National University of La Plata

About: National University of La Plata is a education organization based out in La Plata, Argentina. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 12993 authors who have published 30013 publications receiving 495118 citations. The organization is also known as: UNLP & Universidad Nacional de La Plata.

Indoor-outdoor distribution and risk assessment of volatile organic compounds in the atmosphere of industrial and urban areas.

Abstract: Volatile organic compounds (VOCs), which play an important part indoors and outdoors, comprise differing compound groups such as n-alkanes, cycloalkanes, aromatic and chlorinated hydrocarbons and terpenes. In the current study, samples were analyzed from indoor (schools and houses, n = 92) and outdoor (n = 33) air in urban, industrial, semirural and residential areas from the region of La Plata (Argentine) to consider VOC exposure in different types of environments. VOCs were sampled for 1 month during winter for 3 years, with passive 3M monitors. Samples were extracted with CS(2) and analyzed by GC/MS detectors. The results show significant differences in concentration and distribution between indoor and outdoor samples, depending on the study area. Most VOCs predominantly originated indoors in urban, semirural and residential areas, whereas an important outdoor influence in the industrial area was observed. In all areas alkanes and aromatic compounds dominated, even though a different chemical distribution was seen. Traffic burden was determined as the major source of outdoor VOC with a benzene/toluene ratio close to 0.5. Indoors, C9-C11 alkanes, toluene and xylenes dominated, caused by human activities. In contrast, in the industrial area higher concentrations of hexane, heptane and benzene occurred outdoors and affected the indoor air significantly. The lifetime cancer risk (LCR) associated to the benzene exposure was calculated for children from the different study areas. For all groups the study showed a LCR value greater than 1 x 10(-6) related to the benzene exposure indoors as well outdoors. A value two magnitudes higher was detected indoors in the industrial area, what demonstrates the high risk for children living in this area of La Plata.

Measurement of the prompt J/ψ pair production cross-section in pp collisions at √s = 8 TeV with the ATLAS detector

Abstract: The production of two prompt $J/\psi$ mesons, each with transverse momenta $p_{\mathrm{T}}>8.5$ GeV and rapidity $|y| < 2.1$, is studied using a sample of proton-proton collisions at $\sqrt{s} = 8$ TeV, corresponding to an integrated luminosity of 11.4 fb$^{-1}$ collected in 2012 with the ATLAS detector at the LHC. The differential cross-section, assuming unpolarised $J/\psi$ production, is measured as a function of the transverse momentum of the lower-$p_{\mathrm{T}}$ $J/\psi$ meson, di-$J/\psi$ $p_{\mathrm{T}}$ and mass, the difference in rapidity between the two $J/\psi$ mesons, and the azimuthal angle between the two $J/\psi$ mesons. The fraction of prompt pair events due to double parton scattering is determined by studying kinematic correlations between the two $J/\psi$ mesons. The total and double parton scattering cross-sections are compared with predictions. The effective cross-section of double parton scattering is measured to be $\sigma_{\mathrm{eff}} = 6.3 \pm 1.6 \mathrm{(stat)} \pm 1.0 \mathrm{(syst)} \pm 0.1 \mathrm{(BF)} \pm 0.1 \mathrm{(lumi)}$ mb.