolar. Posteriormente foram efetuadas medições de peso da mochila, altura e peso aos 131 estudantes que constituíram a amostra da 1º fase. O principal objetivo deste ponto foi identificar o tipo de mochila habitualmente utilizada pelos estudantes assim como, o peso transportado nas mochilas. Na 2ª fase foi efetuado um estudo para a determinação do PMA e do IEP, através da abordagem psicofísica, para a tarefa de transporte de mochila, considerando-se uma amostra constituída por 10 estudantes. Para este estudo, apenas foi considerada a mochila mais frequentemente utilizada, identificada na 1º fase. A tarefa consistiu no transporte da mochila nos dois ombros e com as alças devidamente ajustadas ao corpo, num percurso pré-definido, de acordo com o procedimento experimental. Os resultados indicaram que nem todos os estudantes transportam mochilas com pesos dentro das recomendações da Organização Mundial de Saúde. O PMA determinado pelos estudantes foi de 6.8 kg para a mochila de duas alças e a região dos ombros foi identificada durante todo o estudo como sendo a que apresentava maior intensidade de dor durante o transporte da mochila.
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Eosinophil dynamics, in bone marrow, blood and peritoneal exudate, of resistant C57B1/6 (C57) and susceptible A/Snell (A/Sn) mice was comparatively studied during the acute phase of infection by Trypanosoma cruzi Y strain. A decline was observed in bone marrow eosinophil levels in A/Sn, but not in C57 mice, soon after infection, those of the former remaining significantly below those of the latter up to the 4th day of infection. Bone marrow eosinophil levels of C57 mice declined subsequently to levels comparable to those of A/Sn mice, the number of these cells in this compartment remaining 50% those of non infected controls, in both strains, up to the end of the experiment on the 14th day of infection. The fluctuations in eosinophil levels in blood and peritoneal space were similar in both mice strains studied. Concomitantly with depletion of eosinophils in the marrow, depletion in blood and a marked rise of these cells in the peritoneal space, initial site of infection, occurred in both strains. The difference in eosinophil bone marrow levels, between C57 and A/Sn mice, observed in the first four days of infection, suggests a higher eosinopoiesis capacity of the former in this period, which might contribute to their higher resistance to T. cruzi infection.
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In the experimental schistosomiasis mansoni glucocorticoids cause a reduction in the worm burden when administered in the week of infection or, the longest, at the next week. In order to determinate the probable(s) site(s) of reduction of the worm burden, mice were infected with cercariae of LE strain of S. mansoni and dexamethasone was administered daily (50 mg/kg, subcutaneously) starting 1 hour before infection until the eighth day. Mice were sacrificed daily starting on the third day after infection until the ninth day, and schistosomula from lungs were collected. Six weeks after infection, the remaining mice were sacrificed and perfused for adult worm recovery. Analysis of the results showed that the non-treated mice presented larger numbers of lung larvae than the treated ones, and this difference was also found later in the worm burden in the portal system. This difference may reflect the early death of larvae in treated animals, before or after reaching the lungs.
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A dot enzyme-linked immunosorbent assay (DOT-ELISA) was developed to detect specific antibodies in cerebrospinal fluid (CSF) for human neurocysticercosis immunodiagnosis, with Cysticercus cellulosae antigen dotted on a new solid-phase. This was represented by sheets of a synthetic polyester fabric impregnated with a polymerized resin (N-methylol-acrylamide). A very stable preparation was thus obtained, the antigen being covalently bound by cross-linking with free N-methylol groups on the resin. Since robust, no special care was necessary for handling the solid-phase. The test could be performed at room-temperature. From 30 CSF samples assayed, 14 were positive, from a group of 15 cases of neurocysticercosis, with titers from 1 to 128; 15 other samples, from normals or other neurological diseases, were all negative. Test characteristics seem to indicate it as adequate for epidemiological surveys. A more detailed study on sensitivity, specificity, reproducibility and the use in serum samples is being conducted.
