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It is well known that the incorporation of the intergenerational equity objective has turned the traditional Cost–Benefit Analysis (CBA) approach into an obsolete tool for the evaluation of certain types of projects, particularly those exhibiting many environmental externalities and those whose effects extend throughout a long period of time. Two main changes are taking place in CBA in order to adapt this methodology to the sustainable development paradigm: (a) the development of new tools for the economic valuation of environmental externalities that were traditionally left out of the analysis; and (b) an in-depth revision of the theoretical foundations underlying the traditional approaches to discounting, since the repercussions of decisions that are presently being debated will extend to a distant future (in some cases for centuries), whereas in the classical CBA, we deal with few decades at best. This paper aims at investigating the discounting operation in CBA, trying to summarize the main approaches available in the literature, with specific reference to the tools which allow future generations to be included in the analysis. In order to support the theoretical explanation, a real case study is analysed concerning the evaluation of a waste incinerator that has been constructed in the Province of Turin (Italy).  相似文献   
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Environmental Science and Pollution Research - The ability of tobacco (Nicotiana tabacum L. cv. Badischer Geudertheimer) for phytomanaging and remediating soil ecological functions at a...  相似文献   
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The Instituto de Radioprote??o e Dosimetria has been coordinating the National Intercomparison Program (PNI) for 15 years, from 1991 to 2005. The objective is to evaluate the analytical performance of the laboratories in low-level activity concentration radionuclide assays in environmental samples. This work presents an evaluation of PNI data from 42 intercomparison runs, which distributed to 22 Brazilian laboratories 2511 samples evaluating 5768 radionuclide assays involving 32 radionuclides in the period from 1991 to 2004. The laboratory performance was evaluated using the Normalized Standard Deviation used by the U.S. EPA. For comparison aims, the Normalized Deviation, used by BIPM was also applied. Laboratory performance were grouped and evaluated in three periods of 5 years each. The first period shows, an average value of good performance of 71.2%, the second shows an average of 78.6% and the last an average of 82.3%. Performance for each kind of radionuclide is also presented.  相似文献   
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Self-recruitment rates are essential parameters in the estimation of connectivity among populations, having important consequences in marine conservation biology. Using ten highly polymorphic microsatellite loci, we estimate, over 3 years, the self-recruitment in a population of Tripterygion delaisi in the NW Mediterranean. Six previously described source populations were used for the assignment (Costa Brava, Columbretes, Formentera, Cabo de Palos, Cabo de Gata and Tarifa). Even though this species has a 16–21 day larval duration, a mean of 66.4 ± 1.4% of the recruits settled in their natal population. When refining in a more local scale the origin of individuals self-recruited to Costa Brava, using as source the three sampling localities that conform this population (Cap de Creus, Tossa and Blanes), the highest percentage (40.6 ± 8.9%) was self-assigned to the adult source locality (Blanes) where recruits were sampled each year. Our results suggest that a high proportion of the larvae of T. delaisi remained close to, or never leave, their natal spawning area. This observation can be extrapolated to other species with similar early life-history traits and low adult mobility and can have important implications for the conservation and management of Mediterranean littoral fishes.  相似文献   
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The distribution of trace metals (Co, Cu, Fe, Mn, Ni, Pb and Zn) was investigated during a year (1994-95) in surface and core sediment samples and in the oyster (Crassotrea rhizophorae) from Bluefields Bay, Nicaragua. the aim was to assess the arthropogenic impact of potential pollutant sources, mainly Bluefields City, since domestic waste waters are discharged directly or by infiltration to the bay. Lyophilised samples were submitted to different acid digestion methods and analysed by flame atomic absorption spectrophotometry. the results showed highest contents for copper, lead and zinc near Bluefields City, with an increase in the affected area in the rainy season that is generated by greater city run off. Metal contents in oysters do not show the same distribution pattern than in sediments and were similar to those from other areas without reflecting pollution levels.  相似文献   
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Blends of LDPE/modified starch were prepared, sterilized by gamma radiation and investigated with respect to their microbial degradation by a mixture of fungal strains in liquid medium after 90 days, was analyzed by carbon dioxide (CO2) production (Sturm test). Biodegradation of blends was evaluated by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction; mechanical testing, scanning electron microscopy (SEM). The biodegradation of LDPE/modified starch blends was attributed to microbiological attack, with alterations in the chemical structure of the blend with an increase in the carbonyl and vinyl indices and the appearance of new crystalline symmetry generating a crystalline domain not existing before in the blend and decrease in the mechanical properties.  相似文献   
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