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81.
Harold H. Nielsen 《Die Naturwissenschaften》1930,18(27):620-622
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In many Asian cities the public water supply is characterised by low pressure, frequent interruptions and occasional contamination. Hence, private households have to store water and increase pressure individually to ensure an uninterrupted supply at sufficient pressure and water for drinking has to be boiled or supplied separately in bottles. In this study the present water supply system in Hanoi and a number of modification options were analysed from an environmental point of view through life cycle assessment (LCA) in order to identify the most sustainable solutions for future water supply. It was found that the boiling of water for drinking was the largest source of impacts in the present system. Impacts could be reduced significantly if the public supply network was improved and private pumping and storage could be avoided and if the water could be used directly for drinking. It was also found that impacts could be reduced if consumers used bottled water for drinking instead of boiling tap water. Finally, it was demonstrated that even if drinking water cannot be supplied directly through the public network, a reliable public water supply at high pressure is environmentally advantageous. Sensitivity analyses revealed that the conclusions of this study are likely to be applicable to other cities with similar water supply systems. 相似文献
85.
Conservation operates within complex systems with incomplete knowledge of the system and the interventions utilized. This frequently results in the inability to find generally applicable methods to alleviate threats to Earth's vanishing wildlife. One approach used in medicine and the social sciences has been to develop a deeper understanding of positive outliers. Where such outliers share similar characteristics, they may be considered exceptional responders. We devised a 4‐step framework for identifying exceptional responders in conservation: identification of the study system, identification of the response structure, identification of the threshold for exceptionalism, and identification of commonalities among outliers. Evaluation of exceptional responders provides additional information that is often ignored in randomized controlled trials and before–after control‐intervention experiments. Interrogating the contextual factors that contribute to an exceptional outcome allow exceptional responders to become valuable pieces of information leading to unexpected discoveries and novel hypotheses. 相似文献
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Marine Elbakidze Kjell Andersson Per Angelstam Glen W. Armstrong Robert Axelsson Frederik Doyon Martin Hermansson Jonas Jacobsson Yurij Pautov 《Ambio》2013,42(2):160-173
This paper analyzes how sustained yield (SY) forestry is defined and implemented in Sweden and Russia, two countries with different forest-industrial regimes. We first compare definitions of SY forestry in national legislation and policies. Then we study forest management planning in two large forest management units with respect to: delivered forest products and values, how the harvest level of timber is defined, where the harvest takes place, and what treatments are used to sustain desired forest products and values. In Sweden SY forestry is maximum yield based on high-input forest management, and in Russia it is forestry based on natural regeneration with minimum investments in silviculture. We conclude that how SY forestry contributes to SFM depends on the context. Finally, we discuss the consequences of SY forestry as performed in Sweden and Russia related to its ability to support diverse forest functions, as envisioned in sustainable forest management policy. 相似文献
87.
Models to Assess the Risk of Snow and Wind Damage in Pine, Spruce, and Birch Forests in Sweden 总被引:2,自引:0,他引:2
3 are damaged annually by snow and wind, roughly corresponding to a value of US$150 million, and in Europe, the damage amounts
to hundreds of millions of US dollars each year. To help to reduce these losses, tools for risk assessment within forest management
have been developed. Predictions were developed of the risk of damage from snow and wind to Scots pine (Pinus sylvestris L.), Norway spruce [Picea abies (L.) Karst.] and Birch (Betula spp. L.) plots using tree, stand, and site characteristics. The data were obtained from 6756 permanent sample plots within
the Swedish National Forest Inventory, which were inventoried twice at five-year intervals between 1983 and 1992. Input data
for model development used measurements from the first inventory of tree characteristics for the largest sample tree, stand,
and site data, and records of snow and wind damage from the second inventory. Models were developed for three different regions
for pine- and spruce-dominated sites, while models for the whole country were developed for birch sites. In general the estimated
proportion of damaged plots was highly overestimated (31.7%–56.2%), compared with the observed proportion of 3.4%–11.9%. The
models for Norway spruce comprising tree, stand, and site data show the best predictability of damaged plots, with 60.6%–67.6%
of plots correctly classified. It is concluded that the models developed can be used to detect sites with a high probability
of damage from snow and wind, and thus be used as tools to reduce future damage and costs in practical forestry. 相似文献
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Simões Marta Filipa Maiorano Alfredo Eduardo dos Santos Jonas Gomes Peixoto Luciana de Souza Rodrigo Fernando Brambilla Neto Almir Oliveira Brito António Guerreiro Ottoni Cristiane Angélica 《Environmental Chemistry Letters》2019,17(3):1413-1420
Environmental Chemistry Letters - The anthraquinone dye Remazol Brilliant Blue R is largely used in the textile industry. However, its removal from wastewaters is costly and complex. Many methods... 相似文献
90.
Jens Borum Ane Løvendahl Raun Harald Hasler-Sheetal Mia Østergaard Pedersen Ole Pedersen Marianne Holmer 《Marine Biology》2014,161(2):351-358
Distinct ‘fairy rings’ consisting of narrow fringes of eelgrass (Zostera marina L.) expand radially over a bottom of chalk plates outside the calcium carbonate cliffs of the island of Møn, Denmark. We conducted a survey to evaluate possible explanations for the formation of the rings and, more specifically, for the apparent die-off of eelgrass shoots on the inner side of the rings. The fairy rings were up to 15 m in diameter consisting of 0.3- to 1-m-wide zones of sea grass shoots at densities of up to 1,200 shoots m?2 and rooted in an up to 10-cm-thick sediment layer. On the outer side, shoots expanded over the bare chalk plates. On the inner side, shoots were smaller, had lower absolute and specific leaf growth, shoot density was lower and the sediment eroded leaving the bare chalk with scattered boulders behind. Sediment organic matter and nutrients and tissue nutrient contents were not different among positions. Sediment pools of acid volatile sulfides and chromium-reducible sulfur increased from outer to the middle positions of the rings, and so did total sulfur content of eelgrass tissues, while tissue δ34S isotope ratios, regardless of position in the fringes, were low reflecting substantial invasion of sulfide from the sediment. Neither the clonal growth pattern of eelgrass, sediment burial of shoots, hydrodynamic forcing nor nutrient limitation could explain the ring-shaped pattern. We conclude that the most likely explanation must be found in invasion of eelgrass shoots by toxic sulfide accumulating in the sediment due to low iron availability in the carbonate-rich environment. 相似文献