Perfluorinated compounds in blood of Caretta caretta from the Mediterranean Sea     

Cristiana Guerranti  Stefania Ancora  Nicola Bianchi  Guido Perra  Emiliano Leonida Fanello  Simonetta Corsolini  Maria Cristina Fossi  Silvano Ettore Focardi 《Marine pollution bulletin》2013

Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14 ng/g to 28.51 ng/g (wet wt.). No differences between groups of samples taken from different areas were found.  相似文献   

Reactive Transport Modeling of ZVI Column Experiments for Nickel Remediation     

Stefania Bilardi  Richard T. Amos  David W. Blowes  Paolo S. Calabrò  Nicola Moraci 《Ground Water Monitoring & Remediation》2013,33(1):97-104

MIN3P, a multicomponent reactive transport model for variably saturated porous media, is used to simulate the outputs of column tests carried out using zero valent iron (ZVI) for nickel contaminated groundwater remediation. The objective of this study is to investigate the main chemical reactions involved in contaminant removal and the main causes of the reactivity decline of ZVI over time. According to the results of the model the major causes of ZVI reactivity loss is identified in the mineral precipitation of α‐FeOOH on iron surface that probably caused ZVI passivation and led to a decline of the electron transfer rate. An existing empirical relationship between mineral precipitation and the reactivity loss of ZVI, included in the model, reproduced the changes in nickel removal observed during different laboratory column tests.  相似文献   

PCDD/Fs in sediments of Central Vietnam coastal lagoons: in search of TCDD     

Piazza R  Giuliani S  Bellucci LG  Mugnai C  Cu NH  Nhon DH  Vecchiato M  Romano S  Frignani M 《Marine pollution bulletin》2010,60(12):2303-2310

Samples from nine Central Vietnam coastal lagoons, together with three soils and sediments collected in two freshwater reservoirs of the Thua Thien-Hué province, were analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Total concentrations are low, from 192 to 2912 pg g⁻¹ and depth profiles in Tam Giang-Cau Hai (TG-CH) sediment cores show only minor changes over time in PCDD/F input and composition. Octachloro dibenzo-p-dioxin (OCDD) is the prevailing congener (approximately 90%), indicating combustion as the main PCDD/F source to these coastal systems, whereas natural formation might be partly responsible for the presence at depth. 2,3,7,8-Tetrachloro dibenzo-p-dioxin (TCDD), largely sprayed together with Agent Orange over the study areas during the war (1961–1971), is absent or very low. This result supports the hypothesis of strong degradation soon after spraying. Multivariate statistical analyses account for the presence of local, short-range sources as observed in the northern part of the TG-CH lagoon.  相似文献   

Life and times of dwarf spheroidal galaxies     

Stefania Salvadori  rea Ferrara  Raffaella Schneider 《Monthly notices of the Royal Astronomical Society》2008,386(1):348-358

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Damage assessment of fortresses after the 2012 Emilia earthquake (Italy)   总被引：1，自引：1，他引：0  

Serena Cattari  Stefania Degli Abbati  Daniele Ferretti  Sergio Lagomarsino  Daria Ottonelli  Antonio Tralli 《Bulletin of Earthquake Engineering》2014,12(5):2333-2365

The medieval fortresses are a very common and distinctive type among the Emilian historical constructions and the earthquake of May 20 and 29, 2012 highlighted their high vulnerability. Starting from the analysis of the geometrical and constructive features, the interpretation of their seismic vulnerability has been based on an accurate damage assessment and supported by the numerical results of typical configurations. An abacus of recurring seismic damage mechanisms in fortresses has been proposed: it in particular concerns the towers and their interaction with the fortress perimeter walls. Moreover, the seismic response of the most important fortresses in the epicentral area has been described referring to their historical notes, the recent interventions and their influence on the seismic damage.  相似文献   

The impact of early dark energy on non-linear structure formation     

Margherita Grossi  Volker Springel 《Monthly notices of the Royal Astronomical Society》2009,394(3):1559-1574

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Wavy Vertical Motions in the ABL Observed by Sodar     

