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Polar anthropogenic organic micropollutants are frequently detected in freshwater and discharged on large scale into marine systems. In this work the results of 153 samples collected from the shorelines of the Baltic Sea (Germany), Northern Adriatic Sea (Italy), Aegean Sea and Dardanelles (Greece & Turkey), San Francisco Bay (USA), Pacific Ocean (USA), Mediterranean Sea (Israel), and Balearic Sea (Spain) are presented. The samples were analyzed for various classes of micropollutants such as pharmaceuticals, corrosion inhibitors, biocides, and stimulants. Caffeine, paraxanthine, theobromine, tolyltriazole, 1H-benzotriazole, and atrazine were detected in >50% of all samples. The detection frequencies of carbamazepine, iopamidol, diuron, sulfamethoxazole, paracetamol, theophylline, and atenolol were between 20% and 32%. As caffeine is linked to untreated wastewater, the widespread occurrence of raw sewage in marine environments and thus potentially elevated nutrient concentrations and risk for the presence of wastewater-related pathogens is remarkable. 相似文献
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The western sector of the Tagliamento River basin (Friuli Venezia-Giulia Region; northern Italy) is characterized by important water resources, both superficial and underground. In particular, in the Quaternary deposits of the plain, up to a depth of 500 m, six artesian aquifer systems exist. A large amount of lithological, geomorphological, and hydrogeological data is presented, allowing for definition of (a) the principal aquifer system of the area to a depth of about 500 m; (b) geometrical characteristics of the aquifers (thickness, lateral extension, etc); (c) the hydraulic parameters (hydraulic conductivity, transmissivity); (d) chemico-physical characteristics of the water; and (e) vulnerability to pollution of the aquifer systems. In a test area, where many boreholes were drilled for fresh water supply, the conceptual hydrogeological model was integrated by a detailed and repeated three-dimensional (3D) resistivity survey using combined electrical resistivity tomography (ERT) and time-domain electromagnetic (TDEM) soundings. ERT investigation was mainly used to get detailed information about geometry and porosity of the overburden and to calibrate the shallowest TDEM information. 相似文献
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Abstract Industrial land development has become a key feature of urbanization in Greater Jakarta, one of the largest metropolitan areas in Southeast Asia. Following Suharto's market-oriented policy measures in the late 1980s, private developers have dominated the land development projects in Greater Jakarta. The article investigates the extent to which these private industrial centers have effectively reduced the domination of Jakarta in shaping the entire metropolitan structure. The analysis indicates that major suburban industrial centers have captured most of the manufacturing employment that has dispersed from Jakarta. The industrial centers have now increasingly specialized and diversified. It is likely that a polycentric metropolitan structure will emerge in the future. 相似文献
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Robert G. Mann Seb Oliver Ruth Carballo Alberto Franceschini Michael Rowan-Robinson Alan F. Heavens Maria Kontizas David Elbaz Anastasios Dapergolas Evanghelos Kontizas Gian Luigi Granato Laura Silva Dimitra Rigopoulou J. Ignacio Gonzalez-Serrano Aprajita Verma Steve Serjeant reas Efstathiou Paul P. van der Werf 《Monthly notices of the Royal Astronomical Society》2002,332(3):549-574
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This paper examines the eigenvalues of multi‐span seismically isolated bridges in which the transverse displacement of the deck at the end abutments is restricted. With this constraint the deck is fully isolated along the longitudinal direction, whereas along the transverse direction the deck is a simple‐supported beam at the end abutments which enjoys concentrated restoring forces from the isolation bearings at the center piers. For moderate long bridges, the first natural period of the bridge is the first longitudinal period, while the first transverse period is the second period, given that the flexural rigidity of the deck along the transverse direction shortens the isolation period offered by the bearings in that direction. This paper shows that for isolated bridges longer than a certain critical length, the first transverse period becomes longer than the first longitudinal period despite the presence of the flexural rigidity of the deck. This critical length depends on whether the bridge is isolated on elastomeric bearings or on spherical sliding bearings. This result is also predicted with established commercially available numerical codes only when several additional nodes are added along the beam elements which are modeling the deck in‐between the bridge piers. On the other hand, this result cannot be captured with the limiting idealization of a beam on continuous distributed springs (beam on Wrinkler foundation)—a finding that has practical significance in design and system identification studies. Finally, the paper shows that the normalized transverse eigenperiods of any finite‐span deck are self‐similar solutions that can be represented by a single master curve and are independent of the longitudinal isolation period or on whether the deck is supported on elastomeric or spherical sliding bearings. