206 research outputs found

    Aspects of Land Take in the Metropolitan Area of Naples

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    Land take is a phenomenon of great concern nowadays because of the large number of its negative impacts regarding biological, economic and social balance. In Italy, the development of urban and other artificial land has been irreversibly transforming a nonrenewable resource such as soil, regardless the almost constant population rate, with different speed depending of the region considered. The aim of this paper is to analyze the phenomenon in the metropolitan area of Naples, which is an area highly affected by territorial aggression of human matrix. The data used are both by the Institute for Environmental Protection and Research (ISPRA) Report 2015 on the usage of the land and by ISTAT relating to the resident population up to the 1st of January 2015 and the extension of land for agricultural use (Census 2010). The mathematical combination of this data creates a new indicator that can be referred to as “residual land”; this residual area is of great extension with many different characteristics and it could represent the area where the phenomenon of land take most occurs. The identification, measurement and analysis of “residual land” provide new insights on the evolution of land take and this new indicator can represent a critical element to work on to prevent future land transformation and protect natural and agricultural areas within the Italian context

    Opers versus nonabelian Hodge

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    For a complex simple simply connected Lie group GG, and a compact Riemann surface CC, we consider two sorts of families of flat GG-connections over CC. Each family is determined by a point u{\mathbf u} of the base of Hitchin's integrable system for (G,C)(G,C). One family ∇ℏ,u\nabla_{\hbar,{\mathbf u}} consists of GG-opers, and depends on ℏ∈C×\hbar \in {\mathbb C}^\times. The other family ∇R,ζ,u\nabla_{R,\zeta,{\mathbf u}} is built from solutions of Hitchin's equations, and depends on ζ∈C×,R∈R+\zeta \in {\mathbb C}^\times, R \in {\mathbb R}^+. We show that in the scaling limit R→0R \to 0, ζ=ℏR\zeta = \hbar R, we have ∇R,ζ,u→∇ℏ,u\nabla_{R,\zeta,{\mathbf u}} \to \nabla_{\hbar,{\mathbf u}}. This establishes and generalizes a conjecture formulated by Gaiotto.Comment: 23 page

    Traffic pollution modelling in a complex urban street

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    This study explores for the first time, the applicability of the Danish Operational Street Pollution Model (OSPM) in the city of Buenos Aires where street canyons are very irregular. The model is applied in an irregular and asymmetric street canyon of a five-lane avenue near a street intersection. Urban background concentrations estimated by the DAUMOD model are considered. Meteorological information registered at the domestic airport located in the city is used in calculations. Three months of hourly NOx, NO 2 and CO estimated concentrations are compared with measurements inside the street canyon. Statistical evaluation of model results shows that OSPM performance is quite good.Fil: Venegas, Laura Esperanza. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad TecnolĂłgica Nacional; ArgentinaFil: Mazzeo, Nicolas Antonio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad TecnolĂłgica Nacional; Argentin

    Study of natural and traffic-producing turbulences analysing full-scale data from four street canyons

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    Parameters related with natural and traffic producing turbulences are estimated for four street canyons considering all wind directions. Available data include air pollution concentrations measured in Göttinger Strasse (Hannover, Germany), Schildhornstrasse (Berlin, Germany), Jagtvej (Copenhagen, Denmark) and Hornsgatan (Stockholm, Sweden), background pollution, wind speed and direction measured on the roof of a nearby building and information of traffic flow. Results show that coefficients a and b, related to natural- and traffic- produced turbulences, vary with wind direction. The variation of critical wind speed with traffic density and wind direction is also studied for each street canyon.Fil: Mazzeo, Nicolas Antonio. Universidad Tecnológica Nacional. Facultad Regional Avellaneda; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Venegas, Laura Esperanza. Universidad Tecnológica Nacional. Facultad Regional Avellaneda; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Hourly NOXconcentrations and wind direction in the vicinity of a street intersection

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    This study relates NOxconcentrations and wind (speed and direction) measured inside an asymmetric street canyon, with ambient wind. The monitoring site is located near a street intersection. The wind measured at the domestic airport located in the city, near the coast, has been considered as ambient wind. Wind direction at the monitoring site inside the canyon is mainly from the E, NE, W and NW for any ambient direction. In general, the behaviour of horizontal airflow at the monitoring site for different ambient wind directions seems to be quite similar to those observed at other street intersections reported in the literature.Fil: Mazzeo, Nicolas Antonio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad TecnolĂłgica Nacional; ArgentinaFil: Venegas, Laura Esperanza. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad TecnolĂłgica Nacional; Argentin

    EVALUATION OF NATURAL AND TRAFFIC-PRODUCING TURBULENCES USING FULL SCALE DATA FROM FOUR STREET CANYONS

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    In urban areas, high air pollutant concentrations may be observed, mostly within street canyons, where buildings and other obstacles disturb the airflow and turbulence. Air motions inside the street canyons are influenced by aerodynamic and thermal effects and by the movements of the vehicles. Parameters related with natural and traffic produced turbulences are estimated for four street canyons considering all wind directions. Available data used include air pollution concentrations measured in Göttinger Strasse (Hannover, Germany), Schildhornstrasse (Berlin, Germany), Jagtvej (Copenhagen, Denmark) and Hornsgatan (Stockholm, Sweden), and background pollution, wind speed and direction measured on the roof of a nearby building and information of traffic flow. For each street canyon, the variation with traffic density of critical wind speed (that equals the contributions of turbulent motions related to wind and traffic to the effective velocity variance inside the street canyon) is also studied

    Air pollution in a street canyon estimated considering different parameterisations of vehicle-induced turbulence

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    Leeward air pollutant concentrations (C) are estimated by incorporating four parameterisations of traffic-produced turbulence (TPT) into the scaling of C inside a street canyon. Three parameterisations consider expressions previously introduced by other authors, based on a theoretical formulation of TPT and a semi-empirical approach already incorporated in an operational street model. The fourth scheme introduces an empirical expression of TPT derived from four full-scale street canyon datasets. Hourly NOx concentrations are calculated for an asymmetric street canyon in Buenos Aires, using meteorological observations at local airport and modelled background concentrations. Statistical indicators show that the performance of the four schemes is satisfactory.Fil: Mazzeo, Nicolas Antonio. Universidad TecnolĂłgica Nacional. Facultad Regional Avellaneda. Departamento de IngenierĂ­a QuĂ­mica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Venegas, Laura Esperanza. Universidad TecnolĂłgica Nacional. Facultad Regional Avellaneda. Departamento de IngenierĂ­a QuĂ­mica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Dezzutti, Mariana Clara. Universidad TecnolĂłgica Nacional. Facultad Regional Avellaneda. Departamento de IngenierĂ­a QuĂ­mica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentin

    Controlling non-radiative energy transfer in organic binary blends: a route towards colour tunability and white emission from single-active-layer light-emitting devices

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    We show how colour tunability (including white) can be achieved by controlling non-radiative intermolecular energy transfer from the donor to the acceptor in binary blends of oligomeric compounds. Blends of different concentrations of a novel functionalized thiophene-based oligomer and a low-molar-mass diamine derivative (N, N'-diphenyl-N, N'-bis(3-methylphenyl)-1, 1'-biphenyl-4.4'diamine) are used to tune both the photoluminescence and the electroluminescence (EL) from red to blue, including balanced white, according to the standards of the Commission Internationale de l'Eclairage. The single-active-layer light-emitting devices, realized by spin-coating, exhibit good EL performance. In particular, the white-emitting device shows an EL efficiency of 5 × 10−1 cd A−1 and a luminance of more than 180 cd m−2
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