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321.
This paper deals with sustainability in cities and the role technology plays in furthering sustainable results. Recently, many interventions have been implemented in cities to propose paths and models promoting the sustainability of cities from an overall perspective. Technologies are favouring the achievement of aims recalling the three spheres of sustainability as proposed by Arcadis (2017), namely “planet”, “profit”, and “people”. The ties between technology and the three spheres are investigated through a content analysis of reports issued by the 10 cities with the most significant advances in terms of becoming sustainable cities, as indicated in the Arcadis Report 2016. The results highlight technology as an element crossing sustainability, as processes and models in cities management and service provisions to citizens are significantly changing. New tools are innovating the processes addressing environmental issues, thus leading to cost efficiency and better economic conditions. Parallel to this, new models for city management and the provision of public services are addressing the need for a better quality of life for citizens and cities’ other stakeholders. Technology itself is thought of as sustainable because it should lead to efficiency and being efficient itself. A qualitative cluster analysis and a focus on excerpts from reports are proposed to highlight the ties between technologies and the elements representing key issues in managing and leading a city towards more sustainable conditions.  相似文献   
322.
323.
Concentrations of Cd and As were determined in organs and tissues (muscle, heart, kidney, lung and liver) of four cetacean species (Stenella coeruleoalba, Truncatus truncatus, Grampus griseus and Ziphius cavirostris) stranded along the Italian coasts during the period 2000-2009. Significant differences were found between Cd concentrations in the different analysed tissues. Particularly, the kidney shows the highest concentrations of Cd in all analysed specimens, followed by the liver. No systematic or statistically significant difference in As concentrations was found in the analysed tissues. Considerable differences of Cd and As values in samples from different geographical areas (Sicily Channel, Adriatic Sea and Tyrrhenian Sea) were found, with the highest values measured in samples from the Sicily Channel. This basically suggests that anthropogenic and natural sources significantly affect Cd and As content in cetaceans.  相似文献   
324.
The relationship between Secchi disc depth and amount of suspended material in seawater varies depending on the particular marine area. To identify the cause of this dependence, we calculated the apparent contrast (C SD) at each Secchi disc depth in different coastal sea areas. When the turbidity from the surface to the Secchi disc depth was uniform, the C SD was distributed in the range of 1.3 to 0.001 for a Secchi disc depth (Z SD) of 2–18 m. Z SD tended to decrease as C SD became larger. The dominant wavelength for the sea color was 475–500 nm for a Secchi disc depth of 13–18 m, and 500–575 nm for a ZSD of 2–6 m, shifting to longer wavelengths as the Secchi disc depth increased. That is, when Z SD decreased, the dominant wavelength of the sea color, and the C SD increased simultaneously. This phenomenon seems to occur because the contrast threshold for the human eye is higher at longer wavelengths. In other words, the contrast threshold is visibly indistinguishable when the apparent contrast in ocean waters with low Secchi disc depths is high. This phenomenon occurs because the human eye is affected by the color of the sea.  相似文献   
325.
Water samples collected from public drinking water supplies in Sicily were analysed for electric conductivity and for their chloride, sulphate and nitrate contents. The samples were collected as uniformly as possible from throughout the Sicilian territory, with an average sampling density of about one sample for every 7,600 inhabitants. Chloride contents that ranged from 5.53 to 1,302 mg/l were correlated strongly with electric conductivity, a parameter used as a proxy for water salinity. The highest values are attributable to seawater contamination along the coasts of the island. High chloride and sulphate values attributable to evaporitic rock dissolution were found in the central part of Sicily. The nitrate concentrations ranged from 0.05 to 296 mg/l, with 31 samples (4.7% of the total) exceeding the maximum admissible concentration of 50 mg/l. Anomalous samples always came from areas of intensive agricultural usage, indicating a clear anthropogenic origin. The same parameters were also measured in bottled water sold in Sicily, and they all were within the ranges for public drinking water supplies. The calculated mean nitrate intake from consuming public water supplies (16.1 mg/l) did not differ significantly from that of bottled water (15.2 mg/l). Although the quality of public water supplies needs to be improved by eliminating those that do not comply with the current drinking water limits, at present it does not justify the high consumption of bottled water (at least for nitrate contents).  相似文献   
326.
