X-ray fluorescence with synchrotron radiation total reflection was used to analyze the atmospheric particulate collected in Campinas, SP, Brazil, in fine and coarse fractions, using a stacked filter unit. After treatment with acid solution and pipetting on to Perspex disks, the samples were measured at the x-ray fluorescence beamline at the National Synchrotron Light Laboratory (LNLS), Campinas, using a polychromatic beam for sample excitation. The detection limits obtained ranged from 0.3 to 8.9 ng m −3 for the majority of the elements. The data obtained were treated using analysis receptor models of the principal components, then absolute principal component analysis was applied to obtain the contribution of each source to the total of both particulate fractions. Four sources were identified for the fine fraction for autumn/winter and summer periods: (1) soil dust (22 and 29%); (2) industry (26 and 23%); (3) sulfate (23 and 20%); (4) motor vehicle (22 and 20%); and 7% and 8% non-explained, in the autumn/winter and summer periods, respectively. In coarse fraction analysis, two sources were identified for the autumn/winter and summer periods and with similar rates for source contribution. The obtained sources were: (1) soil dust (77 and 78%); (2) industry (18 and 16%); and non-explained rates of 5 and 6%, in the autumn/winter and summer periods, respectively.

An X-ray tube with a Mo target and Zr filter, operated at 45 kV/20 mA, was used to excite samples (5 microL deposited on a quartz support) and the total reflection angle condition was obtained with a double reflector module built with two 10-cm-long 7-mm-thick quartz crystals placed 50 microns apart. A high-resolution spectrometer based on a Si(Li) detector coupled to a multichannel analyzer was used for X-ray detection and the spectra were interpreted with the AXIL software. The system was calibrated with standard chemical solutions containing Cr, Fe, Cu, Zn, and Pb, and Y was used as an internal standard to correct eventual geometric errors and high-voltage instabilities of the X-ray generator. The limits of detection were 19, 9, 5, and 4 ng/mL for Cr, Fe, Cu, and Zn, respectively, analyzed through characteristic K alpha X-rays, and 7 ng/mL for Pb, through L alpha X-rays, considering 50 microL samples deposited and dried on a quartz support, to be excited/detected for 1000 s.

Abstract. In this work Total Reflection X-Ray Fluorescence Analysis with excitation by Synchrotron Radiation (SR-TXRF) has been used for rainwater trace element analysis. The samples were collected in four different sites at Campinas City, SP, Brazil. Rainwater samples of 10 jal were added to Perspex reflector disks, dried under vacuum and analyzed for 100 s measuring time For the calibration system standard solutions with gallium as internal standard were prepared.. The detection limits obtained for K-shell lines varied from 29 ng.ml" 1 for sulfur to 1.3 ng.ml" 1 for zinc and copper, while for L-shell the values were 4.5 ng.ml" 1 for mercury and 7.0 ng.ml" 1 for lead.

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Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures consist of roof openings that work as air captors or extractors depending on their location in relation to the prevailing wind directions. The hospitals of the Sarah Network, designed by the Brazilian architect João Filgueiras Lima, Lelé, are worldwide known for using these elements to improve natural ventilation. This paper analyses the natural ventilation performance of sheds for air collecting and extracting in two Sarah hospitals located in the cities of Salvador and Rio de Janeiro. In each building, the sheds were analyzed for air extracting and collecting. The analyses were carried out by reduced physical models in an atmospheric boundary layer wind tunnel. The wind velocity was measured at external and internal points of the buildings, using hot-wire anemometers. The results show that the wards in Rio de Janeiro hospital are 17% more ventilated than the ones in the Salvador hospital. However, this difference occurs not only because of the collecting sheds but also because of set of openings and the configuration of the covering in hospitals in Rio de Janeiro.

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