A study on atmospheric aerosol particles size distribution in several sites in Lombardia region by an optical particle counter

In Lombardia, a project (Particolato fine in Lombardia \u2013 PARFIL \u2013 2004\uf72006) aiming at the chemical and physical characterisation of atmospheric aerosol related with pollution sources is in progress. Sixteen measurement sites with different topography and urbanization are continuously monitored as for PM10/PM2.5/PM1 mass concentration and chemical composition. Moreover, particle number concentration was assessed at five sites (2 urban, 1 rural, 1 pre-alpine and 1 alpine) using an Optical Particle Counter (OPC) working on 15 classes over the size range 0.3\u201330 \ub5m. In each site both winter and summer campaigns were performed. In order to investigate similarities in the behaviour of different sized particles, cluster analysis was applied on the dimensional classes. The autocorrelation function was determined on the clusters to estimate particles residence times and/or response time to variation of the system on local scale. Number concentration series were also analysed in relation to main meteorological parameters as air temperature and humidity, atmospheric pressure, wind speed and direction, rainfall and Pasquill categories. The results of the study highlight the role played by local sources for the coarse fraction, while meteorological conditions, seasonal changes and pollution emissions on the Po valley have a significant influence on the sub-micron sized particles

Virtual Reality-Based Training: Case Study in Mechatronics

This paper introduces, explains and illustrates real-life application of virtual training tool for electrical engineering education. The tool gives users the opportunity to interact with and manipulate 3D models of authentic devices. The users have a possibility to compare structural differences between devices, assemble and disassemble the machines and test them under extreme conditions, all of which would not be possible while working with a real device. The 3D devices are fully operational allowing the users to interact with them on every level, including analysis of impact of supply conditions i.e. modify voltage and frequency of a particular motor and monitor changes in performance while still operating. The main goal of this research was to evaluate effectiveness and educational values of the proposed tool. Early studies and feedback from educators and students prove this tool to be a great assistance to process of education, facilitating knowledge acquisition and providing an innovative way to put theory into practice

β-Adrenergic response is counteracted by extremely-low-frequency pulsed electromagnetic fields in beating cardiomyocytes

Proper β-adrenergic signaling is indispensable for modulating heart frequency. Studies on extremely-low-frequency pulsed electromagnetic field (ELF-PEMF) effects in the heart beat function are contradictory and no definitive conclusions were obtained so far. To investigate the interplay between ELF-PEMF exposure and β-adrenergic signaling, cultures of primary murine neonatal cardiomyocytes and of sinoatrial node were exposed to ELF-PEMF and short and long-term effects were evaluated. The ELF-PEMF generated a variable magnetic induction field of 0-6mT at a frequency of 75Hz. Exposure to 3mT ELF-PEMF induced a decrease of contraction rate, Ca2+ transients, contraction force, and energy consumption both under basal conditions and after β-adrenergic stimulation in neonatal cardiomyocytes. ELF-PEMF exposure inhibited β-adrenergic response in sinoatrial node (SAN) region. ELF-PEMF specifically modulated β2 adrenergic receptor response and the exposure did not modify the increase of contraction rate after adenylate cyclase stimulation by forskolin. In HEK293T cells transfected with β1 or β2 adrenergic receptors, ELF-PEMF exposure induced a rapid and selective internalization of β2 adrenergic receptor. The β-adrenergic signaling, was reduced trough Gi protein by ELF-PEMF exposure since the phosphorylation level of phospholamban and the PI3K pathway were impaired after isoproterenol stimulation in neonatal cardiomyocytes. Long term effects of ELF-PEMF exposure were assessed in cultures of isolated cardiomyocytes. ELF-PEMF counteracts cell size increase, the generation of binucleated of cardiomyocytes and prevents the up-regulation of hypertrophic markers after β-adrenergic stimulation, indicating an inhibition of cell growth and maturation. These data show that short and long term exposure to ELF-PEMF induces a reduction of cardiac β-adrenergic response at molecular, functional and adaptative levels

The bakelite for the RPCs of the experiment CMS

Results from aging tests on the bakelite used for the CMS RPCs are presented. Samples of melaminic bakelite were exposed to a heavy gamma and neutron radiation. Data on the bulk resistivity were collected while accumulating gamma and neutron doses and particles fluence up to values well beyond those expected in 10 years of RPCs operation in the barrel region of CMS. The test with gamma radiation was performed at the CERN Gamma Irradiation Facility (GIF) with a 20 Ci /sup 137/Cs source. A total absorbed dose of 5 Gy was accumulated during an irradiation period of about one month. The test with both neutron and gamma radiation was held at the Triga Mark II 250 kW reactor located in Pavia. A total of 80 h of exposure were accumulated integrating a neutron and gamma dose of about 80 Gy and a fast neutron fluence of some 10/sup 11/ cm/sup -2/. Experimental data on dose rate in both the test facilities have been compared to simulation output and show a good agreement. (4 refs)