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251.
The utility of potentiometric techniques applied to environmental problems is discussed. The applicability of this technique to the estimation of thermodynamic quantities important for the modelling of uranium migration in natural waters is demonstrated. An experimental methodology for the determination of the UO2(s) solubility product and the UO2+/U4+ redox potentials is proposed.  相似文献   
252.
The commercial captive breeding of wildlife is often seen as a potential conservation tool to relieve pressure on wild populations, but laundering of wild‐sourced specimens as captive bred can seriously undermine conservation efforts and provide a false sense of sustainability. Indonesia is at the center of such controversy; therefore, we examined Indonesia's captive‐breeding production plan (CBPP) for 2016. We compared the biological parameters used in the CBPP with parameters in the literature and with parameters suggested by experts on each species and identified shortcomings of the CBPP. Production quotas for 99 out of 129 species were based on inaccurate or unrealistic biological parameters and production quotas deviated more than 10% from what parameters in the literature allow for. For 38 species, the quota exceeded the number of animals that can be bred based on the biological parameters (range 100–540%) calculated with equations in the CBPP. We calculated a lower reproductive output for 88 species based on published biological parameters compared with the parameters used in the CBPP. The equations used in the production plan did not appear to account for other factors (e.g., different survival rate for juveniles compared to adult animals) involved in breeding the proposed large numbers of specimens. We recommend the CBPP be adjusted so that realistic published biological parameters are applied and captive‐breeding quotas are not allocated to species if their captive breeding is unlikely to be successful or no breeding stock is available. The shortcomings in the current CBPP create loopholes that mean mammals, reptiles, and amphibians from Indonesia declared captive bred may have been sourced from the wild.  相似文献   
253.
Environmental Science and Pollution Research - The nutrient biological removal from sewage, especially from anaerobic reactor effluents, still represents a major challenge in conventional sewage...  相似文献   
254.
The Landfill Allowance Trading Scheme (LATS) is one of the main instruments used in England to enforce the landfill diversion targets established in the Directive 1999/31/EC of the European Parliament and of the Council of 26 April 1999 on the landfill of waste (Landfill Directive). Through the LATS, biodegradable municipal waste (BMW) allowances for landfilling are allocated to each local authority, otherwise known as waste disposal authorities (WDAs). The quantity of landfill allowances received is expected to decrease continuously from 2005/06 to 2019/20 so as to meet the objectives of the Landfill Directive. To achieve their commitments, WDAs can exchange, buy, sell or transfer allowances among each other, or may re-profile their own allocation through banking and/or borrowing. Despite the goals for the first seven years – which included two target years (2005/06 and 2009/10) – being widely achieved (the average allocation of allowances per WDA was 22.9% higher than those finally used), market activity among WDAs was high and prices were not very stable. Results in terms of waste reduction and recycling levels have been satisfactory. The reduction of BMW landfilled (in percentage) was higher during the first seven years of the LATS period (2005/06–2011/12) (around 7% annually) than during the previous period (2001/02–2004/05) (4.2% annually). Since 2008, the significance of the LATS diminished because of an increase in the rate of the UK Landfill Tax. The LATS was suppressed after the 2012/13 target year, before what it was initially scheduled. The purpose of this paper is to describe the particularities of the LATS, analyse its performance as a waste management policy, make a comparison with the Landfill Tax, discuss its main features as regards efficiency, effectiveness and the application of the “polluter pays” principle and finally discuss if the effect of the increase in the Landfill Tax is what made the LATS ultimately unnecessary.  相似文献   
255.
