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21.
Detailed studies on pollutants genesis, path and transformation are needed in agricultural catchments facing coastal areas. Here, loss of nutrients should be minimized in order to protect valuable aquatic ecosystems from eutrophication phenomena. A soil system N budget was calculated for a lowland coastal area, the Po di Volano basin (Po River Delta, Northern Italy), characterized by extremely flat topography and fine soil texture and bordering a network of lagoon ecosystems. Main features of this area are the scarce relevance of livestock farming, the intense agriculture, mainly sustained by chemical fertilizers, and the developed network of artificial canals with long water residence time. Average nitrogen input exceeds output terms by ~60 kg N ha?1 year?1, a relatively small amount if compared to sub-basins of the same hydrological system. Analysis of dissolved inorganic nitrogen in groundwater suggests limited vertical loss and no accumulation of this element, while a nitrogen mass balance in surface waters indicates a net and significant removal within the watershed. Our data provide multiple evidences of efficient control of the nitrogen excess in this geographical area and we speculate that denitrification in soil and in the secondary drainage system performs this ecosystemic function. Additionally, the significant difference between nitrogen input and nitrogen output loads associated to the irrigation system, which is fed by the N-rich Po River, suggests that this basin metabolizes part of the nitrogen excess produced upstream. The traditionally absent livestock farming practices and consequent low use of manure as fertilizer pose the risk of excess soil mineralization and progressive loss of denitrification capacity in this area.  相似文献   
22.
Environmental Agencies require Decision Support Systems, in order to plan Air Quality Policies considering the cost of emission reduction measures and the human health effects (with related social costs). The use of Decision Support Systems is also useful to spread information to general public, explaining the effectiveness of proposed air quality plans. In this paper, a multi-objective approach to control PM10 concentration at a regional level is presented. The problem considers both the internal costs (due to the implementation of emission reduction measures) and the external costs (due to population exposure to high PM10 concentrations). To model PM10 concentrations, a single surrogate model is used for the entire domain, allowing the implementation of a very efficient optimization procedure. The surrogate model is derived through a set of 10 simulations, performed using a Chemistry Transport Model fed with different emission reduction scenarios. The methodology is applied to Northern Italy, a region affected by very high PM10 concentrations that exceed the limit values specified by the EU legislation.  相似文献   
23.
An enterprise can modify several factors that impact on the Occupational Health and Safety (OHS) performance. Within the implementation of the E-merging project (financed by INAIL, the Italian National Institute for Insurance against Occupational Accidents) – to improve safety in Small- and Medium-sized Enterprises (SMEs) – development context, a thorough literature review, supported by later practitioners’ suggestions, has been performed in order to identify the factors which can be related to the OHS issue. Then, the mutual interactions among the identified OHS-related factors and the interactions among the OHS-related factors and the OHS performance have been identified for SMEs and tested on the basis of two existing data sources, i.e. the INAIL most recent dataset and a survey carried out among SMEs in the metalworking industry. This allows to understand the root causes of some evidences, which enables entrepreneurs and managers to plan interventions for the improvement of the OHS performance.  相似文献   
24.
25.
To assess the impact of three different emission reduction scenarios on PM10 concentrations in Northern Italy, the TCAM multiphase model has been applied in the framework of the CityDelta III-CAFE EU project. The considered domain, that is characterized by high urban and industrial emissions and a dense road traffic, due to frequently stagnating meteorological conditions is often affected by severe PM10 levels, far from the European standard regulations. The impact evaluation has been performed in terms of both yearly mean values and 50 g/m3 exceedance days for the 2004 Base Case simulation. The results show that the three selected emission reduction scenarios up to 2020 improve air quality all over the domain, in particular, in the area with higher emission density.  相似文献   
26.
