933 resultados para Autogenous And Semi-autogenous Milling


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Pós-graduação em Engenharia Mecânica - FEIS

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Novel brominated amorphous hydrogenated carbon (a-C:H:Br) films were produced by the plasma polymerization of acetylene-bromoform mixtures. The main parameter of interest was the degree of bromination, which depends on the partial pressure of bromoform in the plasma feed, expressed as a percentage of the total pressure, R-B. When bromoform is present in the feed, deposition rates of up to about 110 nm min(-1) may be obtained. The structure and composition of the films were characterized by Transmission Infrared Reflection Absorption Spectroscopy (IRRAS) and X-ray Photo-electron Spectroscopy (XPS). The latter revealed that films with atomic ratios Br:C of up to 0.58 may be produced. Surface contact angles, measured using goniometry, could be increased from similar to 63 degrees (for an unbrominated film) to similar to 90 degrees for R-B of 60 to 80%. Film surface roughness, measured using a profilometer, does not depend strongly on R-B. Optical properties the refractive index, n, absorption coefficient, alpha(E), where E is the photon energy, and the optical gap, E-g, were determined from film thicknesses and data obtained by Transmission Ultraviolet-Visible Near Infrared Spectroscopy (UVS). Control of n was possible via selection of R-B. The measured optical gap increases with increasing F-BC, the atomic ratio of Br to C in the film, and semi-empirical modeling accounts for this tendency. A typical hardness of the brominated films, determined via nano-indentation, was similar to 0.5 GPa. (C), 2013 Elsevier B.V. All rights reserved.

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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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Fibers are non-digestible materials by human organism, and they are insoluble in specific conditions. The corn fiber has been used as an alternative to enrich the food products for human consumption, in order to add nutritious value to this co-product. This study aimed at determining the chemical and fractions components of corn fiber, extracted by semi-wet milling in laboratory (LabF), and by semi-humid milling in industrial process (IndF); and microbiological analyses were perform in the last fraction. The fiber composition differed significantly among these two products as to moisture, ash, lipids, proteins, insoluble dietary fiber, neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose and lignin contents. The sample IndF showed microbiological parameters in compliance with the specifications for consumption. The investigated corn fiber may effectively contribute to increase the fiber intake in the diet. As the industrially processed fiber (IndF) showed compliant microbiological parameters with the specifications for food, this component might be incorporated into the food products formulation.

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To quantify fibrin degradation products after topical and subconjunctival administration of recombinant tissue plasminogen activator in rabbits. Methods: Fibrin formation was induced in the anterior chamber in 25 rabbits. Subsequently, five rabbits received an injection of r-TPA (positive control) in the anterior chamber, another 10 received a subconjunctival injection of r-TPA, and the remaining 10 received instillations of topical r-TPA. Afterwards, samples of aqueous humor were collected and semi-quantitative analysis of fibrin degradation products (FDP) was performed. Results: No statistical differences were noted between the treatment and control groups at any time point. Fibrin degradation products semi-quantification showed statistical improvement in the control group and the subconjunctival group. Conclusion: Fibrin degradation products were observed in the anterior chamber after subconjunctival administration of r-TPA. However, it was probably not sufficient to cause fibrin degradation. Topical r-TPA did not effectively absorb anterior chamber fibrin.

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

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

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We studied the diet composition and overlap of Scarlet Ibises (Eudocimus ruber) and Little Blue Herons (Egretta caerulea in a mangrove swamp in southeast Brazil during the 1996-1997 breeding season, which occurs during the rainiest period. Crabs comprised 95% of all prey taken by the ibises and 80% of the prey of the herons, Nevertheless, diet overlap was small (similar to 30%) due to ibises feeding mostly on Uca spp. and Eurythium limosum crabs, which were taken from their burrows; the herons fed on the arboreal and semi-arboreal Aratus Pisonii and Metasesarma rubripes crabs. Divergent hunting strategies of ibises (tactile foragers) and herons visually-oriented predators) explains the diet segregation when preying on an ecologically diverse crab guild, but it is unclear why herons prey rarely on fiddler crabs. Scarlet Ibises bred successfully while feeding oil estuarine organisms living in low salinities in the mangroves, showing that mangroves may be adequate foraging habitats for chick-rearing ibises during periods of low salinity.

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

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Batch combustion of fixed beds of coal, bagasse and blends thereof took place in a pre-heated two-stage electric laboratory furnace, under high-heating rates. The average input fuel/air equivalence ratios were similar for all fuels. The primary and secondary furnace temperatures were varied from 800 degrees C to 1000 degrees C. The effects of fuel blending, combustion staging, and operating furnace temperatures on the emissions from the two fuels were assessed. Furnace effluents were analyzed for carbon dioxide and for products of incomplete combustion (PIC) including CO, volatile and semi-volatile hydrocarbons, as well as particulate matter. Results showed that whereas CO2 was generated during both the observed sequential volatile matter and char combustion phases of the fuels, PICs were only generated during the volatile matter combustion phase. CO2 emissions were the highest from coal, whereas CO and other PIC emissions were the highest from bagasse. Under this particular combustion configuration, combustion of the volatile matter of the blends resulted in lower yields of PIC, than combustion of the volatiles of the neat fuels. Though CO and unburned hydrocarbons from coal as well as from the blends did not exhibit a clear trend with furnace temperature, such emissions from bagasse clearly increased with temperature. The presence of the secondary furnace (afterburner) typically reduced PIC, by promoting further oxidation of the primary furnace effluents. (C) 2012 Elsevier Ltd. All rights reserved.

