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81.
82.
The aim of our article is to follow how global policy models affect local policy making. Each city has unique local challenges in promoting development, e.g. economic growth, but also needs to find a balance between these targets and demands for sustainable city solutions. In our empirical study, we follow how ideas of waterfront development – to attract new inhabitants and promote economic growth – and global demands of carbon control were used interactively in a strategic spatial planning process in the city of Tampere, Finland. During the six-year planning process, these two policy targets became interdependent, created a new policy-making domain, and led to a combinatorial development of sustainability elements arising from this domain. These findings demonstrate the serial use of global policy models in the creation of a local urban ‘sustainability fix’. To conclude, the intertwinement of diverse global policy models in a city planning process creates easily a recursive cycle that redefines urban sustainability within cities and intercity networks. This perspective makes local policy narratives and strategic planning highly important in urban sustainability research as promoting urban sustainability becomes an inherently ambivalent practice.  相似文献   
83.
The steel industry is characterised by large amounts of CO2 emissions, but there is no easy means to reduce these emissions. One interesting option for the reduction of CO2 emissions could be the utilisation of steelmaking slags for carbon dioxide mineralisation. In this option CO2 is bound with the calcium of the slag material, producing stable carbonate as an end product. The utilisation of steelmaking slags as the raw material for carbon dioxide mineralisation will change the quality of the slags. If, however, this change degrades the slags it could prevent the use of slags in carbon dioxide mineralisation or make it very expensive.The purpose of the research presented here is to evaluate this issue with the help of a case study where the quality of the residual slag from the recently suggested carbonation method was experimentally investigated. The CO2 mineralisation method, based on steelmaking slags and ammonium salt solutions, was found to change the quality of the slags: the calcium content was reduced, the CaO and Ca(OH)2 phases were completely dissolved, and the solubility of the V and Cr increased notably. This residual slag would presumably have to be handled as waste. Currently, the steelmaking slag used in the case study is defined as a by-product, but if it is used for CO2 mineralisation instead of liming its legal status will be re-evaluated. Subsequently, the CO2 mineralisation process could possibly be defined as an end-of-waste procedure.  相似文献   
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In many temperate estuarine areas, ongoing climatic changes are expected to lead to higher seawater temperatures, to increased inflow of freshwater and nutrients (due to increased rainfall) and to altered light conditions. During the last two decades, several winters have been unusually mild in southern Finland, and the subsequent springs have been early. This may have consequences for the seasonality of many species, including the bladder-wrack, Fucus vesiculosus, whose reproductive cycle may be especially sensitive. In the present study, F. vesiculosus receptacles from the field were weighed regularly during three warm (early) springs and compared with receptacles from three cold (late) springs. On average, the first sign of receptacle growth in the field occurred 5–6?weeks earlier and receptacles probably matured 2–3?weeks earlier during the warm springs than during the cold springs. This may be due to differences in seawater temperatures among years, but significantly heavier receptacles at 0.8?m compared to at 3.1?m further suggests the importance of light for receptacle growth as a measure of maturation, since there were no depth-related differences in seawater temperatures. Also, when plotting receptacle wet weights against seawater temperatures, the importance of light can be seen as different regression relationships (slopes and intercepts). In an outdoor aquarium experiment, the effects of temperature and light on receptacle growth were also tested, and there were significant differences between shallow and deep specimens, but temperature and light had no effects, except on initial receptacle growth. Since oogonian development, and thereby the time for zygote release, followed the receptacle growth curve, this could mean a mismatch between the timing of F. vesiculosus zygote settlement and the cover of competing filamentous algae, but such species interactions require further investigations in order to better understand their possible consequences.  相似文献   
86.
The distribution of cadmium and arsenic in rainwater, surface soil and groundwater in a zone of influence of emissions of a phosphate fertilizer factory has been investigated. The analysis of rainwater along a wind line shows that cadmium in the soluble form precipitates close to emission source, whereas arsenic migrates further and also in the soluble form precipitates at a greater distance. The pH controls the distribution of cadmium and arsenic in rain and groundwater. Concentration of soluble cadmium along the impact line increases with reduction of pH and arsenic, contrary to the increase of pH. Concentrations of cadmium and arsenic in surface soil correlate well among themselves near to emission point. In a zone of confluence of emissions with sea air at a distance from the factory there is sedimentation of arsenic on a geochemical barrier and formation of a separate anomaly in soil.  相似文献   
87.
A pilot study was conducted to determine the feasibility of using constructed treatment wetlands to remediate recovered groundwater from the subsurface of a former refinery site. The pilot system consisted of four subsurface flow treatment cells operated in an upward vertical flow mode and equipped with subsurface aeration lines. The treatment system showed minimal capability for methyl-tert-butyl ether removal, but did effectively remove total petroleum hydrocarbons-deisel range organics and total benzene, toluene, ethylbenzene, and o-, m-, and p-xylenes (total BTEX). Effluent benzene concentrations were less than 0.05 mg/L in 70% of the samples from a treatment cell using subsurface aeration and a wetland sod amendment. Based on 1 year of operating data, cumulative mass removal approached 80% for benzene and 88% for total BTEX.  相似文献   
88.
89.
In old, spruce-dominated forests of central Finland, Eurasian treecreepers Certhia familiaris divide their territories spatially during the breeding season. Females forage primarily on the upper parts of the tree trunks, while males use the lower parts of the tree trunks. In this study we removed males from eight territories in the early nestling period to see if the mate's absence would change the foraging patterns of the resident female. Widowed females foraged at lower heights, thus behaving more like paired males. These females also spent less time on each tree and on each foraging bout than did paired females. We conclude that male removal facilitated the change in a female's foraging niche and foraging time at the trees. Females may re-optimize their foraging site selection owing to the absence of dominant males and a consequent need to increase their parental care. Behavioral plasticity may be the mechanism of niche partitioning between the sexes in this species. Received: 28 June 1996 / Accepted after revision: 27 March 1997  相似文献   
90.
When exploiting forest resources, the resource use must be sustainable if its use is to support its function in the natural ecosystem. The African mahogany, a prized timber species, is widely exploited, raising policy concerns about the management of forest resources to meet the social, economic, and ecological needs of present and future generations. This paper explores, for the purpose of policy implication, the relationship between the exportation and deforestation of African mahoganies. The analysis employed a Granger causality test within the error correction model to evaluate the direction of causality between African mahoganies exports and deforestation in Ghana. The results suggested that in the short run, there was significant (P < 0.01) unidirectional causality from African mahoganies exports to deforestation. However, there was no directional causality from deforestation to mahogany exports. Thus, mahogany extraction and logging in general are among the major factors contributing to deforestation in Ghana. The general assessment of historical trends in the extraction levels of the two main genera of African mahoganies revealed that Entandrophragma cylindricum and Khaya ivorensis have been the most exploited species over the years. Improvements in, and the enforcement of, existing forest institutions and incentives, as well as related policies, could minimise the rate of deforestation not only of the African mahogany but also in timber logging, thus stemming forest degradation and deforestation in the country.  相似文献   
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