In this paper, the global agricultural land use model Kleines Land Use Model is coupled to an extended version of the computable general equilibrium model (CGE) Global Trade Analysis Project in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implication for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on the biophysical aspects of land into a state-of-the-art CGE; it further allows the projection of resulting changes in cropland patterns on a spatially more explicit level. A convergence test and illustrative future simulations underpin the robustness and potentials of the coupled system. Reference simulations with the uncoupled models emphasise the impact and relevance of the coupling; the results of coupled and uncoupled simulations can differ by several hundred percent.
Francesco BoselloEmail: Email:
  相似文献   
327.
A numerical model for predicting the fate and transport of biodegradable polyester residues in soil, following successive applications of mulch film, was developed and applied. The polymer, applied on surface soil, was assumed to be converted into by-products (monomers), according to a first order kinetics with constant K(1deg). The monomers released were assumed to sorb on soil organic matter (according to a first-order kinetics with constant K(s)), to be leached with the seepage water, through vertical advection and hydrodynamic dispersion, and biodegraded (according to a first-order kinetics with constant K(b)). Results suggested that, to assess a possible build-up of mulch film (as a polymer) on the surface soil, the degradation constant K(1deg) relating the polymer conversion to by-products should be known, whereas the biodegradation constant K(b) indicates there is no danger of groundwater pollution. Likewise, on the basis of by-product concentration in deep soil, soil pollution should not occur.  相似文献   
328.
Landfilling is nowadays the most common practice of waste management in Italy in spite of enforced regulations aimed at increasing waste pre-sorting as well as energy and material recovery. In this work we analyse selected alternative scenarios aimed at minimizing the unused material fraction to be delivered to the landfill. The methodological framework of the analysis is the life cycle assessment, in a multi-method form developed by our research team. The approach was applied to the case of municipal solid waste (MSW) management in Rome, with a special focus on energy and material balance, including global and local scale airborne emissions. Results, provided in the form of indices and indicators of efficiency, effectiveness and environmental impacts, point out landfill activities as the worst waste management strategy at a global scale. On the other hand, the investigated waste treatments with energy and material recovery allow important benefits of greenhouse gas emission reduction (among others) but are still affected by non-negligible local emissions. Furthermore, waste treatments leading to energy recovery provide an energy output that, in the best case, is able to meet 15% of the Rome electricity consumption.  相似文献   
329.
This work analyses cadmium sorption by natural vermiculite, zeolite, and pumice, which have been recently considered for their potential use in remediation of contaminated soils. Batch experiments were performed to investigate the interactions between the mineral surfaces and the main nutritive cations of Hoagland solution. In addition to their ameliorative effect of reducing metal mobility, these minerals are able to interact to different extents with various components of the nutrient solution and can change the availability of essential nutrients in solution. Therefore, the minerals were also exposed to a range of cadmium doses to compare their different affinities for this element and to analyse the cadmium–nutrient interactions. The results showed that the nutrient solution composition was significantly modified by contact with zeolite and vermiculite, and to a minor extent with pumice. The ionic equilibrium between the solid and aqueous phases was attained at several time points depending on the cation. Ammonium and potassium ions were almost entirely absorbed by zeolite, while in vermiculite endogenous magnesium ions were exchanged with the liquid phase calcium ions. The amount of cadmium adsorbed on mineral surfaces equilibrated with the nutrient solution showed the following sequence zeolite>vermiculite>pumice, and the cation concentrations of the fluid phase were sensitive to cadmium addition.  相似文献   
330.
The effects of agricultural activities on the environment can be presented by suitable pressure indicators. These pressure indicators can also be used as control variables to achieve a desired environmental state. Therefore, pressure indicators can play a decisive role in the elaboration of agri-environmental measures. This paper deals with the use of pressure indicators to assess the sustainability of agricultural land use on the one hand, and their contribution to the development of agri-environmental measures on the other hand. After the illustration of the general political background on the CAP evolution and the information needed for monitoring, control and ex-post assessment, the methodological approach of the AEMBAC project to provide this information is presented. Experiences in applying pressure indicators in assessing the agri-environmental measures are discussed and their applicability for the identification of environmental impacts, management and monitoring is evaluated.  相似文献   
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