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This work reports on emissions of unburned hydrocarbon species from batch combustion of fixed beds of coal, sugar-cane bagasse, and blends thereof in a pre-heated two-stage laboratory furnace operated in the temperature range of 800-1000 degrees C. The effects of fuel blending, combustion staging, and operating furnace temperatures on emissions of pollutants were assessed. Furnace effluents were analyzed for products of incomplete combustion (PICs) including CO, volatile and semi-volatile hydrocarbons, and particulate matter, as has been reported in Ref. [1]. Emitted unburned hydrocarbons include traces of potentially health-hazardous Polycyclic Aromatic Hydrocarbons (PAHs), which are the focus of this work. Under the batch combustion conditions implemented herein, PAH were only generated during the volatile combustion phase of the fuels. The most prevalent species were in descending order: naphthalene, acenaphthylene, phenanthrene, fluoranthene, pyrene, dibenzofuran, benzofuran, byphenyl, fluorene, 9H-fluoren-9-one, acephenantrylene, benzo[b] fluoranthene, 1-methyl-naphthalene; 2-methyl-naphthalene, benz[a] anthracene and benzo[a] pyrene. PAH yields were the highest from combustion of neat bagasse. Combustion of the blends resulted in lower yields of PAH, than combustion of either of their neat fuel constituents. Increasing the furnace operating temperature enhanced the PAH emissions from bagasse, but had little effect on those from the coal or from the blends. Flue gas treatment in a secondary-stage furnace, upon with additional air, typically reduced PAH yields by promoting oxidation of the primary-stage furnace effluents. (C) 2011 Elsevier Ltd. All rights reserved.

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Background: Few studies have been conducted on the association between perinatal and early life factors with childhood depression and results are conflicting. Our aim was to estimate the prevalence and perinatal and early life factors associated with symptoms of depression in children aged 7 to 11 years from two Brazilian birth cohorts. Methods: The study was conducted on 1444 children whose data were collected at birth and at school age, in 1994 and 2004/2005 in Ribeirao Preto, where they were aged 10-11 years and in 1997/98 and 2005/06 in Sao Luis, where children were aged 7-9 years. Depressive symptoms were investigated with the Child Depression Inventory (CDI), categorized as yes (score >= 20) and no (score < 20). Adjusted and non-adjusted prevalence ratios (PR) were estimated by Poisson regression with robust estimation of the standard errors. Results: The prevalence of depressive symptoms was 3.9% (95% CI = 2.5-5.4) in Ribeirao Preto and 13.7% (95% CI = 11.0-16.4) in Sao Luis. In the adjusted analysis, in Ribeirao Preto, low birth weight (PR = 3.98; 95% CI = 1.72-9.23), skilled and semi-skilled manual occupation (PR = 5.30; 95% CI = 1.14-24.76) and unskilled manual occupation and unemployment (PR = 6.65; 95% CI = 1.16-38.03) of the household head were risk factors for depressive symptoms. In Sao Luis, maternal schooling of 0-4 years (PR = 2.39; 95% CI = 1.31-4.34) and of 5 to 8 years (PR = 1.80; 95% CI = 1.08-3.01), and paternal age < 20 years (PR = 1.92; 95% CI = 1.02-3.61), were independent risk factors for depressive symptoms. Conclusions: The prevalence of depressive symptoms was much higher in the less developed city, Sao Luis, than in the more developed city, Ribeirao Preto, and than those reported in several international studies. Low socioeconomic level was associated with depressive symptoms in both cohorts. Low paternal age was a risk factor for depressive symptoms in the less developed city, Sao Luis, whereas low birth weight was a risk factor for depressive symptoms in the more developed city, Ribeirao Preto.

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In 2009, the Brazilian Comprehensive Healthcare Policy for Men (PNAISH) was launched in Brazil, seeking to reduce morbidity and mortality in this population group. This article strives to analyze the conceptions that health professionals have about the specific demands and behaviors of the male population served by the healthcare services. The data analyzed are part of a larger research project, the objective of which was to evaluate the initial actions of the implementation of PNAISH. Ethnographic observations in 11 health services and semi-structured interviews were conducted with 21 health professionals. From the perspective of health professionals, the presence of men in the healthcare services is still limited. According to them, it is comprised of two types of clients: workers and the elderly. The male behavior characteristics - haste, objectivity, fear and resistance - and the difficulty faced by health services in receiving this population are the main factors that drive men away from health services. Although the concept of gender is central to PNAISH, it is only triggered by healthcare professionals in order to justify the social standards expected in terms of men's behavior. The attribution of men's behavior to cultural factors ultimately obscures the relations of power that underlie gender relations.