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Recently had been discovery, in the area of the construction of the Carla Sacramento Athletics Stadium at Cruz de Pau (Seixal), a set of stopes and wells with characteristics of ancient Roman mining activities. The old mining works are incised in pliocene sandy formations with conglomeratic facies, where four preliminary samples were collected in a coarser level with subrounded pebbles. The heavy minerais of those samples were studied in accordance with the Heavy Mineral Concentrate Laboratory of the IGM. The previously mentioned facies has interesting gold percentages and the presence of grey (nodular) and classic monazite, xenotime, cassiterite, spinels s.l., ilmenite and rutile. The morphology of the gold grains as well as the heavy minerals shows two phases of transport; an initial fluvial phase and a secondary aeolian phase influenced their concentracion. The high percentage of toroid grains showing evidence of wind ablation, suggests that this was the main factor for reconcentration of the gold. The amount of gold particles obtained in the concentrates is considerable and in one sample, a grade of 3.2 ppm was calculated. The samples also have been analysed for Au + 34 elements by INAA and ICP-MS, the results of which show similar grades as previously obtained.
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The prediction of the time and the efficiency of the remediation of contaminated soils using soil vapor extraction remain a difficult challenge to the scientific community and consultants. This work reports the development of multiple linear regression and artificial neural network models to predict the remediation time and efficiency of soil vapor extractions performed in soils contaminated separately with benzene, toluene, ethylbenzene, xylene, trichloroethylene, and perchloroethylene. The results demonstrated that the artificial neural network approach presents better performances when compared with multiple linear regression models. The artificial neural network model allowed an accurate prediction of remediation time and efficiency based on only soil and pollutants characteristics, and consequently allowing a simple and quick previous evaluation of the process viability.
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Siderophore production by Bacillus megaterium was detected, in an iron-deficient culture medium, during the exponential growth phase, prior to the sporulation, in the presence of glucose; these results suggested that the onset of siderophore production did not require glucose depletion and was not related with the sporulation. The siderophore production by B. megaterium was affected by the carbon source used. The growth on glycerol promoted the very high siderophore production (1,182 μmol g−1 dry weight biomass); the opposite effect was observed in the presence of mannose (251 μmol g−1 dry weight biomass). The growth in the presence of fructose, galactose, glucose, lactose, maltose or sucrose, originated similar concentrations of siderophore (546–842 μmol g−1 dry weight biomass). Aeration had a positive effect on the production of siderophore. Incubation of B. megaterium under static conditions delayed and reduced the growth and the production of siderophore, compared with the incubation in stirred conditions.
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In this paper the history of 115 recruits that had bathed simultaneously in streams contaminated with Schistosoma mansoni, during military maneuvers, is reported. Thirty four of the infected patients presented the initial phase of the infection diagnosed through epidemiologic, clinical and laboratorial parameters. Three out of the 34 patients did not reveal the clinical picture of the infection, thus being considered representatives of the non-apparent form of the disease. Differences between the intensity of blood eosinophilia, the area of immediate cutaneous reaction and the number of Schistosoma eggs eliminated in the stools proved not to be statistically significant (p>0.05) when the non-apparent and acute cases of schistosomiasis were compared. These cases actually may be considered evidences of the non-apparent form hitherto merely taken for granted in the literature.
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We introduce a simple model for a biaxial nematic liquid crystal. This consists of hard spheroids that can switch shape between prolate (rodlike) and oblate (platelike) subject to an energy penalty Δε. The spheroids are approximated as hard Gaussian overlap particles and are treated at the level of Onsager's second-virial description. We use both bifurcation analysis and a numerical minimization of the free energy to show that, for additive particle shapes, (i) there is no stable biaxial phase even for Δε=0 (although there is a metastable biaxial phase in the same density range as the stable uniaxial phase) and (ii) the isotropic-to-nematic transition is into either one of two degenerate uniaxial phases, rod rich or plate rich. We confirm that even a small amount of shape nonadditivity may stabilize the biaxial nematic phase.
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Aiming at demonstrating a decrease of acquired immunity after chemotherapeutic cure, a group of mice was infected with 25 Schistosoma mansoni cercariae (LE strain). A part of these animals was treated with 400 mg/kg oxamniquine, at 120 days after infection. Challenge infections were carried out at 45, 90 and 170-day-intervals after treatment (185, 210 and 290 days after primoinfection, respectively). Recovery of worms at 20 days after reinfections showed that a residual immunity remains up to 90 days after treatment, and disappears at 170 days after cure. Using the ELISA method, it was possible to detect a decrease of antibody levels (total IgG) in the treated group, when antigens from different evolutive stages of S. mansoni were used. The epidemiological implications of the present results, and the possible mechanisms involved in the decrease of acquired immunity after treatment are discussed.
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33rd IAHR Congress: Water Engineering for a Sustainable Environment
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River Flow 2010