The heterogeneous photocatalytic degradation of pentachlorophenol (PCP) in aqueous solutions containing a suspension of TiO2 leads to the quantitative formation of CO2 and HC1. The photodegradation has also been studied in other semiconductor dispersions such as ZnO, CdS, WO3, and SnO2. TiO2 appears the most efficient. Oxygen and water are essential ingredients in the complete mineralization of this pollutant found near pulp and paper industries. Experiments with sunlight show a promising route for the water treatment processes; the half life of PCP (initial concentration 4.5 × 10?5M) is about 8 minutes, in the presence of 2 g/l of TiO2.  相似文献   
27.
The velvet belly Etmopterus spinax (Linnaeus, 1758) is a deep water bottom-dwelling species very common in the western Mediterranean sea. This species is a portion of the by-catch of the red shrimps and Norway lobsters otter trawl fisheries on the meso and ipo-bathyal grounds. A new, simple, rapid, and inexpensive vertebral preparation method was used on a total of 241 specimens, sampled throughout 2000. Post-cranial portions of vertebral column were removed and vertebrae were prepared for ageing readings. Band pair counts ranged from 0 to 9 in females, and from 0 to 7 in males. Von Bertalanffy growth equations estimated for both sexes suggested a higher longevity for females (males: L = 394.3 mm k = 0.19 t 0 = −1.41 L 0 = 92.7 mm A 99 = 18.24 years; females: L = 450 mm k = 0.16 t 0 = −1.09 L 0 = 72 mm A 99 = 21.66 years). Age estimations are discussed in the context of deep water shark species. This is the first successful attempt at delineating faint growth bands in the poorly calcified deep coned vertebrae of E. spinax. This technique may be used in other difficult poorly calcified species.  相似文献   
28.
The extraction kinetic of trace metals (Cd, Cu, Pb, and Zn) in river sediments by four extraction agents was studied. As extractants ammonium acetate, acetic acid, hydroxylamine and EDTA solutions were assayed. These reagents can leach the metals more or less selectively from several metal compartments of sediments. The metal leaching kinetic model permits classification of the metal species in labile and moderately-labile ones. The combination of two or more non specific reagents permits a high characterisation of metal distribution and leachability. The results obtained with this model in four river sediments were compared with data obtained by the SM&T sequential extraction procedure, in order to characterise the chemical nature of leached metal.  相似文献   
29.
The aim of the study was to assess the value of sonographic measurement of fetal humerus and femur lengths in the second trimester as a screening tool for Down syndrome (DS). We reviewed retrospectively fetal sonographic biometry made at the time of amniocentesis between 15 and 19 weeks. The study group consisted of 27 DS fetuses. The control group comprised 500 normal fetuses chosen randomly. The expected humeral and femoral lengths for a given biparietal diameter were estimated by linear regression equations from the 500 normal fetuses. Receiver operating characteristic curve analysis was performed to evaluate both the detection rate and the false-positive rate of different cut-off values of measured to expected lengths ratios. The median femur and humeral lengths in DS fetuses were 0·91 times the expected values. No significant differences in the detection rate and false-positive rate were found between the humerus and femur lengths. When the humeral and femoral lengths were combined, we observed a remarkable reduction in the false-positive rate. A measured to expected length ratio of 0·91 detected 44·4 per cent of DS fetuses with 7·6 per cent false positives. These results suggest that the combination of femoral and humeral lengths may permit a more efficient use of ultrasound in screening for Down syndrome than the use of either alone.  相似文献   
30.
High PM10 concentrations can cause human health problems, both related to short-term and long-term exposure to particles. In this work the impact of efficient PM10 control problems in Northern Italy is assessed by means of a two-stage methodology. In the first stage a multi-objective optimization approach is applied. The multi-objective problem defines two control objectives (the emission reduction costs and the air quality index) to be minimized varying the decision variables (precursor emission reductions). The solution of the multi-objective problem is the Pareto efficient PM10 control policies. In the second stage, the ExternE methodology is applied to estimate health impacts and external costs for the efficient emission reduction scenarios computed in the first stage. The methodology has been applied over Lombardia region, one of the most polluted areas in Europe.  相似文献   
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