8 research outputs found

    The Ilha Anchieta Quartz Monzonite: the southernmost expression of ca. 500 Ma post-collisional magmatism in the Ribeira Belt

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    The Ilha Anchieta Quartz Monzonite (IAQM) occupies most of the homonymous island in the coast of the state of São Paulo, and is intrusive into foliated rocks of the ~565 Ma Ubatuba Charnockite. The main petrographic variety is a porphyritic biotite-hornblende quartz monzonite with 2-4 cm tabular microcline megacrysts set in a medium-grained groundmass and magmatic foliation. Outcrop-scale structures indicate cumulative processes (modal and grain-size magmatic banding) and interaction with basic magmas (mafic microgranular enclaves). Lithogeochemical data indicates that the main variety is intermediate to acid (S1O2 = 63-67%), alkali-calcic, metaluminous and magnesian (mg# ~30), showing moderate Sr (300-400 ppm) and Ba (~1500 ppm) contents and relatively high HFSE (Nb = 40 ppm; Zr = 550-700 ppm). The older charnockites are more silicic (S1O2 = 71-78%), ferroan(mg# = 12-16), and have very low Sr (13-80 ppm) contents, resulting in Ba/Sr ratios remarkably higher than the IAQM (10 versus 4). LA-MC-ICPMS U-Pb zircon dating of the IAQM yielded 499.7 ± 5.9 Ma. This is the youngest magmatic age identified so far in the crystalline basement of the state of São Paulo, and indicates that the pluton is the southernmost expression of the post-collisional "G5" magmatism in the Ribeira Belt

    Dynamic Model of a Transcritical CO2 Heat Pump for Residential Water Heating

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    This paper presents a distributed mathematical model for a carbon dioxide direct expansion solar-assisted heat pump used to heat bath water. The main components are a gas cooler, a needle valve, an evaporator/collector, and a compressor. To develop the heat exchange models, mass, energy, and momentum balances were used. The model was validated for transient as well as steady state conditions using experimental data. A reasonably good agreement was observed between the predicted temperatures and experimental data. The simulations showed that the time step required to demonstrate the behavior of the heat pump in the transient regime is greater than the time step required for the steady state. The results obtained with the mathematical model revealed that a reduction in the water mass flow rate results in an increase in the water outlet temperature. In addition, when the carbon dioxide mass flow rate is reduced, the compressor inlet and outlet temperatures increase as well as the water outlet temperature

    Clinical-epidemiological evaluation of respiratory syncytial virus infection in children attended in a public hospital in midwestern Brazil

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    Respiratory syncytial virus (RSV) is responsible for annual respiratory infection outbreaks in infants and young children worldwide, frequently causing bronchiolitis and pneumonia. We evaluated clinical and epidemiological features of acute respiratory infections (ARIs) caused by respiratory syncytial virus (RSV) in children less than five years old. Nasopharyngeal aspirate samples from children with ARI symptoms, attended at the 'Hospital das Clínicas' - Federal University of Uberlândia, MG, Brazil, were collected and tested for RSV by the immunofluorescence assay (IFA). Patients' clinical and epidemiological data were also obtained. From April 2000 to June 2003, 317 nasopharyngeal samples were collected from children less than 54 months old. Seventy-six samples (24.0%) were positive for RSV, with 53% (40/76) obtained from male patients. Hospitalization occurred in 50% (38/76) of the cases, with an average period of 10.6 days, in most cases (87%, 33/38) occurring in children less than 12 months of age. Although an association between this age group and the presentation of more severe clinical symptoms was observed, such as bronchiolitis in 51% (27/53) of the patients and pneumonia in 19% (10/53), no patients died. RSV was found from February to August, with the highest incidence in May. Conclusions: RSV is an important agent that causes ARIs; the clinical manifestations varied from mild to severe and patients frequently required hospitalization; RSV mostly affected children less than one year old

    Clinical-epidemiological evaluation of respiratory syncytial virus infection in children attended in a public hospital in midwestern Brazil

    No full text
    Respiratory syncytial virus (RSV) is responsible for annual respiratory infection outbreaks in infants and young children worldwide, frequently causing bronchiolitis and pneumonia. We evaluated clinical and epidemiological features of acute respiratory infections (ARIs) caused by respiratory syncytial virus (RSV) in children less than five years old. Nasopharyngeal aspirate samples from children with ARI symptoms, attended at the 'Hospital das Clínicas' - Federal University of Uberlândia, MG, Brazil, were collected and tested for RSV by the immunofluorescence assay (IFA). Patients' clinical and epidemiological data were also obtained. From April 2000 to June 2003, 317 nasopharyngeal samples were collected from children less than 54 months old. Seventy-six samples (24.0%) were positive for RSV, with 53% (40/76) obtained from male patients. Hospitalization occurred in 50% (38/76) of the cases, with an average period of 10.6 days, in most cases (87%, 33/38) occurring in children less than 12 months of age. Although an association between this age group and the presentation of more severe clinical symptoms was observed, such as bronchiolitis in 51% (27/53) of the patients and pneumonia in 19% (10/53), no patients died. RSV was found from February to August, with the highest incidence in May. Conclusions: RSV is an important agent that causes ARIs; the clinical manifestations varied from mild to severe and patients frequently required hospitalization; RSV mostly affected children less than one year old
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