Riparian habitats are important for the maintenance of regional biodiversity. Many studies have compared bird distributions between riparian and non-riparian habitats but have not established how wide riparian habitats used by birds are, as measured by distance from the nearest stream. We investigated the distribution of understory birds along gradients of distance from streams, soil clay content, and slope in a central Amazonian forest, by mist-netting birds three times in 45 plots. We used nonmetric multidimensional scaling (NMDS) to reduce the dimensionality of species quantitative (abundance) and qualitative (presence-absence) composition to one multivariate axis. Estimates of the width of riparian habitats as indicated by understory birds depended on the community attribute considered, measuring 90 m for species quantitative composition and 140 m for species qualitative composition. Species distributions were correlated with clay content but were independent of slope, while distance from streams was positively correlated with clay content but independent of slope. Clay content affects plant species composition, which in turn, may influence bird species composition. However, distribution patterns of birds in relation to distance from streams are consistent among studies carried out in many different temperate and tropical regions, indicating an effect of distance from streams itself. Protection of riparian habitats is one of the most widely used conservation strategies, and Brazilian environmental legislation mandates the protection of a 30 m wide strip of riparian vegetation on either side of small streams. We show that the protected strip should be much wider and recommend strategies to place other forms of land protection contiguous with riparian areas so that Brazilian environmental legislation better fulfills its role of protecting biodiversity associated with riparian habitats.  相似文献   
256.
The problem of toxic smoke in case of an accident with fire scenario is particularly severe in long tunnels and immediate effects from combustion product exposure often include fatalities. Notwithstanding extensive studies on fire simulation in tunnel, there is still a substantial lack of information on the different toxic products from combustion of light or heavy vehicles. In particular, there is a need for reliable test methods suitable to provide toxic products yields connected to defined accidental fire scenarios. In this paper, experimental runs in a laboratory scaled tunnel, simulating accidental fires of different heat release rates allowed firstly to characterize the thermal profiles in pool and car fires and to compare results by an analytical pool fire model. Results were compared as well with those obtained in a real scale tunnel, so as to quantitatively assess the scaling effect. A series of experiments was performed simulating an accidental scenario including pool fire from collision between a light vehicle and a HazMat heavy vehicle. An extensive set of experimental data allowed performing with good accuracy and reproducibility a complete characterization of toxic gases from car model fires, together with carbon monoxide and oxygen trends. The results obtained under different heat release rates allowed evidencing the dependence of the yields of toxic gases upon the considered scenario. Based on the intrinsic toxicity data of identified compounds, it is possible to draw practical conclusions, useful to assess the potential hazard associated to exposure to toxic smoke in road tunnel.  相似文献   
257.
This paper considers the role of social networks in the non-market valuation of public goods. In the model individuals derive utility both from their own direct enjoyment of the public good and from the enjoyment of those in their network. We find that network structure almost always matters, both for utility and for valuation. The network increases aggregate valuation when it assigns higher importance, that is, stronger connections, to individuals with higher private values for the public good. The model provides a theoretical foundation for the idea of opinion leaders who have disproportionate influence over their communities. Specifically, opinion leaders are individuals assigned high importance by the network, and projects favored by opinion leaders tend to be favored by the network as a whole. The model can also guide future empirical studies by enabling a more structural approach to non-market valuation in a socially connected group.  相似文献   
258.
This paper deals with the problem of defining the operational tasks, modelling and optimizing of antifire crew and their attempts. Unwanted events are generally modest and easily controlled in their starting phase. This obviously leads to considering that quickness and coordination enhance the possibility of successful fire control. Hence the importance that the first intervention of the factory antifire crew is supported by strong organization and efficiency. Immediate and appropriate response to emergency is essential to minimize severity of accidents, life losses, as well as the potential reduction in the plant future productivity. In approaching internal antifire crew optimization, it is convenient to distinguish a traditional inventory phase, a subsequent optimization and a graphic modelling phase. Optimization criterion is developed according to graph theory, with regard to intervention pathways and to consistency of antifire crew. The proposed graphic model provides, in an immediately readable way, the sequence of operator actions to be followed in order to cope with emergency situations.  相似文献   
259.
260.
This article presents a short overview of selected recent papers using nuclear magnetic resonance (NMR) to investigate interactions between organic pollutants and soil components such as organic matter, clays, whole soils, and sediments. First, we describe solid state cross polarisation magic angle spinning (CP-MAS) experiments as the main tools to investigate covalent bonds. Second, we report NMR approaches allowing us to assess molecule mobility and to characterise non-covalent interactions. Those approaches include correlations between K oc values and soil organic matter functions determined by CP-MAS, 2H NMR fingerprints, relaxation time measurements, 19F and 1H high resolution (HR)-MAS experiments.  相似文献   
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