Igor Petenko  Giangiuseppe Mastrantonio  Angelo Viola  Stefania Argentini  Ilaria Pietroni 《Boundary-Layer Meteorology》2012,143(1):125-141

Some characteristics of wavelike motions in the atmospheric boundary layer observed by sodar are considered. In an experiment carried out in February 1993 in Milan, Italy, Doppler sodar measurements were accompanied by in situ measurements of temperature and wind velocity vertical profiles using a tethered balloon up to 600 m. The oscillations of elevated wavy layers containing intense thermal turbulence, usually associated with temperature-inversion zones, were studied by using correlation and spectral analysis methods. The statistics of the occurrence of wavelike and temperature-inversion events are presented. The height distributions of Brunt–Vaisala frequency and wind shear and their correlation within elevated inversion layers were determined, with a strong correlation observed between the drift rate of the wavy layers and the vertical velocity measured by Doppler sodar inside these layers. Spectral analysis showed similarities regarding their frequency characteristics. The phase speed and propagation direction of waves were estimated from the time delay of the signals at three antennae to provide estimates of wavelength. Moreover, wavelengths were estimated from the intrinsic frequency obtained from sodar measurements of the Doppler vertical velocity and oscillations of wavy turbulent layers. The two wavelength estimates are in good agreement.  相似文献   

Mobilization and loss of elements from roofing tiles     

Fazrul Razman Sulaiman  Peter Brimblecombe  Carlota M. Grossi 《Environmental Geology》2009,58(4):795-801

Deposition, leaching and chemical transformation are processes that affect roofing tile and roof runoff water. Leaching experiments, with artificial rainwater in the laboratory, showed the presence of Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl⁻, NO₃ ⁻, SO₄ ²⁻, with a ratio of Ca²⁺ and SO₄ ²⁻ suggesting gypsum dissolution. X-ray fluorescence (XRF) of the exposed roof tile showed depletion such as Mg, Al, Si, P, Ti and K at the surface of the tile and an enrichment of Fe and Mn which hinted at a process akin to laterite formation. However, calcium appeared to be enriched at the surface as gypsum (confirmed by X-ray diffraction) and to a lesser extent calcite, which is characteristic of deposits on building surfaces in cities.  相似文献   

Macroscopic motions in prominences     

Marcos E. Machado  Hugo Grossi Gallegos 《Solar physics》1972,23(2):340-345

Macroscopic velocity fields have been studied in a solar prominence. The spectra and monochromatic images were analyzed, and the existence of a contracting motion, possibly due to a pinch effect, is discussed. A helical shape of the prominence is proposed.  相似文献   

A critique of development and conservation policies in environmentally sensitive regions in Brazil     

Stefania Abakerli 《Geoforum》2001,32(4)

More than a strategy for environmental conservation, protected area paradigm has represented a specific conception of nature–society relationship. Originated in a context of capitalist consolidation, rapid urbanisation and frontier development in the US, this paradigm has given rise to a ‘politically viable rationale' in which utilitarian use of natural resources by tourism development would ensure nature preservation. This political rationality has deeply influenced environmental policies in developing countries, fostering a paradoxical model in the history of nature preservation. It also has brought into play diverse interests that have shifted patterns of local nature–society interaction, configuring a complex politicised environment. Established in ‘isolated' regions, protected areas have been implemented often by top–down approaches, disrupting resident peoples' livelihoods strategies through conflicts over the control of natural resources. Understanding the implications of development and conservation policies on resident peoples' livelihoods may represent a starting point for an integrated developmental conservation policy towards the promotion of sustainable livelihoods in environmentally sensitive regions in developing countries. These issues are analysed in the region of the Lençois Maranhenses National Park in Brazil. This paper argues that the context facing the region reveals a standardised conservationist paradigm marked by the absence of wider ecological criteria informing nature protection and a disregard for the strengthening of sustainability in existent socio-economic dynamics. The regional development and conservation policies have not only promoted tensions between resident peoples' livelihoods and the protected area paradigm, but also reinforced the legitimisation of social exclusion and environmental disruption under the prevalent rhetoric of nature protection and tourism development.  相似文献