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131.
An extensive investigation is in progress aiming at the characterisation of the air particulate composition in Florence. For our investigation, we use the external PIXE-PIGE beam facility of the I.N.F.N. Van de Graaff accelerator at the Physics Department of the Florence University. In order to gather information on both the longer- and shorter-time trends of the aerosol elemental composition, we are analysing both long temporal series (about 1 year) of 24-h Millipore filters collected by the health authorities in 3 different sites, and filters collected simultaneously in two of the above sites for about one month, by two streakers with one-hour resolution, providing size fractionation between particle size smaller than 2.5 µm and from 2.5 µm to 10 µm. The streakers sampling period includes two days during which the Municipality of Florence has banned the circulation of non-catalytic cars, due to the increase of NO2 above the "recommended safety values". We present here the first obtained results for the sampling site located near a heavy traffic road.  相似文献   
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Manual activities of construction workers may induce musculoskeletal disorders. This study on a group of painters aimed to analytically characterize movements of the spinal column by both lumbar motion monitor and television cameras and to determine, using the Occupational Repetitive Actions (OCRA) Index method, the risk exerted by repeated movements of the upper limbs. The main results are: painting with a roller generally exposes workers to a lesser risk for upper limbs than painting with a brush; a roller-stick fixed at the wrong length can lead to stretching of the back at lumbar and cervical levels; to remain within the range of ‘acceptable risk’ (OCRA Index evaluation), a worker should not paint a vertical wall for over 3 h if using a roller and 2.5 h if painting with a brush; and, on average, a painter who paints for 5 h in a day lifts the bucket about 120,140 times.  相似文献   
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The production of bioplastics directly from wheat flour has been demonstrated to be reliable, but scarce knowledge is available on how flour characteristics may affect the performance of thermoplastic films. In this work, we first established the most suitable recipe and process for the production of extruded films and then we used eight single-cultivar wheat flours with different baking technological properties to assess how they affect the mechanical properties of thermoplastic films. The results have shown that flours from soft grain cultivars offered more rigid and deformable films than flours from hard grain cultivars. For similar hardness, the alveographic P/L ratio of the dough was inversely related to rigidity and directly related to deformability of plastic films, while the deformation energy of the dough (W) played a role only for great differences of it. The subsequent fabrication of blends between each of the flours that yielded the best film properties and polycaprolactone (PCL) at different proportions indicated that a wheat flour/PCL ratio (TWF/PCL) of 75/25 offered the most suitable films for further application. Our results are likely to be useful for improving the plasticization of flour, in that selection of wheat flours could be tailored on the properties desired for the bioplastic films.  相似文献   
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Environmental estrogen-like compounds (i.e. xenoestrogens) are a variety of pollutants, ranging from synthetic to natural occurring molecules, that are found in surface and waste waters over a wide range of concentrations. In aquatic environment, the overall estrogenic activity is often due to the presence of a mixture of chemicals and their degraded products which can induce synergistic effects. Current strategies for monitoring estrogen-like chemicals are based on the use of a battery of in vivo and in vitro ecotoxicological tests. In this regard, the aim of the present work was to carry out a bio-monitoring study for testing estrogenicity of the Chienti river (Marche Region, Italy) by using both an E-screen and a vitellogenin (Vtg) induction assay in juvenile goldfish. Three sites were used for analysis, localized at the mouth (sampling point 1), in the middle (sampling point 2) and at the origin (sampling point 3) of Chienti river. For most of the water samples (i.e. samples collected at sampling points 2 and 3), clear estrogenic activity was detected in the E-screen assay suggesting different proliferation activities in function of the collecting site. In contrast, the Vtg ELISA demonstrated that water samples collected from each sampling point were estrogenic. Overall, we showed for the first time that the estrogenic activities in water samples from the Chienti river were significant in both in vivo and in vitro; we also observed a different sensitivity between bioassays.  相似文献   
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ABSTRACT

The issue of fine particle (PM25) exposures and their potential health effects is a focus of scientific research because of the recently promulgated National Ambient Air Quality Standard for PM2 5. Before final implementation, the health and exposure basis for the standard will be reviewed by the U.S. Environmental Protection Agency within the next five years. As part of this process, it is necessary to understand total particle exposure issues and to determine the relative importance of the origin of PM2 5 exposure in various micro-environments. The results presented in this study examine emissions of fine particles from a previously uncharacterized indoor source: the residential vacuum cleaner. Eleven standard vacuum cleaners were tested for the emission rate of fine particles by their individual motors and for their efficiency in collecting laboratory-generated fine particles. An aerosol generator was used to introduce fine potassium chloride (KC1) particles into the vacuum cleaner inlet for the collection efficiency tests. Measurements of the motor emissions, which include carbon, and the KCl aerosol were made using a continuous HIAC/Royco 5130A light-scattering particle detector. All tests were conducted in a metal chamber specifically designed to completely contain the vacuum cleaner and operate it in a stationary position. For the tested vacuum cleaners, fine particle motor emissions ranged from 9.6 x 104 to 3.34 x 108 particles/min, which were estimated to be 0.028 to 176 mg/min for mass emissions, respectively. The vast majority of particles released were in the range of 0.3-0.5 mm in diameter. The lowest particle emission rate was obtained for a vacuum cleaner that had a high efficiency (HEPA) filter placed after the vacuum cleaner bag and the motor within a sealed exhaust system. This vacuum cleaner removed the KC1particles that escaped the vacuum cleaner bag and the particles emitted by the motor. Results obtained for the KC1 collection efficiency tests show >99% of the fine particles were captured by the two vacuum cleaners that used a HEPA filter. A series of tests conducted on two vacuum cleaners found that the motors also emitted ultra-fine particles above 0.01 mm in diameter at rates of greater than 108 ultra-fine particles/CF of air. The model that had the best collection efficiency for fine particles also reduced the ultra-fine particle emissions by a factor of 1 x 103.  相似文献   
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