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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The chemical and hydrodynamic characteristics of groundwater in deltaic regions are strongly influenced by the complex stratigraphy of these areas, caused by the continuously varying depositional environments associated with their recent hydrographic evolution. As a case study, the eastern sector of the Po River plain, northern Italy, has been investigated to understand the quality of the available groundwater resources. Based on the analysis of hydrochemical and isotopic data, the recharge characteristics, the groundwater residence time and the aquifer vulnerability are defined. The results show significant qualitative degradation of the unconfined aquifer due to the shallow depth to water, while in the underlying confined aquifer, a hydrochemical facies of Ca–HCO3 type prevails. The spatial variation and relationship between oxygen-18 and deuterium determine: firstly, hydraulic separation of the two hydrogeological units; secondly, direct infiltration of local precipitation to the unconfined aquifer; thirdly, the occurrence of waters originating in the Alps and locally from the Apennines, pervading the confined aquifer. The tritium results suggest local mixing between the superficial waters and the confined aquifer, occurring along the palaeo-river channels. This increases the pollution vulnerability of the confined hydrogeological unit within the plain, which is the only natural groundwater resource exploited for water supply. 相似文献
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A simple algorithm is proposed in order to transform routine surface wind speed observations near the coast to a wind at the height of the equilibrium planetary boundary layer as well as to any other height over a relatively flat coastal region. The model is based on the well known internal boundary layer (IBL) concept, Monin-Obukhov similarity theory and the resistance law, and describes the effects of the roughness transition from sea to land as well as the effect of stability on the shape of the profiles and the IBL growth. The required input weather data are no more than surface wind speed, air temperature and total cloud cover. Satisfactory agreement was found between measurements at Hellinikon airport and estimations made with the scheme. The introduction of a transition layer above the IBL did not improve the agreement to any significant extent. Mean values of the estimated wind differed by less than 1 m s -1 from the observed ones, a difference within the accuracy of the reported rawinsonde values. The rms error varied in the range of 17–22% of the observed average value, giving the best agreement under unstable conditions. The correlation coefficient between the observed and the estimated values of the wind, at the height of the equilibrium planetary boundary layer, ranged between 0.74 and 0.90. 相似文献
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Konstantinos Chassapis Maria Roulia Dimitra Tsirigoti 《International Journal of Coal Geology》2009,78(4):288-295
Lignite samples from two deposits located in the Megalopolis Basin, Southern Greece, were evaluated for their potential applicability as raw materials for the production of organomineral fertilizers. Fundamental chemical analyses were carried out to demonstrate high humic substances and metal contents. To determine their relative distribution in the Megalopolis lignite extract, eight elements, namely Na, K, Cd, Mn, Mg, Pb, Zn, and Cu, were studied both in H2O and in Na4P2O7/NaOH solutions. The behavior of these metals showed significant variations; Zn, Pb, Cd, and Cu associate mostly to the humic substances and proved scarce in the water extract. Contrarily, K and Mg gave a significantly low total yield in the Na4P2O7/NaOH solution, while Mn was classified among the least extracted elements. Further enrichment of Megalopolis humic substances in these metals was achieved; Pb and Mg proved the most and least retained metal, respectively. Decomplexation titration curves of humic matter saturated with these metal ions demonstrated that novel organomineral fertilizing materials may develop based on optimized metal ion and humate contents, which can retain metals in a soluble form within a wide pH range. Formation of complexes between humic substances and Zn, Cd, and Mg was clearly indicated. 相似文献